DE102023108228A1 - heat exchanger of an adsorption dryer - Google Patents

Abstract

The invention relates to a heat exchanger for arrangement in a pressure vessel having a granular adsorption material of an adsorption dryer intended for drying a compressed gas, in particular compressed air, and for transferring heat from a heat transfer medium, in particular oil, to the granular adsorption material, with a heating section for transferring heat from the heat transfer medium to the adsorption material, and the heating section comprises a plurality of medium lines (1202, 1402), each having at least one medium channel, for guiding the heat transfer medium in the medium line, wherein the heating section has a substantially cylindrical shape with a longitudinal axis, the medium lines are arranged in the direction of the longitudinal axis in a plurality of line levels, the medium lines are designed and connected to one another in such a way that the heat transfer medium can flow through them together in parallel and/or in series, adjacent line levels and/or medium lines of adjacent line levels are spaced apart from one another in the direction of the longitudinal axis and the medium lines are designed as extruded profiles.

Description

The present invention relates to a heat exchanger for arrangement in a pressure vessel of an adsorption dryer. The present invention also relates to a corresponding adsorption dryer. The present invention also relates to a method for operating an adsorption dryer with a heat exchanger.

Rectangular heat exchangers are used for many applications, e.g. in the compressed air industry. There are various designs of the heat transfer elements of the heat exchanger. A material that is widely used in heat exchangers is aluminum or aluminum alloy. This material makes it possible to produce extruded profiles that have one or more internal channels and also have a relatively large surface area under economically attractive conditions. The wall thicknesses can sometimes be small, usually less than one millimeter. This results in short distances of heat conduction within the material. Such profiles are also known as "microchannel profiles."

One known use of such profiles can be, for example, to design a heat exchanger with several such microchannel profiles arranged parallel to one another, which are connected together at one end to a manifold and also connected together at the other end to a manifold. One manifold is connected to the fluid inlet, the other to the fluid outlet.

The individual microchannel profiles are connected in the gaps with fins in a heat-conducting manner. A fluid can flow through the inner channels of the profiles, and ambient air can flow around the profiles and fins. Such heat exchangers are used in the compressed air industry, for example, as condensers in refrigeration dryers.

In addition to heat exchangers made from microchannel profiles, there are other well-known concepts for the design of heat exchangers, such as those that use fins. Here, fins/sheets are positioned next to each other at intervals of a few millimeters, for example, and are interspersed with one or more tubes. While one fluid, e.g. water, flows through the tubes, the other fluid, e.g. air, flows around the surface of the tubes and the fins. Due to the large surface area of the fins, good heat exchange is possible here. Various materials can be used for such heat exchangers.

There are also heat exchanger designs that are suitable for a round installation space or can be suitably manufactured as a round component. Such well-known designs are, for example, coiled tube heat exchangers, which allow a long pipe section to be placed in a compact installation space.

Another well-known round heat exchanger design is a spiral heat exchanger. Here, two concentric flow channels are formed in a spiral shape, through which two media can flow separately from one another, for example in the countercurrent or crosscurrent principle.

The finned heat exchangers described above are also available in round versions, e.g. when used in conjunction with fans.

However, special requirements may arise for use in a modern regeneration plant, especially an adsorption dryer. Such an adsorption dryer can dry a compressed gas in a pressure vessel filled with desiccant. Such desiccant must be regenerated and a heat supply via a heat exchanger can be helpful for this. The heat supply through the heat exchanger should therefore take place within the desiccant. It may also be the case that heated compressor oil from a compressor of the adsorption dryer is used to supply heat, as in US 4,898,599 shown.

For the described regeneration mode with heat supply within the drying agent through the heated compressor oil, a heat exchanger with a special design is required to enable sufficient heat input into the regeneration air and the drying material. It is necessary to use a suitable material and geometry for the heat exchanger. In addition to a large surface area, a favorable flow through the regeneration air is also important.

The present invention is therefore based on the object of addressing at least one of the problems mentioned above. In particular, a solution is to be proposed in which a heat exchanger can be used for a described novel mode of operation of the regeneration operation with heat supply within the drying agent, in particular by heated compressor oil, in order to enable the highest possible heat input into the regeneration air and the drying agent. At least an alternative solution to previously known solutions is to be proposed.

According to the invention, a heat exchanger according to claim 1 is proposed. The invention therefore relates to a heat exchanger for arrangement in a pressure vessel. This has a granular adsorption material, which can also be referred to as a drying agent, and is intended for drying a compressed gas, in particular compressed air. The pressure vessel is part of an adsorption dryer. The heat exchanger is thus arranged in such a pressure vessel for transferring heat from a carrier medium, in particular oil, to the granular adsorption material. This transfer of heat to the granular adsorption material is provided in a regeneration operation.

The adsorption dryer works in such a way that drying and regeneration operations can alternate. The heat exchanger is then particularly active in regeneration mode and has a heating section for transferring heat from the heat transfer medium to the adsorption material. Basically, the entire heating section can be referred to as a heat exchanger, but in practice, in addition to the actual heating section in which the heat transfer takes place, there are also sections for connecting the heat exchanger and thus the heating section to supply or discharge lines. Fastening sections for fastening or at least fixing the heat exchanger or the heating section in the pressure vessel can also be added.

The heating section and thus of course also the heat exchanger comprises several medium lines, each having at least one medium channel, for guiding the heat transfer medium in the medium line, wherein the heating section essentially has a cylindrical shape with a longitudinal axis. The heating section therefore comprises not just one, but several medium lines in which the heat transfer medium is guided. In particular, oil, in particular oil from a pressure compressor, i.e. compressor oil, can be guided therein.

The cylindrical shape is understood to mean, in particular, a circular cylindrical shape. Naturally, slight deviations from an ideal circular shape are possible. In particular, it is proposed that the cylindrical shape of the heating section is based on the shape of the pressure vessel in order to be able to be pushed into or pulled out of the pressure vessel in the direction of the longitudinal axis.

The medium lines are arranged in several levels in the direction of the longitudinal axis. If the longitudinal axis is arranged vertically, several levels of lines are arranged one above the other. This means that heating can take place in these several levels of lines, thus achieving the most uniform possible heating within the pressure vessel.

The medium lines are designed and connected to one another in such a way that the heat transfer medium can flow through them in parallel and/or in series. For example, the medium lines can be arranged between two common manifolds and thus connected in parallel, with the heat transfer medium flowing in through one manifold, then flowing through all the medium lines and flowing out again at the other manifold. However, the medium lines can also be designed and connected to one another in such a way that the heat transfer medium first flows through one medium line and then from its outlet through the next medium line, and so on. A combination can also be provided, for example by flowing through two medium lines in parallel and then from their common outlet through the next two medium lines.

It is further proposed that adjacent line levels and/or medium lines of adjacent line levels are spaced apart from one another in the direction of the longitudinal axis. In particular, they can be spaced apart from one another in such a way that they are essentially completely surrounded by the adsorption material. The adsorption material can in particular be designed as a bulk material and can then be poured into the pressure vessel in which the heat exchanger or its heating section is already arranged. The adsorption material is then also poured into these gaps between medium lines that are adjacent in the longitudinal direction. Heat can then be evenly released from the medium lines to the adsorption material surrounding them.

It is also proposed that the medium lines are designed as extruded profiles. By using extruded profiles, a substantially arbitrary shape of the medium lines can be created and thus also specified. The medium lines can thus form at least one medium channel for guiding the heat transfer medium essentially independently of the external shape of the medium line. The medium channel can therefore be specified in such a way that it is well suited for guiding the heat transfer medium, in particular for guiding a corresponding oil. Independently of this, the external shape of the medium line can be specified in such a way that a good and uniform A complete transfer of heat to the adsorption material and also to a regeneration gas used to regenerate the adsorption material, in particular regeneration air, can be achieved. In this way, an overall suitable cross-section can be specified, which also achieves the required stability of the medium lines. The shapes specified in this way can be easily realized by an extrusion process, whereby a suitable material such as aluminum or an aluminum alloy can be used, which achieves good stability with good thermal conductivity.

By using extruded profiles, for example, with a round cross-section of the medium channels, or of one of the medium channels, a partially straight outer profile can be created in order to be able to easily attach heat conducting plates or fins to it.

Likewise, the use of an extruded profile can create a suitable cross-section that can withstand a pressure difference that occurs, particularly as a pressure difference in the pressure vessel. In the regeneration phase, an overpressure in the heat exchanger can also occur compared to a pressure in the pressure vessel, e.g. 11 bar as absolute pressure in the heat exchanger compared to an absolute pressure of e.g. 1 bar or even 0.3 bar in the pressure vessel.

A heat exchanger is therefore proposed which is very well suited for use in a pressure vessel of an adsorption drying device, wherein the heat exchanger can easily release heat to the adsorption material and to the regeneration gas flowing through for regeneration, in particular regeneration air, in a regeneration operation in which the adsorption material is dried, i.e. the adsorption material is regenerated. Already dried compressed gas, in particular already dried compressed air, can be used as the regeneration gas, in whole or in part. The corresponding heat can be supplied by an oil, in particular compressor oil.

According to the invention, a heat exchanger according to claim 2 is also proposed. For this, it is provided that the medium lines are provided with heat conducting plates. As a result, the heat from the medium lines can be better transferred to the adsorption material and the regeneration gas intended for drying the adsorption material, in particular regeneration air.

For this purpose, it is further proposed that the heat conducting plates are spaced apart such that a bed of granular adsorption material with a maximum grain size of up to 12 mm, preferably up to 8 mm and in particular up to 5 mm is possible between two adjacent heat conducting plates of the same medium line. This means that at least one adsorption material, i.e. drying agent, can be selected that has a maximum grain size of 5 mm. In simple terms, the largest grain of the adsorption material can have a diameter of 5 mm. The grain size can be defined by the equivalent diameter, namely the volume-equivalent sphere diameter. The grain size mentioned then refers to the diameter that a sphere with the same volume of the non-spherical grain would have. However, a different, but very similar definition is used here, in which the largest diagonal or the largest diameter is used as the grain size. The drying agent can be almost spherical, which is why the various definitions do not differ greatly.

Heat exchangers with fins are known that achieve very good heat transfer to the surrounding air or to another liquid or gaseous medium. However, it was recognized that a lot of heat should also be transferred directly to the adsorption material. Therefore, known filigree fins are not suitable. In addition, such filigree fins also run the risk of being damaged by the adsorption material, which is provided as bulk material.

It is therefore proposed to arrange heat conducting plates that are spaced apart from one another so that the granulate, i.e. the adsorption material, can also be poured between these heat conducting plates. In particular, it is proposed that the heat conducting plates are aligned vertically, relative to an arrangement with a vertical longitudinal axis. The heat conducting plates are therefore aligned parallel to the longitudinal axis.

Preferably, the heat conducting plates have a thickness of at least 0.08 mm, in particular at least 0.1 mm, in order not only to conduct heat well, but also to be sufficiently stable so as not to be damaged by a pouring of the adsorption material.

In addition or alternatively, it is proposed that adjacent heat conducting plates of the same medium line have a distance of at least 6 mm, preferably at least 9 mm and in particular at least 15 mm from each other. Such a distance can ensure that a granular adsorption material with the mentioned grain sizes can also be poured between the heat conducting plates.

The heat exchanger, in particular the heating section, is thus well adapted for use in a pressure vessel for the regeneration of an adsorption material of an adsorption dryer.

According to one aspect, it is proposed that in each of the line levels, exactly one at least partially circumferential line section of a medium line is provided, or at least two line sections of a medium line are arranged parallel to one another, with an intermediate distance between the line sections that is at least 6 mm, preferably at least 9 mm, in particular at least 15 mm and/or that allows a filling of granular adsorption material with a maximum grain size of up to 12 mm, preferably up to 8 mm, in particular up to 5 mm in the intermediate distance. Thus, either a single medium line is provided per level, or several, between which the adsorption material can be poured.

It is further proposed that the heating section has a circular shape and/or a circular outer contour and/or at least in sections a spiral shape in one of the line levels.

It was particularly recognized here that the pressure vessel into which the heating section is to be inserted should have a circular cylindrical shape in order to be able to withstand the corresponding pressure well. The shape of the heating section in the line levels is adapted to this. A circular shape and/or outer contour is therefore proposed. The use of a spiral shape is also very similar to such a circular shape. Although it deviates slightly from this and is not ideal in this respect, it does have the advantage that the medium flow through the medium lines can be guided in a simple manner in such a spiral shape, while at the same time several sections of a line level can run essentially parallel to one another. In particular, such a spiral shape can therefore fill the pressure vessel well and at the same time ensure a good medium flow, while at the same time good heat transfer from the heating section to the granular adsorption material.

According to one aspect, it is proposed that the heating section for arrangement in a pressure vessel with a circular cylindrical or annular gap-shaped interior has a curved outer contour adapted to the interior in each of the line levels.

Here too, a circular-cylindrical pressure vessel is proposed for good pressure absorption. However, it can also have a circular-cylindrical division inside, resulting in a circular-cylindrical annular gap. For this purpose, it is proposed that the heating section is adapted to this inner shape of the pressure vessel. The outer contour of the heating section in particular is adapted to this and preferably has a curved outer contour. This means that it is well adapted and can simultaneously achieve good flow of the heat transfer medium.

If an annular gap-shaped interior is provided, the heating section is adapted to this and thus has a cylindrical shell shape of a circular cylinder that can be inserted into such an annular gap. But even in this case, the heating section is designed in such a way that the granular adsorption material can be poured between the individual medium lines and/or heat conducting plates.

According to one aspect, it is proposed that the at least one medium channel has an average diameter and the medium line to the medium channel has a wall thickness and a ratio between the average diameter of the medium channel and the wall thickness is in the range of 2 to 50, in particular 5 to 25, and/or the wall thickness has a thickness of 0.15 mm to 2 mm, in particular 0.15 mm to 1.5 mm.

In particular, a circular medium channel can be assumed here, so that its diameter corresponds to the average diameter. If the shape is not circular, it can be the average between the largest and smallest diameter. The wall thickness is therefore the thickness of the wall between the medium channel and the outer contour of the medium line. In this case, the smallest wall thickness can be used as a basis.

It was particularly recognized here that the average diameter should be significantly larger than the wall thickness and that such a profile also achieves sufficient stability while at the same time achieving sufficiently good thermal conductivity from the medium channel to the outside. In particular, an average diameter of at least 5 times the wall thickness is suggested in order to achieve good flow properties for the heat transfer medium. This means that oil can also be used as a heat transfer medium and still flow well without causing too great a pressure drop in the heat transfer medium in the medium channel.

With a wall thickness of at least 0.15 mm, up to 2 mm, in particular 0.15 mm to 1.5 mm, a high stability of the medium line can be achieved, while at the same time good heat transfer.

According to one aspect, it is proposed that the medium lines each have an elongated cross-section which has a longitudinal dimension in the direction of the longitudinal axis of the heating section and a transverse dimension transverse thereto, wherein the longitudinal dimension is at least 1.5 times, in particular at least twice as large as the transverse dimension. The longitudinal dimension can also be referred to as the diameter of the medium line in the longitudinal direction and the transverse dimension can be referred to as the diameter of the medium line in a direction transverse to the longitudinal axis.

The cross-section of the medium line is such that the medium line presents only a very low flow resistance for the compressed gas or regeneration gas in the longitudinal direction, but has a larger area in the transverse direction that is suitable for releasing heat. The compressed gas or regeneration gas flows through the pressure vessel and thus also the heating section essentially in the longitudinal direction, i.e. along the longitudinal axis of the heating section, so that the medium line presents little flow resistance to this flow and can release a lot of heat at the same time.

Additionally or alternatively, the medium line has at least two medium channels running parallel to one another, wherein these at least two parallel medium channels are aligned and spaced apart in the direction of the longitudinal axis. If the longitudinal axis is arranged vertically, these medium channels are arranged one above the other. This also fits well with the elongated cross-section of the medium line, which is aligned in the longitudinal direction of the longitudinal axis, or such an arrangement of several medium channels leads to such an elongated cross-section. This means that the heat transfer medium can flow easily through the medium line, wherein the division into several medium channels promotes a laminar flow, while at the same time the medium line offers little flow resistance to the compressed gas flowing through the pressure vessel.

Despite the preferred design of multiple medium channels, in an alternative design it may also be advantageous to provide only one medium channel in the medium line. This allows the medium line to be designed in a simple manner and can also make it possible for more adjacent line levels to be possible in the pressure vessel. With more adjacent line levels, these can sometimes be better surrounded by the granular adsorption material, which achieves good heat transfer from the medium line to the adsorption material.

According to one aspect, it is proposed that the medium lines are designed as extruded profiles, in particular as aluminum and/or aluminum alloy. It was particularly recognized here that this makes it easy to manufacture the medium lines in the desired shape. In particular, they can be manufactured as described above and the relationships between the average diameter of the medium channel and the wall thickness described above can thereby be realized. The desired thickness of the wall thickness can also be realized in the manner described above.

The material aluminum or an aluminum alloy allows such an extrusion manufacturing process to be carried out well and at the same time good thermal conductivity is achieved, so that heat can be easily transferred from the carrier medium via the extruded profile to the environment, in particular to the granular adsorption material.

According to one aspect, it is proposed that the heating section has a plurality of manifolds and these manifolds comprise a supply channel for supplying the heat transfer medium and a discharge channel for discharging the heat transfer medium, wherein the supply channel and the discharge channel are each arranged parallel to the longitudinal axis and the medium lines are each arranged between the supply channel and the discharge channel, so that the heat transfer medium flows parallel through the medium lines from the supply channel to the discharge channel. The manifolds, which are particularly preferably designed as manifolds, thus connect a plurality of medium lines. It is possible that only the supply channel and the discharge channel are present as manifolds, but further manifolds can also be provided, for example to create further subdivisions and/or series connections between the medium lines.

The supply channel and the discharge channel are thus arranged parallel to each other and the medium lines are arranged between them. Basically, the supply channel and the discharge channel also connect the individual line levels. The supply channel and the discharge channel can also run adjacent to each other, with a distance that is less than an average diameter of each supply channel or at least less than twice or three times the diameter of the supply or discharge channel.

Particularly with a round arrangement of the medium lines, these can form a semicircle or an almost complete circle from the supply channel to the discharge channel. The heat transfer medium can thus be supplied and discharged in a simple manner via the supply channel and the discharge channel. This makes it possible to form the heating section in a simple and practical manner.

The supply channel and the discharge channel can also be continued linearly in order to lead them out of the pressure vessel.

Such a design of the heating section, whether with or without linear routing of the supply channel and the discharge channel, can also be easily inserted or removed in the longitudinal direction of the pressure vessel. Such a shape can be advantageous at least when inserting the heating section into a cylindrical pressure vessel.

According to one aspect, it is proposed that two medium lines adjacent to one another in the direction of the longitudinal axis are spaced apart from one another by a longitudinal distance that designates a free distance between them, wherein the longitudinal distance corresponds at least to a minimum thickness of the medium line. In other words, a minimum distance is provided between two medium lines in the longitudinal direction, and this distance is at least as large as the thickness of the medium line. If the medium lines are of different sizes, the thickness of the smaller medium line is used.

In particular, it is proposed that the longitudinal distance corresponds to at least twice the minimum thickness of the medium line and in particular to a maximum of 5 times the value of the minimum thickness of the medium line.

In particular, the minimum thickness of the medium line is taken into account here. If the medium line has an elongated cross-section and is aligned in the longitudinal direction, i.e. always in relation to the longitudinal axis of the heating section, this thickness is used, which is then measured transversely to the longitudinal axis. Two medium lines that are adjacent in the longitudinal direction therefore do not necessarily have to be as far apart as their own length in the longitudinal direction, but only have to be at least as far apart as they themselves are in the transverse direction.

The idea behind this is that the longitudinal distance, namely the free distance, i.e. how much space there actually is between the two medium lines, should be filled with adsorption material so that the medium lines are surrounded as well as possible by the adsorption material.

It has already been suggested above that the maximum grain size of the adsorption material should be used as the basis for such distances. It is also suggested here that the two longitudinally spaced and adjacent medium lines have such a distance from each other that the granular adsorption material fits through this free distance. The free distance will therefore preferably correspond to at least 1.2 times the largest grain size of the adsorption material.

However, it was recognized here that the medium lines are also based on the adsorption material used, in particular on the maximum grain size, and thus the size of the medium line is also a good measure of how large the distance between them should be. Therefore, a free distance is suggested here that is based on the minimum thickness of the medium line.

It can therefore be advantageous for the longitudinal distance to be at least twice the thickness of the medium line. This makes it possible to take into account in particular that the medium line has a very small thickness transverse to the longitudinal axis, so that the distance in the longitudinal direction between two adjacent medium lines should be at least twice as large. The longitudinal distance is preferably a maximum of 5 times the minimum thickness of the medium line. It was recognized here that a distance that is too large can be disadvantageous because, although a good filling of the granular adsorption material is achieved, the heat input is greatly impaired by the medium lines now being far apart. The free distance is therefore preferably in the range of twice to 5 times the thickness of the medium line.

According to one aspect, it is proposed that adjacent medium lines or adjacent medium line sections of the same line level are connected by heat conducting plates and/or several medium lines or several medium line sections are guided parallel to one another transversely through several heat conducting plates by which they are connected, or, if the medium lines are designed as extruded profiles, the extruded profiles do not have any heat conducting plates protruding from the extruded profile.

In other words, adjacent medium lines of the same line level are arranged next to one another in a horizontal plane if the longitudinal axis is vertical. They can be connected to heat conducting plates, which can be arranged in particular between them. Such heat conducting plates can be soldered on, for example, or provided in some other way, in particular in a material-bonded manner.

This allows good heat dissipation to be achieved because the heat conducting plates also dissipate the heat from the medium lines. In addition, a high level of stability is achieved in the relevant line level.

If the medium lines are arranged in a spiral, this would mean that the same medium line is connected to itself by the heat conducting plates, because the spiral shape means that it is essentially parallel to itself. In this case, at least several medium line sections are adjacent to one another. With the spiral shape mentioned, a particularly high level of stability can also be achieved by connecting to the heat conducting plates.

It is also possible that the heat conducting plates are provided by several medium lines being guided through these heat conducting plates at a distance from one another. With two medium lines arranged parallel to one another, each heat conducting plate can have two openings, e.g. two holes, and one of the medium lines is guided through each opening. This naturally creates contact between the heat conducting plates and the medium lines. In particular, a material connection between the heat conducting plates and the medium line can also be provided here. One possible way of manufacturing is to form a tubular section onto each plate for each medium line, i.e. two pipe sections for two parallel medium lines, and pipe sections of adjacent heat conducting plates are inserted into one another to form a medium line. In principle, a spiral arrangement or design of the medium line can also be considered here, although a corresponding manufacturing process would be comparatively complex.

If extruded profiles are used, it is particularly suggested that they are designed in such a way that the extruded profile already has a good outer contour for dissipating heat, so that heat conducting plates can be dispensed with.

• - wenigstens einem Druckbehälter mit
  • - einem Adsorptionsmaterial zum Adsorbieren von Feuchtigkeit aus dem Druckgas, das in den Druckbehälter eingefüllt ist,
  • - einem Trocknungseinlass zum Einlassen eines Druckgases zum Trocknen,
  • - einem Trocknungsauslass zum Auslassen des Druckgases nach dem Trocknen und
  • - einer Trocknungsstrecke, die das Druckgas in einem Trocknungsbetrieb vom Trocknungseinlass zum Trocknungsauslass durchströmt, und
• - wenigstens einem Wärmetauscher gemäß wenigstens einem der vorstehend erläuterten Aspekte, wobei
  • - von dem wenigstens einen Wärmetauscher jeweils der Heizabschnitt in dem Druckbehälter angeordnet ist und
  • - der Heizabschnitt jeweils von dem Adsorptionsmaterial umgeben ist, wobei das Adsorptionsmaterial als granulares Schüttgut ausgebildet ist.

According to the invention, an adsorption dryer is also proposed. The adsorption dryer is intended for drying a compressed gas, in particular compressed air. It is equipped with

• - at least one pressure vessel with
  • - an adsorption material for adsorbing moisture from the compressed gas filled into the pressure vessel,
  • - a drying inlet for admitting a compressed gas for drying,
  • - a drying outlet for discharging the compressed gas after drying and
  • - a drying section through which the compressed gas flows in a drying operation from the drying inlet to the drying outlet, and
• - at least one heat exchanger according to at least one of the aspects explained above, wherein
  • - of the at least one heat exchanger, the heating section is arranged in the pressure vessel and
  • - the heating section is surrounded by the adsorption material, wherein the adsorption material is in the form of granular bulk material.

The adsorption material is therefore intended to adsorb moisture from the compressed gas, with the adsorption material being filled into the pressure vessel. The adsorption of moisture takes place particularly in a work process in which compressed gas is passed through the compressed gas vessel and thus along the adsorption material for drying. Accordingly, the drying inlet is intended to let in the compressed gas for drying and the drying outlet to let the compressed gas out after drying. In between is the drying section in which the compressed gas is dried, while in the drying operation it flows through the drying section from the drying inlet to the drying outlet. For structural reasons and/or for functional tasks in particular, the pressure vessel cannot be completely filled with adsorption material. In this case, in the area of the drying inlet and/or the drying outlet, it has a transition area up to the adsorption material, in which no adsorption material is arranged. Each transition area can take up about 3%-10% of a length from the drying inlet to the drying outlet. The drying section is a section in the adsorption material, i.e. a section from the drying inlet to the drying outlet, minus at least one transition region.

The heat exchanger is thus intended for heating the adsorption material. For this purpose, the heat exchanger, at least with its heating section, is arranged accordingly in the pressure vessel. The heating section in particular has medium lines that are spaced apart in such a way that there is sufficient space between adjacent medium lines so that the granular adsorption material can be poured between such medium lines.

Thus, the heat exchanger according to the invention can be used in such an adsorption dryer. It is operated in particular in a regeneration mode or a regeneration phase in which the adsorption material that has absorbed moisture from the compressed gas is dried again. For this purpose, a compressed gas, such as compressed air, which has however been dried, can also be let into the pressure vessel. This can be done, for example, in the opposite direction to drying the compressed air, i.e. from the drying outlet back through the drying section to the drying inlet. All the advantages and features mentioned for the heat exchanger can be used when used in the adsorption dryer. Properties of the adsorption material, particularly the grain size, which were explained above in connection with aspects of the heat exchanger, can also be used here. In particular, the adsorption material can have a maximum grain size of up to 12 mm, preferably up to 8 mm, in particular up to 5 mm.

According to one aspect, it is proposed that the drying section has a first region facing the drying inlet and a second region facing the drying outlet, and the heating section is arranged in the first region in each case and in particular the heating section is not provided in the second region. The first and second regions are thus provided along the drying section and it is preferably provided that the first region extends over at least 20% of the drying section, preferably over at least 30% of the drying section, in particular over at least 40% of the drying section, preferably a maximum of 70%, in particular a maximum of 60% of the drying section. The heating section should be arranged in this region. In particular, it is provided that no heating takes place outside the heating region, or at most reduced heating with less than 30% energy input per volume, compared to the heating region.

The idea behind this is that the heating area is only needed in the regeneration phase. In the regeneration phase, it is assumed that a regeneration gas, in particular regeneration air, flows from the drying outlet to the drying inlet and thus initially flows through an area, namely the second area, without a heating section, and only later flows through an area with a heating section and thus with heating. Here it was recognized that the regeneration gas, i.e. the gas that flows through the pressure vessel to regenerate and thus dry the adsorption material, in particular regeneration air, is initially very dry when it flows in and can therefore easily absorb moisture from the adsorption material. In addition, with this arrangement it is to be expected that the adsorption material in the first area has absorbed more moisture than in the second area. In the second area less drying, i.e. less regeneration, is required. At the same time, the regeneration air itself is still very dry and can therefore absorb moisture better.

According to one aspect, it is thus proposed that a switching device is provided for switching between the drying operation and the regeneration operation, wherein in the regeneration operation a regeneration gas flows through the pressure vessel and the drying section from the drying outlet to the drying inlet in order to remove moisture from the adsorption material, and the first region is heated, while the second region is not heated or is heated to a lesser extent.

The regeneration gas can in particular be regeneration air, i.e. dry air. The regeneration gas then flows in the opposite direction compared to the drying operation. It therefore first reaches the adsorption material that the compressed gas to be dried last reached in the drying operation.

According to one aspect, it is proposed that the pressure vessel has an annular gap space and a cylindrical interior space surrounded by the annular gap space, wherein the annular gap space and the cylindrical interior space are connected to one another in such a way that the compressed gas for drying can flow from the drying inlet via the annular gap space further via the cylindrical interior space to the drying outlet, and the heating section of the heat exchanger is arranged in the annular gap space, or the compressed gas for drying can flow from the drying inlet via the cylindrical interior space via the annular gap space to the drying outlet, and the heating section of the heat exchanger is arranged in the cylindrical interior space.

This creates a solution in which both the compressed gas to be dried and the regeneration gas can also flow into the pressure vessel from the same side as it flows out, for example flow in from below and flow out downwards if the pressure vessel is positioned vertically. In particular, for dividing the pressure vessel so that the heating section is arranged in the annular gap, a circular heating section can be formed in a simple and practical manner, in particular with circular line sections. A heating section exactly in the radial center can thus be avoided, which avoids very small bending diameters of the medium lines. The main finding here is that the entire drying section does not have to be formed with the heating section, and therefore by cleverly forming the flow section through a cylindrical and an annular gap-shaped area, a variant can be created in which the radial center of the heating section can be left out.

However, a reverse design can also be advantageous if the heating section is only arranged in the cylindrical interior. For this variant, a design of the heating section can be made possible in which the heating section as a whole only has to be designed for a smaller diameter in the printing chamber, which is smaller than the diameter of the entire printing interior.

• - das Adsorptionsmaterial als granulares Schüttgut ausgebildet ist mit einer maximalen Korngröße von bis zu 12 mm, vorzugsweise bis zu 8 mm, insbesondere bis zu 5 mm und/oder mit einer Korngröße im Bereich von 1 mm bis 12 mm, vorzugsweise 1,5 mm bis 8 mm und insbesondere 2 mm bis 5 mm und
• - der Heizabschnitt so ausgebildet ist, dass das Adsorptionsmaterial die Mediumleitungen umgibt, und insbesondere
  • - die Mediumleitungen Wärmeleitbleche aufweisen und das Adsorptionsmaterial auch zwischen den Leitblechen liegt.

According to one aspect, it is proposed that

• - the adsorption material is designed as a granular bulk material with a maximum grain size of up to 12 mm, preferably up to 8 mm, in particular up to 5 mm and/or with a grain size in the range of 1 mm to 12 mm, preferably 1.5 mm to 8 mm and in particular 2 mm to 5 mm and
• - the heating section is designed such that the adsorption material surrounds the medium lines, and in particular
  • - the medium lines have heat conducting plates and the adsorption material is also located between the conducting plates.

The adsorption dryer and thus also the pressure vessel with the heat exchanger or heating section installed therefore has such granular adsorption material and the heating section and the adsorption material are coordinated with one another in such a way that the adsorption material essentially completely surrounds the heating section. However, the adsorption material is also arranged in areas of the pressure vessel where there is no heating section. The pressure vessel is therefore filled as completely as possible with adsorption material.

In addition or alternatively, it is proposed that a distance between adjacent medium lines and/or between adjacent heat conducting plates corresponds to at least 1.2 times a maximum grain size of the adsorption material, and corresponds to a maximum of five times, preferably a maximum of three times and in particular a maximum of twice the maximum grain size. This makes it possible to ensure that the adsorption material fits well as a bulk material between the lines or heat conducting plates, in particular can be poured between them, and at the same time a good heat input is ensured because excessive distances are avoided.

Two sections of the same medium line can also be understood as adjacent medium lines if, for example, it is arranged in a spiral shape or is arranged in a meandering manner so that such two sections lie next to each other. It was therefore recognized here that good heat transfer from the respective medium line or heat conducting plate to the filled granular adsorption material can be achieved if the geometric design of the heat exchanger or its heating section is such that all elements, including the medium lines and, if present, also the heat conducting plates, are surrounded by the adsorption material from as many sides as possible, as long as they are free.

According to the invention, a compressed gas system for providing dried compressed gas, in particular compressed air, with an adsorption dryer is also proposed, wherein the compressed gas system has a compressor for generating the compressed gas, the compressor is operated using a compressor oil and the heat exchanger is connected to the compressor in order to use the compressor oil or a part thereof as a heat transfer medium.

It was particularly recognized here that a compressor that can be operated in a known manner uses compressor oil that is heated when the compressed gas is compressed, in particular when the air is compressed to form compressed air. Such heated compressor oil must be cooled again in order to prevent the compressor from overheating. Another advantage of cooling the oil is that the efficiency of the compressor and thus of the compression is increased.

For this purpose, the compressor oil can be used as a heat transfer medium for the heat exchanger. There, heat can be transferred from the compressor oil to the adsorption material and the regeneration gas which cools the compressor oil. However, it is also possible that if the heat generated by the compressor in the compressor oil is not sufficient, the compressor oil is additionally heated before it is fed to the heat exchanger.

It was particularly recognized here that the adsorption dryer can be operated particularly efficiently in terms of energy. The heat exchanger is adapted so that the compressor oil is used as a heat transfer medium. In particular, an inner diameter of the medium channel or of the several medium channels in the at least one medium line is selected such that the compressor oil, which can be comparatively viscous, can be passed through the heat exchanger.

• - der Adsorptionstrockner
  • - zum Trocknen eines Druckgases, insbesondere Druckluft, vorgesehen ist, und
  • - wenigstens einen Druckbehälter aufweist mit
    • - einem Adsorptionsmaterial zum Adsorbieren von Feuchtigkeit aus dem Druckgas, das in den Druckbehälter eingefüllt ist,
    • - einem Trocknungseinlass zum Einlassen eines Druckgases zum Trocknen,
    • - einem Trocknungsauslass zum Auslassen des Druckgases nach dem Trocknen und
    • - einer Trocknungsstrecke, die das Druckgas in einem Trocknungsbetrieb vom Trocknungseinlass zum Trocknungsauslass durchströmt, und
  • - wenigstens einen Wärmetauscher aufweist, wobei
    • - von dem wenigstens einen Wärmetauscher jeweils der Heizabschnitt in dem Druckbehälter angeordnet ist und
    • - der Heizabschnitt jeweils von dem Adsorptionsmaterial umgeben ist, wobei das Adsorptionsmaterial als granulares Schüttgut ausgebildet ist. Dazu wird vorgeschlagen, dass
  • - der Adsorptionstrockner gemäß einem der vorstehend beschriebenen Aspekte ausgebildet ist, die auf einen Adsorptionstrockner gerichtet sind, und/oder der Wärmetauscher gemäß einem der vorstehend erläuterten Aspekte ausgebildet ist, die auf einen Wärmetauscher gerichtet sind.

According to the invention, a method for operating a compressed gas system is also proposed, which has an adsorption dryer with at least one heat exchanger, wherein

• - the adsorption dryer
  • - is intended for drying a compressed gas, in particular compressed air, and
  • - has at least one pressure vessel with
    • - an adsorption material for adsorbing moisture from the compressed gas filled into the pressure vessel,
    • - a drying inlet for admitting a compressed gas for drying,
    • - a drying outlet for discharging the compressed gas after drying and
    • - a drying section through which the compressed gas flows in a drying operation from the drying inlet to the drying outlet, and
  • - has at least one heat exchanger, wherein
    • - of the at least one heat exchanger, the heating section is arranged in the pressure vessel and
    • - the heating section is surrounded by the adsorption material, whereby the adsorption material is designed as a granular bulk material. For this purpose, it is proposed that
  • - the adsorption dryer is designed according to one of the aspects described above which are directed to an adsorption dryer, and/or the heat exchanger is designed according to one of the aspects explained above which are directed to a heat exchanger.

• - Betreiben des Druckbehälters in einem Trocknungsbetrieb, in dem das Druckgas durch den Druckbehälter vom Trocknungseinlass zum Trocknungsauslass geleitet wird, um Feuchtigkeit an das Adsorptionsmaterial abzugeben, und
• - Betreiben des Druckbehälters in einem Regenerationsbetrieb, in dem ein Regenerationsgas, insbesondere Druckluft, besonders getrocknete Druckluft, durch die Trocknungsstrecke geleitet wird, insbesondere vom Trocknungsauslass zum Trocknungseinlass, sodass das Regenerationsgas durch das Adsorptionsmaterial strömt und entlang eines Heizabschnitts des Wärmetauschers strömt, um Feuchtigkeit aus dem Adsorptionsmaterial aufzunehmen, wobei
• - der Wärmetauscher im Regenerationsbetrieb mit einem Wärmeträgermedium beheizt wird, um Wärme von dem Wärmeträgermedium an das Regenerationsgas und an das Adsorptionsmaterial abzugeben, wobei insbesondere
• - als Wärmeträgermedium Kompressoröl eines Kompressors des Adsorptionstrockners verwendet wird.

The procedure includes the steps

• - operating the pressure vessel in a drying operation in which the pressurised gas is passed through the pressure vessel from the drying inlet to the drying outlet to release moisture to the adsorption material, and
• - operating the pressure vessel in a regeneration mode in which a regeneration gas, in particular compressed air, in particular dried compressed air, is passed through the drying section, in particular from the drying outlet to the drying inlet, so that the regeneration gas flows through the adsorption material and flows along a heating section of the heat exchanger to absorb moisture from the adsorption material, wherein
• - the heat exchanger is heated with a heat transfer medium in regeneration mode in order to transfer heat from the heat transfer medium to the regeneration gas and to the adsorption material, in particular
• - compressor oil from a compressor of the adsorption dryer is used as the heat transfer medium.

The method is therefore directed to operating a compressed gas system with an adsorption dryer. Such an adsorption dryer has a heat exchanger which is arranged in the pressure vessel. The adsorption dryer and/or the heat exchanger can be designed and operated as described above.

In particular, it is intended that the pressure vessel is operated in a drying mode and in a regeneration mode, namely one after the other. First, the pressure vessel is operated in the drying mode, in which the compressed gas is passed through the pressure vessel for drying. The adsorption material absorbs moisture from the compressed gas. Then, when the adsorption material has absorbed a corresponding amount of moisture, the pressure vessel is operated in the regeneration mode. The moisture is then removed from the adsorption material by the regeneration gas.

In this regeneration mode, the heat exchanger is operated, which is particularly inactive in the drying mode. In the regeneration mode, however, the adsorption material is heated and thus the regeneration gas is also heated directly and indirectly, which means that it can absorb more moisture so that the adsorption material can be dried better.

For this purpose, the heat exchanger is heated in regeneration mode with the heat transfer medium, which is passed through the heat exchanger, in particular through the medium lines.

It is particularly suggested that the heat transfer medium is compressor oil from a compressor that generates compressed gas for the adsorption dryer. A compressed gas system, which can also be referred to synonymously as a compressed gas generation device, with an adsorption dryer can thus be operated in a particularly energy-efficient manner.

In particular, there are at least two pressure vessels in such an adsorption dryer, which are operated alternately, so that essentially one pressure vessel is operated in drying mode, while the other pressure vessel is operated in regeneration mode. These operating modes can then alternate for the two pressure vessels. This means that the compressor oil of the compressor of the adsorption dryer can basically be used constantly to heat a heat exchanger in one of the pressure vessels and thus cool it. For this purpose, it is fed to the heat exchanger whose pressure vessel is operating in regeneration mode.

• 1 und 2 zeigen jeweils einen Adsorptionstrockner in einer funktionalen Darstellung.
• 3 ist eine Veranschaulichung einer Raumausnutzung eines Druckbehälters.
• 4 bis 12 veranschaulichen verschiedene mögliche Ausführungsformen eines Wärmetauschers.
• 13 veranschaulicht eine Bauform eines Druckbehälters mit Ringspalt.
• 14 veranschaulicht eine weitere mögliche Form eines Wärmetauschers.

The invention is explained in more detail below with reference to the accompanying figures.

• 1 and 2 each show an adsorption dryer in a functional representation.
• 3 is an illustration of the space utilization of a pressure vessel.
• 4 to 12 illustrate various possible designs of a heat exchanger.
• 13 illustrates a design of a pressure vessel with an annular gap.
• 14 illustrates another possible form of a heat exchanger.

1 shows a compressed gas system 100 in a schematic representation. The compressed gas system 100 has a compressor 1 and an adsorption dryer 102. The compressor 1, which can also be referred to as a compressor, interacts with an oil cooler 2, an oil separator tank 3 and a compressed air cooler 4, which will be described in more detail below. The compressor supplies compressed air to the adsorption device 102, which is provided between the two valves 5 and 6.

The adsorption dryer 102 has two pressure vessels 7 and 8, which can also be referred to as vessels for simplicity. In particular, these two pressure vessels 7 and 8 operate in alternating mode, so that one operates in drying mode and the other in regeneration mode. For this purpose, the compressed gas for drying in drying mode can be supplied to one of the two vessels 7 and 8 by setting the valves 5 and 6 accordingly.

Each of the two containers 7 and 8 has an upper part 7a or 8a and a lower part 7b or 8b. Both containers are filled with an adsorption material, which is indicated as a granular material.

Both containers 7 and 8 each have a drying inlet 103 and 104, respectively, as well as a drying outlet 105 and 106, respectively. In the embodiment shown, the drying inlets 103 and 104 are arranged at the bottom and the drying outlets 105 and 106 at the top. During drying operation, the compressed air to be dried flows from bottom to top and the regeneration air flows from top to bottom.

The lower part 7b or 8b of the containers 7 or 8 can be heated by means of a heater 16 or 17, which thus each form a heating device. If compressed air flows in from the drying inlet 103 or 104, it first flows through the heating area, although this is switched off in drying mode, and then through the upper part 7a or 8a. In regeneration mode, the regeneration air flows from top to bottom, i.e. flows in at the drying outlet 105 or 106, first flows through the upper part 7a or 8a and then the lower part 7b or 8b, which accommodates or can form the heating area. In regeneration mode, the heater 16 or 17 is in operation.

In drying mode, the dried compressed air flows out either from the drying outlet 105 or the drying outlet 106, depending on which of the two containers 7 and 8 is operating in drying mode, and flows essentially to the valve 12, which can also be referred to as the outlet valve, and from there to the dryer outlet 13, namely to the outlet of the adsorption device 102 as a whole. However, an additional container with adsorption material can also be connected in order to compensate for fluctuations in the degree of humidity of the dried compressed air, which is provided according to one embodiment, but is not shown here for the sake of simplicity.

At the same time, part of the dried compressed air is led through throttles 10 and 11 in front of the valve 12, one or both of which reduce the pressure of the dried compressed air, in particular to approximately ambient pressure. Which of the two throttles Which valve 10 or 11 reduces the pressure or which one carries out a pressure reduction to what extent depends on which of the two containers 7 and 8 is in drying mode and which is in regeneration mode. In any case, via these two throttles 10 and 11, controlled by the valve 9 arranged between them, part of the dried compressed air is transferred from the container that is operating in drying mode to the container that is operating in regeneration mode.

The container operating in regeneration mode thus receives regeneration air at the drying outlet 105 or 106, which flows through the respective container 7 or 8, thereby flowing through the lower part 7b or 8b, which can be regarded as the heating area, and finally flows out at the drying inlet 103 or 104. From there, the regeneration air can be discharged to the environment via the valve 18 or 19 and a downstream silencer 20 or 21.

A possible embodiment is thus shown in simplified form in 1 The air is compressed in the compressor 1. Oil, which has been cooled in the oil cooler 2, is injected into the compressor. The warm compressed air-oil mixture is separated in the oil separator tank 3. The compressed air flows from the oil separator tank through the compressed air cooler 4 and is cooled there.

Likewise, the temperature or a temperature level of the oil can be increased by leading the entire oil, or parts of it, past the oil heat exchanger 2 of the compressor, in the sense of a bypass, and thus feeding it to the compressor block at a higher temperature.

A particularly efficient embodiment that uses the waste heat from the compression process is in 2 The structure corresponds to that in 1 with a concrete embodiment for the heaters 16 and 17.

The heaters 16 and 17 can be supplied with warm oil from the compressor by opening the valves 14 or 15. If neither of the two heaters is active, the valves 14 and 15 are closed and the valve 22 is opened instead.

It was recognized that pressure vessels for compressed air applications are usually designed in a round design, as this allows a relatively thin wall thickness at corresponding operating pressures. This saves, among other things, the cost and weight of the pressure vessels. Since the heat exchanger is positioned within a pressure vessel, it is proposed that the geometry of the heat exchanger has a shape that is compatible with the pressure vessel. In the area for which heating is desired, as few or no areas as possible should remain in which only insufficient heat input is possible, e.g. if elements of the heat exchanger are too far away from there. This would impair the efficiency of the regeneration operation. Consequently, all areas to be heated should be easily reached with the heat exchanger, especially in the direction perpendicular to the flow. Using a cuboid heat exchanger within a round pressure vessel is therefore less suitable, which is due to the 3 is illustrated.

Alternatively, areas into which the heat exchanger cannot sufficiently transfer heat could be blocked, i.e. provided with filler or similar, in order to no longer make them available for filling with dry material, which is what the four grey areas on the side in 3 This would result in additional costs due to the packing elements and, in addition, the size of the pressure vessel would have to be increased as a result of the packing elements in order to continue to be able to use a constant amount of desiccant, which was recognized as unfavorable.

It was recognized that the individual elements of the heat exchanger, especially the medium lines, should be spaced a suitable distance from each other. If this distance is too large, the heat input into the desiccant flowing through it is reduced and the regeneration operation becomes less effective with a constant regeneration air flow. If the distance is too small, there is little space between the elements for the desiccant. In particular, with a desiccant in granulate form, a distance between the heat exchanger elements that is too small is disadvantageous, as filling or emptying the granulate is then made more difficult, or desiccant beads can become jammed and filling or emptying is no longer possible.

Suitable values for the distance between individual elements of the heat exchanger start at approximately slightly more than the simple value of the desiccant diameter, or the maximum granulate diameter in the case of a polydisperse bed. A sensible upper limit for the distance is approximately two to three times the value of the said diameter, i.e. two or three times the maximum grain size. With distance values above this, heat input is still possible, but this will be less pronounced in comparison.

The individual elements of the heat exchanger should have the most suitable geometry, In particular, they must have a large surface area in order to achieve a suitable heat input into the surrounding area, i.e. the area through which the desiccant flows, due to the comparatively moderate temperature of the heated oil.

Ideally, as few elements of the heat exchanger as possible should be designed as a continuous unit in the direction of flow of the regeneration gas, i.e. in the longitudinal direction, especially when using desiccant in granulate form. Such surfaces can be seen as additional walls of the bed area. The gap ratio of the bed increases towards the wall and reaches the value 1 there. This creates a slightly excessive speed near the wall, which is detrimental to the adsorption equilibrium between the gas flowing through, in particular the air flowing through, and the desiccant. As a result, the drying and regeneration properties of the structure deteriorate.

Due to the increased viscosity of oil compared to water, for example, it is important to ensure that the channel dimensions within the heat exchanger are appropriately dimensioned in order to keep the pressure loss of the oil within a suitable range. It is suggested that at least one medium channel be selected with this in mind.

• Es wird ein Wärmetauscher für einen runden Bauraum vorgeschlagen, was sich wie weiter oben beschrieben für den Einsatz innerhalb eines Druckbehälters vorteilhaft auswirkt. Es wird ein Wärmetauscher so ausgeführt, dass ein Befüllen und Entleeren dessen Zwischenräume mit Trockenmittel-Granulat möglich ist, aber auch wiederum ein genügender Wärmeeintrag in diese Trockenmittel-Schüttung möglich ist. Der Wärmetauscher kann aus Microchannel-Profilen bestehen, die gebogen sind, um einen Wärmetauscher für einen runden Bauraum zu bilden. Die Vorteile dieser Profile sind weiter oben beschrieben bzw. ergeben sich aus den erkannten und beschriebenen Nachteilen des Standes der Technik. Ebenso kann der Wärmetauscher als Lamellenwärmetauscher ausgeführt sein. Der hier vorgeschlagene Wärmetauscher spezieller Bauform kann auch als Wärmetauscher spezieller Bauform bezeichnet werden, weil er auch die Bauform des Druckbehälters berücksichtigt, die sich auch auf seine Bauform auswirkt. Er ist auch für die Anwendung in neuartigen Adsorptions-Trocknungsverfahren vorgesehen, wie es weiter oben beschrieben wurde.

Key aspects of the invention are explained below using embodiments and the accompanying figures:

• A heat exchanger for a round installation space is proposed, which, as described above, is advantageous for use within a pressure vessel. A heat exchanger is designed in such a way that the spaces between it can be filled and emptied with desiccant granules, but also that sufficient heat can be introduced into this desiccant filling. The heat exchanger can consist of microchannel profiles that are bent to form a heat exchanger for a round installation space. The advantages of these profiles are described above or result from the recognized and described disadvantages of the prior art. The heat exchanger can also be designed as a plate heat exchanger. The heat exchanger of special design proposed here can also be referred to as a heat exchanger of special design because it also takes into account the design of the pressure vessel, which also affects its design. It is also intended for use in new adsorption drying processes, as described above.

A suitable heat exchanger of special design for use in novel adsorption drying processes is in 4 shown. This heat exchanger 1200 is shown in a perspective view and a top view. It has, for example, 12 medium lines 1202 and thus 12 line levels; there can also be 6 or 18, or more or less. The 12 medium lines 1202 are arranged between a supply channel 1204 and a discharge channel 1206. The heat exchanger 1200 shown combines the advantages of suitable integration into a round pressure vessel with the advantages of microchannel profiles, as described above in relation to the properties and advantages mentioned. By means of a design-specific, individually definable spiral winding distance, which is referred to here as the intermediate distance 1208, the distance between the individual heat exchanger elements, i.e. also between the medium lines, or medium line sections, can be set to an optimum. One round of one of the spiral-shaped medium lines 1202 can be referred to as a medium line section or synonymously as a line section. The intermediate distance 1208 is then a distance between two medium line sections or between two line sections.

The intermediate distance 1208 can be at least 6 mm, preferably at least 9 mm, in particular at least 15 mm and/or allow a filling of the granular adsorption material 1280 with a maximum grain size of up to 12 mm, preferably up to 8 mm, in particular up to 5 mm in the intermediate distance 1208.

The medium lines 1202 are flowed through in parallel here, namely from the supply channel 1204 to the discharge channel 1206. Granular adsorption material 1280 is shown as an example, which is intended to completely surround the heat exchanger in the fully equipped pressure vessel in which the heat exchanger 1200 is to be inserted. It is shown here only for illustration purposes to show that the granular adsorption material is arranged both horizontally and vertically between the medium lines 1202 or the medium line sections 1202 and can therefore surround each medium line 1202.

4 also shows an enlarged section A, in which it is shown schematically that the granular adsorption material 1280 can also be arranged in a vertical direction between the medium lines. The granular adsorption material 1280 can thus also be arranged between Line levels 1203 can be arranged. Section A thus shows two of the line levels 1203 with granular adsorption material 1280 arranged between them.

The medium lines 1202 in 4 essentially have a very flat cross-section and are designed as extruded profiles, which makes this cross-sectional shape possible.

A common manifold for all microchannel profiles as a fluid inlet, i.e. the supply channel 1204, and a common manifold as a fluid outlet, i.e. the discharge channel 1206, enable all medium channels, which can be designed as microchannel channels here and which are designed in the medium lines 1202 or which form the medium lines 1202, to be flowed through in parallel. This has a beneficial effect on the pressure loss compared to a serial flow through all channels, especially when oil is used as the fluid flowing through the channels. In a different design, however, the profiles in the manifolds can also be connected in such a way that a partial or complete serial flow is possible.

The manifolds can be designed as circular tubes, or in any other design, which is exemplified in 5 shown. The 5 shows a top view of a heat exchanger 1300 with a medium line 1302. A discharge channel 1306 is in a 4 provided for in a different form.

6 shows a further heat exchanger 1400 in a top view, with a supply channel 1404 and a discharge channel 1406. In order to further improve the heat input, heat conducting plates 1410 can be provided, which can also be referred to as lamellae or fins, namely between the individual turns of the microchannel profile, i.e. medium lines 1402, which can be connected to the microchannel profile in a heat-conducting manner on one side, but also on both sides, which in 6 is shown. In particular, the heat conducting plates, slats or fins are arranged approximately at right angles to the respective microchannel profiles or medium lines, so that they protrude perpendicularly from them. The connection is preferably materially bonded. As described above, it is important to ensure that there is a suitable distance between two adjacent heat conducting plates 1410 or the slats/fins. The use of slats/fins is shown here as an example, but should also be considered an option for the following versions. 6 shows the heat conducting plates 1410 or the slats/fins only in a partial area for illustrative purposes. However, they are preferably arranged in a larger area, in particular essentially over a complete distance from the supply channel 1404 to the discharge channel 1406, at least over more than 50% of the distance.

The distances between the medium lines or medium line sections of the heat exchanger 1400 may correspond to those for the heat exchanger 1200 of the 4 Accordingly, granular adsorption material 1480 can be arranged between the medium lines or medium line sections. In 6 It is additionally shown that the heat conducting plates 1410 allow the granular adsorption material 1480 to fit between them as well. The granular adsorption material 1480 and the heat conducting plates 1410 are in 6 only shown as an example for a small area, but they are basically intended for the entire heat exchanger 1400 or the entire heating area in which the heat exchanger 1400 is to be arranged.

The profiles can be connected to the manifolds before or after the profiles are formed; for example, the material-locking joining process of soldering can be used for this purpose.

Another design is such that the manifolds are positioned outside the heat exchanger, which 7 shows. 7 thus shows a heat exchanger 1500 in a perspective view and a top view, with medium lines 1502 between a supply channel 1504 and a discharge channel 1506, which are designed here as collecting pipes.

Another version is in 8 shown and designed in such a way that concentric circular rings of microchannel profiles are used, which form the medium lines 1602, whose collecting pipes are interconnected with U-tubes, as 8 shows. Collector pipe front sides that are not connected to each other are closed. 8 thus shows a heat exchanger 1600 in a perspective view and a top view, with medium lines 1602 between a supply channel 1604 and a discharge channel 1606 with further collecting lines 1612, which are designed here as collecting pipes.

Another embodiment is designed in such a way that concentric circular rings made of microchannel profiles are used to form the medium lines 1702, the manifolds of which consist, for example, of extruded double pipes, see 9 This allows a compact design and positioning of the manifolds in a common area. 9 thus shows a heat exchanger 1700 in a perspective view and a top view, with medium lines 1702 between a supply channel 1704 and a discharge channel 1706, with further collecting lines 1712, which are designed here as collecting pipes. An intermediate distance 1708 between the medium lines 1702 is also shown.

Another design of a heat exchanger of special construction can be a meander shape, see 10 When designing, attention must be paid to the minimum bending radius of the profile. 10 thus shows a heat exchanger 1800 in a perspective view and a top view, with medium lines 1802 between a supply channel 1804 and a discharge channel 1806, which are designed here as collecting pipes.

Another version of a heat exchanger of special design for use in new adsorption drying processes and the heat exchange there to the drying agent flowing through can be designed as a plate heat exchanger and is in 11 Due to its corresponding design, this heat exchanger 1900 can be used for round installation space cross-sections, whereby the desiccant is located between the respective heat conducting plates 1910, which are designed here as fins. 11 thus shows a heat exchanger 1900 in a perspective view and a top view, with medium lines 1902 with heat conducting plates 1910. In this embodiment, by way of example, six medium lines 1902 with heat conducting plates 1910 are arranged between a supply channel 1904 and a discharge channel 1906, which are designed here as collecting pipes. There are therefore two supply channels 1904 and two discharge channels 1906.

A heat exchanger of special design for use in new adsorption drying processes, which is suitable for an annular installation space, is based on the heat exchanger 1200 according to 4 in 12 However, the principle also applies to other heat exchanger designs. 12 thus shows a heat exchanger 2000 in a perspective view and a top view, with medium lines 2002 between a supply channel 2004 and a discharge channel 2006, which are designed here as collecting pipes.

A heat exchanger designed in this way can be used, for example, for pressure vessels that are ring-shaped or whose interior is blocked or divided by a round partition wall that may be coaxial to the vessel axis, as in 13 is shown. 13 thus shows a pressure vessel 2120 with a cylindrical interior 2122 and an annular gap space 2124, which are separated from one another by a coaxial partition wall 2126. In drying operation, a pressurized gas can flow into the annular gap 2124 according to inflow arrow 2131, flow over from the annular gap 2124 into the cylindrical interior 2122 according to bypass arrow 2132 and flow out of the pressure vessel 2120 according to outflow arrow 2133.

The coaxial partition wall 2126 is connected to the container 2120 in the lower area and forces a flow through the container, first in one area and then in the separated area. Both areas are connected to each other in the upper part of the pressure vessel, but a container can also be designed so that the connection of the two areas takes place in the lower part of the container. The arrows show the flow direction during adsorption, i.e. in drying mode, as an example for the structure shown. Regeneration takes place in the opposite flow direction. The ring-shaped heat exchanger 2100 of special design is used in the 13 indicated by a dashed line.

For use in new adsorption drying processes and the heat exchange there to the drying agent flowing through, an annular finned heat exchanger can also be used for such a construction space, which is in the 14 The desiccant is then located between the respective slats. As described above, it is important to ensure that there is an appropriate distance between two adjacent slats.

14 thus shows a heat exchanger 2200 in a perspective view and a top view, with medium lines 2202 with heat conducting plates 2210. According to this embodiment, 24 medium lines 2202 are provided, of which two medium lines 2202 are guided in parallel through a row of heat conducting plates 2210. In a right-hand view in the 14 The enlargement shown schematically shows such a pair of two medium lines 2202 with several heat conducting plates 2210. Furthermore, 14 a supply channel 2204 and a discharge channel 2206, which are designed here as collecting pipes.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 4898599 [0009]

Claims (17)

Heat exchanger for arrangement in a pressure vessel having a granular adsorption material of an adsorption dryer intended for drying a compressed gas, in particular compressed air, and for transferring heat from a heat transfer medium, in particular oil, to the granular adsorption material, with - a heating section for transferring heat from the heat transfer medium to the adsorption material, and the heating section comprises - a plurality of medium lines (1202, 1402), each having at least one medium channel, for guiding the heat transfer medium in the medium line, wherein - the heating section has a substantially cylindrical shape with a longitudinal axis, - the medium lines are arranged in a plurality of line levels in the direction of the longitudinal axis, - the medium lines are designed and connected to one another in such a way that the heat transfer medium can flow through them together in parallel and/or in series, - adjacent line levels and/or medium lines of adjacent line levels are spaced apart from one another in the direction of the longitudinal axis and - the medium lines are designed as extruded profiles. Heat exchanger for arrangement in a pressure vessel having a granular adsorption material of an adsorption dryer intended for drying a compressed gas, in particular compressed air, and for transferring heat from a heat transfer medium, in particular oil, to the granular adsorption material, with - a heating section for transferring heat from the heat transfer medium to the adsorption material, and the heating section comprises - several medium lines, each having at least one medium channel, for guiding the heat transfer medium in the at least one medium channel, wherein - the heating section has a substantially cylindrical shape with a longitudinal axis, - the medium lines are arranged in several line levels in the direction of the longitudinal axis, - the medium lines are designed and connected to one another in such a way that the heat transfer medium can flow through them together in parallel and/or in series, - the medium lines are provided with heat conducting plates, and - the heat conducting plates are spaced apart from one another such that a bed of granular adsorption material with a maximum grain size of up to 12 mm, preferably up to 8 mm, in particular up to 5 mm is possible and/or - adjacent heat conducting plates of the same medium line are spaced apart by at least 6 mm, preferably at least 9 mm, in particular at least 15 mm. Heat exchanger according to one of the preceding claims, characterized in that - in each case in one of the line levels - exactly one at least partially circumferential line section of a medium line is provided, or - at least two line sections of a medium line are arranged parallel to one another, with an intermediate distance between the line sections which is at least 6 mm, preferably at least 9 mm, in particular at least 15 mm and/or which allows a filling of granular adsorption material with a maximum grain size of up to 12 mm, preferably up to 8 mm, in particular up to 5 mm in the intermediate distance and wherein - the heating section in each case in one of the line levels - has a circular shape, and/or - a circular outer contour, and/or - at least in sections a spiral shape. Heat exchanger according to one of the preceding claims, characterized in that - the heating section for arrangement in a pressure vessel with a circular-cylindrical or annular gap-shaped interior has a curved outer contour adapted to the interior in each case in one of the line levels. Heat exchanger according to one of the preceding claims, characterized in that - the at least one medium channel has an average diameter, - the medium line to the medium channel has a wall thickness and - a ratio between the average diameter of the medium channel and the wall thickness is in the range from 2 to 50, in particular 5 to 25, and/or - the wall thickness has a thickness of 0.15 mm to 2 mm, in particular 0.15 mm to 1.5 mm. Heat exchanger according to one of the preceding claims, characterized in that - the medium lines each have an elongated cross-section which has a longitudinal dimension in the direction of the longitudinal axis of the heating section and a transverse dimension transversely thereto, wherein the longitudinal dimension is at least 1.5 times, in particular at least twice as large as the transverse dimension, and/or - the medium lines each have at least two medium channels running parallel to one another. and at least two of the parallel medium channels are aligned and spaced apart from one another in the direction of the longitudinal axis. Heat exchanger according to one of the preceding claims, characterized in that - the medium lines are designed as extruded profiles, in particular made of aluminum or an aluminum alloy. Heat exchanger according to one of the preceding claims, characterized in that - the heating section - has a plurality of collecting lines, comprising at least - one supply channel for supplying the heat transfer medium and - one discharge channel for discharging the heat transfer medium, wherein - the supply channel and the discharge channel and optionally further collecting lines are each arranged parallel to the longitudinal axis and - the medium lines are each arranged between the supply channel and the discharge channel, so that the heat transfer medium flows parallel through the medium lines from the supply channel to the discharge channel. Heat exchanger according to one of the preceding claims, characterized in that - two medium lines adjacent to one another in the direction of the longitudinal axis are spaced apart from one another by a longitudinal distance which designates a free distance between them, wherein - the longitudinal distance corresponds to at least a minimum thickness of the medium line, in particular at least twice the minimum thickness of the medium line, and in particular the longitudinal distance is a maximum of five times the value of the minimum thickness of the medium line. Heat exchanger according to one of the preceding claims, characterized in that - adjacent medium lines or adjacent medium line sections of the same line level are connected by heat conducting plates and/or - several medium lines or several medium line sections are guided parallel to one another transversely through several heat conducting plates by which they are connected, or - if the medium lines are designed as extruded profiles, the extruded profiles do not have any heat conducting plates protruding from the extruded profile. Adsorption dryer for drying a compressed gas, in particular compressed air, with - at least one pressure vessel with - an adsorption material for adsorbing moisture from the compressed gas that is filled into the pressure vessel, - a drying inlet for letting in a compressed gas for drying, - a drying outlet for letting out the compressed gas after drying and - a drying section through which the compressed gas flows in a drying operation from the drying inlet to the drying outlet, and - at least one heat exchanger according to one of the preceding claims, wherein - of the at least one heat exchanger, the heating section is arranged in the pressure vessel and - the heating section is surrounded by the adsorption material, wherein the adsorption material is designed as a granular bulk material. Adsorption dryer according to claim 11 , characterized in that - the drying section - has a first region facing the drying inlet and - a second region facing the drying outlet, and - the heating section is arranged in the first region and in particular the heating section is not provided in the second region. Adsorption dryer according to claim 11 or 12 , characterized in that - a switching device is provided for switching between the drying operation and a regeneration operation, wherein in the regeneration operation - a regeneration gas flows through the pressure vessel and the drying section from the drying outlet to the drying inlet in order to remove moisture from the adsorption material, and - the first region is heated, while - the second region is not heated or is heated to a lesser extent. Adsorption dryer according to one of the Claims 11 until 13 , characterized in that - the pressure vessel has an annular gap space and a cylindrical interior space surrounded by the annular gap space, wherein the annular gap space and the cylindrical interior space are connected to one another in such a way that - the compressed gas for drying can flow from the drying inlet via the annular gap space and further via the cylindrical interior space to the drying outlet, and the heating section of the heat exchanger is arranged in the annular gap space, or - the compressed gas for drying can flow from the drying inlet via the cylindrical interior space and further via the annular gap space to the drying outlet, and the heating section of the heat exchanger is arranged in the cylindrical interior space. Adsorption dryer according to one of the Claims 11 until 14 , characterized in that - the adsorption material is designed as granular bulk material with a maximum grain size of up to 12 mm, preferably up to 8 mm, in particular up to 5 mm and/or with a grain size in the range of 1 mm to 12 mm, preferably 1.5 mm to 8 mm and in particular 2 mm to 5 mm and - the heating section is designed such that the adsorption material surrounds the medium lines, and in particular - the medium lines have heat conducting plates and the adsorption material also lies between the guide plates, and/or - a distance between adjacent medium lines and/or between adjacent heat conducting plates corresponds to at least 1.2 times a maximum grain size of the adsorption material, and corresponds to a maximum of five times, preferably a maximum of three times and in particular a maximum of twice the maximum grain size. Compressed gas system for providing dried compressed gas, in particular compressed air, with an adsorption dryer according to one of the Claims 11 until 15 , characterized in that - the compressed gas system has a compressor for generating the compressed gas, - the compressor is operated using a compressor oil, and - the heat exchanger is connected to the compressor in order to use the compressor oil or a part thereof as a heat transfer medium. Method for operating a compressed gas system which has an adsorption dryer with at least one heat exchanger, wherein - the adsorption dryer - is provided for drying a compressed gas, in particular compressed air, and - has at least one pressure vessel with - an adsorption material for adsorbing moisture from the compressed gas which is filled into the pressure vessel, - a drying inlet for admitting a compressed gas for drying, - a drying outlet for discharging the compressed gas after drying and - a drying section through which the compressed gas flows in a drying operation from the drying inlet to the drying outlet, and - has at least one heat exchanger, wherein - of the at least one heat exchanger, the heating section is arranged in the pressure vessel and - the heating section is surrounded by the adsorption material, wherein the adsorption material is designed as a granular bulk material, and wherein - the compressed gas system according to claim 16 is designed, the adsorption dryer according to one of the Claims 11 until 15 and/or the heat exchanger according to one of the Claims 1 until 10 is designed, and - the method comprises the steps of - operating the pressure vessel in a drying operation in which the compressed gas is passed through the pressure vessel from the drying inlet to the drying outlet in order to release moisture to the adsorption material, and - operating the pressure vessel in a regeneration operation in which a regeneration gas, in particular compressed air, in particular dried compressed air, is passed through the drying section, in particular from the drying outlet to the drying inlet, so that the regeneration gas flows through the adsorption material and flows along a heating section of the heat exchanger in order to absorb moisture from the adsorption material, wherein - the heat exchanger is heated with a heat transfer medium in the regeneration operation in order to release heat from the heat transfer medium to the regeneration gas and to the adsorption material, wherein in particular - compressor oil from a compressor of the adsorption dryer is used as the heat transfer medium.

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