In the pulping section of the modern paper industry, the vibrating screen for paper machine is a core equipment for pulp purification and screening. Its performance directly affects the subsequent paper forming quality and production efficiency, and it is widely used in the pretreatment section of various pulps such as wood pulp and waste paper pulp.

In terms of working principle, the vibrating screen generates directional vibration through an electric motor driving an eccentric block, making the screen frame drive the screen mesh to perform high-frequency, small-amplitude reciprocating motion. When the pulp enters the screen body from the feed inlet, under the action of vibration, the qualified fibers (undersize) that meet the process requirements pass through the screen mesh gaps and enter the next process; while the pulp residues, impurities, etc. (oversize) are transported to the slag discharge outlet along the inclined direction of the screen surface and discharged, thus completing the separation and purification of the pulp.

In terms of structural design, the vibrating screen is mainly composed of five key parts: first, the screen body, which serves as the main body for pulp bearing and separation, mostly made of stainless steel to ensure corrosion resistance; second, the vibration system, including the motor, eccentric block and shock-absorbing spring, among which the shock-absorbing spring can effectively reduce the impact of vibration on the equipment foundation; third, the screen mesh, as the core filtering element, stainless steel woven mesh, punched mesh, etc. can be selected according to the pulp type, and its mesh number should be determined in combination with the paper variety requirements; fourth, the feeding and discharging device, the feed inlet is usually equipped with a deflector to avoid direct impact of pulp on the screen mesh, and the discharge outlet needs to match the feed height of the subsequent equipment; fifth, the transmission device, some large-scale vibrating screens are equipped with a speed reduction mechanism to accurately control the vibration frequency.

In practical application, the vibrating screen has significant advantages: first, high purification efficiency, high-frequency vibration can effectively avoid screen mesh blockage, ensuring that the fiber passing rate is stably above 95%; second, convenient operation, the vibration frequency can be flexibly changed by adjusting the motor speed to adapt to different pulp concentrations (usually the treatment concentration is 0.8%-3.0%); third, low maintenance cost, the screen mesh adopts a quick-dismantling design, and the replacement time can be shortened to less than 30 minutes, reducing the equipment downtime.

With the development of the paper industry towards “high efficiency, energy saving and environmental protection”, the vibrating screen is also constantly upgraded. For example, the intelligent frequency conversion control system is adopted to realize the automatic adjustment of vibration parameters, or the screen mesh structure is optimized to improve the screening accuracy of fine components, further meeting the strict requirements of high-grade paper and special paper production for pulp purity.