Centrifugal Separator Disc Stack Segmentation

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Solution Overview

Problem

Centrifugal separators have limited throughput capacity, which restricts their efficiency in processing heavy fuel oil and lubrication oil, necessitating an enhancement in certified flow rate (CFR) to improve separation efficiency.

Innovation Solution

A centrifugal separator design featuring a stack of separation discs with a larger diameter disc positioned in the upper part of the stack, increasing the certified flow rate by up to 10%, while minimizing the risk of particle recirculation and maintaining open space for separation, with less than 10 discs of the second type arranged within the upper 25% of the total number.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a single separation disc with a brim extending radially outside is provided to divide the disc stack into purifier and concentrator sections, then the separation efficiency is improved, but the throughput capacity remains limited

Engineering Contradiction:
Improveseparation efficiencyVSAvoidthroughput capacity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The disc stack is segmented into multiple sections with different disc diameters. The upper portion contains discs with larger outer diameter (B) forming a concentrator section, while the lower portion contains discs with smaller outer diameter (A) forming a purifier section. This segmentation allows each section to perform its specific function optimally while increasing overall throughput capacity by up to 10%.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the disc stack are given different local qualities through varying disc diameters. The upper concentrator section uses larger diameter discs optimized for heavy phase cleaning, while the lower purifier section uses smaller diameter discs optimized for light phase cleaning. This local differentiation resolves the contradiction by allowing each region to contribute differently to overall performance.

Inventive Principle:
Principle #3Local quality

2Productivity

If the number of separation discs with larger diameter is increased to increase throughput capacity, then the certified flow rate increases, but the risk of particle recirculation and clogging increases

Engineering Contradiction:
Improvecertified flow rateVSAvoidparticle recirculation risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

Instead of using uniformly large diameter discs throughout the stack, the invention applies large diameter discs partially - specifically in the upper 25% portion of the disc stack. This partial application increases throughput capacity while limiting the number of large discs to less than 10, thereby controlling particle recirculation risk and maintaining reliability.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The invention changes the parameter of disc outer diameter along the axial direction of the stack. By varying the disc diameter parameter from large (B) in the upper section to small (A) in the lower section, the system optimizes both throughput capacity and particle recirculation control through gradual parameter transition.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If separation discs are arranged to form passages between adjacent discs, then the separation function is maintained, but the open space for separation is reduced

Engineering Contradiction:
Improveseparation functionVSAvoidopen space for separation
Core Design Contradiction:
Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The invention optimizes the radial dimension by using discs with different outer diameters arranged axially. This dimensional variation creates additional open space in the radial direction for separation while maintaining the passage formation between adjacent discs in the axial direction, thus preserving separation function while increasing available separation area.

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

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 significantly increases the throughput capacity of the centrifugal separator, enhancing the separation efficiency of heavy fuel oil and lubrication oil by increasing the certified flow rate and minimizing clogging risks.

Implementation Method 1

Centrifugal separators are generally used for separation of liquids and/or for separation of solids from a liquid. During operation, liquid mixture to be separated is introduced into a rotating bowl and heavy particles or denser liquid, usually water, accumulates at the periphery of the rotating bowl whereas less dense liquid accumulates closer to the central axis of rotation.

Methodology Applied
Scientific EffectCentrifugal separation: Centrifugal Separation

Data Source

PatentEP3085450B1Centrifugal separator with disc stack
Publication Date: 2020.02.26 ALFA LAVAL CORP AB
  • EP3085450B1 patent drawingFigure 1a~1c
  • EP3085450B1 patent drawingFigure 2
  • EP3085450B1 patent drawingFigure 3a~3d

AI summary

The present invention provides a centrifugal separator comprising a frame, a drive member configured to rotate a rotating part in relation to the frame around an axis of rotation (x), wherein the rotating part comprises a centrifuge rotor enclosing a separation chamber. The separation chamber comprises a stack of separation discs arranged coaxially around the axis of rotation (X) at a distance from each other such as to form passages between each two adjacent separation discs. The stack of separation discs comprises a first type of separation discs having an outer diameter of A or below, and at least one separation disc of a second type having outer diameter B or above, wherein diameter B is larger than diameter A. At least one of the separation discs of the second type is arranged at a position in the disc stack that is within the upper 15 % of the total number of separation discs and at least one of said first type of separation disc is arranged axially above the uppermost separation disc of the second type.