Design And Simulation Of Screw Drum Biomass Continuous Pyrolysis Device Feeder

Biomass is considered as one of the potential energy resources that can maintain the energy and environmental sustainability mainly due to its abundance andCO ₂ neutrality.Thus,the development and utilization of biomass energy has risen more and more attention.There are many kinds of biomass which is cheap distributing in china widely.Biomass is a kind of renewable energy with great potential for development and utilization.Biomass continuous pyrolysis technology is one of the most promising technologies for utilizing biomass.And it has a lot of advantages.The device applied in biomass continuous pyrolysis technology is simple in design and manufacture.The condition of biomass continuous pyrolysis is easy to control.What’s more,the most important features of biomass continuous pyrolysis technology are that it can convert biomass into energy product without pause.As a core component of biomass continuous pyrolysis device for biomass,feeder of biomass has a fundamental influence on the performance of biomass continuous pyrolysis device.To solve the problem of existing feeder applied in biomass continuous pyrolysis,this paper presents a new feeder structure adopting the structure combining screw and drum.What’s more,a screw drum continuous biomass pyrolysis device whose handling capacity is 8kg/h has been designed and manufactured.Its main work principle of the de vice is that motor drives the drum and screw rotating,biomass in feed ing box is carried into the screw drum reactor under the function of shaftless spiral blade,biomass moves forward continuously at the function of screw blade and biomass is pyrolyzed at the same time.The main structural dimensionsare:Diameter of spiral bladeD₁=150mm,Inner diameter of spiral blade d₁=48mm,Pitch S₁=140mm,Diameter ofdrumD₂=168mm,Wall thicknessδ₂=8mm,Length of drumL₂=1500mm.The results of transportation experiments show that the feed amount is related to the stacking density of biomass.The larger the stacking density is,the larger the feed amounts are.Compared with the theoretical calculation of the feeding amount,the actual feeding quantity is lower.The actual feeding quantity of Camellia shell is about 43%of the theoretical calculation value,and pine nut shell is about 39%.This is mainly due to that the filling rate chosen in theoretical calculation is larger than the actual filling rate.How the particles motion in the spiral drum has been simulated with the help of EDEM softwarebased on the discrete element method to analyzethe performance of the spiral drum feeder in terms of particle speed and the number of pellets delivered.The conveying experiments were carried out on the spiral drum feed made of plexiglass.In addition,the changes in performance are analyzed due to the changes in the operating conditions,such as the roller speed of spiral drum,the friction coefficient between the spiral blade and the particles,the friction coefficient between the drum wall and the particles,the friction coefficient between particles,filling ratio and other factors on the material movement.The particles flow in the feeder’s opening circularly in the process of conveying.Feeding volume of spiral drum feeder increase with the increase of spiral drum feeder’s rotating speed.However,the number of particles delivered by the spiral drum rotating 1 round decreases withthe increase of spiral drum feeder’s rotating speed.The friction coefficient between the spiral blade and the particles,the friction coefficient between the cylinder wall and the particles,the friction coefficient between particles have slight influence on the average axial velocity.Theaverage axial speed of particles decreases a little due to the increase of the friction coefficient between the spiral blade and the particles and the friction coefficient between the c ylinder wall and the particles.The average veloc ity of particles is linear with the friction coefficient between particles.The number of particles in the axial of spiral drum feeder gradually reduced.the filling rate in each section is 17.94%,23.42%,30.58%,45.18%,79.14%,89.91%under the condition that the friction coefficient between particles and the spiral blade and the friction coefficient between particles and the cylinder wall are 0.25,the coefficient of friction between particles is 0.5,the spiral drum speed is15rpm,charging rate was 1500pic/s.Model predictions are compared with experimental data showing a good match.