Pulverized coal furnace is a boiler equipment that uses pulverized coal as fuel. It has the advantages of rapid, complete combustion, large capacity, high efficiency, adaptability to a wide range of coals, and easy control and adjustment. The combustion characteristic of the pulverized coal stove is that the fuel enters the combustion chamber along with the air and burns in a suspended state.

The coal is ground into very fine coal powder in advance, and the contact surface area with the air is greatly increased to strengthen the combustion. The temperature in the pulverized coal furnace is also relatively high. Therefore, in addition to the poor coal, all kinds of coal can be effectively burned in the pulverized coal furnace. The combustion is relatively complete and the combustion efficiency is relatively high, about 88%- 93%. It can be fully mechanized and automated. Pulverized coal combustion is almost the combustion method of all large coal-fired boilers.

The combustion equipment of the pulverized coal furnace is mainly composed of a furnace, a burner, and an ignition device. The pulverized coal is transported by the primary air into the furnace through the burner, and the secondary air is introduced into the furnace through the secondary air circular duct or the secondary air port of the burner.

After the mixture of pulverized coal and air enters the furnace, it ignites and burns at a certain distance from the burner outlet after preheating, drying, and volatilization analysis. The ash formed after the pulverized coal is burned out. A small part of the ash with coarser particles forms ash, which falls into the cold ash hopper and cools into solid ash, which is periodically or continuously removed; most of the ash with finer particles It is taken away by smoke, and this part of ash is usually called fly ash.

The pulverized coal stays in the furnace for a short time, only 1-2s. To ensure that the pulverized coal is burned out in the furnace in such a short time, it is necessary to intensify the combustion and supply an appropriate amount of primary and secondary air to shorten the combustion preparation stage and create good combustion conditions. The main function of the primary air of the pulverized coal stove is to transport the pulverized coal to the furnace and ensure the ignition and combustion of volatiles. The role of the secondary air is to supplement the amount of air; the other is to make the pulverized coal and air mix uniformly to ensure complete fuel combustion. Therefore, in the operation, the ratio and mixing time of the primary and secondary air must be properly adjusted in order to reliably ensure the safe and economic operation of the boiler.

Its hearth is a large space enclosed by a water-cooled fireplace wall. Ground coal (particle diameter is about 0.05-0.1mm) and air are mixed with a burner and sprayed into the hearth for combustion. The combustion of pulverized coal is divided into pre-fire preparation phase, combustion phase and burnout phase. Corresponding to this, the furnace can also be divided into three areas: near the burner outlet is the ignition zone, above the exit is the combustion zone, and the upper part of the combustion zone up to the furnace outlet is the burnout zone. It is suitable for many kinds of coals. It can burn medium, sub-coal or low-calorific value and low coal, and it can also burn coal with strong cohesiveness. It is the main form of modern coal-fired boilers. It is especially suitable for large-scale boilers in power plants with relatively high capacity. Large (D≥35t/h) industrial boilers are also often used. Pulverized coal furnace needs to be equipped with coal grinding equipment and corresponding dust removal device, the organization of combustion conditions is more complicated, and there are many factors that affect combustion stability. The fly ash content of the pulverized coal furnace is as high as 80-90%, and it needs to be equipped with a high-efficiency dust removal device.