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International Journal of Pure & Applied Bioscience (IJPAB)
Year : 2018, Volume : 6, Issue : 6
First page : (838) Last page : (852)
Article doi: :

Performance Enhancement of Pre-cleaner and Gravity Separator

Patil Pawankumar1*, T. K. Goswami2, Lad Priti3 and Pachpor Nitesh3

1,3Department of Process and Food Engineering,
College of Agricultural Engineering and Technology, Saralgaon, Thane, India
2Agricultural and Food Engineering Department (AgFE), Indian Institute of Technology (IIT) , Kharagpur, India
*Corresponding Author E-mail:
Received: 9.11.2018  |  Revised: 13.12.2018   |  Accepted: 19.12.2018



Cleaning and grading are the first and most important post harvest operations undertaken to remove foreign and undesirable materials from the threshed crops/grains and to separate the grains/products into various fractions.  The pre-cleaner cleaner is the basic machine in almost all seed processing plants. The air screen cleaner uses three cleaning principles viz aspiration, scalping, grading. A common air screen cleaner processing seed uses two air blasts and two screens. The first air system removes dust and light chaff before the seed reaches the first screen .The first screen allows the good seed to drop into the second screen.  The large foreign material rides over the first screen and is discarded. The second screen is a grading screen.The specific gravity separator makes the separation according to difference in density or specific gravity of the materials. This separator works on two principles,1) the characteristics of grains to flow down over an inclined surface, 2) the flotation of the particle due to upward movement of air. Mechanical cleaning with vibratory as well as rotary screen grain pre-cleaner is mostly adopted in grain markets nowadays, but these machines can give desired results if the important factors affecting, performance are selected, calibrated and operated. However, a rational approach to the design, selection and operation of the mechanical cleaning system does not exist. It is understood in a general that factors like the screen area, screen slope, feed rate and air velocity influence the cleaning efficiency and cleaned grain output per unit time of these systems. Screen effective surface area of 2.29 m2, screen slope of 6°, air velocity of 9.08 m/s and feed rate of 1.75 kg/s were optimum values of the independent variables for flat screen grain pre-cleaner. Air velocity of 2.4 m/s (70% flap opening), deck angle of 2.05° and deck oscillation of 500 rpm were optimum values of independent variables for gravity separator.

Key words:Cleaning, Grading, Screens, Pre-cleaner, Specific gravity separator, Screen slope, Screen area, Feed rate and Air velocity.

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Cite this article: Patil, P., Goswami, T. K., Priti, L. and Pachpor.  N., Performance Enhancement of Pre-cleaner and Gravity Separator, Int. J. Pure App. Biosci.6(6): 838-852 (2018). doi: