THE TECHNOLOGICAL STRUCTURE AND WORKING PRINCIPLE OF PLATE PASTEURIZER

ABSTRACT

In this article, you will get information about the plate heat exchanger, the pasteurizer that pasteurizes liquid food products. Also, information on its working mechanism, application and installation work is provided.

АННОТАЦИЯ

 В этой статье вы узнаете общие сведения о пластинчатом пастеризаторе, принципе работы, технических и технологических свойствах. Также предоставляется информация о его рабочем механизме, применении и работе по установке

Keywords: plate heat exchanger, pasteurizer, milk, plate, temperature, heat exchanger.

Ключевые слова: пластинчатый теплообменник, пастеризатор, молоко, пластина, температура, теплообменник.

Uzbekistan imported 22.3 thousand tons of milk and milk products from more than 30 countries in 7 months of 2022. The largest share of imported products is Russia - 8.4 thousand tons, Belarus - 3.8 thousand tons, Iran - 3.8 thousand tons, Kazakhstan - 3 thousand tons. However, 17,300 tons of milk and milk products were produced in our country during this period [1].

Thus, we can see that the demand for milk and milk products in our country is not fulfilled. Taking these into account, their production, improvement of the equipment used in production and creation of sufficient conditions are one of the urgent problems. Taking into account the above, the place and role of milk and milk products processing equipment, namely pasteurizers, is incomparable. Therefore, we have chosen a plate heat exchanger as an object of research. Types of plate   heat exchangers in general, the principle of operation and their fields of application have been mentioned above. The general view of the plate heat exchanger is presented in the following picture.

Figure 1. Plate pasteurizer:

1- holding pipe; 2-water heating tank; 3- heat exchanger; 4-milk balance tank; 5-milk pump; 6 control panel

When designing plate heat exchangers, special attention should be paid to the heat transfer coefficient [2]. Because the efficiency of the heat exchanger is closely related to the average temperature difference. Plate   heat exchanger, as we mentioned above, is widely used in the processing of many foods, including milk and dairy products. At the initial stage of the device, the processed raw material, i.e. raw milk, first enters the balance tank of the pasteurizer through the milk pump. Inside the balance tank, there is a floating sensor that turns on and off the milk pump in the upper and lower parts. If the milk is low, the valve at the bottom gives the order to the milk pump. In the opposite case, i.e. if milk reaches the upper part of the milk pump, the milk pump will be ordered to turn off. The main reason why this container is called a balance tank is that it balances the milk so that it does not decrease or increase, so it is called a balance tank. The milk from the balance tank is pumped to the recuperation section of the plate device through the second milk pumping pump.

Figure 2. Technological scheme of the plate pasteurizer:

1-water heating tank; 2- water circulation pump; 3- holding pipe; 4- heating section of the heat exchanger; 5- recuperation section of the heat exchanger; 6- cooling section of the heat exchanger; 7- milk pump; 8- milk filter; 9 - balance tank floats; 10-balance tank

When the device starts up, initially, there is no milk on the other side of the platen in the recuperation section, it will be in the space until the pasteurized milk is pasteurized and enters the recuperation in the holding pipes.

The main purpose of the recuperation stage is to heat the cold raw milk coming from the outside of pasteurized high-temperature milk and cool it. In recuperation, if we say it in soda language, it is to prevent heat loss and make efficient use of available energy in case of effective use of the temperature difference between raw milk and pasteurized milk [3].

After recuperation, the raw milk is transferred to the heating section in a relatively lumpy state. In the heating section, there is liquid on both sides of the plate, that is, milk on one side and a heating agent on the other side. As a heating agent, hot water and steam are widely used. Hot water was also used in our experimental setup. As we mentioned above in the heating section, hot milk is sent from the water heating tank to the heating section with the help of water pumps.

The milk stored in the heating section is pasteurized at the specified temperature. During the heating process, relatively cooled water returns to the water heating tank and is heated again and reused. Water heaters of different capacities can be used in the heating tank. In the heating section, raw milk is reached to pasteurization temperature and transferred to the holding pipe.

The function of the holding pipe is to destroy some microbes in the milk by keeping them at a high temperature for a certain period of time.

The length of the holding pipe is selected based on the chemical, physical and biological properties of the raw material being processed and in proportion to the milk pumping pump.

References:

1. https://stat.uz/uz/matbuot-markazi/qo-mita-yangiliklar/27005-o-zbekiston-30-ta-davlatdan-sut-mahsulotlarini-import-qilgan
2. Н.Р.Юсупбеков, Ҳ.С.Нурмуҳамедов, С.Г.Зокиров. Кимёвий  технология асосий жараён ва қурилмалар. Олий ўқув юртлари учун дарслик.-Шарқ-2003, б. 196-226
3. Gosta Bylund. Tetra Pak Dairy processing HANDBOOK. Sweden. Lund. Tetra pack processing Systems publishing 1995- pp 79-91