DE102006058255A1 - Apparatus and method for the thermal treatment of bulk materials - Google Patents

Abstract

The invention relates to a device and a method for the thermal treatment of a bulk material. The device has a treatment chamber (12) for receiving the bulk material; at least one bulk material filling opening (13), at least one bulk material discharge opening (14), at least one treatment gas supply device (15) in the bottom region (16) of the treatment chamber (12); at least one treatment gas removal device (17) in the ceiling region (18) of the treatment chamber (12); and a multiplicity of stowage element layers (19a-n) arranged one above the other in the treatment space (12), wherein a plurality of treatment layers (21a-n) are located between the stowage element layers and the stowage element layers have a passage area between 40% and 98%. According to the invention, at least one baffle element layer (19) extends substantially over the entire cross section of the treatment space (12), and at least one of the treatment layers (21) has a height of less than 100 mm, and / or at least one baffle element layer (19) is provided by means of a separable connection arranged in the treatment room (12). According to the invention, in the method for thermal treatment, the flow velocity of the process gas in at least one baffle element layer (19) lies above the loosening point of the bulk material material.

Description

Various methods for thermal treatment, in particular heating or cooling, but also crystallization of bulk materials under the action of a treatment gas are known in the art. In this case, the throughput of bulk material in comparison to the amount of treatment gas and the gas velocity with which the bulk material flows through play a crucial role. Thus, for example, in a continuous-flow fixed-bed reactor, the gas quantity can be chosen such that a complete heat exchange takes place between the bulk material material and the treatment gas. For this purpose, the gas velocity must be chosen so that it lies below the loosening point of the bulk material and thus prevents back mixing in the fixed bed reactor. With the resulting, low heat transfer coefficient, the residence time to ensure heat exchange in the reactor, but very high. It is known to use stowage elements in fixed bed reactors in order to reduce product pressure and to generate a relative movement between the granules. This is for example in DE 27 23 549 , Gey, or in US 6010667 , Meyer. The low gas velocity, the slow heat transfer and the long residence time remain.

In contrast, can in a fluidized bed or bubbling bed reactor, a high gas velocity be used, resulting in a high heat transfer coefficient and thus shorter Residence times leads. Of the Disadvantage is however, that an average bed temperature forms to the bulk material and equalize the treatment gas, and thus a complete heat exchange not possible is. Somewhat better is the situation if a fluidized bed or bubble bed reactor is divided into several consecutive area, which a good approximation of the bulk material outlet temperature can reach the gas inlet temperature. The disadvantage, however, remains that the treatment gas from the different areas different Has outlet temperatures and thus only partially to the Bulk material inlet temperature equalizes. Equally disadvantageous is the total amount of treatment gas compared to the throughput of bulk material.

The disadvantages described above are achieved in the prior art by arranging a plurality of fluidized bed or bubble bed reactors or reactor areas, in particular one above the other, so that the treatment gas flows through all the reactor areas in countercurrent to the bulk material. (R. Perry, Chemical Engineers Handbook, Fifth Edition, 20 - 87 ; McGraw-Hill). For this purpose, separating trays are necessary which prevent the product passage down, but allow the treatment gas passage upwards. At the same time, the reactor areas are connected to each other via product passages. A disadvantage of this arrangement, the complex and expensive construction of the apparatus, the unused amount of treatment gas flowing through the product passages instead of the trays from one reactor area in the next, or the necessary locking devices to prevent this, as well as the risk that the openings for the treatment gas passage, especially with dust from the bulk material clogged.

In contrast, is It is an object of the present invention, a method and a Device available to ask, whereby the above-mentioned disadvantages are avoided can and that allow a bulk material in a gas stream with a minimal amount of treatment gas in a short time to warm or to cool.

It Another object of the present invention is a method and a device available to provide, which allows the most complete temperature compensation between bulk material and Treatment gas to achieve in a short time.

These Tasks are achieved by the device according to claim 1 and by the Process according to claim 25 solved.

According to the invention a method for treating a bulk material in a device for disposal provided, the device, the at least one treatment room, a filling opening and a discharge for the Bulk material as well a feeder and a route guide for a Treatment gas having a plurality of stacked stowage element layers is provided, and the baffle layers of both the treatment gas, as are also flowed through by the bulk material can.

According to the invention, a device for treating a bulk material, which has at least one treatment space, a filling opening and a discharge opening for the bulk material and a feed device and a discharge device for a treatment gas, with a plurality of match provided on other arranged stowage element layers, wherein the stowage element layers leave a passage area of between 40% and 98% open and / or allow cleaning of the device in an emergency.

Of the Treatment room of the device is surrounded by a housing. The horizontal cross section of the treatment room can be any Having shape, but is preferably round or rectangular. The treatment room is arranged substantially vertically, so that the bulk material the device either from top to bottom or from bottom to bottom flow through at the top. It is important that a uniform product flow can be achieved. The treatment room is laterally by a coat limited. The jacket wall can be cylindrical, conical or a combination of conical and cylindrical segments exist, whereby the gas velocity distribution over the height of the device can be influenced. A widening in the ceiling area allows a reduction of the gas velocity, what the discharge of bulk material prevented.

A Narrowing in the ceiling area allows an increase in the gas velocity, what a stronger one Turbulence leads, which causes any Prevent gluing.

A special design at least approximately rotationally symmetrical housing jacket before, what manufacturing advantages, as well as advantages for one regular Product flow results.

in the Inside the treatment room, a displacement body can be arranged, which is not from the bulk material is flowed through and thus reduces the treatment room. Such Displacer can for Example for implementation of treatment gas, to adjust the free cross-sectional area or to improve the flow of bulk material be used.

A Device can be divided by the use of partitions into several chambers be, with a product distribution on several chambers simultaneously or a product guide from one chamber to the next is conceivable. At least one chamber forms a treatment room with the characterizing features of the present invention.

At least a filling opening opens into the treatment room, allowing to be treated bulk material in the treatment room introduced can be. At the filling opening can for example, it is an opening in the case or the exit from a pipe which is guided into the housing, act. The filling opening can be divided into several segments, resulting in a distribution of the bulk material allowed in the treatment room. Usually is the filling hole in the Ceiling area of the treatment room.

At least a discharge opening ends in the treatment room, so that treated bulk material from the treatment room can be discharged. At the discharge opening it can be, for example around an opening in the case or to enter a pipe that comes out of the case to be led, act. Conveniently, is the discharge opening in the floor area of the treatment room, wherein the bulk material is preferably supplied through a conical region of the discharge opening. The angle of the outlet cone is to the horizontal preferably 50-80 ° when the bulk material in the discharge cone is not fluidized or vibrated, and 15-60 °, in particular 30-50 °, if that bulk material is fluidized or vibrated in the discharge cone.

alternative can be the bulk material also by means of a mechanical discharge device, such as a snail, the discharge opening supplied become. Below the discharge opening can a blocking element, such as a rotary valve, a horizontally arranged discharge roller or an automatic Sliders are located, with the help of the bulk flow from the treatment room is regulated. As a controlled variable can, for example, the filling level of the bulk material in the treatment room or the weight of the bulk material in the device serve.

in the Floor area of the treatment room is at least one Supply device for a treatment gas. The supply device has at least one inlet opening, flows through the treatment gas into the treatment room.

The treatment gas supply means may comprise devices such as downwardly open cones or rows of roofs, as well as conduits or plates with exit bores, as long as a sufficiently even distribution of the treatment gas takes place. A particular embodiment provides that the treatment space is bounded at the bottom by an at least partially gas-permeable shut-off device, in particular a perforated plate with a plurality of inlet openings, at least of process gas In places, but can not be flowed through by the bulk material. For this purpose, the openings are smaller than the diameter of the bulk material particles. The passage area preferably has between 1% and 30%. Preferably, openings between 20 and 90%, in particular between 30 and 80% of the diameter of the bulk material particles. The number and size of the openings can be uniform or uneven. The shut-off device is arranged conically or horizontally.

Below the shut-off device can be a distribution chamber, through the treatment gas is led to the shut-off device. In this distribution room ends at least one feed opening for treatment gas. Furthermore you can Devices for distribution of the process gas, such as baffles, valves or Flaps, as well as separate channels be arranged for individual process gas supply.

alternative the treatment room can down through a non-gas-permeable shut-off device be limited. In this case, the at least one Supply device for a treatment gas to an opening in the case, around the outlet from a pipe or several pipes, in the Housing be led or around a single roof or row of roofs, either with holes provided or open at the bottom act. In this case, a possible displacer for Gas supply can be used.

Conveniently, is the feeder for the treatment gas is directly or indirectly connected to pipelines or channels, by connecting to facilities for pretreatment of Process gas, such as compaction equipment (e.g. Fans, blowers or compressors), heat exchangers or cleaning equipment (eg filters, cyclones or catalytic Combustion equipment) is produced.

A special design According to the present invention, in addition to the at least one supply device for treatment gas in the bottom region of the treatment space at least one further supply device for treatment gas enters the treatment room, resulting in a multi-level heat input or heat transfer, and achieve a multi-stage gas velocity profile.

in the Ceiling area of the treatment room is at least one removal device for the treatment gas. At the route guide For example, it may be an opening in or around the case the entry into a pipe which is led out of the housing, act. The route guide may be located in the mantle or the ceiling of the treatment room.

In or below the routing device can there are devices that allow the passage of process gas, the passage of bulk material but hinder. This can be done for example by a curved or flow channel or with the help of distracting internals, such as a zig-zag separator, done. Usually is the route guide for the Treatment gas directly or indirectly connected to pipelines or ducts, by connecting to facilities for post-treatment of Process gas, such as compaction equipment (e.g. Fans, blowers or compressors), heat exchangers or cleaning equipment (eg filters, cyclones or catalytic Combustion equipment). Between the route guide and feeding device for the treatment gas may be closed or partially closed Circulation exist.

According to the invention in the treatment room a plurality of stowage element layers, wherein the stowage element layers are, for example, nets, Grid or grates or a combination thereof. alternative For example, a stowage element layer can also be made up of a large number of individual ones Constructed of bluff bodies be. The baffle layers are designed to be both of treatment gas as well as bulk material flows through can be. This is a high passage area needed. The passage area results from the cross section through the treatment room at the height a stowage element layer, wherein the passage area equal to that of the bulk material perfused area divided by the free cross-sectional area of the treatment room corresponds. any Displacer in the Treatment room belong not to the free cross-sectional area of the treatment room. According to the invention is the Passage area 40% to 98%. Preferred is the passage area between 50% and 90%, in particular between 60% and 80%.

In order to ensure the bulk material flow, the stowage element layers should have a passage width which is 4 to 40 times greater than the average bulk particle diameter. The passage width is the distance between two storage elements of a storage element layer. If the distance on one axis is less than on the other, the smaller distance is referred to as the passage width. If the bulk material is granules with an average diameter of 0.4 mm to 5 mm, the stowage element layers should have a passage width of 4 mm to 50 mm.

These it is the bulk material to a powder with a mean diameter of less than 0.4 mm, the stowage element layers should have a passage width of 1 mm to 20 mm. Is it the bulk material around chips or flakes with a maximum length of 10 mm to 40 mm, so the stowage element layers should have a passage width of 20 mm up to 200 mm.

Conveniently, are in the treatment room between 3 and 100 stowage element layers preferably more than 5, in particular more are arranged as 10, stowage element layers in the treatment room. More than 100 stowage element layers are conceivable, but lead to a very high height the device, resulting in many cases not wanted is.

The Stauelementschichten should be arranged so that the bulk material treatment preferably evenly he follows. This should usually at least one stowage element layer substantially horizontally in the treatment room be arranged, wherein preferably at least 5 Stauelementschichten are arranged substantially horizontally in the treatment room.

Conveniently, should at least one baffle layer substantially over the entire free cross-sectional area extend the treatment room, preferably at least 5 stowage element layers substantially over the entire free cross-sectional area of the Treatment room should extend. Small open spaces can be used for Example at the edges the stowage element layers or their segments may be present. The open areas but should not exceed 10% of the free cross-sectional area of the treatment room include.

in the Essentially, the stowage element layers are arranged one above the other.

Between the baffle element layers are a plurality of treatment layers.

At least a treatment layer has a height of 10-300 mm. Conveniently, At least 5 treatment layers have a height of 10-300 mm. preferably, the Behandlungsschichen have a height of more than 20 mm, in particular more than 30 mm. Preferably, the treatment layers a height less than 200 mm, in particular less than 100 mm.

In the treatment layers can internals for heat supply or removal, but do not form a complete baffle layer.

The Stauelementschichten can directly with the housing shell be connected or over a separate support structure be arranged in the treatment room.

A Separable connection between the Stauelementschichten and the housing shell or the support structure is preferred.

Even though this through the stowage element layers in the normal operating state is prevented, consists in the thermal treatment of bulk materials with elevated Adhesive tendency in the case of a misoperation, the danger of getting into the Treatment layers form agglomerates that form the baffle element layers can no longer flow through. In order to ensure a cleaning of the device in this situation, can in the device openings be provided, removed by the possible agglomerates can or can destroyed can be. According to the invention should to the height a treatment layer are kept low, that is under 100mm, which limits the size of any agglomerates is or the stowage element layers are intended by means of a separable Connection can be arranged in the treatment room, creating a distance individual stowage element layers and treatment layers or a Package of stowage element layers and treatment layers is made possible.

When separable connection are doing for example by connections Screws, clamps or hang up, which contrary to solid welds or production in one piece.

in the casing the device can more openings be provided, such as sight glasses, cleaning holes, access openings or openings for sensors. Farther is advantageous if the device in the ceiling area for Example opened by a flange and / or when the Open device in the bottom area, for example by a flange connection.

A Stauelementschicht consists of a plurality of individual storage elements. The individual storage elements can be sheets, rods, wires, tubes or individual bluff bodies or a combination of these. The individual storage elements should be arranged so that a deposit of bulk material is avoided, in particular sheets should be substantially edgewise or only lightly (max 30 °) be used angled.

The individual storage elements should be constructed so that they withstand the load of the moving bulk material, but at the same time do not cause large dead zones. Cross-sectional areas of 0.03 to 20 cm ² , in particular 0.07 to 1 cm ² , are preferred. However, any support structures may have larger cross-sectional areas. A preferred embodiment provides that at least one storage element layer consists of a grid, in particular fabric of individual, crossing wires. To have sufficient strength, the individual wires should have a thickness of 2.5 to 10 mm, with wire thicknesses of greater than or equal to 3 mm are preferred. A further preferred embodiment provides that at least one baffle element layer of individual rods or wires, which are arranged in a star shape or parallel to each other, is constructed. A further preferred embodiment provides that at least one storage element layer of individual tubes is constructed as a grate. In this case, there is also the possibility that the pipes are traversed by a heat transfer medium, which can enter or discharge heat in the treatment room. A further preferred embodiment provides that at least one stowage element layer consists of individual bluff bodies, wherein the bluff bodies can be connected to one another horizontally or can be connected vertically to bluff bodies of other stowage element layers. The individual bluff bodies are preferably conical upwards.

Separate Damping elements can be grouped into sections or segments, with In some sections or segments, assemble a stowage element layer leaves.

Point the baffles on a direction or orientation, so can individual Layers offset from one another and / or arranged twisted.

The Device or parts of the device, in particular one or more Stauelementschichten, can be connected to a vibration sensor, the device or Parts of it vibrated.

According to the invention, the treatment gas flows through the treatment room essentially from the bottom up. The flow velocity of the process gas should be in at least one Stauelementschicht above the Loosening point of the bulk material lie. Usually is the flow velocity of the Process gas in at least 5 Stauelementschichten over the Loosening point of the bulk material.

preferably, should the flow rate of the process gas in the stowage element layers between 10% and 150%, in particular between 20% and 75% above the loosening point of the bulk material lie.

According to one execution The present invention is the flow rate of the process gas in at least one treatment layer above the loosening point of the Bulk material.

Conveniently, lies the flow velocity the process gas in at least 5 treatment layers above the Loosening point of the bulk material.

preferably, should thereby the flow velocity of the process gas in the treatment layers between 1% and 100%, in particular between 2% and 50% above the loosening point of the bulk material lie.

A special design provides that the flow rate the process gas in at least 5 treatment layers below the loosening point of the bulk material but in 5 adjacent stowage layers above it Loosening point of the bulk material lies.

The relaxation point is the flow velocity at which the bed is in its lowest state. The determination of the loosening point from a measurement of a pressure loss curve is shown in the VDI Heat Atlas 5th Edition 1988, in Chapter Lf, Figure 4. An approximate calculation can be taken from "Heat and mass transfer in fluidized bed; H. Martin; Chem. Ing. Tech 52 (1980) No. 3, p199-209". For the porosity (P), a calculation is made from the particle geometry turns, where for
P = (1/14 / Os) ^ (1/3) and
Os = surface of the sphere of the same volume / particle surface applies.

For not spherical bulk particles The diameter of the volume equal ball can be used.

alternative let yourself the porosity also from the bulk density at the relaxation point and the product density calculated as P = 1 bulk density / product density.

To step strong deviations of the porosity values after the two types of calculation, so must definitely one Measurement performed become.

These it is the bulk material to granules, in particular with a mean diameter of 1.4 up to 5 mm and a temperature between 0 ° C and 300 ° C, so will the relaxation point achieved at a gas velocity of about 0.6 to 2 m / s.

Of the mean diameter corresponds to the average diameter the volume equal balls of granules.

Prefers are gas velocities in the range of 0.5-4 m / s, in particular greater than 0.7 m / s and / or in particular less than 2 m / s.

The Gas velocity corresponds to the empty tube velocity, So the amount of gas per time divided by the cross section of the treatment room.

By the heat exchange between bulk particles and treatment gas may be the temperature of the treatment gas and thus its flow velocity change from bottom to top in the treatment room. To this change either the coat around the treatment room can at least balance be formed conical in places or arranged displacement body in the treatment room be that the cross-sectional area of the treatment room in proportion to the flow velocity out.

One adequate compensation is achieved when the flow velocity the process gas in at least one treatment layer in the lower Area of the treatment room has a value VU and the flow velocity the process gas in at least one treatment layer in the upper Area of the treatment room has a value VO, where vzw. the relation VU / (VU + VO) = 0.33 to 0.67, in particular, VU / (VU + VO) = 0.39 to 0.61, fulfilled is.

A special design of the inventive Method provides that the bulk material the treatment room flows through from top to bottom. Is doing a hot bulk material cooled, so heated the treatment gas from bottom to top. To the resulting Increase in flow velocity of the treatment gas to compensate, the cross-sectional area in the Upper treatment layers larger be, as in the lower treatment layers. Conversely, that cools Treatment gas in a process for heating a bulk material from bottom to top. Order the resulting decrease in flow rate of the treatment gas can compensate for the cross-sectional area in the upper treatment layers are smaller than in the lower treatment layers. One more way, the upward decreasing flow velocity of the treatment gas to compensate or even a higher speed can be achieved in the upper treatment layers, can be by a strong reduction of the cross-sectional area or by an additional Supply device for Treatment gas to achieve what, especially in the crystallization amorphous granules is advantageous, as a bonding of the Granules can be prevented.

A special design Provides that the flow speed the process gas in at least one treatment layer in the bottom area of the treatment room is between 0.7 m / s and 2 m / s and the flow rate the process gas in at least one treatment layer in the upper Area of the treatment room between 1.5 and 4 m / s empty tube speed is. With this version let yourself in the upper area of the treatment room achieve a stronger backmixing, which is before in particular for the treatment of crystallizable bulk materials and in particular their Crystallization is advantageous.

According to one another preferred embodiment the treatment of the bulk material takes place such that one possible good approximation of the bulk material temperature to the inlet temperature of the treatment gas and the treatment gas temperature takes place at the inlet temperature of the bulk material.

Especially the thermal treatment is preferably such that the treatment gas has an inlet temperature TiG and an outlet temperature TaG has that bulk material has an inlet temperature TiP and an outlet temperature TaP and that TaP is substantially similar to TiG and that TaG essentially adapts to TiP, which is due to the temperature equalization (TiP + TaP - TiG - TaG) / (TiP - TiG) smaller can be calculated as 0.5, in particular smaller than 0.4. at optimal process control can even values below 0.3 can be achieved. Such a good heat exchange let yourself with conventional Fluidized bed or fluidized bed reactors do not reach, but requires a fixed bed reactor. Due to the rapid temperature exchange in the inventive Device, but it is possible a bulk material with much shorter ones Treat treatment times thermally as in a fixed bed reactor. Treatment times in the device according to the invention are customary less than 1 hour, in particular less than 30 minutes. Preference is given to treatment times between 1 and 25 minutes. At treatment time is the time in which the bulk material without or only with low treatment gas flow in the Outlet area, for example, an outlet cone, is not considered.

A another special version The present invention provides that it is the bulk material to particles, in particular granules, one or more polymers is. The polymers may be a virgin material or to trade a recyclate. The polymers may contain other substances than Contain additives.

Especially preferred are polycondensates, such as, for example, polyamide, polyester, Polycarbonate, polylactide, polyhydroxyalkanoates or their copolymers, in particular polyethylene terephthalate or one of its copolymers, wherein mixtures of different polycondensates are used can.

Around the filling level of the bulk material in the inventive Device even with changing Gas velocity and thus also changing bulk density of the bulk material Keeping substantially constant, the device may open a load cell or a probe can be used to measure the level become.

through the filling level, the Treatment time and the distance of the Stauelementschichten can be calculate an average residence time in a treatment layer. To be even heat exchange between the product and the treatment gas to ensure the residence time in a treatment layer between 0.05 and 10 minutes. Preferred times are over 0.1 minutes, especially over 0.2 and less than 5 minutes, especially less than 3 minutes.

A special design provides that at least one filling opening for the bulk material in the lower Part of the treatment room opens. As a result, the bulk material flows from the bottom up through the treatment room, resulting in a DC with the treatment gas results. The advantage of this mode of operation is a rapid increase in bulk solids temperature even if small amounts of treatment gas are used.

The invention Device and the inventive method can be an independent process step for thermal treatment, such as heating, cooling, drying, conditioning, Crystallizing, degassing, representing bulk materials, or used in combination with further process steps. For example, a use in crystallization equipment, for solid phase polycondensation, for drying or for monomer degassing possible.

The invention Device can do this independently be set up by other process equipment or in a complex Process apparatus to be integrated. Thus, the inventive device for Example as a heating stage before a shaft reactor or as a cooling stage be arranged after a shaft reactor. Another combination uses the inventive Device for homogenizing after a fluidized bed apparatus.

The process gases used in various apparatuses or apparatus parts can independent be used from each other or coupled together.

Further advantages, details and applications can be described below NEN figures are taken, wherein:

1 a schematic sectional view along a vertical sectional plane of a first embodiment of the inventive device;

2 shows a section of a stowage element layer according to a second embodiment of the device according to the invention;

3a . 3b and 3c are schematic views according to a third, a fourth and a fifth embodiment of the inventive device;

4 a schematic representation of a segment of a Stauelementschicht according to a sixth embodiment of the inventive device is; and

5 is a schematic sectional view along a vertical sectional plane of the lower part of a seventh embodiment of the inventive device.

1 shows an inventive device with a treatment room ( 12 ), which faces upwards from a housing cover ( 10 ) and down from a perforated plate ( 15 ) is completed, and by a housing shell ( 11 ) is surrounded. In the ceiling area ( 18 ) there is a filling opening ( 13 ) for bulk material and a routing device ( 17 ) for treatment gas. In the ground area ( 16 ) there is a discharge opening ( 14 ) for bulk material. The perforated plate ( 15 ) acts as a supply device, through the treatment gas into the treatment room ( 12 ) flows. The discharge opening ( 14 ) is down through a rotary valve ( 24 ) shut off. In the treatment room ( 12 ) is a variety of grid networks ( 19a -N) as stowage element layers. In between, a large number of treatment layers ( 21a -N) each bounded above and below by a grid layer. Under the perforated plate ( 15 ) is a distribution room ( 22 ) for the treatment gas into which a feed opening ( 23 ) opens for treatment gas. The individual stowage element layers ( 19a -N) are on a support structure ( 26 ) attached. In the ceiling area ( 18 ) connects a flange ( 25 ) the housing jacket ( 11 ) with the housing cover ( 10 ). By loosening the flange ( 25 ), the device can be opened and the stowage element layers ( 19a -N) can be attached to the support structure ( 26 ) to the top.

2 shows a section of a stowage element layer ( 19 ) of a plurality of individual storage elements ( 20a -N), wherein the baffle layer is a grid of a plurality of wires. The minimum distance between the wires corresponds to the passage width (L _D ). The passage area comprises the sum of all mesh surfaces A _M between the damming elements ( 20a -N) plus the edge surfaces AR between the baffle elements and the housing shell ( 11 ) in relation to the free cross-sectional area in the treatment room.

3a . 3b and 3c show further possible constructions and arrangements of two stowage element layers ( 19a -B), between each of which a treatment room ( 21a ) is located. For the 3a and 3b along the section line L the passage width L _D and the storage element width L _{S is} visible, from which also the passage area can be calculated as the sum of all L _D multiplied by its length in relation to the free cross-sectional area in the treatment space.

3a shows a multitude of tubes as damming elements ( 20a -N), which are arranged offset from one layer to the next in each case by 90 °. The tubes can be flowed through by a heat transfer fluid, which passes through the inlet opening ( 28 ) is indicated.

3b shows a variety of slightly obliquely arranged baffles as damming elements ( 20a -N), which are each mirrored from one layer to the next.

3c shows a plurality of biconical bluff bodies which are connected from one baffle layer to the next by means of a rod. The baffles ( 20a -N) form a stowage element layer ( 19a ). The rods to the bluff bodies arranged underneath form a plurality of displacers in the treatment layer ( 21a ).

4 shows a segment ( 19a1 ) a stowage element layer ( 19a ). From a large number of such baffle element segments results in a round, in particular circular baffle element layer with a round, in particular circular recess for a displacement body in the middle. The individual storage elements ( 20b -N) are star-shaped on a support structure ( 20a ) built up.

5 shows the lower part of another device according to the invention, in which case the treatment room ( 12 ) is conically closed at the bottom and a transition into a plurality of outlet cones takes place, which in several discharge openings ( 14a -N). In the center of the treatment room ( 12 ) is a displacement body ( 27 ), through which a supply opening for treatment gas ( 23 ) with a treatment gas supply device ( 15 ) connected is.

example 1

In a cylindrical shaft with a process chamber with 0.24 cm ² cross-sectional area and a perforated plate arranged conically in the lower part (with 15 ° inclination to the horizontal) 22 sieves with a mesh size of 14 mm and a wire thickness of 3 mm are arranged at a distance of 5 cm, extending horizontally over the entire rector torfläche. The passage area through the wire mesh is thus 68%. In the center of the perforated plate, an outlet pipe with a diameter of 10 cm is arranged. In the outlet pipe a rotary valve is arranged. In the ceiling area, an inlet pipe with a diameter of 10 cm is arranged.

Of the Reactor is continuously from above with 600 kg / h of PET granules (3 mm in length 2.2 mm diameter) at 190 ° C fed. Through the screen plate is 765 Nm3 / h of air at 42 ° C and 83 mbar overpressure fed. The filling height is kept constant at 110 cm. For a loose bulk density of 714 kg / m3 the residence time 18.6 minutes. The residence time between two stowage element layers is 0.8 minutes.

The Product cools to 70 ° C off, the gas is heated to 158 ° C.

The Gas velocity increases from bottom to top from 1.0 to 1.4 m / s too.

Of the calculated relaxation point increases from bottom to top of 1.1 m / s to 1.2 m / s. Because the warming the gas and thus the gas velocity increase takes place rapidly, is the gas velocity in most of the reactor above that Loosening point.

The speed ratio VU / (VU + VO) is 12:40.

The Temperature equalization (TiP + TaP - TiG - TaG) / (TiP - TiG) is 0.41.

Example 2

example 1 was repeated with the difference that 670 Nm3 / h air with 44 ° C and 81 mbar overpressure supplied were.

The Product cools to 73 ° C off, the gas is heated to 177 ° C.

The Gas velocity decreases from bottom to top from 0.8 to 1.3 m / s too.

The speed ratio VU / (VU + VO) is 12:39.

The Temperature equalization (TiP + TaP - TiG - TaG) / (TiP - TiG) is 0.29.

Example 3

In a conical shaft with a process chamber with a lower one Cross sectional area of 0.15 cm 2, an upper cross-sectional area of 0.24 cm 2 and a in the lower part conical (with 60 ° inclination to the horizontal) arranged perforated plate are at a distance of 5 cm 22 sieves with a mesh size of 14 mm arranged, which horizontally over the entire reactor area extend. In the center of the perforated plate is an outlet pipe with 10 cm diameter arranged. In the outlet pipe is a rotary valve arranged. In the ceiling area is an inlet tube with 10 cm diameter arranged.

The reactor is charged continuously from above with 400 kg / h of PET pellets (3 mm length 2.2 mm diameter) at 190 ° C. 530 Nm3 / h of air with 48 ° C and 85 mbar overpressure are fed through the screen plate. The filling level is kept constant at 110 cm. With a loose bulk density of 714 kg / m3, the residence time is 22.2 minutes. The residence time between two stowage element layers is between 0.8 and 1.3 minutes.

The Product cools at 58 ° C off, the gas is heated to 165 ° C.

The Gas velocity increases from bottom to top from 1.1 to 1.0m / s from. The gas velocity in the stowage element layers increases from bottom to top from 1.6 to 1.5 m / s. The calculated relaxation point increases from bottom to top from 1.1 to 1.2 m / s. The gas speed in the baffle layer is above the loosening point, respectively.

The speed ratio VU / (VU + VO) is 12:53.

The Temperature equalization (TiP + TaP - TiG - TaG) / (TiP - TiG) is 0.25.

Comparative Example 1

A known from the prior art round fluidized bed apparatus with a process chamber with 0.3 m ² bottom surface is continuously charged with 600 kg / h of PET granules (3 mm length 2.2 mm diameter) at 190 ° C.

By the screen plate becomes 2945 Nm3 / h air with 42 ° C and 50 mbar overpressure fed. The filling level at rest is kept constant at 40 cm.

at a bulk density of 785 kg / m3 the residence time 9.4 minutes.

The Product cools to 70 ° C off, the gas is heated to 70 ° C, which in this case corresponds to a uniform bed temperature.

The Gas speed is while 3.4 m / s. The calculated loosening point is thereby 1.2 m / s too. The gas velocity in the reactor is thus above the Loosening point.

The Temperature equalization (TiP + TaP - TiG - TaG) / (TiP - TiG) is 1.

Comparative Example 2

One fluid bed apparatus with pulsator known from the prior art, with a process chamber with 0.3 m2 floor area is continuously using 600 kg / h of PET granules (3 mm length 2.2 mm diameter) at 190 ° C fed.

By the screen plate will produce 1434 Nm3 / h of air with 42 ° C and 20 mbar overpressure fed. The filling level at rest is kept constant at 20 cm.

at a bulk density of 785 kg / m3 the residence time is 4.7 minutes.

The Product cools to 70 ° C off, the gas is heated to 106 ° C.

The Gas speed is doing 1.7 m / s. The calculated loosening point is thereby 1.2 m / s too. The gas velocity in the reactor is thus above the Loosening point.

The Temperature equalization (TiP + TaP - TiG - TaG) / (TiP - TiG) is 0.76.

Comparative Example 3

In Example 1 of the patent DE 27 23 549 , Gey, are arranged in a shaft reactor with 0.07 m2 floor area sieves with a mesh size of 16 mm at a distance of 10 cm. The reactor is continuously charged with 30 kg / h of PET pellets (3 mm length 2 mm diameter) at 220 ° C.

the 46.5 Nm3 / h of air at 240 ° C are fed to the lower part of the reactor. The Filling height is 300 cm.

at a bulk density of 760 kg / m3 the residence time 322 minutes.

The Residence time between the sieves is 11 minutes.

The Product heated to 238 ° C, the gas cools to 220 ° C from.

The Gas speed is while 0.32 m / s. The calculated relaxation point is 1.3 m / s. The gas velocity in the reactor is thus below the loosening point.

The temperature equalization (TiP + TaP - TiG - TaG) / (TiP - TiG) is 0.05. Table 1 V _Gas / m _Prod V _gas dwell Temperature adjustment f (T) Nm ³ / h / kg / h m / s min Example 1 1.3 1.4 19 12:41 Example 2 1.1 1.3 19 12:29 Example 3 1.3 1.0 22 12:25 See Example 1 4.9 3.4 9 1 See example 2 2.4 1.7 5 0.76 See example 3 1.6 0.3 322 12:05

Out Table 1 shows that after in the prior art known methods either using large amounts of gas can achieve a rapid temperature, but what a bad Temperature adjustment leads, or when using smaller amounts of gas, a good temperature equalization reach, but that requires very long residence times.

In contrast, can be with the relatively simple embodiment the present invention, a rapid temperature control at the same time achieve good temperature equalization.

10

housing cover

11

housing jacket

12

treatment room

13

Filling opening for bulk material

14

Discharge opening for bulk material

15

feeding for treatment gas

16

floor area of the treatment room

17

removal device for treatment gas

18

ceiling area

19a-n

Storage element layers

20a-n

baffles

21a-n

treatment layers

22

distribution space for gas inlet

23

Feed opening for treatment gas in distribution room

24

rotary valve

25

flange in the ceiling area

26

support structure

27

displacement

28

supply line for heat transfer medium

Claims (42)

Device for treating a bulk material, comprising: - a treatment room ( 12 ) for receiving the bulk material; - at least one filling opening ( 13 ) through which the treatment room ( 12 ) is loadable with bulk material; - at least one discharge opening ( 14 ), through the bulk material from the treatment room ( 12 ) is dischargeable; At least one feeder ( 15 ) for a treatment gas in the soil area ( 16 ) of the treatment room ( 12 ); At least one way-out device ( 17 ) for a treatment gas in the ceiling area ( 18 ) of the treatment room ( 12 ); A plurality of stowage element layers ( 19a -N) in the treatment room ( 12 ), wherein between the stowage element layers a plurality of treatment layers ( 21a -N) and the stowage element layers have a passage area between 40% and 98%, characterized in that at least one stowage element layer ( 19 ) substantially over the entire cross section of the treatment space ( 12 ) and that at least one of the treatment layers ( 21 ) has a height of less than 100 mm and / or that at least one baffle element layer ( 19 ) by means of a separable connection in the treatment room ( 12 ) is arranged. Device according to claim 1, characterized in that the stowage element layers ( 19a -N) have transmission areas greater than 50%, in particular greater than 60% and / or less than 90%, in particular less than 80%. Device according to one of the preceding claims, characterized in that the stowage element layers ( 19a N) comprise nets, grids and grates or a plurality of individual baffles. Device according to one of the preceding claims, characterized in that between 3 and 100 stowage element layers ( 19a -N) in the treatment room ( 12 ) are arranged. Device according to one of the preceding claims, characterized in that more than 5, in particular more than 10, stowage element layers ( 19a -N) in the treatment room ( 12 ) are arranged. Device according to one of the preceding claims, characterized in that at least 5 stowage element layers ( 19a -N) over the entire cross-section of the treatment room ( 12 ). Device according to one of the preceding claims, characterized in that the treatment room ( 12 ) is arranged substantially vertically. Device according to one of the preceding claims, characterized in that at least one stowage element layer ( 19 ) substantially horizontally in the treatment room ( 12 ) is arranged. Device according to one of the preceding claims, characterized in that at least 5 treatment layers ( 21a -N) have a height of 10 mm to 300 mm. Device according to one of the preceding claims, characterized in that at least 5 treatment sheaths ( 21a -N) have a height of more than 20 mm, in particular more than 30 mm. Device according to one of the preceding claims, characterized in that at least 5 treatment layers ( 21a -N) have a height of less than 200 mm, in particular less than 100 mm. Device according to one of the preceding claims, characterized in that at least one stowage element layer ( 19 ) of a plurality of individual storage elements ( 20a -N). Device according to claim 12, characterized in that individual storage elements ( 20a -N) have cross-sectional areas of 0.05 cm ² to 20 cm ² , in particular 0.07 cm ² to 1 cm ² . Device according to one of the preceding claims, characterized in that it is in the individual storage elements ( 20a -N) are sheets, rods, wires or tubes or a combination thereof. Device according to one of the preceding claims, characterized in that at least one stowage element layer ( 19 ) consists of a grid or fabric of individual wires. Device according to Claim 15, characterized in that the individual wires a Thickness bigger than 2.5 mm. Device according to one of the preceding claims, characterized in that the damming elements ( 20a -N) of at least two stowage element layers ( 19a -N) offset and / or are arranged twisted to each other. Device according to one of the preceding claims, characterized in that the jacket ( 11 ) enclosing the treatment room is cylindrical. Device according to one of the preceding claims, characterized in that the jacket ( 11 ) enclosing the treatment space is at least partially conical. Device according to one of the preceding claims, characterized in that the jacket ( 11 ), which encloses the treatment space, is rotationally symmetric. Device according to one of the preceding claims, characterized in that in the treatment room ( 12 ) a displacer ( 27 ) is located. Device according to one of the preceding claims, characterized in that in the bottom area ( 16 ) of the treatment room ( 12 ) is a conical outlet area. Device according to one of the preceding claims, characterized in that a part of the floor area ( 16 ) of the treatment room ( 12 ) is limited downwards by a shut-off device, which has a passage area between 1% and 30%. Device according to one of the preceding claims, characterized in that above the at least one feed device ( 15 ) a further supply device for a treatment gas in the treatment room ( 12 ) is located. Method for the continuous, thermal treatment of a bulk material in a device, comprising: - a treatment room ( 12 ) for receiving the bulk material; - at least one filling opening ( 13 ) through which the treatment room ( 12 ) is loadable with bulk material; - at least one discharge opening ( 14 ) through the bulk material from the treatment room ( 12 ) is dischargeable; At least one feeder ( 15 ) for a treatment gas in the soil area ( 16 ) of the treatment room ( 12 ); At least one way-out device ( 17 ) for a treatment gas in the ceiling area ( 18 ) of the treatment room ( 12 ); A plurality of stowage element layers ( 19a -N), which can be flowed through both the treatment gas, as well as the bulk material in the treatment room ( 12 ), wherein between the stowage element layers a plurality of treatment layers ( 21a -N), characterized in that the flow velocity of the process gas in at least one stowage element layer ( 19 ) is above the loosening point of the bulk material. A method according to claim 25, characterized in that the flow velocity of the process gas in at least 5 stowage element layers ( 19a -N) is above the loosening point of the bulk material. Process according to one of the claims 25 or 26, characterized in that the flow velocity of the process gas between 10% and 150%, in particular between 20% and 75% above the relaxation point of the bulk material lies. Method according to one of claims 25 to 27, characterized in that the flow rate of the process gas in at least one treatment layer ( 21 ) is above the loosening point of the bulk material. A method according to claim 28, characterized in that the flow velocity of Process gas in at least 5 treatment layers ( 21a -N) is above the loosening point of the bulk material. Process according to one of the claims 28-29 characterized in that the flow velocity of the process gas between 1% and 100%, in particular between 2% and 50%, above the Loosening point of the bulk material lies. Method according to one of claims 25 to 30, characterized in that the average residence time in a treatment layer ( 21 ) is between 0.05 and 10 minutes, in particular more than 0.1 minutes and less than 5 minutes. Method according to one of claims 25 to 31, characterized in that at least one stowage element layer ( 19 ) by means of a separable connection in the treatment room ( 12 ) is arranged. Process according to one of the claims 25 to 32, characterized in that the stowage element layers have a passage width that is 4 to 40 times larger as the average bulk particle diameter. Process according to one of the claims 25 to 33, characterized in that it is the bulk material to granules with a mean diameter of 0.4 mm to 5 mm and the stowage element layers has a passage width of 4 mm to 50 mm. Process according to one of the claims 25 to 34, characterized in that it is the bulk material to particles, in particular granules, of a polycondensate, such as for example, polyamide, polyester, polycarbonate, polylactide, polyhydroxyalkanoate or their copolymers or mixtures, in particular polyethylene terephthalate or one of its copolymers. Process according to one of the claims 25 to 35, characterized in that the flow velocity of the process gas between 0.5 and 4 m / s, in particular between 0.7 and 2 m / s empty tube velocity is. Process according to one of the claims 25 to 36, characterized in that it is the bulk material to granules with a mean diameter of 1.4 mm to 5 mm acts and the flow rate the process gas in at least one treatment layer between 0.7 and 4 m / s, in particular between 0.8 and 2 m / s, empty tube velocity is. Process according to one of the claims 25 to 37, characterized in that the flow velocity of the process gas in at least one treatment layer in the lower region of the treatment space has a value VU and that the flow rate of the process gas in at least one treatment layer in the upper region of the treatment space has a value VO, where VU and VO are not significantly different and over the relation VU / (VU + VO) = 0.33 to 0.67, in particular, VU / (VU + VO) = 0.39 to 0.61, related to each other. Process according to one of the claims 25 to 38, characterized in that the bulk material the treatment room flows through from top to bottom. Process according to one of the claims 25 to 39, characterized in that the flow velocity of the process gas in at least one treatment layer in the floor area of the treatment room between 0.7 m / s and 2 m / s empty tube speed and the flow rate the process gas in at least one treatment layer in the upper Area of the treatment room is at least 20% larger and between 1.5 m / s and 4 m / s empty tube speed. Process according to one of the claims 25 to 40, characterized in that the treatment gas a Inlet temperature TiG and an outlet temperature TaG, that the bulk material has an inlet temperature TiP and an outlet temperature TaP and the thermal treatment is such that TaP substantially to TiG and that TaG is substantially similar to TiP, where the relationship (TiP + TaP-TiG-TaG) / (TiP-TiG) less than 0.5, in particular less than 0.4, is met. Method according to one of claims 25 to 41, characterized in that the device ge according to at least one of claims 1 to 24 is executed.