A wood pellet fuel manufacturer in Jilin, which processes 200,000 tons of forestry waste annually, originally used coal-fired hot air furnaces to dry pine sawdust (moisture content 55%→10%), but faced problems of high pollution and high costs. Based on actual problems, a biomass boiling furnace was used as a heat source to achieve energy self-sufficiency and green production.
1. Breakthrough in fuel adaptability
Direct combustion of irregular waste materials such as high-humidity wood chips (moisture content ≤ 65%) and bark, through boiling suspension combustion technology (850~900℃ bed temperature), the fuel calorific value utilization rate reaches 92% (traditional grate furnace is only 75%).
2. Efficient output of heat source
The combustion produces 900℃ high-temperature flue gas, which is directly introduced into the dryer heat exchange system after the fly ash is captured by the built-in cyclone separator:
First-stage heat exchange: flue gas is cooled to 220℃ and air is heated to 180℃ (main drying area)
Second-stage heat exchange: tail gas preheats wet wood chips at 180℃ (pre-drying area), and thermal efficiency is increased by 35%
3. Ash recycling
The bottom ash of the boiling bed (containing unburned carbon <3%) is transported to the mixing system through the spiral slag discharger as a binder for pellet fuel to achieve zero solid waste emissions.
This case proves that using a biomass boiling furnace as a heat source can reduce cost consumption to a greater extent and better control the drying temperature of wood chips to prevent coking.