Investigation on gas-solids hydrodynamics and matching enhancement in feedstock injection zone of double-level nozzle riser--颗粒学报PARTICUOLOGY

Yao, X., Xu, J., Fan, Y., Lu, C., & Sun, F. (2023). Investigation on gas-solids hydrodynamics and matching enhancement in feedstock injection zone of double-level nozzle riser. Particuology, 75, 165-176. https://doi.org/10.1016/j.partic.2022.06.002

Investigation on gas-solids hydrodynamics and matching enhancement in feedstock injection zone of double-level nozzle riser

Xiuying Yao ^a, Jun Xu ^a, Yiping Fan ^a *, Chunxi Lu ^a *, Fuwei Sun ^{a b}

a State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing, 102249, China
b China Kunlun Contracting & Engineering Co, Ltd, Beijing, 100037, China

10.1016/j.partic.2022.06.002

Volume 75, April 2023, Pages 165-176

Received 8 April 2022, Revised 1 June 2022, Accepted 2 June 2022, Available online 18 June 2022, Version of Record 24 August 2022.

E-mail: fanyipin2002@sina.com; lcx725@sina.com

Highlights

• The double-level nozzle riser is experimentally investigated.

• The injection zone is divided into the upstream flow, main flow and secondary flow control regions.

• Secondary nozzle jet gas presents a poor match to particles below the main nozzle.

• Secondary nozzle jet gas can improve the oil-catalyst match near the wall.

• Secondary nozzle jet gas can avoid the coking above the main nozzle.

Abstract

With the development of current energy economy, it is necessary to improve the product distribution of fluid catalytic cracking process, which is achieved by a riser reactor with double-level of nozzles. The new riser is constructed by adding a level of secondary nozzle 0.5 m below the main nozzle of traditional riser. This paper investigates the gas-solids flow and oil-catalyst matching feature based on the optical fiber and tracer technologies. According to the distribution of solids holdup, particle velocity and dimensionless jet concentration, the feedstock injection zone can be divided into the upstream flow control region, the main flow control region, and the secondary flow control region in the radial direction. The size of the regions is changed by the jet gas velocity and axial height. There is a poor match of secondary nozzle jet to particles below the main nozzle. The jet gas from secondary nozzles can improve the matching effect of oil-catalyst near the wall and reduce the probability of coking above the main nozzle.

Graphical abstract

Keywords

Gas-solids flow; Matching; Feed injection zone; Double-level nozzles; Riser

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