Discharging screw

An important variation of this filter is based on replacing the rigid outer waU necessary for containing the feed and the cake on the rotating table by an endless mbber belt. The belt is held under tension and rotates with the table. It is in contact with the table rim except for the sector where the discharge screw is positioned, and where the belt is deflected away from the table to aUow the soHds to be pushed off the table. The cloth can also be washed in this section by high pressure water sprays. This filter, recendy developed in Belgium, is avaUable in sizes up to 250 m, operated at speeds of 2 minutes per revolution, and cake thicknesses up to 200 mm. 

Screw-Discharge Batch Mixers A variant of the sigma-blade mixer is now available with an extrusion-discharge screw located in the saddle section. During the mixing cycle the screw moves the material within the reach of the mixing olades, thereby accelerating the... 

A twin screw feeder unit is used to dose dry blend into the compounder. A discharge screw feeds the melt into a pelletiser unit, which is a multi-hole die plate through which the melt is forced into strands, cut by rotating knives and cooled. Details are available of a range of extruders developed for PVC compounds (34). 

DUST COLLECTOR -WITH DISCHARGE SCREW AND ROTARY AIRLOCK... 

Screw-Discharge Batch Mixers A variant of the sigma-blade mixer has an extrusion-discharge screw located at the center of the... 

Ash Removal System. A rake, screw conveyor and ash box comprise the ash removal system. A rake mounted above the pinhole grate ploughs ash towards the centrally mounted ash discharge screw. A screw conveyor transports the ash via a gate equipped chute into the ash bin below. 

A discharge screw conveyor is located at the bottom of the tapered hopper and transports the treated material out of the trailer into a sealed collection drum. The primary chamber top is constructed such that the gas flow within the chamber can be either counter-current or co-current. Infrared energy is supplied by heating elements which are transversely mounted across, and equally spaced along, the length of the chamber. The elements are silicon carbide rods and are connected in wireways external to the chamber. The connections are accessed by... 

FIGURE 39.27 Flow diagram of a steam dryer for pulp (A, wet pulp B, heating steam at 6-15 bar C, dried pulp D, generated steam at 2-5 bar E, condensate F, plug feeder, G, fluffer H, discharge screw 1, circulation fans J, cooling-air fan). (Courtesy of MoDo-Chemetics.)... 

In contrast to the emphasis placed upon the enhancement of storage capacity with bin discharge screws, feeders designed for controlled-rate dispensing have the prime objective of securing reliable, predictable, and controllable solids flow. Two conditions have to be satisfied first, to ensure the flow channel is smooth and continuous in all conditions of operation second, that the volume of the feed screws fills in a consistent manner with loose solids in as uniform a state of density as possible. In general, a mass flow channel best serves both objectives, due to its performance reliability and because the total flow channel passes all the... 

Bin discharge screws are intended to work in flooded conditions. Starting loads and extraction pattern are related, in that pressures developed at the screw interface, and the pattern of extraction imposed at this region, depend upon the design of the hopper section of the bin and how it operates. The selection of screw size, its form and geometry, and the hopper/screw interface design are interdependent within the overall bin design, for both cost and performance. 

The hopper shape of the feeder and the form of the extracting screw did not provide and sustain mass flow, to allow fresh make-up material to stabilize in condition before reaching the discharge screw region. 

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