Title: Method and apparatus for fast testing air permeability of sand casting mould
Application Number: 90106591 Application Date: 1990.07.31
Publication Number: 1049055 Publication Date: 1991.02.06
Approval Pub. Date: Granted Pub. Date: 1992.06.24
International Classifi-cation: G01N7/10,G01N15/08
Applicant(s) Name: Li Dayong Address: 156001
Inventor(s) Name:
Attorney & Agent: LI YUNXIA
Abstract:
     A pressure source with a definite volume and initial pressure discharges its air via exhaust valve and sand mould or casting mould. When the pressure of the source is reduced to a P1 value, time counting begins. After a time elapse of delta t, the pressure is reduced from P1 to P2. Under the conditions of constant geometric size and compactness of sand mould and constant initial pressure and pressure change range (P1-P2) of pressure source, the exhaust time (delta t) is only related to the air permeability of sand mould. It features simple equipment and accurate measurement.
Time: 8