DE2723685A1 - Cracked gas generator for catalytic fuel gasification - with atomised fuel sprays on porous plate upstream of catalyst package - Google Patents

Abstract

A cracked gas producer is used for the catalytic conversion of atomised or gasified liquid fuel in a catalyst chamber. The narrow end of a divergent tube leading to the catalyst package is covered by a porous plate against which the fuel is sprayed; the tube itself is equipped with a spark plug. Primary air is introduced to the inlet side of the porous plate from a metering device. Fuel supply for internal combustion engines with a minimum of toxic components in the exhaust gases. Creates a very compact unit, suitable for motor cars, including a catalyst chamber, mixer, distributor and starting aid.

Description

Cracked gas generator for the catalytic conversion of liquid

Oxygen-Containing Gas Fuel The invention relates to a gap gas generator for the catalytic conversion of sprayed, evaporated or gasify liquid fuel with an oxygen-containing gas at increased Temperature in a fuel gas, where the cracked gas generator has a catalyst chamber, an inlet pipe widening in the shape of a funnel to the cross section of the Xainer on one side End of the catalyst chamber, a distributor arranged in the inlet pipe, a gas-permeable filling the flow cross-section in the vicinity of the enlarged inlet pipe end Cover plate, a catalyst filling downstream of the cover plate in terms of flow and an outlet at the other end of the catalyst chamber.

In so-called gap gas generators are sprayed, gasified or vaporized liquid hydrocarbons with an oxygen-containing gas, for example Air or exhaust gas, at elevated temperatures, into a carbon monoxide, methane and / or Hydrogen-containing fuel gas (cracked gas) implemented.

This fuel gas can, for example, be mixed with combustion air and used in internal combustion engines or burners.

While e.g. when feeding liquid fuel into motor vehicle engines the imperfect evaporation of the fuel and the uneven mixing old Combustion air to incomplete combustion and emission of pollutants, the cracked gas is burned largely without residue. There It also has a high octane rating and can also be used with anti-knock agents be waived. The content of hazardous substances in the exhaust gas from incineration facilities, in particular internal combustion engines, is significantly reduced as a result.

In the not previously published German patent application P 25 58 922.4 a gap gas generator is proposed, the catalyst chamber on one End of an inlet with a funnel-shaped widening to the cross-section of the chamber Inlet pipe and at the other end has an outlet which into the cavity of a The double-walled jacket surrounding the chamber opens and has an outlet nozzle connected is. Near the enlarged end of the inlet pipe is one of the Gas-permeable cover plate filling the chamber cross-section is provided to which A catalyst filling follows in the flow direction.

As a cover plate is a porous ceramic plate with a variety Suggested through channels evenly distributed over the plate surface, whereby the incoming mixture of the fuel to be converted and the oxygen-containing Gas is distributed over the chamber cross-section. The enema substances that are about the tighter Opening of the inlet pipe to be introduced into the gap gas generator, buses if possible be distributed evenly over the entire cross-section of the chamber, so that the catalyst filling is equally busy. For this purpose it is proposed that a suitable ii inlet pipe be used Arrange distributors.

A distributor for a gap gas generator is in the German Offenlegungsschrift 24 39 144. It is funnel-shaped in one that is open at both ends widening cladding tube at least one of a plurality of parallel passage channels interspersed plate arranged perpendicular to the cladding tube axis. Parallel for this plate there is an opening in the enlarged opening of the cladding tube filling, also penetrated by a large number of parallel passages End plate provided. Between the edge of the first plate and the cladding tube are also practically along the entire edge of the plate through slots intended.

For the operation of a cracked gasifier, apart from the catalyst chamber and a distributor, further additional equipment is required, e.g. a starting device, when starting the cold gap gas generator to the increased operating temperature to bring a device for spraying or vaporizing the liquid fuel and a fuel / air mixer. Furthermore, heat exchangers are used to heat the oxygen-containing Gas (e.g. gasification air) and for cooling the generated fuel gas before it is fed in in an internal combustion engine advantageous. The complete system for the production of the Fuel gas therefore not only requires a considerable construction volume, which e.g.

makes installation in the engine compartment of motor vehicles difficult, but also considerable time spent on manufacture and maintenance.

The invention is based on the object of providing a compact as possible Specify arrangement for a gap gas generator, which has a catalyst chamber, a Contains mixer and distributor as well as a starting device.

To solve this problem it is proposed according to the invention, in a gap gas generator of the type specified above, the narrower opening of the To connect the inlet pipe with an adjustable air supply, as a distributor in the widening inlet pipe fills practically the entire flow cross-section Provide porous plate in the inlet pipe a porous in the direction of flow on this Plate-directed, controllable fuel inlet to arrange spray nozzle and attaching an igniter between the porous plate and the cover plate.

In this arrangement, the funnel-shaped inlet pipe is used with the porous plate on one side, the gas-permeable end plate on the other Opening and the fuel injector simultaneously as a mixer, distributor and Boot device. Furthermore, the housing of the arrangement can be designed such that favorable flow conditions, a preheating of fuel and / or oxygen-containing Gas, thermal insulation of the catalyst chamber and cooling of the fuel gas produced, e.g.

before feeding into internal combustion engines, with little equipment Effort can be achieved.

The essence of the invention, further advantageous embodiments and The advantages that can be achieved therewith are illustrated with the aid of a figure and a preferred exemplary embodiment explained in more detail.

The schematic figure shows the basic structure of such a Cracked gas generator in longitudinal section. With 1 a catalyst chamber is referred to, which is a cylindrical pipe section 2 open on both sides with a gas-permeable Cover plate 3 at one pipe opening (inlet) and a gas-permeable end plate 4 at the other pipe opening (outlet). The catalyst filling is between these plates 5 packed, for example a bed of ceramic, with catalytic substances impregnated moldings.

Strönungamäßig in front of the cover plate 3 is a look at the cross section The inlet pipe 6 expanding the catalyst chamber is arranged. Perpendicular to the axis of the Eiflaufrohres is in the vicinity of the narrower inlet opening via a Rohrsttick 7 a attached to the porous plate 8, which extends to the vicinity of the wall of the inlet pipe 6. Advantageously, slot-like runs practically around the entire edge of the porous plate By- outlet openings 9, which form a flow path along the inlet pipe wall open. A directed onto the porous plate 8 also protrudes axially into the inlet pipe Fuel nozzle 10, through which practically the entire area of the porous plate 8 can be sprayed with fuel. The porous plate 8 is fluidically one further gas-permeable plate 11 upstream, which surrounds the nozzle 10 in an annular manner and closes the inlet pipe upstream. The one in the inlet pipe 6 from the plates 3 and 8 formed cavity 111 serves as a mixing and distribution space during continuous operation and also as a combustion chamber during starting. This is on the inlet pipe between the porous plate 8 and the cover plate 3 an ignition device, preferably one electric spark plug 12, arranged.

The housing of the arrangement is designed so that a double-walled Jacket for the catalyst filling 5 is created.

For this purpose a funnel-shaped widening, coaxial, the inlet pipe 6 surrounding outer pipe 13 is provided, which with the inlet pipe a forms annular cavity 15 open towards the inlet opening of the inlet pipe. The catalyst chamber is coaxially surrounded by a lower housing part 16 in such a way that one connected to the catalyst chamber 1 via the gas-permeable end plate 4 Shell cavity 17 is created.

The oxygen-containing gas (e.g. air) is shown according to the arrows 18 by means of an air supply, which a (not shown) metering device contains, from the opposite side of the injection nozzle 10 axially of the assembly fed and via a pipe system 19 through the jacket cavity 17 through into the Cavity 15 passed. The pipe system 19 is opposite the cavity 15 by a annular gas-permeable body 20 separated.

To discharge the fuel gas obtained, proceed according to the arrows 21 from the catalyst chamber 1 through the End plate 4 in the Jacket cavity 17 flows, a discharge pipe 22 is used, which from the jacket cavity drive out and the supply of the oxygen-containing gas 14 encloses concentrically. In the jacket cavity 17, at least one intermediate wall 23 is also provided, which the jacket cavity into several annular channels connected one behind the other in terms of flow divides and is designed so that the cracked gas formed in the rammer initially directed from the chamber outlet along the outside of the pipe section 2, deflected and finally passed on the inside of the housing outer wall 16 to the discharge nozzle 22 will.

The gap carburetor is advantageously designed so that the binlaut tube 6 and the tube 13 coaxial therewith forms a removable cover and the catalyst chamber 1 is accessible from the outside. The catalyst filling is advantageous as a cartridge formed, which consists of the pipe section 1, the cover plate 2, the end plate 3 and the catalytic converter filling 4 and, for example, easy as part of normal maintenance work can be exchanged. This cartridge can by feet or webs 23 in the housing being held.

The operation of the gap gas generator described is now for the case explains that in it low-octane raw gasoline with gasification air to a high-octane Fission gas for the low-pollutant operation of internal combustion engines are exposed target.

Around the initially cold gap gas generator and the internal combustion engine to start, is first via the injection nozzle 10 gasoline ait @@ nem opposite the Continuous operation low throughput (e.g. 1 1/2 to 2 1 / hour) injected, which distributed over the pores of the porous plate 8. At the same time, the at the nozzle 22 connected internal combustion engine started, the air now through the arrangement sucks. The metering device in the air supply is so bessen that the Air ratio (i.e. the ratio of the intake Gasification air to the air required for stoichiometric combustion of the injected gasoline) is approximately between 0.3 and 0.5. The air decreases as it flows through the porous plate 8 with the distributed fuel, with an ignitable in the adjoining mixing chamber 111 The result is a mixture which is ignited by the spark plug 12. The resulting flame strikes back on the porous plate 8.

The porous plate 8 serves as a burner plate for flameless combustion of the fuel / air mixture. She. can be made of porous ceramic (e.g. magnesium oxide) consist and a plurality of open passage channels (24), e.g. about 40 to 60 passages per cm2 of plate surface with a diameter of about 1 mm. The burner plate 8 heats up so much that the gasoline / air mixture is already in the plates when flowing through the pores and passage channels 24 above the combustion temperature is heated up and burned out. It then finds a flameless, largely soot-free combustion takes place at high temperature. The resulting hot flame gases are sucked by the internal combustion engine through the catalyst filling 5 and heated this quickly. Because of the severe lack of air during combustion on the porous plate 8 the flame gases still contain so much flammable substances that the internal combustion engine already at the time of ignition on with the generated flame gases and others sucked in Combustion air can be numbed at least when idling and keeps going.

After a few seconds, the catalyst filling has that for the catalytic one Implementation required operating temperature is reached and it can be switched to higher performance will. To do this, the gasoline throughput is increased and the air ratio is reduced to 0.1, for example. At these throughputs, there is no significant combustion on the porous plate 8 Instead, it is now the gasoline / air mixture in the catalyst filling that is now hot 5 catalytically converted. The resulting fuel gas has because of the low air ratio provided for continuous operation has a particularly high calorific value. It is particularly advantageous if the additionally required gasoline is used during load operation Via injection devices 25, which are arranged on the cavity 15, directly to the hot inlet pipe 5 is sprayed and instantly evaporated. The cavity 15 serves as a mixing space for the vaporized gasoline and the gasification air. The porous body 20 prevents vaporized fuel from going upstream enters the pipe system 19 and forms an explosive mixture there.

The further gas-permeable plate 11 also serves in a similar manner as a kickback protection for the sprayed through the nozzle 10 onto the porous plate Mixture as long as this plate acts as a burner plate during start-up. as well the gas-permeable cover plate 3 prevents kickback during continuous operation the reaction from the catalyst filling into the mixing space 111.

The plates 3, 8 and 11 also act as a distributor for those flowing through Currents. These plates - and also the porous body 20 and the end plate 4 - can also made of porous ceramic, e.g. magnesium oxide, and a multitude of passage channels 26 included.

They create a certain jam effect and distribute the throughput fairly evenly over the entire respective flow cross-section. About that In addition, the passage openings can each be distributed over the plate surface in this way that the gases flowing through are even more uniform over the flow cross-sections be distributed. The passage openings 9 between the porous plate 8 and the Inlet pipe 6 represent a lower flow resistance compared to the passage channels 24 and thereby force the mixture flowing through, partly on the wall of the Inlet pipe to flow along and the expansion of the pipe cross-section on the Follow the flow cross-section of the catalyst chamber.

The hot flame or flame emanating from the catalyst chamber. Cracked gas is first attached to the chamber wall (pipe section) through the partition 23 in the jacket cavity 17 2 passed along the outside and therefore keeps it at a higher temperature. This will the catalyst chamber insulates against heat dissipation to the outside. Afterward the hot gas flows in countercurrent to the gasification air along the pipe system 19, that thereby a cooling of the cracked gas (in the case of an internal combustion engine consequently a Increases the engine load) and preheats the gasification air. These The heat exchanger effect is reinforced if one increases the exchange area manufactures the pipe system from corrugated pipes.

The cooling of the fuel gas is even more effective when you use this The pipe system supplies the gasoline to be evaporated and the gasification air supply e.g. in place of the fuel injectors 25. Because some catalysts If in contact with unevaporated gasoline it should produce soot, however in these cases an evaporation of unsprayed gasoline and especially a common preheating of gasoline and gasification air in the pipe system (heat exchanger) only then made if it is ensured that the available fission gas heat is sufficient to vaporize the gasoline.

The gap gas generator according to the invention combined in a compact, space-saving arrangement a catalyst chamber and all necessary for the operation Additional equipment such as mixers, distributors, heat exchangers and starters.

13 claims 1 figure

Claims (13)

Claims 1. Cracked gas generator for the catalytic conversion of sprayed, vaporized or gasified liquid fuel with a. oxygenated Gas at elevated temperature in a fuel gas containing a catalyst chamber, a funnel-colored inlet pipe widening to the cross-section of the chamber - one Winding the catalyst chamber, a manifold arranged in the inlet pipe, a filling the flow cross-section near the enlarged inlet pipe end, gas-permeable cover plate, one downstream of the cover plate in terms of flow Catalyst filling and an outlet at the other end of the catalyst chamber, d a d u r c h e k e n n n n z e i c h n e t that the narrower opening of the inlet pipe (6) is connected to an adjustable LuttzuSUhrung that as a distributor in the expanding Inlet pipe (6) is a porous pipe that fills practically the entire flow cross-section Plate (8) is provided that ia inlet pipe one in the direction of flow on the porous plate (8) directed, controllable fuel injection nozzle (10) arranged is and that between the porous plate (8) and the cover plate (3) an ignition device (12) is provided. 2. gap gas generator according to claim 1, characterized in that between the edge of the porous plate (8) and the wall of the inlet pipe (6) along Through openings (9) distributed around the edge of the plate are provided. 3. gap gas generator according to claim 1 or 2, characterized in that that the inlet pipe (6) is surrounded by a coaxial outer pipe (13) and the resulting Cavity 15 in terms of flow between the air supply (30) and the narrower opening of the inlet pipe (6) is switched. 4. gap gas generator according to claim 3, characterized in that at least one fuel feed (25) opens into the cavity (15). 5. Gas generator according to one of Claims 1 to 4, characterized in that the fuel injection nozzle (10) through a further gas-permeable one inserted into the narrower opening of the inlet pipe Plate (11) protrudes. 6. Gas generator according to one of claims 1 to 5, characterized in that that the porous plate (8) as a burner plate, the cover plate (26) and the other Plate (11) are designed as distributor plates. 7. Gas generator according to one of claims 1 to 6, characterized in that that the inlet pipe (6) as a removable Dedul of a surrounding the catalyst chamber Housing (16) and the catalyst filling (5) is designed as a cartridge (1). 8. Gas generator according to one of claims 1 to 7, characterized in that that the housing (16) forms a double-walled jacket of the catalyst chamber (1). 9. Gas generator according to claim 8, characterized in that in the shell cavity (17) a pipe system (19) is provided for evaporating the fuel. 10. Gas generator according to claim 8, characterized in that in the Shell cavity (17) a pipe system (19) for heating the oxygen-containing gas (18) is provided. 11. Gas generator according to claim 3 and 10, characterized in that the pipe system (19) by means of a gas-permeable body (20) with the cavity (15) is connected between the inlet pipe (6) and the outer pipe (13). 12. gap gas generator according to one of claims 8 to 11, characterized in that that the side wall of the chamber (1) as one open on both sides Pipe section (2) is designed that the one opening of the pipe section to the widen Opening of the inlet pipe (6) is connected that the other opening of the pipe section forms the outlet and via a gas-permeable closing plate (4) with the mantle cavity is connected, and that a discharge nozzle (22) is arranged on the jacket outer wall (16) is. 13. Gas generator according to claim 12, characterized in that the Shell cavity (17) through at least one partition (23) in several flow-wise series-connected annular channels is divided and that the partition (23) is designed so that the cracked gas formed in the chamber initially from the outlet the chamber along the outside of the pipe piece, deflected and finally is passed along the inside of the outer jacket wall to the discharge nozzle (21).