Coal powder uniform distributing device and coal milling machine

Abstract

The invention provides a coal powder uniform distributing device and a coal milling machine. The coal powder uniform distributing device comprises a diffusion speed reduction section, a cylinder bodystraight section and an outlet connecting section which are connected sequentially. An equal-ring-face uniform distributor and a flow arranging grating are installed in the cylinder body straight section. According to the coal powder uniform distributing device, coal powder airflow is dispersed at the initial stage, the speed is reduced, flow uniformizing is achieved in advance, the flow is distributed equally many times and mixed in a rotating manner in the cylinder body straight section, after the flow is arranged uniformly at the later period, the flow enters all coal powder pipes, the speed and the concentration of the coal powder airflow entering all combustors can be distributed more uniformly, and resistance is moderate.

Description

technical field [0001] The invention relates to the technical field of coal pulverizers, in particular to a pulverized coal divider and a coal pulverizer. Background technique [0002] In each burner of a large-capacity coal-fired boiler direct blowing pulverization system, the uniformity of pulverized coal is one of the important factors that determine the combustion conditions of the boiler. The uneven distribution of air powder among the burners will directly affect the ignition and stable combustion of the pulverized coal flow at the outlet of the burner, and the distribution of the combustion temperature of the boiler furnace section, which will further cause boiler slagging, furnace metal wall temperature, steam temperature deviation, and NOx The increase in emissions will also cause the corresponding burner to burn out, and even cause local reducing atmosphere to be strong, resulting in local high-temperature corrosion of the heating surface, tube explosion on the hea...

AI Technical Summary

Problems solved by technology

The uneven distribution of air powder among the burners will directly affect the ignition and stable combustion of the pulverized coal flow at the outlet of the burner, and the distribution of the combustion temperature of the boiler furnace section, which will further cause boiler slagging, furnace metal wall temperature, steam temperature deviation, and NOx The increase in emissions will also cause the corresponding burner to burn out, and even cause local reducing atmosphere to be strong, resulting in local high-temperature corrosion on the heating surface, tube explosion on the heating surface of the boiler, etc., seriously affecting the safety and economy of the unit operation

[0003] At present, the common pulverized coal dividers at home and abroad mainly include three types: diffusion type, radial grid type, and axial flow guide type. The diffusion type divider is installed at the outlet of the coal mill, and the pulverized coal is accelerated, Deceleration and residual rotation, enhanced disturbance mixing, this kind of equalizer has pulverized coal flow that is not effectively evened and evenly divided, and the inherent equalization effect is not good

The radial grid type equalizer is in the shape of a circular grid, and the pulverized coal flows evenly inside the grid. This kind of equalizer has uneven distribution of the pulverized coal flow, no disturbance mixing, and the equalization effect is not good.

When the axial diversion is conducted, the equalizer divides the pulverized coal flow into a number of slit flows by means of partitions, and then introduces two branch pipes crosswise. The pulverized coal has a certain flow and equal distribution inside the guide. There is current sharing in the device, and the sharing effect is not obvious

Images