A pasteurization-cooling plant is used to pasteurize and cool sour-milk products. In other words, this installation is necessary for all enterprises that work with this category of goods. In addition, this unit is equipped with an automatic temperature control and regulation system, which makes its use even more convenient.
Installation Description
Today, there are tubular and plate installations. Next will be described the device of the second type of such devices. So, the plate pasteurization-cooling installation consists of such basic elements as:
- plate heat exchanger;
- a system designed for the preparation of hot water (the composition includes a pump, injector and convection type tank).
The main purpose of this system is that it heats the products to the fermentation temperature. There is also a pump for the products themselves. Naturally, since there is an automatic system for monitoring and regulating parameters, then there is also a control panel for this system. It is important to note that the pasteurization-cooling unit is quite compact and made in a modular style. The only additional equipment is a cupper, which is a separate structural element. Regarding installation, it can be mounted in any accessible place. The result is a convenient system that has everything necessary for automatic functioning, which at the same time takes up little space.
Installation purpose
Pasteurization and cooling unit is designed to perform such actions as:
- Heated dairy product to a temperature of 55-60 degrees Celsius (separation temperature).
- Heated to a temperature of 75-80 degrees (homogenization of milk).
- Heated to a pasteurization temperature of the dairy product - 90-95 degrees.
- The equipment also conducts exposure of the goods at its pasteurization temperature for 300 seconds.
- The last operation is the cooling of the product to the fermentation temperature, that is, up to 20-50 degrees.
Assignment of elements
The plate pasteurization-cooling unit for milk is also capable of working with such liquid products as beer, juice, wine, drinks, alkalis and others. A plate heat exchanger is responsible for heating and cooling this product. All operations are carried out with a closed stream. It is also worth noting that due to the high rate of thermal efficiency of such heat exchangers, they have compact dimensions. As for the efficiency, then for all installations made on the basis of this model, it is more than 90%. All parts of the pasteurization and cooling plant that come into contact with food during operation are made of steel that is approved for use in the food industry.
The coolant in such systems is either water or brine. The heat carrier may also be water or steam. The device has a heat exchanger, which consists of plates, a bed and a pressure plate. All these parts are pulled together by fixing pins.
Installation Specifications
The pasteurization and cooling unit for milk has a certain number of technical parameters, which varies depending on the model. Next will be described the parameters of the product PBC-1.
The first and most important parameter is, of course, performance. For this equipment, it ranges from 1000 to 10,000 l / h. The next parameter is the temperature of both the coolant and the coolant in the system. The difference between the output products and these carriers is from 2 to 4 degrees Celsius with a ratio of 1/3. All models also differ in their dimensions, but not too much, and the parameter itself is not very important. The material used for the manufacture of the plate is steel grade 12X18H10T. The plate thickness is 0.6 mm. The maximum temperature for PBC-1 is 150 degrees.
The principle of operation of the pasteurization and cooling plant
In an automatic plate-type system, the workflow proceeds as follows.
There is a milk collector at the factory, which is connected to the surge tank of the device. From the collection box, products come to this module either by means of a pump or by gravity. It is important to ensure that the milk level does not drop lower than 300 ml, otherwise the air will suck into the milk pump. After that, the pump pumps the products to the first section of the heat exchanger. Here, the dairy product is heated, as there is heat exchange with the hot milk following from the pasteurization site through the curing agent. Here, the temperature of the object rises to about 47-50 degrees Celsius, after which milk is pumped through the cleaner to the second section. Here the product is reheated. Heat transfer occurs with the same pasteurized milk that underwent pre-type heat transfer in section number 1. After this procedure is completed, the milk enters the pasteurization section, which is considered the third. Here, coolant is already ordinary water. Heat transfer lasts until the dairy product is heated to 76 degrees Celsius.
Further, as described above, pasteurized milk is returned through sections 1 and 2, where it gives off heat, thereby cooling to 20-25 degrees. After that, the product is pumped to the cooler, where the temperature drops to 5-8 degrees. As a result, fully chilled milk is fed to storage tanks. This completes the work of the pasteurization-cooling plant for milk.
Tube type installation
The description above concerned a plate-type device, however there is also a second one - tubular. Such devices consist of a tubular apparatus, two centrifugal pumps, a check valve, condensate drainage units, as well as a control panel designed to control automatic control and regulation devices.
Description of the elements of the unit
The tubular pasteurization-cooling unit includes a heat exchanger. It consists of two cylinders, the upper and lower, which are interconnected using a pipe system. Tube gratings are welded into the ends of these cylinders, each of which has 24 pipes with a diameter of 30 mm. The grilles are made of stainless steel and also have short channels. These channels connect all 24 pipes. The result is a continuous-type coil with a total length of approximately 30 m. The cylinders, in turn, are closed by caps, which are equipped with rubber seals. This is done not only in order to create a completely sealed structure, but also in order to separate the short channels from each other.
In the operation of the device there is steam, which upon receipt falls into the space between the cylinders. After it has worked, it is removed from the device in the form of condensate using thermodynamic type steam traps.
The essence of the unit
The milk that needs to be heated moves in turn through the upper and then the lower cylinders. It moves along the in-tube space. The unit also has a valve that controls the flow of steam. It is located immediately at the entrance of this substance. At the outlet of the device there is another valve, but a return type. It works in automatic mode, and its main goal is to return the unpasteurized milk for a second operation. To perform this function, the mechanism is connected to the temperature sensor through a device such as a temperature controller, which is also located at the outlet of the milk. Since steam and milk pressure is present in the device, the unit also has several pressure gauges.
It is worth noting that the treatment begins with the lower cylinder, where there is steam that heats the milk to a temperature of 50-60 degrees. Milk enters the lower part under the influence of the first centrifugal pump. For pumping to the top, a second pump is used. In the upper part, pasteurization of the substance to a temperature of 80-90 degrees Celsius is carried out.
The main advantages of the installation
This equipment is widespread, as it stands out for a number of significant advantages that are important for this industry. Firstly, the device fully complies with thermal conditions both during pasteurization and during cooling. At the same time, the desired performance is maintained. Secondly, the execution of a modular type minimizes the size of the device, which makes it compact, and therefore convenient for placement and use.