Chain Grate Coal-fired Boiler

The chain grate coal-fired boiler is currently the most widely used general heating equipment in industrial boilers. Mainly include hot water boiler, steam boiler, and thermal oil boiler. This boiler mainly uses small lumps of coal as fuel. The degree of automation is high. The following will introduce you to the specific situation of the chain grate coal-fired steam boiler.

Composition of Chain Grate Coal-fired Steam Boiler

The structure of the chain grate coal-fired boiler is the upper drum and the lower grate. The grate is composed of coal-scuttle, coal gate, reducer, grate piece, air duct, etc. The drum is composed of drum, rising tube, down tube, convection tube bundle, water wall, and header. If it is a single boiler, there will be smoke pipes on the boiler. The entire boiler frame will have a furnace arch, furnace wall, smoke-box, insulation layer, and outer packaging.

Combustion Characteristics of Chain Grate Boiler

The combustion method of chain grate.

The combustion of the chain grate is a moving fire bed combustion, and the fuel ignition condition is "limited ignition". The fuel enters the grate through the coal hopper, and the thickness of the coal seam can be adjusted through the coal gate. With the movement of the grate, it enters the furnace to start its combustion process. The burned cinder moves at the end of the grate along with the movement of the grate and is removed by the slag The machine is discharged to the designated location.

Chain Grate Combustion Process

The ignition of coal mainly relies on the radiant heat of the furnace flame and arch, so the coal above it ignites first, and after the coal enters the furnace, it gradually moves slowly from front to back with the grate. At the front of the grate is the new coal combustion preparation area, which mainly conducts coal preheating and drying. Then the volatilization was analyzed and started to enter the combustion zone. In the middle of the grate is the coke combustion zone. The temperature in this zone is very high. At the same time, the oxidation and reduction reaction processes are proceeding, and a lot of heat is released. At the back of the grate is the ash burnout zone, the remaining coke in the ash continues to burn, usually called coking.

Performance Characteristics of Chain Grate Coal-fired Boiler

Advantage

1. The thermal efficiency of the EPCB chain grate coal-fired boiler is above 82%. Excellent performance in the same boiler.

2. The system has a relatively high degree of automation, which can save more labor than a fixed grate hand-fired boiler.

3. Small tonnage boilers can be quickly assembled and shipped out of the factory, which is easy to install and can be put into production quickly.

4. The fuel price is cheap and the supply is sufficient, which is suitable for all countries and regions.

5. Burning coal type, low calorific value ≥17750J/Kg, volatile matter>38.5%, ash content ≤32.4% second-class bituminous coal.

Disadvantages:

1. Solid fuel will produce smoke and dust after burning, and it needs to be equipped with corresponding auxiliary equipment: dust collector, slag remover, and the purchase cost are relatively high.

2. Solid fuel will produce corresponding nitrogen sulfide. The relative pollution is higher than that of liquid gas fuel.

3. Labor is still needed when adding coal to the coal hopper.

Auxiliary Equipment for Chain Grate Boiler

Auxiliary equipment: electric control box, reducer, coal machine, water treatment, water pump, economizer, condenser, dust collector, slag remover, chimney, blower, induced draft fan. Steam boilers need to be matched with sub-cylinders. If it is a large boiler, a dosing device and sewage device are required.

Instrument valves: steam boilers need safety valves, water level gauges, pressure gauges, thermometers, etc. Other valve instruments need to be matched with different valves according to factory conditions.

If you have any questions about the boiler, please feel free to contact us.

Application of Chain Grate Boiler

Countries with relatively high coal reserves or relatively cheap coal prices will have an advantage. If you are in other countries where resources are relatively scarce, you can also choose this furnace type.

This boiler can be used in various industries. Including central heating, food, textile, paper, and other industries.

If you have any questions about the boiler, you can contact me at any time!

EPCB Boiler Engineer-Xiang Zhang.