A method and system for controlling a refiner to produce a cellulose-containing pulp product
A refiner, cellulose technology, applied in general control systems, control/regulatory systems, pulp beating/refining methods, etc., to achieve process control improvement, minimization of commissioning and testing requirements, and accurate initial control.
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example 1
[0056] image 3 Shown is a control system for a mill according to the prior art, where pulp is refined by a refiner with constant specific energy consumption. The process control parameters include the refined consistency and flow characteristics of the slurry and the specific cutter size at the station. However, these parameters do not give a statistically reliable indication or prediction of the Canadian Standard Freeness value of seminal plasma. The main components of the system shown include the pulp input, the refiner 1, the specific energy consumption of this refiner controlled by the process control system 2 via signal 6, the Canadian Standard Freeness measurement unit 3,4 and the control via valve 5 pulp slurry export.
[0057] The Canadian Standard Freeness value is read at unit 3 and the process control system 2 adjusts according to this feedback so that the refining process in the refiner 1 is more or less efficient.
example 2
[0059] Figure 4 Shown is a control system for a refiner using the present invention. as image 3 , there are feedbacks from the Canadian Standard Freeness measurement units 3 and 4, and the above-mentioned conventional process control parameters, and this feedback is the input signal 9 of the grinding paper module unit 8 . Again, here's the quality index Botnia FOX TM is used as an input value as a base value for calculating the pulping properties of the pulp fed into the control system 7 . This creates a feedforward loop 8->7->1, improving the quality of control and speed of the process. The delay of the control system using the predefined quality index information of the pulp is smaller than that of the Canadian standard freeness feedback control loop 4->3->8->7->1. In practice, this means that if a process parameter is changed, including quality indicators, it is possible to correct the operation of the refiner in 6 even before the Canadian Standard Freeness value in 4...
example 3
[0065] Figure 5 Shown is another embodiment of the invention in which a stock quantity control loop is added at 11,12,13. This allows products, such as paper, to simultaneously maintain a constant Canadian Standard Freeness value and tensile strength. like Figure 4 Central Canadian Standard Freeness values are controlled. If the flow meter 13, which measures the slurry flow rate in valve 12, receives an indication that quality indicators and some other process parameters have changed, then the amount of cellulose in 11 will be changed to ensure that the desired tensile strength is maintained or achieved or stiffness. It will be appreciated that the control loop is enabled by the predictability of the process provided by the pulp quality index and the inventive concept that this index can provide a statistically significant and stable indication of refining properties.
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