DE2144446A1 - METHOD AND DEVICE FOR FILTERING AIR OR OTHER GASES LOADED WITH ODOR OR POLLUTANT SUBSTANCES - Google Patents

Description

Collo Rheincollodium Köln GmbH Plant Hersei, 5303 Bornheim-Her sei, Simon-Arzt-Str. 2

Method and device for filtering air or other gases laden with odors or pollutants

The invention relates to a method for filtering with odors or pollutants or the like. laden air or other Gases, the air to be filtered or the like. in contact with a catalytic filter consisting of a redox system is brought. The invention also relates to filter devices that are particularly advantageous for performing the Let procedure use.

To remove gases, vapors, odors, etc. from gaseous media, such as air in particular, are catalytic

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effective filter known, with which a catalytically ^ Implementation of the gaseous substances to be removed can reach normal room temperatures. In this context, a filter has become known in which as a carrier a fine-pored, hydrophilic and open-cell plastic foam is used for a catalytically active redox system in whose cell structure the catalysts of the redox system are built. As a redox system are above all Oxides of polyvalent metals such as manganese, iron, copper, Cobalt, nickel and silver oxide, used in certain combinations. These substances are used together with Sorbing substances, such as activated carbon, the raw foam mixture added in very fine-grained form, so that after foaming has taken place in the cell structure of the foam are firmly and inextricably linked.

Tests have shown that a filter of this last-mentioned type, which is used in the form of webs or plates is used to eradicate odors, especially to remove unpleasant odors and pollutants from the air, e.g. consist of protein decomposition products, can be used with advantage even at room temperatures and that such a filter is superior to the known activated carbon filters in several ways.

It is also already known to use ozone lamps (ultraviolet lamps) to remove unpleasant odors from the air.

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in order to avoid the odorous substances carried along by the air Help of the splitting off when the Cu-MoIeMiIe (ozone) decay to chemically convert active (atomic) oxygen into non-odorous substances. Such ozone lamps are e.g. in kitchen hoods or in other air filters used. It has been shown, however, that the ozone lamps destroy the unpleasant odorous substances The permissible ozone concentrations can only be achieved to a limited extent and that the odorous substances are often only due to the strong Ozone smell are covered. It is also particularly disadvantageous that in closed rooms, such as in cakes, after a certain time to an ozone enrichment of the air can occur, which can lead to a considerable endangerment of the people in the room.

The invention is primarily based on the object of creating a method with which, in particular, in the low Temperature range, especially at room temperature, a compared to the known method can achieve significantly increased effectiveness of air or gas filtering. Farther The invention aims at filter devices, which are particularly advantageous in circulating air and exhaust air systems and above all Have it used wherever it is, e.g. in animal stalls, large kitchens, food processing plants, and cover shops and the like., comes to particularly intense odors and environmental nuisance.

Uas method according to the invention is characterized in that

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that the catalytic filter during the filter operation by supply of active (atomic) oxygen is subjected to an activation treatment.

It has been shown that the effectiveness of the known catalytic filter equipped with an Eedox system are, can be increased to an unexpectedly high degree by the fact that the catalytic substances during the filter operation active, i.e. atomic, oxygen is supplied. This active oxygen benefits not only through immediate Effect on the odorous substances carried by the air when passing through the filter, their splitting and conversion (Oxidation)} it causes in particular a considerable increase in the activity of the catalytic filter by removing the Brings catalysts of the Eedox system to a higher energy level, with the result that the effectiveness of the Eedox system is increased considerably, especially in the low temperature range, and is maintained over a longer period of time. It results Therefore, in addition to a considerable increase in filter efficiency, there is also a considerable increase in filter life. It is also of particular advantage that the active oxygen when the air passes through the catalytic filter is absorbed by this, so that the air leaving the filter is practically free of active oxygen. Any Damage caused by ozone enrichment when using ozone lamps in circulating air systems (kitchen hoods) occur, can therefore occur in the invention

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Do not discontinue proceedings. This also applies when the active oxygen is filtered through ozonization the air is generated by means of an ultraviolet radiator. In this jail the wattage of the ozone lamp and thus the ozone content of the air is set immediately before the catalytic filter so that the filtered air behind the Catalytic filter is practically ozone-free.

On the other hand, the activation of the catalytic filter at the method according to the invention can also be achieved in that the catalytic filter during the filter operation with a solution of an oxidizing agent such as hydrogen peroxide, potassium permanganate, perborate, persulfate and the like., is wetted, preferably sprayed. According to the invention there is also the possibility of using the catalytic filter during The piIter operation intermittently or continuously to move from a filter operating position to a regeneration division and vice versa, with the filter in its Regeneration production is treated with the active oxygen. A device in which the Katalytfilter consists of an endless filter belt, which is moved transversely through the filter space, wherein the Filter activation device outside the filter room is arranged and expediently consists of a bath of a solution of an oxidizing agent, through which the filter belt runs through.

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The method according to the invention can be particularly effective if the catalytic filter is an open-cell, hydrophilic, soft foam, especially polyurethane foam, is used, which serves as a carrier for the catalytic substances of the redox system. The foam expediently has an average pore size of about 0.3 to 4 mm, preferably 0.5 to 1.5 mm. It recommends to put the foam with sorbing substances, such as fine-grained activated carbon in particular. In this case, a filter system is obtained which is due to the interaction of the sorbent substances and the catalysts has particularly favorable filter properties. the catalytically active substances of the redox system and expediently also said sorbent substances are preferred incorporated into the foam, which is achieved by the fact that these substances are finely-grained in the raw foam mixture Form are added so that they are firmly and inseparably integrated into the cell structure of the foam after foaming are. Such filters can be used in the form of sheets, plates, towels and the like. On the other hand, there is but also the possibility of fine-tuning the foam material produced in this way with the incorporated catalysts Process foam flakes, their particle size expediently for the most part below 10 mm, preferably 3 to 5 mm. One such foam flake material can be used as a bulk material filter. In this case, it is advisable to add sorbing substances to the flake material.

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Fe, preferably activated charcoal, to be seen, expediently in one Amount that the proportion of activated carbon in the mixture is 10-40% by volume, preferably 15-25% by volume of the foam volume matters. The activated carbon added to the foam flake material advantageously has a grain size on, which is smaller than the pore size of the foam particles, so that a significant proportion of the activated carbon in the Foam pores is embedded.

In the drawing, exemplary embodiments of the filter devices according to the invention are shown schematically in section.

The filter device according to FIG. 1 has a housing 10 which, on the inlet side, has a funnel-shaped widening Air inlet 11 and the outlet side is provided with an outlet 12 for the filtered air. The housing is on the input side a fan 13. arranged that the air over sucks the inlet 11 and in the direction of the arrow through the filter housing and pushes the filter 14 disposed therein. Immediately in front of the filter 14 in the housing 10 are rod-shaped ultraviolet emitters 15 conventional type arranged, the ozonization of the flowing through the filter housing Cause air.

The filter 14 consists of a porous, air-permeable filter material, which is the carrier for the catalytic active substances of a redox system (combination of different heavy total! oxides). Due to the ozonation of the

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Air is constantly supplied with active (atomic) oxygen to the filter 14 during the filter operation, which is due to decomposition which forms 0, molecules. This atomic oxygen activates the catalysts of the redox system by causing their Oxidation accelerated to the higher level of oxidation. This brings the catalysts to a higher energy level with the result that the activity of the Katalytfilters 14 is increased significantly.

The ozone concentration in front of the catalytic filter 14 is set so that that the filtered air at the filter outlet 12 is practically free of ozone. It is therefore possible to use the device in accordance with Fig. 1 to be used as a circulating air device, e.g. as a kitchen fume ventilation hood, i.e. the filtered air from outlet 12 again returned to the room from which the air is sucked through the inlet 11. Adjusting the ozone concentration on the catalytic filter can be adjusted by setting the wattage accomplish the ozone generator 15 without difficulty. By measuring at the air outlet 12 by means of conventional measuring devices, the setting can be considered for all effect coming applications without difficulty.

It goes without saying that the device shown in FIG. 1 can also be used as an exhaust air device. In this case it will the air sucked in from a room via the inlet 11 after passing through the catalytic filter 14 via the outlet 12 in the outside air is removed.

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The device shown in Mg. 2 corresponds essentially to the device according to FIG But here are 14 spray nozzles directly in front of the catalytic filter 16, which the catalytic filter 14 with the solution of an oxidizing agent, e.g. spray a 5% hydrogen peroxide solution. With help of this oxidizing agent, the catalytic substances of the redox system are therefore constantly oxidized during operation, which also significantly increases the filter activity. The sprayed solution collects in one Collection container 17 below the catalytic filter 14 $ it can be withdrawn from this collection container via the drain 18.

The device shown in Fig. 3, which can also be used in their circulating air or exhaust air systems, has a endless filter belt 20, which is guided around rollers or drums 21. The one with inlet 11 and outlet 12 provided housing 10 is provided between inlet and outlet with housing openings through which the two parallel belt strands 20 'of the endless filter belt pass transversely through the filter housing. The deflection and drive rollers 21 are located outside the filter housing 10 in lateral housing approaches 22. The lower housing extension 22 is equipped with a filter activation device. According to FIG. 3, this consists of a sump or bath 23 of an oxidizing agent, e.g., a hydrogen peroxide solution, through which the filter belt 20 at Circulation is passed around the lower roller 21 so that the

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Catalysts bound to the filter belt, the atomic ones Oxygen of the oxidizing agent and thus oxidized to be activated.

The endless filter belt can move while the filter is in operation 20 move continuously or intermittently. A drive motor can be used to drive the endless filter belt 20 which drives one of the two rollers 21. The air to be filtered flows in while the filter is in operation Direction of the arrow through the two parallel belt strands 20 'of the filter belt, which were previously when passing through, the Bad 23 have been activated. It goes without saying that the tape thickness and bandwidth, the rotational speed and air permeability of the belt as well as the type and amount of the catalysts and activating agent used in each case depend on the particular conditions of use of the device and must be set accordingly.

Instead of the run-through bath 23, however, can also be in the upper and / or lower housing part 22 spray nozzles can be arranged, which the belt 20 with the solution of a suitable oxidizing agent spray.

In the devices described above, an open-pored, hydrophilic, soft one is expediently used as the catalytic filter 14, 20 adjusted foam material, especially polyurethane foam, used, which serves as a carrier for the redox system. As mentioned, they are made of heavy balls,

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Metal hydrates or oxides, such as the oxides of iron, Manganese, cobalt, nickel, copper, silver, etc., existing catalytically active substances advantageously in the Foam foamed so that they are finely distributed are integrated into the foam cell structure. For the catalytic Effectiveness in the low temperature range, it is especially important that the filter is in use has a certain minimum humidity in order to be optimal To ensure the effectiveness of the filter. This moisture can be made available to the filter by the humidity in the air will. An increase in moisture can also be used when using the solution of an oxidizing agent for achieve filter activation.

The proportion of the catalytically active substances foamed into the foam (polyurethane) is expediently approximately 5-15% by weight, preferably 5-10% by weight, based on the Weight of the foam.

In the following some examples of the production of a foam catalytic filter are given, which in the invention Processes with particular advantage can be used:

Example 1;

For the production of a catalytically active, hydrophilic, calibrated and open-cell polyurethane foam 125 parts by weight of a polymeric product made from ethylene

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diamine with propylene oxide and .Ethylenoxid and 125 parts by weight a polypropylene oxide-ethylene oxide mixed product with 25 parts by weight of 10% sulfuric acid neutralized with 50 parts by weight of montmorillonite powder, 15 parts by weight Dehydroaluminosilicate of a molecular sieve, 3 parts by weight of water, 2 parts by weight of tin dioctoate, 9.6 parts by weight of potassium permanganate, 6.9 parts by weight of basic Copper carbonate is added and the mixture is stirred until it is uniformly mixed and adjusted to 20 ° 0.

60 parts by weight are added to this mixture in an intensive mixer Tolylene diisocyanate added until creamy Stirred texture and poured into a coolable vessel. ■ This quickly creates a slightly soft, elastic one Foam, which at about 50 C and one hour residence time in the Drying cabinet is cured.

The polyurethane foam formed in this way, which is considered to be catalytic Active substances Manganese and copper oxide in the finest distribution, integrated in its cell structure, can be used to form plates, foils or filter cloths and in this form as a catalytic filter 14, for example in one of the ones shown in the drawing Filter devices -be installed. When using the catalytic filter in the filter device according to FIG. 3, an endless one becomes Foam tape produced, which forms the carrier for the catalytic substances mentioned. To be adequate To achieve tensile strength of the filter tape, it is recommended to use a foam tape on one or both sides

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to be covered with a porous, tensile base. For example, the foam tape can be applied to an air-permeable endless textile tape. But there is also the possibility of integrating the foam tape with a non-woven layer.
or needled on both sides.

Example 2:

Instead of the polyurethane foam mentioned in Example 1 a foam with the following composition can also be used:

Polyoxypropylene glycol 1

Condensation products of ethylene oxide and propylene oxide with ethylene diamine Sulfuric acid hydrogen peroxide glycerine methylene chloride

Bentonite (finely ground under 50 JLL , preferably under 10 JU) Potash molecular sieve

catalytic ^ substances of the Eedox system, namely:

Manganese Oxide Hydrate Copper-I-Oxide Iron-III-Oxide Hydrate zinc oxide

J-O Weight texle 10 It 0.02 Il 0.04 Il 0.10 It 0.60 Il 3.60 It 1.20 It 1.20 Il

3.60 »

2.40 "

0.70 "

1.20 "

Colylene diisocyanate

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34.66 parts by weight 15.0 parts by weight

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Example $:

The foam mixture of the polyurethane foam mentioned in Example 2 5 - 20, preferably 8-15 parts by weight of activated carbon with a grain size of less than 3 mm are preferred less than 1 mm added, the "during the foaming process together with the other granular additives in the cell structure of the foam is incorporated.

The aforementioned foam catalytic filters can, as mentioned, in the form of webs, giggles, plates and the like in filter recirculation or exhaust air systems. It is it can be assumed that with a filter thickness of 20 mm the filter surface for a filter throughput of 500 up to 1000 nr air per hour is about 1 m.

But there is also the possibility of using the foam mixed with the catalytic substances as a bulk material filter to use. For this purpose, the foam is crushed by means of a flocculation machine and the resulting Foam flakes are then sieved, e.g. on a 10 mm sieve. The sieve passage thus has a particle size below 10 mm on, with the majority of the foam flakes in the range of 2-5 ™. The one obtained in this way Foam flake material is then mixed in a mixer with finely broken up activated carbon, the proportion the added activated charcoal is expediently about 15 - 50% by volume, based on the volume of the unflocculated foam,

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wearing. The grain size of the activated carbon is preferably less than 1 mm, expediently between 50 yU and 1 mm.
The mixture of debris obtained in this way can then be introduced into the filter space of a filter, the height of the bed or the layer thickness of the filter layer being adapted to the particular application of the filter. Since the foam flakes are soft and elastic, the bulk material mixture in the filter space can be compressed to a greater or lesser extent, with the filter resistance being able to be adjusted within relatively wide limits through the hate of compression.

The filter material mentioned in Example 2 or 3 can be
in a flocked fora in a mixture with, for example, the following substances
use:

Example 4t

Flake material according to example 2 or 3
Flake size about 5 Bim, forums size of the foam 0.5 - 1 mm 95% by weight cotton linters, fiber length 5 - 6 mm 5% by weight

Example 5 »

Flake material as in Example 4 50% by weight flake material as in Example 4, but 10 mm

Flake size 45 wt.%

Linen fibers, approx. 40 mm long, 5% by weight

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Example 6 »

Flake material as in Example 4 85% by weight

Alumina with about 15% proportions of gamma corundum structure particles up to 0.5 mm 15% by weight

Example 7t

Flake material as in Example 4 90% by weight

Silica gel, about 1 mm grain size 10% by weight

Example 8:

flake material as in Example 4 85% by weight

Platinum on alumina as a carrier with 0.1% Pt, 2 mm 5% by weight activated carbon up to 2 mm particle size 10% by weight

The fillers mentioned in the examples given above can be used as follows:

Example 9: Kitchen extractor hood

Air volume to be filtered j 200 - 250 mVh

5 liter debris filter

Flake material according to Example 2 with 25% by volume of activated carbon

mixed under 1 mm, thickness of the bulk material filter 30 - 40 mm, two upstream ozone lamps with 15 watt power each

Example 10: Hotel operation, large kitchens, meeting rooms
Required air throughput of the filter: 1000 nr / hour

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Turkey: Pollutant filter, 15-20 liters of flake material as in example 9 mixed with 25 vol.% activated carbon, Filter thickness 40 mm, four ozone lamps with 15 Vatt each

Used to activate the catalytic filter with a solution an oxidizing agent worked, for example an approximately 1% hydrogen peroxide solution or an approximately 0.01 η potassium permanganate solution be used.

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Claims (12)

-ie- 2H4U6 claims 1. Process for filtering substances with odor or pollutants Charged air or other gases, the air to be filtered or the like. in contact with one of a redox system existing catalyst is brought, characterized in that the catalytic filter during the filter operation is subjected to an activation treatment by supplying active oxygen. 2 · The method according to claim 1, characterized in that at the air filtering in the air supply before the catalytic filter Ozone is generated. J. The method according to claim 2, characterized in that the The ozone content of the air upstream of the catalytic filter is set so that the filtered air is downstream of the catalytic filter is essentially ozone free. 4 ·. Method according to claim 1, characterized in that the Catalytic filter during filter operation with a solution of an oxidizing agent, such as hydrogen peroxide in particular, Potassium permanganate, perborate, persulfate, etc., is wetted. 5. The method according to any one of claims 1 to 4-, characterized that the catalytic filter continuously or intermittently from a filter operating position in a - 19 309810/0563 -19- 2U4U6 Kegeneration position and vice versa is moved, with the filter is treated with active oxygen in its regeneration position. 6. Filter device, in particular for performing the method according to one or more of claims 1 to 5, consisting of a catalytic filter which has catalytically active substances of a redox system bound to a carrier, characterized in that the filter device with one of the catalytic filters (14, 20 ) active oxygen supplying filter activation device '(15, 16, 23) is provided. 7. Apparatus according to claim 6, characterized in that in front of the catalytic filter (14) arranged in the airway Ozone generator (15) is arranged. 8. Apparatus according to claim 6, characterized in that in front of the catalytic filter (14) a spray nozzle device (16) is provided with which a solution containing an oxidizing agent can be sprayed onto the catalytic filter (14). 9. Apparatus according to claim 6, characterized in that the catalytic filter consists of an endless filter belt (20), which can be moved transversely through the filter space, the filter activation device (23) being expedient is arranged outside the filter space. 10. Apparatus according to claim 9? characterized in that - 20 - 3098 1 D / Oi -S3 -20- 2H4U6 the activation device (23) from one in the way of the Filter belt (20) lying bath of an oxidizing agent. 11. Device according to one of claims 6 to 10, characterized in that the catalytic filter consists of an open-cell, hydrophilic foam as a carrier material for the catalytic substances of the redox system, the foam having an average pore size of 0.3-4 mm, preferably 0 , 5 - 1 ₅ 5 mm, and is mixed with sorbing substances, such as in particular fine-grained activated carbon. 12. Use of a filter according to one or more of Claims 6 to 11 for the elimination of unpleasant odors caused by protein decomposition products, amines, lower fatty acids, Carbohydrate decomposition products, aldehydes, ketones, acrolein, hydrocarbons, carbon monoxide, organic Sulfur, nitrogen and phosphorus compounds, as well as other pollutants, are effected from the air at low levels Temperatures, especially around room temperature. 309810 / 0S63