Sub-atmospheric Gas Scrubber with Recirculating Solvent System

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Solution Overview

Problem

Existing gas scrubbers for vacuum systems are inefficient in removing contaminants, leading to pump jamming, premature wear, and high energy consumption, with known scrubbers consuming excessive solvent and requiring large apparatus that is costly and impractical for indoor installations.

Innovation Solution

A sub-atmospheric pressure gas scrubber with a recirculating solvent system that maintains a constant solvent level and vacuum pressure, using a centrifugal recirculating pump and gravity drain with a siphon control system, along with a heat exchanger to regulate solvent temperature, and multiple spray nozzles for effective contaminant removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a known gas scrubber uses a large volume of cleaning solvent to remove contaminants, then contaminant removal effectiveness is improved, but solvent consumption increases and operating cost increases

Engineering Contradiction:
Improvecontaminant removal effectivenessVSAvoidsolvent consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent implements a solvent recovery system where used cleaning solvent is collected from the bottom of the vessel and reused. The solvent outlet at the bottom allows continuous removal of contaminated solvent while fresh solvent is introduced at the top, creating a circulation system that reduces overall solvent consumption while maintaining effective contaminant removal capability

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The patent changes the physical parameters of solvent distribution by introducing solvent at the top of the vessel and collecting it at the bottom, creating a countercurrent flow pattern. This parameter change optimizes the interaction between cleaning solvent and process gas, improving contaminant removal efficiency while reducing the total volume of solvent required

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a known gas scrubber uses a large vessel volume to ensure uniform gas scrubbing, then gas cleaning effectiveness is improved, but device size increases and installation complexity increases

Engineering Contradiction:
Improvegas cleaning effectivenessVSAvoidvessel volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent segments the gas cleaning process into distinct zones within the vessel: a spray zone at the top where cleaning solvent is introduced, a mixing zone in the middle where gas and solvent interact, and a separation zone at the bottom where cleaned gas exits and contaminated solvent collects. This segmentation allows efficient gas cleaning in a more compact vessel configuration

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent utilizes vertical dimensionality by introducing solvent at the top and collecting it at the bottom, creating a countercurrent flow pattern that maximizes the use of vertical space. This dimensional approach allows effective gas-solvent interaction without requiring excessive horizontal vessel volume, making the system more compact for indoor installation

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

3Reliability

If a heating jacket is provided to prevent contaminant solidification, then pump reliability is improved, but energy consumption increases and system complexity increases

Engineering Contradiction:
Improvepump operabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent converts the harmful effect of contaminant condensation into a beneficial cleaning mechanism. Instead of using heat to prevent condensation, the system allows contaminants to condense on cold surfaces and be removed by the countercurrent solvent flow, transforming a potential problem into an effective contaminant removal mechanism while avoiding energy-intensive heating

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent replaces the thermal field approach (heating jacket) with a mechanical field approach (countercurrent solvent flow system). Instead of using thermal energy to prevent contaminant solidification, the system uses mechanical solvent circulation to physically remove contaminants before they can cause pump failure, reducing energy consumption while maintaining reliability

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

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 contaminant buildup, minimizes solvent consumption, and maintains vacuum pressure, making it more efficient and compact, thus reducing operational costs and installation constraints.

Implementation Method 1

The solvent interacts with the contaminants in the process gas to remove them

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

the act of compressing the gas being pumped causes heating of the gas, which heat is transferred to the rotors and stators of the pumps... contaminants within the gas being pumped will not condense on the rotors and stators

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

a recirculating pump that recirculates the cleaning solvent from the cleaning solvent outlet back to the cleaning solvent inlet

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 4

means for maintaining a desired level of cleaning solvent in the vessel whilst maintaining the vacuum pressure in the vessel above the said level of solvent

Methodology Applied
Scientific EffectSiphon effect: Syphon

Implementation Method 5

a recirculating pump that recirculates the cleaning solvent from the cleaning solvent outlet back to the cleaning solvent inlet

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 6

a heat exchanger to regulate solvent temperature

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 7

using a centrifugal recirculating pump

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2734286B1Sub-atmospheric pressure gas scrubbers
Publication Date: 2018.05.16 EDWARDS LTD
  • EP2734286B1 patent drawingFigure 1
  • EP2734286B1 patent drawingFigure 2~2A
  • EP2734286B1 patent drawingFigure 3

AI summary

In order to minimise the amount of contaminants that pass through a pump, or that are allowed to accumulate therein, a sub-atmospheric pressure gas scrubber suitable for use upstream of a vacuum pump is provided. The gas scrubber comprising a vessel and means for forming a spray of cleaning solvent within the vessel, the vessel comprising an inlet and an outlet for the gas to be cleaned at sub atmospheric pressure, the inlet and outlet being arranged to cause the gas to be cleaned to pass through the spray of cleaning solvent, the means for forming a spray comprising a cleaning solvent inlet connected to at least one spray nozzle and a cleaning solvent outlet through which used solvent can be pumped from the vessel using a pump, wherein the pump is arranged to recirculate the used solvent back to the cleaning solvent inlet.