No abstract

The reverse force on the returning blade of a water turbine can be reduced by setting a deflector on the returning blade side of a rotor. The deflector configuration can also concentrate the flow which passes through the rotor so that the torque and the power of turbine can be considerably increased. The placing of Savonius in Darrieus rotor is carried out by setting the Savonius bucket in Darrieus rotor at the same axis. The combination of these rotors is also called a Darrieus-Savonius turbine. This rotor can improve torque of turbine. Experiments are conducted in an irrigation canal to find the performance characteristics of presence of deflector and Savonius rotor in Darrieus-Savonius turbine. Results conclude that the single deflector plate placed on returning blade side increases the torque and power coefficient. The presence of Savonius rotor increases the torque at a lower speed, but the power coefficient decreases. The torque and power coefficient characteristics depend on the aspect ratio of Savonius rotor.

The objective of this study is to blend the South Sumatera low rank coal and palm shell charcoal for producing bio-coal briquettes which have better fuel properties. The experimental study for making biocoal briquettes was carried out to examine the effect of raw material composition and binder type on the quality of the briquettes produced. A screw conveyor machine equipped with a three blade stirred and designed with the length of 40 cm, mixing process diameter of 10 cm and the capacity of 2 kg bio-coal briquettes per hour was used to produce bio-coal briquettes ready to use in small industries. Proxymate analyses of the South Sumatera low rank coal, palm shell charcoals and bio-coal briquettes were conducted in accordance with the American Society of Testings and Materials (ASTM) standards and the calorific value was determined by using a Bomb calorimeter. The experimental results showed that the calorific value of bio-coal briquette was greatly influenced by the raw material composition and the binder type. The highest calorific value was 6438 (cal/g) at the sampel of SSC65-PSC20-B15(2).

A review of waterwheel history has conducted to evaluate the possibility and thetechnology development in its relation to harvest the energy from the flowing water inand out of irrigation canal regarding the tidal movement. The study has conducted atthe east shore of South Sumatra. Hydro energy became a promising renewable energyin order to achieve at least 5% of total Indonesian national energy mix consumption in 2025. Tidal turbine energy is technologically potential for Indonesian futureregarding the beach of 81,000 kilometers long and 20 millions hectares of tidalswamp area out of 33 millions hectares available. Mechanical torque of 30 Nm isproduced by a waterwheel of 0.38 meter radius. An estimation of 60 watt at the peakof rain season could harvested from each tidal irrigation canal in Telang II. Thismechanical energy is applicable to generate small quantity water pump, water aerationinjector and small electric energy energy appliances.

South Sumatera is one of the provinces in Indonesia that has the largest coal reserve in Indonesia. Unfortunately, the type of coal is mostly in the low-rank coal. Through a national energy policy, the government of the Republic of Indonesia has set an increased consumption of coal for domestic use. The energy derived from coal will be increased approximately 33 percent of the total Indonesia energy consumption in 2025. Currently, approximately 70 percent of Indonesia's coal production is used by the State Electricity Company as fuel for power generation, 10 percent for the manufacturer of cement, and the rest for industrial and metallurgical processes. The low-rank coal, which contents a high moisture into solution be decreased firstly and then through drying process before using in industry. In the power generation industry, usually, low-rank coal is dried naturally in a closed stockpile before being used as fuel, and spontaneous ignition happens frequently. The results show a decrease in moisture content for solar drying and using laboratory scale oven. Solar drying depends on the solar radiation falling onto the surface, so coal drying depends on highly weather and time.