Special screw feeders

Ajax Equipment Ltd. (1998) Lynflow Slot Enhancing Technique for Uniform Pitch Screw Feeders. www.ajax.co.uk. 

(October 2005) The static screw elevator. Proceedings of the 8th International Conference on Bulk Materials Storage, Handling and Transportation, University of WoUangong. 

Forcade, M.P. (1994) Screw Conxeyor 101, Basic Training Manual for Screw Conveyors. Goodman Conveyor Company. 

(1994) Guide to the Specification of Bulk Solids for Storage and Handling Applications. Bulk Materials Handling Committee. 

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A batch-type reactor equipped with a screw feeder and mixer is offered by US patent [49]. A special grate is mounted inside the reactor, above the cracked melted waste plastics mixture. Scraped waste plastics which are submitted to the cracking reactor melt at the grate and fall down to the reaction mixture. As in the case of previous patent description, in the course of cracking process a mixer of a special construction scrapes coke form the reactor walls and then coke is removed from the specially shaped reactor bottom by a screw transporter. The process temperature attains level of 450° C. 

An alternative method to slurry feeding has been proposed for PBX. The new scheme uses an agitated hopper and screw feeder to move water-wet PBX to a feed line with air or other conveying medium. The feeder would be specially designed for use with PBX material. The advantages for this feeding scheme are ... 

The fuel solids are fed into the fluidized bed by means of a screw conveyor with a specially designed feeder valve. The feed port is located 5 inches above the gas distribution plate. The 2 -inch screw is constructed of carbon steel with a Type 310 stainless steel coating on the wearing surfaces. The construction details of this feeder and the auxiliary solid feed hopper system have been described by Burton and Bailie (2). The feeding unit has performed successfully in smoothly feeding 15-60 lbs of solids/hr into the fluidized bed. 

Screw elevator design entails considerably more expertise than that required for screw conveyors. The performance is more sensitive to the nature of the product handled, and a host of operating hazards, not relevant to screw conveyors, may be experienced. Screw feeders incur different, but similarly specialized, experience for optimum design exploitation. 

Related Calculations. Use this procedure for screw or spiral conveyors and feeders handling any material that will flow. The usual screw or spiral conveyor is suitable for conveying materials for distances up to about 200 ft (60 m), although special designs can be built for greater distances. Conveyors of this type can be sloped upward to angles of 35° with the horizontal. However, the capacity of the conveyor decreases as the angle of inclination is increased. Thus the reduction in capacity at a 10° inclination is 10 percent over the horizontal capacity at 35° the reduction is 78 percent. 

Conventional coal briquetting uses a thermoplastic binder and a well-plasticized feed. Referring again to Figure 403, vapors emanating from the blend are removed in a special horizontal screw conveyor (15) before the material enters the feeder of the roller press (16). 

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