Material Handling: Screw Conveyor Goes Mobile, Adds Trough Hopper
Two new models of flexible screw conveyors are available from Flexicon Corp., Bethlehem, Pa. First, a mobile, sanitary version can be tilted down and rolled to serve multiple functions. Using a manual jack screw, the support boom and conveyor can be raised for discharging into vessels or other process equipment. Fully lowered, it can be rolled through doorways as low as 7 ft and aisles as narrow as 42 in.
Sanitary features include a caster-mounted frame, support boom, and hopper grate of 316 stainless steel; sanitary quick-release cleanout cap; quick-disconnect discharge-box access cover; stainless control panel with stainless conduit and liquid-tight compression fittings, allowing washdown during changeovers and/or conveying of corrosive materials.
Second is a screw conveyor with a trough hopper. It can receive materials from multiple outlets of feeders, grinders, blenders, and other process equipment. The hopper has an extended charging adapter that exposes 45 in. of the flexible screw rotating within an inclined, U-shaped trough to charge material entering the hopper at any point.
The hopper has a stainless-steel grate for worker safety, and to prevent oversized particles from entering the conveyor. Smooth, crevice-free surfaces of the screw and tube interior allow in-place flushing with water, steam, or cleaning solutions through a lower cleanout cap and/or upper discharge housing. The flexible screw can also be removed for separate sanitizing and inspection of the polymer conveyor tube and stainless-steel hopper, as well as the screw.
Is one type of resin dryer faster or more energy-efficient than another? That question prompts competing claims from suppliers—but very little concrete data. When one vendor performed controlled tests to get some answers, its results, published here for the first time, prompted further debate about the difficulties of making valid comparisons and the many complex issues involved in dryer selection.
Processors today face bewildering choices of at least five basic types of dryers, whose capabilities are subject to conflicting claims from equipment suppliers. For the buyer, the most basic questions are: How much drying is needed for the job and which dryer types are up to the task?
Know what's new in paddle switches or weight-and-cable sensors? What about capacitance, vibratory, and ultrasonic level gauges? Are radar or laser systems worth the money? It's time to get educated: Having the right tools for materials management is more important than ever.