Heat exchange in a chamber apparatus with a circulation circuit during cheese masses production

Abstract

Chamber heat exchangers are used in various branches of the food industry. Different types of stirrers are used in them as the means of intensifying heat transfer. They also give the devices the function of mixing devices. Grinding mechanisms are installed in some designs, which also affect the heat transfer and hydrodynamics of the movement. Grinding and mixing devices are especially widely used in the production of composite products. During heat treatment, uniformity of heating of the whole mass and the same duration of action of the maximum temperature is important for many products. In such cases, it is advisable to use chamber heat exchangers with a circulating circuit for processing thermolabile products. The heat exchange in such a device is complex due to the hydrodynamics of the product. Studies of the heat exchange process in a capacitive device with a circulating circuit are relevant. In particular, the establishment of the criterion equation of heat transfer to determine the heat transfer coefficient from the wall of the device to the product. The article deals with the peculiarities of heat exchange when using chamber heat exchangers with a stirrer and a circulating circuit. The results of research on the heat exchange process at the production of composite products on the basis of cottage cheese are presented. The process of heating the mass is influenced by its movement through the circulating device and in a closed circuit. Therefore, to study the effect of purely mechanical treatment on the heating process of the product, we studied the change in the temperature of the mass at the outlet of the circulation circuit without the supply of a heating agent. According to the results of the research, it was found that the circulation of the product in a closed circuit allows ensuring uniform heating and reduces the duration of the process. And for portions of the product weighing up to 5 kg, the required temperature can be achieved even only through machining. The criterion equation of heat transfer to determine the heat transfer coefficient from the wall to the product was obtained by the method of dimensions. A circulation number is entered, which is the ratio of the volume of the circulating product to the volume mixed by the stirrer.