Heat and mass transfer from a rotating disk with phase change

Experimental measurements were made in a rotating disk evaporator. The condensate flow rate, pressure, and temperature across the disk and the rotational speed of the disk were measured. The overall heat transfer coefficients were determined from the above measured data. Tests were carried out on a copper disk with and without a wiper on the evaporation surface of the disk and on a monel disk with a wiper. Evaporation heat transfer coefficients were calculated based on the thermal resistance method. A study of impinging, rotating, and condensing flow was carried out. An integral method was used to obtain the results for the impinging flow case. Two impinging conditions are considered: A liquid boundary layer only, without a vapor drag effect and two boundary layers, liquid and vapor, with a vapor drag effect. The results show that the copper disk with a wiper yields higher condensation rates, evaporation heat transfer coefficient, and overall heat transfer coefficients than does the copper disk without a wiper. Also, the copper disk with a wiper yields higher values than does the monel disk with a wiper. The theoretical studies show that the effect of vapor drag on the condensation heat transfer is small for impinging flow.