Chemical Engineering Research & Design, Vol.166, 10-17, 2021
Study on the flow field of cluster-six nozzles injector in an entrained flow gasifier model
As one of the key equipment of a gasifier, the injector unit of a gasifier has significant impacts on its flow filed, and further, the performance of gasifier. With the growth demand for higher gasification efficiency, new gasifier injector designs were kept being invented. In this paper, a pilot cluster-six nozzles (CSN) injector was designed and implemented on a simplified non-ignited entrained flow gasifier model in order to exam its performance, the formulated flow fields were compared with traditional single nozzle injector, results showed that the mean velocity profile along radial direction for CSN injector was similar to a Gaussian curve. Several equations based on the assumption of free turbulence flow were proposed in order to analyze the characteristics of the flow field. Compared with single nozzle injector, the centerline mean velocity of CSN injector decay more serious, which could reduce the gasifier volume about 50%, and the flow features, for example: the flow rate and the half-thickness under the same experiment conditions and cross section are about twice as much as in the single nozzle injector, and energy dissipation rate were also became faster. Experiment results also showed a better particle dispersion effect from the CSN injector, that the solid particles ejected from CSN injector were occupying more gasifier space and kept a longer residue time in gasifier, which could cause larger overall rate for gasification reaction and carbon conversion rate. These results indicated that the CSN injector can effectively improve the gasification performance and also provide more information for new gasifier injector design. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.