A NEW FLOW CALORIMETER FOR THE DETERMINATION OF THE ISOBARIC HEAT-CAPACITY OF VAPORS

A new flow calorimeter has been constructed to determine the isobaric heat capacity of vapors, especially multicomponent vapors. The calorim eter is capable of operation up to 673 K acid 20 MPa. A novel design e ncloses the innermost part of the calorimeter within a double set of t hick-wall, aluminum shields, replacing the traditional constant temper ature bath, to minimize heat loss and precisely control the calorimete r temperature. An upper copper block within the outer shield is used t o preheat the fluid while a lower copper block within the inner shield further heats the fluid to the operating temperature. Such a structur e and temperature-controlling arrangement allow easy component replace ment and operation. The apparatus was tested by determining the heat c apacity of benzene and the benzene-carbon tetrachloride binary system at atmospheric pressure with an experimental error of less than 0.7%. Results for the two binary systems benzene-chloroform and benzene-acet one at 101.3 kPa and about 515.0 K are also given.