EP0815395B1 - Device for thermal waste gas treatment, in particular oxidizable low-temperature carbonization gases - Google Patents

Abstract

The invention concerns a device for the thermal waste gas treatment, in particular of oxidizable low-temperature carbonization gases, the device comprising a first reactor (4) with a heat-accumulator body (A), a heating zone (6) and a second reactor (5) with a heat accumulator (B). Waste gas is alternately fed to and removed from the reactors arranged in series. The reactors (4, 5) are disposed in an elongate horizontal situation with heating zones arranged therebetween. The ends (11, 12) of the reactors are provided with inlets and outlets (13, 14, 15, 16) with controllable flaps (20, 21, 22, 23) for the waste gas.

Description

The invention relates to a device for thermal exhaust gas treatment, in particular of oxidizable carbonization gases, with the features of the preamble of claim 1.

EP 0 472 605 B1 describes a system and a method for thermal exhaust gas treatment known in which the reactors are arranged as vertical towers. There will be at least used two reactor towers. The entry and exit of the exhaust gases is provided at the bottom of the reactor towers. The top ends the reactor towers are connected via a deflection housing. There there is also a combustion chamber with burners. The reactor towers are filled with ceramic bodies. The one with organic Raw gas loaded with pollutants enters a reactor tower and is when flowing through the hot heat storage body heated up. The raw gas is in the heating chamber a burner, e.g. Natural gas burners, on those for Post-combustion of the organic harmful gases necessary temperature heated up. The heated, cleaned exhaust gas is the second reactor tower slides in and out in the first tower taken from the memory and added in the deflection channel Heat as completely as possible in the second tower to the storage off again. The cooled clean gas, which emerges from the second reactor tower has a slightly higher temperature than the raw gas when entering the first reactor tower then derived over the chimney.

The gas flows are at regular intervals, e.g. from approx. two to three minutes, switched. The second reactor tower now the function of heating the Raw gas, while the storage in the first reactor tower the heat of the hot clean gas.

The construction of reactor towers is for static reasons complex. The introduction of the storage trimmings into the reactor towers is cumbersome. In addition, the guidance of the exhaust gases is like it is also difficult to remove deposits.

From EP 0 365 262 A1 it is also known in such systems that to use a single reactor tower in which the two reactors arranged one behind the other with an intermediate Take up the combustion chamber in an extended position. Also the disadvantage here is that for reasons of statics a complex Construction is required. The individual trimmings are also to intercept the reactors with appropriate support grids, which in turn is expensive for static and thermal reasons must be built.

Finally, DE-OS 2 301 445 describes a method for Detoxification and deodorization of gases and vapors through thermal treatment and a suitable device known, which also has two reactors, which alternately from the outer end of the device cleaning gases are supplied. However, the device is again with reactors arranged one above the other, i.e. vertically standing trained. The reactors each have heat storage Material on in the hot zones, that is, in the areas adjacent to the firing zone, made of ceramic and are made of cast iron in the areas further out can.

The invention has for its object a device to create thermal exhaust gas treatment, which is an easier one Design with simplified statics possible. In addition is intended to insert and remove the memory in the device be relieved. Removing deposits and the guidance of the exhaust gas flows in the device should be improved become.

The invention solves this problem with the features of the claim 1.

By providing metal parts according to the invention in The form of tightly hanging chains is a minor one Installation length of the reactor is achievable because it is much faster Heat transfer is possible.

The tightly hanging chains make it easy Cleaning deposits that are deposited on them to have. By simply shaking the chains, e.g. manually or by an automatic device, the can to the Chain parts accumulating residues, e.g. Dust or Soot to be removed.

The stretched, lying device for thermal exhaust gas treatment with reactors with combustion chamber in between simplifies the statics and thus the construction of the reactors. There is therefore the possibility of using reasonable technical and allow financial outlay also higher storage masses. This can come up as soon as there is a major temperature fluctuation of the exhaust gases to be cleaned or alternating Pollutant concentration must be managed.

As a result, longer switching cycles between gas heating can also occur and cooling can be selected without the afterburning process is adversely affected. This in turn results in lower unpurified gas quantities resulting from the dead space volume result during the switching process. So it will only a small proportion of unpurified exhaust gas is emitted. As a side effect there is less mechanical stress, e.g. B. Wear of the movable parts of the switching flaps on.

The possible higher storage mass also requires a higher one free flow area. This will make a lower one Cross-sectional load of the device reached. Especially with higher dust and soot loading of the exhaust gas to be cleaned the risk of the free cross-sections in the device increasing practically excluded. Associated with this is a lower total pressure loss of the device. this means a lower expenditure of electrical energy for operation of the exhaust fan.

Finally, there is also an extension to be carried out later the device easily possible. For this, the device be built in modular construction. When extending the device one or more modules can then be added.

The stretched, lying arrangement also improves the guidance of the exhaust gas. So is the pressure loss due to the omission of a deflection channel decreased.

According to one embodiment of the invention, the reactors are included Heating chamber designed to rest on the floor.

If there is no space, it is also possible to have one Attach device above other overall system parts.

According to another embodiment of the invention, each heat store made of refractory stones with slits between in Longitudinal successive rows of stones built. Through the setting slots, the mixing of the Exhaust gases. Auxiliary burners and / or circulation fans are in the insertion slots applicable.

Preferably, chamotte multi-hole stones are found for each heat store Use.

According to a further embodiment of the invention, the stones each heat accumulator to its longitudinal direction with the perforated channels arranged obliquely, the oblique channels in the lower half against the channels in the upper half run. As a result, in the subsequent open spaces, e.g. Combustion chamber or hood-like ends, an improved Mixing of the exhaust gases achieved.

According to a further embodiment of the invention, as Stones Solid stones for transverse bands in the heat storage be used.

The stones are preferably arranged as double impacts have successive distances to form the setting slots.

According to a further embodiment of the invention Ceiling and / or the side walls of the heating chamber, Burners arranged offset in height are provided. Hereby the exhaust gases are circulated in the heating chamber.

In order to be able to easily walk through the heating chamber, e.g. Deposits to remove is a side wall of the heating chamber with a Provide door over which a burner is arranged.

According to a further embodiment of the invention, the outer jacket the plant is formed by a housing at each end a collecting hood with connections for incoming and outgoing connections for the exhaust gas and nozzle with control flaps for the alternating lines.

Any collector hood that is tubular with rectangular or round Cross-section is formed, may have a flat end face, which is designed as a lifting gate. You can use this lift gate the storage inventory of each reactor, e.g. B. by a forklift retracted and extended. The memory stocks can in terms of their structure, size and composition to changed conditions, e.g. B. changed exhaust gas values prescribed Limit values and the like can be adapted.

The outer housing is preferably thermally insulated on the inside and / or outside.

In order to also remove deposits from the heat stores led out in the slots in the middle near the bottom, lockable pipe socket available. Make this possible the introduction of a suction hose for vacuuming the Deposits.

To improve the heating of the heat storage can Ends instead of stones tube stack made of good heat-conducting material, e.g. Copper.

The placement slots of the heat accumulators can be pourable material must be filled. This will Heat storage value increased.

Further refinements of the invention result from the other subclaims.

Fig. 1

eine schematische Darstellung der Draufsicht auf die Vorrichtung nach der Erfindung,

Fig. 2

einen Querschnitt nach der Linie II-II in Fig. 1,

Fig. 3

eine Teil-Stirnansicht eines Wärmespeichers,

Fig. 4

eine Teil-Draufsicht des Wärmespeichers, und

Fig. 5 und Fig. 6

Ansichten wie in Fig. 1 und 2 einer geänderten Ausfürungsform

The invention is explained in more detail below with reference to an embodiment shown in the drawing. Show in the drawing

Fig. 1

2 shows a schematic representation of the top view of the device according to the invention,

Fig. 2

2 shows a cross section along the line II-II in FIG. 1,

Fig. 3

a partial front view of a heat accumulator,

Fig. 4

a partial plan view of the heat accumulator, and

5 and 6

Views as in Fig. 1 and 2 of a modified embodiment

The raw gas to be burned is fed through a raw gas line 1 fed to the device for thermal exhaust gas treatment 2. The device 2 has an outer housing 3 made of inside and / or externally insulated metal.

The outer housing 3 can be made of divided modules in the longitudinal direction be composed in a manner not shown.

The outer housing is preferably fireproof for insulation Inner lining, e.g. B. from chamotte, ceramic fibers or similar. The steel outside of the housing can also be insulated in a similar way. It should be noted that the occurring temperature does not fall below the dew point.

In the housing 3 there are reactors 4, 5 in a lying position with an intermediate one Heating chamber 6, preferably arranged, arranged. The device 2 preferably rests on the floor 10. Due to the horizontal arrangement, the statics and construction considerably simplified.

The ends 11, 12 of the outer housing 3 of the device 2 are hood-shaped. They have connecting pieces 13, 14, 15, 16. Controllable flaps 20, 21, 22, 23 are arranged in these.

The opposing nozzle 14, 16 are over a external pipe 25 connected. They are the same Connection piece 13 and 15 via an external pipe 26 connected to each other.

The pipes 25, 26 are depending on the position of the flaps 20-23 flowed through in one or another sense of the exhaust gas.

The hoods 27, 28 at the ends 11, 12 have drivable doors 30, 31. Above them can be limited by the hoods 27, 28 Spaces of the ends 11, 12 are cleaned of exhaust gas residues. In addition, the components of the heat storage 35 in the Outer housing 3 are introduced.

The heat accumulator 35 is divided into two groups A, B. Each of the Groups A, B are formed by a trimming body 38. This consists preferably of chamotte multi-hole stones 39.

The trim body 38 is preferably of mutually inclined Stone rows 45 formed. The one in the top half arranged chamotte multi-hole stones 39 are among those in the lower half arranged stones 39 running in opposite directions appropriate. This creates a better swirl effect (Mixing) reached.

A band 47 made of chamotte multi-hole bricks is preferably in the middle in terms of height intended. The more precise stocking with the Chamotte multi-hole bricks 39 can be seen from FIGS. 3 and 4. All stones 39 are of the same design. You own across a plurality of perforations 48 along its longitudinal direction.

The upper layer 49 and the lower layer 50 are made of stones 39 formed, the side and without a large distance from each other connect to each other at the front. The longitudinal axes of the stone rows are opposite to each other and at an angle to the direction of flow 55.

The stones 39 of the middle layer 56 are perpendicular to the direction of flow 55 of the exhaust gas arranged. They are on the front Stones 39 arranged abutting. In the direction of flow 55 of the exhaust gas they are spaced apart.

The facing body 38, which through the chamotte multi-hole stones 39 is formed, has transverse to the flow direction 55 Set slots 36. This creates transverse Trim body discs 37. These are preferably made of chamotte multi-hole stones 37 assembled. There can also be a number of solid stones housed in these trimmings 37 be. This creates an additional redirection and thereby better mixing of the exhaust gas.

The trim body disks 37 are generally as double joints erected that are at a distance from each other Forming slots 36 to form. Reached through the setting slots 36 a certain calming of the exhaust gas flow and a Temperature equalization.

In the setting slots 36 additional auxiliary burners can be used Ceiling and / or side burners can be arranged. This will the circulation of the exhaust gases in the setting slots 36 is improved. In addition, a temperature equalization in the reactor 4 or 5 reached. Temperature fluctuations are also smoothed out.

Between the two heat storage groups A, B is in series and the heating chamber 6 is arranged in the extended position. As from Fig. 2 can be seen, the outer housing 3 preferably has an im essentially rectangular cross-section, preferably square Cross-section. In this heating chamber 6 are preferred two burners 40, 41 arranged as the main burner. It can too Side burners are used. These are for the revolution of the Exhaust gases in the heating chamber 6 are offset in height. So is e.g. burner 40 is located near the top of chamber 6, while the burner 41 on the opposite side wall of the outer housing 3 is arranged near the bottom 10.

This also facilitates the attachment of a door 42. Above this is a clearing of any deposits in the Heating chamber 6 possible. In addition, the introduction of the Trimming for the heat storage groups A, B are made possible.

The combustion chamber 6 as well as the setting slots 36 can briefly the bottom 10 with outwardly leading, closable pipe sockets be provided, which is also the introduction during operation a suction hose and the removal of any Allow deposits.

It can cope with extreme requirements, such as large fluctuations of raw gas quantities and pollutant concentrations, circulation fans be used both in one and in several Set slots 36 are arranged and circulate in one direction or can be switched in the opposite direction.

On the two ends 11, 12 under the hoods 27, 28 hanging metal chains are arranged, which results in a faster heat transfer achievable and the dimensions of the two heat storage groups A and B can be shortened. The close together hanging chains allow easy cleaning of deposits, who have put down on them. By simple Shaking the chains, e.g. manually or by an automatic Device that can accumulate on the chain parts Residues, e.g. Dust or soot. Preferably these chains are located in the area of the ends 11, 12 the hoods 27, 28 arranged.

The operation of the device 2 is shown in connection with FIG. 2 explained. The controllable flaps 20, 21, 22 and 23 are located themselves in the drawn positions. Then the afterburning flows cool raw gas via lines 1 and 26 to the connecting piece to, is fed to the reactor 5 and takes heat from the trimming body 38. The exhaust gas is then in the Heating chamber 6 further heated. The exhaust gas continues to heat then the one previously cooled in the previous operating phase Trimming body 38 of the regenerator 4 back to the optimal temperature (e.g. 800 ° - 900 ° C). The exhaust gas then flows over the free connection piece, the pipeline 25, the pipeline 60, the fan 61, from the chimney 62 to the outside.

When after a while - e.g. B. several minutes - subsequent operating phase, the exhaust gas via line 1 fed to the reactor 4 when the flap 20 is reversed. Since the further flaps 21, 22 and 23 in their reverse flap position are located, the exhaust gas flows through the heating chamber 6 to the reactor 5 and on over the connecting piece 16 to the fan 61, and Chimney 62. The operating phases then repeat themselves.

Due to the chosen structure and arrangement of the memory the device 2 also optimal mixing and reaction zones. The Exhaust gas to be cleaned is always mixed again before it enters the next stocking occurs.

Depending on the type and concentration of pollutants, it begins in partial oxidation in the middle part of one reactor the hot contact surfaces flowing around. These reactions plant within steadily increasing oxidation rates within of the storage population.

At the end of each reactor is then the required Combustion temperatures around 800 ° C the pollutant combustion already completed. The cleaned exhaust gas, which is a big one Contact area had to flow through, is then in the respective following zone for the purpose of delivering energy to the trim elements cleverly.

The temperature resistance of the thermal reactor at which there are no metallic materials in the high temperature range, The standard version is approx. 900 ° C and can be used for Special cases can still be increased. A special The advantage of the device lies in its ability to handle the primary thermal efficiency by varying the stock storage too change.

Due to the modular design, it is possible to change production conditions, e.g. B. reducing or increasing pollutants, adjust the necessary primary energy requirements immediately.

The device can also be operated on a catalytic basis become.

5 and 6, it is also possible to the heating chamber 6 by one or more trimming bodies 38 to replace with slits 36. In this case, the entire Arrangement consisting of a single reactor body be understood, which preferably has set slots 36. In the setting slots 36 are preferably of a heating zone a plurality of trimming bodies 38, burners, preferably one or more to provide tubular high-speed burners 70. The burners could also be operated only partially, if there are flammable components in the exhaust gas. The desired Combustion temperature is switched on and off or control of the burner output regulated. If the pollutant content in the raw gas that is required for autothermal operation Quantity exceeds, a partial volume flow of hot exhaust gas is directly coupled out of the heating chamber or heating zone.

The result is a device 2 with a continuous, preferably same trimmings 38. The length of the heating zone can changed accordingly by switching burner 70 on or off become. There is also the advantage of faster heating the heating zone. The entire trim body can be uniform be formed. The high-speed burners used 70 are cheaper and more effective.

Finally, each end 11, 12 instead of hoods too with a tubular longitudinal part and a flat end part be trained. The tubular end part then has the connecting piece. The flat end part can then be designed as a lifting gate be. The renewable heat accumulation, e.g. B. extended or retracted by a forklift become. The memory stock to be retracted can be outside the device 2 prepared, in terms of its length, its Cross-section and its composition adapted to itself changing conditions, e.g. Exhaust gas composition, limit values etc. to be prepared.

With heavier trimmings with greater heat storage capacity the switching periods are extended.

Claims (21)

1. A apparatus for the thermal treatment of waste gas, particularly of oxidisable carbonisation gases,

   a) having a first reactor (4) comprising a heat storage body A, a heating zone (6), and a second reactor (5) comprising a heat store B,

   b) wherein waste gas is alternately fed to and discharged from the series arrangement of the reactors,

   c) wherein the reactors (4, 5) are disposed in a length-wise position with a heating zone (6) interposed therebetween, and

   d) wherein parts made of material with a good thermal conductivity are provided at the ends (11, 12) of the reactors (4, 5),

   characterised in that

   e) the reactors (4, 5), with the heating zone (6) situated therebetween, are disposed in a horizontal position, and

   f) that the parts made of material with a good thermal conductivity are constructed as closely situated suspended chains.
2. An apparatus according to claim 1, characterised in that the reactors (4, 5) are constructed with the heating zone (6) resting on the ground (10).
3. An apparatus according to claim 1, characterised in that each reactor (4, 5) is constructed with a heat store (A, B) of refractory bricks (39) and fixed slots (36) between the bricks (39) form successive heat storage segments (37) in the longitudinal direction.
4. An apparatus according to claim 3, characterised in that auxiliary burners can be inserted in the fixed slots (36).
5. An apparatus according to claim 3, characterised in that fireclay multihole bricks (39) are used for each heat storage group (A, B).
6. An apparatus according to claims 3, 4 or 5, characterised in that the bricks (39) of each heat storage group (A, B) form channels (48) which extend at a slant in relation to the longitudinal direction thereof, wherein the slanting channels in the lower half (50) run oppositely to the channels in the upper half (49) and that a central course of bricks (50) is present, the channels (48) of which run transversely to the direction of flow (55) of the waste gas.
7. An apparatus according to claims 3 to 6, characterised in that solid bricks are embedded in the transversely extending heat storage segments (37).
8. An apparatus according to claims 3 to 7, characterised in that the bricks (39) are disposed as double baffles and fixed slots (36) are present between the double baffles.
9. An apparatus according to claim 1, characterised in that the heating zone is a heating chamber (6) and the sidewalls of the heating chamber (6) comprise opposed burners (40, 41) disposed offset in height.
10. An apparatus according to claim 9, characterised in that one sidewall of the heating chamber (6) has a door (42).
11. An apparatus according to claim 1, characterised in that each end (11, 12) of the external housing (3) is surrounded by a hood (27, 28) which comprises doors (30, 31) and connections (13, 14, 15 and 16) for the waste gas, and that connection pieces are provided which have controllable butterfly valves (20, 21, 22, 23) for the alternating lines (25, 26).
12. An apparatus according to claim 1, characterised in that closable pipe sockets, which are led outwards in the middle near the ground and into which a suction device can be introduced, terminate in the fixed slots (36).
13. An apparatus according to claim 1, characterised in that recirculating blowers can be inserted in the fixed slots (36).
14. An apparatus according to any one of the preceding claims, characterised in that the chains which are suspended close together are attached to a vibrating device.
15. An apparatus according to any one of preceding claims 3 to 14, characterised in that the fixed slots (36) are filled with heat-storing, pourable material.
16. An apparatus according to any one of the preceding claims, characterised in that an external housing (3) is present which is insulated internally and/or externally.
17. An apparatus according to any one of the preceding claims, characterised in that the heating zone (6) is formed by one or more checkerwork body segments (37) with fixed slots (36) and one or more tubular high-speed burners is/are preferably disposed in each fixed slot.
18. An apparatus according to any one of the preceding claims, characterised in that each end (11, 12) of the external housing (3) is formed by a hood comprising a longitudinal tube part and a flat face part, wherein the face part is constructed as a vertical lift door.
19. An apparatus according to any one of the preceding claims, characterised in that the external housing (3) is built up in the longitudinal direction from module parts.
20. An apparatus according to claim 19, characterised in each housing module part is prepared comprising part of a heat storage body (A, B).
21. An apparatus according to any one of the preceding claims, characterised in that gas is disconnected from the heating zone (6) when a predetermined temperature is exceeded.

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