Multiple screws

An oil-free compressor—typically a rotary screw, multiple-stage design... 

Articles of circular cross section may be made in iron paste molds. To keep the inner surface of the paste mold moist, it is coated with shellac or varnish and a mixture of charcoal and linseed oil is baked on. Hot iron molds ate used for ware of any shape, particularly for screw threading, multiple decoration, or raised lettering. 

Dried product is collected in either cyclones or baghouses depending upon the product-particle size. When primary coUection is carried out in cyclones, secondary collection in a baghouse or scrubber is usually necessary in order to comply with environmental regulations. A rotary valve is used to provide an airlock at the discharge point. Screws are utihzed to combine product from multiple cyclones or large bag-houses. If required, a portion of the dried product is separated from the main stream and returned to the feed system for use as backmix. 

Flinn et al. [30] describes an experimental impact technique in which <100)-oriented LiF single crystals ( 8 ppm Mg) are loaded in a controlled manner and the multiplication of screw dislocations is measured. The peak shear stress in this relatively soft material is 0.01 GPa. For shear impulses exceeding approximately 40 dyne s/cm, dislocation multiplication is adequately described by the multiple-cross-glide mechanism [(7.24)] with m = l/bL = (2-4) X 10 m, in reasonable agreement with quasi-static measurement [2]. 

In the intermittent processes, single or multiple parisons are extruded using a reciprocating screw or ram accumulator. In the former system the screw moves forward to extrude the parisons and then screws back to prepare the charge of molten plastic for the next shot. In the other system the screw extruder supplies a constant output to an accumulator. A ram then pushes melt from the accumulator to produce a parison as required. 

Continuous production ol charcoal is typically performed in multiple hearth furnaces, as illustrated in the Herreshoff patent shown in Figure 2. Raw material is carried by a screw conveyor to the uppermost of a series of hearths, /kir is supplied counter-currently and burns some of the wood to supply process heat. As the layers of wood carbonize, they are transported to the lower (hotter) hearths by rakes. The hot charcoal product is discharged onto a conveyor belt and cooled with a water spray. 

Screw pumps are available in single or double-rotor (multiple) types. 

The simplest molds consist of two parts one fixed and one moveable. We use such molds to fabricate items, such as disposable stadium cups, compact disks, and coat hangers, which have simple designs with no undercuts. As the complexity of the product increases, so must the complexity of the mold. The molds used to produce large items, such as dishwasher tubs and automobile bumpers, may consist of multiple moveable components and weigh several tons. Even apparently simple items, such as screw tops for bottles, require a complex ejection system that unscrews the product from part of the mold. In order to facilitate cooling, virtually all molds are designed with liquid cooling channels. 

Cross-gliding of screw dislocations has an important effect on the overall plastic deformations of crystals because it is the primary cause of both multiplication, and strain-hardening as discussed above. 

Multiple reactor processes, 20 170 Multiple screw pumps, 21 73 Multiple spinnerette per bank process,... 

The biomass is fed overbed through multiple feed chutes using air jets to help distribute the fuel over the surface of the bed. Variable-speed screw conveyors are usually used to meter the fuel feed rate and control steam output. Feedstocks such as bark and waste wood are chipped to a top size of 25 mm (1 in) to ensure complete combustion. The bed usually consists of sand around 1 m (3 ft) deep. This serves to retain the fuel in the furnace, extending its in-furnace residence time and increasing combustion efficiency. It also provides a heat sink to help maintain bed temperature during periods of fluctuating fuel moisture content. 

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