David L Gregg

US Patent:

43345794, Jun 15, 1982

Filed:

Aug 29, 1980

Appl. No.:

6/182561

Inventors:

David W. Gregg - Moraga CA

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

E21B 43243
E21B 4330
E21C 4300

US Classification:

166256

Abstract:

A method of gasification of coal in deep, thin seams by using controlled bending subsidence to confine gas flow to a region close to the unconsumed coal face. The injection point is moved sequentially around the perimeter of a coal removal area from a production well to sweep out the area to cause the controlled bending subsidence. The injection holes are drilled vertically into the coal seam through the overburden or horizontally into the seam from an exposed coal face. The method is particularly applicable to deep, thin seams found in the eastern United States and at abandoned strip mines where thin seams were surface mined into a hillside or down a modest dip until the overburden became too thick for further mining.

US Patent:

53381157, Aug 16, 1994

Filed:

Dec 11, 1992

Appl. No.:

7/989305

Inventors:

David W. Gregg - Moraga CA

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

B01F 512

US Classification:

366263

Abstract:

An auger-tube pump mixing device for mixing materials with large density differences while maintaining low stirring RPM and low power consumption. The mixing device minimizes the formation of vortexes and minimizes the incorporation of small bubbles in the liquid during mixing. By avoiding the creation of a vortex the device provides efficient stirring of full containers without spillage over the edge. Also, the device solves the problem of effective mixing in vessels where the liquid height is large compared to the diameter. Because of the gentle stirring or mixing by the device, it has application for biomedical uses where cell damage is to be avoided.

US Patent:

42291844, Oct 21, 1980

Filed:

Apr 13, 1979

Appl. No.:

6/029962

Inventors:

David W. Gregg - Moraga CA

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

B01J 300

US Classification:

48 62R

Abstract:

Apparatus for using focused solar radiation to gasify coal and other carbonaceous materials. Incident solar radiation is focused from an array of heliostats onto a tower-mounted secondary mirror which redirects the focused solar radiation down through a window onto the surface of a vertically-moving bed of coal, or a fluidized bed of coal, contained within a gasification reactor. The reactor is designed to minimize contact between the window and solids in the reactor. Steam introduced into the gasification reactor reacts with the heated coal to produce gas consisting mainly of carbon monoxide and hydrogen, commonly called "synthesis gas", which can be converted to methane, methanol, gasoline, and other useful products. One of the novel features of the invention is the generation of process steam at the rear surface of the secondary mirror.