Development of batch type multiplier onion ( Onion Aggregatum) peeler with centrifugal discharge

Abstract

Multiplier onion (Onion aggrega tum) is consumed in large quantity in southern provinces of India. These are used in large quantities in the catering and pickling industries, creating a need for peeling equip ment. Multiplier onion peeling is an essential step in producing many of the onion products such as dehy drated onions, onion powder, onion flavoring, onion salt, onion rings, and pickled and canned onions, which is a very tedious process. A batch type peeling machine suit able for farm-level operation was designed and tested for multiplier onion. The equipment consisted of a cast aluminum drum seated over a rotating disc. Inner surface of the drum and top surface of the lower disc are covered with corrugated rubber sheet which aids in the peel ing process. The multiplier onion needs to have the ends cut with a sharp knife and soaked in clean water for a period of 10 min to as sist the loosening of peel followed by air drying for 1-2 min to remove the surface water. Major operational parameters: speed of operation and abrasive surface on the drum were optimized for peeling efficiency, damage to the bulb and other performance parameters. The capacity of the peeler was about 50-60 kg/h. The peeling efficiency was about 92 percent with unpeeled and damaged percentage being 6 and 2 percent, respectively. The cost economics study revealed that the equipment had a saving in labour and cost to a tune of about 68 and 69 percent, respectively, with a payback period of 1.40 years. The equipment can be adopted by small and medium multiplier onion processing industries.