Solar, Biomass and Hybrid Dryers - BioEnergy Discussion Lists

Telescopic chimney110 cmTop cover88 cm58.5cm φWater SealFixed chimney,10 cm φ22 cmGrate, with holesStand(optional)Figure 7.4: The charring drum(ii) Briquette MouldThe briquette mould is made up of mild steel. It consists of three parts: the bottomplate with nineteen protruding rods each 13 mm in diameter, outer cylindrical coverto fit the bottom plate, and a perforated plate to slide down along the rods into thecylinder, as shown in Figure 7.5.(iii) Charring ProcedureAll types of biomass materials can be used in a charring drum for char production. Ifthe biomass material is too loose (e.g.: pine needles, leaves, etc.), then they can bemade into small bundles of 7-10 cm diameter and up to 60 cm length. Dependingupon the type of biomass, about 40-100 kg of biomass can be carbonized in thecharring drum to get a yield of 25-35% char over a period of 2 - 3 hours.First, the conical grate with fixed chimney is placed inside the drum and thetelescopic chimney is placed over the fixed chimney as shown in Figure 7.4. One totwo kilograms of dried leaves or twigs are spread uniformly over the conical grate40