DE102007032019A1 - Reactor for adsorptive cleaning of air in a device for cryogenic separation of air, comprises a ring-shaped bed within a jacket, and an outer and an inner vessel having an axial direction and a radial direction - Google Patents

Abstract

The reactor for adsorptive cleaning of air in a device for cryogenic separation of air, comprises a ring-shaped bed (3) within a jacket (2), and an inner (4) and an outer vessel (5) having an axial direction and a radial direction. The reactor is symmetrically cylindrical built around a vertically running tank axis (1) and the jacket. The bed is filled with a packable material and is delimited by the inner and the outer vessel. The first one of the two vessels is rigid in the first of the two directions. The first vessel has a first and a second layer. The reactor for adsorptive cleaning of air in a device for cryogenic separation of air, comprises a ring-shaped bed (3) within a jacket (2), and an inner (4) and an outer vessel (5) having an axial direction and a radial direction. The reactor is symmetrically cylindrical built around a vertically running tank axis (1) and the jacket. The bed is filled with a packable material and is delimited by the inner and the outer vessel. The first one of the two vessels is rigid in the first of the two directions. The first vessel has a first and a second layer. The first layer is built as a radially rigid support vessel that is composed of a sheet-like material that has openings. The second layer is designed as a filter vessel that is also composed of sheet-like material. The holes in the sheet-like material of the filter vessel are narrower than the holes in the sheet-like material of the support vessel. The support vessel and the filter vessel are stretchable along the axial direction and the radial direction respectively. The second layer is placed in a gliding manner with respect to the first layer along a part of the axial extension of the bed. The second layer is composed of two axial sections, which adjoin or overlap one another. The first section of the second layer is non-positively connected with the first layer at an axial end by application of force. The other axial end of the first section of the second layer is placed in a gliding manner with respect to the first layer. Two adjoining sections of the second layer are built in an overlapping manner and are placed in a gliding manner with respect to one another. The first- and the second layer are composed of two sections respectively. A section of both the layers are held at an end by a common fastening device.

Description

The The invention relates to a reactor which is substantially cylindrically symmetric is constructed around a substantially vertically extending container axis and a jacket and inside the shell has an annular bed, which with free-flowing Material filled is and is bounded by an inner and an outer basket, the have an axial preferred direction and a radial preferred direction, wherein at least a first of the two baskets in at least a first the two preferred directions is rigid, the first basket a first and a second layer, and the first layer as radial rigid support basket is formed, which is formed of sheet-like material, the openings having.

Such a reactor is for example off EP 402783 B1 known.

For such Reactors have a wide scope. They can be for the most diverse Reactions between a gas and an active material, which in free-flowing Form is present, are used. The active material may be, for example an adsorbent or a catalyst. The reactor can have several Types of active material included and made up of more than one bed consist. A bed becomes concentric in this case from the neighboring one enclosed. The reactor then has more than two baskets. For n beds is the Number of baskets at least n + 1.

During one Reaction or adsorption phase is a reaction gas in about radial to the symmetry axis of the reactor through the active, free-flowing material filled Bed led, by, for example, the space between the mantle and the outer basket forwarded and recovered from the space inside the inner basket is deducted. In the case of an adsorption reaction decreases the reactivity of the active material (adsorbent) with increasing reaction time from. Therefore, the adsorbent must be regenerated at regular intervals become. While the regeneration phase becomes a regeneration gas, which is opposite to the to be cleaned gas deviating chemical composition and / or has a different thermodynamic state through which fill made of active material.

The For example, reaction can result from adsorptive separation of gas mixtures or in an adsorptive removal of undesirable components from a to be cleaned gas. A practical example of the latter is the separation of water and / or carbon dioxide from air at the entrance a cryogenic air separation plant. The pourable Material which is introduced into the packed bed is, acts as an adsorbent in this case and can, for example consist of a molecular sieve.

During the Adsorption phase is passed to the air to be purified through the bed and while delivering water and / or carbon dioxide to the active material. While The regeneration phase becomes the substances removed from the air desorbed by a regeneration gas, such as nitrogen, through the bed is passed with the adsorbent. This rule in general other temperatures and / or pressures as while the adsorption phase.

One Reactor of the type mentioned above can also be used for catalytic reactions be, for example, for the removal of NOx from the exhaust gas of Incinerators. The free-flowing Bed material in this case consists, for example, of metal-doped Molecular sieve particles.

The Term pairs "rigid" and "stretchy" refer here not on the intrinsic properties of the material itself elasticity or temperature, but on the possibility of length changes due to the external shape of the body, in this case a basket. A more rigid in a certain direction body is quite capable in this sense for example, with temperature changes expand. For example, a corrugated sheet is rigid in the direction the wave troughs and stretchable in the direction perpendicular thereto. One on a cylinder jacket bent corrugated iron, in which the troughs on circles around the cylinder axis are stretchable in the axial direction and in tangential and thus rigid even in the radial direction. A coil spring is in this Sense axially expandable and radially rigid.

The Orientations "axial" and "radial" refer to the container axis.

In DE 39 39 518 A1 It has already been proposed to produce a basket for such a reactor by a combination of a perforated plate and support rings. The perforated plate is designed to be stretchable in both preferred directions. The support rings make the basket rigid in the radial direction. The restraint of the flowable material takes over the perforated plate here. Its openings must therefore be relatively narrow. For larger reactor diameters and thus increasing sheet thicknesses, this is increasingly difficult to manufacture.

Out EP 402783 B1 It is known to form a basket of a combination of a relatively coarse perforated sheet and a superior wire mesh. Again, the openings in the perforated plate can not be significantly less than in the aforementioned embodiment. It also requires egg high effort to connect a wire mesh with the support basket.

Of the Invention is based on the object, a reactor with a basket construction to find that too for at big Reactor diameters is economical to manufacture and still has good operating characteristics.

These Task is solved by that the second layer is designed as a screen basket, which also is formed of sheet-like material, wherein the openings in the foil-like material of the strainer narrower than the openings in the film-like material of the support basket.

at The invention thus both layers of the first basket from foil-like Material, such as sheet metal, formed. The sieve basket is on the side of the support basket arranged, which is oriented towards the interior of the bed, and points relatively narrow holes on. In particular, the width of the openings must be so small that the strainer the free-flowing Retains material. Under "width" is here for this Effect decisive measure too understand. For circular openings the "width" is equal to the hole diameter.

For example are the openings in the support basket 2 to 50 times, preferably 4 to 20 times as wide as those in the strainer basket.

Since the retention function is taken over by the strainer basket, it no longer needs to be taken over by the support basket. This can therefore be provided with much larger openings. The openings in the support basket, for example, the EP 402783 B1 Have shape and arrangement, but have significantly larger dimensions. As a result, even with the use of particularly high wall thicknesses, it is possible to produce the support basket economically and to design it for particularly large bed diameters. In production, no elaborate perforation processes such as laser or water jet cutting must be used, but the application of relatively inexpensive methods such as punching is sufficient.

in the Generally, the strainer also has a smaller thickness than the support cage on. For example, the material of the support basket is 2 to 100 times, preferably 4 to 50 times Thick as that of the strainer basket.

Preferably is the support basket in the second preferred direction, in particular in the axial direction, stretchable. in principle the invention is also with axially rigid and radially expandable and even with both axially and radially rigid support baskets executable. in the In general, the support basket but radially rigid and axially expandable.

• (a) axial und radial starr
• (b) axial starr und radial dehnbar
• (c) axial und radial dehnbar
• (d) axial dehnbar und radial starr

With regard to its spring properties in the two preferred directions, the screen basket can basically assume any of the following properties:

• (a) axially and radially rigid
• (b) axially rigid and radially expandable
• (c) axially and radially extensible
• (d) axially extensible and radially rigid

Basically, support and Sieve basket be rigidly interconnected. In many cases it is but cheaper, if at least over a part of the height of the bed sliding the second layer relative to the first layer is stored. As a result, mechanical stresses between the avoided both layers. ("Height" becomes synonymous here used with "axial extent".) In one concrete example is the screen basket made of a single perforated plate formed and can over slide its entire axial extent on the support basket.

Of the Strainer basket has to be over the entire height extend the bed to fulfill its retention function. He may consist of a perforated plate that passes over the entire height of the bed. In many cases However, it is cheaper if the second layer consists of at least two axial sections, which adjoin or overlap one another. For example, the second layer has 1 to 50, preferably 1 to 20 axial sections.

Everyone these sections are ring-shaped trained and covered a part of the axial extent (height) of the bed. The different Sections can be identical or different with each other.

Here is it cheap if at least a first section, preferably all sections the second layer at one axial end frictionally with the first layer are connected. For example, the bottom edge one or more portions of the strainer basket attached to the support basket be, for example, by one or more welded joints. in principle For example, the first portion of the second layer may also be at other locations force fit be connected to the first layer.

In In another embodiment, the first portion of the second Layer at its other axial end relative to the first layer slidably mounted. Even with different thermally induced Expansions of the two layers thereby become mechanical stresses further reduced.

In addition, two adjacent sections of the second layer may be formed overlapping, wherein the two sections relative zueinan which are slidingly mounted. For example, the lower edge of each portion of the second layer is adhered to the first layer and the upper edge is slidable relative to the first layer and opposite to the portion of the first layer that follows above. The different sections of the second layer thus overlap and slide relative to each other.

Preferably Both layers are built in approximately equal sections, wherein at least a portion of both layers on at least one End is held by a common fastening device.

The Invention also relates a use of the reactor according to claim 10 for the adsorptive purification of air, in particular in a device for the cryogenic separation of air.

The Invention and further details of the invention are hereinafter based on an embodiment shown in the drawings explained in more detail. in this connection demonstrate:

1 a section through the reactor of the embodiment along the container axis in a greatly simplified representation,

2 a first variant of the two layers of the basket of 1 in detail (longitudinal section along the container axis),

2A a support basket in detail,

2 B a sieve basket in detail and

3 a second variant of the two layers of the basket of 1 in detail (longitudinal section along the container axis).

1 shows the basic structure of the exemplary embodiment of the reactor according to the invention. For the sake of simplicity, the illustration is very schematic, in particular the relationships between the external dimensions of the reactor and the material thickness do not correspond to the true dimensions.

The reactor is essentially cylindrically symmetric about the axis 1 built up. He is limited to the outside by a coat 2 which is an upper one 7 and a lower calotte 8th with entry 10 and outlet openings 9 for gas to be purified. The upper dome 7 is also by neck 11 pierced for filling and suction of free-flowing material.

Inside the reactor is an annular adsorption bed 3 arranged, which by two cylinder-shaped baskets, a first, outer 5 and a second, inner one 4 is limited. The bed 3 gets down through the floor 6 completed, which over star-shaped ribs 12 rigidly at the lower calotte 8th of the coat 2 is attached. The inner basket 4 is rigid with the ground at its lower end 6 connected. He also relies on the star-shaped ribs 12 on the lower calotte 8th of the coat 2 from. The outer basket 5 stands on the lower calotte 8th on, is welded to this and thus rigid with the coat 2 connected.

At least one of the baskets 4 . 5 is made of two layers of perforated sheet metal, in the concrete example this applies to both baskets 4 . 5 , Only at the ends can also occasionally unperforated plate used (oblique hatched sections). More about the structure of the baskets 4 . 5 is the 2 and 3 and the corresponding description text.

Inside the bed 3 there is a bed of free-flowing material. In the concrete use of the reactor is adsorptive material, as well could a free-flowing catalyst be filled.

The flow direction of the gas to be cleaned is in 1 indicated by arrows with solid lines (reaction or adsorption phase). In this case, the gas to be purified, for example air, flows over the inlet opening 10 into the reactor, is through the bottom of the soil 6 deflected while deposited dripping water. Subsequently, the gas to be cleaned in the outer annulus 15 between coat 2 and outer basket 5 directed. From there, the gas to be purified flows through the adsorption bed with a radial component 3 in the inner annulus 16 , This will except through the inner basket 4 also by a built-up of truncated cones displacement body 17 limited, the cross-section of the inner annulus 16 reduced. As a result, an approximately uniform current density of the gas to be cleaned in bed 3 ensured largely independent of the axial coordinate. Between the inner basket 4 and the displacement body 17 If necessary, it is a dust sieve 13 intended.

If a regeneration is necessary in the reaction, a regeneration gas, for example nitrogen, is conducted in the opposite direction during the regeneration phase (dashed arrows in FIG 1 ).

2 shows the structure of the outer basket 5 in detail (excerpts A of the 1 ). There are only two outer sections of the bed 3 shown, the symmetrical to the container axis 1 are arranged. Explained in detail is the detail of the outer basket shown in the drawing on the right 5 , According to the invention, this outer basket 5 built up of two layers. The first layer is through a support basket 20 , the second layer through a strainer basket 21 educated. The strainer basket is attached to the bed 3 facing side of the support basket 20 arranged.

The support basket 20 is in 2A shown in detail. He has long drawn openings, which are oriented tangentially. Thus, it is rigid in the radial direction and extensible in the axial direction.

The sieve basket 21 is in 2 B He has long drawn openings, which are axially oriented. Thus, it is stretchable in the radial direction and rigid in the axial direction.

support cage 20 and strainer basket 21 extend over the entire or substantially the entire height of the bed and are divided into a plurality of superposed cylindrical sections. The height of each section is the same, but can also be chosen differently.

In 2 is the transitional area between two such sections 100 . 101 which will be referred to as "upper section and lower section" hereinafter.

With an annular fastening profile 22 with T-shaped cross section are the upper and the lower portion of the support basket 20 connected by welding. The upper leg 23 of the fastening profile 22 connects the lower end of the upper section 100 of the strainer basket 21 by a clamping connection frictionally with the lower end of the upper portion of the support basket 20 , The upper end of the upper section 100 of the strainer basket 21 can be relative to the support basket 20 slide, especially in the axial direction. The holder is executed at this point as well. as below by the upper end of the lower section 101 is explained. In this way, the heat-induced axial movements of the support basket and screen basket are decoupled. While the support basket 20 is firmly clamped and thermal differences in length compared to the container wall compensated by its axial extensibility, the axially rigid screen basket 21 virtually regardless of its axial extent or contraction.

The lower thigh 24 the fastening profile is designed so that it prevents a tilting of the screen basket inwards, but not frictionally connects the screen basket with the support basket. The upper end of the lower section 101 of the strainer basket 21 can thus relative to the support basket 21 slide.

3 shows another embodiment of the transition region between two sections 200 and 201 , The fastening profile here consists of a solid outer ring 222 and a non-positively connected with this inner ring 222 , The lower ends of the upper section 200 from strainer basket 21 and support basket 20 are with the outer ring 22 welded, as well as the upper end of the lower section 201 of the support basket 20 , The upper end of the lower section 201 of the strainer basket 21 On the other hand, it is again slidably mounted and becomes through the inner ring 224 guided.

Alternative to the illustration in 3 For example, the inner ring may be extended upward above the outer ring and the lower end of the upper section 200 of the strainer basket 21 hold by clamping instead of by welding.

Claims (10)

Reactor which is substantially cylindrically symmetrical about a substantially vertically extending container axis ( 1 ) and a jacket ( 2 ) and within the shell an annular bed ( 3 ), which is filled with free-flowing material and by an inner ( 4 ) and an outer basket ( 5 ), which have an axial preferred direction and a radial preferred direction, wherein at least a first of the two baskets ( 4 . 5 ) is rigid in at least a first of the two preferred directions, the first basket ( 4 . 5 ) has a first and a second layer, and the first layer as a radially rigid support basket ( 20 ) formed of sheet-like material having openings, characterized in that the second layer is used as a screen basket ( 21 ) is formed, which is also formed of sheet-like material, wherein the openings in the film-like material of the strainer basket ( 21 ) narrower than the openings in the sheet-like material of the support basket ( 20 ) are. Reactor according to claim 1, characterized in that the support basket ( 20 ) in the second preferred direction, in particular in the axial direction, is extensible. Reactor according to claim 1 or 2, characterized in that the sieve basket ( 21 ) in the first preferred direction, in particular in the radial direction, is extensible. Reactor according to one of Claims 1 to 3, characterized that at least over a portion of the axial extent of the bed the second layer relative is slidably mounted to the first layer. Reactor according to one of claims 1 to 4, as characterized in that the second layer consists of at least two axial sections adjoining or overlapping one another. Reactor according to claim 5, characterized in that that at least a first portion of the second layer at a axial end frictionally connected to the first layer. Reactor according to claim 6, characterized in that that the first portion of the second layer at its other axial End is slidably mounted relative to the first layer. Reactor according to one of Claims 5 to 7, characterized that at least two adjacent portions of the second layer overlap are formed, wherein the two sections relative to each other are slidably mounted. Reactor according to one of Claims 5 to 8, characterized that the first and the second layer of at least two Sections, with at least a portion of both layers at least one end by a common fastening device is held. Use of the reactor according to one of claims 1 to 9 for the adsorptive purification of air, in particular in a device for cryogenic decomposition of air.