Beaten pulp system control

The closed-loop control of soft measurement of refiner beating degree is the core of the refining system which is a control software module successfully developed through HollySys’ implementation of nearly a hundred refiners. The production lines produce special paper types, high-quality office paper, and different types of packaging paper, receiving good feedback from users.

The DCS of the beatenpulp production lines optimises automation control, is able to stabilise indicators such as beating quality, stabilise pulp beating degree, and wet weight (Ww), ensuring the fulfilment of physical indicators such as paper evenness, breaking length, tightness, gloss, and tear.

DCS control characteristics:

•  The best energy settings can be set by predicting the energy needed to transport the slurry to the refiner to reduce time of depletion.

•  Highly reliable input and handling of standard power and current-ionisation degree signals

•  Top-up depleted slurry when conducting ionisation degree control

•  Input impulse to control refiner infeed to prevent control output of depletion

•  Separately demarcate based on different types of slurry, and the DCS will predict power setting values to conduct category managementbasedon the number of definite slurry types

•  Adopt mode switch to carry out control, and the program will automatically identify and convert.

Control solution for headbox

Headbox control includes air cushion headbox control, diluted water strength headbox control, and wet-end water and vacuum control solutions.

Control solution for dryer segment

During the drying process of the paper machine, the drying process will be divided into low-temperature, mid-temperature, and high-temperature sections based on the drying curves required according to the different paper types. The control system is temperature-controlled based on the designed temperature curve. The reasonable drying curve design is able to improve the product’s physical indicators. The main controls include hot pump, ventilation, exhaust, heat retrieval, and fire-safety control.