Description of the technological object
The technological object of control is the PM headbox.
purpose of the process control system
The main task is to control the headbox contours as accurately as possible. Precise level control in the headbox. Precise control of the total headbox pressure. Problem of the problem for the total pressure loop on the ratio of the outflow velocities and the mesh velocity (f / f lux).
The system is built both locally and as part of a complex. When building in local execution, a Siemens Simatic programmable logic controller of the S7-200 series is used. Visualization is performed on Siemens Simatic OP170 operator panels. The complex uses a Siemens Simatic PLC programmable logic controller of the S7-300 series. Visualization is performed on Scud systems WinCC or Citect. Rosemount pressure transmitters (USA) are used. Cable products from Belden, LappKabel.
Results and effect of implementation
The introduction of an automated process control system made it possible to reduce the yield of defective products by 5-10% through fluctuations in the level of mass in the headbox. The breakage is noticeably reduced. The automatic f / f lux setting allows you to produce products with a stable mechanical strength of the paper.
The payback period of the process control system, depending on the configuration, is from 3 to 12 months.