The main control functions of the variable frequency automatic Feeding machine include setting of main process parameters, interlocking start and stop of equipment, browsing and querying of main process parameters, etc. The PLC transmits the collected status of each equipment, material flow rate and position quantity to the industrial control computer through Ethernet for display, which is convenient for production process control. At the same time, the data of the actual speed of each motor, current signals, the discharge volume of the feeding bin, and the bin position signals are saved as historical records, which is conducive to the query of equipment and production failure causes.

The feeding machine is the core part of the production of raw materials for batching, and it has very high requirements for the accuracy, reliability and confidentiality of batching. The automatic feeding machine adopts the mass batching method. Various powders, granules and flakes are batched here according to the proportion input by the operator through the weighing equipment. The accuracy of the ingredients directly affects the stability of the content of the raw materials, so it puts forward higher requirements for the control system.

The automatic feeding machine is mainly composed of PLC, feeding device, weighing device, frequency converter, etc. The operator inputs the chemical composition and proportion of various raw materials through the operator station. The flow signal is converted into a 4-20mA signal by the weighing equipment and the weighing display and input into the functional module. It is compared with the set value. After the PID operation of the continuous control block, the obtained control word is transmitted to the frequency converter through the bus. The frequency converter controls the speed of the motor of the feeding device according to this signal. This enables the feeding amount of each feeding device to fluctuate slightly above and below the set value, achieving the automatic batching function. The control output can be changed by adjusting the three coefficients of proportional coefficient, integral time constant and differential time constant respectively, and a better control effect can be achieved.

In the first and second rounds of mixing, an appropriate amount of liquid should also be added to ensure the air permeability of the raw materials for the ingredients, thereby increasing the output and quality. The amount of liquid added in one mixing is related to the original liquid content of the raw materials. Add liquid for the second time to make the liquid content of the mixture reach the target value set for the second mixing and liquid addition, so as to improve the air permeability. The first liquid addition is controlled at a fixed value based on a rough liquid addition percentage. The second liquid addition is controlled by PID. After setting the liquid content of the daily standard, the current liquid content measured is compared with the target liquid content, and feedback correction is made for the given deviation to achieve automatic control of the liquid fraction.

The control system of the batching heating tank mainly accomplishes the detection and control of relevant parameters of the batching heating tank, such as the tank chamber pressure of the heating tank, the temperature of the ignition section of the heating tank, the temperature of the preheating section of the heating tank, the tank pressure, the material flow rate, and other parameters for manual and automatic control. It realizes jl control through data display screens and historical trend screens, and has functions such as alarm and historical record.

In the above-mentioned automatic regulation, manual/PID disturbance-free rapid switching can be achieved. It is required that the average values of the control or controlled quantities before and after the switching be equal. Therefore, the average values of the control or controlled quantities before the switching must be calculated first, and then the switching can be carried out to minimize the impact on the process and truly achieve disturbance-free switching. First, track and calculate the average value of the controlled quantity per minute on the upper computer at that time. Take this value as the given value during automatic initialization; When switching from automatic to manual, first track and calculate the average control quantity per minute on the upper computer at that time, and take this value as the control value at the initial manual operation. PID control can switch between manual control and automatic control without disturbance.