The Design Of An Array Fast Pyrolysis Reactor And Its Fluidization Simulations

This paper focus on the design of an array fast pyrolysis reactor and its CFD simulations.The array fast pyrolysis reactor was designed with an annual processing capacity of 1,000 tons, not only the cold and hot state fluidization simulations of the single tube consist the array fast pyrolysis reactor was studied, but also the flow properties of the internal bed. The critical flow velocity, escape velocity, operating speed was calculated from the designed reaction parameters according to the knowledge of the fluidized bed. The single-tube height was determined by the expansion rate calculation and the operating speed. The volume of the single tube was calculated and the grid plate was designed. This paper emphasizes the study of the heat transfer of the bio-mass array fast pyrolysis reactor. The appropriate heating method was selected through the sin-gle-wall surface heat transfer calculations. The designed fast pyrolysis system takes full advantage of waste heat to support the operation of the system and dry the raw material. Two heat exchang-ers were designed. According to the energy balance calculation, the calibration error is 3.72%, the designed fast pyrolysis system is practical.The cold and hot state fuidization simulations of the single tube of the designed array fast pyrolysis reactor show that:the simulation results with a deviation of less than 10% agree well with the experimental results, it can actually reflect the complex fluid dynamics of the gas-solid; the cold state simulation reveals the change processes of the bubble formed in a single tube, this process include formation, development, fragmentation, jet formation, development, and disappear when the gas-solid inside the single tube achieve a steady state; the flow mass of the spout flui-dized bed was characterized by solid-phrase flow diagram, solid-phase velocity contour map and solid-phrase instantaneous velocity vector diagram inside the reactor; the critical flow velocity inside the single tube was obtained when the temperature was 550℃and the static bed height is 150mm. Innovations of this paper are as follows:A biomass fast pyrolysis reactor engineering amplification mode is provided. The array of biomass fast pyrolysis reactor is present at the first time which increasing the biomass fast pyroly-sis reactor to enlarge the number of methods without increasing the fast pyrolysis of biomass un-der the premise of the reactor size.The proposed furnacelygas one is provided firstly from the engineering point of view which cannot use the product of fast pyrolysis of gas condensate. The flue gas which comes from the reactor and the flow of gas have heat changes and then dry combination, in order to achieve as much as possible to maximize heat recovery and efficient use of energy.