Slurry discharge

The next step in the process is removal of remaining soluble and insoluble protein. Starch slurry discharging from the primary centrifugal separator must be diluted with process water to a slurry density of 10-12° Baume (18-21% dry solids). The starch may then be further purified in a second centrifugal separator to a final insoluble protein level of <0.38% dry basis (preferably 0.27-0.32% dry basis). However, since solubles content of the slurry must next be reduced by filtration of centrifugal decantation, the second step currently preferred is to utilize 8 to 14 stages of liquid cyclones which simultaneously remove residual gluten and wash the starch.207-209... 

Description PVC slurry discharged from reactors contains significant amounts of VCM (> 30,000 ppm) even after initial flashing. This... 

Double-octinq circulation 13 Slurry discharge pump... 

The dissolution of sodium silicofluoride in the solution tank of a dry feeder package unit can be accomplished by a jet mixer, but again a mechanical mixer is preferred. Because of the low solubility of sodium silicofluoride, particularly in cold-water applications, and the limited retention time available for dissolution, violent agitation is needed to prevent the slurry discharge. The preferred construction materials for a mechanical mixer are 316 stainless steel, plastic-coated steel, and Hastelloy-C (15). 

Normally, the product made in a crystallizer is for customer use and, therefore, the product size must be carefully monitored in order to stay within the prescribed limits. Typically, the product from a crystallizer will be sampled every l-2h during conditions when the operation is monitored to make adjustments in product size or characteristics. Ideally, the best place to sample the product is before it enters the slurry discharge pump and preferably from the slurry discharge line. 

The product classification in the elutriation leg is operated under flow rate control without automatic feedback from the product CSD. The rate of slurry discharge is set by the level control loop, responding to the differential pressure generated by the varying slurry-gas interface. A progressive cavity pump is the final control element to achieve the level control while providing minimal degradation of the crystals in the product slurry. 

If maximum product size is desired, the process stream flow is parallel, with a fresh feed and slurry discharge to product recovery equipment from each crystallizer. Cascaded product flow is avoided because flow through a series of tanks narrows the residence time distribution and the CSD and reduces the mass mean size by reducing the number of larger crystals in the distribution tail. This tail represents the major mass-weighted fraction. Population models have been solved to verify this effect, assuming an equal nucleation rate in each stage (Randolph and Larson 1988). The actual mean in industrial practice is lower because transfer of... 

The solids recirculation system offered in the Merco Centrifuge, for example, takes part of the slurry discharged through the nozzles back into... 

For the subsequent stages of the raw material preparation process — dewatering or partial dewatering of the slurry and burning it in the kiln — the up to 10% higher water content of the fine slurry discharged from the hydrocyclone... 

Mother liquor removed from the crystallizer is pumped under level control to the brine tank. Slurry discharged from the crystallizer is thickened to ca. 50 wt%. The liquor from the thickener is collected in the brine tank and pumped back to the leaching tank. The thickened slurry is redissolved in the Glauber s salt dissolving tank and pumped to a waste treatment system. 

A continuous stream of polymer slurry discharges through a heated zone for the first stage of pressure letdown in cyclone (b). For homopolymers, this connects directly to the secondary cyclone (d), bypassing the... 

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