There are blades on the shaft of the rotor of the pressure screen, which are commonly known as rotors. The gap between the rotor and the screen basket is adjustable. When the rotor rotates, the rotor moves along the surface of the screen drum, and the pressure difference near the head of the rotor increases, generating positive pressure. When the positive pressure continues to increase, good pulp passes through the screen basket. As the gap between the tail of the rotor gradually increases, local negative pressure appears in this area. When the negative pressure generated makes the absolute value of the pulp pressure inside and outside the screen basket equal, the pulp stops screening. When the negative pressure continues to increase, part of the good pulp outside the screen basket returns to the screen basket through the screen basket, which plays a role in recoil of the pulp clumps and coarse fibers adhering to the screen basket, thus ensuring the normal operation of the pressure screen. The negative pressure is the largest at the trailing edge of the rotor, and the negative pressure behind the rotor gradually decreases. The pulp relies on the pressure difference and the push of another rotor to start the next cycle again.
The Inflow pressure screen filters and separates the pulp through the screen holes and screen gaps on the screen drum, and will discharge larger impurities and undissociated fibers, while qualified fibers will pass through the screen holes to the next process. This process effectively improves the quality of pulp.
In addition to removing impurities, the pressure screen can further refine the fibers in the pulp, ensure the uniformity and fiber distribution of the pulp, and improve the physical properties of the paper.
1. The internal flow design has high screening efficiency: the pulp will flow from the inside of the screen basket to the outside, so that the pulp will encounter less resistance when passing through the screen drum and improve the screening efficiency. It can also reduce the fiber entanglement phenomenon and avoid equipment blockage.
2. Low maintenance cost and long life: The main components of the pressure screen (rotor, screen basket) are made of wear-resistant materials and have a long service life. The pressure screen has a simple structure and adopts a modular design, which is convenient for replacing parts to reduce maintenance costs and maintenance time.
3. The screening process of the internal flow pressure screen is gentle, which reduces damage to the fiber, can effectively protect the length and structure of the fiber, and reduce the loss of fiber, which is very necessary to improve the quality and uniformity of paper.
4. High automation: The system can be automatically controlled, the screening can be flexibly adjusted, the operation process can be simplified, and human intervention can be reduced to improve production efficiency.
Model | Inlet consistency (%) | Inlet pressure (MPa) | Motor power (KW) | Capacity (t/24h) |
SHN0.6 | 0.5-1.2 | 0.1-0.3 | 15-22 | 20-30 |
SHN0.9 | 18.5-30 | 25-60 | ||
SHN1.2 | 22-37 | 30-80 | ||
SHN1.5 | 30-45 | 40-120 | ||
SHN2.0 | 37-55 | 80-210 | ||
SHN2.5 | 37-75 | 100-230 | ||
SHN3.5 | 45-110 | 140-280 | ||
SHN4.5 | 55-132 | 180-350 | ||
SHN6.0 | 75-160 | 230-500 |