Mechanism of achieving a dense downer: Modeling and validation

被引：11

作者：

Chen, Hengzhi ^{[1
]}

Li, Hongzhong

Tan, Shiyu

机构：

[1] Chongqing Univ, Coll Chem & Chem Engn, Chongqing 400044, Peoples R China

[2] Chinese Acad Sci, Inst Proc Engn, Multiphase React Lab, Beijing 100080, Peoples R China

来源：

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH | 2006年 / 45卷 / 10期

关键词：

D O I：

10.1021/ie0509488

中图分类号：

TQ [化学工业];

学科分类号：

0817 ;

摘要：

A pressure balance model for a circulating fluidized bed (CFB) unit that incorporates a downer has been proposed. A comparison of the operation stability between a CFB downer and a CFB riser showed that, although only one critical operating gas velocity exists in the CFB riser for a given riser solids flux, there can be many critical gas velocities for the operation of a CFB downer. Therefore, it is possible to achieve high solids concentration in a CFB downer if appropriate operating conditions are used. Parameters that affect the solids concentration in the CFB downer have been studied using the model and have been validated with experimental data obtained from a special CFB unit that incorporates a downer. Measures to increase the solids concentration in the downer have been proposed.

引用

页码：3488 / 3495

页数：8

共 22 条

[1] Analysis of the overall pressure balance around a high-density circulating fluidized bed [J].

Bai, D ;

Issangya, AS ;

Zhu, JX ;

Grace, JR .

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, 1997, 36 (09) :3898-3903

[2] An analysis of loop seal operations in a circulating fluidized bed [J].

Basu, P ;

Cheng, L .

CHEMICAL ENGINEERING RESEARCH & DESIGN, 2000, 78 (A7) :991-998

[3] STATIC INSTABILITY ANALYSIS OF CIRCULATING FLUIDIZED-BEDS AND CONCEPT OF HIGH-DENSITY RISERS [J].

BI, HT ;

ZHU, JX .

AICHE JOURNAL, 1993, 39 (08) :1272-1280

[4] COMPUTER-SIMULATION OF THE PERFORMANCE OF FLUID CATALYTIC CRACKING RISERS AND DOWNERS [J].

BOLKANKENNY, YG ;

PUGSLEY, TS ;

BERRUTI, F .

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, 1994, 33 (12) :3043-3052

[5] Characterization of downflowing high velocity fluidized beds [J].

Cao, CS ;

Weinstein, H .

AICHE JOURNAL, 2000, 46 (03) :515-522

[6]

CHEN B, 1993, ENG CHEM METALL, V14, P252

[7]

Chen HZ, 2005, Circulating Fluidized Bed Technology VIII, P181

[8] Two-phase structure in a high-density downer [J].

Chen, HZ ;

Li, HZ ;

Kwauk, M .

POWDER TECHNOLOGY, 2005, 158 (1-3) :115-123

[9] Characterization of a high-density downer reactor [J].

Chen, HZ ;

Li, HZ .

POWDER TECHNOLOGY, 2004, 146 (1-2) :84-92

[10] Distance and prediction error variance constraints for ARMA model portfolios [J].

Chenoweth, T ;

Dowling, K ;

Hubata, R ;

St Louis, R .

INTERNATIONAL JOURNAL OF FORECASTING, 2004, 20 (01) :41-52

← 1 2 3 →