The Rotation mixing system adopts human-computer interaction and management functions, with the ability to process information in Chinese, and adopts Chinese prompts in the menu mode. The operator can select and perform various operations by function Casgood or cursor movement. The system provides a fixed recipe library. There are as many as 100 kinds of formulas. The operator can query, modify or assign a working formula to the stored formula, or temporarily input and erase a formula. The system has dynamic display and printing functions. In the process of dosage, the computer can display the dosage control flow chart on the CRT screen and indicate dynamically with the cursor, which can display the title and dosage weight at the same time, etc., so that the operator can understand the dosage situation at a glance. The printer can print in Chinese. The system can provide various production information reports to the production management department.
020-34563445The rotary mixing system is a key process in the mixing production, and its batching accuracy directly affects the quality of the mixed products. Due to the changes in factors such as drop, feeding impact, process parameters, and material properties, the model of the Batching system is nonlinear and time-varying. The overall fuzzy predictive PID control mode is adopted, and monitoring and control are carried out in accordance with the set process formula.
The feeding system adopts human-computer interaction and management functions, has the ability to process Chinese information, and provides Chinese prompts in the menu mode. Operators can select and perform various operations by using function keys or cursor movement. The system provides a fixed recipe library. There are as many as 100 recipes. Operators can query, modify or specify a working formula for the stored formulas, and can also temporarily input and erase a formula. The system has dynamic display and printing functions. During the batching process, the computer can display the batching control flow chart on the CRT screen and provide dynamic indications with a cursor. It can simultaneously show the name and batching weight, etc., allowing the operator to have a clear understanding of the batching situation at a glance. The printer can print in Chinese. The system can provide various production information reports to the production management department.
In order for the PLC of the mixer to perform the function of batching control, the PLC needs to have functions such as weight signal input, weight signal processing, and processing result output. The following is an introduction to the batching steps completed by the PLC program:
The weight signals of the two batching machines are respectively converted by the weighing instrument and A/D conversion and then enter the PLC. The weighing instrument outputs parallel BCD codes, which are converted into binary codes by the program and stored in the data register of the PLC.
2. According to the requirements of the batching process, the feeding process of all raw materials includes a point operation process to ensure the accuracy of batching. The operator in charge of batching inputs the raw material formula, which includes the feeding amount, lead time and precision of various raw materials. The relationship between them and the batching process is: when the weight of the raw material is less than (feeding amount - lead time), add the material. After the feeding stops, the PLC compares the weight of the raw materials with the feeding amount. If it is within the allowable tolerance range, it is considered qualified. At the lower limit of the allowable tolerance, point feeding should be carried out. If it exceeds the upper limit of the allowable tolerance, it is considered an out-of-tolerance.
3. As the mixer adopts an accumulation scale, that is, several raw materials are added in sequence by one scale, the weight obtained is the sum of all the raw materials except the first one. In the PLC program, the weights of several raw materials need to be separated to obtain the weight of each raw material. The program processes it as follows: When weighing each raw material, record the weight at this time. When weighing, subtract the previously recorded weight from the total weight, and the result is the actual weight of this raw material.
4. The raw materials adhering to the scale body cause deviations in the batching, and it is necessary to carry out peeling treatment. The method of peeling is similar to the above one. That is, when the "peeling" button is pressed, the PLC records the weight at this time, which is the reference zero point. When weighing, subtract the reference zero point value from the total weight, and the result is the accurate weight of the raw material.
5. After the feeding stops, there is still some raw material remaining between the screw Feeder and the hopper scale that needs to fall into the hopper scale. To ensure that the batching accuracy meets the requirements, this weight needs to be considered in the program. In the program, "lead time" is used to represent this value. When the weight of the raw material reaches (feeding amount - lead time), the feeding stops, and the raw material remaining in the air makes up for the difference in lead time. So as to meet the precision requirements.
6. Considering that the batching may stop due to sudden power outages, in order to prevent the waste of the prepared raw materials, the weight of the prepared raw materials needs to have a power outage protection function. In the program, these weight signals are stored in data registers that can be retained after power failure.
