RU2272158C1 - Multistage cyclone converter - Google Patents

Abstract

FIELD: mechanical engineering; compression ignition internal combustion engines.

SUBSTANCE: proposed converter has housing with twin walls with heat insulation in between, end face cover, inlet and outlet ports, reactor with exhaust gas catalytic cleaning unit and cross partition with holes. Solid particles filter is placed in reactor. Exhaust gas catalytic cleaning unit is made of coaxial porous permeable cermet oxidizing and reducing blocks installed on cross partition over solid particles filter. Housing is cyclone provided with upper cylindrical, middle conical and lower parts. Lower part consists of conical envelope. Inlet port furnished with inlet branch pipe has tangentially expanding cut into housing reaching inner walls of housing. Device to remove solid particles is provided.

EFFECT: improved cleaning of exhaust gases, simplified design of converter.

1 dwg

Description

The invention relates to mechanical engineering, namely to engine building, and can be used for purification of exhaust gases of internal combustion engines with compression ignition.

Known catalytic converter for exhaust gases of an internal combustion engine, comprising a housing with double walls, heat insulation between them, end caps, inlet and outlet windows, a heat exchanger, a reactor, a limited device for primary purification of exhaust gases from solid particles and equipped with a catalytic exhaust gas treatment unit, as well transverse partitions with holes. The inlet window of the heat exchanger is communicated with a heater, the exhaust pipe of which is placed along the axis of the housing and connected to the outlet window of the heat exchanger. The end part of the exhaust pipe of the heater is perforated and located inside the catalytic exhaust gas treatment unit, which is a fluidized bed catalyst. The device for primary purification of exhaust gases from solid particles is limited by the internal walls of the vessel, by the outer surface of the reactor with a heat exchanger and performs the function of an inertial stage for cleaning exhaust gases from solid particles around the reactor integrated in the vessel (see USSR author's certificate No. 1188344, IPC F 01 N 3/28 Publ. 1985).

The main disadvantage of the described exhaust gas catalyst of an internal combustion engine is the low degree of purification of exhaust gases, firstly, due to the breakthrough of solid particles through the fluidized bed of the catalyst, and secondly, due to the lack of selective purification of exhaust gases in individual stages of neutralization.

Also known is a cyclone exhaust gas converter of a multi-cylinder internal combustion engine equipped with exhaust pipes, comprising a housing with double walls, heat insulation between them, an end cap, inlet and outlet windows, a reactor limited to a device for primary purification of exhaust gases from solid particles and equipped with a catalytic unit for exhaust treatment gases, as well as transverse partitions with holes that are simultaneously the input and output gratings. The Converter further comprises a pulse Converter, made in the form of series-connected confuser, a mixing chamber and a diffuser, a resonator and a connecting pipe. The diffuser is connected to the inlet window, and the confuser is in communication with the exhaust pipes through the connecting pipe. The internal cavity of the connecting pipe is divided into channels by the number of exhaust pipelines. An opening is made on the side surface of the connecting pipe. The resonator is made in the form of a casing covering the connecting pipe with the formation of a chamber in the area of the hole. A fluidized bed catalyst was used as a catalytic exhaust gas cleaning unit. The device for primary purification of exhaust gases from solid particles is limited by the inner walls of the vessel, the outer surface of the reactor and performs the function of the inertial stage of purification of exhaust gases from solid particles around the reactor integrated in the vessel (RF patent No. 20133580, IPC F 01 N 3/28, publ. 1994) .

The main disadvantage of the exhaust gas catalytic converter of a multi-cylinder internal combustion engine is the low degree of exhaust gas purification due to the lack of multi-stage selective exhaust gas purification from incomplete combustion products, particulate matter and nitrogen oxides.

The objective of the invention is to increase the degree of purification of exhaust gases and simplifying the design of the converter.

The problem is solved in that in a converter containing a housing with double walls, thermal insulation between them, an end cap, inlet and outlet windows, a reactor equipped with a catalytic exhaust gas purification unit, a particulate filter made in the form of a porous permeable cermet block is introduced into the reactor and the catalytic treatment unit is made of coaxial porous permeable metal-ceramic oxidizing and reducing catalytic units mounted on a transverse partition e above the filter of solid particles, while the housing has parts: the upper one is in the form of a cylinder, the middle one is in the form of a cone and the lower one consists of a conical shell.

The invention is illustrated in the drawing, which shows an axial longitudinal section of a cyclone multistage converter. In the drawing, the direction of movement of the exhaust gases inside the cyclone is additionally indicated by arrows.

The converter contains a housing 1 with double walls: external 2 and internal 3, thermal insulation 4 between them. The upper part of the housing 1 is made in the form of a cylinder, the middle - in the form of a cone, the lower - also in the form of a conical shell. The inlet window, provided with an inlet pipe 5 with a flange 6, has a tangentially expanding insert 7 in the housing 1 to the inner walls 3. The housing 1 is a cyclone. A reactor 8 is located in the cavity of the housing 1. The reactor 8 is held on the upper end cap 9 with a stamped annular bonnet 10 for centering and fastening. The end cover 9 is mounted on the flange 11 of the housing 1. The walls of the cover 9, facing the reactor 8, and the inner walls of the latter form the cavity of the reactor neutralizer. A transverse baffle 12 is installed in the reactor cavity with a stamped annular bonnet 13, through holes 14 and a spacer collar 15. A particulate filter is integrated in the lower conical part 16 of the cyclone, made in the form of a porous permeable metal-ceramic honeycomb-segment catalytic block 17 with end walls lower 18 and top 19. Above the particulate filter on the annular bonks 13 of the septum 12 and the annular bonks 20 of the end cap 9, coaxial ribbed porous permeable metal-ceramic oxidizing catalytically unit 21 and a porous cermet permeable catalytic reduction unit 22, a block forming the catalytic purification of exhaust gases. An outlet window is provided for the outlet of the purified gases, provided with a nozzle 23 with a flange 24 on the cover 25, held together with the cover 9 on the flange 11 of the housing 1. In the cover 9, a through window 26 is made. The lower part of the housing 1 consists of a conical shell 27 forming an inner surface with a grid 28 with conical holes 29 and a device 30 for removing solid particles from the cavity 31 to collect the latter. The end walls 18 and 19 are made with alternating holes 32 and 33 and are separated by porous permeable cermet walls 34 with the formation of a porous permeable cermet honeycomb-segment catalytic block 17.

The volume of the reactor with a porous permeable cermet honeycomb segment catalytic unit 17 and a catalytic exhaust gas purification unit is divided by partitions and block walls into separate cavities: cavity 35 of the particle filter, cavity 36 of the exit from the filter of solid particles, cavity 37 of the entrance to the porous permeable cermet oxidative catalytic block 21, a cavity 38 of exit from block 21 and an entrance to a porous permeable cermet reduction catalytic block 22, cavity 39 of exit from block 22, p Pit 40 of gas expansion. A cyclone cavity 41 is formed between the inner surface of the wall 3 of the housing 1 and the reactor 8, and an exhaust gas turning cavity 42 is formed between the grate 28 and the lower conical part 16 of the reactor.

Cyclone multistage Converter operates as follows. The exhaust gas of the diesel through the inlet pipe 5 through the inset 7 enter the cavity 41, wash the reactor 8 in a spiral. In this case, the solid particles belong to the inner surfaces of the wall 3. The gas passes from the cavity 41 into the cavity 42 at an angle of more than 90 degrees and is directed through the cavity 42, walls 34 of the block 17 into the cavity 36. Rough cleaning of gases from solid particles is carried out by cyclone flow, and thin - filtering in block 17.

Then the gases through the window 14 are sent to the cavity 37, through the porous permeable cermet oxidizing catalytic block 21 to the cavity 38. At the same time, in the block 21, carbon monoxide and hydrocarbons bind free oxygen from the exhaust gas composition. This allows the next stage of cleaning - the reduction of nitrogen oxides during the passage of gases from the cavity 38 through the walls of the porous permeable cermet reduction catalytic unit 22 to carry out a more complete reduction of nitrogen oxides to nitrogen and oxygen. From the cavity 39, the gases are directed to the cavity 40, and then through the pipe 23 are discharged from the converter.

This embodiment of the cyclone multistage catalyst provides a reduction in emissions of solid particles by 93 ... 95%, carbon monoxide and hydrocarbons - by 70 ... 75%, nitrogen oxides - by 65%.

Claims (1)

A catalyst containing a double-walled housing with thermal insulation between them, an end cap, inlet and outlet windows, a reactor equipped with a catalytic exhaust gas treatment unit, characterized in that a particulate filter made in the form of a porous permeable cermet block is introduced into the reactor, and the unit catalytic purification is made of coaxial porous permeable metal-ceramic oxidizing and reducing catalytic blocks mounted on a transverse baffle above the filter breathing particles, while the body has parts: the upper - in the form of a cylinder, the middle - in the form of a cone and the lower, consisting of a conical shell.