Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

A study of vacuum and pressure expression dewatering

Conference ·
OSTI ID:6167749
The relative effectiveness of vacuum filtration vs. pressure expression for dewatering of fine coal and refuse was studied using a belt filter press. For clean coal, the change in moisture content was insignificant when vacuum dewatering was followed by pressure expression for relatively large size fractions (75 ..mu..m top size). Significant reduction in moisture content was observed in case of vacuum plus expression dewatering of refuse. Addition of coarse particles (such as large Plexiglas beads and coarse coal particles) showed major reduction in cake formation time and final moisture content. Attempts to measure the actual pressure exerted by the rollers as a function of applied hydraulic pressure showed that the pressure was evenly distributed over the belt width. Porosity was observed to be significantly reduced as shearing action of the belt filter press rearranges the cake particles. Effects of belt speed, hydraulic pressure and flocculant addition on cake moisture were investigated.
OSTI ID:
6167749
Report Number(s):
CONF-870323-
Country of Publication:
United States
Language:
English