The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 12, 2009
Filed:
Dec. 18, 2003
Pravin Murkute, Columbia, MD (US);
Pavel Tvaruzek, Brno, CZ;
Pravin Murkute, Columbia, MD (US);
Pavel Tvaruzek, Brno, CZ;
Hydranautics, Oceanside, CA (US);
Abstract
A method is provided for cleaning a membrane surface or maintaining a clean outside surface of a membrane during a process of outside-in membrane separation to remove suspended solids from a liquid phase. The method involves applying pressurized gas pulses to the membrane surface with individual pulse lengths of about 0.1 to 10 seconds. The pulses may be injected singularly with an interval of about 10 to 1000 seconds between pulses for a total duration of about 0.1 to 1000 hours. Alternatively, the pulses may be injected in clusters of about 2 to 100 pulses with an interval of 50-300% of the pulse length between individual pulses for a total duration of about 10 to 1000 seconds. In a preferred embodiment, both types of pulsation methods are combined in a particular sequence. The expanding gas directed toward the membrane surface in the course of one pulse dissipates energy of up to about 40 kJ/m. One embodiment of the cleaning method involves backwashing the membrane with a permeate and applying the pressurized gas pulses during the filtration and/or backwashing steps of a filtration cycle.