The working principle of AKD surface sizing agent is introduced

In the papermaking process using AKD surface sizing agent, it is necessary to add a small amount of AKD and PAM additives. Because these additives are easily decomposed, they are not suitable for the use of traditional centrifugal pumps during the addition process. Two paper machines were changed from acid sizing to neutral sizing. The original use of domestic electric metering diaphragm pump. After more than a year of use, the following problems are reflected: large flow fluctuation (5%-10%), difficult flow regulation, high failure rate, and great impact on product quality and cost. Therefore, a pneumatic diaphragm pump detection and control system is designed.

Working principle

The AKD solution of the AKD surface sizing agent is raised to 0.1-0.3mpa by a pneumatic diaphragm pump. After the pressure is stabilized by a voltage regulator, the pulsation is reduced, and the flow change value is converted into a current signal by a torus flow transmitter. The current signal is fed into the regulator. In the regulator, the difference between the signal and the given value is calculated by proportion and integration, and then the corresponding regulating current is output and input to the electrical converter. The electric converter converts the current signal to the gas signal, pushes the pneumatic film lined plastic regulating valve, regulating the opening of the valve, and achieves the purpose of automatic flow control. Because the traditional DDZ instrument is selected and the fixed value adjustment mode is adopted, the instrument selection and adjustment parameter setting are not explained. In addition, the photoelectric relay installed in the press part of the paper machine reflects the broken paper state, outputs the contact signal, and controls the opening and closing of the solenoid valve. When the paper is broken, the pneumatic pump stops working temporarily to achieve the purpose of not adding AKD when the paper is broken or stopped.

Pneumatic diaphragm

The pneumatic diaphragm pump uses compressed air as the power source. It can pump various particles and high viscosity liquids. No need for irrigation, suction lift up to 7m, lift up to 50m, outlet pressure up to 0.6MPa, good flow performance, the larger particle size 1mm, by adjusting the input air pressure can be stepless adjustment of the outlet pressure. The diaphragm in the pump completely separates the liquid from the moving parts. Because compressed air is used as a power source, it is suitable for use in flammable, explosive and humid places.

Above is the working principle of AKD surface sizing agent, I hope to help you.