A screw feeder is a device suitable for dealing with a variety of materials with great flowability characteristics. With a helicoidal surface attached to a rotating shaft inside a fixed tube, the screw feeder has a unique working principle, and that’s what makes it very efficient machine. The screw feeder has many advantages, but the biggest one is its design that has few different openings, each with its own size for unloading materials. Choosing the right screw feeder for a specific application plays a major role for producing high-quality final products. Read on to find out more about the unique working principle of the screw feeder.
The nominal flow is an important factor and it need to be calculated precisely before any screw feeder can be released on the market. It depends on many factors, including the rotation speed, inclination and the flowability characteristics of the material. There are many techniques for increased screw capacity, and the most efficient is called tapered diameter screw. But this technique is not recommended for every material, because the narrow back end will probably have arches over it. Another efficient method is using a variable pitch, which needs to be less than one-half of the the screw diameter.
The screw feeder works on the principle invented in the 3rd century B.C. known as the Archimedes’ Screw. The genius Archimedes discovered that a rotating auger fitted tightly within a cylinder is capable to elevate water efficiently. When the bottom of the screw feeder is submerged in water, the rotation of the screw lifts the lowest water level to the second tier, forcing new water to flow into the cylinder. With every rotation more water comes inside. However, not only for water, this working principle is also very efficient for all kinds of materials, such as stones, aggregates, concrete, etc.
In order to achieve positive results from this unique working principle, the operators need to choose the correct screw feeder and to install it correctly. The efficiency in every feeding application depends heavily on the chosen screw feeder, so choosing the right screw feeder is a key for successful operation.