No abstract

Cashew nut farming in India is mostly carried out in small and marginal holdings. Energy consumption in the small scale cashew nut processing industry is very high and is mainly due to the high energy consumption of the drying process. The drying operation provides a lot of scope for energy saving and substitutions of other renewable energy sources. Renewable energy-based drying systems with loading capacity of 40 kg were proposed for application in small scale cashew nut processing industries. The main objective of this work is to perform economic feasibility of substituting solar, biomass and hybrid dryer in place of conventional steam drying for cashew drying. Four economic indicators were used to assess the feasibility of three renewable based drying technologies. The payback time was 1.58 yr. for solar, 1.32 for biomass and 1.99 for the hybrid drying system, whereas as the cost-benefit estimates were 5.23 for solar, 4.15 for biomass and 3.32 for the hybrid system. It was found that it is of paramount importance to develop solar biomass hybrid dryer for small scale processing industries.

No abstract

The provision of fresh water is becoming an increasingly important issue in many areas of the world. Clean water is a basic human necessity, and without water life will be impossible. The rapid international developments, the industrial growth, agriculture and population explosion all over the world have resulted in a large escalation of demand for fresh water. The solar still is the most economical way to accomplish this objective. The sun’s energy heats water to the point of evaporation. When water evaporates, water vapour rises leaving the impurities like salts, heavy metals and condensate on the underside of the glass cover. Solar distillation has low yield, but safe and pure supplies of water in remote areas. The attempts are made to increase the productivity of solar still by using nanofluids and also by black paint coat- ing inside the still basin. Heat transfer enhancement in solar still is one of the key issues of energy saving and compact designs. The essential initiative is to seek the solid particles having thermal conductivity of several hundred times higher than those of conventional fluids. Recently, as an innovative material, nanosized particles have been used in sus- pension in conventional solar still water. The fluids with nanosized solid particles suspended in them are called “nanofluids”. The suspended metallic or nonmetallic nanoparticles change the transport properties, heat transfer characteristics and evaporative properties of the base fluid, The aim of this paper is to analyze and compare the enhanced performance of a single basin solar still using nanofluids with the conventional water. They greatly improve the rate of evaporation and hence the increase in efficiency.

No abstract