Research And Application Of Carbon Powder Movement Law In Laminar Entrained Flow Reactor

The laminar entrained flow furnace could be used to study the devolatilization characteristics of solid particles, it can achieve rapid heating rate, the maximum heating rate up to 105 K/s, high-temperature conditions of laminar entrained flow furnace has been successfully applied to the study of biomass devolatilization characteristics at flash heating rate.This article was for the investigation of biomass pyrolysis product flow characteristics in a laminar entrained flow furnace. in order to obtain more reasonable experimental parameters of devolatilization characteristics,the velocity distribution of carbon particles in a reaction tube were then determined using PIV technique.To achieve a stable feeding at very low feeding rate in a laminar entrained flow furnace, a new type of biomass powder feeder was developed, in which the biomass powders fluidized by a vibrating motor are pneumatically carried into the reactor. The feeder can feed the biomass powder continuously and stably at the feeding rate of 0.039g/min.In order to solve the problem of experimental conditions change during the study process, designed a automatically move control device of camera in PIV system, and compared the experimental results which were obtained before and after using the device, greatly improved the experimental efficiency and accuracy of experimental data.The experiment used carbon particles (100～125um) as raw materials, the experimental factors which have four different collection distances and each of them have four main air flow, a measurement of flow velocity distribution was carried out by using of PIV technique. Summarized rate change of carbon particles in the reaction tube, And analysis of the main air flow and the collection of cases from their impact were also summarized as follows:with the increase of collection distances, particles from the center of the pipe section of the axial velocity decreases, while increase with the main flow.Experiment measured residence time of carbon particles in the vertical tube show linear relationship with the Reynolds number. After stress analysis of carbon particles, using Newton formula calculated the theoretical value of carbon particles residence time. carbon particles by the feeding tube into the vertical tube which was impetus by the flow received then obstruction. Combined with dynamic formula, the position of carbon particles speed change can be get. Respectively:(H=6.1mm, H=13.7mm, H=24.0mm, H=36.9mm) After the carbon particles reach the critical point was carried by the main flow and then through vertical pipe with laminar flow. The movement law tally with experimental result. Under different collection distances, the ratio of theoretical and experimental values of the residence time show linear relationship with the Reynolds number. These results could be in support of the thermal state pyrolysis devolatilization study in laminar entrained flow furnace.