Shaker Screen Frame Rib Density for Rigidity
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Solution Overview
Problem
Existing sifting screens used in drilling operations for oil and gas face issues with transmitting vibratory motion effectively, leading to excessive 'whipping' and premature failure due to inadequate rigidity, despite reinforcement measures.
Innovation Solution
A screen frame design with a higher density of plastics ribs between clamped portions than unclamped portions, combined with metal ribs for increased rigidity, and a wire mesh structure to enhance stability and weight distribution, allowing for efficient vertical and lateral vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the screen frame is made from plastics material with reinforcing ribs, then weight is reduced, but rigidity is insufficient leading to excessive whipping
Solution Approach 1:
The patent applies different rib densities in different locations: higher rib density in unclamped regions and lower rib density in clamped regions. This local differentiation optimizes rigidity where needed (unclamped areas) while maintaining overall frame flexibility and weight efficiency.
Solution Approach 2:
The screen frame combines plastics material with embedded metal wire structure to create a composite construction. This provides the lightweight advantage of plastics while incorporating the strength and rigidity of metal, resolving the contradiction between weight reduction and rigidity requirements.
2Strength
If the number of ribs per unit length is increased, then rigidity is improved, but weight increases
Solution Approach 1:
Instead of uniformly increasing rib density across the entire frame, the patent concentrates higher rib density only in unclamped regions where rigidity is most needed to prevent whipping. Clamped regions maintain lower rib density, optimizing the weight-strength balance.
Solution Approach 2:
The patent varies the rib density parameter spatially across the frame structure. By changing the number of ribs per unit length from place to place based on local requirements, it achieves adequate rigidity with minimal weight.
3Strength
If metal wire reinforcement is added, then rigidity is improved, but manufacturing complexity increases
Solution Approach 1:
The metal wire reinforcement is embedded within the plastics material during the molding process, creating an integrated composite structure. This approach adds strength while avoiding complex post-assembly steps, as the reinforcement becomes part of the frame during manufacturing.
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
The design provides increased rigidity without significant weight increase, reducing erratic solids conveyance and prolonging screen life by effectively transmitting vibratory motion and maintaining efficient separation of solids from liquids.
Implementation Method 1
the shaker vibrates the sifting screen or screens, to aid the sifting process
Data Source
AI summary
The invention relates to a screen frame adapted for use in a shaker and to which woven wire mesh is to be attached, comprising an outer perimeter and a plurality of plastics ribs extending between opposing regions of the perimeter, the frame being arranged such that, when fitted in a shaker to which it is adapted for, a portion of the opposing regions is clamped in place and a portion of the opposing regions is not clamped with the number of plastics ribs per unit length for the clamped portion greater than the number of plastics ribs per unit length for the unclamped portion, and to a shaker comprising at least one such screen frame.