45t/h Reciprocating grate
We supply the 45t/h reciprocating grate in an inclined air-cooled arrangement, driven hydraulically. The moving grate bars and the fixed grate bars are stacked alternately in steps. The inclined air-cooled design increases furnace volume, which helps volatile matter burn and lets fuel with a high biomass content tumble freely in the preheat zone.
Structure and air-cooled arrangement
The grate consists of the coal hopper, frame, moving beams, fixed beams, moving and fixed grate bars, front air baffle and drive system. The fixed grate sits on the fixed beams, which are fastened to the grate frame. The moving grate is set into the moving beams, which are mounted on a moving frame connected by a linkage to the external drive. When the motor starts, the linkage pulls the moving frame through the reducer so that the moving bars travel back and forth over the fixed bars; the stroke is set by the bar dimensions and the coal quality and is normally 70-180mm.
Fuel and operating requirements
The grate imposes the following quality requirements on the coal fed to the furnace; if the coal falls outside these ranges, operating parameters must be adjusted.
| Item | Requirement |
|---|---|
| Maximum coal lump size | Not more than 40mm |
| Share of 0-6mm fines | Not less than 50% |
| Content of 0-3mm coal | Less than 25% |
| Moisture content | Less than 15%, preferably 5-10% |
| Combustion ash | Not less than 10% |
| Ash melting point | Preferably above 1200℃ |
The grate can serve boilers from 1t-200t/h and accepts a wide range of fuels.
Model parameters
The table below gives the effective grate area, effective width, air-flow section ratio and drive shaft torque for common boiler evaporations.
| Boiler evaporation capacity | Effective grate area m² | Effective grate width mm | Air-flow section ratio | Drive shaft torque N.m | Inclination |
|---|---|---|---|---|---|
| 4 t/h | 5.56 | 1600 | 6-8% | 2000 | Customised to user requirement |
| 6 t/h | 6.08 | 1600 | 6-8% | 3000 | Customised to user requirement |
| 8 t/h | 8.5 | 2100 | 6-8% | 4000 | Customised to user requirement |
| 10 t/h | 12.99 | 2020 | 6-8% | 5000 | Customised to user requirement |
| 15 t/h | 22.04 | 3300 | 6-8% | 7500 | Customised to user requirement |
| 30 t/h | 29.65 | 3730 | 6-8% | 30000 | Customised to user requirement |
| 40 t/h | 40 | 4630 | 6-8% | 40000 | Customised to user requirement |
| 65 t/h | 60.16 | 7020 | 6-8% | 60000 | Customised to user requirement |
| 100 t/h | 99.56 | 10480 | 6-8% | 75000 | Customised to user requirement |
| 130 t/h | 100 | 11580 | 6-8% | 100000 | Customised to user requirement |
| 160 t/h | 153 | 14700 | 6-8% | 125000 | Customised to user requirement |
| 200 t/h | 185 | 17780 | 6-8% | 150000 | Customised to user requirement |
| 260 t/h | 248 | 18400 | 6-8% | 185000 | Customised to user requirement |
| 300 t/h | 295 | 20700 | 6-8% | 210000 | Customised to user requirement |
The grate uses zoned air supply, with several independent air chambers along its length fed from wind boxes or ducts on both sides, and each chamber’s air volume is set by an adjusting device. Coal bed thickness is regulated by raising or lowering the coal gate, and the grate can be delivered as a complete unit or as separate parts.
Biomass fuel and operating control
The reciprocating grate is hydraulically driven, structurally stable and easy to adjust. The tumbling action and travel speed of the fuel in each zone can be controlled separately, so the residence time of the fuel in each zone can be set precisely and the biomass fuel burns out completely. Fuel with a high biomass content tumbles fully in the preheat zone, its surfaces receive radiation from the hot flue gas, moisture evaporates faster, and it burns steadily on reaching the combustion zone.
