The pressure screen basket, as the core component of the pressure screen, has a direct impact on the screening efficiency of the equipment. With the advancement of technology, the opening design of screen basket has also undergone an evolution from round hole type to plate slot milling type, and now widely used slotted type.
Structural Design of Slotted Screen Basket
The design of the slotted inflow and outflow screen basket includes multiple vertical bars evenly arranged around the circumference of the screen basket. The top is equipped with an upper flange to stabilize the top of the rod, while the bottom is equipped with a lower flange to secure the bottom of the rod. Multiple middle rings are also set from top to bottom in the middle to further stabilize the middle of the rod. This design makes the pressure screen basket suitable for use as both an inflow screen basket, where pulp flows from the inside of the screen basket to the outside, and an outflow screen basket, where pulp flows from the outside of the sieve cylinder to the inside. Regardless of the usage method, the flow direction of pulp is crucial, and different operating conditions also determine the application and classification of pressure screen basket designs. When used as an inflow screen basket, the vertical rod will be inserted into the inner wall of the middle ring; When used as an outflow screen basket, it is inserted into the outer wall of the middle ring.
Pulp Flow of Pressure Screen Basket
In addition, the design of the pressure screen basket also takes into account the optimization of pulp flow direction. On the vertical rod, it is divided into a drainage section and an installation section along the flow direction. The installation part is specially designed to easily insert into the slot and weld, ensuring the stability of the rod. At the same time, the width of the drainage section is designed to be greater than that of the installation section in the circumferential direction, thereby forming specific slot between adjacent rods. This screening structure presents the characteristics of narrow inlet and wide channel along the direction of pulp flow, effectively improving screening efficiency.
Pressure Screen Basket Design Features and Processing Details
In order to further simplify the assembly process of vertical rods, the pressure screen basket slot is designed in a combination of conical and straight segment slots. The circumferential width of the conical groove gradually narrows along the flow direction, and its minimum width remains consistent with the width of the straight groove. This design allows the installation part of the vertical slot to be smoothly pressed into the slot, with the tapered section slot playing a precise centering role, while the straight section slot is responsible for further fixing and reinforcement.
The design of the slot takes into account the flow characteristics of pulp.
In the circumferential direction, one side of the vertical rod’s drainage section is the upstream face, the other side is the downstream face, and the end face of the rod is the top face. Both the upstream and downstream surfaces are inclined against the flow direction of the pulp, and their inclination directions are opposite. The top surface is inclined from the back surface to the upstream surface. The inclination of the upstream side is greater than that of the downstream side, and its length is also longer. This design forms a narrow entrance between the top of the backing surface and the middle of the adjacent facing surface, which helps to efficiently screen the pulp. At the same time, there are chamfers between the top surface and the facing surface, as well as between the top surface and the backing surface, for transition connections to ensure that the pulp can smoothly pass through the slot.