Study On Upright And Continuous Biomass Carbonization Equipment

Under the background of the continuous emergence energy problems in the world,there has been a serious phenomenon of straw burning in China in recent years.Despite the abundant straw resources in China,incineration of straw not only results in the waste of resources,but also brings a series of social and environmental problems.Based on the previous research of our group,this paper designed a vertical moving bed biomass carbonization equipment for the crushed biomass particles.The device innovatively adopts smolder pyrolysis and indirect heating to provide heat for carbonization.This heating method shortens the warming time of the biomass,improves the carbonization efficiency,and promotes the production of biochar.In order to achieve continuous production,the device uses spiral augers,rotary grate and other mechanisms to realize the convenience of feeding and discharging automation.In order to increase the utilization of heat,a flue gas reuse pipeline was designed to increase the overall heat utilization of the equipment.The main work of this paper includes the following aspects:(1)The process of carbonization equipment was designed,which determined the design scheme of the vertical moving bed biomass carbonization equipment,the theoretical calculations and analysis of the parameters of the important components of the equipment were carried out,the processing drawings of the carbonization equipment were drawn,the equipment manufacturing process was completed,and the control box was designed and manufactured.(2)The overall assembly and empty vehicle tests were performed on the carbonization equipment.During the entire process,the equipment was easy to assemble and operated smoothly.The modular design of this equipment was easy to install and maintain at a later stage.Trial run test were conducted using sawdust and chaff,but the phenomenon of material arching was frequent,which affected the sustainability of the entire charring process.(3)The analysis of the problem of the equipment arching was conducted.The reforming of the feed section,furnace section and ignition equipment of the carbonization equipment was carried out,which solved the knotting problem of carbonization equipment,to a certain extent.The chaff is used as a carbonization test material.Using the modified carbonization equipment for testing: There are 34.15 kg of chaff raw material,the mass of carbonized product is 6.5 kg,and the mass fraction of carbonization is 21.46%.(4)The chaff raw material with moisture content of 10% was directly charred in the carbonization chamber and the temperature change of the chaff in the carbonization chamber was measured.After analyzing the temperature data,it takes about 1 hour for the inner shell to dry and 4 hours for the outer shell to dry.For fixed-bed carbonization equipment,if moisture is directly used for drying,the heat transfer efficiency is low.(5)In view of the low heat transfer efficiency in the carbonization chamber and the possibility of internal arching and other problems,it redesigned the internal structure of the charring section and provided a new solution.The ANSYS CFX was used to analyze the temperature and flow field of the combustion chamber inside and after the optimization of the carbonization chamber.It provides a basis for optimal design.