DE3046258A1 - DEVICE AND METHOD FOR TREATING A COMBUSTIBLE SOLID PARTICLE CONTAINING HOT EXHAUST FLOW - Google Patents

Description

DR. GERHARD SCHUPFNER PATENT ADVOCATE

turupedn patent attorney

. 6th

Karlstrasse 5

D 2110 Buchhol /: in the north heath Office phone (01181) 4457 Tukjfon: Pnvat (04187) 6345 Tcilcjx 02180330 Tiilegrdmm Telepatent

December 5, 1960 S / KB

T.-053 80 DE

D 77.026-F (RBB)

TEXACO DEVELOPMENT CORPORATION

2000 WESTCHESTER AVENUE WHITE PLAINS, N.Y. 10650 U. S. A.

Apparatus and method for processing a combustible solid particle entrained hot

Exhaust gas flow

130038 / Q645

Apparatus and method for processing a combustible solid particle containing hot

Exhaust gas flow

In internal combustion engines, it is desirable to process the exhaust gases, so that they can be released into the atmosphere without hesitation. In some internal combustion engines, particularly diesel-powered ones, one of the most common problems is the presence of air entrained in the exhaust gas stream Solid particles.

The main thing is usually the particulate matter Carbon particles. They are caused by the incomplete combustion of the hydrocarbon fuel under certain engine operating conditions. However, the operating efficiency of the engine also contributes to that Amount of carbon particles generated.

The presence of relatively large amounts of carbon particles in an exhaust gas stream can be seen from the fact that a dark, smoky, undesirable discharge ensues. This smoke is not only unsightly, it can also be in large amounts can also be harmful to health.

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Devices are known to measure the solid particle content to be eliminated or kept small in exhaust gas flows. However, it has been shown that although the Solid particles with a suitably designed filter can be eliminated; however, this ultimately results in saturation and / or inoperability of the filter due to excessive build-up of particulate matter.

It is also known that the engine exhaust gas processing method can be accelerated overall, üies can be achieved by not only the hot gas flow through a filter medium is passed, but the filter is provided with a catalyst, which the combustion of the retained particles accelerated.

It should be noted that carbon particles are generated under all operating conditions of diesel engines. It should also be noted that the amount and quality of the exhaust gas flow of each internal combustion engine are corresponding to the Change the operating characteristics of the machine.

For example, the temperature range of a diesel engine between low Abgasstrorns above room temperature and fluctuate more than 649 ⁰ C. When the exhaust gas is sufficiently hot, it is collected in a filter

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Carbon particles burned. With diesel-powered However, passenger cars hardly become an engine operating condition in which this regeneration can take place achieved.

When a machine runs continuously under such conditions that the particulate matter is continuous are generated and collected in the filter, the filter bed absorbing the solid particles must back and forth can be regenerated again.

normally the regeneration consists in simply introducing the hot exhaust gas stream containing sufficient oxygen into the filter bed is passed to contact and ignite the carbon particles trapped therein or to incinerate. When burning a large and bound carbon accumulation, however Temperatures are generated that are far above those of the exhaust gas. This has the consequence that in such excessively high Temperatures the filter bed or the filter insert a thermal shock, damage or a change in shape can experience.

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The object of the invention is to create an exhaust gas preparation device and a corresponding method, wherein a filter unit separates particulate matter from the exhaust gas flow of an internal combustion engine and the filter bed can be periodically regenerated by burning the solid particles; regeneration takes place in the process during operation of the internal combustion engine under conditions in which normally none for the Combustion generated sufficient exhaust gas temperatures, and the nature of the filter bed will not endangered by thermal shock or damage.

To achieve a satisfactory or limited carbon separation from an exhaust system without damaging the filter, the device according to the invention has a Reaction space or section containing a catalyst bed through which at least a portion of the exhaust gas flow is directed. This catalyst segment can either be placed in the filter bed retaining the solid particles be integrated or upstream of this.

To ensure that the main filter bed or the main filter beds is constantly functional, the exhaust gas flow periodically and regularly heated to a temperature, ♦

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the temperature above that required to initiate combustion of retained particulate matter lies.

Physically, the heating takes place in that a desired amount of a combustible fluid is introduced directly into the exhaust gas flow is injected. This fuel mixes with the diesel exhaust gases, which contain excess oxygen. When the mixture contacts the catalyst, an exothermic reaction takes place, increasing the exhaust gas temperature at least to the combustion temperature of the carbon particles retained in the main filter bed is increased.

Thus, the main filter bed is regular in periodic Time intervals regenerated. If this treatment is repeated at predetermined time intervals, the Accumulation of carbon that would otherwise occur at the time their combustion would result in thermal stress or damage to the filter bed, avoided.

The object of the invention is thus achieved by a device and a method according to the claims.

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The invention is explained in more detail, for example, with the aid of the drawing. Show it:

1 shows a diesel engine with which the filter device cooperates; and

FIG. 2 shows a larger cross section through the filter device according to FIG. 1.

To simplify the description, it is assumed that the internal combustion engine 10 or exhaust gas source is a diesel engine. In this case, the various combustion chambers sequentially air is supplied from an air filter through a manifold 12. Then it is in each combustion chamber Fuel from a fuel pump 13 over a gas linkage 14 injected.

The hot exhaust gas flow exits the exhaust manifold 16 and passes through an exhaust pipe 18 to a smoke filter 17. A muffler could indeed be built into the exhaust pipe be, but this is not important in the present case.

After exiting the exhaust manifold 16, the exhaust gas flow has a temperature in the range of approx. 93-64-9 C. The exact temperature depends on the operating conditions

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of the engine. For example, at low engine speeds and when idling, the exhaust gas is relatively cool or only slightly heated. As a result, when the exhaust gas flow enters the filter device 17, those are carried along in the exhaust gas flow Particles in the plurality of passages in the filter bed 19 are retained.

While the exhaust gas consists primarily of a combination of gases, it usually has a sufficient one Oxygen content to sustain at least limited combustion within the exhaust stream itself.

The filter device 17 essentially comprises a long metal housing 21 with opposing end walls 22 and 23, between which an inner reaction space is formed. This will to a large extent by at least occupied a bed 19 made of a material suitable for the formation of a plurality of irregular Passages is particularly suitable.

The function of this bed or similar additional beds is to block a number of passages form through which the exhaust gas flows. During this flow, they are carried along in the exhaust gas flow Solid particles retained along the various passage walls.

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In one embodiment, the bed 19 can be made from a sieve-like metallic mass such as steel wool or the like. Are shaped so that they the Substantially fills the reaction space.

If desired, the bed 19 at its inlet and its outlet end be equipped with perforated plates 26 and 27 or other similar transverse elements. These are arranged on the wall of the housing 21 in order to support or hold the bed or more beds.

The inlet end wall 23 of the filter device has an inlet opening 28 through which exhaust gas is introduced to the inlet side of the bed 19. In a similar way is the outlet-side plate 26 with an outlet opening 29 for discharging gases leaving the bed tied together.

In order to achieve an optimal filter effect on the exhaust gas flow, the filter bed 19, as mentioned, can consist of one suitable medium that absorbs the solid particles from the exhaust gas flow. However, the subsequent To simplify combustion of the retained particles, the filter medium can have on its surface a suitable catalyst that accelerates the oxidation of fuel and the combustible particles be .

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If the filter bed 19 is used without a catalyst, there is a pretreatment segment at its front or inlet end 19a arranged. This includes a catalyst material, which can cause the desired oxidation of fuel and particulates. This pre-filter chamber 19a can be part of the filter bed 19 or a segment which is separate therefrom.

For example, the pre-filter segment 19a can be sectioned in the front of the housing 21 so that it is contacted by the incoming exhaust gases as soon as they are in enter the filter housing.

For the preheating of the exhaust gas flow, an injection system is provided, which is primarily a supply of a combustible one Fuel in connection with a unit for introducing a metered amount of the fuel into the heated Exhaust gas flow is. The fuel supply can be liquid or be gaseous in order to achieve the desired preheating function.

As will be explained below, the auxiliary fuel Be diesel fuel that is also used to drive the internal combustion engine 10 is used. Alternatively, it can be a compressed gas such as propane or the like. that only for the purpose of injection into the pre-filter chamber

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is carried. Thus, the additional fuel can be any of a number of known more volatile Hydrocarbon or other substances capable of reacting in the catalyst chamber.

The injection system comprises a pump 31 or another suitable metering unit, the inlet side 32 of which with the Fuel supply 13 is connected. The pump 31 is in turn connected to an injection nozzle 33, the one or a plurality of outlet openings 37, which are located at the front end of the pre-filter chamber containing the catalyst 34 are arranged.

When the pump 31 periodically from an injector actuator 36 is actuated, a metered amount of the combustible atomized fuel goes directly into the Pre-filter chamber 34, in which it is through contact with the ignited heated exhaust gas in the presence of the oxidizing catalyst.

In order to achieve the periodic heating of the exhaust gas, the actuating unit 36 for the pump 31 is specially designed in such a way that that the pump is operated at regular preset times. These time intervals can be either on can be determined based on the mileage of the engine or the actual operating time of the engine.

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Further actuation can be a function of the temperature be in the filter insert. In any case, the timing of the injection process should achieve that regardless of the engine operating conditions, the carbon particles periodically in the filter device to be incinerated. The intervals between the time intervals are dimensioned so that even under the most unfavorable engine operating conditions an excessive Accumulation of carbon particles is avoided.

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Claims (14)

Claims 1. Device for processing a combustible solid particle entrained hot exhaust gas flow, with - at least one filter unit comprising: - a reaction space with an inlet opening connected to an exhaust gas source, and - A main filter bed positioned in the reaction space for contacting and retaining solid particles from the exhaust gas flow flowing through, marked by - A pre-filter bed arranged in front of the main filter bed (19) (3A-) with a catalytic filter medium, - an injection unit with an injection metering member (31), its inlet (32) with a supply of a combustible fluid (13) and its outlet opening (33) with the pre-filter bed (34) is connected, and - An injection control unit (36) which is adjustably connected to the injection metering member (31) and this operated at certain time intervals, so that a metered amount of the combustible fluid in the pre-filter bed (3A-) is injectable, 130033/0648 - whereby injected fluid in the pre-filter bed (34-) ignited and thus the temperature of the exhaust gas flowing through the pre-filter bed (34) above the ignition temperature of the combustible solid particles is increased. 2. Device according to claim 1, characterized in that - that the pre-filter bed with the main filter bed (19) is made in one piece. 3. Device according to claim 1, characterized in that - that the pre-filter bed is connected to the main filter bed (19) adjoins. 4. Device according to one of claims 1-3, characterized, - That the metering member (31) is connected to a liquid fuel supply. 5. Device according to one of claims 1-3, characterized in that - That the dosing member (31) is connected to a pressurized gas supply. 13Ö03S / 064S 6. Apparatus according to claim 5,
characterized, - that the gas is propane. 7. Device according to one of claims 1-6, characterized in that - That the injection control unit (36) has a clock contains, which switches on the injection metering member (31) at predetermined time intervals. 8. Device according to one of claims 1-6, characterized in that - That the injection control unit (36), the injection metering member (31) at predetermined exhaust gas temperatures turns on. 9. Process for processing a flue gas stream carrying flammable solid particles, characterized by the following process steps: - Directing the exhaust gas stream into a filter bed so that at least a portion of the particulate matter is retained therein will, - Periodic heating of at least a portion of the exhaust gas before it enters the filter bed to a 130038/0645 above the ignition temperature of the retained combustible Solid particle temperature, and Directing the heated exhaust gas into contact with the filter containing the particulate matter for combustion the solid particles. 10. The method according to claim 9, characterized in that - That in the gas heating step a certain amount of a combustible fluid in the exhaust gas stream before it Entrance into the filter bed is injected. 11. The method according to claim 10, characterized in that - That a liquid fuel is used as the combustible fluid will. 12. The method according to claim 11, characterized in that - That the combustible fluid is diesel fuel. 13. The method according to claim 10, characterized in that - That a gaseous fuel is used as the combustible fluid. 130038 / 064S 14. The method according to claim 13, characterized in - that the combustible fluid is propane gas. 130038 / 064S