MODELING AND EXPERIMENTAL VALIDATION OF SUBLIMATIONCONDENSATION PROCESS IN SOLID-VAPOR SYSTEM
The sublimation condensation technique is one of the most convenient separation methods used commercially. The parameters that affect the deposition layer thickness in desublimation heat exchanger tubes was investigated and determined in this paper. Experimental setup was fabricated, assembled and performed at Standard Temperature and Pressure, PIEAS, Pakistan. Condenser was fabricated of stainless steel having diameter (18 mm) and total length (340 mm) at PIEAS. Four Pyrex capillary tubes were used with different thicknesses and diameters. Laboratory grade Naphthalene and Ammonium chloride was selected as sublime materials. Direct heating method was employed to separate condensable sublime material from non condensing carrier gas (Air). Concentric type single pass desublimation heat exchanger was made by placing capillary tube inside the condenser. The deposited layer thickness versus time and tube length as function of the tube diameter, thermal conductivity of sublime material, coolant temperature and type of coolant was determined experimentally. To measure thickness of desublimed material which was deposited inside very small capillary tubes is difficult to measure so the qualitative deposited weight method was employed.