Helical Ramp Inlet for Top Separator Pulsation Reduction
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Solution Overview
Problem
Existing top separators in pulp manufacturing experience mechanical load and wear due to pulsations caused by the screw feeder blocking the inlet opening, leading to inefficient material transport and increased costs.
Innovation Solution
A top separator design featuring a helical ramp-like inlet arrangement that matches the screw feeder's pitch and width, allowing the material suspension to enter along the entire length of the ramp, reducing blockage and pulsations by aligning with the rotational direction of the screw feeder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an inlet opening is provided in the bottom portion of the screen basket, then the chip slurry can be supplied into the top separator, but the screw flight temporarily blocks the inlet opening causing pressure build-up and mechanical pulsation
Solution Approach 1:
A ramp-like structure is introduced as an intermediary element between the inlet opening and the screw feeder. This ramp structure receives the chip slurry at its lower end and transports it along its inclined surface to the screen basket, preventing direct contact between the inlet opening and the screw flight, thereby eliminating the blocking problem and associated mechanical pulsations
2Reliability
If a hole is provided in the screw flight to prevent complete blocking of the inlet opening, then pressure build-up is reduced, but material transport efficiency is impaired
Solution Approach 1:
The ramp-like structure serves as a mediator that completely prevents the screw flight from blocking the inlet opening, eliminating the need to compromise transport efficiency by creating holes in the screw flight. The ramp structure provides a continuous material flow path that maintains full blocking capability while preventing pressure build-up through its elevated discharge point
3Reliability
If the screw feeder is made bigger and stronger to handle the mechanical load, then reliability is improved, but cost and device complexity increase
Solution Approach 1:
The ramp-like structure acts as a protective intermediary that eliminates the source of mechanical pulsations and excessive loads on the screw feeder. By preventing the blocking problem at its source, the system maintains screw feeder reliability while using standard, cost-effective designs rather than requiring oversized and complex reinforced structures
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design minimizes mechanical load on the screw feeder, reduces wear, and maintains or increases chip transport capacity without enlarging the separator or increasing rotational speed, ensuring efficient and pulsation-free material transport.
Implementation Method 1
a ramp-like structure, which extends in a helical path with essentially the same pitch as the screw flight of the screw feeder
Implementation Method 2
a screw feeder arranged in the screen basket for conveying a chip slurry from a lower end of the screen basket to an upper end thereof
Implementation Method 3
liquid is withdrawn outwardly through holes, slits or perforations in the wall of the surrounding screen basket
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a top separator for a treatment vessel for the manufacture of pulp from lignocellulosic material and comprises a housing, an interior casing arranged in the housing and having a bottom portion, a screen basket arranged in the interior casing, a screw feeder vertically arranged in the screen basket, and an inlet arrangement comprising an inlet opening, wherein the inlet arrangement comprises a helical ramp structure, which extends from a first, lower level, at which the inlet opening is located, to a second, higher level, which is in level with the bottom portion of the interior casing.