1987 Fiscal Year Final Research Report Summary
Studies on high degree continuous expression of a multi-stage screw press.
| Project/Area Number |
61550703
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
化学工学
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| Research Institution | Faculty of Engineering, Nagoya University |
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Principal Investigator |
MURASE Toshiro Department of Chemical Engineering, Nagoya University, 工学部, 助教授 (70023067)
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| Co-Investigator(Kenkyū-buntansha) |
IWATA Masashi Department of Chemical Engineering, Nagoya University, 工学部, 助手 (10151747)
IRITANI Eiji Department of Chemical Engineering, Nagoya University, 工学部, 助手 (60144119)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Expression / Continuous expression / Screw press / Screw-type die / Multi-stage screw press / Two separate driving system / Compression-permeability test / スクリュー押し出し |
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| Research Abstract |
Continuous solid-liquid separation for dewatering slurry to a high degree was studied in use of a screw press with two separate driving systems.
1) The high degree continuous expression of Brown coal was achieved by use of a screw type die, comprised of a constant pitch-constant depth type screw and an unperforated barrel. When the die was used,the highly compressed cake was throughly discharged from the press, though the die-resistance was great. Dehydration was dependent on the thread depth, the axial length, and the difference in helical angles between worm and die.
2) Further improvements of screw expression were achieved by using a two-stage deliquoring systems with different rotations of two worms. Two worms of different helical angles rotated at two different speeds. The high pressure distribution was produced in the vicinity of the boundary point of two worms due to the difference in the longitudinal velocity of worms. The deliquoring increased markedly while the rotation ratio increased. The expression performance was evaluated based on the theory of batchweise operation.
3) The relation between cake thickness and filtrate volume, which serves as a basis of the determination of average void ratio and average filtration resistance, was obtained on the principle of the change in local hydraulic pressure of filter cake. On the basis of the filtration data obtained under variable pressure conditions, local porosity and local specific filtration resistance were determined approximately.
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