High temperature cracking method and device for coke tar in domestic biomass gas-making furnace

The invention relates to a tar cracking method in high temperature. The method is that cracking pipe is set in the making gas furnace at the high temperature segment; by transporting pipes the gas with tar generated by making gas furnace is transported in the cracking pipe so that said gas flows in the cracking pipe; the cracking pipe and the gas flowing in it are heated to the high temperature so that the tar in gas is cracked in the high temperature; the purpose of decreasing or eliminating tar in gas is achieved. Experiments shows that in burning and gasifying process, a high-temperature zone exists in the furnace body of up-suck and down-suck fixed-bed making gas furnaces and the temperature is more than 1000DEG C. The tar in gas starts to crack in 600DEG C and more than 60% of tar can be cracked in 900DEG C. So the tar cracking method in invention not only decreases the tar content in biomass making gas furnace effectively but also improves calorie value of gas and decreases the environmental pollution.