DEVELOPMENT AND PERFORMANCE STUDY OF A CABINET DRYER
Date
2012-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
HAJEE MOHAMMOD DANESH SCIENCE AND TECHNOLOGY UNIVERSITY, DINAJPUR
Abstract
Moisture content is an important factor in the preservation of grains. If the moisture
content is above the safe moisture level at suitable temperature, the grains are in the risk
to be attacked by different types of insects and microorganisms and loss of value due to
spoilage. Due to the lacking of drying facilities, a huge amount of produced grains are
lost every year in Bangladesh particularly in the rainy season. Keeping the problem in
mind a cabinet dryer was developed in the Power and Machinery Laboratory, Faculty of
Agro-Industrial and Food Process Engineering, Hajee Mohammad Danesh Science and
Technology University, Dinajpur. The dimensions of the dryer are 1.52m long, 0.61m
wide and 1.52m high. An automatic temperature control system was incorporated in the
existing dryer by using thermocouple, temperature controller and magnetic contractor to
control the quality of the grain. This system maintains the safe drying temperature level
for grain. There are four trays placed one over other inside the dryer. The grain holding
capacity of each tray is 10kg of fresh paddy. About 40kg paddy was dried per batch at the
temperature 43-44°C in seven hours period from the initial moisture content of 25.2% to
final moisture content of 13.6% (wb). The electricity cost for drying per kilogram of
paddy was Taka 3.74.
Description
Agricultural processing may be defined as an activity which is performed to maintain or
improve the quality or to change the form or characteristics of an agricultural product.
The main purpose of agricultural processing is to minimize the qualitative and
quantitative deterioration of the material after harvest (Sahay and Singh, 2001).
Drying, as part of agricultural processing, is the removal of moisture to safe moisture
content by the application of heat. Drying is practiced to maintain the quality of
grain during storage to prevent the growth of bacteria and fungi and the
development of insects and mites. The safe moisture content for cereal grains is
usually 12 to 14% on wet basis (Bala, 1997).
Keywords
A CABINET DRYER, Hot air supply system, Moist air outlet