Analysis And Dispose On Coking Phenomenon Of Biochar Gasifier I Nternal Wall

In process of the two stage type biomass dry distillation-gasification power generation in this paper. The main problem that affects the industrialization of the gasifier is the problem of coking gasifier wall. Two stage gasification process can solve the tar produced by biomass gasification, but in two stage gasification process, biomass carbon is the raw material for gasification. Due to the differences in physical and chemical properties of the material and the biomass material. The existing structure of the gasifier can not be adapted to the raw materials.During operation, the biggest problem is the coking gasifier wall.Gasifier that was design and development based on the current universal biomass materials, has poor adaptability to biomass charcoal. The intrinsic combustion characteristics of biomass carbon causes the extremely easy to appear over temperature phenomenon.Therefore,the key to solve the problem of the coke of gasifier wall is,one side,that make the air distribution system more effective,and that make the material and the gasification agent full contact reaction completely. On the other hand,that make the ash discharging system of the gasifier can discharge the material in the gasifier smoothly,and the ash discharge process can not influence the reaction in the gasifier.on this basis we can optimiz the gasifier.In the process of optimization and improvement of fix bed gasifier,we optimize the air distribution system and the gasification process,Mainly include optimization and design of air distribution structure, the test of wind distribution structure.At the same time, in view of the slow burning rate of rice husk char, we used the high temperature gasification agent gasification process.After modification, the results showed thatfluidized effect and combustion efficiency of biomass carbon in the fluidized bed was not ideal,the material coke in fluidized bed gasifier is small granular coke,with the extension of reaction time Granular coke can accumulate and cause blockage of the gasifier body in the gasifier.In the improved design of the furnace wall coking of the fixed bed,We use the design model of van gasifier,the advantage of this design is the section of the furnace body is a rectangular structure, the length of the short side of the section of the gasifier is determined, according to the treatment and the dosage of the gasifier.A plurality of air inlet manifold are evenly arranged on both sides of the gasifier,a control valve is disposed in each intake manifold.the valve is used to regulate the inlet of gasification agent near the inlet amount.Under the combined action of multiple inlet manifold,Gasification agent can be evenly through the gasifier body. And in the reaction process in the gasifier,the amount of the gasification agent can be adjusted in one area of the gasifier,according to the change of temperature in this area.The temperature of the gasifier can be controlled effectively.In the design of modifying the coking of the fixed bed, the ash removal system is optimized; the helical structure in the ash removing process is likely to cause unbalanced ash removing, represented as the material in the gasifier following a helical feeding direction, the front-end material is expelled from the gasifier at first, and the rear-end material is expelled at last. To resolve this issue, a combined action ash removing structure featuring ejecting shaft and horizontal ash removing helix is established. At the same time, in order to enhance the temperature control when the gasifier is in working mode and to prevent over-temperature coking, a sub area row of ash removing structure is implemented therefore the gas removing process will not interfere the other sections in the gasifier.We tested the remodeled version of the gasifier with 100-hour durability test, and found that it runs smoothly. No signs of coking and clogging are found inside the gasifier. The upgraded design will meet the demand of industrialization.