The Core Function of The Pressure Screen Basket
In the pulp and paper production process, the pressure screen is the key screening equipment, and its core component, the pressure screen basket, plays an important role in pulp screening. The screen basket achieves effective separation of fibers and impurities through a precisely designed perforated structure, which directly affects the quality grade of the final paper product. Modern screen basket need to meet three basic requirements: precise separation accuracy, durable wear resistance, and stable fluid dynamics characteristics. The working environment of a typical pressure screen basket faces multiple challenges, including continuous high-pressure pulp flushing, mechanical wear from various impurities, and chemical corrosion.
Precision Manufacturing Process of Pressure Screen Basket
Material Selection and Structural Design
Modern pressure screen basket typically use high-strength stainless steel plates with a thickness of 8mm as the base material, which combines good mechanical strength and corrosion resistance. There are two mainstream forms in structural design: integral slotted and rods embedded. The overall slotted screen basket is processed directly on the steel plate through water jet cutting technology to form a burr free fluid channel; The bar inlay type uses precision arranged stainless steel rods to form screening gaps, and both have their own applicable process scenarios.
The water jet cutting process has significant advantages over traditional mechanical washing and grinding. This technology uses ultra-high pressure water flow (usually above 350MPa) combined with abrasives for cutting, with a cutting flatness error of no more than 0.02mm, and no stress concentration phenomenon will occur at the end of the groove. This processing method is particularly suitable for handling fine sieve seams in the range of 0.15-0.5mm, ensuring that the fibers will not be damaged again when the pulp passes through.
Surface Strengthening Treatment Technology
To improve the service life of screen basket, surface modification technology is commonly used in the industry. The hard chrome plating process is one of the most mature solutions. By depositing a 50-100um thick chromium layer on the surface of the screen basket, the wear resistance can be improved by 3-5 times. In recent years, the developed corrugated reinforcement structure can increase structural stiffness and optimize fluid flow characteristics by forming specific corrugated patterns on the surface of the screen basket, resulting in a 15-20% increase in processing capacity under the same porosity.
Some high grade models adopt a multi-layer composite screen basket design, which achieves graded screening through the combination of different aperture screen basket. For example, a three-layer screen basket structure is used, with the first layer having a 0.3mm sieve gap for removing large particle impurities, the middle layer having a 0.15mm sieve gap for processing medium particles, and the final layer having a 0.1mm sieve gap for fine screening. This design reduces the fiber loss rate to below 60% of traditional structures.