Filtration Performance of Coal Pyrolysis Flying Char Particles in a Granular Bed Filter

Abstract

The filtration of flying char particles from coal pyrolysis vapors plays a very important role in enhancing yields and quality of pyrolysis oil. In this work, the performance of coal pyrolysis flying char particles in a granular bed filter (GBF) was studied in cold model experiments. A filtration model was developed using a macroscopic phenomenological method that describes the filtration of the GBF. The polynomial expression of the relative filter coefficient (F) and the nonlinear expression of the relative pressure drop ratio (G) were applied in the new model. The unsteady state of granular filtration was captured, demonstrating that the GBF performance could be predicted by the new model. Effects of superficial gas velocity, thickness of granular layer, and dust mass concentration on collection efficiency and pressure drop were analyzed. An excellent performance of the GBF was obtained and the total collection efficiency could reach a span between 98% and 99.9%. In the case of lower dust mass concentration, the total collection efficiency and pressure drop were slightly affected by the increasing dust mass concentration. The optimal operating conditions of the GBF were obtained: a superficial gas velocity of 0.2–0.6 m/s and a granular layer thickness of 0.07–0.11 m.

Optimization of structure parameters in a coal pyrolysis filtration system based on CFD and quadratic regression orthogonal combination and a genetic algorithm

“…The c 1 and c 2 are empirical constants. Zhou et al (2019) have obtained the empirical values of c 1 and c 2 .…”

“…It was proved that the separation efficiency was improved. The study of Zhan et al (2018) has found that the superficial gas velocity, thickness of the granular layer and dust mass concentration parameters have a significant influence on the collection efficiency and pressure drop. Yu et al (2018) have indicated that an increase in bed height and a decrease in granule size are beneficial for improving filtration efficiency.…”

Systematic and Robust Air Cleanser for Cleaning a Pollution Caused by the Rocket Stove

“…Predicting the gas flow rate is essential for good Filter design [33]. The average and maximum flow rate, temperature, moisture content, chemical properties such as dew point, corrosiveness, and combustibility should be identified prior to the final design.…”