Executive Summary : | Storage and transportation of food products is very critical for effective use of agricultural produce. Perishable food products such as milk, vegetables and fruits have limited shelf life and require refrigeration for storage and transportation which may not be accessible at many places especially in rural areas. According to UN reports, one-third of food produced is wasted globally. Some of the wastage can be reduced if the shelf life of products is improved by converting them into powders without losing nutritional content. Fruits and vegetable such as tomatoes, mangoes, and oranges, etc. can be converted into powders through the spray drying process. In the spray drying process, food products are converted into aqueous solutions and passed through atomizers to convert them into sprays - this increases the surface-to-volume ratio of the liquid and the water content is then removed through a drying process. Increasing the dry matter content in the liquid feed to the atomizer will reduce the drying time and energy requirement significantly. However, increasing the dry matter will increase viscosity of the liquid and result in poor atomization characteristics which in turn will affect the quality of the powder produced.
This project is aimed at developing an atomizer for high viscosity liquids used in applications such as food processing. Such an atomizer will be a primary requirement for in developing an energy efficient spray drying system. Compact and energy efficient spray drying system is essential for converting the agricultural produce to powder at the source there by reduces the wastage. Reducing the drying time and energy consumption through the development of an atomizer which can atomize viscous liquid feed effectively is a critical part in of such a system. Hence, in this project, we propose to design, develop and evaluate an air-assisted atomizer which can atomize high viscosity liquids with a low amount of atomizing gas requirement. The main components of the project includes designing of an experimental setup including gas and liquid supply systems, atomizer and optical diagnostics setup, testing the proposed atomizer at different operating conditions and evaluating its suitability to the spray drying applications, coming up with alternative atomizer designs and evaluating the designed atomizer under realistic conditions. |