Point of Use Filtration with Backwash

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Solution Overview

Problem

Existing water filtration systems face issues with membrane fouling, require electrical power for backwashing, and generate significant waste water, leading to inefficiencies and safety concerns due to bacterial growth in storage tanks.

Innovation Solution

A system using a single pressurized accumulator tank that simultaneously provides backwash fluid and ultrapure water, employing mechanical pressure switches to automate backwashing without electricity, and incorporating ultrafiltration and microfiltration elements to ensure safe drinking water by removing viruses before storage and bacteria after filtration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional filtration systems use alternative flush liquid or feed water for backwashing, then membrane fouling is reduced, but water waste increases and operational complexity increases

Engineering Contradiction:
Improvemembrane fouling reductionVSAvoidwater waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent makes the filtered water serve multiple functions: it is used both for drinking purposes and for backwashing the ultrafiltration membrane. This eliminates the need for separate flush liquid while reducing water waste compared to conventional systems that discard filtered water.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own produced filtered water to perform the backwashing function, making the system self-sufficient. The filtered water automatically serves to clean the membrane without requiring external flush liquid or additional water sources.

Inventive Principle:
Principle #25Self-service

2Productivity

If conventional systems use tanks to store ultra-filtered water, then water availability is improved, but bacterial growth occurs and system complexity increases

Engineering Contradiction:
Improvewater availabilityVSAvoidbacterial growth
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies a second filtration element (microfiltration) downstream of the storage tank to remove bacteria that may have grown during storage. This preliminary cleaning action ensures that water dispensed to users is free from bacteria regardless of storage duration.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system discards the potentially contaminated stored water through the second filtration element and recovers clean water for dispensing. This eliminates bacterial contamination while maintaining water availability.

Inventive Principle:
Principle #34Discarding and recovering

3Reliability

If conventional backwash systems use electronically controlled valves or pressurized gas, then backwashing effectiveness is improved, but power consumption increases

Engineering Contradiction:
Improvebackwashing effectivenessVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent uses hydraulic pressure from the stored filtered water itself to drive the backwashing process through mechanically actuated valves. This eliminates the need for electrical power or pressurized gas systems while maintaining effective backwashing through water pressure alone.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent replaces electronically controlled valves with mechanically actuated valves that open and close based on pressure differential. This mechanical substitution eliminates power consumption while maintaining valve control functionality for backwashing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If conventional systems use multiple accumulator tanks, then water quality control is improved, but manufacturing cost and system complexity increase

Engineering Contradiction:
Improvewater quality controlVSAvoidnumber of tanks
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the storage function and filtration function into a single integrated system. The first filtration element, storage tank, and second filtration element work together as one unit, eliminating the need for separate accumulator tanks while maintaining water quality control through the dual-filtration approach.

Inventive Principle:
Principle #5Merging (Combining)

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 system effectively reduces waste water generation, provides biologically safe drinking water, and operates without electrical power, making it suitable for areas with unreliable power supplies while maintaining high water quality.

Implementation Method 1

a first filtration element, such as an ultrafiltration element, positioned downstream from the feed water line to remove viruses from the feed water

Methodology Applied
Scientific EffectUltrafiltration: Semipermeable Membrane

Implementation Method 2

a second filtration element, such as a microfiltration element, positioned downstream from the storage tank to remove bacteria from water flowing out of the storage tank

Methodology Applied
Scientific EffectMicrofiltration: Semipermeable Membrane

Implementation Method 3

water flows across a membrane from a feed side to a permeate side in response to a pressure differential between the feed side and the permeate side

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 4

Many water filtration systems have a backwash cycle to backwash the upstream side of the filtration membrane to remove any of the accumulated reject materials from the feed water

Methodology Applied
Scientific EffectBackwash:

Data Source

PatentEP2964368B1Point of use filtration system with backwash
Publication Date: 2020.12.23 PENTAIR RESIDENTIAL FILTRATION LLC
  • EP2964368B1 patent drawingFigure 1~2

AI summary

A system and method for a point of use filtration system with backwash is provided. The system includes a first filtration element, a tank, and a second filtration element positioned downstream from the tank. A first and second valve are each positioned downstream from the first filtration element. A first control line is coupled to a first control switch or a first permeate line and the first valve, and a second control line is coupled to the second control switch or a second permeate line and the second valve.