Robert Scott Provost

US Patent:

50546970, Oct 8, 1991

Filed:

Jan 2, 1990

Appl. No.:

7/459430

Inventors:

Robert S. Provost - Pittsburgh PA

International Classification:

B02C 1506

US Classification:

241 61

Abstract:

A coal pulverizer, that supplies a coal-in-air mixture to combustion means for a power plant and comprises grinding means consisting of wheels revolving in a power driven trough from which pulverized coal is centrifugally thrust into a stream of forced air blown upward through air passages in a throat ring consisting of uniformly sized segments, is provided with a wear ring of uniformly sized segments resting flush on the throat ring segments of equal arcuate dimension. Each said wear ring has a substantially trapezoidal cross section, the base of which rests on a throat ring segment, the vertical face of which fits against the inner wall of the pulverizer and the sloping face of which rises upward from its base at an angle measured from the vertical of between ten and seventeen degrees for approximately 21/2 and 31/2 inches, so as to deflect the coal-air stream away from direct impingement on the pulverizer housing. The provision of wear-ring segments of arcuate dimension the same as that of the underlying throat ring segments serves in novel manner to permit replacement of worn throat ring segments without the necessity of removing the grinding means from the pulverizer.

US Patent:

48741353, Oct 17, 1989

Filed:

Dec 29, 1988

Appl. No.:

7/290377

Inventors:

Robert S. Provost - Pittsburgh PA

International Classification:

B02C 1506

US Classification:

241 57

Abstract:

In the vertically oriented generally cylindrical coal pulverizers that are widely employed to supply a coal-air dispersion to the combustion zones of boilers producing steam for the turbines of electric-power plants, forced-air requirements are reduced and coal fall-back and resultant coal fires are substantially eliminated by the novel throat ring of invention. A throat ring surrounds circumferentially the coal grinding assembly of each such pulverizer and contains a plurality of angularly disposed air channels through which air is forced upwardly into contact with pulverized coal thrust centrifugally from the said assembly causing the coal-air mixture to swirl upwardly to means directing the mixture to the said combustion zones. The air channels in the throat ring of invention are in effect of reduced cross-section and comprise a convex bevel of the outer-diameter wall of each channel from the said wall to the outer rim of the throat ring thus defining the exit port of each channel of an area equivalent to the cross-section of the air-channels of the throat ring which it replaces.