After the steel coils are rolled by the continuous rolling mill, the cleaning machine carries out acid washing and soaking in acid washing trough. In electrolytic bath, electrode electrolysis is used to degrease. Then it is washed and dried and delivered to bell-type furnace for annealing. After the steel plate passes through the cleaning work procedure, emulsion residue of rolling mill and other impurities may be removed effectively so that the marks on the plate caused by convection and bonding between steel plates of the annealing furnace may be removed to improve surface quality of steel plates. As users put forward higher and higher requirements for quality of cold rolled products, cleaning machine unit plays a more and more important role in production of cold rolled plates.
The cleaning machine unit adopts distributed control system with Siemens products as the core. Good quality and performance ensures that the machine unit is designed to meet the technological requirements. The entire PLC control system of cleaning machine unit is divided into five parts. They perform order control for equipment at the entrance and exit, action of auxiliary equipment at hydraulic station and process section, data transmission and communication management among all equipment, band steel track and automatic function of auxiliary machine as well as tension control, linear coordination and main command speed control. The communication network formed by industrial Ethernet MPI and PROFIBUS onsite bus ensures reliable data transmission among all equipment and real-timer monitoring for operation of the machine unit. Adoption of HMI touch screen can perform data input and operation. Operators can implement simple operation and control on the touch screen.