REGENERATIVE POST-COMBUSTION DEVICE, COATING INSTALLATION, AND METHOD FOR COATING OBJECTS

Abstract

A regenerative post-combustion device which has, along a longitudinal axis, a combustion chamber, a heat exchanger space, which is divided into at least two heat exchanger segments each filled with heat exchanger material, a distribution space which, corresponding to the heat exchanger space, having at least two distribution segments which each communicate with a heat exchanger segment, and a distribution device having at least one exhaust gas passage opening and at least one clean gas passage opening, wherein the exhaust gas passage opening is arranged angularly offset to the clean gas passage opening such that the exhaust gas passage opening communicates with a first distribution segment and the clean gas passage opening communicates with a second distribution segment different from the first distribution segment, and the exhaust gas passage opening and the clean gas passage opening are located at different radial distances from the vertical axis of the post-combustion device. The distribution space has a shut-off device and a bypass line for at least one distribution space segment, the shut-off device being configured such that a partial volume flow can be diverted from the associated heat exchanger segment via the bypass line instead of through the exhaust gas passage opening or/and the clean gas passage opening.

Claims

1. A regenerative post-combustion device comprising along a longitudinal axis: a) a combustion chamber; b) a heat exchanger space, which is divided into at least two heat exchanger segments each filled with heat exchanger material; c) a distribution space which, corresponding to the heat exchanger space, has at least two distribution segments which each communicate with a heat exchanger segment from the at least two heat exchanger segments; d) a distribution device having at least one exhaust gas passage opening and at least one clean gas passage opening, wherein the at least one exhaust gas passage opening is arranged angularly offset to the at least one clean gas passage opening such that the at least one exhaust gas passage opening communicates with a first distribution segment from the at least two distribution segments and the at least one clean gas passage opening communicates with a second distribution segment from the at least two distribution segments, the second distribution segment being different from the first distribution segment, and the at least one exhaust gas passage opening and the at least one clean gas passage opening are located at different radial distances from the longitudinal axis of the post-combustion device; e) the distribution space has a shut-off device and a bypass line for at least one of the at least two distribution space segments, wherein the shut-off device is configured such that a partial volume flow can be diverted via the bypass line from the heat exchanger segment in communication with the at least one of the at least two distribution space segments instead of through the at least one exhaust gas passage opening and/or the at least one clean gas passage opening.

2. The post-combustion device according to claim 1, wherein the shut-off device includes a bypass valve, wherein the bypass valve is configured such that, in a first state of the bypass valve, a throughflow is impeded or prevented and, in a second state of the bypass valve, a substantially free throughflow is possible.

3. The post-combustion device according to claim 2, wherein the bypass line connects the bypass valve of the at least one of the at least two distribution space segments to the combustion chamber.

4. The post-combustion device according to claim 1 further comprising a bypass ring line connected to a plurality of bypass lines.

5. The post-combustion device according to claim 1, further comprising a blower device or/and a heat generating device, wherein the bypass line is connected to the blower device or/and the heat generating device.

6. The post-combustion device according to claim 1, wherein the shut-off device comprises a motorized drive.

7. The post-combustion device according to claim 6, wherein the drive drives a plurality of shut-off devices.

8. The post-combustion device according to claim 1, wherein the distribution device is configured as a rotary distributor.

9. The post-combustion device according to claim 1, wherein the shut-off device -comprises a flap.

10. A coating installation including a regenerative post-combustion device according to claim 1.

11. A method for coating objects such as vehicle bodies with a coating installation according to claim 10.

12. The post-combustion device according to claim 1, wherein the shut-off device is manually operable.

13. The post-combustion device according to claim 1, wherein the shut-off device comprises a flat slide valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In the following, embodiments of the invention are explained in more detail with reference to the drawings.

[0033] FIG. 1 shows a longitudinal sectional view of an embodiment of a post-combustion device with a shut-off device in a first state,;

[0034] FIG. 2 shows a view of the embodiment of FIG. 1 with the shut-off device in a second state;

[0035] FIG. 3 shows a longitudinal sectional view of an alternative embodiment of a post-combustion device with the shut-off device being accentuated;

[0036] FIG. 4 shows a cross-sectional view along plane IV-IV of FIG. 3;

[0037] FIG. 5 shows a cross-sectional view along plane V-V of FIG. 3;

[0038] FIGS. 6-8 show the views of FIGS. 3-5 with the shut-off device in the second state.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0039] FIGS. 1 and 2 show cross-sectional views of a regenerative post-combustion device 1. The basic construction as well as the basic mode of operation are—unless otherwise stated below—described in EP 0 548 630 1 or EP 0 719 984, to which reference is explicitly made. The basic construction and the basic mode of operation of a rotary distributor, as will be described below as a component of the combustion device, are—unless otherwise stated below—described in DE 199 50 891, to which reference is explicitly made.

[0040] The regenerative post-combustion device 1 of FIG. 1 is basically rotationally symmetrical about a longitudinal axis A. The longitudinal axis A usually extends vertically, so that the post-combustion device 1 has the following from top to bottom: a combustion chamber 10, a heat exchanger space 12, a distribution space 14 and a distribution device 16.

[0041] In the embodiment shown in FIG. 1, the aforementioned components are received in a common housing 18. Of course, the housing 18 may also be composed of several parts.

[0042] The combustion chamber 10 has a dome-like basic structure and a burner 20 which can heat the gas volume located in the combustion chamber 10. Depending on the embodiment, temperatures between 750° C. and 800° C. or higher may be achieved, for example.

[0043] In the present case, the heat exchanger space 12 is divided into eight heat exchanger segments 22, two of which are visible in the longitudinal sectional view of FIG. 1. The heat exchanger segments 22 are filled with a heat exchanger material through which exhaust gas or clean gas can flow.

[0044] The distribution space 14 arranged below the heat exchanger space 12 is also provided with the same division into individual distribution segments 24, of which two distribution segments 24.6, 24.2 are shown in FIG. 2. FIGS. 4 and 7 show the arrangement of the distribution segments 24.1-28.8 in sectional views perpendicular to the longitudinal axis 4 of another embodiment. The distribution segments 24 thus correspond in number and fluidic configuration to the heat exchanger segments 22 of the heat exchanger space 12.

[0045] In the embodiment shown in FIG. 1, the distribution device 16 below the distribution space 14 is configured as a rotary distributor 17, as explained in detail, for example, in the aforementioned and referenced DE 199 50 891. The distributor device 16 thus has an exhaust gas passage opening 26 for an exhaust gas supply line 30 and a clean gas passage opening 28 for a clean gas discharge line 32. In the illustration shown in FIG. 1, the openings 26, 28 are only schematically indicated. In a specific embodiment, the passage openings 26, 28 may, for example, be arranged at different radial distances from the vertical axis A. In this way, a connection to the exhaust gas supply line 30 or the clean gas discharge line 32 may be implemented for each heat exchanger segment 22 or distribution segment 24 via corresponding annularly arranged flow spaces within the distribution device. An opening or closing of the passage openings 26, 28, which are arranged angularly offset relative to one another such that the exhaust gas passage opening 26 communicates with a first distribution segment 24 and the clean gas passage opening 28 communicates with a second distribution segment 44 different from the first distribution segment 24, opens up, starting from the exhaust gas supply line 30, different flow paths through one or more distribution segments 24 or heat exchanger segments 22 into the combustion chamber 10 and vice versa from the combustion chamber 10 to the clean gas discharge line 32.

[0046] In the embodiment shown in FIG. 1, the distribution space 14 is provided with several shut-off devices 100 in its lower region, i.e., facing away from the combustion chamber 10. The shut-off devices 100 each comprise a shut-off flap 102 and a bypass line 104, two of which are shown in each of FIGS. 1 and 2. FIGS. 4 and 7 of the alternative embodiment show the arrangement of the shut-off devices 100.1-100.8 and the shut-off flaps 102.1-102.8 and the bypass lines 104.1-104.8, respectively, in a cross-sectional view.

[0047] The shut-off flaps 102 are arranged in the distribution space 14 such that, in a closed position of a shut-off flap 102, an overflow from the respective distribution segment 24 into the distribution device 16 and thus, in particular, into the clean gas discharge line or, conversely, from the exhaust gas supply line via the distribution device 16 into the distribution space 14 or the heat exchanger space 12 is prevented. In contrast, in an open position of a shut-off flap 102, overflow from the exhaust gas supply line 30 into the heat exchanger 12 or from the heat exchanger 12 into the clean gas discharge line 32 is possible. In general, the shut-off flaps 102 may be configured to be movable only to an open position or a closed position. Alternatively, it is also possible to configure the shut-off flaps 102 such that intermediate positions may also be adopted. This enables control of a partial volume flow that can be directed via the bypass line 104.

[0048] The individual bypass lines 104 are provided at each of the distribution segments 24 and are interconnected by a common ring line 112. Furthermore, the ring line 112 is connected to the combustion chamber 10 by a line 114, a blower 116 and a line 115. In the ring line 112 or in individual bypass lines 104, a pressure gradient can be generated, for example, by the blower 116 in the direction of the combustion chamber 10.

[0049] In the embodiment shown in FIG. 1, the two shut-off flaps 102 shown are each in an open position.

[0050] In the embodiment shown in FIG. 1, the bypass lines 104 are each provided with a bypass valve 106. The bypass valve 106 allows the bypass line 104 to be blocked when the shut-off flaps 102 are in an open position, and releases the respective bypass line 104 if the shut-off flap 102 is fully or partially closed and flow into the clean gas discharge line 32 or inflow via the exhaust gas supply line 30 is prevented.

[0051] In addition to the shut-off device 100, the distribution space 14 has collecting plates 108 and dripping plates 110. The aforementioned structures 108, 110 prevent fouling of the shut-off device 100 by condensing or dripping material from the heat exchanger space 12. At the same time, the material collected in the collecting plates can be converted into less problematic substances under certain operating conditions, which will be explained in more detail later. In one embodiment, the collection plates may also be configured to be heatable.

[0052] Temperature sensors may be provided at the lower end of the heat exchanger segment 22 as well as, for example, in the bypass line 104, which may be used for process control, for example, opening and/or closing the shut-off flaps 102 or/and the bypass valves 106.

[0053] FIG. 2 shows the same embodiment of a post-combustion device 1 as in FIG. 1, in which one of the two shut-off flaps 102 (102.2) shown is in a closed position.

[0054] The operation of the post-combustion device 1 is as follows: Exhaust gas loaded with hydrocarbon compounds, for example, from a coating plant (not shown) is fed in via the exhaust gas supply line 30. Depending on the position of the exhaust gas passage openings 26, this exhaust gas is introduced into certain distribution segments 24 of the distribution space 12 and passes from there into the associated heat exchanger segments 22. The exhaust gas thereby absorbs the thermal energy stored in the heat exchanger segments 22 in order to subsequently, after flowing into the combustion chamber 10, be increased there even further to the required temperature level by means of the burner 20. Depending on the position of the distribution device 16, i.e. the rotary distributor 17 in the embodiment shown in FIG. 1, the clean gas thus purified flows in turn via other heat exchanger segments 22 and associated distribution segments 24 via the clean gas passage opening 28 into the clean gas outlet 32. The clean gas thereby gives off some of its thermal energy to the material in the heat exchanger segments 22. Thus, a temperature gradient is formed within a heat exchanger segment 22 from top to bottom, i.e., from the combustion chamber 10, to the distribution space 14. This temperature gradient can range, for example, from 800° C. in the combustion chamber to 200° C. in the distribution space 14. Any liquid condensate or other liquid or solid components that occur accumulate/deposit in the heat exchanger segments 22 and can be partially collected via the drip plates 110 in the collection plates 108.

[0055] By changing the position of the rotary distributor 17, the flow direction of certain heat exchanger segments 22 changes cyclically after certain periods of time—for example 10 s—via a “moving on” of the passage openings 26, 28.

[0056] As soon as the solid or liquid condensate occurring, for example tar or ammonium compounds, exceeds a certain quantity or a certain operating time is reached, the shut-off device 100.2 can be actuated, as shown in FIG. 2, and the shut-off valve 102.2 can be closed and the bypass line 104.2 released via the bypass valve 106.2. At the same time, the blower 116 can generate the required pressure drop.

[0057] In this way, circulation of the gas located in the corresponding heat exchanger segment 22 occurs. As a result of the continuous circulation over the combustion chamber 10, the temperature level in the corresponding heat exchanger segment 22 is gradually raised, for example to 500° C. on the outlet side (distribution space side), and chemical or physical processes can be initiated or can occur in a desired manner within the concerned heat exchanger segment 22, which lead to a reduction or complete degradation of the deposits within the heat exchanger segment 22, in the distribution segment 22 located therebelow, and/or in the collection plates 108 or the drip plates 110. In this regard, it is preferred that only one or a few heat exchanger segments 22 be removed from normal operation and cleaned.

[0058] FIGS. 3 and 6 illustrate in a longitudinal sectional view a post-combustion device 1′ in a slightly modified embodiment compared to the embodiment in FIG. 1. Identical or comparable features are designated by the same reference sign and are not explained again separately.

[0059] In contrast to the embodiment of FIGS. 1 and 2, in the embodiment of FIGS. 3 and 6 the ring line 112 is connected via a line 118 to a temperature control device 120, which in turn is connected via a line 122 to the combustion chamber 10. The temperature control device 120 can cause a temperature reduction of the gas present in the heat exchanger segment 22 as well as the distribution segment 24 independently of the combustion chamber 10, for example to reduce the heat load for a subsequent blower. If necessary, the temperature control device 120 may also alternatively provide an additional heat input.

[0060] When the shut-off valve 103 is closed and the bypass valve 106 is opened, the gas located in the heat exchanger segment 22 can flow via the bypass line 104 to the temperature control device 120 via the line 118, be tempered there and in turn be supplied to the upper side of the heat exchanger segment 22 via the line 122. In this way, overheating of the heat exchanger material located in the heat exchanger segment 22, of the inner wall of the distribution segment 24 and, if applicable, of the drip plates 110 and collection plates 108 can be achieved, for example, while at the same time protecting a fan by lowering the temperature.

[0061] As can be seen from FIGS. 3 and 4, in the embodiment shown in these figures, the ring line 112 is provided with a branch 124. The branch 124 can serve, for example, to feed the waste gases produced during such a pyrolysis, as well as any solid/liquid reaction materials therein that may not be able to be discharged as clean gas via the line 32, to a controlled disposal. This can occur, for example, at certain operating conditions/temperature levels.

[0062] To further illustrate the invention, FIGS. 4 and 7 each show sectional views along a plane IV-IV (marked in FIGS. 3 and 6, respectively) that runs perpendicular to longitudinal axis A through bypass lines 104.1-104.8. In FIGS. 5 and 8, sectional views are shown along a plane V-V, which is also perpendicular to the longitudinal axis A through the shut-off flaps 100.1-100.8.

[0063] FIGS. 4 and 7 show sectional views of the ring line 112 and associated bypass lines 104.1-104.8 and bypass valves 106.1-106.8. The arrangement and shaping of the ring line 112 as well as the bypass lines 104 is only schematic. In reality, the ring line 112 may be integrated into a housing wall of the housing 18, for example.

[0064] As can be seen from FIGS. 3-8, in the embodiment shown, it is intended to close the exhaust gas passage opening 26 or the clean gas passage opening 28 by means of the associated shut-off flaps 102.1-102.8.

[0065] FIGS. 5 and 8 illustrate the arrangement of the shut-off flaps 102.1-102.8. While in FIG. 5 all shut-off flaps 102.1-102.8 are open, in FIG. 8 a position is shown in which shut-off flap 102.2 is closed but the other shut-off flaps 102.1, 102.3-102.8 are open. This can also be seen accordingly in FIGS. 4 and 7.

[0066] With the shut-off flaps 102.1-102.8 in the position shown in FIG. 4, flow is possible through each heat exchanger segment 22 via the distribution segments 24.1-24.8. The passage openings 26, 28 determine the direction of flow through each heat exchanger segment 22. For example, the heat exchanger segments 22 which are supplied by the distribution segments 24.1-24.4 can be connected to the exhaust gas supply line 30 at their underside with the exhaust gas passage opening 26. At the same time, the heat exchanger segments 22, which are supplied by the distribution segments 24.5-24.8, can be connected at their underside with the clean gas passage opening 28 to the clean gas discharge line 32. Accordingly, for the distribution segments 24.1-24.4 and the associated heat exchanger segments 22, there is a flow from bottom to top from the distribution space 14 in the direction of the combustion chamber 10, and for the distribution segments 24.5-24.8, there is a flow from top to bottom from the combustion chamber 10 in the direction of the distribution space 14.

[0067] When the distribution device 16 is switched further, the flow direction of some heat exchanger segments 22 changes accordingly. If one of the heat exchanger segments 22 is connected to the bypass line 104.2 via a shut-off valve, in FIGS. 6-8 the shut-off valve 102.2 and thus the distribution segment 24.2, the gas flow circulates in this heat exchanger segment 22.

[0068] This remains the case even if the valve device 16 is switched further, so that significantly higher temperatures (for example 450° C.-500° C.) can form in otherwise cooler areas of a heat exchanger segment 22 over several switching cycles and the desired chemical/or physical processes can occur.