David Hopkins

US Patent:

6436213, Aug 20, 2002

Filed:

Aug 24, 2000

Appl. No.:

09/645182

Inventors:

David H. Hopkins - Escondido CA

Assignee:

PTI Advanced Filtration, Inc. - Oxnard CA

International Classification:

B32B 3116

US Classification:

156 731, 156269, 1563082

Abstract:

Embodiments of the present invention relate to a membrane assembly useful in an electro-deposition coating system and a method for constructing such a membrane assembly. The membrane assembly may include a membrane sheet, a guide and a frame. In an embodiment of the invention, the membrane assembly may be formed in a tubular shape by ultrasonically welding a membrane sheet along a spiral seam and placing the membrane sheet between a guide and frame formed form extruded net tubing. Alternative embodiments of the invention may incorporate different seam shapes and manufacturing and joining methods.

US Patent:

48427365, Jun 27, 1989

Filed:

Sep 6, 1988

Appl. No.:

7/240941

Inventors:

Donald T. Bray - Escondido CA
David H. Hopkins - Escondido CA

Assignee:

Desalination Systems, Inc. - Escondido CA

International Classification:

B01D 1300

US Classification:

21032161

Abstract:

A spiral wound membrane cartridge for use in separating a first component from a feed fluid mixture of the first component and the second component. The cartridge includes a permeate collection tube and at least one permeate carrier leaf extending outwardly from the tube. The cartridge further includes at least one sandwich leaf extending outwardly from the tube and including a length of a semipermeable membrane sheet which has an active membrane side and a backing side. This sheet is folded in two, having the fold positioned adjacent the tube and with the membrane sides of the two parts of the folded sheet facing. The sandwich leaf also includes a length of a feed carrier positioned between the two parts of the folded membrane sheet. The sandwich leaf includes a flexible sealer which penetrates and seals the interstices of the backing side in the area of the fold so that, in the event of damage to the membrane side adjacent the fold, the sealer prevents leakage of the feed fluid mixture to the permeate collection tube. Methods of making the sandwich leaf are also disclosed.

US Patent:

52385639, Aug 24, 1993

Filed:

Jul 29, 1992

Appl. No.:

7/921875

Inventors:

Dean L. Smith - Mountainside NJ
Charles P. Darnell - Baton Rouge LA
Tan-Jen Chen - Baton Rouge LA
Richard J. Basile - Wharton NJ
Burghard H. Ruterbories - Morris Plains NJ
David H. Hopkins - Escondido CA

Assignee:

Exxon Research & Engineering Company - Florham Park NJ

International Classification:

B01D 6312

US Classification:

21032174

Abstract:

A multi-element housing is disclosed for the containment of multiple membrane separation elements in parallel. The multi-element housing is characterized in that the elements are grouped in parallel with a feed/retentate zone, defined by a space enclosed by two tube sheets arranged at the same end of the elements. The central mandrels of the elements pass through the feed/retentate zone space defined by the two tube sheets and empty permeate outside the defined space into a permeate collection zone from which it is removed, while the tube sheet directly attached to the element is in open relationship to the interior of the membrane element and retentate accumulates in the space between the top tube sheet and the bottom tube sheet from which it is removed.

US Patent:

52661954, Nov 30, 1993

Filed:

Aug 10, 1992

Appl. No.:

7/927340

Inventors:

David H. Hopkins - Escondido CA

Assignee:

Desalination Systems, Inc. - Escondido CA

International Classification:

B01D 6310

US Classification:

21032174

Abstract:

A sandwich of a permeate fabric material within a folded sheet of semipermeable membrane is spirally wound together with a sheet of porous feed pathway material about a mandrel which, upon its removal, provides a central hollow region in the wound element. A single band of adhesive seals the outer end of the envelope, and once wrapping is completed, a thin layer of porous tape holds the winding tight. A porous small diameter tube is inserted into a pocket adjacent the fold in the semipermeable membrane material near the center of the winding and serves as a permeate discharge conduit. Axial ends of the spirally wound subassembly are sequentially potted in resin to complete the basic fabrication of the element. Communication with the feed pathway material is provided by drilling through the resin into the center hollow region. The spirally wound element can be used as a replacement cartridge for a device having a permanent housing, or it can be integrally bonded within a surrounding pressure vessel assembly to form a disposable water purification unit.

US Patent:

D2958872, May 24, 1988

Filed:

Jan 30, 1986

Appl. No.:

6/824134

Inventors:

David H. Hopkins - Escondido CA

Assignee:

Nimbus Water Systems, Inc. - Escondido CA

US Classification:

D23207

US Patent:

49063723, Mar 6, 1990

Filed:

May 17, 1989

Appl. No.:

7/352999

Inventors:

David H. Hopkins - Escondido CA

Assignee:

Desalination Systems, Inc. - Escondido CA

International Classification:

B01D 1300
B01D 2700

US Classification:

21032174

Abstract:

A reverse osmosis or ultrafiltration separation device for treating a liquid feed wherein a separation assembly is wound spirally about a central permeate-carrying tube. The assembly includes an elongated semipermeable membrane envelope which includes an interior permeate passageway and feed-passageway-providing sheet material spirally wound with said envelope to supply a liquid feed to be treated. A cylindrical housing of circular cross section having an inlet and a pair of outlets holds the spiral wound separation assembly which is tightly surrounded by a seamless, highly porous, rigid, tubular sleeve proportioned to be snugly received within the cylindrical housing. The sleeve has a predetermined thickness relative to the diameter of the housing chamber so that a desired amount of bypass flow of liquid occurs through the space generally occupied by the sleeve.