Continuous expression of slurry in a screw press

Journal Article · Tue Jan 01 04:00:00 EST 1985 · Int. Chem. Eng.; (United States)

OSTI ID:6504679

Shirato, M; Hayashi, N; Iwata, M; Murase, T; Ogawa, Y

An approximate method is described for predicting the steadystate performance of a screw press for the continuous expression of a slurry, with the worm channel being modified as the path between two flat plates. Screw expression of a slurry involves two mechanisms of dewatering which, for a batch operation, can be analyzed by the variable-pressure, variable-rate theory of filtration and by consolidation theory. By assuming that the expression consists of a succession of batch processes, basic equations are derived for the relationship between the dehydration rate, the feed rate, and the expression pressure distribution in a constant-pitch, straighttaper screw press. The thickness of the filter cake in the worm channel and the flow distribution in the consolidated cake are calculated for a given pressure distribution and feed rate, and the solids concentration and rate of discharge of the cake are estimated. The critical speed of rotation of the worm, at which the slurry becomes highly deliquored, is strongly influenced by the external diameter and helical angle of the worm. The theoretical results are in good agreement with experimental data for clay slurries with a concentration of 0.31-0.46 in the feed.

• Research Organization: Dept. of Chem. Eng., Nagoya Univ., Nagoya
• OSTI ID: 6504679
• Journal Information: Int. Chem. Eng.; (United States), Journal Name: Int. Chem. Eng.; (United States) Vol. 25:1; ISSN INCEA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
CLAYS
COMPRESSION
CONFIGURATION
DISPERSIONS
FILTRATION
FLUID MECHANICS
HELICAL CONFIGURATION
HYDRAULICS
MATHEMATICAL MODELS
MECHANICS
MIXTURES
PRESSES
REMOVAL
SEPARATION PROCESSES
SLURRIES
SUSPENSIONS
WATER REMOVAL