Patent ID: 6787046
Filing Date: 2004-09-07
Classification: B01D

Abstract:
A method for increasing flow rate, through a liquid pressure filter unit, of liquid-to-be-filtered having (1) a carrier liquid, (2) coalescing solids particles which tend to stick together to block a filter element gap sized substantially larger than the size of an average said coalescing solids particle, and (3) larger, impurity elements to be filtered out of said liquid-to-be-filtered and sized larger than such filter element gaps, comprising the steps:providing a liquid pressure filter unit having a housing including an inlet and an outlet and a filter element having gaps substantially larger than said particles but smaller than said larger impurity elements, said filter element having a relatively low through flow rate in which said carrier liquid and coalescing solids particles pass reliably through said gap, said filter element having a relatively higher through flow rate at which said coalescing solids particles rapidly coalesce and block flow through said gaps and thus substantially immediately render said filter unit substantially inoperative; locating at least one ultrasonic transducer in contact with liquid-to-be-filtered in said housing; admitting liquid-to-be-filtered under pressure through said filter unit inlet and into contact with said filter element while energizing said ultrasonic transducer; transmitting said ultrasonic vibrations through said liquid-to-be-filtered and thereby agitating, at an ultrasonic frequency, coalescing solids particles adjacent said gaps, thereby facilitating passage of a quantity of carrier liquid and coalescing solids particles through said gaps at said relatively higher through flow rate and preventing said coalescing solids particles from blocking flow through said gaps.