Falling film evaporator is an important equipment for food processing, which can be used in different types of food processing production lines. Benyou uses the advanced Siemens PLC system as the control master station to achieve the goal of efficient food processing. On the whole, the whole falling film evaporator system has the characteristics of high cost performance and strong practicality.
For the liquid level control of the material balance tank, a high, medium and low liquid level gauge is installed above the cylinder of the balance tank, and its output signal enters the PLC system. The pneumatic valve switch on the balance tank is controlled by PLC to ensure the liquid level balance in the balance tank. At the same time, the current liquid level is displayed on the operation interface, and the high and low level alarm can be realized.
When the low liquid level alarm of the feeding balance tank is caused by the interference of feeding and other reasons, the pneumatic valve for replenishing water will automatically open to replenish soft water to prevent the evaporator from dry burning.
The electromagnetic flowmeter installed on the material pipe of the evaporator detects the material flow and transmits the signal to the PLC. The PLC controls the frequency of the feed pump, so as to ensure the constant material flow in the pipe. At the same time, the flow can be displayed on the operation interface.
The temperature sensor installed in the I-Effect body detects the first effect temperature and transmits the signal to the first effect steam regulating valve to control the steam flow. At the same time, it receives the sugar degree signal of the sugar degree meter, and the temperature can be set according to the production situation.
A liquid level transmitter is installed at the bottom of the IV effect concentrated juice tank, which can output standard signals to PLC. PLC controls the frequency of the frequency converter of the discharge rotor pump to keep the IV effect liquid level at the set value, so as to prevent the liquid level from being too high or the rotor pump from running idle due to lack of material. At the same time, the current liquid level is displayed on the operation interface.
The sugar content of the discharged material is detected by the sugar content meter installed on the discharge pipe of the rotor pump, and this signal is transmitted to the PLC. The PLC neutralizes the sugar content signal to control the discharge. If the sugar content meets the requirements, the discharged material will return to the balance tank if it does not meet the requirements.
The vacuum pressure transmitter measures the vacuum degree of the evaporator, and the vacuum regulating valve adjusts the vacuum degree to make it constant. The air inlet of vacuum pump is controlled by pneumatic butterfly valve.
CIP cleaning is consistent with the direction of material pipeline. Install a reasonable number of spray balls in the separator and separation bin of the evaporator, the spray times and time can be automatically set during the cleaning procedure, and the pre concentration and post evaporation can be automatically cleaned independently according to the procedure.
It is convenient to adopt advanced control methods. All parameters of the system are stable during operation, which is convenient to adopt advanced automatic control (PLC and human-machine interface control), and the cost of control equipment is relatively low, so it is convenient to realize full-automatic control.
