Particle Distribution and Pressure Drop in a Horizontal Two-pass Liquid-solid Circulating Fluidized Bed

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Abstract To promote the application of the fluidized bed heat-transfer and anti-scaling technology in the horizontal two-pass heat exchanger, a set of cold-model two-pass liquid-solid circulating fluidized bed heat exchanger with transparent horizontal tube bundle was designed and built. Water and polyformaldehyde particles were selected as the working media. The effects of the operating parameters, such as the amount of added particles (0. 50%-1. 25%) and circulation flow rate (6-11 m³·h^-1), on the particle distribution and pressure drop were investigated by using a charge-coupled device (CCD) and a differential pressure transmitter. Results show that the particle distribution in the upper tube pass is relative uniform, while that in the lower tube pass is nonuniform. The solid holdups in the upper and lower tube passes both increase along the gravitational direction. A "dead zone" with low solid holdup exists in the lower tube pass, which is not beneficial to the heat transfer enhancement and fouling prevention. With the increase in circulation flow rate, the non-uniformity of particle distribution in the upper tube pass fluctuates, but that in the lower tube pass initially rapidly increases and then gradually decreases. The non-u-niformity of particle distribution in the upper and lower tube passes fluctuates with the increase in the amount of added particles. The pressure drop ratio fluctuates with the increase in circulation flow rate and the amount of added particles, and the maximum pressure drop ratio is 18. 3% within the experimental range. The three-dimensional diagrams of the effect of the operating parameters on the particle distribution and pressure drop are established to determine the proper range of operating parameter.

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	Articles by authors
	Jiang Feng
	Wang Jinjin
	Qi Guopeng
	Liang Xu
	Han Nisha
	Li Xiulun

Keywords： particle distribution； pressure drop； liquid-solid circulating fluidized bed heat exchanger； horizontal two-pass

Received 2020-05-12;

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Jiang Feng, Wang Jinjin, Qi Guopeng, Liang Xu, Han Nisha, Li Xiulun.Particle Distribution and Pressure Drop in a Horizontal Two-pass Liquid-solid Circulating Fluidized Bed[J] Chemcial Industry and Engineering, 2021,V38(2): 30-38,68

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