Stacked Screen Decks in Shale Shaker for Efficient Solids Separation

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Solution Overview

Problem

Conventional vibratory screening machines, such as shale shakers, face challenges in achieving high throughput and efficient solids separation while maintaining compactness and reducing the need for additional equipment like flow directing trays, which can hinder processing efficiency and lead to solids accumulation and equipment wear.

Innovation Solution

The implementation of a shale shaker design featuring a stack of at least two or three screen decks with inclined screening surfaces, where the decks share a common pond region for solids and liquid processing, eliminating the need for flow directing trays between decks and enhancing processing capacity and efficiency by maintaining a compact form factor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional shale shakers use flow directing trays between screen decks to manage fluid flow, then fluid distribution is improved, but solids accumulation and equipment wear increase, and processing efficiency is hindered

Engineering Contradiction:
Improvefluid distributionVSAvoidprocessing efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent removes flow directing trays from the screen deck assembly, extracting the problematic component that caused solids accumulation and wear. The fluid distribution function is achieved through the screen deck geometry and vibration pattern alone, eliminating the need for additional flow directing structures.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The vibration mechanism acts as an intermediary to manage fluid flow and prevent solids accumulation without requiring physical flow directing trays. The vibratory motion mediates between the incoming slurry and the screen surface, maintaining efficient processing.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If more screen decks are stacked to increase separation capacity, then solids removal efficiency improves, but machine size and weight increase

Engineering Contradiction:
Improvesolids removal efficiencyVSAvoidmachine weight
Core Design Contradiction:
ProductivityVSWeight of moving object

Solution Approach 1:

The patent stacks multiple screen decks in a nested configuration where each deck is positioned closely above the other, maximizing the use of vertical space. This nested arrangement allows multiple separation stages within a compact height, increasing solids removal efficiency without proportionally increasing machine weight.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from horizontal expansion to vertical stacking, utilizing the vertical dimension to increase processing capacity. By arranging screen decks in the vertical direction rather than expanding horizontally, the machine achieves higher solids removal efficiency while maintaining a compact footprint and controlling weight increase.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Volume of moving object

If screen decks are positioned closer together to reduce machine height, then compactness is improved, but fluid flow between decks is restricted

Engineering Contradiction:
Improvemachine heightVSAvoidfluid throughput
Core Design Contradiction:
Volume of moving objectVSQuantity of substance

Solution Approach 1:

The patent uses mechanical vibration to maintain adequate fluid flow between closely spaced screen decks. The vibratory motion prevents fluid stagnation and ensures continuous flow through the nested deck arrangement, allowing compact positioning without restricting throughput.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent introduces dynamic vibration to the static fluid flow problem, allowing the system to maintain fluid movement and throughput despite reduced vertical spacing. The dynamic vibratory action compensates for the restricted space between decks, enabling compact design while preserving fluid flow capacity.

Inventive Principle:
Principle #15Dynamics

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 configuration allows for faster and more efficient solids removal from drilling mud, reducing fluid throughput issues and equipment wear, while maintaining a compact design that can handle high volumes of fluid with improved separation efficiency.

Implementation Method 1

vibratory screening machines such as the so called 'shale shakers'

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

the screening surfaces are each inclined from the horizontal to have a lower, feed receiving, end and an upper, solids discharge, end

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3137721B1Screening apparatus and method
Publication Date: 2023.08.16 NAT OILWELL VARCO UK LTD
  • EP3137721B1 patent drawingFigure 1
  • EP3137721B1 patent drawingFigure 2A~2B
  • EP3137721B1 patent drawingFigure 2C~2D

AI summary

A method for separating solids from a drill cuttings and drilling mud mixture feed in a shale shaker includes providing a shale shaker (1) having a basket (4) including a stack of at least two screen decks (8,8a, 8b), wherein the screening surfaces (9,9a, 9b) of the decks are spaced apart and superposed one above the other. A fluid retaining wall (5) and the feed receiving end (12a, 12b) of the screening surface of the lowest screen deck define a pond region (15). In use of the method a drill cuttings and drilling mud mixture feed (18) forms a pond of solids and liquid in the pond region that immerses a portion of the screening surface at the feed receiving end of each of the two screen decks. Apparatus for use in the method is also described.