1996 Fiscal Year Final Research Report Summary
Development of fluidized-bed cement calcination process with energy conservation and low pollutant generatic
| Project/Area Number |
06558066
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 試験 |
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| Research Field |
エネルギー学一般・原子力学
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| Research Institution | University of Tokyo |
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Principal Investigator |
YOSHIDA Kunio Univ. of Tokyo, Fac. of Eng., Professor, 大学院・工学系研究科, 教授 (70010808)
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| Co-Investigator(Kenkyū-buntansha) |
SAKURAI Makoto Univ. of Tokyo, Fac. of Eng., Assistant research, 大学院・工学系研究科, 助手 (60262052)
TSUTSUMI Atsushi Univ. of Tokyo, Fac. of Eng., Associate Professor, 大学院・工学系研究科, 助教授 (00188591)
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| Project Period (FY) |
1994 – 1997
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| Keywords | Fluidized bed / Cement process / Spouted bed / Solids circulation / Scale-up |
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| Research Abstract |
Results are classified into two subjects : (1) elucidation of solids circulation mechanism in spouted beds and (2) development of a scale-up method for fluidiized-bed cement production process.
(1) Characteristics of particle circulation in a spouted bed with a draft tube
The proposed cement production process using fluidization consists of two-stage fluidized beds. : one is upper spouted bed for granulation and the other is lower fluidized bed for calcination. In order to complete the calcination at 1300ﾟC without agglomeration trouble it is essential to produce homogeneous-sized granulus at the upper spouted bed.
With this view a spouted bed of 0.205m diameter with a draft tube has been used to study the effect of gas velocity on the behavior of solids circulation. Based on visual observation using a borescope and the analyzes of pressure fluctuation and optical signals it was found that solid particles move from annulus into gas jet to from clusters periodically and are carried upward in the draft tube. At a certain maximum gas velocity, however, solids flow becomes homogeneous and are transported upward without cluster formation.
(2) Scale-up of an innovative fluidizd-bed cement production process
A pilot-plant with 20 tons per day was scaled up to a larger plant having the capacity of 200 t/d. In this scale-up process the principal specifications of main equipments could be designed on the basis of heat-balance calculation. Both granulating and calcinating beds were scaled up by enlarging their diameters twodimensionally, but several modifications were needed to achieve smooth operation.
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