Screw Conveyor Systems for Bulk Material Handling
Enclosed screw conveyors that move powdered and granular products without dust or spillage, engineered per project for horizontal, inclined or vertical duty.
Screw Conveyor
A screw conveyor moves powdered and granular materials through a fully enclosed trough or tube by means of a rotating helical flight. Kasas Teknoloji manufactures these systems mainly for food and packaging plants, engineering each unit around the product, the layout and the duty of the line it will serve. Because the casing is closed along the entire transfer path, dust escape, spillage and contamination from the surrounding air are eliminated. The same machine can be built for horizontal, inclined or vertical service, which keeps plant layouts compact and reduces the number of transfer points between process steps. Casings are produced in stainless or painted carbon steel, and product contact surfaces can be specified in food grade material. Capacity and conveying distance are determined per project.
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The working principle of a screw conveyor is direct. A geared motor turns a shaft carrying a continuous helical flight inside a U shaped trough or a closed tube. As the flight rotates, friction between the material and the casing wall prevents the load from simply spinning with the screw, so the bulk material is pushed forward along the axis toward the discharge spout. In horizontal duty the trough can run at a relatively high fill ratio. As the incline increases, part of the load falls back between the flights, so the fill ratio is reduced and the rotational speed is recalculated to compensate. Vertical auger conveyor arrangements use higher speed and a shorter pitch to keep the material column moving. Bulk density, particle size, moisture and abrasiveness of the product govern screw diameter, pitch, shaft section and casing wall thickness. Flexible screw designs run a spiral inside a bendable tube, which removes the need for a fixed straight route between the two points.
- Fully enclosed casing prevents dust emission and contamination along the entire conveying path.
- Horizontal, inclined or vertical configuration, engineered to fit the existing plant layout.
- Casings in 304 or 316 stainless steel with food grade product contact surfaces.
- Screw diameter and pitch selected according to bulk density and particle size of the product.
- Sealed inlet and outlet spouts give spill free transfer with no product loss under the line.
- Hinged covers and removable shaft connections shorten cleaning and maintenance downtime.
- Optional variable frequency drive lets the feed rate be matched to the downstream process.
- Flour, semolina and milled cereal transfer lines
- Grain silo filling and discharge in bulk material handling
- Dosing lines for sugar, spices and powdered additives
- Raw material feeding ahead of mixers in feed mills
- Controlled product feeding into packaging machines
- Plastic granulate and powdered chemical conveying
- Casing material
- 304 / 316 stainless or painted carbon steel
- Screw diameter
- Determined per project
- Configuration
- Horizontal, inclined or vertical
- Capacity
- Engineered to requirement
- Drive
- Geared motor, optional frequency inverter
- Product contact
- Food grade surface option
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Frequently Asked Questions
What is a screw conveyor?
A screw conveyor is a continuous conveying system that moves powdered and granular products inside a closed casing by means of a rotating helical flight. It is also known as an auger conveyor or a spiral conveyor. Because the casing is closed, the product never contacts the surrounding air, and no dust or spillage occurs along the transfer path.
How does a screw conveyor work?
A geared motor drives the shaft that carries the helical flight inside the trough. Friction against the casing wall stops the material from turning with the flight, so it is displaced along the axis toward the discharge spout instead. Throughput follows from rotational speed and flight pitch. With a frequency inverter, the feed rate can be tuned to the downstream process.
Which materials can a screw conveyor handle?
Free flowing powders and granular products such as flour, semolina, sugar, spices, grain, feed ingredients, plastic granulate and powdered chemicals are all suitable for bulk material handling with a screw. Bulk density, moisture, particle size and abrasiveness directly affect material selection and screw geometry. For sticky or caking products, the casing and flight design are adapted accordingly.
Should I choose a horizontal or a vertical screw conveyor?
The choice depends on the height difference between the two points and the space available. For transfers at the same level or on a shallow incline, a horizontal layout is more efficient because a higher fill ratio can be used. Where the lift is significant, a vertical or steeply inclined unit saves floor space but needs higher speed and shorter pitch to counter fall back.
How are screw diameter and rotational speed determined?
Diameter and speed are calculated together from the bulk density, particle size and moisture of the product plus the required throughput. As the incline angle rises, the fill ratio is reduced and the loss is compensated by speed. For abrasive products, wall thickness and material grade are increased. Final figures are set per project rather than taken from a standard table.
Is this system right for your plant?
Contact us for capacity, dimensions and integration; let us engineer your system.