Pravin S Murkute

US Patent:

20040139992, Jul 22, 2004

Filed:

Dec 18, 2003

Appl. No.:

10/740657

Inventors:

Pravin Murkute - Carlsbad CA, US
P. Tvaruzek - Brno, CZ

Assignee:

Hydranautics

International Classification:

B08B007/04
B08B003/00

US Classification:

134/037000, 134/036000

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.

US Patent:

20040188339, Sep 30, 2004

Filed:

Mar 5, 2004

Appl. No.:

10/795022

Inventors:

Pravin Murkute - Carlsbad CA, US
Christopher Hermanson - San Diego CA, US
Craig Bartels - San Diego CA, US
Mark Wilf - San Diego CA, US
Graeme Pearce - Whitchurch, GB
Dirk deWinter - Vista CA, US
Marco Schilling - El Cajon CA, US

Assignee:

Hydranautics

International Classification:

B01D063/04

US Classification:

210/321800, 210/321790, 210/323200

Abstract:

A modular membrane filtration device is provided with replaceable membrane elements. The device is designed for ease of cleaning or replacing the membrane elements during filtration of a feed liquid to remove suspended solids. The cleaning may be effected by continuous aeration or by application of air as intermittent pressurized pulses. The device preferably has two headers, at least one of which is a permeate collection header having receptacles for a plurality of membrane elements, each of which is a potted hollow fiber membrane bundle. The potted hollow fiber membrane bundles are distinct entities which may be inserted into the receptacles, preferably in rows of circular slots, on the permeate collection header(s), and may be easily removed for maintenance, such as for replacement of the hollow fiber membrane elements.