Electric treating method for exhaust gas of diesel engine and its device

Abstract

To provide an exhaust gas treating technology of diesel engines capable of removing PM in exhaust gas of diesel engines with high efficiency and capable of exhibiting stabilized performance over a long term. [MEANS FOR SOLVING PROBLEMS] A discharging / charging section comprising a corona discharging section and a charging section is disposed on the upstream side of an exhaust gas passage in order to charge granular substances principally comprising carbon with corona discharged electrons, and then the charged granular substances are collected at a collecting section arranged on the exhaust gaspassage.

Description

technical field [0001] The present invention relates to an exhaust gas treatment technology for removing and purifying particulate matter (Particulate Matter: hereinafter referred to as "PM") mainly containing carbon contained in the exhaust gas of a diesel engine. Discharged Diesel Engine Exhaust Gases Using Electric Treatment Technology. Background technique [0002] As we all know, the PM contained in the exhaust gas of a diesel engine not only causes air pollution, but also is a very harmful substance to the human body. Therefore, it is very important to purify the exhaust gas. Therefore, improvements in the combustion method of diesel engines, adoption of various filters, or methods of electrical treatment using corona discharge have been proposed. [0003] However, since diesel engines perform various operations such as cold start, hill climbing, and overloading, it is difficult to significantly reduce PM only by improving the combustion method. In addition, for exam...

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Problems solved by technology

[0009] The exhaust gas PM collection devices described in Patent Documents 1 and 2 use a so-called one-stage type electric dust collector system. The basic problem is that the discharge voltage and the collection deflection voltage are at the same potential, so It is difficult to set the two voltages to appropriate conditions, and in order to prevent sparks between the deflection electrode and the collection electrode, it is necessary to increase the distance between them. Therefore, the exhaust gas PM collection devices described in Patent Documents 1 and 2 have There are many particles that are not trapped and pass through the trapping area, and the trapping efficiency is low. In addition, in order to improve the trapping efficiency, the capacity of the trapping part must be increased, which will inevitably lead to a large-scale device, which is not suitable for It is used as an automobile part that is expected to be small and lightweight. Furthermore, the exhaust gas purification device described in Patent Document 3 adopts a so-called two-stage type electric dust collector, and since no pollution countermeasures with needle electrodes Therefore, when a high voltage of tens of thousands of volts is applied to the discharge electrode, the electrical insulation will be reduced due to pollution, and the PM capture performance cannot be exerted. Moreover, the discharge electrode cannot avoid the pollution of corrosive exhaust gas. damage, long-term use cannot maintain stable performance. Furthermore, in the case of linear electrodes, the vibration or impact of the car during driving is likely to cause disconnection, and there are also problems in terms of strength. That is, the existing corona discharge In the exhaust gas treatment mechanism of electrical treatment, it is difficult to ensure high insulation of the discharge electrode, and there are difficulties in practicality.

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