EP0805915B1 - Device for removing substances in gas and vapour form in a stream of exhaust air - Google Patents

Abstract

In a device for removing substances in gas and vapour form in a stream of exhaust air (18) with an active material on the surface of a carrier, the exhaust air flows through the substrate arranged in a housing (68) with gas inlet (90) and outlet stubs (78). In the housing (68) there are several axially separated cartridges (12) closed on one side, with an indeformable, perforated inner casing and an outer casing permeable to gases with little resistance as a carrier with the active material for the catalysis, adsorption or transformation of organic dusts and aerosols into gas placed on its surface. The cartridges (12) are assembled into at least one removable insert (70) or removable modules, each with individually releasable cartridges (12). The device makes it possible to purify gaseous and vapour flows of exhaust air at varying and low charges and low temperatures, where the devices may be spatially andlocally separated.

Description

The invention relates to a device for exhaust air purification according to the The preamble of claim 1 features specified.

Such a device is known from WO 93/23657, which has diesel engines used to filter soot particles and especially in gaseous Convert carbon dioxide. This device is used primarily in motor vehicles used and is based on the specified mileage or upon detection an ineffectiveness that arises over time and replaced with a new device. The device contains in a housing a number of axially spaced cartridges with a perforated Inner jacket and a gas-permeable outer jacket with active Material, where a replacement of the active material or an exchange of sub-components the device is not easily possible. The individual cartridges are screwed in the area of the gas outlet side with bolts, but is in the area of Gas inlet side welded a plate to the open ends of the individual pipes. Reprocessing the device or reusing individual Components of the same are not easily possible.

Furthermore, exhaust air purification systems are often used as thermal exhaust air purification units operated at high temperatures depending on the harmful gas in the exhaust air. The harmful gases occur in fluctuating concentrations and often not at temperatures, where they are burned in a flame or using a catalyst can. Therefore, they have to be burned or heated with a lot of fuel, whereby the heat can often not be used or at the time of combustion either not or to a lesser extent. Often they are also expensive Installations for storage or use of heat necessary or even by law required. In addition, the location of the pollution is sometimes far from that Incinerator removed, so long and expensive channels have to be laid.

In view of these circumstances, the inventor has set himself the task of To create device of the type mentioned, which an exhaust air purification and thus enabling pollutant removal at temperatures as low as possible and which allows a simple recycling concept with a durable, robust construction as well as universally usable.

This object is achieved in accordance with that specified in claim 1 Characteristics.

Special and further developing embodiments of the device according to the invention are the subject of dependent claims.

With the device according to the invention there is the advantage of a large, predetermined and defined gas path over the entire inflow range of the Cartridges. In particular, gaseous and vaporous exhaust air streams can fluctuating and weak loads and cleaned at low temperatures are, the devices can be spatially and spatially separated. The Cartridges are for at least one removable insert or removable Modules with individually releasably attached cartridges. Further are in the area of cartridges open cartridge holder sealant for sealing the Cartridge interior with regard to that existing outside the respective cartridge Provided space.

The cartridges with the carriers for catalysis, adsorption and conversion of organic Dusts and aerosols in gas can be separated from each other locally and spatially Housings or units may be arranged, the adsorber unit even can be mobile. The outer jacket can be made of active material or with this be coated.

During the operation of the device according to the invention, subsequently exhaust air purification system called, can affect the active material of the cartridges in a lot Reduce the amount of non-flammable deposits. Also certain substances poison or clog the active material. Are the characteristics of the active Material as a result of this incombustible Deposits or due to poisoning are no longer sufficient, the relevant application or the relevant Module removed, one or more cartridges removed and that active material cleaned or renewed. Even with a renewal of the active material, the inner jacket of cartridges, also called perforated tube, can be used several times. This saves valuable resources and economic efficiency increase.

The cartridges are closed and downstream open upstream. You are on the gas inlet side with an open cartridge holder in the area of the cartridges, on the gas outlet side with one in the area screwed open cartridge holder between the cartridges. Particular attention should be paid to the seal, it may no creeping gas flows past the filter medium, rather, the entire exhaust gas flow must pass through the filter medium be led.

The screw connection of the individual parts creates solid Catalyst inserts or catalyst modules, which are in themselves are stable. The seal can be preferably a multi-part Clamping piece, which is adjacent on the inside of the downstream cartridge holder is arranged and a seal on the rigid inner shell of the cartridges acts.

The holding and supporting parts of the catalyst system are preferred made of a high-alloy steel. This can cause a Scaling of the metal parts largely prevented and a very long lifespan can be achieved. Special attention is the formation of the inner shell of cartridges donated. The porosity is usually determined by training of round and / or elongated holes in a sheet metal jacket. A cylindrical surface with the necessary mechanical strength can also with a wire or Belt grating can be reached.

The rigid inner jacket has the outer jacket of the cartridges supported with the active material. Preferably there is Outer jacket made of a heat-resistant, inorganic fiber material from high temperature filaments or yarns high adsorption capacity, the yarns being known per se Way as multifilament or fiber yarn, twisted or unrotated, can be formed. The summary filaments or yarns referred to as fibers are preferred applied as an at least one-layer structured form. However, the outer jacket can also be used as a single or multi-layer knitted fabric, knitted fabric, fleece, braid or the like be applied.

The high adsorption capacity of the high temperature fibers physically expressed by the high van der Waals forces, is achieved through the formation of a high specific surface guaranteed. The high temperature fibers used are preferably made of glass or ceramic.

For a very good efficiency of the exhaust air cleaning system is also important that there are no leaks between the individual inserts or modules can arise, which is unpurified Creep gas flows would result. In particular modules are preferably with an elastic glass fabric seal sealed against each other.

An exhaust air purification system according to the invention is thanks to interchangeable inserts or modules with individually replaceable Cartridges of a simple basic concept, flexible in use and economical in production and operation. With a Small number of elements can be the most diverse exhaust air purification systems be built. To the inexpensive Large batches come with low inventory, which is economical further improved.

The carried out with the device according to the invention Catalytic afterburning of carbon monoxide and hydrocarbons runs flameless in an exhaust air stream much lower temperatures than for example at thermal afterburning. This becomes essential uses less energy and is also proportionate small size achieved.

Carbon monoxide and hydrocarbons in the exhaust air stream can before or simultaneously with the catalytic afterburning be concentrated by adsorption. For this, the Catalyst system in the exhaust air stream an adsorption storage upstream. This can consist of fibers, in particular of knitted, woven or braided activated carbon fibers, Ceramic or glass exist. Here, the fibers can be coated on the catalytically active material, i.e. the Adsorption storage can also serve as a catalyst.

A one-component coating is preferred as the catalytically active material or a mixture of precious metals or from Precious metal oxides, in particular from platinum, rhodium, palladium, Vanadium, cobalt or their oxides with other metals or their oxides used.

In a preferred embodiment, in particular if the adsorption storage is used simultaneously as a catalyst, the catalyst support consists of fibers, in particular of knitted, woven or braided fibers made of activated carbon, ceramic or glass. The size can be considerably reduced by using a coated adsorption fiber. By using a catalyst carrier made of fibers, space velocities of up to 300,000 h ^{-1 are} permitted, compared to 35,000 h ^-1 for a ceramic honeycomb body.

Organic dusts and aerosols can also be heated Cartridges with active material in a structured form decomposed and brought into the gas phase, what their treatment allowed in the exhaust air purification system.

In the event that the exhaust air flow is one for the catalytic Afterburning is too low, this can be heated before entering the catalyst. A another possibility is seen in the catalyst and / or the cartridges themselves are heated.

The ionization or excitation can also be by electrical Fields or chemical additives such as gases are made. With that falls the need to heat up and the energy required is gone many times less than with thermal heating.

The system according to the invention jumps at very low temperatures in the range between a room temperature of about 15 ° C to 450 ° C and only uses about 20% of the energy that thermal post-combustion is required.

With a relatively high load of an exhaust air flow with carbon monoxide or hydrocarbons led directly over the catalyst units. For compensation An upstream adsorption storage device can be used for loading peaks be provided.

At a low load on the exhaust air flow, the catalyst an adsorber upstream as a storage. This Adsorption storage adsorbs even the smallest pollutant concentrations. Then in a second step desorbed over a much smaller cross section and the desorption stream burned in the catalyst. This The process can be independent of fluctuating concentrations of pollutants and take place at different intervals. The system requires approximately 5% of the energy of a thermal one Afterburning and can be in the immediate vicinity of the harmful gas source be installed, which significantly increases the installation costs diminishes. It is not necessary to use heat. The partial flow catalysis system has the advantage that it even with a low concentration of pollutants in the range of a few ppm to 1000 ppm and more. The pollutants will stored in the adsorption storage and then how converted in full flow catalysis in the catalyst.

The device according to the invention can be used with all hydrocarbons as well as carbon monoxide and optionally others gaseous compounds are used, in particular for flameless solvent combustion, catalytic Residue combustion and odor removal.

The particular advantage of the invention is that System starts at very low temperatures and above all can be built in modules that are spatially separated can. It is even possible that e.g. the adsorption does not in the same gas flow as the cleaning. This allows cheap adsorber modules are manufactured, which at Issuers are installed and at a service point be cleaned.

Areas of application are e.g. Production processes in chemistry, Pharmaceutical and food industry, roasting plants, smokehouse, Paint production and processing, spraying, Paint shops, textile processing and finishing, ceramic production and processing, fuel exhaust air, Wood processing, particle board exhaust, printing industry, Plastics industry etc.

• Fig. 1 eine teilweise aufgeschnittene Seitenansicht eines Katalysatormoduls einer stationären Katalysatoranlage;
• Fig. 2 eine Stirnansicht des Moduls von der Abluftaustrittsseite;
• Fig. 3 eine Stirnansicht des Moduls von der Ablufteintrittsseite;
• Fig. 4 eine teilweise aufgeschnittene Ansicht einer Patrone;
• Fig. 5 eine teilweise detaillierte Ansicht des Innenmantels der Patrone;
• Fig. 6 eine Ansicht eines mehrteiligen Klemmstücks;
• Fig. 7 eine aufgeschnittene Ansicht einer mobilen Katalysatoranlage mit einem Katalysatoreinsatz;
• Fig. 8 einen Radialschnitt bei VIII - VIII in Fig. 7;
• Fig. 9 einen Katalysatoreinsatz für Fig. 7;
• Fig. 10 der stromab liegende Patronenhalter von Fig. 9;
• Fig. 11 der stromauf liegende Patronenhalter von Fig. 9;
• Fig. 12 ein Klemmstück des Katalysatoreinsatzes nach Fig. 9;
• Fig. 13 einen Axialschnitt durch eine Filterpatrone im Bereich der Eintrittsseite;
• Fig. 14 das Prinzip einer Vollstrom-Abluftreinigungsanlage;
• Fig. 15 das Prinzip einer Teilstrom-Abluftreinigungsanlage.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawing; this shows schematically in

• Figure 1 is a partially cutaway side view of a catalyst module of a stationary catalyst system.
• 2 shows an end view of the module from the exhaust air outlet side;
• 3 shows an end view of the module from the exhaust air inlet side;
• Fig. 4 is a partially cutaway view of a cartridge;
• Fig. 5 is a partially detailed view of the inner shell of the cartridge;
• 6 is a view of a multi-part clamping piece;
• 7 shows a cut-away view of a mobile catalytic converter system with a catalytic converter insert;
• 8 shows a radial section at VIII-VIII in FIG. 7;
• FIG. 9 shows a catalyst insert for FIG. 7;
• Fig. 10 shows the downstream cartridge holder of Fig. 9;
• Fig. 11 shows the upstream cartridge holder of Fig. 9;
• FIG. 12 shows a clamping piece of the catalyst insert according to FIG. 9;
• 13 shows an axial section through a filter cartridge in the region of the inlet side;
• 14 shows the principle of a full-flow exhaust air purification system;
• Fig. 15 shows the principle of a partial flow exhaust air cleaning system.

A catalyst module 10 of a stationary catalyst system 1 to 3 is essentially cuboid, it has a cross section of 150 x 150 mm and one Length of 1000 mm. A module comprises nine cartridges 12 with one dimensionally stable inner jacket 14 with a diameter of approximately 34 mm and an outer jacket 16 made of a braided inorganic Fiber material that is stocking-like over the inner jacket 14 is pulled.

The cartridges 12 are downstream with respect to an exhaust air flow 18 provided with a cap 20. The exhaust gas stream 18 enters the interior 28 of the cartridges 12 that are open upstream and passes through the porous inner jacket 14 and the fibrous Outer jacket 16 in the interior 26 between the Cartridges 12. The cleaned exhaust air 18 flows through openings in the cartridge holder 24. At the entrance end of the upstream open cartridges 12 is a coaxial via a clamping bracket 34 Flanged sleeve 30 attached. The sleeve 30 penetrates accordingly dimensioned openings 36 in the upstream filter cartridge holder 38. Cap 20 and flange sleeve 30 are connected to the inner jacket by spot welding, not gastight. The sealing is done by one front clamping bracket 34, which on the outer jacket 16th put on and in the area of the cap 20 and the Flange sleeve 30 are tightened.

On the inside is a multi-part clamping piece 40, 42, which is shown in detail in FIG. 6, with the cartridge holder 38 screwed, the screw connection is designated 56. This Clamp is used to seal the interior on the inlet side 26 around the cartridges 12 and thus the prevention of Leakage currents. The seals are designated 44, 46.

Downstream is the closure cap 20 of the cartridges 12 via a Threaded bolt 48 and a corresponding nut 50 attached to the cartridge holder 24. Finally, the dimensional stability of the catalyst module 10 is further improved, by the cartridge holder 24 having an inwardly folded edge 52, the cartridge holder 38 has a folded edge 54. At the Stacking modules 10 form the folded edges 52, 54 the contact surfaces.

On the outflow side of the catalyst module shown in FIG 10 is the bowl-shaped cartridge holder 24 with in essential square recesses. The above the caps 20 screwed cartridges on the face leave an interior space 26 downstream, which thanks to the openings 22 the cleaned exhaust air flows through without any problems becomes.

3 are located in the upstream cartridge holder 38 in addition to the openings 36 for the inner jacket of the cartridges Screws 56 for the clamping piece 40, 42 visible.

The inner jacket 14 of a cartridge shown shortened in FIG. 4 12 (FIG. 1) comprises the closure cap at the downstream end 20 with a welding stud 48, which as Threaded rod is formed. At the upstream end of the Inner jacket 14 is a flange sleeve 30, also called a collar, mounted and spot welded to the inner jacket.

Fig. 5 shows the spread, also shown shortened Inner jacket 14 according to FIG. 4. The porosity exists in regularly arranged round holes 58, which over the whole inner jacket 14 are distributed. Have the round holes 58 in the present case a diameter of 5 mm and one distance d of 7 mm on all sides. So the hexagonal ensures Punching sufficient mechanical stability to Wear the fibrous outer jacket 16 (Fig.1).

The multi-part clamping piece, of which one end and one middle piece 40, 42 are essentially shown in FIG. 6 semicircular recesses 60, which correspond in total to the number of cartridges to be accommodated. The recesses 60 are approximately 1 mm larger Radius than the flange sleeve 30. Next are screw holes 62 provided which the attachment to the upstream Cartridge holder 38 (Fig. 1.3) serve.

7,8 show a mobile catalytic converter system 66 with an in a removable catalyst insert disposed in a catalyst housing 68 70. The housing is in a surrounding this Insulation layer 76 embedded. A stationary catalytic converter in the sense of Fig. 7,8 can be used instead of a catalyst 70 any number of catalyst modules 1 included.

The exhaust air stream 18 to be cleaned flows over a flanged one Gas supply nozzle 90 into the catalyst housing 68 in the area of the catalyst insert 70, which is shown in FIG. 9 is shown in detail. Downstream is a gas discharge nozzle 78 am Flanged catalytic converter housing 68.

A pipe 92 passes through adjacent to the gas discharge nozzle 78 with cable sheath the insulation layer 76 and the catalyst housing 68. It serves to introduce a measuring probe and is locked when not in use.

FIG. 8 shows a radial section VII-VII according to FIG. 7. The catalyst insert 70 comprises nineteen cartridges 12 with inner jacket 14 and outer jacket 16. The catalyst housing 68 with the insulation layer 76 is from a clamping ring Surround 94, which can be determined with a screw 96 is.

In Fig. 8 is also shown as an example that within of the inner jacket 14 rod-shaped electrode elements for excitation the vapors and gases are arranged by means of electrical fields could be.

The catalyst insert 70 shown in FIG. 9 corresponds essentially a catalyst module 10 according to FIG. 1 hexagonal design of the cartridge holder forming the outer circumference 24, 38 or from their folded edges 52, 54 (FIG. 1), the catalyst insert 70 becomes the catalyst module 10 with nineteen cartridges 12. The foremost cartridge 12 of the middle level is visible in full size, the rest are partially covered.

With a larger exhaust air volume flow, the catalyst can be used 70 by creating more wreaths of cartridges be enlarged. For mechanical and static reasons there must be a limit to the number of catalyst applications be determined by cartridges, the catalyst insert replaced by several catalyst modules.

The cartridge holder 24 according to FIG. 10 on the outlet side corresponds essentially to Fig. 2. Because of the hexagonal The structure of the catalyst insert 70 is the openings 22 however triangular. The nineteen holes 98 are used to hold threaded bolts 48 (FIG. 4) for fastening of the cartridges, not shown. Analogue corresponds the cartridge holder 38 according to FIG. 11 of the previous FIG. 3. The numerous holes 100 are used to attach one multi-part clamping piece.

One assigned to the cartridge holder 38 on the entry side 12 is formed in five parts. The two terminal clamps 40 have on their straight On the long side three essentially semicircular recesses 60, which has a radius about 1 mm larger than that Have flange sleeves 30 (Fig. 4). The four middle clamps 41 have three to five corresponding on their long sides semicircular recesses 60. Between the Clamping pieces 40, 41 are each approximately 1 mm wide slot 104 recessed. The arrangement of the holes 100 for the screw connections 56 (Fig. 1.9) corresponds exactly to that of cartridge holder 38 arranged upstream.

13 shows a variant of the sealing of the interior 26 (Fig. 1,2) outside the cartridges in a catalyst module or catalyst insert. Adjacent to the face the inner jacket 14 is a spot welded flange sleeve 30 on. An abutting face of this flange sleeve Clamp 40, 42 presses when tightening the screws 56 (Fig. 1,9) the flange sleeve 30 against the seal 44 and the cartridge holder 38. The cartridges 12 do not have to be with one Seal held in the cartridge holder 38.

In a full flow exhaust air purification system 110 occurs according to 14 the exhaust air laden with hydrocarbons an exhaust air inlet 112 and a vetilator 114 in a treatment room 116. In this treatment room 116 a catalyst 118 is arranged, which is designed as the device according to the invention. Before entering the Catalyst 118 can take the exhaust air through to the treatment room 16 connected hot air blower 120 preheated become. Leaves after exiting catalyst 118 the cleaned exhaust air the treatment room 116 via a Clean air outlet opening 122.

A partial flow exhaust air purification system shown in FIG. 15 130 has an exhaust air inlet opening 132 and one adjoining fan 134. In a treatment room 136 is arranged a catalyst 138 which is designed as the device according to the invention. To the treatment room 136 is a hot air blower for preheating air 140 upstream of the catalyst 138. The exhaust air flows out here first in an adsorption memory 144, in which Carbon monoxide or hydrocarbons are adsorbed. The exhaust air cleaned in this way leaves the adsorption store 144 via the clean air outlet opening 142. With sufficient The loading of the adsorption storage 144 becomes the hydrocarbons by introducing a desorption gas via a desorption line 146 by means of a compressor 148 desorbed, possibly heated via the hot air blower 140 and then fed to the catalyst 138. After this Passing through the catalyst 138 is the cleaned Exhaust air via a connecting line 150 to the clean air outlet opening 142 out.

The device according to the invention acts selectively particularly well for CO from approximately 150 ° C. and, depending on the temperature range and active material of the cartridges, well for C _m H _n .

Claims (12)

1. A device for exhaust air purification of gaseous and vaporous substances, having a housing (68) through which an exhaust air stream (18) flows, with several cartridges (12) which are closed at one end running axially at a distance and have a dimensionally stable, perforated inner jacket (14) and an outer jacket (16) designed to be gas-permeable with a low resistance as a carrier with an active material for catalysis, adsorption or conversion of pollutants in gas, where the cartridges (12) are connected at the gas inlet side to a first cartridge holder (38) which is open in the area of the cartridges (12), and they are also detachably connected at the gas outlet side to a second cartridge holder (24) which is open in the area between the cartridges (12),
   characterized in that the cartridges (12) are combined into at least one insert (70) or modules (10) that can be removed from the housing (68),

   the cartridges (12) are detachably attached individually in the insert (70) or module (10), and

   sealing means (40, 42, 44) are provided for sealing the interior space (28) of the cartridge in the area of the first cartridge holder (38) with respect to the space (26) outside the respective cartridge (12).
2. A device according to Claim 1, characterized in that the cartridges (12) with the carriers for catalysis, adsorption and conversion of organic dusts and aerosols in the gas are arranged in separate housings (68) or units.
3. A device according to Claim 1 or 2, characterized in that the outer jacket (16) is made of or coated with an active material.
4. A device according to one of Claims 1 through 3, characterized in that the cartridges (12) are encompassed upstream by a preferably multipart clamping piece (40, 42) with a tolerance, said clamping piece acting on a gasket (44) placed between the clamping piece (40, 42) and the cartridge holder (38) and sealing the interior space (26) outside the cartridges (12).
5. A device according to Claim 4, characterized in that the clamping piece (40, 42) is designed essentially in a strip, with essentially semicircular recesses (60) for the cartridges (12).
6. A device according to one of Claims 1 through 5, characterized in that a sealing cap (20) inverted over the inner jacket (14) of the cartridges (12) serves to fasten the cartridges (12) downstream, and upstream a flange sleeve (30) serves to fasten the cartridges, with the sealing cap (20) and the flange sleeve (30) preferably being attached to the inner jacket (14) by spot welding.
7. A device according to Claim 6, characterized in that the outer jacket (16) is attached with an airtight seal to the sealing cap (20) and the flange sleeve (30) with strap clamps (34).
8. A device according to one of Claims 1 through 7, characterized in that the holding and supporting parts, in particular the inner jacket (14) of the cartridges (12) and the cartridge holders (24, 28) are made of a high-alloy steel.
9. A device according to one of Claims 1 through 8, characterized in that the inner jacket (14) of the cartridges (12) has round holes (58) and/or elongated holes or is designed as a wire mesh or a band grid.
10. A device according to one of Claims 1 through 9, characterized in that the active material consists of a single-substance coating or a mixture of noble metals or noble metal oxides, in particular platinum, rhodium, palladium, vanadium, cobalt or the oxides thereof with other metals or the oxides thereof.
11. A device according to one of Claims 1 through 10, characterized in that the carrier or the outer jacket (16) of the cartridges (12) consists of fibers, in particular knit, woven or braided fibers of activated carbon, ceramic or glass.
12. A device according to one of Claims 1 through 11, characterized in that the modules (10) are sealed with respect to one another by an elastic glass cloth seal.

Images