Design and construction of an electric powered tomato slice dryer.

Abstract

Uganda’s economy is largely agro-based and with the developing technology has to meet the needs of the farmers. Uganda has merged to be a fruit surplus area and tomatoes are among the most important fruits grown annually around the world and most of them are consumed as processed tomatoes such as tomato paste, tomato sauce, tomato powdered and ketchup. In Uganda, the local processors still dry their tomatoes by sun energy. This method is unreliable since it depends on sun intensity which is highly affected by weather changes. Some tomato dryers do exist but they have very high initial costs and non-uniform drying rate. However, there is a need of tomato dryer that can be cheaply obtained, one that is not affected by weather changes, can increase the shelf life of tomatoes and ensure uniform drying rate. Therefore, the objective of this study was to design and construct an electric powered tomato slice dryer which helps people to dry tomatoes to low moisture content without being affected by weather hence increasing their shelf life. Design and construction of the various components of the electric powered tomato dryer was carried out by analyzing forces acting on them so that components don’t fail during operation. Force analysis led to selection of proper materials to withstand the forces to avoid failure. Engineering drawings of the various components of the dryer were drawn before the various components were constructed. Then machine assembly was done according to the engineering drawings and the performance of the machine was tested. In summary, the prototype development of an electric powered tomato dryer, provided a great remedy to the challenges faced during drying processes of tomatoes in Uganda. The tomatoes were dried to a low moisture content (30%) which enabled them to be stored longer than the refrigeration method. Also tomatoes were able to be dried in one day compared to the sun drying methods which takes more than two days. Hence the dryer encouraged preservation of tomatoes in a dry state for a longer period of time.