Screw action

In the extraction of citms juices it is desirable to have as gende an extraction pressure as possible. There should be minimal contact time between juice and pulp to reduce the amount of bitter substances expressed from the peel into the juice. The amount of suspended soHds in citms juice is controlled in a subsequent separation in a finisher. A screw action is used to force the juice through a perforated screen and separate the larger pulp particles from the juice. The oil level in the juice is adjusted by vaporizing under a vacuum (10). The separated pulp is washed and finished several times to produce a solution which is then either added back to the juice to increase juice yield, or concentrated to produce pulp wash soHds, also called water extract of orange soHds, which can be used as a cloudy beverage base. 

Wet low-shear granulator subclasses primarily are distinguished by the geometry and design of the shear inducing components shear can be induced by rotating impeller, reciprocal kneading action, or convection screw action. 

A new option for micromolders is an injection machine that replaces the traditional screw with a motor-driven plunger. Named for the part sizes it produces, the Sesame is a small electropneumatic micromolding machine made by Hull Corp. (Warminster, PA). The machine can mold 20 thermoplastic sesame seeds from a single pellet. Instead of a screwing action, the Sesame uses a tiny plunger to push material into the mold. This plunger, that can be as small as 1.5 mm in diameter, is... 

FIGURE 13.22 ( a) Schematic of an extruder for ceramics, (b) Detail of the screw action on the ceramic mix. (c) Velocity due to drag and pressure with the net flow. Ideas for this composite figure were taken from Mutsuddy [62]. 

Ion exchanger, exposed to gravity, moves down and is transferred to the bottom of tanks 5 and 6 via screw action. The solution, moved at a constant rate, is transferred to tank 5 with a hose pump. After filling tank... 

Feed to the rotary table is usually across a weir positioned over the full width of the segment. The filter medium is a single piece of material, in an annular shape, and the segments are divided underneath the medium, with appropriate filtrate discharge pipes. The action of the screw conveyor in removing the cake leaves a thin heel of unremoved solids (or the medium would be rapidly abraded by the screw action). If this heel would be a problem, than compressed air is injected from below the medium, just under the feed point, to free the heel and mix it with the feed slurry. 

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