stright hydrocarboms
the stright hydrocarbons are a group of fluids composed in various proportions of the two elements hydrogen and carbon. Those having significance as refrigerants are methane, ethane, butane, propane, enthylene, and isobutane. all are extremly flammable and explosive. also, since all act as anesthetice in varying degrees, they are consiered mildiy toxic. althought none of these compoun ds will absonrb moisture to any appreciable extent, all are extremely miscible with oil under all condition.
although a few of the straight hydrocarbon (butane, propane, and isobutane) have been used in small quantities for domestic refrigeration, their used is ordinarily limited to special applications where an experienced attendant is on duty. ethane in ultralow temperature applications, usually in the lower stage of two- and three-stage cascade systems.