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US 5,667,149 AGranted
Solids pulverizer mill and process utilizing interactive air port nozzles
AssigneeFoster Wheeler Energy Corporation
InventorFrantisek L. Eisinger
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AssigneeFoster Wheeler Energy Corporation
InventorFrantisek L. Eisinger
Estimating the term…
A solids pulverizing mill for producing fine particles such as coal dust, which includes a housing having a centrally located coal feed chute and enclosing an annular-shaped air port ring containing multiple nozzles located around a rotatable grinding table. Multiple grinding rollers press down and rotate upon the coal on the rotatable grinding table so as to pulverize the coal, which is then entrained by multiple intersecting and strongly interacting air jet streams upwardly from the grinding table through a classifier section to an exit conduit. The air port nozzle ring is fitted with multiple angled flow passages from which adjacent air jet streams intersect and interact strongly with the adjacent streams to product intense turbulence, which prevents undesirable acoustic vibration of the upflowing air/coal material within the mill housing. The centerlines of adjacent air jet nozzles intersect at an included angle of at least 20.degree. and not exceeding 90.degree., each nozzle has cross-sectional area of 10-50 in..sup.2, and provides nozzle exit air flow velocities of 140-250 ft/sec so as to prevent undesired acoustic resonance vibrations within the pulverizer mill.
A solids pulverizer mill assembly for pulverizing coarse particulate materials, the mill including a housing, a grinding table rotatably mounted in the housing and having multiple air port nozzle openings provided in an annular ring mounted between the grinding table periphery and the housing wall, and roller means contacting the grinding table upper surface for pulverizing the particulate material thereon, wherein the improvement comprises providing the annular air port ring containing multiple nozzles each being directed upwardly at an angle of 20.degree.-90.degree. with the horizontal plane with at least two adjacent air jet nozzle flow passageways each having a central axis which is oriented relative to said ring and rotary table so as to intersect at a point above the ring and provide an included angle within a range of 20.degree.-90.degree., whereby the air jet streams from said adjacent nozzles intersect and acoustic vibrations induced within the mill during operations are substantially eliminated by intense interaction of the intersecting air flow streams within the mill housing.
A solids pulverizer mill assembly for pulverizing coarse particulate materials, the mill including a housing, a rotary grinding table mounted on a speed reducer and motor in the housing and having multiple air port openings provided in an annular air port ring mounted between the grinding table periphery and the housing wall, and multiple roller means contacting the grinding table upper surface for pulverizing the particulate material thereon, wherein the improvement comprises providing the annular-shaped air port ring with 16-36 nozzle passages each having cross-sectional area of 10-50 in.sup.2 and in which multiple pairs of the air flow nozzles have central axis which are oriented upwardly relative to the ring and rotary table plane at an angle of 20.degree.-90.degree. and to intersect at a point above the ring and have an included angle of 20.degree.-90.degree., whereby the air jet streams from said adjacent nozzles intersect so that acoustic vibrations induced within the mill during operations are substantially eliminated by the intense interactions of the intersecting air flow streams within the mill housing.
A process for pulverizing coarse particulate solid material in a pulverizer mill to produce fine sized solids, comprising the steps of:
A process for pulverizing coarse particulate coal in a pulverizer mill to produce fine sized coal particles, comprising the steps of:
Dependencies are inferred from the claim text.