Richard A Griffith

US Patent:

60595604, May 9, 2000

Filed:

Mar 3, 1998

Appl. No.:

9/034613

Inventors:

George A. Richards - Morgantown WV
Michael C. Janus - Baltimore MD
Richard A. Griffith - Morgantown WV

Assignee:

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

International Classification:

F23C 1104
F23D 100

US Classification:

431 1

Abstract:

The periodic equivalence ratio modulation (PERM) method and apparatus significantly reduces and/or eliminates unstable conditions within a combustion chamber. The method involves modulating the equivalence ratio for the combustion device, such that the combustion device periodically operates outside of an identified unstable oscillation region. The equivalence ratio is modulated between preselected reference points, according to the shape of the oscillation region and operating parameters of the system. Preferably, the equivalence ratio is modulated from a first stable condition to a second stable condition, and, alternatively, the equivalence ratio is modulated from a stable condition to an unstable condition. The method is further applicable to multi-nozzle combustor designs, whereby individual nozzles are alternately modulated from stable to unstable conditions. Periodic equivalence ratio modulation (PERM) is accomplished by active control involving periodic, low frequency fuel modulation, whereby low frequency fuel pulses are injected into the main fuel delivery.

US Patent:

45247960, Jun 25, 1985

Filed:

Sep 24, 1982

Appl. No.:

6/422795

Inventors:

William J. Ayers - Morgantown WV
Charles R. Carter - Fairmont WV
Richard A. Griffith - Morgantown WV
Richard B. Loomis - Bruceton Mills WV
John E. Notestein - Morgantown WV

Assignee:

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

International Classification:

F16K 336
F16K 2500

US Classification:

137240

Abstract:

The invention is a flow and pressure-sealing valve for use with abrasive solids. The valve embodies special features which provide for long, reliable operating lifetimes in solids-handling service. The valve includes upper and lower transversely slidable gates, contained in separate chambers. The upper gate provides a solids-flow control function, whereas the lower gate provides a pressure-sealing function. The lower gate is supported by means for (a) lifting that gate into sealing engagement with its seat when the gate is in its open and closed positions and (b) lowering the gate out of contact with its seat to permit abrasion-free transit of the gate between its open and closed positions. When closed, the upper gate isolates the lower gate from the solids. Because of this shielding action, the sealing surface of the lower gate is not exposed to solids during transit or when it is being lifted or lowered.