Process and an apparatus for determining pressure losses of exhaust gas purification honeycomb structural bodies, by presumption, at respective points of time when honeycomb structural bodies are to be regenerated

• US 5,398,541 A
• Filed: 03/18/1993
• Issued: 03/21/1995
• Est. Priority Date: 03/23/1992
• Status: Expired due to Term

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Yamada, Satoru, Hijikata, Toshihiko
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): Brock, Michael J.
• Application Number:
  US08/033,555
• Time in Patent Office: 733 Days
• Field of Search: 55/270, 55/274, 73/38
• US Class Current: 73/38
• CPC Class Codes: B01D 46/2418 Honeycomb filters used for filtering exhaust gases of an internal combustion engine F01N3/022; ceramic honeycomb structures per se C04B38/0006
• CPC Class Codes: B01D 46/446 by pressure measuring
• CPC Class Codes: B01D 46/84 by heating only
• CPC Class Codes: F01N 2550/04 Filtering activity of particulate filters
• CPC Class Codes: F01N 3/023 using means for regenerating the filters, e.g. by burning trapped particles by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: G01M 3/26 by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors

Abstract

A process is disclosed for determining a pressure loss of exhaust gas purification honeycomb structural bodies to be inspected, at a point of time when the honeycomb structural body is to be regenerated, said honeycomb structural body having a number of through holes alternatively sealed at opposite end faces, comprising the steps of: (1) flowing particles through each of exhaust gas purification honeycomb structural bodies of a given type in an axial direction of the through holes thereof, (2) determining a relationship between the pressure loss of the exhaust gas purification honeycomb structural body at a point of time when the honeycomb structural body catches a given amount of the particles and the pressure loss of the honeycomb structural body at a point of time when the honeycomb structural body catches the particles in such an amount suitable for the regeneration, (3) then measuring the pressure loss of a honeycomb structural body to be inspected, at a point of time when the honeycomb structural body to be inspected catches said given amount of the particles, and (4) based on the thus measured pressure loss, presuming the pressure loss at a point of time suitable for the regeneration thereof with reference to the relationship determined above. An apparatus is also disclosed to effect the above process.

Claims

1. A process for determining a pressure loss of exhaust gas purification honeycomb structural bodies to be inspected, at a point in time when the honeycomb structural body is to be regenerated, said honeycomb structural body having a number of through holes alternatively sealed at opposite end faces, comprising the steps of:

(1) flowing particles through each of several test exhaust gas purification honeycomb structural bodies of a given type in an axial direction of the through holes thereof;

(2) measuring, for each Of the several test exhaust gas purification honeycomb structural bodies, (i) a pressure loss therethrough at a first point in time when the test honeycomb structural body traps a given amount of the particles and (ii) the pressure loss through the test honeycomb structural body at a second point in time when the test honeycomb structural body traps the particles in Such an amount suitable for regeneration;

(3) determining a relationship between the measured pressure losses of the several test exhaust gas purification honeycomb structural bodies at said first point in time and the measured pressure losses of the several test honeycomb structural bodies at said second point in time;

(4) measuring the pressure loss of a honeycomb structural body to be inspected, at a point in time when the honeycomb structural body to be inspected traps said given amount of the particles; and

(5) based on the thus measured pressure loss, presuming the pressure loss of said honeycomb structural body to be inspected at a point in time suitable for regeneration thereof with reference to said relationship.

2. The process of claim 1, wherein the pressure loss of said honeycomb structural body is measured at a point in time when an amount of particles trapped by the honeycomb structural body equals 1/50 to 1/2 of that at the point in time when the honeycomb structural body is to be regenerated.

3. An apparatus for determining, by presumption, pressure loss of exhaust gas purification honeycomb structural bodies having a number of through holes alternatively sealed at opposite end faces, said apparatus comprising:

a support table for gas-tightly supporting a periphery of an end portion of an exhaust gas purification honeycomb structural body having a number of through holes alternatively sealed at opposite end faces;

a particle-containing gas generator connected to said support table through a flow path and adapted for generating a particle-containing gas;

a flow path-switching valve for opening or closing said flow path relative to said honeycomb structural body by switching;

an inspection time-adjusting timer for allowing a given amount of particles to be heaped on said honeycomb structural body by opening and closing the flow path with said flow path-switching valve; and

a differential pressure gauge for measuring a pressure difference between an inlet side and an outlet side of said exhaust gas purification honeycomb structural body set on said supporting table.