JPS60168519A - Filter apparatus for filtering waste gas or water - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (b) Industrial application field INDUSTRIAL APPLICATION This invention is utilized in the field of waste gas and wastewater filtration.

The present invention relates to a filter device for waste gas filtration, in particular for the removal of arsenic, lead, fluorine, blast furnace gas or sulfur oxides from flue gases (in particular porous).
A filter tank filled with filter balls is provided, the tank having an inlet for the fluid to be purified at one end and an outlet at the other tank end, and a transport device for removing the filter balls at one tank end. In addition, a refeed reservoir is provided at the other end of the tank, and a cleaning device is provided in the series of conveying devices for cleaning the filter bulbs.

(b) Prior Art The mode of functioning of this type of filter device is based on the fact that impurities settle by adsorption either on the surface of the spheres or, in the case of porous filter spheres, into the pores. There is.

In the cleaning device these settled impurities are again removed, so that the spheres are fed anew into the circuit and the impurities are filtered out of the waste gas or liquid stream.

This method is obviously only suitable for a few types of impurities, in particular dust, while gaseous impurities, such as sulfur oxides, which arise in the combustion system, can only be captured very incompletely by this method. .

(c) PurposeThe object of the present invention is therefore to construct a filter device of the type mentioned at the outset, which is capable of quantitatively complete filtration of undesirable impurities and, in addition, is selectively adapted to each harmful substance that appears. It is to make it possible to do so.

To solve this problem, according to the invention, an arrangement device is provided for adding a reactant which forms a coating on the filter bulb for harmful waste gas constituents in the region of the refeed end of the vessel. It is located.

B) Construction According to a first embodiment of the invention, such a metering device is constructed with a metering arm arranged as a stirring arm rotatably mounted above or below the surface of the filter bulb; If desired, two such stirring arms can be provided, spaced apart, each serving a different reactant addition role.

Addition of such reactants, such as a mixture of limestone, dolomite, and water, or only water or aqueous ammonia during nitrogen oxide reduction, results in a higher concentration of sulfur oxides, chloride ions, and fluoride ions. Excellent filtration is obtained. The special positioning of the dosing arm below the surface of the filter spheres - approximately 10% below the sphere surface, calculated on the total height of the sphere bank, ensures that the liquid reactants quickly evaporate on the often extremely hot sphere surface. Not only does this have the advantage that it does not perform its function at all or only to a very small extent, but it also has the advantage that uniform agitation of the cleaned balls occurs in the upper region of the ball bag. This makes it possible, in particular, to refeed the entire cross-section of a filter tank configured as a vertical cylinder with fresh, cleaned filter bulbs from above, so that the waste gas flowing convectionally from bottom to top is evenly distributed over the entire cross-section. You can get purification.

Waste gases that are particularly highly contaminated with harmful substances, especially if the waste gas contains many different harmful substances, can be further developed following the stirring arm according to the invention, i.e. in the case of a vertical filter tank. Advantageously, the device is provided with a second addition device arranged further below, which can optionally constitute a second stirring arm.

It has proven particularly advantageous if the end to which the purified filter spheres are fed back in is provided with a combustion-active catalytic process and/or with an addition device for fragmented limestone or dolomite into the bulk powder. became.

Limestone or dolomite, which is supplied in spherical or naturally crushed form, may be present at 10% in the bulk powder mixture alongside the usual filter spheres, for example, and slides down with the filter spheres.

The layer formed on the surface by reaction with 802 is washed off at the lower end, where the mixture of filter spheres and limestone or dolomite fragments is exited through the transport device, or at a subsequent point within the frame of the transport device. Therefore, after refeeding, a new limestone surface is used for a new reaction with the filtered impurities.

Another desirable reactant is calcium or magnesium chloride for improved fines separation.

These substances are hygroscopic and trap dust with a viscous surface layer, which after drying is in the form of a salt crust and can be removed again without problems during the filter pack purification process.

With the addition of reactants according to the invention, other materials can also be used as porcelain for filter processes, such as the much cheaper expanded clay process or similar porous and adsorption capable materials. The filling of the filter layer is then carried out, for example, during dedusting from an expanded clay process with a surface of calcium chloride or magnesium chloride, and 90% expanded clay process and approximately -10% limestone or dolomite particles (crushed stone 8
．． ! During the purification of the gaseous constituents from the mixture (-30), additional reactants can still be fed onto the stirring arm as already mentioned above.

Purification of the exhaust gas from nitrogen oxides is particularly possible when the filter device is configured with two stirring arms arranged one above the other. In this case, the lower stirring arm feeds water containing, for example, ammonia, while the upper stirring arm dispenses a solution of chromium, molybdenum or copper, or a mixture of these substances into the filter bulb. These solutions act as catalysts and are very active in the removal of nitrogen oxides.

During waste gas purification of flammable vapors, a combustion-active catalyst can be mixed under the bulb, and then the flammable vapors are immediately combusted, or alternatively the bulb is washed at the lower end and sent to the top of the device. It is conveyed to a combustion chamber where it is either regenerated again by relatively high temperature combustion gases or additionally combusted.

For a series of applications, however, during the distribution of the reactants with the aid of a stirring arm in the surface area of the filter sphere pack, difficulties may arise with an even layering of all filter spheres over the entire cross section of the filter vessel. It became clear. Due to the close packing of filter spheres, there is no longer a spray cone that ensures that a coating layer can be applied around practically all spheres. However, this also means that at individual locations the flue gas flows past the filter bulbs, which are not stratified and therefore have no effect on waste gas detoxification. Very fluid and less sticky reactants run the risk of being carried away by the waste gas stream before the reactants reach the top of the filter bulb. However, this in itself means that the purified gas is now artificially contaminated with reactants and must be purified once again.

In order to eliminate these difficulties, a further development of the invention provides that the metering device is arranged outside the filter vessel and that the filter bulbs are provided with a specific coating layer when they enter the filter vessel, so that the flowing flue gas is This prevents excess reactants from being carried away.

In this case it is important not only for the effect of the reactant layer on the sphere that the reactant layer has a certain minimum thickness, but also that this layer does not exceed a certain maximum thickness. This assumes the recognition that it is important. This is because the loading of the flue gas with the reactants that would otherwise be carried away by the flue gas partially reenhances the desired purification effect, or quite the contrary.

In a further development of the invention, it can be provided that the dosing device has a spray device for the reactant, which is arranged above the inclined track for the filter sphere, which is designed in part as a grid. The purified filter sphere is placed on an inclined track,
The reactant is sprayed during rolling down, and at this time, due to rolling on the one hand and lattice formation on the other hand, the entire surface of each method is coated with the reactant, and the coating layer is not generous, and the excess material, This ensures that the reactants can flow out and then be returned to the reactant storage tank. By arranging a relatively long drying section - depending on what kind of reactant is used - it is possible to ensure that the coating layer hardens further before the filter spheres enter the filter container.

A particularly simple construction of the construction of such an arrangement, as envisaged in another feature of the invention, is to arrange the dosing device above the filter tank, so that the newly stratified filter spheres are fed from above. A gas-permeable collection hopper is provided above the removal device for the filtration process, which can slide into the filter container, preferably at the lower end, and forms an internal bottom at the lower end of the filter container.

The simple sliding of the filter bulbs from the dosing device eliminates the need for special conveying devices and allows a particularly advantageous adjustment of the coating thickness or the simple drying of the coating layer. Such drying, or at least partial drying, is suitable, for example, when a lime solution is attached to a filter bulb for desulphurization.

As an advantage of the flow of flue gas through the filter tank in the same direction as the descent of the filter bulb, the risk of entrainment of reactants by the flue gas is further reduced. If the flue gas convects, which is in principle possible, even if a coating layer according to the invention has been placed beforehand, there is still a high risk of carrying away the reactants. This is especially the case since the flue gases appear above the stratified filter bulb at a high temperature, and the stratification is still at a stage where it is new and can therefore be carried away very easily below. However, even in such a co-directional passage of filter spheres and flue gas through the filter tank, the adjustment of the quantity and sphere stratification according to the invention is of great importance. This is because excess reactants can still be carried away even with such a co-directional passage of the purified flue gas. Not only filter bulb puncture adhesion,
This is because there is therefore additional blockage and obstruction of the flue gas flow.

The removal device can be followed by a cleaning device including a filter ball conveying screw, which can be designed as an almost horizontal and possibly slightly ascending tube in the conveying direction, from which the cleaning liquid is subsequently supplied to the reprocessing facility. Ru.

In this case, an intermediate storage for the cleaned filter bulbs is arranged later in the cleaning device for the filter method, and stagnation and obstructions somewhere in the filter device lead to a complete blockage of the filter bulb supply or to the entire installation. It has become clear that it is appropriate to completely eliminate the occurrence of stagnation, which may even cause damage.

Depending on the specific impurity, different anti-core materials may be provided in the filter sphere. Optionally, several stations can be provided, each with a filter device for a different reactant, so that each harmful substance can be filtered out in turn. In the case of particularly important desulphurization of flue gases, a further configuration of the device according to the invention includes a mixing device for creating an aqueous solution which is fed to the atomization device through a metering device, a drying section, connected to a lime or limestone silo. It is characterized by an extension of the inclined run in the spray equipment train, which acts as a spray system, as well as a bulkhead water purifier, arranged in the reprocessing equipment train, for the separation of solid impurities, including in particular gypsum, from the wash liquor.

The gypsum is discharged, while the purified cleaning liquid is returned to the cleaning device again, optionally with the addition of fresh water and alkaline solution. In bulkhead water purifiers, the cleaning liquid is treated with a flocculant to separate impurities, especially gypsum in the case of quasi-desulfurization.

The filter device according to the invention with filter bulbs that are each continuously circulated and purified again is also highly suitable for the purification of liquids, especially oil-contaminated water.

In this case, the adsorbingly active filter spheres, which adsorb oil with their surface layer, are transported into a purification layer placed above the filling container, and after the oil has been removed from them, they fall through a metering device into the filter container. It became clear that it was particularly appropriate to return.

In this case, thermal decomposition or combustion of the absorbed harmful substances takes place in the septic tank, and in the case of purifying seawater contaminated with dust, for example, a combustion tank is first fed by a transport device directly above the fill container. A pyrolysis tank is placed above it, into which filter spheres impregnated with oil are first dropped. During thermal decomposition of oil, benzine and light oil are produced.
A separator separates it from the pyrolysis gas, while a layer of coke forms on top of the foil spheres. The pyrolysis gases are partially combusted through the calorific value device and recycled for use in maintaining the pyrolysis. The filter spheres with a layer of coke fall through a metering flap or the like into the septic tank below, where the coke layer is burned off, so that at the bottom a completely purified filler sphere is discharged - again through the corresponding metering device. The seawater is returned to its original filling container where it flows from the bottom to the top.

The purification of the filter bulb in a septic tank placed above the actual filter vessel is not only suitable for the purification of oil-contaminated waters such as those mentioned above, e.g. seawater, but also for cleaning flue gases and other emissions. Other advantages of the invention include: Features and details will become apparent from the following description by means of some exemplary embodiments and the drawings.

Figure 1 shows a schematic cross-sectional view of a waste gas filtering device with a stirring arm, Figure 2 shows a schematic diagram of the structure of the equipment with external treatment of the filter bulb and its stratification. This also shows a schematic diagram of the device for purification.

The waste gas filtration system shown in FIG.
The device described in an earlier application (German patent application P814
0655.3), parts having the same reference numerals as parts described therein will no longer be described in detail hereinafter.

What is new in the waste gas installation according to the invention is the provision of two stirring arm systems 80, 81, one above the other, which in the illustrated embodiment are arranged in a particularly simple manner on the drive shaft 23 of the screw conveyor 18. It is hung on the shaft and rotates with the moving shaft. A hollow stirring arm provided with a liquid outlet 29 or 32 is fed with a specific reactant through a feed pipe 33 or 34, for example a solution of chromium, molybdenum or copper or a mixture of these substances into the stirring arm 31 through a pipe 33. is sent for catalytic removal of nitrogen oxides. Correspondingly, aqueous ammonia is supplied to the stirring arm 30 through the pipe 34. Stirring arm system 80,3
1 are both below the surface of the filter sphere bag, so that the reactants do not ineffectively evaporate on the heated surface of the sphere pack. In this way, not only is a stirring effect produced, resulting in an even mixing and therefore an even purification of the effluent flowing from below over the entire cross section of the filter tank I.

35 are provided with combustion-active catalyst spheres and /''1 or a dosing device for fragmented limestone or dolomite.A feed pipe, only shown in outline, runs near the upper end of pipe 19 fed by a screw conveyor 18. To pass through, the catalyst spheres or limestone or dolomite pieces fall into the upper end of the tube and are thrown out evenly by the screw together with the purified filter spheres, and finally from top to bottom with the help of the upper stirring arm stem 30. It is mixed into the filter ball pack that slowly slides down.

The core of the preferred embodiment according to the invention of the waste gas purification device according to FIG. Ball 2 is filled. In 3a there can be seen an inlet opening for the waste gas reservoir to be purified, in the illustrated embodiment the flue gas to be desulfurized, which joins above the pack of the filter tank 1, while in 3b At the lower end of the filter tank l, a discharge pipe for collecting purified flue gas is arranged.

A gas-permeable hopper 50 forming the internal bottom collects the filter balls 2 sliding down one after another from top to bottom and leads them to a removal device to which a filter ball cleaning device 52 is connected. The filter bulbs 2, which are constantly being added to the filter pack in the filter tank l and filled from above, are loaded with reactants in a series of first dosing devices, which will be explained in more detail below, and the inlet pipe 3a It absorbs the harmful components of the flue gas that are to be separated out, respectively, while this flue gas flows through the filter vessel 1 from top to bottom in the same flow as the downward movement of the filter bulb.

The impurities then combine with the reactants and therefore stick firmly to the filter bulb. Not only does this result in an excellent additional filtering effect of the still somewhat moist reactants, but also of dust-like impurities that are still present. The cleaning device 52, in the illustrated embodiment, comprises a primarily horizontally arranged pipe 53 and a screw conveyor 54 for the filter bulbs, which conveys the filter bulbs with the cleaning liquid in an intermediate tank for the cleaned filter bulbs in countercurrent flow. 55. The cleaning liquid is sent in the region of the discharge end to an intermediate storage tank 55, which in the case of flue gas desulphurization is washing soda. By slightly raising the tube 53 in the conveying direction of the screw 54 as necessary, the cleaning liquid can flow through the tube in a countercurrent flow to the filter bulb, and is supplied to the bulkhead water purifier 57 through the tube 56. A condensing agent is mixed into this from the container 58, and impurities are separated from the cleaning liquid.

In the case of flue gas desulphurization, specifically considered here - gypsum is produced primarily, apart from additional dust-like impurities,
This is collected in the bulkhead water purifier 57 and transported through the screw device 59 into the transport silo 60. The purified cleaning liquid passes through a pipe 61 to a clarification water tank comprising an alkaline liquid storage tank 62, from where it is finally returned again through a pipe 63 to the inlet of the cleaning device.

The purified filter balls are fed by a lifting conveyor 64 to a percussion device 65, which has an inclined track 66, configured at least partially as a grid, over which the filter balls roll down. As it rolls down, the filter bulb is sprayed by a spray device 67 with a reactive fluid, in this case lime solution. The excess lime solution immediately flows out through the grate again and is discharged through a tube 68, only shown in outline, into the lime solution. of(
(generally of reactants) is again fed into the metering device 69.

The inclined track 66 is of such an extent that the lime solution can at least partially dry in a thin layer, after which the layered filter spheres are introduced into the upper filter tank l and distributed there by a distribution device, for example a deflector 70. , the filter spheres are layered as evenly as possible on the surface of the filter pack in the filter bath l. 71 represents a lime or limestone silo, from which the lime or limestone is supplied via a conveying device 72 to a mixing device 73 for producing an aqueous solution. This aqueous solution is finally fed via a metering device 69 to a discharge device.

74 and 75 show the outline of the supply pipes for the new additional water.

Although the invention is limited to the embodiment shown in FIG. 2, it is of course possible for the removal device for layering the filter spheres to be constructed in a different way. However, it is important in this case that, on the one hand, a certain minimum thickness of the applied layer is obtained, evenly over the entire spherical surface, and, on the other hand, that if the layer becomes too thick, this excess reactant is removed by the flue gas into pure gas. The layering of the filter layer is such that it is avoided that the layer is too thick so that it cannot contaminate and be carried away. Furthermore, the device according to the invention is not only suitable for the desulphurization of flue gases by supplying lime solution, but can also be equipped with other reactants, in particular for the removal of corresponding further pollutants. Filter from the gas stream.

In the seawater purification equipment shown in FIG. 3, a combustion tank 36 is arranged above the filter container 1, and a pyrolysis tank 37 is arranged above the combustion tank 36. The filter sphere, which is conveyed upward by the transport screw 18 at the lower end of the filter container, removes oil contamination from the seawater by adsorption, so that the contaminated seawater that entered at 38 can be taken out again as clean seawater at the upper end 39.
With the aid of a transport device, it is transported through the combustion tank 36 to the upper end of the pyrolysis tank 37. In this pyrolysis tank, pyrolysis of the oil component takes place, thereby forming sibenzine, light oil and pyrolysis gas, which exit at 40 and first pass through a heat exchanger 41 . At this time, the pyrolysis gas is separated from benzene or light oil also generated during pyrolysis. These are separated from the water component in a separator 42. A portion of the pyrolysis gas is fed back into the pyrolysis tank at the lower end 45 through pipe 43 and combustion value device 44 to maintain pyrolysis. During pyrolysis, a layer of coke forms on the filter spheres, and the spheres fall with this coke layer from above through a metering flap or the like into the top of the combustion tank. Combustion of these coke components takes place here, air is supplied at the lower end 46, while combustion air is taken off at the upper end 47, in the heat exchanger 48 of the combustion value device 44 and in the air supply section of the pyrolysis tank. 48 and a heat exchanger in the air supply section 49 of the combustion tank, it is finally led to the chimney as waste gas. In this way, the required combustion gas is also always preheated and supplied to both the combustion and pyrolysis tanks, in order to ensure complete pyrolysis and combustion in all areas of each stage. It's advantageous. Finally, the filter spheres, completely purified by the combustion of the coke layer, fall again through the corresponding metering device between the combustion tank 36 and the filter tank l into the upper filter tank l, where they are once again freed from seawater. Used for adsorption and removal of oil contamination.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional diagram of an exhaust gas filter device with a stirring arm, Fig. 2 is a structural diagram of the equipment with external treatment of the filter bulb and its stratification, and Fig. 3 is a schematic diagram for purifying oil-contaminated seawater. FIG. 1 is a filter tank, 2 is a filter bulb, 30 and 31 are stirring arms, 35 is an addition device, 36 and 37 are septic tanks, 50 is a hopper, 51 is an unloading device, 52 is a cleaning device, 55 is a storage tank, and 57 is purified water 65 is a dispensing device, 66 is an inclined running track, 6
7 is a spraying device, 71 is a silo, and 73 is a mixing device. Patent applicant procedural amendment form ω), @,, 59□2 patent application, JI Yu2374042,
Invention 0 Name IQ, f, X, t if U to filter water
3 Relationship with the case of the person making the amendment Patent applicant

Claims (1)

[Claims] (1) A filter device, especially a porous filter, for waste gas filtration, especially for removing arsenic, lead, fluorine, blast furnace gas or sulfur oxides from flue gas. A filter tank filled with bulbs is provided, the tank having an inlet for the fluid to be purified at one tank end and an outlet at the other tank end, and a transport device for the filter bulb removal tank at one tank end. , for refeeding at the other end of the tank, and a cleaning device arranged in the series of transport devices for cleaning the filter bulbs, which is not harmful to the area of the refeeding end of the tank. A filter device, characterized in that an arrangement device is arranged for the addition of a reactant which forms a coating on the filter bulb for the exhaust gas components. (2) A device 35 for adding combustion-active catalyst balls and/or fragmented limestone or dolomite into the bulk powder is provided at the end of the tank where the purified filter balls are fed again. Filter device 0 according to claim 1 (3) Claim 1 or 2, characterized in that the filter spheres 2 are at least partially expanded clay spheres.
The filter device described in section. 4) The filter device according to any one of claims 1 to 3, wherein the filter sphere 2 is a ceramic sphere. (5) The filter device according to any one of claims 1 to 4, characterized by a device for adding pyrolytic substances for capturing fine dust particles on the sticky surface layer on the filter sphere. . (6) The metering device comprises a positioning arm arranged as a stirring arm 30 rotatably mounted above or below the filter bulb surface.
The filter device according to any one of Items 1 to 5. (7) The filter device according to claim 6, characterized in that there is a second addition device following the stirring arm 30 and optionally constructed as a second stirring arm 31 . (8) the metering device 65 is arranged outside the filter tank l;
From claim 1, characterized in that the filter bulb is provided with a specific coating layer when it enters the filter vessel 1, so that the flowing flue gas cannot carry away excess reactants. The filter device according to any of the items up to item 5. (9) The metering device 65 is provided with a spray device 67 for the reactant which is arranged for the filter spheres above the inclined track 66 which is at least partially constructed as a grid. A filter device according to scope 8. The QO metering device 65 is arranged above the filter vessel 1, so that the purified and freshly stratified filter bulbs slide from above into the filter vessel l, through which the flue gases preferably flow from top to bottom. The filter tank 1
According to claim 8 or 9, a gas-permeable collection hopper 50 forming an internal bottom at the lower end of the filter bulb is provided above the removal device 51 for the filter bulbs. filter device. 01) A patent characterized in that a cleaning device 52 including a filter bulb conveying screw is connected after the unloading device 51, the cleaning liquid is sent in the opposite direction to the conveying direction, and a cleaning liquid reprocessing facility is provided. Claims 8 to 10
A filter device according to any of the preceding paragraphs. 12. A filter device according to claim 8, characterized in that there is an intermediate storage tank 55 for cleaned filter bulb sump following the filter bulb sump cleaning device 52. 03 A mixing device 73 connected to a lime or limestone silo 71 for producing an aqueous solution which is fed through a metering device 69 to a spraying device 67, an inclined track 66 serving as a drying section
extension, as well as a sump for desulfurizing flue gas by lime or limestone, characterized by a bulkhead water purifier 57 for separating the washing liquid from solid impurities, in particular gypsum, arranged in the course of the reprocessing facility. , a filter device according to any one of claims 8 to 12. α → A filter device for the purification of liquids, especially oil-contaminated water, comprising a filter tank filled with porous filter spheres, which has an inlet for the fluid to be purified at one end of the tank; Filter bulb purification with an outlet at the other tank end, a transport device for removing the filter bulbs at one tank end, a transport device for refeeding the reservoir at the other tank end, and arranged in a series of transport devices. The filter bulbs with adsorption activity are transported into the septic tank (86, 37) arranged above the filter tank 1, and from there are added into the filter tank 1 through a metering device. Filter device 〇αυ septic tank (86
, 87), wherein the thermal decomposition or combustion of the harmful substances adsorbed is carried out.
Filter device as described in section.