RU1776837C - Exhaust gas converter - Google Patents

Abstract

Usage: in the construction industry. namely, in devices for cleaning cuts 7 and -: 15 ... fallen gases of engines with compression ignition. The inventive neutralizer contains a housing (K), which consists of the upper part of the housing (VChK) 1 and the lower part of the housing (LFK) 2. In K there is a reaction chamber (PK) 3 with a fluidized bed of catalyst 17. In the LFK 2, a perforated pipe (PT) 9 is fixed with holes 10 and 23. Entrance grate in RK 3 is made in the form of a porous metal-ceramic block (MKB) 18 and is fixed with a collar 19 of VChK 1. (PT) 0 is inserted into MBK 18 and holes 10 are blocked by ICD 18. Between the walls K and RK 3 there is a thermal insulation 4. PT 9 serves to supply gas to the reaction zone, for example ep ammonia. 1 ill. v | v | About 00 CA V | uutuuuuu u ".uuuuuuuu uu - u; .- "q v.

Description

The invention relates to mechanical engineering, in particular engine manufacturing, and can be used to clean the exhaust gases of compression ignition engines.

Multistage catalytic converters are known, for example, containing a metal body, a reaction chamber including metal grids or grids coated with a platinum-rhodium alloy, which purify gases from nitrogen oxides, hydrocarbons and carbon monoxide. The disadvantages of such converters are: the inability to use them to neutralize diesel exhaust gases, due to the fact that reaction chambers with a catalyst are clogged with soot, coke, insoluble organic substances, the creation of increased backpressures to the exhaust, leading to a decrease in diesel power.

Multistage catalysts with catalytic elements are also known, comprising an air supply between the catalytic elements. The disadvantages of such converters are as follows: since diesel exhaust contains up to 18% oxygen by volume, the air supply creates conditions that hinder the reduction reactions, the catalytic elements are clogged with soot.

In addition to the above, neutralizers are known that contain a catalytic reactor (reaction chamber) with inlet and outlet gratings and a perforated pipe with holes for the distribution of ammonia, in which the holes of the inlet grid along the axes coincide with the holes in the perforated pipe 3. The design of such a catalyst is closest in technical essence and is a prototype. The disadvantages of such a catalyst are the following: the catalyst is not multistage and does not carry out sequentially oxidative and reduction reactions, through the lattices at partitions, the removal of worn catalyst elements on the support is observed.

The purpose of the invention is to increase the efficiency of exhaust gas purification of internal combustion engines by activating reduction and oxidation reactions in catalytic reaction zones.

This goal is achieved in that in a known converter comprising a double-walled housing, thermal insulation, a reaction chamber with a fluidized bed of catalyst, inlet and outlet lattices, a top cover with a plug, an inlet and outlet pipe, an ammonia distributor in the form of a hollow pipe, according to According to the invention, the reaction chamber is provided with an outlet grill in the form of a porous metal-ceramic catalytic block, in which a pipe is introduced to supply gas, for example, ammonia to the reaction zone.

The drawing shows the neutralizer along the axis, a longitudinal section.

The converter contains a housing, which consists of an upper part 1 and a lower part 2. A reaction chamber 3 is located in the housing, and heat insulation 4 is placed between the walls of the converter housing and the reaction chamber 3. An inlet pipe 5 with a flange 6 is cut into the lower part of the housing, and an outlet pipe 7 with a flange 8 is embedded in the upper part 1 of the housing. A perforated pipe 9 with holes 10 is fixed to the upper part 1 of the housing, closed by a cap 11. A fitting 12 is connected to the cap 11 to which the tube is connected

13 gas supply. The inlet pipe 5 is designed to supply exhaust gas 14, in the exhaust pipe 7 is designed to exhaust the purified gases 15. Inlet bottom 16 is made in the lower part of the reaction chamber 3, and bulk catalyst 17 is placed in the reaction chamber. The outlet lattice in the reaction chamber 3 is made in the form porous cermet block 18 and secured with a collar 19 in the upper part 1 of the body, a ring 20 located between the collar 19 and the reaction chamber 3 and the collar 21 in the reaction chamber 3. The reaction chamber 3 is fixed in the collar housing 19 in the upper part and a collar 22 in the lower part 2. The floor of the perforated pipe 9 is installed vertically in the housing and inserted into the porous metal-ceramic block 18 and the holes 10 on its lateral surface are blocked by the porous material of the block 18, and on the end wall of the pipe 9 in zone of the reaction chamber made an additional hole 23.

The operation of the spent catalyst

gases is carried out as follows.

In the process, exhaust gases

14 from the engine through the inlet pipe 6 to the grate 16 and enter the reaction chamber 3 with a fluidized bed of catalyst 17, where the oxidation of carbon monoxide to carbon dioxide and hydrocarbons, grinding in the fluidized bed of soot particles and their afterburning take place. In the after-oxidation zone of products of incomplete combustion, through holes 23

the nozzle 12 and pipe 9 are gas, for example ammonia, which serves to bind free oxygen. Exhaust gases with additionally oxidized products of incomplete combustion and soot enter the porous metal-ceramic-catalytic block 18 into the reduction zone of nitrogen oxides in it through additional openings 10 in the pipe 9, additional gas, for example, ammonia, which provides good conditions for the course of the reduction reactions. This embodiment of the catalyst provides favorable conditions not only for the oxidation of products of incomplete combustion, but also for the reduction of nitrogen oxides. Thus, the design improves the efficiency of diesel exhaust gas cleaning. The installation of a porous metal-ceramic catalytic block prevents the removal of a worn catalyst from the catalyst. The purification efficiency of nitrogen oxides is increased to 75%.

Compared to the prototype, the exhaust gas neutralizer provides: a more complete reduction of nitrogen oxides; reduction of carbon monoxide, hydrocarbon and soot emissions, prevention of catalyst removal. The effect of reducing exhaust emissions is achieved for the following reasons. The gas supply to the oxidation zone of products of incomplete combustion creates conditions

to reduce the free oxygen content in the exhaust stream, which subsequently creates conditions for the reduction of nitrogen oxides. The gas supply to the reduction zone of nitrogen oxides contributes to the creation of a non-oxidizing medium in the reaction zone.

Claims (1)

The economic effect of using one converter with a 4h13 / 14 engine with a power of 440 kW at 1700 is 0.7 thousand rubles per year. SUMMARY OF THE INVENTION An exhaust gas neutralizer, a housing with an inlet and an outlet rc gratings, a reaction chamber with a fluidized bed of catalyst located between the gratings, an inlet and an outlet nozzle mounted on the casing, and an ammonia distributor located in the zone of the reaction chamber and made in the form of a hollow pipe with holes on its lateral surface and an end wall, characterized in that, in order to increase the cleaning efficiency by activating reduction and oxidation reactions, the outlet grate and it is made in the form of a porous cermet block, the ammonia distributor is installed in the latter vertically with the possibility of placing holes in the cermet block, and its end wall in the reaction chamber, the end wall being made with an additional hole.