Converting Waste Agricultural Biomass into a Resource - UNEP

The slotted cylinder, forming the inner wall of the reaction chamber, is of 5
mm thick mild steel sheet, with an open top and a grate welded to its base.
The cylinder has slots for air inlet and gas outlet, through which primary air
enters into the reaction chamber at one side, and the producer gas exits the
reaction chamber at the other side. The slots, six at each side, are provided
as illustrated in Figure 2.9.
A mild steel grate is welded to the base of the cylinder. The grate (Figure
2.10) is made of round mild steel rods of 12.5 mm diameter, and allows ash to
fall through it into the ash pit. An ash scraper (Figure 2.11) is fixed below the
grate, to remove ash accumulated inside the reaction chamber. The ash
scraper is especially useful while using fuels of high ash content, such as
ricehusk briquettes, since accumulated ash could otherwise block the flow of
fresh fuel from the fuel chamber into the reaction chamber.
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