Michael E Cloud

US Patent:

7588634, Sep 15, 2009

Filed:

Sep 20, 2006

Appl. No.:

11/533604

Inventors:

Michael R. Lynn - Arlington Heights IL, US
W. David Song - Gurnee IL, US
Qingxia Liu - Vernon Hills IL, US
Qiang Yu - Grayslake IL, US
Michael L. Cloud - Canton OK, US

Assignee:

United States Gypsum Company - Chicago IL

International Classification:

C04B 11/00

US Classification:

106772, 423555

Abstract:

A process is disclosed for making a blend of alpha- and beta-stucco including a slurry calcination step to produce alpha calcium sulfate hemihydrate followed by a fluidized bed calcination step to produce beta calcium sulfate hemihydrate. The process starts with 50-75% gypsum-containing solids slurry, and then steam calcines the slurry in a first reactor to form partially calcined gypsum slurry which contains calcium sulfate dihydrate and alpha calcium sulfate hemihydrate. The partially calcined slurry is then dewatered. Then the filter cake is fed into a kettle to complete the calcination process by converting the calcium sulfate dihydrate of the filter cake material into beta calcium sulfate hemihydrate.

US Patent:

57439540, Apr 28, 1998

Filed:

Feb 2, 1995

Appl. No.:

8/382612

Inventors:

George E. Rowland - Naperville IL
Michael L. Cloud - Canton OK
Daniel J. Milligan - Watonga OK

Assignee:

United States Gypsum Company - Chicago IL

International Classification:

C04B 1100

US Classification:

106783

Abstract:

A method and apparatus is disclosed for the continuous calcining of gypsum material in a high-efficiency, refractoryless kettle preferably heated by a multiple series of separate immersion tube burner coils, each coil operating within a specific calcining zone inside the kettle. The lowest, i. e. , initial, burner tube coil is formed with a low profile to permit use of a small initial gypsum charge, and hence, a quick kettle start-up cycle. That low profile initial burner design also helps keep the agitator motor's load at a minimum during cycle start-up. Due to the immersion tube burner coil construction, no refractory structure for the kettle is required. Also, no separate hot pit structure is required, as the kettle is used to merely hold the material being calcined and no residual heat is present. A relatively thin kettle can be constructed, as it need only withstand relatively low operating temperatures. The kettle's staged, interiorly-disposed burner tube coils act to directly transfer burner tube heat to the kettle's contents, and the coils exhaust exteriorly of the kettle.

US Patent:

59279680, Jul 27, 1999

Filed:

Dec 23, 1997

Appl. No.:

8/997205

Inventors:

George E. Rowland - Naperville IL
Michael L. Cloud - Canton OK
Daniel J. Milligan - Watonga OK

Assignee:

United States Gypsum Company - Chicago IL

International Classification:

F27B 514

US Classification:

432102

Abstract:

A method and apparatus is disclosed for the continuous calcining of gypsum material in a high-efficiency, refractoryless kettle preferably heated by a multiple series of separate immersion tube burner coils, each coil operating within a specific calcining zone inside the kettle. The lowest, i. e. , initial, burner tube coil is formed with a low profile to permit use of a small initial gypsum charge, and hence, a quick kettle start-up cycle. That low profile initial burner design also helps keep the agitator motor's load at a minimum during cycle start-up. Due to the immersion tube burner coil construction, no refractory structure for the kettle is required. Also, no separate hot pit structure is required, as the kettle is used to merely hold the material being calcined and no residual heat is present. A relatively thin kettle can be constructed, as it need only withstand relatively low operating temperatures. The kettle's staged, interiorly-disposed burner tube coils act to directly transfer burner tube heat to the kettle's contents, and the coils exhaust exteriorly of the kettle.