130t/h Cross-beam Type Grate

Product introduction

The cross-beam grate is a new type of cross-beam grate plate in which an oblique air outlet is applied to the cross-beam grate plate. Unlike existing grate plates, whose air outlet is directed vertically upward, the air outlet of the ventilation holes in the oblique-outlet cross-beam grate plate forms a certain angle with the vertical direction. When the grate air leaves the grate plate it has a horizontal velocity, which is conducive to the horizontal diffusion of the air in the coal seam, strengthens the mixing effect of coal and air, and reduces the phenomenon of coal leaking from the grate.

Applicable scope and requirements

Scope of application

The cross-beam grate is a mechanized layer-combustion 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 plates are installed in the corresponding grooves of the cross beams, and the cross beams are fixed on the drive chains. There are generally two drive chains (several may be installed when the grate is very wide), driven by the chain wheels mounted on the front shaft (drive shaft).

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

Use requirements

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

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

(2) The moisture content of the coal is less than 20%, with 8~12% being the optimum.

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

(4) The ash melting point temperature of the coal shall be above 1250℃.

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

(6) The net calorific value of the coal shall be above 4350kcal/kg.

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

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

Structure and characteristics

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

(1) The support frame consists 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 partitions, several relatively closed large-capacity air chambers are formed; in this way the air supply to each zone of the grate surface can be adjusted, and full combustion of the fuel is achieved.

(2) The chain consists 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 and needs no driven shaft, and the other end is fitted with a guide device; the transition of the chain between the upper guide rail and the lower guide rail is accomplished 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 passage type side seal, which works together with the side seal of the grate plates; the two sealing lines improve the safety and reliability of operation.

(5) The ash removal device is of the push-pull type; by pulling the handle of the push-pull ash removal door, the ash removal door is opened, and 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 assembly; the coal entering the furnace is loose and layered and burns fully, which improves the thermal efficiency of the boiler.

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

(8) The grate has no rear shaft and no tail guard 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 under tension, without arching or chain climbing; the chain movement is rolling friction, which requires low operating torque and produces low noise.

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

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

Model parameters

Operating features

1. The structure has good rigidity, the grate plates are not subjected to heat, and the cross beams and chains are not subjected to heat either, so it is safer and more durable;

2. The grate has a large effective area, low resistance and even air distribution;

3. The chain movement is rolling friction, which requires low operating torque and produces little friction noise;

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

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

6. The grate has a large ventilation section area, generally up to 10%-17%, and combustion is very complete;

7. The grate has no rear shaft and no tail guard iron, so the rear part of the grate is unlikely to fail inside the furnace.