Doubling Down on Direction: Thayer Scale Differential Feed Screws Provide Reliable Material Delivery

Doubling Down on Direction: Thayer Scale Differential Feed Screws Provide Reliable Material Delivery
Thayer Scale has over seventy years of experience designing and manufacturing continuous weighing and feeding equipment for the dry solids conveying and processing industries.

The company understands the requirements of material handling applications and screw feeders designed to meter bulk materials at a controlled feed rate. Thayer Scale’s innovative, proprietary compound flight feed screw features a forward-feed helix and a reverse-feed helix concentrically mounted to the same shaft. This innovative, bi-directional design provides reliable material delivery at low flow rates without the complexity of a twin screw.

Single feed screws often trigger an array of manufacturing problems, which the Thayer Scale differential compound flight feed screws resolve. Small capacity feed screws cannot achieve a uniform and reliable filling, and large capacity feed screws create significant material discharge pulsation during low feed rates. The right fit is essential. Small feed screws installed in a feeder designed for a large feed screw can trigger material buildup and blockage, and prevent comprehensive feeder cleaning. Additionally, both single and twin small diameter feed screws are fragile and unreliable in heavy industrial process applications.

Thayer Scale’s differential feed screws resolve these challenges. The large pitch of the screw’s outer winding ensures reliable and complete filling of screw flights. The screw’s differential feeding action provides consistent, precise, and reliable feeding of material without pulsation. The solid flight screw offers robust over-wind, ensuring reliable performance and long-term durability in harsh process environments. In addition, a low-rate, differential feed screw can be installed in a feeder designed for large augers, and high feed rates significantly increasing the effective turn-down of the feeder. This can be particularly helpful for custom-compounders who need maximum flexibility and fast change-over.

Benefits of the differential feed screw design:

  • A large diameter to prevent “boring” through products, or products bridging over the screw’s perimeter
  • Differential action between flights to produce low flow rates with a high screw RPM
  • Uniform and pulse-free feeder discharge
  • Multiple screws with common diameters to eliminate feed tube changes and resulting in dead zones
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Thayer Scale is a leading global manufacturer of equipment for the continuous weighing industry. Founded in 1949, we provide engineered solutions for the food, energy and ...

Thayer Scale