Structure and Function of Boiler Chain Grate

　　Chain GrateIt is a long-standing, reliable, and stable mechanical coal-burning device in industrial boilers, which has been widely used. Let's learn about the structure and function of the boiler chain grate!

　　Chain GrateStructure

　　The shape of the chain grate resembles a belt conveyor.

　　The operation process involves coal falling from the coal hopper to the front end of the grate under its own weight, slowly moving from front to back with the grate, passing through the coal gate into the furnace. The height of the coal gate can be freely adjusted to control the thickness of the coal layer. Air is drawn from the air supply chamber located below the grate, intersecting with the direction of coal layer movement. The coal is radiantly heated in the furnace, completing preheating, drying, ignition, combustion, until it is completely burned out. Ash moves to the rear with the grate, falling into the rear water-cooled ash hopper through the slag plate (commonly known as eagle iron), and is discharged by the slag removal machine.

　　Chain GrateIt is a lightweight grate suitable for boilers with an evaporation capacity of less than 10t/h. The grate plates are divided into active and passive grate plates, connected by round steel rods, forming a wide chain belt around the front sprocket and rear drum. Since the active grate bears the traction force that transmits the overall movement of the grate, its thickness is greater than that of the passive grate and is made of forged cast iron. In a boiler with an evaporation capacity of 4t/h, there are three active chains composed of active grates (on both sides and in the middle) directly engaging with the three sprockets on the front shaft. A large number can be made of ordinary gray cast iron with low strength since they are not subjected to tensile forces.

　　The advantages of the chain grate are: lower metal consumption compared to other chain grates, simple structure, and relatively convenient manufacturing, installation, and operation. The disadvantages are: a large number must be connected with round steel to ensure the quality of processing and assembly. Otherwise, they are prone to breakage, making inspection and replacement inconvenient; after long-term operation, due to severe wear of the large creek cypress, the gap increases, leading to increased coal leakage losses.

　　The shape of the grate is similar to a belt conveyor. Coal falls from the coal hopper onto the grate under its own weight, and as the grate slowly moves from front to back, the height of the coal gate is adjusted to control the thickness of the coal layer. The coal is radiantly heated in the furnace, completing preheating, drying, ignition, combustion, and finally burning out, with ash moving to the rear and falling into the ash hopper for discharge. There are many types of grates, generally divided into three types based on their structural types: chain belt, beam, and scale.

　　The above introduction is about the boilerChain Gratestructure and function. Due to the poor ignition conditions of the chain grate, coal ignition mainly relies on the radiant heat from the furnace flame and arch, so coal is ignited first and then gradually burns down. Generally speaking, after coal enters the furnace, as the grate slowly moves from front to back, it mainly undergoes residual heat and drying until the final combustion.