Development and testing of a rotary type black pepper cleaner

Abstract

A power operated rotary type black pepper cleaner is developed, tested and its performance evaluated. The major parts are an inclined circular disc, an involute shaped scraper, a feeding unit and a collecting tray.

The black pepper admixture is fed to the drum sieve through a hopper. By rotating the sieve, feed material fall uniformly over one-half of the area of the inclined rotating disc. Good pepper grains being nearly spherical in shape roll down at one end, whereas foreign materials which cannot roll down as freely, is scraped out at the other end by means of an involute scraper. Both cleaned and uncleaned grains are received in a collecting tray placed below the disc. A 3-phase 0.5 HP variable speed dynodrive motor along with a 10:1 gear reduction unit operates the machine.

The important physical properties of black pepper relevant to cleaning process are also studied. The trials are repeated for the surfaces of mica and cotton under different levels of feed rate, angle of inclination and speed. Better performance is obtained in the case of cotton surface. Under these conditions, a cleaning efficiency of 88 per cent is obtained at a feed rate of 12 kg/h, angle of disc 11o and at a speed of 10 rpm. The cost of the machine excluding the power unit comes to Rs. 1’100/-. The operating cost of machine is found to be Rs. 16.45/h. It is recommended for further studies and modifications.