100 t/h Cross-beam Type Grate

Product introduction

The cross-beam grate is a new type of cross-beam grate bar with inclined air outlets applied to the cross-beam grate bar. Unlike the existing grate bars, whose air outlets face vertically upward, the air outlet direction of the vent holes in the inclined-outlet cross-beam grate bar forms a certain angle with the vertical direction. When the grate air leaves the grate bar it has a horizontal velocity, which is conducive to the horizontal diffusion of the air in the coal bed, enhances the mixing effect of coal and air, and reduces the phenomenon of coal leaking through the grate.

Scope of application and requirements

Scope of application

The cross-beam grate is a mechanized layer-burning device with a compact structure. The cross-beam grate is suitable for boilers with an evaporation capacity of 20~40 t/h and above. Its main structural difference from the chain-belt grate is that many rigid cross beams are used. The grate bars are installed in the corresponding grooves of the cross beams, and the cross beams are fixed on the transmission chains. There are generally two transmission chains (when the grate is very wide, several chains can be installed), driven by the chain wheels installed on the front shaft (drive shaft).

It is widely used in various large boilers and in special equipment such as heating and drying. It is suitable for burning bituminous coal, lignite and peat; specially designed incineration equipment can also burn other fuels such as bagasse and various kinds of waste.

Operating requirements

The medium used by this grate must meet the following requirements:

(1) The maximum particle size of the coal must not exceed 40mm, the content of 05mm coal fines must not exceed 50%, and the content of 030mm coal fines should be less than 25%.

(2) The moisture content of the coal is less than 20%, and 8~12% is the best.

(3) The ash content of the coal should be less than 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 higher than 1250℃.

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

(6) The net calorific value of the coal should be higher than 4350kcal/kg.

(7) If the above medium requirements conflict with the medium requirements of the coal feeding equipment, the highest requirement shall be taken.

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

Structure and characteristics

The whole grate is composed of the following components: (1) support; (2) grate chain; (3) ash removal device; (4) side seal; (5) air inlet pipe; (6) rear guide block; (7) front air baffle device; (8) shaft assembly; (9) coal hopper assembly.

(1) The support is composed of left and right wall plates and front, middle and rear cross beams. Between the cross beams, the ash removal device and the air chamber partition plates, several relatively closed air chambers of large capacity are formed; in this way the air intake of each area on the grate surface can be adjusted, and full combustion of the fuel is achieved.

(2) The chain is composed of chain links passing through rollers, intermediate guide blocks, chain shafts, retaining rings, pin shafts, etc. Bolt slots are cast on the chain links, and the cross beams are fixed by bolts.

(3) One end of the grate is driven by the drive shaft without a driven shaft, and a guide device is installed at the other end; the transition of the chain between the upper guide rail and the lower guide rail is completed by the drive shaft and the guide device. The drive shaft torque is provided by the grate reducer through a coupling.

(4) The side seal is a horizontal right-angle flow channel type side seal, which works together with the side seal of the grate bar; the two sealing lines improve the safety and reliability of operation.

(5) The ash removal device is of the push-pull type; by pushing and pulling the handle of the ash removal door and opening the ash removal door, the fine ash and coal fines collected in the air chamber can be discharged.

(6) The layered coal feeding device is widely used in the coal hopper device; the coal entering the furnace is loosely layered and fully burned, which improves the thermal efficiency of the boiler.

(7) The grate has a compact structure and a reasonable layout; the grate chain moves in the sealed guide rails, is not subjected to high temperature, and only bears the moving tension of the grate; the grate made of heat-resistant material contacts the high-temperature burning coal bed on the cross beams, and bears no stress when heated, thus prolonging the service life of the grate.

(8) The grate has no rear shaft and no eagle iron, which reduces the failure rate of the rear part of the grate during operation and improves the operating efficiency.

(9) The grate chain runs in a tensioned state, without arching or chain climbing; the movement of the chain is rolling friction, the running torque requirement is low, and the noise is low.

(10) The overall sealing of the grate is good; air leakage and air cross-flow between air chambers can be prevented. The air intake of each air chamber can be adjusted separately, which is convenient and practical.

(11) The grate surface is flat, the grate bars overlap each other and are closely arranged, which can prevent coal leakage and coal dropping; the grate bars can be replaced conveniently without stopping the boiler.

Model parameters

Operating features

1. Good structural rigidity, the grate bars are not heated, and the cross beams and chains are not heated either, so it is safer and more durable;

2. The effective area of the grate is large, the resistance is small, and the air volume distribution is uniform;

3. The movement of the chain is rolling friction, the running torque requirement is low, and the friction noise is small;

4. The overall sealing of the grate is good, which can prevent air leakage and air cross-flow between air chambers, and the air intake of each air chamber can be adjusted separately, which is convenient and practical;

5. The grate surface is flat, the grate blocks overlap each other and are closely arranged, so coal leakage and coal dropping are not easy to occur, and the grate bars can be replaced conveniently without stopping the boiler;

6. The ventilation section area of the grate is large, generally up to 10%-17%, and the combustion is extremely full;

7. The grate has no rear shaft and no eagle iron, so the rear part of the grate is not prone to failure in the furnace.