Annular Filter Assembly With Offset Passages for Efficient Backwashing

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Solution Overview

Problem

Existing filtering units, particularly those used in water-based applications, face inefficiencies in backwashing due to insufficient pressure gradients, leading to incomplete mesh cleaning without the need for increasing overall flow rates, which would require oversized upstream equipment.

Innovation Solution

The design incorporates annular filtering components with circumferentially distributed ribs forming sectors, offset passages, and a keying mechanism to ensure proper assembly and sequential backwashing, enhancing backflush flow efficiency without increasing overall flow or sector count.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pressure gradient is increased to ensure complete backwashing of the filtering mesh, then backwashing efficiency is improved, but the overall flow rate increases causing loss of cleaned flow and requiring oversized upstream equipment

Engineering Contradiction:
Improvebackwashing efficiencyVSAvoidcleaned flow
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The filter is divided into multiple independent sectors separated by radial ribs, allowing selective backwashing of individual sectors. This segmentation enables the backwashing flow to be concentrated on specific sectors rather than distributed across the entire filter surface, achieving effective mesh cleaning without increasing the overall flow rate through the filter.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies local quality by creating sectors with different functional characteristics. Each sector can be independently backwashed when needed, while other sectors continue normal filtration. The radial ribs create localized compartments that allow targeted application of backwashing flow to specific areas with filtering mesh, improving backwashing efficiency without affecting the entire filter system.

Inventive Principle:
Principle #3Local quality

2Reliability

If the number of sectors is increased to improve fluid distribution homogeneity, then backwashing efficiency is improved, but the device complexity and pressure losses increase

Engineering Contradiction:
Improvefluid distribution homogeneityVSAvoidsector count
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The filter is divided into multiple independent sectors separated by radial ribs, allowing selective backwashing of individual sectors. This segmentation enables the backwashing flow to be concentrated on specific sectors rather than distributed across the entire filter surface, achieving effective mesh cleaning without increasing the overall flow rate through the filter.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a radial dimension to the filter structure with ribs extending from the center to the periphery, creating sectors in the radial-circumferential plane. This dimensional approach allows fluid distribution to be controlled radially through distribution columns, achieving homogeneous distribution without requiring an excessive number of sectors that would increase complexity.

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

3Reliability

If the number of sectors is increased to improve backwashing coverage, then backwashing efficiency is improved, but pressure losses and device complexity increase

Engineering Contradiction:
Improvebackwashing coverageVSAvoidpressure losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The filter is divided into multiple independent sectors separated by radial ribs, allowing selective backwashing of individual sectors. This segmentation enables the backwashing flow to be concentrated on specific sectors rather than distributed across the entire filter surface, achieving effective mesh cleaning without increasing the overall flow rate through the filter.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies partial action by backwashing only the specific sectors that require cleaning, rather than backwashing the entire filter simultaneously. The rotary distributor can selectively direct backwashing flow to individual sectors as needed, achieving adequate backwashing coverage for soiled areas without the pressure losses associated with system-wide backwashing.

Inventive Principle:
Principle #16Partial or excessive action

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 improves backwashing efficiency by ensuring homogeneous fluid distribution and reducing pressure losses, maintaining effective filtering performance while avoiding the need for oversized equipment.

Implementation Method 1

a filtering component for a filtering unit with backwashing, the filtering component being annular and comprising an inner edge, an outer edge and a filtering medium extending between the inner edge and the outer edge

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 2

the pressure gradient across the filtering mesh, i.e. the pressure gradient between the external face side and the internal face side

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP4088799B1Filtering component for a filtering unit with backwashing
Publication Date: 2026.01.28 ALFA LAVAL MOATTI SNC
  • EP4088799B1 patent drawingFigure 1~2
  • EP4088799B1 patent drawingFigure 3
  • EP4088799B1 patent drawingFigure 4~5

AI summary

A filtering component (10) for a filtering unit (90) with backwashing, the filtering component (10) being annular and comprising a filtering medium (22) between an inner edge (24) and an outer edge (26), and an internal face (20) and an external face (21) on either side of the filtering medium (22). The filtering component (10) is adapted to be assembled against a first identical filtering component (10') so that their facing respective internal faces (20, 20') define a space that is circumferentially compartmented by contacting respective ribs (28, 28'). One of the inner edge (24) and the outer edge (26) has passages (30) communicating with each of the sectors on the internal face (20). The external face (21) has a key (36) for pairing the filtering component (10) in a given position with respect to a second identical filtering component (10"), such that the passages (30") of the second identical filtering component (10") are offset with respect to the passages (30) of the filtering component (10).