8t/h Biomass Chain Grate

Product introduction

The chain belt of the chain-belt type grate itself forms the grate surface. The chain is driven by sprockets, which makes the grate move slowly. The grate plates are usually made of cast iron. After assembly, the necessary ventilation gaps are kept between the grate plates, and independent air chambers with adjustable air volume are usually provided below the grate, so that air can pass through the gaps into the fuel bed for combustion. The coal falls evenly from the coal hopper at the front end of the grate onto the grate, and the thickness of the coal bed is adjusted by raising and lowering the coal gate.

As the grate moves backwards, the coal bed completes ignition, combustion and finally burn-out in sequence. The ash and slag after combustion are discharged manually or mechanically. There is also a mode in which no coal hopper is used for coal feeding; instead, a coal thrower throws the coal to the rear part of the grate and the grate moves forward. The moving speed of the grate is adjusted through gear transmission according to different coal types and boiler loads.

Scope of application and requirements

Scope of application

The chain-belt type chain grate is a mechanized layer-firing unit that can be used for boilers with an evaporation capacity of 1-25 t/h, and can also be used for various heating and drying equipment. It is suitable for burning bituminous coal, lignite and peat. After special design, it can also serve as biomass fuel combustion equipment burning raw materials such as bagasse, wood and rice husk.

Use requirements

The coal quality burned by this grate must meet the following requirements:

(1) The maximum particle size of the coal must not exceed 40mm, and coal fines below 0-5mm are not suitable for burning.

(2) The moisture content of the coal should be less than 20%, and 8-10% is suitable.

(3) The ash content of the coal must not exceed 30%, but must not be lower than 10%, and the volatile matter content must not be lower than 20%.

(4) The ash melting point temperature of the coal should be greater than 1290℃.

(5) The caking property should not be too strong.

(6) The net calorific value of the coal should not be greater than 4226kcal/kg.

(7) If the above coal quality requirements conflict with the coal feeding equipment, the upper limit value shall be taken.

The primary air temperature used by this grate must not exceed 200℃.

Structure and characteristics

Component parts: 1. drive shaft; 2. driven shaft; 3. support; 4. ash discharging device; 5. air regulating device; 6. grate chain; 7. coal hopper; 8. front air baffle; 9. side seal.

(1) Simple structure, low metal consumption and a large ventilation section ratio; relatively high requirements are placed on the strength and performance of the drive shaft, the driven shaft and the grate plates.

(2) Several mutually isolated independent air chambers are arranged inside the grate along the longitudinal direction. After the primary air enters an air chamber, its flow velocity decreases due to diffusion and it can evenly fill the whole air chamber. The air intake of each air chamber can be adjusted through the air regulating device.

(3) Each air chamber is equipped with an ash discharging device. The bottom of the air chamber is provided with an ash dropping base plate with an ash dropping opening, and a movable door connected to the ash dropping pull rod normally covers the ash dropping opening. When the ash discharge handle is pulled at regular intervals, the ash and slag fall from the ash dropping opening onto the grate chain below, are then carried by the grate chain to the front end or into the ash receiving hopper near the ash discharge door, and are finally removed manually.

(4) The grate can run normally after debugging is completed in the partner factory, and can be shipped as a whole machine or in split parts according to user requirements.

Model parameters

Operating features

1. Compared with other chain-belt grates, the metal consumption is low, the structure is simple, and manufacturing, installation and operation are convenient;

2. The chain-belt grate runs reliably, burns stably and has wide fuel adaptability, and is widely used in industrial boilers.