RU2258815C2 - Diesel engine exhaust gases two-stage soot filter - Google Patents

Abstract

FIELD: mechanical engineering; diesel engines.

SUBSTANCE: invention can be used for cleaning exhaust gases of diesel engines. Proposed two-stage soot filter of diesel engine exhaust system contains housing of rotation chamber with inlet and outlet branch pipes, swirler, soot collector with afterburner and additional filtering element. Housing of rotation chamber is made double-walled, with head isolator placed in space between walls. Soot collector with afterburner is enclosed in cup installed for longitudinal displacement along guides inside cylinder. Control return mechanism is installed in cylinders after soot collector. Return mechanism consists of spring and rod, and additional filtering element is located in space between cylinder and filter housing and is furnished with electric heater.

EFFECT: provision of effective cleaning of exhaust gases from participles of soot, reduced fuel consumption and power losses at different modes of operation of diesel engine, increased service life of filter and its overhaul life.

4 dwg

Description

The invention relates to mechanical engineering and can be used for purification of exhaust gases (exhaust) in exhaust systems of diesel engines.

A device for cleaning a diesel exhaust gas from solid particles (RF patent No. 2183751, IPC F 01 N 3/022 of 06/20/02), comprising a rotary combustion chamber with inlet and outlet pipes, a swirler, a carbon black with an afterburner, an additional filter element, the housing The rotation chamber has double walls, in the cavity between which a layer of heat insulator is embedded.

The disadvantages of this device are the increase in fuel consumption during operation, caused by an increase in exhaust backpressure at medium and full diesel load conditions due to the rapid coking of the particulate filter channels, as well as the increased complexity of the process of cleaning particulate matter from solid particles.

The technical result is aimed at providing a more efficient purification of exhaust gas from soot particles, reducing fuel consumption and power losses at various diesel engine operation modes, increasing the filter service life and its life before next service.

The technical result is achieved by the fact that the two-stage diesel particulate filter of diesel exhaust containing a rotary chamber housing with inlet and outlet nozzles, a swirler, a soot collector with an afterburner and an additional filter element, the rotary chamber housing having double walls, a layer of heat insulator is embedded in the cavity between them, wherein the carbon black with the afterburner is enclosed in a glass having the possibility of longitudinal movement inside the cylinder along the guides, behind the carbon black with the afterburner he device inside the cylinder is located control return mechanism, consisting of a spring and a rod, and an additional filter element is located in the cavity between the cylinder and the filter housing and is equipped with an electric heater.

Distinctive features of the prototype is that the soot collector with an afterburner is enclosed in a glass having the possibility of longitudinal movement inside the cylinder along the guides, behind the soot collector with an afterburner inside the cylinder there is a control return mechanism consisting of a spring and a rod, and an additional filter element is located in the cavity between the cylinder and the filter housing and is equipped with an electric heater.

The technical solution is illustrated by drawings, where Fig. 1 shows a longitudinal section of a two-stage particulate filter and its operation when the first cleaning stage is turned on; figure 2 is a longitudinal section and the filter when two stages of cleaning; figure 3 and 4 are transverse sections aa and bb.

The particulate filter consists of a housing of the rotary chamber 1 with an inlet pipe 17 and a diffuser 18, as well as an outlet pipe 19 and a confuser 20, inside of which a swirl 2 made in the form of an impeller is located in its cylindrical part. In the rotary chamber 1 there is a carbon black 3 made of alloy steel and a "tangle" of thin metal wire, with a catalytic afterburning device placed inside it 4. The catalytic afterburning device 4 is a metal cylinder 5, inside of which there are through longitudinal channels 6. On the surface of channels 6, a catalytic ceramic layer based on gamma-alumina with the addition of oxides of Cu, Cr, Ni, Co and rare earth oxides is applied. Between the swirler 2 and the carbon black 3 there is a cylindrical separating cavity 7. The carbon black 3 with a catalytic afterburning device 4 is enclosed in a cylindrical glass 15 (Fig. 4), which can be longitudinally moved inside the cylinder 8 along four guides made on its inner surface 23. For moving along guides 23, the glass 15 of the carbon black 3 has four longitudinal grooves, respectively. Behind the carbon black 3 with a catalytic afterburning device 4, inside the cylinder 8, there is a control return mechanism consisting of a spring 10, a thrust metal plate 9 with an opening for the guide rod 11 (Figs. 1, 3). In the cavity between the cylinder 8 and the filter housing 1, a fixed additional filter element 12 is coaxially located, which is fixed in the cavity 13 by the thrust plates 14 (Figs. 1, 4). An additional filter element 12 is made of ceramic "tangle", in which an electric heater 22 is placed, in the form of a nichrome (electric) spiral operating from the vehicle’s electrical network. The inclusion of an electric heater 22 is provided by the control unit 24 at the signal of the pressure sensor 21. In addition, the housing of the rotary chamber 1 has double walls with a layer of heat insulator 16 made of mineral wool (ceramic fibers).

The filter works as follows. The exhaust gases, including solid particles, enter the rotary chamber 1 through the inlet pipe 17 and, passing through the impeller 2, are twisted. In the cylindrical separation cavity 7, the solid particles are separated by mass. Heavier (larger) particles enter the peripheral region of the cavity 7, and then are captured by the carbon black 3. Smaller particles enter the catalytic afterburning device 4 located in the axial part of the rotary chamber 1. There they pass through the through longitudinal channels 6 and are in contact with the catalytic ceramic layer. When this happens, the oxidation of soot particles to carbon monoxide, which is ensured on the one hand by the chemical and phase composition of the catalytic layer, and on the other hand by the length of the channels 6. The gases purified from the solid particles exit through the outlet pipe 19 (Fig. 1).

When the engine is operating under medium load conditions, that is, when the exhaust gas flow increases, their pressure in the cavity 7 increases and begins to overcome the force of the spring 10 of the control return mechanism, while the glass 15 of the carbon black 3 moves inside the cylinder 8, giving access to an additional filtering element 12. In this case, the exhaust gases are divided into two parallel flows, one part of which is cleaned in a movable carbon black 3 with a catalytic afterburning device 4, and the other part of the gases, where larger soot particles prevail s swirler 2 enters the cavity 13, and then, purifying the additional filter 12, passes into the outlet 19 (Figure 2).

When the engine is operating at full load, the gas flow increases, the pressure in the cavity 7 increases, and the glass 15 of the carbon black 3 moves even more, increasing access to the additional filter 12.

When the exhaust gas pressure in the cavity 7 is exceeded, to a critical value characterizing the degree of clogging of the filter elements, the sensor 21 is activated and the control unit 24 includes an electric heating element 22, which provides heating of the additional filter 12 to a temperature of 550-600 ° C, which is necessary for soot burning, which contributes to the partial regeneration of an additional filter 12, as well as a carbon black 3 with a catalytic afterburning device. The presence of double walls in a rotational combustion chamber can significantly reduce heat loss to the environment.

Thus, this design of a two-stage diesel particulate filter allows to increase the area of its cross-section with increased exhaust gas flow and pressure at medium and full engine loads, which allows to minimize the total hydraulic resistance of the filter and to perform high-quality cleaning of exhaust gas in all diesel operation modes with minimal power and consumption losses fuel, and also helps to extend the life of the filter and reduce the complexity of maintenance.

Claims (1)

A two-stage diesel exhaust particulate filter containing a rotary chamber housing with inlet and outlet nozzles, a swirler, a soot collector with an afterburner, and an additional filter element, the rotary chamber housing having double walls with a heat insulator layer embedded in the cavity, characterized in that the carbon collector has the afterburning device is enclosed in a glass having the possibility of longitudinal movement inside the cylinder along the guides, behind the carbon black with the afterburning device inside the cylinder Located return control mechanism consisting of a spring and a rod, and the additional filter element is disposed in the cavity between the cylinder and the filter housing and is provided with an electric heater.

Images