Underdrain Lateral with Segmented Gas Chambers for Filter Washing

Solution Overview

Problem

Current underdrain systems for filter systems are susceptible to maldistribution of air and water, leading to inefficient washing cycles and reduced filtration efficiency due to limitations in pressure and distribution design, particularly in combined air/water systems.

Innovation Solution

The design of an underdrain lateral with multiple chambers allows for simultaneous liquid and gas washing from one chamber and independent liquid or gas washing from another, with features like primary and secondary gas chambers to manage pressure differences and include pulsating and steady stream gas flow, ensuring uniform distribution across the filter bed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single compartment underdrain is used for combined air/water distribution, then the device complexity is reduced, but the washing efficiency deteriorates due to maldistribution and uncontrolled air/water interface

Engineering Contradiction:

Improveunderdrain structureVSAvoidwashing efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The underdrain is divided into multiple separate compartments (first compartment for air, second compartment for water, third compartment for combined air/water) instead of using a single mixed compartment. This segmentation allows independent control of air and water distribution, eliminating the air/water interface problems and maldistribution issues while maintaining reasonable structural complexity through modular design

Inventive Principle:

Principle #1Segmentation

2Reliability

If air and water are distributed through separate orifices in different compartments, then the distribution control is improved, but the device complexity increases due to multiple compartments and orifices

Engineering Contradiction:

Improvedistribution uniformityVSAvoidunderdrain structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The underdrain is divided into multiple separate compartments (first compartment for air, second compartment for water, third compartment for combined air/water) instead of using a single mixed compartment. This segmentation allows independent control of air and water distribution, eliminating the air/water interface problems and maldistribution issues while maintaining reasonable structural complexity through modular design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The underdrain system is designed to perform multiple functions through its compartments: the first compartment provides air distribution, the second compartment provides water distribution, and the third compartment provides combined air/water distribution. This multi-functionality allows the system to handle various washing requirements (air wash, water wash, combined wash) while using a unified underdrain structure

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of manufacture

If the underdrain uses a shared compartment for air and water, then the manufacturing simplicity is maintained, but the washing quality deteriorates due to uncontrolled air/water interface and pressure limitations

Engineering Contradiction:

Improveunderdrain fabricationVSAvoidwashing fluid distribution

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The underdrain is divided into multiple separate compartments (first compartment for air, second compartment for water, third compartment for combined air/water) instead of using a single mixed compartment. This segmentation allows independent control of air and water distribution, eliminating the air/water interface problems and maldistribution issues while maintaining reasonable structural complexity through modular design

Inventive Principle:

Principle #1Segmentation

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 enhances the washing efficiency by maintaining a stable air/water interface, compensating for velocity head and friction loss, and improving the overall cleaning of the filter bed, thereby extending filtration and washing cycles.

Implementation Method 1

The underdrain directs and receives fluids during operation of various cycles of the filter system including the filtration cycle and a washing cycle

Methodology Applied

Scientific EffectFluid flow:

Implementation Method 2

maintaining a stable air/water interface, compensating for velocity head and friction loss

Methodology Applied

Scientific EffectPressure balance:

Implementation Method 3

include pulsating and steady stream gas flow, ensuring uniform distribution across the filter bed

Methodology Applied

Scientific EffectGas flow:

Data Source

PatentUS8277665B2Method of washing a particulate filter bed using an underdrain

Publication Date: 2012.10.02 RG DELAWARE

AI summary

An apparatus for filtering water and/or wastewater including at least one underdrain lateral having a primary gas chamber and a secondary gas chamber where the secondary gas chamber serves to equalize pressure differences that may occur during the initial distribution due to velocity head changes and friction effects. Preferably, the underdrain lateral includes a plurality of chambers directing a washing fluid into the filter bed where at least one of the plurality of chambers directs a liquid and a gas simultaneously into the filter bed and at least one other chamber of the plurality of chamber directs only one of a liquid and a gas into the filter bed at the same time as that the combination of liquid and gas is directed into the filter bed.