FR2489168A1 - Gas filter which can be regenerated - has fibrous filter packing, which is stretched and vibrated to remove solid particles (AT 15.1.82) - Google Patents

Abstract

The filter consists of a vertical ring cylinder contg. a vertical stack of funnel-shaped partitions dividing the cylinder into several zones. A slotted axial tube feeds a gas to be purified into the zones. Each zone contains a pair of funnel-shaped grids supporting a fibrous filter packing. In the axial tube is a vertical rod with arms passing through the inclined gas inlet slots; and the arms support the lower grid in each pair of grids. When the filter requires regeneration, the rod is lowered so the filter fibres are stretched between each pair of grids. The rod is pref. fitted with a vibrator, so the solid particles trapped by the filter fall off into a bottom hopper. High efficiency purificn. of large vols. of gas, and simple regeneration is achieved.

Description

IMPROVED FILTER
The present invention relates to devices intended preferably for purifying gases, and more specifically relates to filtration devices also designated below by filters.

 The devices according to the present invention find an outlet in the metallurgical, cement, chemical, mining, food and other industries, and are used in particular in these industries for purifying gases and purifying air.

 Currently, there is a rapid increase in all countries in the production plants using pulverulent materials, which during the treatment process give rise to pollution of the ambient environment due to dust. To purify gases and liquids, it is necessary to have filters with high efficiency, easy to maintain and to regenerate, inexpensive and allowing to obtain a high purification efficiency.

 Currently in the industry, filtration devices of very different constructions are used.

Thus there are known filtration devices comprising a body, filter sleeves formed of woven materials or wool fibers arranged in vertical rows and parallel to the walls of the body, a regeneration mechanism and a dust collector. The gas to be purified passes through the walls of the sleeves, the dust being retained by these walls which allow the pure gas to pass (cf. for example, French patent application N0 2012540).

To regenerate the filter, shake the sleeves and blow in compressed air.

 The disadvantages of filters of this type lie in their large dimensions, their high resistance, their difficult regeneration and the short service life of the handles. During regeneration, the sleeves indeed wear a lot, especially in their lower part, which leads to their rupture and makes them unusable.

 Filtration devices are known (cf. for exampleg the certificate of inventor of the USSR NO 511962), comprising a cylindrical body inside which is disposed a grid from which fibers are suspended, and a chamber elastic attached to the inner wall of the body at the level of the fibers. The gas to be purified is brought under pressure into the elastic chamber, and the fibers, by tightening, form a filtering layer through which the medium to be purified passes.

To regenerate the fibers, the pressure in the elastic chamber is reduced, which causes the fibers to be released, and then washed.

 The drawback of this type of filtration device lies in the complexity of the regeneration operations, in the low yield, in the insufficient resistance of the Glastiqu @ D chamber as well as in the low purification efficiency which is in particular due to slipping. of the medium to be purified in the folds which form in the walls of the elastic chamber.

 There is also known a filtration device (cf. for example, the inventor's certificate of 1 "URUS% N 417145), comprising two discs between the outer edges of which the wire elements are stretched.

 brings between the discs a dirty medium which is purified in the layer of taut filiform elements. To regenerate the filter, circulate a fluid in the opposite direction.

 The disadvantage of this filter resides in the purification of the liquid which is insufficiently effective due to the lack of adhesion of the elements to each other, and in the excessive consumption of the liquid used for washing, the latter being ineffective.

 A filter is known (cf. for example, the patent of the German Federal Republic N0 1435296)> which comprises a cylindrical body provided with a cover in which is placed a bag made of a porous material. Inside this bag is an elastic membrane of cylindrical shape, which is inflated by a pressurized fluid, which establishes a pressure in the medium to be purified introduced between the bag and the membrane. The medium to be purified crosses the pores of the bag, while the deposit remains on the walls. In order to carry out the regeneration, the cover is lifted and the deposit is separated from the surface of the bag.

 The disadvantage of filters of the latter type consists in the complexity of the regeneration and in the small volume of the filter material, which requires frequent cleaning of the bag.

 A filter is also known (cf. for example, the USSR inventor's certificate No. 323134)> comprising a body provided with gas supply and discharge pipes, and a hopper located in the lower part of said body. Inside this body are arranged a tube and perforating grids in the form of funnels, which are provided with an elastic seal arranged along their edges in contact with the body. Between the grids is placed a fibrous lining. To perform the regeneration, the grids are removed from the body and the fibrous material is removed from the deposit by hand or by washing.

 The disadvantage of this filter lies in its low efficiency, in the need to dismantle the filter to regenerate it and to replace the lining, and also in a large consumption of filter material due to the service life of the latter.

 The object of the present invention is to eliminate the above-mentioned drawbacks.

 The invention aims to achieve a filter, allowing an increase in the purification efficiency of a large volume of gas with a high purification efficiency, a convenient regeneration and a good purification of the lining during this regeneration, with large time intervals between successive regenerations thanks to a modification of the production of the filtering lining.

 According to the invention, the filter, comprising a vertical body provided with gas supply and discharge pipes, a tube arranged coaxially inside said body and surrounds perforated grids in the form of a funnel, a filtering lining housed inside each pair of perforated grids, and a hopper arranged in the lower part of the body, is characterized by partitions arranged between each pair of perforated grids and their lining and divides the body into sections, inclined lights being provided in said tube opposite each section.

 Such an embodiment of the filter allows the purification of large volumes of gas with a high purification efficiency, which is achieved by the use, as filtering layer, of fibrous materials having a large filtration surface, arranged in several stages . In addition, the filter occupies a small area, thanks to the increase in its height.

 Advantageously, a rod is molded inside the tube, coaxial with the latter, so as to be able to rotate and move axially, this rod being provided, at each inclined lumen, with arms passing through these lumens and are connected to the lower grid of each pair of perforated grids, in each of the sections.

 It is thus possible to control both the filtration and regulation processes thanks to the fact that the rod is connected to all the grids, the control mechanism being located outside the filter. The rotary movement of the rod ensures the arrangement of the lining threads in the same direction, which makes it possible to avoid the formation of gaps which reduce the gas cleaning efficiency.

 Preferably, the rod arranged in the tube is associated with a source of vibration, for example, a vibrator, this rod comprising a vertical displacement control.

 It is thus possible to adjust the compression ratio of the lining by vertical displacement of the rod carrying the lower grids and to subject the lining to vibrations during regeneration by activating the source of vibrations.

 Advantageously, as lining, wires are used, the ends of which are connected to wire carriers fixed on the perforated grids in the form of a funnel.

 Such an embodiment makes it possible to stretch all the wires of the lining by spacing the grids of a pair and to arrange said wires in rows between which games or spaces are formed. The deposit is evacuated through these clearances during the vibration of the lining.

 Advantageously, the wire holders are produced in the form of concentric rings arranged coaxially with respect to the body.

 It is also possible to distribute all the wires uniformly according to the filtration surface and to avoid local leaks reducing the efficiency of the treatment.

 In the case of filters having particularly large dimensions, the wire carriers are advantageously produced in the form of plates fixed radially to the grids in the form of a funnel.

 This gives easy access to the rows of wires for their inspection and repair, through windows made in the side walls of the body, which is particularly important for the construction of large diameter filters.

Other objects and advantages of the invention will appear on reading the following description and the figures corresponding to exemplary embodiments given without limitation;
Figure 1 shows a vertical section of the filter (in the two upper sections is shown a period of operation of the filter according to the filtration regime, while in the lower section is shown a period of operation according to the regeneration regime);
Figure 2 is a vertical section of the central tube at the middle section of the embodiment of Figure 1;
Figure 3 shows a vertical section of the central tube at the upper section of the embodiment of Figure 1;
Figure 4 shows a radial section of a portion of the lower perforated grid in the shape of a funnel;
Figure 5 is a section of the embodiment of Figure 1, in the case where the son carriers are made in the form of annular concentric plates;
Figure 6 is a section similar to that of Figure 5, but in which the son carriers are made in the form of plates arranged radially in the perforated grids funnel-shaped.

 The filter according to the invention, in the embodiment described and shown, comprises a vertical ferrule or body 1 (Figure 1), of annular cylindrical shape, provided with a hopper 2 in its lower part and a cover 3 in its upper part, as well as supply pipes 4. Inside the vertical shroud 1 is arranged coaxially and along its entire height from the cover 3 to the hopper 2, a tube 5 whose end upper is connected to the inlet pipes 4 and the lower end of which opens into the hopper 2. The vertical ferrule 1 is also provided with discharge pipes 6.

 The tube 5 is rigidly fixed to the vertical ferrule 1 by inclined partitions 7 each having the shape of a funnel, produced from a plate of an appropriate material (for example, from a sheet of 'steel). The partitions 7 in the form of a funnel are arranged along the height of the vertical body 1 preferably at the same distance from each other so that the space between the vertical ferrule 1 and the tube 5 is divided into equal sections 8 of which the lower and upper walls are formed by the partitions 7 in the form of a funnel and the intermediate side walls by the part of the ferrule 1 and corresponding tube 5. In the lowest part of each section 8 is formed in the tube 5 an opening 9 of annular shape connecting the interior space of the tube 5 to the interior space of each section 8. The openings 9 can be made continuously over any the circumference of the tube 5 (as shown in Figure 2) or even be associated with spacers 10 (Figure 3), which make the tubes 5 more rigid.

From each opening 9 go upward the inclined lights 11 (Figure] 2, 3) formed in the body of the tube 5 and all having the same inclination relative to the generator of the tube 5. All the lights 11 are inclined in the same direction.

 Inside each section 8 (Figure 1) are arranged upper and lower inclined grids 12 and 13 forming funnels, the dimensions of which are chosen so that each of them slides by one of its edges on the inner wall of the ferrule 1 and by its other edge, on the outer wall of the tube 5, each of the perforated grids 12, 13 comprises rings 14 (FIG. 4, 5) produced, for example9 in the form of annular coaxial tubes on which combs are fixed 15 having notches 16 (Figure 4) in which are housed wire holders 17 (Figure 4, 5). These son carriers 17 are made in the form of concentric annular plates and separated from each other by a clearance 18. The son carriers 17 are retained in the comb 15 by means of a pin 19 (Figure 4), which is fixed using a shackle 20 with a comb 15.

 Between the upper and lower grids 12 and 13 (Figure 1) is arranged a filtering lining 21 made in the form of insulated wires 22 fixed by their ends to the wire carriers 17 (Figure 4) of the grids 12 and 13 (Figure 1) so to form straight vertical lines arranged in cylindrical rows 23 (Figure 4) 9 the son 22 constituting the generatrices of these cylinders.

Each upper grid 12 (Figure 1) is fixed to the upper part of the corresponding section 8 by means of springs 24 while each lower grid 13 is connected by arms 25 (Figure 1, 4) to a rod 26 placed coaxially in the tube 5 so as to be able to rotate and move in the axial direction;
The arms 25 are connected by one of their ends to the rings 14 (Figure 4) of the lower grid 13 (Figure 13 and by the other end to the rod 26.

 The middle part of these arms 25 is slidably engaged in the inclined readings 11.

The rod 26 is connected to a source of vibrations 27 and to a control 28 intended to allow the displacement of this rod in the vertical direction
The filter according to the invention operates as follows:
A polluted medium is introduced, via the inlet pipes 4 (FIG. 1) into the pipe 5 and through the openings 9 in the sections 8. Part of the particles then moves by inertia downwards and enters the hopper 2 .

 The medium to be purified then reaches the grids 12 and 13 and the filtering lining 21 clamped between these grids, the medium is purified by passing through this filtering lining and is evacuated by the evacuation pipes 6. As soon as the filtering lining is clogged by the deposited materials> an order of regeneration is issued. Following this order, the rod displacement control 28 causes the rod 27 and the lower grids 13 to descend, the wires 22 of the lining 21 becoming elongated and spaces forming between their rows.

A series of concentrically arranged cylinders is thus obtained, formed by the wires 22. The vibration source 27 then starts up and the deposit accumulated between the wires 22 and inside these wires falls on the partitions 7, and s then flows by following the inclined surface of the partitions 7 and the openings 9, in the tube 5 and in the hopper 2.

 Regeneration can also be carried out without resorting to vibrations and, in particular by rapidly dropping the grids 13 after having released the rod 26 from the control 28 for moving this rod. After the regeneration, the rod 26 and the lower grids 13 are brought up by means of the rod displacement control 28.

The arms 25, by sliding in the inclined openings 11 rotate the lower grids 13 around their axes.

In this way, the wires 22 of the lining 21 are placed in an orderly manner and are clamped between the grids 12 and 13. This avoids the formation of significant gaps between the wires 22, as would be possible during a messy placement.

 In order to allow replacement and repair of the lining 21 (Figure in the small diameter filters, the vertical shroud 1 consists of several removable sections 8. In addition, in large diameter filters, it is recommended to practice in all sections 8 of the shell 1 of the holes (not shown in the figures) through which the inspections and repairs of the lining 21 are carried out. Advantageously, the wire carriers 17 (FIG. 6) are produced in the form of plates and fixes them in the grids in a radial way.With such a construction, access to 22 used wires and their replacement becomes easier (Figure 1).

 The threads 22 used in the filter according to the invention can be made from various materials (lavsan, caprone, wool, cotton, silon, fiberglass, metal etc.) having different diameters and twists to obtain forms of fibers varied.

 In addition, different combinations of these various materials can be used.

 Of course, the present invention is in no way limited to the embodiments described and shown; it is susceptible of numerous variants accessible to those skilled in the art, depending on the applications envisaged and without departing from the spirit of the invention.

Claims (7)

 1.- Filter comprising a vertical body provided with gas inlet and outlet pipes, a tube arranged coaxially inside this body and in the form of perforated grids in the form of a funnel, a filtering lining rises to the interior of each pair of said perforated grids and a hopper disposed in the lower part of the body, characterized in that it is provided with funnel-shaped partitions disposed between each pair of perforated grids 1? -1f with their lining , dividing the body into sections, inclined apertures 11 being formed in said tube opposite each section 8.  2.- Filter according to claim 1, characterized in that a rod is arranged coaxially inside the tube, so as to be able to rotate and move axially, this rod being provided at each inclined lumen with arms which pass through these lights and are connected to the lower perforated grid of each pair of grids, in each section 8.  3.- Filter according to claim 2, it is in that the rod is associated with a source of vibration 27.  4.- Filter according to claim 2, c a r a c t é r i s in that the rod is associated with a control intended for its movement.  5.- Filter according to claim 1, c a r a c t é r i s in that as filtering lining, are arranged son whose ends are connected to son carriers fixed on the perforated grids.  6.- Filter according to claim 5, c a r a c t é r i s in that the son carriers are made in the form of concentric rings arranged coaxially in the body.  7.- Filter according to claim 5, c # r a c t é r i sé in that the son carriers are made in the form of plates fixed to the perforated grids.