Technical economic study of projects for cooking crystallized fruits by using water steam

Abstract

This technical economic study shows the results of three constructive projects, and which one is more economically viable concerning the water steam consump¬tion for heating pans of candied fruits in a food industry. The thermal analysis was emphasized on to determine the ideal constructive form of the necessary equipment for the process. Three forms of water steam use were compared for the heating of the pan: the use of the steam in a direct form, injecting the steam directly inside the pans, the use of the steam in an indirect form, heating the mixture by envolving the pan, and the steam use in an indirect form, heating the mixture by inserting a steam circulating coil in the pan. The study was based on an actual operation of an industry which uses steam in an indirect form. The steam was discharged after use. The analysis calculated the energy amount neces¬sary for the fruits cooking cicle. After that, for each form of steam use, it was cal¬culated the necessary steam rate and the cost to get it. The study shows that there is not a significant difference between the last two processes, which use steam in an indirect form, and that the use of direct water steam injection process is much more economic, with a financial reduction of 59,4%.