Metal filtering core and production thereof

Abstract

A metallic filter core for the diesel-engine vehicle is composed of a cluster of filter core units made up of the porous thin metal band through repeated folding, pressing and welding and the long metal strips arranged the both ends of each welded seam. Each layer of said metal band has the staggered supporting slots to form the tail gas filtering channel. Its advantages are small size, high strength and high filter effect.

Description

technical field [0001] The invention relates to a metal filter element for removing black smoke particles and a manufacturing method thereof, in particular to a metal filter element for capturing soot particles of a diesel vehicle made of metal porous material and a manufacturing method thereof. Background technique [0002] Diesel vehicle exhaust contains a lot of soot particles, these particles are mainly composed of black carbonaceous substances and soluble hydrocarbons, the average particle size is small, easy to suspend in the atmosphere, easily inhaled by the human respiratory tract and deposited in the alveoli It is very harmful to human health. In order to reduce particle emissions, a filter made of a honeycomb ceramic matrix is ​​known. The exhaust gas to be purified flows into the filter channel in the filter, and the adjacent channels are closed alternately, so that the exhaust gas enters the channel from the inlet end of the filter and penetrates. Ceramic wall, ...

AI Technical Summary

Problems solved by technology

In order to reduce particle emissions, a filter made of a honeycomb ceramic matrix is ​​known. The exhaust gas to be purified flows into the filter channel in the filter, and the adjacent channels are closed alternately, so that the exhaust gas enters the channel from the inlet end of the filter and penetrates. Ceramic wall, and re-discharge at the filter outlet through adjacent channels, its main disadvantage is the anisotropy of physical parameters, the radial expansion coefficient is twice the axial expansion coefficient, so it is prone to thermal stress damage, while resisting impact , vibration performance is poor

In order to solve these problems, people have utilized the good toughness and impact resistance of metal filter materials to produce metal filter elements. Traditional metal filters have been disclosed in Japanese Patent Publication No.Hei9-245938, No.Hei11-257048 and 2002-27915. Based on the design concept of an open filter system, it is made of a metal porous body with a wavy or convex-concave shape along the vortex direction, and many through holes are formed on the wavy or convex-concave peaks or valleys. Each of the through holes has a burr-like or yoke-like protrusion formed in an edge portion thereof, which is positioned within the opposing surfaces of the metal porous bodies in a state where the metal porous bodies are joined to each other and forming an exhaust gas passage in which unburned soot particles in the exhaust gas entering a turbulent state are captured by the peak or valley surface of the metal porous body and further captured by the burr-shaped or yoke-shaped protrusions used as obstacles, However, due to the small cross-sectional area of ​​the passage and the ratio of the area in contact with the black smoke area to the cross-sectional area of ​​the passage cannot be increased, a lot of black smoke is ejected together with the exhaust gas, but is not captured by the metal filter, and cannot be removed as expected Efficiency of soot particles

Japanese Patent Publication 200410045256.2 is improved on the basis of the above, by increasing the barrier distribution rate and changing the direction of the edge of the through-hole in the corrugated or concave-shaped metal porous body in order to obtain a higher passage cross-sectional area in a limited space, so that the metal The filter can enhance the capture efficiency, but it still cannot completely remove the soot, especially for diesel vehicles that use high-sulfur diesel and have a large original soot emission, the capture efficiency is still not ideal

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