Ultrasonically cleaned membrane filtration system

A filtration circuit for a liquid to be filtered comprising:

• a feed solution source,
• a pump adapted to pump;
• the feed solution source and provide the liquid to be filtered under pressure, and
• a membrane filtration system to receive the liquid to be filtered under pressure, said membrane filtration system including:
• a casing having flanges which support and sealingly close ends of the casing,
• an inlet conduit for the liquid to be filtered into the filtration system,
• an outlet conduit for removing liquid concentrate from the membrane filtration system,
• an evacuation conduit for the egress of filtered fluid, and
• a membrane cell having a filtration membrane which filters the liquid to be filtered and permeates the filtered fluid to the evacuation conduit, and an ultrasonic transducer in direct contact with the liquid to be filtered and adapted to direct ultrasonic energy at said filtration membrane, wherein said ultrasonic transducer has a ring shape and said filtration membrane has a cylindrical shape, and said ultrasonic transducer surrounds said filtration membrane, or is surrounded by said filtration membrane, and further comprising means for guiding movement of the transducer longitudinally along a length of the filtration membrane.

A process for ultrasonic cleaning of a filtration system having a casing having flanges which support and sealingly close ends of the casing, an inlet conduit for introducing the liquid to be filtered into the casing, an outlet conduit for removing liquid concentrate from the casing, an evacuation conduit for the egress of filtered fluid from the casing, and a membrane cell having a porous filtration membrane which filters the liquid to be filtered and permeates the filtered fluid to the evacuation conduit, and an ultrasonic transducer in direct contact with the liquid to be filtered and adapted to direct ultrasonic energy at said filtration membrane, wherein said ultrasonic transducer has a ring shape and said filtration membrane has a cylindrical shape, and said ultrasonic transducer surrounds said filtration membrane, or is surrounded by said filtration membrane, and further comprising means for guiding movement of the transducer longitudinally along a length of the filtration membrane, the process comprising:

• emitting ultrasonic energy by means of said ultrasonic transducer in direct contact with the liquid to be filtered substantially perpendicular to said filtration membrane in such a manner as to liberate particles retained by said filtration membrane;
• and
• evacuating said particles liberated from the filtration membrane via the outlet conduit of said filtration system.