RU2187000C1 - Device for cleaning exhaust gases from soot and suppressing noises of diesel engine - Google Patents

Abstract

FIELD: mechanical engineering; diesel engines. SUBSTANCE: exhaust gases get into resonance chamber and then into expansion chamber accommodating acoustic vibrations generator. Under action of sound waves suspended particles of soot contained in exhaust gases start vibrating. Number of collisions of soot particles considerably increases, and particles coagulate forming larger size soot particles. This materially facilitates subsequent cleaning of exhaust gases in electric centrifugal filter. In filter particles of soot near corona-forming electrodes absorb positive ions on their surfaces, thus acquiring positive charge. These particles, under action of electric and centrifugal forces, move to settling chamber. Under action of gravity forces and flow moving in direction of filter axis, particles of soot are trained into hopper designed for accumulating soot separated from exhaust gases. Cleaned gases are directed into exhaust branch pipe. EFFECT: improved efficiency of exhaust gas cleaning from soot. 1 dwg

Description

 The device relates to the field of engine building, in particular to exhaust systems for diesel engines.

 Known designs of devices for reducing noise and cleaning soot from exhaust gases of internal combustion engines. For example, widely used noise suppressors (see Orlin AS, Kruglov MG "Piston and combined engine systems." - M.: Mashinostroenie, 1985).

 One of the known devices for cleaning soot from exhaust gases and reducing the noise of diesel engines is the device described in the journal MTZ: Motortechn. Z, 1989 DE, 50, N 4, 170, 172. Its construction is a large number of perforated tubes that are wrapped in ceramic fibers. In a silencer housing made of steel, these tubes are mounted parallel to each other. The degree of purification from soot of diesel exhaust gas reaches 35%.

 A significant disadvantage of this device is the fast clogging of the filter element and the need for periodic regeneration. which complicates the design and maintenance of the particulate filter. In addition, the large resistance at the outlet, which filters of this type create, significantly affects the technical and economic performance of the engine.

 The closest analogue of the invention is a device for cleaning soot from exhaust gases and reducing the noise of internal combustion engines according to patent 2105164 (see bulletin 5, 1998).

 This device is an electric centrifugal filter located in the silencer housing, which has resonance and expansion chambers. The electrocentrifugal filter contains a precipitation chamber with a corona electrode located in it. In the inlet of the filter are ionizing electrodes. The device also contains an exhaust pipe, a hopper for collecting soot separated from the gas stream and a power supply. The gas stream from the resonant and expansion chambers of the muffler enters the ionizing pipe, where soot particles suspended in the exhaust gases are pre-charged. Next, the exhaust gases enter the centrifugal filter. In the zone of the corona discharge, soot particles acquire a negative charge and, under the action of electric and centrifugal forces, move to the inner surface of the precipitation electrode. Then, under the action of gravity and axially moving soot-gas flow, they enter the hopper. The cleaned exhaust gases exit the filter through the exhaust pipe.

 The disadvantage of this device is the reduced efficiency of cleaning exhaust gases from small particles of soot due to the relatively weak effect of centrifugal forces on them. Also, there is a decrease in the efficiency of electrical filtration due to a decrease in the particle drift velocity. In diesel exhaust gas, soot is contained in the form of particles of irregular shape ranging in size from tenths to hundreds of micrometers. Most soot particles are less than 0.5 microns in size. Just particles of this size are poorly trapped in an electric centrifugal filter.

 Solving the problem of cleaning the exhaust gases of a diesel engine from soot requires eliminating this drawback.

 The invention solves the problem of increasing the efficiency of cleaning soot from exhaust gases of diesel engines.

 The essence of the invention lies in the fact that a device for cleaning soot from exhaust gases and reducing the noise of a diesel engine, comprising a resonant and expansion chamber made in a muffler, an electrocentrifugal filter consisting of a precipitation chamber and a corona electrode located in it, connected to different poles of the power supply, the input pipe with ionizing electrodes, the output pipe and the hopper, according to the invention is equipped with an acoustic oscillator installed in the expansion to As the muffler. The difference is also that the horizontal axis of the acoustic oscillator coincides with the horizontal axis of symmetry of the expansion chamber, with the emitter of the acoustic oscillator facing the resonant chamber.

 The installation of an acoustic oscillation generator in the expansion chamber makes it possible to increase the degree of purification of exhaust gases from soot in an electric centrifugal filter by enlarging the particles before entering the ionizing branch pipe. Under the action of oscillations generated by the radiator, small soot particles are coagulated in the exhaust gas stream.

 The invention is illustrated in the drawing, which shows a schematic diagram of a device for cleaning soot from exhaust gases and reducing noise of diesel engines.

 The device comprises resonant 1 and expansion 2 chambers made in a silencer. An acoustic oscillation generator 3 is located in the expansion chamber 3. Ionizing electrodes 5 are located in the inlet pipe 4. Next, an electrocentrifugal filter is located in the silencer body, the casing of which is a precipitation chamber 6 with a corona electrode 7 located in it. A hopper 8 is made in the lower part of the filter to collect the separated in the process of cleaning soot from the exhaust gases, and in the upper part, the outlet pipe 9. The deposition chamber 6 and the corona electrode 7 are connected to various poles of the power supply 10.

 A device for cleaning soot from exhaust gases and reducing noise of diesel engines works as follows.

 The exhaust gases (exhaust gas) enter the silencer's resonant chamber 1, then into the expansion chamber 2. The acoustic oscillation generator 3 is located in chamber 2 (for example, an axial dynamic siren, which is driven by a compressor and a gas turbine). Under the influence of sound waves of the generator, the suspended particles of soot contained in the exhaust gases begin to oscillate. The acoustic oscillator faces the resonant chamber 2, as a result of which the number of collisions of soot particles with each other increases significantly, the particles coagulate, forming large particles that are sent to the inlet pipe 4 with the ionizing electrodes 5 located in the latter, where pre-charging in an electric field takes place particulate matter soot suspended in exhaust gases. Then the soot-gas stream, turning and spinning, enters the electric centrifugal filter. In the immediate vicinity of the corona electrode 7 (in the corona discharge zone), soot particles adsorb positive ions on their surfaces and acquire a positive charge. Under the action of electric and centrifugal forces, these particles move to the walls of the precipitation chamber 6. The corona electrode and the precipitation chamber are connected to different poles of the power supply 10. Then, due to the influence of gravity and the axially moving stream, soot particles are transferred to the hopper 8 designed to collect soot separated from the exhaust gases. The purified gases are sent to the outlet pipe 9.

 The diesel noise level is reduced by reducing the gas flow rate in the resonance and expansion chambers, as well as in the electric centrifugal filter.

 Thus, due to the described processes, the soot is removed from the exhaust gases of diesel engines and noise reduction. The efficiency of cleaning soot from exhaust gases, compared with similar devices, increases to 91%.

Claims (2)

 1. A device for cleaning soot from exhaust gases and reducing the noise of a diesel engine, containing a resonant and expansion chambers installed in the muffler, an electrocentrifugal filter consisting of a precipitation chamber and a corona electrode located in it, connected to different poles of the power supply unit, an inlet pipe with ionizing electrodes , outlet pipe and hopper, characterized in that it is equipped with an acoustic oscillator installed in the expansion chamber of the muffler.  2. The device according to claim 1, characterized in that the horizontal axis of the acoustic oscillator coincides with the horizontal axis of symmetry of the expansion chamber, the emitter of the acoustic oscillator facing the resonant chamber.