Screw Conveyors
Screw conveyors are one of the oldest conveying methods known to man and still the ideal method for many applications. Though screw conveyors and augers are technically synonymous (any conveyance method driven by rotating threads) the processing industry typically reserves the term “screw conveyor” for larger executions, and augers for enclosed, tubular conveyors. For precise metering using screws, see screw feeders.
ABM supplies screw conveyors for a huge array of products as long as they’re not too abrasive, fragile, stringy, or are solid and sticky. They’re highly popular in chemical, meat, agriculture (excluding produce), plastics, waste, and many other industries. Their simple & rugged design makes them cost-effective, versatile, and able to accommodate numerous inlets and outlets or act as a live-bottom to a bin.
High-grade and polished surfaces can be used to reduce it, but friction is inherent in screw conveyor design. For this reason they’re not to be used with delicate or extremely abrasive materials like aggregates, which will eat through metal over time.
Design Options
Open Trough
Open troughs are ideal for bulk applications where product needs to be fed over a large area and conveyed to a single point. Examples include front loaders dumping grain into the beginning of a process, live bottom bins for large vessels, etc.
Closed Trough
Closed troughs are necessary for many application whether it be to keep environmental elements from getting in, product from getting out, or to meet hazard or sanitary specifications. And of course, closed trough means the product can be conveyed up steep slopes or vertically.
Shafted
Shafted screw conveyors are more reliable up steep slopes for many applications and are much sturdier. They can go greater lengths, can convey tougher product, and because they’re not constantly rubbing on the liner or bin of the conveyor, they require less maintenance.
Shaftless
Shaftless screw conveyors are especially effective with uneven, clumpy, and sticky material. This advantage with such product remains for vertical runs because they don’t need a bottom shaft. And because they don’t have a core, their capacity is increased and they can go about corners.
Similar products
Augers: Generally the term “auger” is reserved for lower-throughput, enclosed designs.
Screw Feeders: Screw feeders, or meter screws, are screw conveyors meant to convey precisely. This will include extra sensors and special drives & screws.
Advantages
Compatible with any product flow, horizontal to vertical
Wide range of products, from powders to liquids
Can be made vapor-tight for hazardous products in chemical industries
Can easily have multiple controlled discharges
Can be integrated into storage to create live-bottom bins
Drawbacks
Can destroy delicate product
Can be destroyed by tough product
Not great for stringy material
Inflexible & not modular