Pressure liquid filtration with ultrasonic bridging prevention

摘要

Methods and apparatus for increasing the continuous filtering flow rate through a pressure liquid filter unit of liquid-to-be-filtered having (1) a carrier liquid, (2) coalescing solids particles which tend to adhere and bridge filter clement gaps sized substantially larger than said particles and (3) larger impurity elements to be filtered out of said liquid-to-be-filtered and sized larger than such filter element gap, comprise: providing a pressure liquid filter unit having a housing with an inlet and an outlet and containing a filter element having gaps, a given gap being sized to reliably pass the carrier liquid and coalescing solids particles at a first relatively low liquid flow rate, but blocking coalescing solids particles passage therethrough due to bridging of said gaps by the coalescing solids particles at a relatively high liquid flow rate; simultaneously flowing the liquid-to-be-filtered under pressure through the inlet into the housing at the relatively high flow rate and applying ultrasonic energy to the liquid-to-be-filtered in the housing; at an ultrasonic frequency agitating the coalescing solids particles adjacent said gap and thereby passing the carrier liquid and coalescing solids particles through the gap at the relatively high flow rate without bridging and blinding of the gap by the coalescing solids particles.