Prototype for Making Candles and Milk Pasteurization in El Salvador (Direct Use of Geothermal)

Abstract

With the support of LaGeo, it has been developed two prototypes of direct uses. The first is for making candles and the other is for milk pasteurization. 1. Prototype for making candles: A heat exchanger has been built, consisting of two concentric tubes. The outer tube is 16 inches of diameter, while the inner tube is 12 inches of diameter. The height of the tubes is 40 centimeters (15.7 inches). The annular space formed by the two tubes, allows the entry of geothermal steam, which enters 124°C (255.2 °F). The geothermal steam comes from one geothermal well than is not in operation. In the inner tube of the heat exchanger, the amount of paraffin needed to produce candles is placed. After 30 minutes the paraffin is melted, it incorporates other inputs such as color and odor. After liquid form, the liquid mass is poured into molds that have the shape of candles. 2. Prototype for milk pasteurization: Water is heated up to 80 °C (176°F), in a copper coil (wound in a geothermal pipe). The water is used as a source of heat and is passed through a heat exchanger (two tubes). Where the inner tube is made of stainless steel and is the one that holds up to 40 bottles of freshly milk. Pasteurization is achieved when the milk is maintained for 30 minutes at 63°C (145.4°F). The temperature of the geothermal pipe (reinjection water) is 184°C (363.2°F). Both prototypes can be put at the service of the local communities, which are around the geothermal plants in El Salvador. With the intention that people with limited resources, can use them for an improvement in the economy of their homes.