GB2116869A

GB2116869A - Moving bed filter

Info

Publication number: GB2116869A
Application number: GB08307503A
Authority: GB
Inventors: Gerhard Max Neumann; Hans Henrich Stiehl; Hans Joachim Lippold; Peter Hayn; Wolfgang Mathewes
Original assignee: Delbag Luftfilter GmbH
Current assignee: Delbag Luftfilter GmbH
Priority date: 1982-03-19
Filing date: 1983-03-18
Publication date: 1983-10-05
Also published as: FR2523471B1; FR2523471A1; DE3210683A1; JPS58174219A; GB8307503D0; GB2116869B

Abstract

Moving bed filter for separating vaporous and/or gaseous media from substances, has a layer 2 of contact agent through which the medium flows in an upwards direction, with at least one flow-guide member 5 arranged in the region of the layer over the entire cross-section and with at least one shut-off device 6. The flow-guide members 5 comprise funnel-shaped members 11 arranged in one plane in the manner of grating, which members 11 are attached to or in a grille. The shut-off device may comprise a system of horizontally movable bars 13 closing the open-ends of the funnel-shaped members or a perforated plate. <IMAGE>

Description

SPECIFICATION Moving bed filter for separating vaporous and/or gaseous media from substances The invention is based on a moving bed filter for separating vaporous and/or gaseous media from substances, of the type with a layer of contact material through which the medium flows in an upwards direction, with at least one flow-guide member arranged in the region of the layer over the entire cross-section and with at least one shut-off device.

In known moving bed filters, a layer of contact agent consisting of fluid material is located between an inlet and outlet opening for the flowing medium.

The saturated contact agent is discharged in a downwards direction and the layer of contact agent is refilled from above with fresh contact agent from a reservoir. The gaseous medium flows upwards through the granular absorbing layer of contact agent, in which case the latter, namely the adsorbent, becomes constantly enriched with the substances to be kept back from the gaseous medium, in the same direction, namely in the upwards direction.

The adsorbent or contact agent used up by this process is discharged in a downwards directon on reaching a certain saturation limit and at the same time is re-filled with fresh contact agent from above.

In order to be able to control the quantity of contact agent to be discharged, it is known to provide roof-shaped, concealed, open flow-guide members over the entire cross-section in or below the layer of contact agent which if necessary can be closed off and opened as desired on the underside. Furthermore, movable latticed discharge grids in conjunction with rhombisflow-guide members are known. It is a drawback in the devices known hitherto that the mass flow movement of the fluid contact agent can be influenced to an extraordinary high degree by the respective geometry of the components described, by the structure of the housing, by the thickness of the layer and by the nature of the contact agent and by the respective quantity of contact agent to be discharged per unit time.A uniform, even and economical exchange of the layer in a downwards direction is frequently prevented by resulting slipping and sticking areas and displacement forces of the particles of contact agent with nuclear flow effects in the pouring. Moreover, disadvantageous outstripping processes occur during the discharge stage between the particles of contact agent having various degrees of saturation. Due to these mechanisms of flow, an irregular exchange of the layer occurs. The contact agent is not fully utilized and consequently complete saturation of the adsorbent cannot be ensured.

It is the object of the invention to obviate the drawbacks of known moving bed filters of this type and to reduce the expenditure regarding apparatus and irrespective of the geometry of the moving bed filter housing and the height of the contact agent layer, to produce flow-guide member arrangements controlling the mass flow and which can be regulated, in order to make the moving bed filters more economical and to increase the availability of such installations.

According to the present invention there is provided moving bed filter for separating vaporous and/or gaseous media from substances, with a layer of contact agent through which the medium flows in an upwards direction, with at least one flow-guide member arranged in the region of the layer over the entire cross-section and with at least one shut-off device, wherein the flow-guide members comprise funnel-shaped members arranged in one plane in the manner of grating, which funnel-shaped members are attached to or in a grille.

Due to the construction of the flow-guide members according to the invention and their arrangement, irrespective of the cross-sectional area, a constant and lasting horizontal flow plane of the loose layer is not impaired even by several discharge processes. Due to the arrangement of a plurality of funnel members lying one beside the other, conditions as regards mass flow are created in the discharge grating surface, even over relatively large areas, which promote good flow and running properties of the granular contact agent. In this case, outstripping operations of used and fresh contact agent are precluded. The formation of slipping and sticking areas with nuclear flow disturbances, which was a drawback hitherto, no longer occurs at the time of the discharge operation.Due to the funnel grating surface divided uniformly into square areas, on which the contact agent confined by the shut-off device is deposited, uniform compression of the contact agent located thereabove is achieved over the entire cross-sectional area of the adsorbent bed, without additional vibration.

Advantageous developments and improvements are possible due to the measures described in the sub-claims. The various embodiments of the flowguide members and their arrangement allow any possible adaptation of the discharge grating surface to the flow behaviour, even with varied types and granulations of the contact agent.

Several embodiments of the moving bed filter according to the invention are illustrated in the drawings and are described in detail in the following description.

Figure 1 is a section through a moving bed filter with the flow-guide member arrangement according to the invention; Figure 2 is a perspective view of a first embodiment of a flow-guide member arrangement with shut-off device; Figure 3 is a section through the arrangement of the flow-guide members according to Figure 2; Figure 4 shows a second embodiment of the flow-guide member arrangement according to the invention with shut-off device; Figure 5 shows a development of the notched triangular section according to Figure 6; Figure 6 is a section through triangular sections inserted one in the other to form a flow-guide member arrangement; Figure 7 is a plan view of the triangular section arrangement according to Figure 6;; Figure 8 is a section through double triangular sections fitted one in the other as a further embodiment of a flow-guide member arrangement and Figure 9 is a plan view of the double triangular section arrangement according to Figure 8.

Figure 1 shows a moving bed filter. Located in the container 1 is a layer 2 of contact agent, through which the gaseous medium, which is represented by the arrows 3, flows from below. The purified medium is in turn discharged through the discharge pipe 4. The flow-guide member arrangement 5 limits the layer of contact agent 2 and can be opened and closed by way of the shut-off device 6. When the shut-off device 6 is open, saturated contact agent 2 flows into the discharge hopper 7.

Figure 2 shows a flow-guide member arrangement Sin more detail. Individual funnel members 11 are inserted from above into a commercially available grille, which consists of longitudinal and transverse bars 9, The funnel members 11 are clamped, welded, suspended, stuck or anchored in any other way in the grille 8. The shut-off device 12 is formed by T section bars 13, which are able to move parallel to the transverse bar 10. The funnel members 11 are constructed as angular truncated pyramids, but they may also have any other similar shape. By way of example, a funnel member 11 is provided with perforations 14, which ensure throughflow of the gaseous medium, but in which case the perforations 14 are so small that any passage of the contact agent cannot occur.

Figure 3 shows the flow-guide member arrangement 5 and the shut-off device 12 in section, in which case two funnel members 11 are filled with contact agent 2 by way of example. In the illustrated position of the shut-off device 12, the T-shaped bars 13 confine the contact agent 2. If the shut-off device 12 is moved horizontally in the illustrated direction 15, the lower openings 16 of the funnel members 11 are opened and the contact agent 2 is discharged downwards. Irrespective of the open and closed position of the shut-off device 12, the gaseous medium 3 flows unimpeded in an upwards direction through the perforations 14 of the funnel members 11 serving as inlet openings. The surface of the lower opening 16 of the funnel member 11 is somewhat smaller or equal to half the surface of the upper opening 17.The side faces of the funnel members 11 form an angle of between 15 and 350 with respect to the vertical. The bars 9, 10 of the grille 8, which have a thickness of 1.5 to 3 mm and a height of up to 80 mm, form square areas. The centre to centre spacing of the inserted funnel members 11 amounts to between 20 to 100 mm. Besides relatively large or relatively small dimensions, it has proved advantageous if the spacing on the grille is 50mm x 50mm for example and at the funnel inlet ~ 46mm46mm x 46mm and at the funnel outlet ~ 20mm x 20mm.

Thus ~ 85% of the total area of cross-section of the container 1 is available to the contact agent as "inlet cross-section" in the grille, which fills the entire cross-section of the container, due to which transverse movements of the contact agent are largely avoided at the time of discharge.

Naturally, instead of the perforations 14, the funnel members 11 may also be provided with slots.

For example, slots 14a may be provided in each funnel wall, which are contracted towards the inside or selectively towards the outside 14b.

Then, the contact agent 2 cannot drop through the slots 14a, whereas the gaseous medium 3 is able to flow through at any time. Also, in order to improve the throughflow of the medium 3, the shut-off device 12 can be perforated, provided with holes or slots.

Also, the shape of the bars is given solely by way of example. A perforated or non-perforated U section, a corresponding angle section or a section of any cross-section may also be used. For the sake of better fitting or clamping of the funnel members 11 in the bars 9,10 of the grille 8, in the upper region, the funnel members 11 may have vertical side edges, adjoining which at a corresponding angle are the inclined sides of the funnel.

Figure 4 shows a further embodiment for the flow-guide member arrangement 5 and for the shut-off device 12. in this case, the funnel members are constructed as pyramid-shaped members 18 tapering to a point in the upwards direction. The pyramid-shaped members 18 are arranged on the bars 9,10 of the grille 8 staggered in the manner of a chess board. Only one opening in the grille 8 is provided respectively between four pyramid-shaped members. Serving as a shut-off device 12 is a plate 19 comprising square holes in the manner of a chess board, which comprises open and closed surfaces according to the chess board pattern. The plate 19 with holes is moved to and fro in a direction 20, in which case the saturated contact agent is discharged in a downwards direction or the open areas lie below the pyramid-shaped members 18 and with the closed areas restrict the flow of contact agent.Also, in the example according to Figure 4, the pyramidshaped members 18 and/or the closed surfaces of the plate 19 with square hoels may be provided with a perforation.

In a further embodiment according to Figures 5 to 7, the funnel members 11 and the grille 8 are formed by two triangular sections 21,22 fitted one in the other. In this case, the transverse triangular section 21 which is either perforated or not perforated is arranged continuously in the shape of a roof and the triangular section 22 provided longitudinally with respect thereto is notched in accordance with the shape of the triangular section 21 arranged at right angles, in order that both sections 21,22 can be fitted one in the other. The lower funnel opening 23 is square and according to the embodiments of Figures 2 to 4 may be closed off by a shut-off device 12.

Figure 5 shows the development of the notched triangular section 22, to which clamping tongues 24 are attached on the broad side, which prevent the triangular sections 21,22 from being moved and falling out and are intended to clamp them with respect to each other. As can be seen from Figures 6 and 7, by bending the clamping tongues 24 through 90 , the continuous triangular sections 21,22 are locked immovably, if the lower edges of the transverse triangular sections 21 coincide with those of the clamping tongues 24 of the longitudinal triangular sections 22. Both triangular sections may also be perforated for the sake of better flow of the medium 3. Preferably, either the transverse or longitudinal triangular sections 21,22 which are not notched are perforated, in order that the strength of the funnel shape arrangement is ensured.

Figures 8 and 9 show a further embodiment in which the longitudinal and transverse triangular sections are constructed as double triangular sections 25,26, which according to the embodiment of Figures 5 to 7 are fitted one in the other in the form of grating in notches provided for this. The upper part 27 and the lower part 28 of the double triangular sections 25,26 are connected to each other by horizontal, constricted transition points. The rows of holes 29 extending transversely and longitudinally in the horizontal transition points 29a allow the flowing medium 3 to flow through freely, in which case, as shown in Figure 8, the contact agent 2 cannot flow through these holes 29.

Figure 1 shows only one flow-guide member arrangement 5 and one shut-off device 6, naturally, several different funnel shape arrangements, but in particular also several flow-guide member arrangements 5 may be provided, lying one above the other.

Claims

1. Moving bed filter for separating vaporous and/or gaseous media from substances, with a layer of contact agent through which the medium flows in an upwards direction, with at least one flow-guide member arranged in the region of the layer over the entire cross-section and with at least one shut-off device, wherein the flow-guide members comprise funnel-shaped members arranged in one plane in the manner of grating, which funnel-shaped members are attached to or in a grille.

2. Moving bed filter according to claim 1, wherein the grille comprises longitudinal and cross bars, in which funnel-shaped members of round, angular and/or square cross-section with the point directed downwards are engaged, for example suspended, hooked, clamped, welded or stuck or pulled through in one piece.

3. Moving bed filter according to claim 1,wherein the funnel members are constructed as pyramid members with the apex directed upwards, which are staggered alternately on the surface of the grille between bars so that pyramid members and openings alternate in the griile.

4. Moving bed filter according to any one of claims 1 to 3, wherein the shut-off device closing off the funnel members is constructed as a system of bars comprising angle, T or U sections able to move in the horizontal plane, in which case in one end position the contact agent is completely prevented from trickling through and in the other and position mayflowdownwards in an unimpeded manner through the funnel members.

5. Moving bed filter according to any one of claims 1 to 3, wherein the shut-off device is constructed as a plate perforated with mutually perpendicular rows of square apertures and with adjacent apertures of each row being spaced from each other by a square closed surface, said plate being able to move in the horizontal plane, which in one end position completely confines the contact agent between the pyramid members and in the other end position allows it to pass in an unimpeded manner.

6. Moving bed filter according to anyone of claims 1 to 5, wherein the funnel members and/or the parts of the shut-off device comprise passages for the flowing medium in the form of holes and/or slots arranged in the manner of a sieve, which are constructed so that the particles of contact agent cannot trickle through.

7. Moving bed filter according to claim 6, wherein the open surface area due to the holes and/or due to the slots distributed over the entire surface of the grille, amounts to between 15 and 70% of the surface of the grille.

8. Moving bed filter according to one of claims 1, 2 or 4to 7, wherein the centre to centre spacing of funnel membertofunnel member amounts to approximately 20 to 100 mm and the funnel members have an approximate height of 20 to 80 mm.

9. Moving bed filter according to any one of claims 1 to 8, wherein the grille comprises longitudinal and cross bars having a thickness of approximately 1.5 to 3 mm and a height of approximately up to 80 mm.

10. Moving bed filter according to any one of claims 1,2 or 4 to 9, wherein the surface of the lower opening of the funnel member is somewhat smaller than or equal to half the surface of the upper inlet opening.

11. Moving bed filter according to any one of claims 1,2 or 4 to 10, wherein in the upper region, the funnel members have straight vertical edges with a height of approximately 5 to 20 mm, adjoining which are inclined funnel sides with an angle to the vertical of approximately 15 to 350

12. Moving bed filter according to any one of claims 1,4 to 8 or 10 wherein the funnel member shape and the grille shape are formed from triangular sections which are continuous transversely and of notched triangular sections which are continuous longitudinally, which are fitted one in the form of grating and thus produce a funnel-shaped intersection contour with surface permeability greater than 50% of the total grille surface.

13. Moving bed filter according to claim 12, wherein the triangular sections which are continuous transversely are porous or have small perforations and the notched triangular sections which are continuous longitudinally are not perforated.

14. Moving bed filter according to claim 12, wherein the triangular sections are constructed as double triangular sections, in which case the horizontal constricted transition points from the upper part to the lower part of the double triangular sections are perforated with through holes.

15. Moving bed filter according to one of claims 12 to 14, wherein the triangular sections are mutually secured and clamped by attached clamping tongues.

16. Moving bed filter substantially as hereinbefore described with reference to any one of the accompanying drawings.