Development of a natural convection dryer for use in developing countries

Miss Omolara Olufunso Adeyemo.Cn many occasions they separa- tely and jointly accompanied the author to temper the samples of corn used, load and off-load the dryer, both in the daytime hours and in the middle of the night as well.IV a reasonably satisfactory stage, and sophisticated dryers can be found dotted all over the countries.Attempts have been made by some of these countries to introduce these sophisti- cated dryers to farmers in developing countries but due to the high cost of installation, maintenance, operation and lack of technological knowledge and good management, their use has become uneconomical for such farmers.In order to reduce cost per farmer, and eliminate some of these limiting factors, some farmers in the developing countries have formed cooperative groups to obtain these sophisticated dryers, but difficulty in obtaining spare parts at appropriate times, again, has made this good venture uneconomical for the farmers.One can find broken down fans, dryers, generators, and damaged as well as rusty metal silos in the cooperative Agro-centres.The "Brook" dryer (Brook, 1964), which is basically a batch dryer, is simple enough to operate and to build on a farm, using available local building materials.The farmer and his family can construct these dryers themselves to avoid having to pay other workers.The dryer has a flue as a heat source and utilizes the buoyancy force of natural convection as a driving force to move heated air through the grain with- out any mechanical device.It is, therefore, intended to modify this simple and inexpensive natural convection dryer to give better drying performance for use in the developing countries.