Novel full-automatic pulverized coal return device with two-stage axial separators of medium-speed coal mill

Abstract

The invention provides a novel full-automatic pulverized coal return device with two-stage axial separators of a medium-speed coal mill. The novel full-automatic pulverized coal return device comprises an upper-stage axial separator, a pulverized coal storage tank and a lower-stage axial separator from top to bottom in sequence, wherein the vertical deflection angle of a baffle plate A is greater than that of a baffle plate B; small-particle pulverized coal is separated from large-particle pulverized coal through the lower-stage axial separator, and spirally ascends to the lower part of the upper-stage axial separator in an accelerated manner; qualified-fineness pulverized coal in the small-particle pulverized coal can be separated from unqualified-fineness pulverized coal through the upper-stage axial separator, spirally ascends in an accelerated manner, and leaves through a pulverized coal outlet pipe; the unqualified-fineness pulverized coal is attached to the inner wall of a body due to centrifugal force, and then slides into the pulverized coal storage tank along the inner wall; the unqualified-fineness pulverized coal falls onto a millstone along the trend of the pulverized coal storage tank through a peak valley, a pulverized coal return pipe and the inner wall of an inner cone; the upper-stage axial separator and the lower-stage axial separator are low in resistance, high in separation efficiency and more uniform in pulverized coal outlet fineness; and the unqualified pulverized coal returns to the millstone through the pulverized coal storage tank to be ground again, so that the thickness of the pulverized coal on the millstone is increased, and the vibration of the coal mill is reduced.

Description

technical field [0001] The invention relates to the technical field of pulverized coal separation equipment in coal-fired power plants, in particular to a novel fully automatic pulverized coal return device for a medium-speed coal mill double-stage axial separator. Background technique [0002] my country's current power generation mainly comes from coal-fired thermal power generation, accounting for more than 70% of the total power generation. The raw coal is ground into coal powder by a coal mill, and the qualified coal powder enters the furnace through the powder pipe through the hot primary air for combustion. The working principle of the medium-speed coal mill is that the raw coal passes through the center of the grinding plate of the coal falling pipe, and at the same time, the hot air enters the mill from the air inlet. With the rotation of the grinding table, the raw coal moves to the edge of the grinding table under the action of centrifugal force, and is crushed b...

AI Technical Summary

Problems solved by technology

The main separation principle of the radial separator is simple baffle separation. When the pulverization system uses the radial separator, many separators have large resistance, low separation efficiency, high cycle rate, low uniformity of pulverized coal, and pulverized coal. Many problems such as inconvenient fineness adjustment, coarse coal fineness or easy clogging, serious pipeline wear and low overall efficiency make the operation of the equipment unsafe and uneconomical

[0004]In addition, due to the high wind speed of the wall-adhering wind inside the medium-speed coal pulverizer, the unqualified coal powder coming out of the separator cannot follow the medium-speed pulverized coal. The wall surface of the machine body falls back to the grinding table for secondary grinding, and at the same time, the thickness of the pulverized coal on the grinding table is thinner, causing the vibration of the coal mill, which seriously affects the safe and economical operation of the medium-speed coal mill

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