DESIGN OF WATER MILLS FOR MULTIPURPOSE APPLICATIONS

Abstract

In remote area demand of electricity has become a priority, especially for lighting rather than luxury. Similarly mechanical power is needed for the normal tasks such as milling and expelling etc to improve the productivity. Consequently, more appropriate and modern energy system is needed to meet this ever-increasing demand in remote under developed hilly area lower capacity under micro hydro generally referred as Pico hydropower having plant capacity upto 5 kW is considered to be an appropriate resources for meeting the energy needs for people. In hills, water mills known as gharats are having used for grinding cereal (grains) since ancient time which may be considered under this range. Thousand of water mill sites exist in Himalayan and Sub-Himalayan ranges. At most of these site vertical shaft water mills having very low efficiency are still in used, Lot of work has been done for the improvement of this water mills in the past, however a little work has been reported to use these water mills for multipurpose applications The problem associated with these water mills is their low speed (about 100-200 rpm). In order to generate small amount of electricity at these sites, speed increasing system to increase speed from 100 to 1500 rpm is needed. It will not be practically possible to achieve this by simple belt driving system as this vertical shaft system are not provides any bearing and are supported by weight of stone acting axially.