4t/h Light Chain Grate Stoker

Product introduction

In a chain-belt grate, the chain belt itself forms the grate surface. The chain is driven by the sprocket, so that the grate moves slowly. The grate plates are usually made of cast iron. After assembly, the necessary ventilation gaps are kept between the grate plates, and an independent air chamber with adjustable air volume is usually provided under the grate, so that air can pass through the gaps into the fuel bed for combustion. Coal falls evenly onto the grate from the coal hopper at the front of 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 goes through ignition and combustion in sequence until it burns out. The ash and slag after combustion are discharged manually or mechanically. There is also a version that does not use a coal hopper to feed coal but instead uses a coal spreader to throw the coal to the rear of the grate, with the grate moving forwards. The moving speed of the grate is adjusted through gear transmission according to the coal type and the boiler load.

Scope of application and requirements

Scope of application

The chain-belt grate is a mechanized layer-firing unit that can be used for boilers with an evaporation capacity of 1-25t/h, and also 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 materials such as bagasse, wood and rice husk.

Operating requirements

The coal 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%, with 8-10% being 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 of the coal should be higher than 1290℃.

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

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

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

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

Structure and characteristics

Components: 1. driving shaft; 2. driven shaft; 3. support frame; 4. ash discharge device; 5. air regulating device; 6. grate chain; 7. coal hopper; 8. front air baffle plate; 9. side seal.

(1) The structure is simple, the metal consumption is low and the ventilation section ratio is large; relatively high strength and performance requirements are placed on the driving shaft, the driven shaft and the grate plates.

(2) Inside the grate, several mutually isolated independent air chambers are arranged along the length. 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 supply of each air chamber can be adjusted through the air regulating device.

(3) Each air chamber is fitted with an ash discharge device. At the bottom of the air chamber there is an ash drop base plate with an ash drop opening, and a movable door connected to the ash drop pull rod normally covers the ash drop opening. When the ash discharge handle is pulled at regular intervals, the ash and slag fall from the ash drop opening onto the grate chain below, and the grate chain carries them to the front end or into an ash receiving hopper near the ash outlet door, where they are finally removed manually.

(4) The grate runs normally once commissioning has been completed at the partner factory; it can be shipped as a complete unit, or in separate parts as requested by the user.

Model parameters

Operating features

1. Compared with other chain-belt grates, it has low metal consumption and a simple structure, and is easy to manufacture, install and operate;

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