Grain Cleaner - Important Grain Cleaning Equipment

A grain cleaner is a machine that is designed for finer cleaning and sorting of all types of grains and seeds. It removes dirt and other impurities, such as stones, chaff, foreign seeds, stick, buck, leaves and sand. The grain cleaning machinery are used to clean a variety of crops including wheat, rice, maize, cereals, nuts, pulses and spices. A grain cleaning equipment can primarily removes three types of materials:

* Fine particles, which pass through a particular screen size.
* Bulky and large material, which remains atop a screen that lets the grain to pass.
* Light and low density material, such as lighter kernels.

The grain cleaner gives a fresh and clean look to the grains by blowing away all the impurities. These grains are then further processed by other machines before consumption.

The cleaning tools are generally made of stainless steel or other robust metals. Some of the components of a cleaning machine are feeding valve or hopper, cleaning chamber, screens and suction system.

The machine operates on the basis of differences in the thickness, width and length of the grains, their aerodynamic properties, shape, specific weight and surface condition. Let us now understand the working of a grain cleaner. The grains are fed inside the cleaning chamber by the feeder roller. Then they are transferred from cleaning chamber to the screen. The suction system of the cleaner lifts the lighter impurities from the grains. The extracted impurities are deposited in a separate chamber. The grains are then cleaned by the screen with the help of the rubber ball system. The rubber ball system also helps to keep the perforation of the screen open. After being passed through the screens clean grains are again passed through air sifter and aspiration. The remaining light contaminants are sucked off by an upward draught of air. The clean grains are then collected in a different collecting chamber.

The cleaning devices are very economical and easy to maintain. The initial cost of investment of a grain cleaner is also very low. However, no cleaning tool is able to remove all the impurities. Therefore, the measure of the cleaner performance of a cleaning machine depends on its efficiency. However, the efficiency of a the machine is not constant. As long as grains are cleaned to meet some contract specification or Grade, efficiencies less than 100% are acceptable.

Efficiency, %= (Amount of material actually removed /Amount of material that could be removed) *100

These cleaning equipments are either stationary or mobile. Different types of machines available are:

* Screener-scalper cleaners
* Vibratory
* Rotary
* Gravity
* Drag-Scalpers
* Aspiration cleaners