Rural agricultural sector in developing countries such as Sri Lanka is still lacking efficient and cost effective devices for processing of agricultural produce. A dual heat dryer which utilises rice husk and solar energy for thermal energy generation required for the drying process was designed and developed at the Institute of Post Harvest Technology (IPHT), Sri Lanka for dehydration of agricultural produce. Performance evaluation of the dual heat dryer gave promising results for adoption by the farming community. The dryer is able to generate drying air temperatures ranging from 40 to 110°C thus, facilitating a variety of crop produce to be dried, such as drumsticks, bitter gourd, papaya, mango, lemon grass, mushroom and many more, with natural convection airflow. In most instances drying using solar energy alone is insufficient to accomplish the drying operation because the drying process has to be continued up to 10-15 hrs extending into the night. The incorporation of biomass energy into solar drying enables the drying process to be continued even in the absence of sun shine and thereby ensuring product quality. The benefit/cost ratio is 10:1 in the dryer and hence adoption by the farming community or in rural areas is extremely feasible. Furthermore, the renewable energy technology discussed in this paper would help to enhance the socioeconomic development of the rural community in developing countries like Sri Lanka.

One of the major solutions to reduce the consumption of wheat flour in the country is to introduce flour mixtures blended with rice flour and other locally produced grain flour to the market and flour based food processors, since it has a great demand even now. Blending equipment are essential to produce flour mixtures with uniformly distributed particles. Flour blending machines are available in the international market, but they are very expensive and those are not at an affordable price to purchase even for medium scale flour producers. Therefore, a low cost grain flour blender was designed and developed to introduce for flour producers. Developed grain flour blender was tested by blending rice flour with wheat flour to the ratio of 3:7 which is generally used for preparing bread. It was found that the minimum blending time required for giving a uniform mixture was 3 minutes when the equipment was operated at 51 rpm. Capacity of the blender was 50 kg per batch and it was operated by a 3 hp electric motor. When the developed flour blender is compared with the available blending machines in the international market with same capacity, it was found that the developed flour blender reduces the blending time and the initial cost of the machine is reduced by 5 times while the flour blending cost is reduced by 25%.