Dewatering, mechanical

Some horizontal belt vacuum filter designs incorporate a final compression stage for maximum mechanical dewatering. This is achieved by another compression belt which presses down on the cake formed in the preceding conventional filtration stage. 

The design of the mechanical dewatering press is such that there is an upper limit to the pressure to which the lignite is subjected. 

Eventually, the latexes are dewatered and recovered in solid form by freeze-coagulation and centrifugation, or by mechanical isolation. Mechanical isolation consists of shear coagulation of the latex to form a paste. The paste is then heated and sheared to form a crumb. Finally, the crumb is mechanically dewatered and ground to the desired particle size. A key feature of this method is the relatively low energy consumption of this process (17). 

Other by-products of the brewing process are malt sprouts, brewers condensed solubles (produced from the mechanical dewatering of brewers grains) and brewers yeast. Most of the brewers grains are marketed in the wet form... 

Vacuum filtration and screen-bowl centrifuges are the principal unit operations used for mechanical dewatering of fine coal. Pressure filtration (plate and frame filter presses and continuous belt filter presses) is used to a much lesser extent to dewater fine... 

Whenever it is necessary to remove moisture from virgin or waste biomass feedstocks, air drying, mechanical dewatering, and drying with waste heat or stack gases should be evaluated first. The lower costs of these methods compared to the costs of thermal drying in which external fuel or a portion of the feedstock supplies heat may justify their use. 

Turn, S. Q., Kinoshita, C. M. Ishimura, D. M. (1997), Removal of Inorganic Constituents of Biomass Feedstocks by Mechanical Dewatering and Leaching. Biomass Bioenergy, 12(4), 241. 

Asbestos cement is regarded as an application rather than a cement type. The aqueous slurry of cement and asbestos is mechanically dewatered and sets to a very rugged material, from which pipes, containers, roofing-tiles etc. can be manufactured (Eternit , Fulgurit ). For further information see Section 5.2.2.3. 

It is more efficient to mechanically dewater solids than thermally, due... 

If the mechanism of densification is considered (refer to the sketches in the upper part of Fig. 8.1), it becomes clear that the pores in the feed for a pressure agglomeration process of any kind must not be filled completely (saturated) with a liquid. An example of such a material would be a normal filter cake, i.e. one that has not been blown dry or otherwise further dewatered. Since liquids are incompressible, the pressing force would increase quickly and mechanical dewatering would have to occur, which further reduces the speed of densification. It would also require an effective separation of solids and liquid during the densification process this is a task which, so far, has not been solved satisfactorily. Therefore, with increasing pressure applied to the particulate solids, which typically results in higher densification or lower porosity, the moisture content of the feed must diminish. In high-pressure a lomeration the feed must be essentially dry ... 

Currently, dewatering in sludge beds and lagoons is considered to be too long and difficult to control. Therefore, instead of these beds, mechanical dewatering technology is employed. In this case the following systems are used ... 

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