DE2124197A1 - Combustion device for smoke - Google Patents

Description

Dipi.-ing. Hans Albrecht -ι Berlin ze cFrohnaio that ■) 3. HAI 1971

Patent attorney CWeet-BerllrV)

Edelhofdamm 26

Postal check account: Berlin Weat 830 26 2124197 Telephone: ζΟ3 \ λ ^ AO 95 68

Bank account: Berliner Bank AQ, Depka 43 <4 01 2S 68 >

1 Berlin 28, account no. 9Ο3Ο

File no. 3835 Your Zelohen: ■ Your Naohrloht from:

CARRIER ENGINEERING COMPANY LIMITED Carrier House, Warwick Row, London S.W. 1, England

Combustion device for smoke

The invention relates to a combustion device used for burning smoke and odorous substances which are entrained in the exhaust gases from industrial ovens, hot air canisters and the like, including the exhaust gases, which are used in systems for the dressing of metal and the like, e.g. treatment with paints or corrosion preventive treatment.

It is known that the gases escaping from hot air ovens, such as baking ovens, in metal painting systems are collected in the oven exhaust gas and released to the outside air through a chimney. In many known methods of this type, the resulting air pollution is insufficient or objectionable to justify the cost of equipment to prevent or reduce such air pollution. Recently, however, this method of removing the exhaust gases has not proven to be satisfactory, and in order to overcome this problem it has been proposed to pass the exhaust gases over burners with an open gas flame, thereby removing the harmful and unburned or partially burned components of the Exhaust gases are burned, thus reducing air pollution to an acceptable level. However, it was found that such burners can be operated uneconomical since the combustion temperature must be higher in the order of 68O ⁰ C or even, and a considerable amount of heat is consumed with the discharged through the chimney to the outside air the exhaust gas.

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It is also known that the use of certain catalysts reduces the combustion temperature considerably However, such catalysts can tend to be "poisoned" or "ineffective" by the constituents of the exhaust gas to be made.

The main problem underlying the invention is to provide an improved combustion device for smoke or To create exhaust gas, in which the specified disadvantages are delayed or eliminated.

The device according to the invention for the combustion of the exhaust gases originating from an industrial process has a Combustion chamber, an inlet duct in the combustion chamber for the exhaust gas, a direct ignition device in the combustion chamber, through which the exhaust gas is allowed to flow and an exhaust pipe in the combustion chamber for the removal of the burnt Exhaust gas and is characterized in that the device has a heat exchanger through which the burned Exhaust gas and a process fluid in a heat exchange relationship for heating the process fluid.

According to a preferred embodiment, the device is the apparatus characterized in that the exhaust gas is passed through the combustion chamber by means of a fan including a Blower wheel is guided in the inlet line.

The direct igniter preferably has a gas burner in the combustion chamber, and any suitable gas burner can be used such as a burner known under the trademark COMBUSTIFUME, and furthermore it can be the gas is the usual industrial gas or natural gas or butane, propane or the like. Act. Any other known Ignition device, such as a light fuel, such as Gasoline or heavy fuel such as diesel oil may be used. After another optional

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In the embodiment, the ignition device is a high-temperature electric furnace with elements which are so heated that the temperature of the smoke or the exhaust gas approximates the combustion temperature is increased, which can amount to 650 to 815 ° C.

The combustion chamber can be a catalyst for the reduction the required temperature at which the exhaust gas burns will.

Advantageously, there is an arrangement for preventing flow of the unburned exhaust gas to the combustion chamber and the supply of fresh air to the same so as to purify the combustion chamber of the exhaust gas and the exhaust duct may have a gas sampling device so as to continuously determine the composition of the combusted exhaust gas monitor.

In a preferred embodiment, the process fluid is the gaseous exhaust gas supplied to the inlet pipe of the combustion chamber, and in this way it becomes exiting burned exhaust gas is used to heat the exhaust gas supplied to the combustion chamber in order to make a more efficient one Combustion process. In this case a second heat exchanger can be provided, downstream of the first Heat exchanger is arranged through which the burned exhaust gas flows and fresh air or other gaseous medium from a suitable source, such as outside air, can be heated into the second heat exchanger and the heated air is then for curing purposes in a paint hot-air chamber or similar system applied.

Optionally, the air can be at an elevated temperature before it enters the second heat exchanger and the air can be forced through the second heat exchanger by means of a fan with an impeller located in the gas line of the second heat exchanger.

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According to a suitable design, the smoke or exhaust gas from the paint hot air chamber or other system at a Temperature of about 175 ° C out and in the incinerator burned at a temperature of 650 to 815 ° C, so that the same through the preheater heat exchanger for the Smoke or the exhaust gases pass through at a temperature of about 650 ° C and the same at a temperature of about 415 ° C leave so that the smoke or exhaust gas is preheated to about 415 ° C before they enter the combustion chamber. There where a second heat exchanger for preheating the Air or other gaseous medium supplied to the chamber is provided, the exhaust gas from the chamber can be at a Temperature of 415 ° C and enters into an indirect heat exchange ratio with air or other gaseous medium at 21 ° C and can then be used for hot air chambers or other systems at a temperature of e.g. about 175 ° C. Optional the exhaust gas can be returned to the hot air chamber or other system for further use of the heat present therein will.

According to a further embodiment of the invention, the Process fluids represent fresh air, which are industrial Process is supplied and the heat exchanger can be an indirect or a direct heat exchanger in which the burned exhaust gas is mixed with the fresh air.

In these embodiments, the burned exhaust gas is not used for heating the incoming exhaust gas, but rather is used the same applied to the heating of a process fluid for use in the industrial process.

The process fluid heated by the burned exhaust gas can be passed through terminal reheaters before using it in the industrial process and it For example, an arrangement for mixing the fresh air with the process fluid can be employed after the process fluid has passed through the heat exchanger. According to a further embodiment, the

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heated process fluids through heat transfer tubes and applied for heating a liquid, optionally the process fluid can also be used for heating of air can be applied and an additional fresh air heating arrangement can be used to supplement the heated process fluid are provided.

An embodiment of the invention is shown in the accompanying drawings and is described in more detail below. Show it:

Figure 1 is a diagrammatic representation of a combustion device for smoke or exhaust gas;

2 and 3 diagrammatic representations of further arrangements of a combustion device for exhaust gas;

4, 5 and 6 are similar diagrammatic representations showing the processes to use the burned gas products in an overall system;

Figure 7 is a diagrammatic representation of a complete process heating system using the exhaust gas incinerator .

Referring to the drawings, they show a direct gas fired smoke incinerator which receives exhaust gas from a hot air chamber, which may be, for example, the hot air chamber of a metal paint plant. Figure 1 shows the combustion chamber inside an insulated casing 2, which also contains the chamber 3 of a first heat exchanger 4 and also a second heat exchanger 5, which has a preheater for fresh air or other gaseous medium starting from a suitable source, such as the outside air, for the introduction into a drying oven or similar equipment represents.

A combustion chamber 1 is divided by means of an upper horizontal divider 6 to form a duct 7 for the purpose to be described below, and further lies

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a horizontal subdivision by means of a subdivision before forming an upper chamber 9 which has a direct gas fired burner 10 with inlet 11 for the exhaust gas from the heat exchanger 4 and an outlet 12 in the lower chamber 13 in the heat exchanger 4.

In this embodiment, the process fluid is the exhaust gas that passes through to the heat exchanger before it is supplied to the combustion chamber .

The exhaust gas coming from the hot air chamber is passed through a line 14 by means of a fan 15, the The impeller of the same is located in the line or is arranged entirely in the line. The outlet of the fan housing or the conduit containing the fan is passed through a closed circuit 16, follows a bound one Path through chamber 3 and then enters chamber 9 through inlet il.

The exhaust gas entering the chamber 9 passes through the ignition device 10, where the combustible component of the exhaust is burned and the odorous products into odorless products burned or transformed. The gases coming out of the burner including the converted exhaust gas circulate around the End of the subdivision 8 into the lower chamber 13 and from the opening 12 into the chamber 3, where the same in an indirect Heat exchange ratio flow with the exhaust gas in the line and then emerge from the chamber 3 through an opening 18 into line 1.

There is a catalyst element 9a in the combustion chamber and leads to a reduction in the temperature required for combustion. The catalyst can be any suitable product, for example a metal oxide, such as chromium or vanadium oxide, or it can be a product in the form of a metal arranged on ceramic , such as platignum.

109885/1641

Where the second heat exchanger 5 is used, it has the same a chamber 19 with an inlet 20 through which the gas medium flowing in the line 1 enters and flows into a heat exchange ratio through the line 21, as explained further below, and then from the chamber 19 through an opening 22 out and into a chimney - not shown - for the purpose of discharge to the outside air.

Fresh air or other gas medium is fed into the heat exchanger line 21 for use in another of the combustion apparatus assigned plant introduced. The fresh air is provided by a fan 23, which is similar to the fan 15 can be carried out, pushed through the line 21 and then through the line 24 leaving the chamber 10. It takes place then a transfer to the oven or other hot air system.

Referring to Figure 2, there is shown the combustion chamber 25 together with the heat exchanger 3, with a gas flow arrangement similar to that of Figure 1 is present. In this embodiment there is no fresh air heat exchanger before, rather, the gas coming from the line 1 passes through a chimney, not shown, to the outside air after the process fluid has been heated, which in turn is the exhaust gas entering.

An optional embodiment is shown in Figure 3, where the combustion chamber 25 together with the fresh air preheater is applied. The burned exhaust gas coming from 25 passes through a modified line 1 a into a heat exchanger 5 and is then discharged to the outside air via a chimney - not shown. A fan 23 similar to the fan 15 pushes a supply of fresh air or similar medium through the preheater line 21 and then to the hot air chamber or the like Plant through line 24.

109885/1641

With reference to FIG. 4, there is shown an arrangement of the plant using that explained in FIG Combustion equipment along with a paint oven 40. In this system, the preheated Fresh air from <fer line 24 directly to the furnace heater 30 using the feed fan 41. 'That from the hot air chamber Exhaust gas coming from flows through line 14 to combustion device 42, as described above, Anyway, the burnt gas emerging from outlet 22 * - shaped products by means of adjustable slide 31,32 either via a chimney - not shown - to the outside air or optionally fed back to the hot air chamber or the like as recirculated air to the feed side of the heater 30 will.

In this way, the hot burned gas products can be used for heating the hot air chamber.

During the start-up phase of the system, the adjustable slides 31, 32 can emit the exhaust gases to the outside air, whereby the purge the entire system before igniting the burners in the combustion chamber. After the flushing process is complete, you can the adjustable slides 31 are then moved so that the burned gas products are returned to the paint oven are performed taking advantage of their heat.

In the embodiment shown in FIG Exhaust gas flowing through pipe 14 has a temperature of about 175 ° C, while the temperature in compartment 9 is in the combustion chamber amounts to about 650 to 815 ° C, so that the exhaust gas present in line 16 to a temperature of about 415 C is brought through the inlet 11 before entering the chamber 19. After the heat has been transferred to the exhaust gas in the pipe 16 in the chamber 3, the temperature of the exhaust gas flowing through the line 1 is reduced to about 415 ° C. and the same occurs thus in the chamber 19 at a temperature of 415 ° C and from here it transfers heat to the gaseous medium in line 21 while increasing the temperature of the same

the chimney with e

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175 ° C and then leaves the chimney at a temperature of about

It thus results / that by means of the heat exchanger according to the invention it becomes possible to minimize the amount of fuel burned at the ignition device 10 to maintain that the sensible heat present in the exhaust gases coming from the chamber 25 is applied to the exhaust gas heat before it is subjected to the action of the ignition device 10 and continue to preheat the air, which is supplied from the outside air to the hot air chamber or other system.

As such, the combustion chamber is designed to be at a sufficiently high temperature for the required "Residence time" of the exhaust gas present therein is operated during its passage, so as to prevent exhaust gas connections from escaping to hold back and in particular to remove odor components and all toxic elements from the exhaust gases. A suitable one Burner for use in the combustion chamber is a burner known under the trade name COMBUSTIFüME, however, any other suitable burner can also be used.

The combustion chamber is preferably made of an alloy steel that can withstand the working conditions, which result from the gas combustion, it being possible for the chamber to be lined if necessary. A corresponding one Access for cleaning purposes such as removable doors and covers are provided in the combustion chamber and the heat exchangers. Such access enables easy maintenance of the interior of the chamber.

With regard to the given temperature examples of the gaseous medium flowing through the various conduit chambers, the length of the combustion chamber is of course calculated in such a way that a suitable "residence time" results.

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Such a dwell time would amount to 0.25 to 1.0 seconds preferably 0.5 to 0.75 seconds, with a gas velocity of 1.5-8 m / sec resulting and preferably to 3-7 m / sec. amounts to. In the example given here with a dwell time of 0.75 seconds and a gas velocity of 7 m / sec. the length of the combustion chamber is 4.5 m.

The preheating chamber 4 is designed in such a way that blocking of the exchanger surface by hot air chamber exhaust gas which is present during the preheating phase is prevented. Either or both of the preheat chambers can be separated from the combustion chamber so that they can be separated for maintenance or assembly for operation. In the above temperature example of the working phases, the preheating chamber represents an output of 1.07 χ 10 Kcal / h, when handling an exhaust gas quantity of about 260 m / min. The temperature drop across the temperature exchanger on the hot gas side is nominally 650 to 415 ° C with a gas flow of 260 m ³ / min.

The heat exchanger 5 for use in the above temperature example in the combustion chamber is designed so that a heat transfer from the released gases to the fresh air of of the atmosphere flowing through the line 21 to a temperature rise of 21 to 175 C with the handling of 296 m / min. Fresh air leads. This represents an output of 0.8 10 Kcal / h and the temperature drop across the heat exchanger at the hot gas side amounts to 400 to 235 ° C when handling

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a gas flow rate of 260 m / min.

Suitable thermocouples or the like. Devices are provided in the chambers, some of them with corresponding Control devices and the electrical power supply to the fan motors are in communication, so as to be a corresponding Control of the entire system during operation. Further control elements are also provided so that the

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required temperature of the fresh air supply to the hot air chamber or other investments.

Provision is also made to flush the incineration equipment and ensure the required temperatures inside the incinerator prior to start-up and during work interruptions.

A sampling device or similar arrangement is preferred in the fireplace equipment in order to measure and / or record the efficiency of the combustion process. It it can be shown that - the efficiency of this device is about 85%, not taking into account the amount of heat, which comes from the combustible parts of the paint that are present in the discharged air.

Figures 5 and 6 show a further arrangement of the invention Combustion device used as an integral part of an industrial process. the FIG. 5 shows a system operating with constant volume and variable temperature, with the method 50 being mediated an exhaust fan 51 of the hot air chamber is drawn off and supplied to the combustion device 52. The from the combustion device coming hot combustion products are then passed through an indirect exchanger 53 Heating a process fluid in the form of fresh air, which is sucked in by the fan 54, and the burned exhaust gas is then via the line 55 to the outlet fed.

The hot air coming from the heat exchanger flows through a high speed conduit 56 and is submitted to the method 50 fed via two inlets 57 and 58.

Before entering the process, the hot air passes over the terminal Reheaters 59 and 60 controlled to bring the air to the required temperature.

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6 shows a system similar to that according to the Figure 5, however, results in air of variable temperature at a constant volume by means of a two-pipe arrangement 65 and 66, which takes the place of the terminal reheaters according to FIG. There is fresh air through the fan 67 is sucked in and mixed with the hot gas flowing through the line 56 in the direct heat exchangers 68 and 69. The mixed gases are then fed to process 50.

The temperature at inlets 57 and 58 is determined by the volume the fresh air mixed in the heat exchangers 68 and 69 is controlled and this volume is in turn controlled by actuation of the fan 67 and the slide 70 and 71 are controlled. The advantage of this system is that the temperature of the occur Air can be controlled without changing the volume added to the process. When the volume of incoming air is not is critical, the double-line mixing arrangement 65 and 66 can be replaced by an arrangement of simple flap valves, which change the temperature of the incoming air by increasing or decreasing the volume. The one in the figure The apparatus shown is with a direct heat exchanger or mixer 72 instead of the indirect heat exchanger 54 of FIG Fig. 5 is provided and an overflow valve is also provided.

Depending on the intended use of the process fluid it will be understood that in each of the devices described above, an indirect or direct heat exchanger can be applied.

The device shown in Figure 5 is in the complete Process heating system according to Figure 7 applied. The two processes 50 are operated with process fluid in FIG In the form of hot air from the heat exchangers 53 as described above, and in the two processes excess heat not applied enters line 80. A portion of air from line 80 travels along line 81 " down and through the heat exchanger tubes 82 where a

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Use for heating solution process 83 occurs. The remainder of the hot gases passing through lines 84 and 85 flows is through air mixing rings 86 and 87 in the air heater 88 and 89 respectively. The air can then be used, for example, to heat work rooms.

Additional heaters 90, 91 and 92 are planned, which supplement the supply of hot air for particularly strong requirements, and these heaters can, if necessary, be switched into the working group individually.

In the processes described above, drying equipment, Equipment for baking paints, equipment for heating solutions and equipment for heating applied by air and water. It can be seen that the entire process, including the one that hinders air pollution Arrangement as described above costs practically the same as, but does not, a conventional heating method Provides treatment of the exhaust gas.

Furthermore, the operating costs of the system can be very significant compared to a conventional system using more independent Heater and / or process heater can be reduced.

It should be noted that the process fluid can be any one May be gas or liquid which must be heated for use in the industrial process.

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Claims (15)

- 14 claims '1 .j apparatus for the burning of originating from an industrial process waste gases, a Verbrennungskainmer, an inlet conduit in the combustion chamber for the exhaust gas, a direct ignition device in the combustion chamber, on which is allowed to the exhaust gas flow, and an outlet in the Verbrennungskainmer for removing the burned exhaust gas, characterized in that the device has a heat exchanger (4) through which the burned exhaust gas and a process fluid are passed in a heat exchange ratio for the purpose of heating the process fluid. 2. Apparatus according to claim 1, characterized in that the exhaust gas through the combustion chamber by means of a fan (15) including a fan wheel arranged in the inlet line (14). 3. Apparatus according to claim 1 or 2, characterized in that the direct ignition device (10) is a gas burner or high-temperature electric furnace is. 4. Device according to one of the preceding claims, characterized in that the combustion chamber (9) has a catalyst (9a) for lowering the temperature in the combustion chamber at which the exhaust gas is burned. 5. Device according to one of the preceding claims, characterized characterized in that an arrangement (31,32) for interrupting the flow of the unburned exhaust gas to the combustion chamber and admitting fresh air to the same for the purpose of purging the combustion chamber of exhaust gas. 6. Device according to one of the preceding claims, characterized in that the exhaust pipe has a gas sampling device for the purpose of continuous monitoring of the composition of the burned exhaust gas. 7. Device according to one of the preceding claims, characterized in that the process fluid is the exhaust gas which is fed to the inlet duct of the combustion chamber. 8. Apparatus according to claim 7, characterized in that a second heat exchanger (5) downstream of the first heat exchanger is provided through which the burned exhaust gas is passed. 9. Device according to claims 1 to 6, characterized in that that the process fluid is fresh air and the heat exchanger is an indirect heat exchanger (53). 10. Device according to claims 1 to 6, characterized in that that the process fluid is fresh air and the heat exchanger is a direct heat exchanger (72) in which the burned exhaust gas is mixed with the fresh air. 11. Device according to claims 9 or 10, characterized in that that the process fluid is passed over terminal reheaters (59, 60) before use in the industrial process. 12. Device according to claims 10 or 11, characterized in that that an arrangement (65,66) is provided for the mixing of fresh air with the process fluid, after the process fluid has passed through the heat exchanger. 13. Device according to one of claims 9 to 12, characterized in that that the process fluid is passed through heat exchange tubes (827 and for heating a liquid is applied. 14. Device according to claims 9 to 13, characterized in that that the process fluid is used for heating air. 15. Device according to one of claims 9 to 14, characterized in that that the device has an additional fresh air heating arrangement (90,91,92) for the completion of the process fluid having. 109885/1641