Rotary nozzle ring capable of reducing ventilation resistance for medium-speed coal pulverizer

Abstract

The invention discloses a rotary nozzle ring capable of reducing ventilation resistance for a medium-speed coal pulverizer. The rotary nozzle ring comprises an inner side wall plate, an outer side wall plate, and a blade arranged between wall plates; the rotary nozzle ring also comprises a movable nozzle ring and a static nozzle ring, and the movable nozzle ring and the static nozzle ring are welded by using plates; the movable nozzle ring comprises the inner side wall plate, the outer side wall plate, the blade, a horizontal flange welded to the inner side wall plate and an annular top platewelded to the upper end of the outer side wall; the movable nozzle ring is fixed to a grinding disc of the medium-speed coal pulverizer; the static nozzle ring comprises an inverted conical tube, an annular bottom plate welded to the lower end of the conical tube and a welding connecting plate which is distributed at the periphery of the conical tube and extends out; the static nozzle ring is connected with the inner wall of a middle frame body through the welding connecting plate in a welding manner; and a gap is reserved between the annular bottom plate arranged at the lower end of the static nozzle ring and the annular top plate which is arranged at the upper end of the movable nozzle ring. The rotary nozzle ring capable of reducing ventilation resistance for the medium-speed coal pulverizer disclosed by the invention has the active effects that the ventilation resistance of the nozzle rings of the coal pulverizer is reduced, primary air formed at a spraying opening is more even, the air leakage amount produced between the movable and static nozzle rings is reduced, the residue discharging amount is reduced by 50 percent or above, and the overhauling and maintenance costs of thenozzle rings are reduced for users.

Description

technical field [0001] The invention belongs to pulverizing and crushing equipment, in particular to the components of medium-speed coal mills used in coal-fired thermal power plants, chemical plants or iron and steel smelting plants. Background technique [0002] The medium-speed coal mill equipment used in coal-fired thermal power plants, chemical plants or iron and steel smelting plants is mainly responsible for grinding raw coal into coal powder with a certain fineness requirement, and at the same time completing the drying process of coal powder and making the coal powder Transport to boiler furnace, gasification furnace or blast furnace for combustion. [0003] In the past, the nozzle ring composed of inner wall plate, outer wall plate, and inclined blades between the wall plates on the medium-speed coal mill is an integral casting and fixedly installed on the middle frame. Usually, the nozzle formed by the blade and its inner wall plate and peripheral plate is incline...

AI Technical Summary

Problems solved by technology

[0003] In the past, the nozzle ring composed of inner wall plate, outer wall plate, and inclined blades between the wall plates on the medium-speed coal mill is an integral casting and fixedly installed on the middle frame. Usually, the nozzle formed by the blade and its inner wall plate and peripheral plate is inclined. The direction is the same as the running direction of the coal mill (clockwise), and the included angle with the horizontal plane is 30°, which makes the body resistance of the coal mill larger, the time for the hot air to pass through the nozzle ring is longer, and the pulverized coal with qualified fineness is The inside of the coal mill is stagnated, and the ventilation efficiency of the nozzle ring is low, which affects the output of the coal mill

The nozzle of the nozzle ring blows directly to the roller bracket, aggravating the wear of the roller bracket guard plate, shortening the service life of the roller bracket guard plate, and affecting the normal operation of the coal mill; because the nozzle ring is supported on the middle frame by the support plate, and through the seal The rope seals the small gap between the nozzle ring and the middle frame. The fine particles driven by the hot air can directly blow to the asbestos rope, which makes the asbestos rope easy to be damaged, resulting in no seal between the static nozzle ring and the middle frame, which directly affects the passage of hot air. The air volume and pressure of the nozzle ring cause uneven wind speed at the nozzle ring and different degrees of blade wear, resulting in an increase in the amount of pebble coal slag discharged from the coal mill, and a lower service life of the nozzle ring blades, which increases the labor intensity of maintenance personnel and reduces Improve the work efficiency of maintenance personnel and extend the maintenance time of equipment

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