Characteristics of clusters in the jet influence zone of riser--颗粒学报PARTICUOLOGY

Yan, Z., Fan, Y., Xu, J., Lu, C., & Xu, C. (2021). Characteristics of clusters in the jet influence zone of riser. Particuology, 55, 118-127. https://doi.org/10.1016/j.partic.2020.09.001

Characteristics of clusters in the jet influence zone of riser

Zihan Yan, Yiping Fan, Jun Xu, Chunxi Lu ^*, Chunming Xu ^*

State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering and Environment, China University of Petroleum-Beijing, Beijing 102249, China

10.1016/j.partic.2020.09.001

Volume 55, April 2021, Pages 118-127

Received 20 March 2020, Revised 10 April 2020, Accepted 2 September 2020, Available online 18 September 2020, Version of Record 3 February 2021.

E-mail: lcx725@sina.com; lcx725@aliyun.com; xcm@cup.edu.cn

Highlights

• Solid holdup inside clusters and its distribution range in jet mixing zone were obtained.

• Effect of jet velocity on the distribution of solid holdup inside clusters was analyzed.

• Advantages of downward jets were shown based on cluster characteristics.

Abstract

By analyzing solid holdup signals in the jet influence zone of risers, the characteristics of clusters were studied. The solid holdups inside clusters and their distribution ranges were calculated under the cases of both upward and downward feed jets. Moreover, the effects of the jet velocity on the cluster characteristics were analyzed. The solid holdups inside clusters have higher values and wider distribution ranges in the upward feed injection zone than in the downward zone, implying that the number of individual particles in a cluster is unstable under the influence of upward jets. For the case of downward jets, cluster formations in the jet influence zone of risers can more easily maintain stability, offering a better mixing environment for jets and particles. As the jet velocity increases, the solid holdups inside clusters in the riser wall of the upward injection zone increase accordingly, while the distributions of solid holdups inside clusters have no significant changes if the feed jets are downward. This phenomenon confirms that improved operational flexibility can be obtained if downward jets are mixed with the prelift gas–solid flow in risers.

Graphical abstract

Keywords

Riser; Cluster; Jet; Solid holdup

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