Patent ID: 6395186
Filing Date: 2002-05-28
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 bridge and thus blind 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 bridge and blind said gaps and thus substantially immediately render said filter unit substantially inoperative; fixing at least one ultrasonic transducer on said housing for 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 said carrier liquid and coalescing solids particles through said gaps and preventing said coalescing solids particles from coalescing and thus bridging and blinding said gaps while continuing said through flow at said relatively higher through flow rate.