The importance of laser particle size analyzer in coal particle size detection(2)

  The importance of detecting particle size of coal powder

The fineness of pulverized coal is one of the factors that affects the incomplete combustion loss of the boiler. The finer the pulverized coal, the more complete the combustion, the smaller the carbon content of the fly ash, and the higher the boiler combustion efficiency. However, too fine pulverized coal will increase the power consumption of pulverized coal. Therefore, the optimal control of pulverized coal fineness is of great significance to guide the operation of coal mills, reduce energy consumption, and reduce pollution. In the process of pulverized coal preparation, the most critical equipment and the one that has the greatest impact on the particle size of pulverized coal is our coal mill. The feeding amount of the mill and the speed of the mill will affect the change of particle size. Whether the coal mill can operate normally and at the optimal speed is directly related to the efficiency of the coal mill, the quality and energy consumption of pulverized coal, and more directly affects the combustion efficiency of the boiler and environmental pollution, and these All of them are what enterprises care about and pursue under the increasingly fierce market competitiveness.

The particle size of pulverized coal also has a great influence on the ignition temperature of pulverized coal gas flow. The optimal pulverized coal concentration corresponding to the minimum ignition temperature at different particle sizes is very close, except that the minimum ignition temperature corresponding to the larger particle size is slightly higher; when the pulverized coal concentration is less than the optimal pulverized coal concentration, as the pulverized coal concentration As the concentration increases, the ignition temperature decreases. Under the same pulverized coal concentration, the larger the particle size, the higher the ignition temperature; when the pulverized coal concentration is greater than the optimal pulverized coal concentration, there is not much difference in the ignition temperature of different particle sizes, but when the particle size is small, the ignition temperature appears earlier. rising trend. It can be seen from the above that the heating rate of pulverized coal gas flow is inversely proportional to the particle size. For multiphase ignition at extremely low concentrations, the particle size of pulverized coal decreases, the heating rate accelerates, and the corresponding ignition temperature also decreases. For homogeneous ignition at lower pulverized coal concentrations, the pyrolysis rate is independent of particle size and is only proportional to pulverized coal concentration. Therefore, the smaller the particle size, the faster the pulverized coal gas flow heats up, starts pyrolysis earlier, and reaches ignition conditions faster at the same furnace wall temperature, which means a lower heating temperature is required.

As we all know, the finer the pulverized coal in thermal power plants, the better the combustion characteristics, and the easier it is for the pulverized coal particles to catch fire, burn and burn out, reducing incomplete combustion losses. In addition, the finer the particles, the easier it is to respond to the air flow, the fuel distribution in the furnace is even, and the combustion is stable, which is conducive to regulating the instability of combustion and uneven flame distribution in the furnace. The heat loss is small, but the smaller the pulverized coal particles, the power consumption increases. Feiyang suffered heavy losses. The general requirement is that the particle size is 0-3mm, and most 20-50um particles are uniform. Therefore, particle size measurement of pulverized coal has become an important reference method for both the preparation and combustion of pulverized coal.