GB2047114A

GB2047114A - Filtering apparatus for dust-laden gas

Info

Publication number: GB2047114A
Application number: GB7930621A
Authority: GB
Original assignee: Intensiv Filter GmbH and Co KG
Current assignee: Intensiv Filter GmbH and Co KG
Priority date: 1979-04-24
Filing date: 1979-09-04
Publication date: 1980-11-26
Also published as: DE2916453B1; ES484279A1; DE2916453C2; NL7905617A; DK371979A; IT1122394B; SE7907585L; CH642562A5; FR2454833B1; ATA594279A; AT375840B; BE878690A; GB2047114B; IT7924857A0; YU212079A; SE434345B; FR2454833A1

Abstract

In a filtering apparatus comprising a plurality of filter bags (19), each bag (19) extends over a cage (18) and is supported at its upper end in a support base (14) forming a division between the dirty gas space below the base (14) and the clean gas space above the base (14). Also supported in the support base (14) are injectors, nozzles or inlet sockets (17) serving for the admission of scavenging gas for periodically cleaning the bags (19), the sockets (17) when in position within the bags (19) serving to seal the bags (19) to the base (14). Each bag (19) and its socket (17) may be releasably secured in the base (14) by three equi-spaced spreader levers (20) the short arms (20b) of which engage in a groove (18b) of a split ring (18a). The levers (20) are retained on the socket (17) by an elastic ring (21) and when the socket (17) is moved downwards to be secured in the base (14) the long arms (20a) of the levers (20) contact a flange (18a) at the upper edge of the split ring (18) so that the levers move over-centre and a seal is established between the filter bag (19), the ring (18) and the base (14). In another embodiment, the levers (20) are replaced by a slotted resilient frusto-conical member which moves over-centre when the socket (17) is inserted. <IMAGE>

Description

SPECIFICATION Filtering apparatus for dust-laden gas Technical field of the invention The invention relates to a device for securing injectors, nozzles or inlet sockets into a tube support base of filtering apparatus for dust-laden gas, having a group of filter tubes, which are closed at one end and open at the other, are drawn over supporting cages and are fixed in the tube support base, which is designed as a partition wall between the space for the dust-laden gas and the space for the purified gas, wherein the filter tubes are swept in a direction from the exterior thereof to the interor by the stream of dust-laden gas which is to be purified, and, by the aid of injectors, nozzles or inlet sockets are, in a periodic sequence, freed from dust adhering to the external surface of said tubes by a stream of scavenging gas directed in counterflow by a scavenging gas device, said filter tubes being arranged in a casing provided with an inlet port for the entry of dust-laden gas, a port for the exit of purified gas, and means for the extraction of dust, and wherein the filter tubes are sealed i such a matter to the tube support base by the injectors, nozzles or inlet sockets that no dust can penetrate from the dust-laden gas space into the purified gas space through the sealing surfaces between the filter tubes and the tube support base.

Injectors, nozzles and inlet sockets are components of filtering apparatus for dust-laden gas used in the art of gas purification, which are necessary for introducing with satisfactory efficiency a scavenging gas stream from the purified gas space into the individual filter tubes.

Background art In the known types of filter plants, these compo nexts are secured into the tube support base by means of a special seal or else, as is usual in most cases, by using th 3 periphery of the filter tube as a seal. For this purpose use is made of threaded connections, loops of spring wire, clamping bails, or special retaining devices having two or more levers as the operating means. By means of these elements the necessary sealing force is produced for sealing the filter tube with respect to the tube supportbase (GB7810568,GM7815811).

In all the conventional filter plants for dust-laden gas it is necessary to exchange the filter tubes from time to time because the installed tubes become worn, or react with the product to be filtered, or else when the product under treatment is to be changed the conditions are such that it is necessary to prevent the previously filtered product from coming into contact with the subsequently filtered product. The replacement of the filter tubes is a non-productive activity. Consequently these operations must be performed with the smallest possible expenditure of time. Almost always the type of assistance available for performing these operations is lacking in special expert knowledge. Any errors in the installation of the filter tubes must be avoided because imperfectly filtered tubes allow the access of dust.This infringes the existing environmental laws governing the oper ation of filter systems. Accordingly the exchange of filter tubes must be as simple as possible in its practical application.

Furthermore it is necessary to have access to the tube support base when exchanging the tubes.

Accordingly all installed devices and constructions restricting such accessibility are to be regarded as a disadvantage to the performance of rapid working and security against accidents.

Because a securing device is necessary for each filter tube, and in particular thousands of filter tubes may exist in a filter plant, especially large scale filter installations, a device which can be produced with the minimum of resources is very desirable.

In the conventional filtering plants the installation and dismantling operations for installing and chang ing the filtertubes with the presently used injectors, nozzles or inlet sockets, depending upon the con struction of the filter, are possible only with consid erable time expenditure. Thus several manipulations are necessary, e.g., the releasing and tightening of screw connections and the releasing, positioning and reinstalling of clamping elements. In such cases the elements themselves or their anchorages im pede the free access to the tube support base.

Moreover the introduction of anchorages for the elements upon the tube support base is substantially time consuming.

Disclosure of the invention The invention has as its primary object the provi sion-of an adequately rigid securing meansfor injectors, nozzles or inlet sockets in the tube support base offilters for dust-laden gas, which can effect a dust-tight joint between the filter tube and the tube support base, which can be installed with the minimum possible manipulations, which renders unnecessary the provision of any fittings and structures upon the tube support base which could impede accessibility and which can be manufactured with the minimum of technical resources. According to the invention this problem is solved in that the injectors, nozzles or inlet sockets are secured in the tube support base by means of spreader levers or spreader discs.

Further important features of the invention are described in the following. According to one feature, to which particular importance is attached, the spreader levers or spreader discs are arranged to be snapped over out of a stable position which they occupy prior to securement, through an unstable intermediate position before reaching a stable position after securement. In this arrangement the spreader levers or spreader discs are supported in a split ring.

The technical advance achieved by the present invention rests upon the following advantages. The injectors, nozles or inlet sockets can be installed or disassembled by only a single manipulation in a natural cycle of movement, namely fitting of the device by downward pressure and disassembly by pulling out. Each operation demands only a few seconds to time. During this time the spreader levers or spreader discs, by bearing upon the split ring cladding the upper edge of the filter tube, snap out of the stable initial position and pass through the unstable intermediate position into the stable end position. Because the spreader levers or spreader discs are still maintained under stress in the end position, there exists a radially directed force and an axially directed force.The radially directed force presses the filter tube into the wall of the hole in the tube support base and thereby creats a dust-tight joint. The axially directed force presses the injector, nozzles or inlet socket into the filter tube and thus effects the securing therein of the injector, nozzle or inlet socket. Moreover when dismanling the device, the spreader levers or spreader discs, upon with drawal of the inlet socket from the filter tube, again snap over by a single manipulative action out of the stable end position through the unstable intermedi ate position into the stable final position, whereby the formerly sealed and secured parts are released.

A further advantage is that the tube support base is free of obstructive securing elements, that is to say there are no structural elements restricting access to the tube support base.

In one practical form of the device to which importance is attached, the spreader levers are made of angular shape in cross section with a shorter limb and a longer limb.

To enable the spreader levers to snap over easily, they are secured to theinjectors, nozzles or inlet sockets by means of resilient rings. Preferably the resilient rings take the form of rings of round section material.

To ensure the snapping over into the installed condition, the initial position of the longer limb of the spreader lever is such that it bears against the split ring.

For the purpose of limiting the movement of the injector, nozzle or inlet socket, upon installing the same in the filter tube, it is arranged that the flange of the inlet socket bears upon the split ring when in the secured condition.

In order to avoid inadvertent snapping over of the spreader levers, guide member are provided which are mounted so as to extend laterally from the injectors, nozzles or inlet sockets, the outer edges of thse guide members projecting beyond the shorter limbs of the spreader lever in the position prior to the securement of the inlet sockets.

The radial and the axial directed force can be determined by the length of the shorter limb of the spreader levers so that different securing and sealing forces can be applied to suit various sizes of filter tubes.

In another practical form, to which importance is also attached, the spreader disc is made of resilient material. In order that the spreader disc can esily snap over between the initial position and the final position, it is designed as an angular conical shell with inner and outer slots.

The radially directed force for sealing the filter tube in place and the axially directed force for securing the device in the tube support base can be determined by selecting the magnitude of the cone angle, the elasticity of the material, the thickness thereof, the arrangement of the slots, and the magnitude of the difference between the outer diameter of the spreader disc and the inner diameter of the groove.

In order to ensure that the spreader disc can support itself whilst snapping over, the split ring is provided with an inwardly projecting peripheral lip at the level of the groove.

Embodiments of the invention are hereinafter described, by way of example, with reference to the accompanying drawings.

Brief description of the drawings Figure 1 is a cross section of a filter for dust-laden gas, Figure2 is a longitudinal section, partially broken away, of an inlet socket having spreader levers, according to a first embodiment of the invention, in the condition before the securement of the socket, Figure 3 is the inlet socket according to Figure 2 in the installed conditin, Figure 4 is a section along the line Il-Il of Figure 3, Figure 5 is a longitudinal section, partially broken away, of an inlet socket with a spreader disc, according to a second embodiment of the invention, in the condition efore being secured, Figure 6 is the inlet socket according to Figure 5 in the installed condition, and Figure 7 is a plan view of a part of a spreader disc.

Best modes for carrying out the invention A casing 10 has an inlet port 11 for the entry of a dust laden gas, a port 12 for the exit of purified gas and a device 13 for dust extraction, and the casing 10 is also provided with a tube support base 14which divides the casing into a chamber 15 for the dust laden gas and a chamber 16 forth purified gas. The tube support base 14 has openings in which there are arranged filter tubes 19, which are drawn over supporting cages 18, these tubes being open at the top and closed at the bottom. In these filter tubes there are installed injectors, nozzles or inlet sockets 17 according to the type of construction used, and which are provided with the securing device according to the present irvention.In the following description only the term inlet socket 17 will be used when describing the injectors, nozzles, or inlet sockets.

The dust laden gases to be filtered pass through the inlet port 11 into the casing 10 and thence pass throughthefiltertube 19 into the purified gas chamber 16 and then out of the outlet port 1. For the purpose of freeing the outer surface of the filter tubes from adherent dust, a scavenging gas device, not shown in he drawing, is used for passing scavenging gas in a periodic cycle in counterflow through the inlet sockets 17 into the filter tubes 19.

The released dust descends into the lower part of the casing 10 and is carried away through the gas extraction device 1:3.

In Figures 2 to 4 the inlet sockets 17 are provided with spreader levers 20, preferably three in number, which are regularly spaced at 120% By means of an elastic ring 21 the spreader levers 20 are, in the condition before securement, hed in a prismatic depression 17b in the socket in such a manner that the longer limbs 20a of the spreader levers 20 are positioned substantially horizontally as shown in Figure 2. Upon pressing down the inlet socket 17 into the secured position according to Figure 3 the spreader levers 20 are forced, by the impact of the longer limb 20a upon a split ring 18a of the support cage 18, to snap over so that the shorter limb 20b of the spreader lever 20 engages in a groove 18b of the ring 18a. The end position is limited by a flange 17c of the inlet socket.Upon pressing down the inlet socket 17, there is set up, by the shorter limb 20b, a radially directed force which is exerted to press the split ring 18a of the support cage 18 over its total periphery against the filter tube 19, which at this location is provided with a reinforcement 19a, having a rolled boss 19b.

By reason of the clamping effect exerted upon the filter tube 19 through the ring 18a and the groove 18b, a dust-tight joint is establishd between the filter tube 19 and the tube support base 14. In the installed condition the axial force exerted upon the shorter lever limb 20b of the spreader levers 20 presses down the flange 1 7c onto the ring 18a and thus effects the securing of the inlet socket 17 in the tube support base 14. The retaining and sealing forces can be individually predetermined by selecting the length of the shorter lever limb 20b. If the limb 20b is made longer the forces are increased but if it is shortened the forces become smaller.In the region of the spreader levers 20, the inlet socket 17 is provided with laterally directed guide membrs 17d which, as is clear from Figure 2, have their outer edges projecting beyond the limb 20b of the spread er levers 20 before the device is secured. In this way the guide members prevent an inadvertent snapping over of the spreader levers upon introducing the inlet socket 17 into an opening in the tube support base 14 and thus render the installation of the device fool-proof In the securing device illustrated in Figures 5 to 7 a spreader disc 22 is provided in place of the spreader lever 20. The resilient spreader disc 22, slotted as is shown in Figure 7, or in a similarly suitable manner, is introduced into an annular slot 17e of the inlet socket 17.Upon installing the inlet socket 17 by forcing the latter in a downward direction, the spreader disc 22 is brought into the snap-over position by an inwardly projecting peripheral lip 18c of the slotted ring 18a. This takes place at the moment when the pivoting points of the speader disc 22 in the annular groove 17e of the socket and in the ring groove 18b are situated at the same level. The spreading of the disc 22 causes a radial force to be exerted on the slotted ring 18a which then connects the filter tube 19 to the tube support base 14 in a dust-tight manner. The length of path which is moved through by the installing operation is limited by the peripheral flange 17c. In the installed condition according to Figure 6, an axial force is maintained which forces the flange 17c of the inlet socket 17 onto the slotted ring 18a, thereby effect the securing thereof.

In the condition before fitting, the spreader disc 22 has a predetermined outer diameter which is some what less than the inner diameter of the ring 18a.

This makes possible the easy introduction of the disc. The internal diameter of the spreader disc 22 and the arrangement of the slots proceeding therefrom are so designed that the disc can be introduced from below over the base of the inlet socket 17 and a guiding boss 17f into the ring groove 17e. The installation characteristics and the stressing and holding forces can be individually determined by selection of the magnitude of the cone angle a, the elasticity of the material, the thickness thereof, the slot arrangement and the magnitude of the difference between the outer diameter of the spreader disc 22 and the inner diameter of the groove 18b.

Without necessarily limiting the scope of the invention claimed, preferred embodiments of the invention may be summarised as follows: 1. A device for securing injectors, nozzles or inlet sockets into a tube support base of filtering apparatus for dust-laden gas, having a group of filter tubes which are closed at one end and open at the other, are drawn over supporting cages and are fixed in the tube support base, which is designed as a partition wall between the space for the dust-laden gas and the space for the purified gas, wherein the filter tubes are swept in a direction from the exterior thereof to the interior by the stream of dust-laden gas which is to be purified, and, by the aid of injectors, nozzles or inlet sockets are, in a periodic sequence, freed from dust adhering to the external surface of said tubes by a stream of scavenging gas directed in counterflow by a scavenging gas device, said filter tubes being arranged in a casing provided with an inlet port for the entry of dust-laden gas, a port for the exit of purified gas, and means for the extraction of dust, and wherein the filter tubes are sealed in such a manner to the tube support base by the injectors, nozzles or inlet sockets that no dust can penetrate from the dust-laden gas space into the purified gas space through the sealing surfaces between the filter tubes and the tube support base, characterized by the feature that the injectors, noz zles or inlet sockets (17) are secured in the tube support base (14) by means of spreader levers (20) or spreader discs (22).

2. A device according to Summary 1, characterized in that the spreader leavers (20) or spreader discs (22) are arranged to snap over out of a stable initial position, which they assume before the securing thereof and through an unstable intermediate position during fitting into a stable final position assumed after fitting.

3. A device according to Summary 2, characterized in that the spreader levers (20) and the spreader discs (22) are supported in a split ring (18a).

4. A device accoding to Summary 1 2 or 3, characterized in that the spreader levers (20) have an angular cross section with a shorter limb (20a) and a longer limb (20b).

5. A device according to one or more of Summaries 1 to 4, characterized in that the spreader levers (20) are secured to the injectors, nozzles or inlet sockets (17) by means of resilient rings# (21).

6. A device according to Summary 5, characterized in that the resilient rings (21) are constructed as rings of round cross section material.

7. A device according to one or more of Sum maries 1 to 6, characterized in that, in the initial position before fitting, the longer limb (20a) of the spreader lever (20) bears upon the-ring (18a).

8. A device according to-one or more of Summaries 1 to 7, characterized in that in the fitted condition the flange (17c) of the socket bears against the ring (18a).

9. A device according to one or more of Summaries 1 to 8, characterized in that the guide members (17d) are mounted laterally upon the injectors, nozzles or inlet sockets (17), the outer edges of which members project beyond the shorter Imbs (20b) of the spreader levers (20), when the latter are in their initial position before the securing of the sockets.

10. A device according to one or more of Summaries 1 to 9, characterized in that the radially directed force and the axially directed force are determinable by selecting the length of the shorter limbs (20b) of the spreader levers (20).

11. A device according to one or more of Summaries 1 to 3, characterized in that the spreader disc (22) consists of resilient material.

12. A device according to one or more of Summaries 1 to 3, and 11, characterized in that the spreader disc (22) is constructed as an annular conical shell with inner and outer slots.

13. A device according to one or more of Sum- maries 1 to 3, 11 and 12, characterized in that the radial force for sealing the filter tube (19) and the axial force for the securement thereof are individually determinable by selecting the magnitude of the cone angle a, the elasticity of the material, the thickness thereof, the slot arrangement and the magnitude of the difference between the outer diameter of the spreader discs (22) and the inner diameter of the groove (18b).

14. A device according to one or more of Summaries 1 to 3, and 11 to 13, characterized in that at the level of the groove (15b) the ring (18a) is provided with an inwardly projecting peripheral lip.

Although reference numerals have been used in the appended claims to improve the intelligibility of these claims, it is expressly stated that these reference numerals should not be construed as limiting the claims to the constructions illustrated in the accompanying drawings.

Claims

1. Filtering apparatus for dust-laden gas, having a casing (10) and a group of filter tube (19) which are closed at one end and open at the other end, extend over supporting cages (18) and are fixed in the casing (10) in a tube support base (14) which serves as a partition wall in the casing 10 between the space (15) for the dust-laden gas and the space (16) for the purified gas, the tube support base (14) also having secured therein injectors, nozzles or inlet sockets (17), in which apparatus, when in use, the filter tubes (19) are swept in a direction from the exterior thereof of the interior by the stream of dust-laden gas which is to be purified, and, by the aid of the injectors nozzles or inlet sockets (17), the filter tubes (19) can be, in a periodic sequence, freed from dust adhering to the external surface of said tubes (19) by a stream of scavenging gas directed in counterflow by a scavenging gas device, and in which apparatus said casing (10) is provided with an inlet port (11) for the entry of dust-laden gas into said dust-laden gas spaces (15), a port (12) for the exit of purified gas from said purified gas space (16) and means (13) for the extraction of dust, and the filter tubes (19) are sealed in such a manner to the tube support base (14) by the injectors, nozzles or inlet sockets (17) that no dust can penetrate from the dust-laden gas space (15) into the purified gas space (16) through the sealing surfaces between the filter tubes (19) and the tube support base (14), which apparatus is characterized by the feature that the injectors, nozzles or inlet sockets (17) are secured in the tube support base (14) by means of spreader levers (20) or spreader dics (22).

2. Apparatus, according to Claim 1, characterized in that the spreader levers (20) or spreader discs (22) are arranged to snap over out of a stable initial position, which they assume before the securing of the injectors, nozzles of inlet sockets (17) and through an unstable intermediate position during fitting into a stable final position assumed after the securing.

3. Apparatus, according to Claim 1 or Claim 2, characterized in that the spreader levers (20) and the spreader discs (22) are supported in a split ring (18a).

4. Apparatus, according to any preceding claim, characterized in that the spreader levers (20) have an angular cross section with a shorter limb (20a) and a longer limb (20b).

5. Apparatus, according to any preceding claim, characterized in that the spreader levers (20) are secured to the injectors, nozzles or inlet sockets (17) by means of resilient rings (21).

6. Apparatus, according to Claim 5, characterized in that the resilient rings (21) are constructed as rings of round cross section material.

7. Apparatus, according to Claims 3 and 4, characterized in that, in the initial position before the securing of the injectors, nozzles of inlet sockets (17), the longer limb (20a) of the spreader levers (20) bears upon the split ring (18a).

8. Apparatus, according to any one of Claims 3 to 7, characterized in that in the secured condition of the inlet sockets (17) a flange (17c) of the inlet sockets (17) bears against the split ring (18a).

9. Apparatus, according to any one of Claims 4 to 8, characterized in that guide members (17d) are provided laterally upon the injectors, nozzles or inlet sockets (17), the outer edges of which guide members (17d) project beyond the shorter limbs (20b) of the spreader levers (20), when the latter are in their initial position before the securing of the injectors, nozzles or inlet sockets (17).

10. Apparatus, according to any one of Claims 4 to 9, characterized in that the radially directed force and the axially directed force exerted on or by the spreader levers (20) are determinable by selecting the length of the shorter limbs (20b) of the spreader levers (20).

11. Apparatus, according to Claim 1,characterized in that the spreader discs (22) consist of resilient material.

12. Apparatus, according to Claim 11, characterized in that the spreader discs (22) are constructed as an annular conical shell with inner and outer peripheral slots.

13. Apparatus, according to Claim 12, characterized in that the radial force for sealing the filter tubes (19) and the axial force for the securement thereof are individually determinable by selecting the magnitude of the cone angle a of the spreader discs (22), the elasticity of their material, the thickness of the material, the slot arrangement and the magnitude of the difference between the outer diameter of the spreader discs (22) and the inner diameter of a groove (18b) provided in a split ring (18a).

14. Filtering apparatus substantially as hereinbefore described with reference to, and as illustrated in, Figures 1 to 4 or Figures 1 and 5 to 7, of the accompanying drawings.

14. Apparatus, according to Claim 13,characterized in that at the level of the groove (18b) the split ring (18a) is provided with an inwardly projecting peripheral lip(l8c).

15. Filtering apparatus substantially as hereinbefore described with reference to, and as illustrated in, Figures 1 to 4 or Figures 1 and 5 to 7, of the accompanying dawings.

New claims or amendments to claims filed on 8.5.80 Superseded claims 1 to 15 New or amended claims:

1. Filtering apparatus for dust-laden gas, having a casing (10) and a group offiltertubes (19) which are closed at one end and open at the other end, extend over supporting cages (18) and are fixed in the casing (10) in a tube support base (14) which serves as a partition wall in the casing (10) between the space (15) for the dust-laden gas and the space (16) for the purified gas, the tube support base (14) also having secured therein injectors, nozzles or inlet sockets (17), in which apparatus, when in use, the filter tubes (19) are swept in a direction from the exterior thereof to the interior by the stream of dust-laden gas which is to be purified and, by the aid of the injectors, nozzles or inlet sockets (17), the filter tunes (19)can be, in a periodic sequence, freed from dLst adhering to the external surface of said tubes (1 3) by a stream of scavenging gas directed in counterflow by a scavenging gas device, and in which apparatus said casing (10) is provided with an inlet por (11) for the entry of dust-laden gas into sid dust-laden gas space (15), a port (12) for the exit of purified gas from said purified gas space (16) and means (13) for the extraction of dust, and the filter tubes (19) are sealed in such a mannrto the tube support base (14) by the injectors, nozzles or inlet sockets (17) that no dust can penetrate from the dust-laden gas space (15) into the purified gas space (16) through the sealing surfaces between the filter tubes (19) and the tube support base (14), in which the injectors, nozzles or inlet sockets (17) are secured in the tube support base (14) by means of spreader elements (20 or 22), characterized in that the spreader elements comprise spreader levers (20) or spreader discs (22) which are arranged to snap over out of a stable initial positiqn, which they assume before the securing of the injecors, nozzles or inlet sockets (17) and through an unstable intermediate position during fitting into a stable final position assumed after the securing.

2. Apparatus, according to Claim 1, characterized in that the speader levers (20) and the spreader discs (22) are supported in a split ring (18a).

3. Apparatus according to Claim 1 or Claim 2, characterized in that the spreader levers (20) have an angular cross-section with a shorter limb (20a) and a longer limb (20b).

4. Apparatus, according to any preceding claim, characterized in that the spreader levers (20) are secured to the injectors, nozzles or inlet sockets (17) by means of resilient rings (21).

5. Apparatus, according to Claim 4, characterized in that the resilient rings (21) are constructed as rings of round cross-section material.

6. Apparatus, according to Claims 2 and 3, characterized in that, in the initial position before the securing of the injectors, nozzles or inlet sockets (17) the longer limb (20a) of the spreader levers (20) bears upon the split ring (18a).

7. Apparatus, according to any one of Claims 2 to 6, characterized in that in the secured condition of the inlet sockets (17), a flange (17c) of the inlet sockets (17) bears against the split ring (18a).

8. Apparatus, according to any one of Claims 3 to 7, characterized in that guide members (17d) are provided laterally upon the injectors, nozzles or inlet sockets (17), the outer edges of which guide members (17d) project beyond the shorter limbs (20b) of the spreader levers (20), when the latter are in their initial position before the securing of the injectors, nozzles or inlet sockets (17).

9. Apparatus, according to any one of Claims 3 to 8, characterized in that the radially directed force and the axially directed force exerted on or by the spreader levers (20) are determinable by selecting the length of the shorter limbs (20b) of the spreader levers (20).

10. Apparatus, according to Claim 1, characterized in that the spreader discs (22) consist of resilient material.

11. Apparatus, according to Claim 10, characterized in that the spreader discs (22) are constructed as an annular conical shell with inner and outer peripheral slots.

12. Apparatus, according to Claim 11,characterized in that the radial force for sealing the filter tubes (19) ad the axial force for the securement thereof are individually determinable by selecting the magnitude of the cone angle ct of the spreader discs (22), the elasticity of their material, the thickness of the material, the slot arrangement and the magnitude of the difference between the outer diameter of the spreader discs (22) and the inner diameter of a groove (18b) provided in a split ring (18a).

13. Apparatus, according to Claim 12, characterized in that at the level of the groove (18b) he split ring (18a) is provided with an inwardly projecting peripheral lip (18c).