EXPERIMENTAL INVESTIGATION ON NATURAL CONVECTIVE HEATING OF MILK

Abstract

ABSTRACTIn this article, the behavior of heat and mass transfer relation during khoa making has been investigated. Various indoor experiments have been performed for simulation of developed thermal model for maximum evaporation during heating of milk. The data obtained from experimentation have been used to determine values of constant “C” and exponent “n” by simple regression analysis. Based on the values of “C” and “n,” convective and evaporative heat transfer coefficients for milk were determined. It was observed that the convective and evaporative heat transfer coefficients decrease with the increase in rate of heating (varying voltage). It was also observed that convective and evaporative heat transfer coefficients increase with the increase in operating temperature. The rate of increment of evaporative heat transfer coefficient is higher than the convective heat transfer coefficient. The experimental error in terms of percent uncertainty was also calculated.PRACTICAL APPLICATIONSThe traditional method of khoa making (i.e., open pan evaporation process) requires a large quantity of energy and in the present era, energy saving is needed to pay sufficient attention. In rural India, generally, wood, cattle dung, coal, kerosene, etc. are used in open chulah as fuel for khoa making which is hardly 8–10% thermally efficient. A number of research articles are available in the literature explaining the mechanization of khoa making process. But even today, the khoa making technology in rural India much remains the same. Thus, by keeping energy saving aspect in mind, the traditional method of khoa making has been further explored.