Hydropneumatic Pressure Storage for Filter Backwash Flow Stability

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Solution Overview

Problem

Existing filter devices face challenges in maintaining trouble-free operation, particularly in compensating for pressure fluctuations and avoiding flow losses during filtration and backflushing processes, which can lead to inconsistent volume flow and reduced efficiency.

Innovation Solution

A filter device with a hydropneumatic pressure storage device featuring a movable separating element that divides the pressure storage into a working chamber and a pressure chamber, connected to a compressed air source, allowing for pressure control and volume compensation, thereby stabilizing the pressure level and maintaining consistent volume flow during filtration and backflushing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a backwash line drains backwash quantity during backwash processes, then the backwashing intensity is increased, but the volume flow of the filtrate decreases due to bypass flow

Engineering Contradiction:
Improvebackwashing intensityVSAvoidvolume flow of filtrate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

A storage device is introduced as an intermediary between the filter housing and the backwash line. This storage device temporarily holds the backwash quantity, allowing the backwash process to proceed with sufficient flow rate while preventing the bypass flow from directly reducing the filtrate volume flow to the consumer.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The storage device is pre-filled with a predetermined volume of fluid before the backwash process starts. This preliminary action ensures that when the backwash valve opens, the backwash quantity can be drained without immediately affecting the filtrate supply, as the storage device's pre-stored fluid compensates for the temporary bypass flow.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a pressure accumulator with spring-loaded separating element is used, then backwashing can be supported, but the device becomes large and complex with numerous valves, springs and magnets

Engineering Contradiction:
Improvebackwashing supportVSAvoidnumber of valves, springs and magnets
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The complex elements (springs, magnets, multiple valves) traditionally required for pressure accumulation and backwash control are extracted and replaced by a simpler storage device concept. The storage device requires only a single valve for controlling the backwash quantity drainage, significantly reducing device complexity while maintaining the ability to support backwashing.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the operational parameters of the storage device, specifically controlling the drainage rate of the backwash quantity to a predetermined value. This parameter control allows the system to achieve reliable backwashing support without requiring complex mechanical elements like springs and magnets, simplifying the overall device structure.

Inventive Principle:
Principle #35Parameter changes

3Stress or pressure

If compressed air is supplied to the working chamber during backwash, then pressure level is maintained, but additional control complexity is introduced

Engineering Contradiction:
Improvepressure level on clean sideVSAvoidvalve device control
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

Compressed air is supplied continuously or periodically to the working chamber of the storage device during backwash operations. This continuous action maintains the pressure level on the clean side of the filter housing throughout the backwash process, ensuring that the filter elements remain properly supported and that filtrate supply to consumers is not interrupted, despite the simplified single-valve control mechanism.

Inventive Principle:
Principle #20Continuity of useful 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

The solution ensures a compact design with no flow losses, maintains consistent volume flow, and supports filtration and backflushing processes by compensating for pressure fluctuations and volume changes, enhancing the overall operational efficiency and reliability of the filter device.

Implementation Method 1

on the clean side of the respective filter housing there is at least one storage device in the form of a hydropneumatic pressure storage device

Methodology Applied
Scientific EffectHydropneumatic pressure storage: Hydraulic Accumulator

Implementation Method 2

of which the working space can be connected to a compressed air source

Methodology Applied
Scientific EffectCompressed air storage: Accumulator (energy)

Implementation Method 3

with at least one movable separating element that divides the pressure storage device into a working chamber and a pressure chamber

Methodology Applied
Scientific EffectPiston movement: Displacement

Implementation Method 4

at least one filter element being backwashed by means of a backwashing device to clean its effective filter surface

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 5

Backwash device in the backwash line connected to the raw side of the filter element to be backwashed Has a backwash valve which can be opened for backwash processes

Methodology Applied
Scientific EffectValve control: Valve

Data Source

PatentEP2651529B1Filter device
Publication Date: 2018.10.03 HYDAC PROCESS TECH
  • EP2651529B1 patent drawingFigure 1
  • EP2651529B1 patent drawingFigure 2

AI summary

The invention relates to a filter device comprising at least one filter housing (1) in which at least one filter element (21) is arranged. Inside the filter housing (1), the filter element separates a clean side (9) from an untreated side (13). The device is characterised in that, on the clean side (9) of the respective filter housing (1) at least one storage unit (3) having at least one movable separating element (47) is connected, which divides the storage unit (3) into two working chambers (49) or pressure chambers (43).