What types of boiler grates are there?

　　Boiler GrateWhat types are there?

　　Boiler GrateIt is a part of a boiler or industrial furnace, used to hold solid fuel and burn it efficiently. The entire grate mainly consists of a frame and grate bars. The grate is usually made of cast iron. After assembly, necessary ventilation gaps are maintained between the parts, and an independent ventilation chamber with adjustable air volume is often set below the grate, allowing air to enter the fuel layer through the gaps for combustion. After burning, the ash is discharged manually or mechanically. Grates can be fixed, movable, reciprocating, vibrating, or bottom-fed.

　　First, there is the grate bar boiler grate, which is generally strip-shaped or plate-shaped, fixedly installed at the bottom of the furnace or combustion chamber by a surrounding frame. This type of grate can only have coal and ash added manually at regular intervals, resulting in high labor intensity and poor combustion economic efficiency.

　　Secondly, there is the movable boiler grate, which comes in two types: chain belt and chain type. The surface of the chain grate is the chain itself; the grate bars of the chain grate are fixed on the upper supports of the chain. Both chain belt and chain grates are driven by sprockets, causing the grate bars to move slowly. Coal evenly falls onto the grate from the coal hopper at the front end. The thickness of the coal layer is adjusted by the coal gate that rises and falls. When the grate moves backward, the coal ignites, burns, and is consumed. There are also methods that do not use a coal hopper, instead using a coal throwing machine to throw coal onto the rear of the grate, while the grate moves forward. The speed of the grate is adjusted through gear transmission based on the type of coal and boiler load. Chain grates operate reliably, have stable combustion, and are widely adaptable to fuels, making them widely used in industrial boilers.

　　There is also the reciprocating type.Boiler GrateThe reciprocating boiler grate consists of a set of fixed grate bars and a set of reciprocating movable grate bars, divided into stepped and horizontal types. The reciprocating motion of the movable grate bars gradually pushes the coal layer towards the rear for combustion, thus this type of grate has a wide adaptability to coal types. There is a small angle between the vibrating grate surface and the horizontal plane, and the grate bars vibrate regularly under the action of a motor and an eccentric wheel. During the vibration process, the fuel layer continuously moves towards the back of the furnace, allowing the burnt ash to fall into the ash pit at the end of the grate. The characteristic of this grate is its simple structure.

　　Finally, there is the trough-shaped structure boiler grate, which has a screw rod installed at the bottom of the trough, leading to the coal hopper outside the furnace. Coal is fed from the lower part of the coal hopper into the coal trough through the screw, entering the high-temperature combustion zone from the bottom up. When the ash exceeds the angle of repose, it is discharged to the sides by gravity. This grate structure is simple, but it has certain requirements for the particle size and moisture of the coal, generally only suitable for small industrial boilers with an evaporation capacity of less than 1 ton/hour.

　　These several types of grates are common types, and due to differences in structure and functionality, they are applied in different scenarios.