SU1737140A1 - Method of purifying exhaust gases of internal combustion engine and catalytic neutralizer - Google Patents

Abstract

The invention makes it possible to increase efficiency, durability, and reduce the size and entrainment of granular catalyst from a ring-type neutralizer reactor by reducing the exhaust gas velocity through the upper surface of the walls. To implement the method, the annular reactor 4 of the neutralizer, filled with catalyst 5, with inner 6 and outer 7 perforated cylindrical walls, has an inlet cavity 9, which at least one longitudinal horizontal plate is divided into two unequal sections with decreasing volume of sections, towards the upper wall surfaces 6, 7. 5 Cp f-crystals, 8 ill. J (L

Description

gh -ll -v

-V

but

The invention relates to mechanical engineering, in particular to exhaust gas emission reduction systems of internal combustion engines.

A known method for cleaning exhaust gases of an internal combustion engine is by passing exhaust gases through a bed of granular catalyst to a reactor with internal and external perforated cylindrical walls.

The disadvantage of this method is the high ablation of the catalyst granules due to their abrasion and generation.

Known catalytic converter that implements the cleaning method and containing a ring reactor with internal and external perforated cylindrical walls, the gap between which is filled with a granular catalyst.

The disadvantages of the catalytic converter are the uneven loading of the reactor and the increased entrainment of the catalyst.

The purpose of the invention is to increase efficiency and durability.

This is achieved by supplying gases through an internal perforated wall with a variable circumferential speed, reducing it when gases pass through the upper surface of the walls, and in the catalytic converter for implementing the method, the internal cylindrical cavity is divided by at least one longitudinal partition into different volumes of sections by reducing the volume of the sections in the direction of the upper surface of the walls, the sections are made in the form of sectors in cross section with at least one common center located in the upper semicircle and the formed intersection of the longitudinal partitions, the longitudinal partition is designed as a horizontal plane, the longitudinal partition is inclined to the longitudinal axis of the reactor with the formation of a diffuser in the upper section and a confuser in the lower section, the longitudinal partitions are made with a length not exceeding half the reactor length, and output sections from the sections are provided with throttles.

Figure 1 presents the scheme of the catalytic converter with a ring-type reactor; 2 is a section A-A in FIG. 1 (with a plot of the velocity of gases through the inner wall); FIG. 3 shows a reactor divided by longitudinal partitions into sectors with a plot of gas velocities; FIG. 4 shows a reactor with a longitudinal partition in cross section and a plot of gas velocities; figure 5 - reactor, divided into

two sections of the horizontal plane; figure 6 is a diagram of the catalytic Converter with a flat partition inclined to the longitudinal axis; Fig. 7 is a diagram of the catalytic converter with a partition in the first half of the reactor length with throttles at the outlet of the flow from the sections; FIG. 8 is a section BB in FIG. 7,

The catalytic converter that implements the cleaning method includes a housing 1 with inlet 2 and outlet 3 nozzles, a reactor 4 filled with granular catalyst 5. The volume of the latter is limited by the inner and outer perforated cylindrical walls 6 and 7 and the end walls of the housing on one side and the blank wall 8 reactor on the other. The inlet cavity of the reactor 9 — the cylindrical volume of the inner wall 6 — communicates with the inlet pipe 2.

The optimum in terms of reducing abrasion, generation and entrainment of catalyst granules 5 from the working volume of the reactor with sufficiently full use of it is the plot of the velocity of gases around the circumference through the perforation of the inner wall, shown in Fig.2. The maximum speed is at the lower guide wall, where there is a coincidence of directions.

0 velocity vectors of gases, i.e. dynamic force from the side of the flow of gases and the force of the tin of granules. As the angle between these vectors increases, the velocity of the gases decreases. This avoids intense

5 of abrasion and generation of granules in a fluidized bed or fluidized bed, the probability of occurrence of which is high due to the practical complexity and time duration of the process of dense filling of the working volume with granules.

Close to the optimal gas velocity diagram is a practical implementation according to the scheme shown in FIG. 3, when the inlet cavity 9 is divided by longitudinal walls 10-12 into different sections, in particular sectors, whose cross-sectional area increases as inner wall. Division into sectors

0 of various cross-sectional areas is possible by partitions emanating from a common center located in the upper semicircle of cavity 9. Figure 4-6 presents simplified variants of solving the problem — respectively, using a curved in cross section of the partition 13, dividing cavity 9 into two sections arranged by longitudinal and unequal in volume layers 14 and 15 and with the help of a horizontal flat plate 16. In both

In some cases, the upper sections are smaller in volume than the lower ones, and these volumes fall on approximately the same perforated surfaces of the wall 6, which is especially noticeable in Fig. 4. To increase the efficiency of using a flat partition 16 (Fig. 5), the latter can be slightly inclined to the longitudinal axis of the reactor, creating a diffuser in the upper section 17 and a confusor 18 in the lower section. The latter contributes to the equalization of the differential static pressure and gas velocity from the lower part of the inner wall.

FIG. 7 and 8, a variant of the design is shown with one horizontal transom 19, no longer than half the length of the reactor, i.e. the separating part of the inlet cavity is divided into two unequal in volume sections 20 and 21. The output section of the sections is partially blocked by droplets 22 and 23, which partially equalize the differential static pressure and gas velocity along the length of the reactor. At the exit from the sections, the linear flow rate of gases is lower, and a part of the gas flow rate — significantly greater than the smooth inner wall of the reactor (Fig. 1) —was passed through the part of the inner wall that communicates with the sections. At the same time, in the rest of the cavity 9 there is a more uniform field of the static pressure drop, the gas velocities through the perforations on the wall surface, which should not be less than the velocities through the lower surface of the inner wall in section 21

The catalytic converter that implements the method of cleaning gases, works as follows.

The exhaust gases through the inlet pipe enter the inlet cavity of the reactor 9 and pass through the perforation of the inner wall 6 through an annular layer of granular catalyst in which they are cleaned from products of incomplete combustion of fuel. Through the perforation of the outer cylindrical wall 7, the gases enter the neutralizer body and are discharged through it through the outlet 3.

Claims (6)

Invention Formula 1 The method for purifying exhaust gases of an internal combustion engine by passing exhaust gases through a layer of granulated catalyst in a reactor with internal and external perforated cylindrical walls, characterized in that, in order to increase efficiency and durability, the exhaust gases are fed into the reactor through an internal perforated wall with variable circumferentially, reducing it when gases pass through the upper surface of the walls. A catalytic converter comprising an annular reactor with internal and external perforated cylindrical walls, the gap between which is filled with a granular catalyst, characterized in that, in order to increase efficiency and durability, the cavity of the internal cylindrical wall is divided by at least one longitudinal partition into sections of different size a decrease in the volume of the sections towards the upper surface of the walls, 3 The neutralizer of claim 2, wherein. that sections are made in the form of sectors in cross section with at least one center located in the upper semicircle and formed by the intersection of the longitudinal partitions. 4. The neutralizer according to claim 1, in accordance with the fact that the longitudinal partition is made in the form of a horizontal plane. A neutralizer according to claim 2, characterized in that the longitudinal partition is inclined to the longitudinal axis of the reactor to form a diffuser in the upper section and a confuser in the lower section. 6. The neutralizer of claim 2-4, wherein the hem is that the longitudinal partitions are made not longer than half the length of the reactor, and the output sections from the sections are provided with throttles. z gpf about chg CO J J O # // / 6 7 Fig.Z 6 south H 5 tf / 3 7 /five F giI s in