Regenerative Exhaust Air Separation with Stream Segmentation

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Solution Overview

Problem

Conventional methods for separating organic solvents from process exhaust air in industrial settings, such as painting plants, face inefficiencies due to insufficient solvent desorption at lower filter temperatures, leading to reduced solvent concentration and cleaning device efficiency.

Innovation Solution

A regenerative separation method that divides the regeneration stream into two partial streams, with the first partial stream having a lower impurity concentration returned to the filter for reprocessing and the second partial stream with higher impurity concentration directed to a cleaning device, allowing for increased up-concentration factors and improved efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If the filter temperature is kept low during regeneration, then energy consumption is reduced, but solvent desorption efficiency deteriorates

Engineering Contradiction:

Improveenergy consumptionVSAvoidsolvent desorption efficiency

Core Design Contradiction:

Use of energy by stationary objectVSProductivity

Solution Approach 1:

The regeneration stream is divided into two partial streams: a first partial stream with lower impurity concentration that is returned to the filter for reprocessing, and a second partial stream with higher impurity concentration directed to the cleaning device. This segmentation allows the system to maintain lower overall energy consumption while still achieving sufficient solvent desorption by concentrating the最难脱附的solvents in the second partial stream for targeted cleaning.

Inventive Principle:

Principle #1Segmentation

2Speed

If the flow rate of regeneration air is increased, then the regeneration speed is improved, but the solvent concentration in the concentrate air is reduced

Engineering Contradiction:

Improveregeneration speedVSAvoidsolvent concentration

Core Design Contradiction:

SpeedVSQuantity of substance

Solution Approach 1:

By splitting the regeneration stream into two partial streams with different flow rates and concentrations, the system can use a higher total flow rate for rapid regeneration while concentrating the solvent-rich portion in the second partial stream. This allows fast regeneration speed to be maintained without sacrificing the solvent concentration needed for efficient cleaning.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system changes the concentration parameter of the regeneration stream by dividing it into two partial streams with different impurity concentrations. The first partial stream has lower concentration and is recycled, while the second partial stream has higher concentration and is sent to cleaning, thus optimizing both regeneration speed and solvent concentration.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If a single-stage filtering system is used, then device complexity is reduced, but up-concentration factor is limited

Engineering Contradiction:

Improvesystem structureVSAvoidup-concentration factor

Core Design Contradiction:

Device complexityVSQuantity of substance

Solution Approach 1:

The system segments the regeneration stream into two partial streams with different impurity concentrations, creating a functional differentiation within a single filtering device. This allows the system to achieve high up-concentration factors (2:1 to 20:1 or higher) without requiring multiple filtering stages, thus maintaining relatively simple device structure while significantly improving concentration capability.

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 method achieves higher up-concentration factors, typically up to 40:1, enhancing the efficiency of the cleaning device and enabling auto-thermal operation, while optimizing energy demand and reducing the impurity concentration in process exhaust air to meet environmental standards.

Implementation Method 1

the volatile organic solvents are physically attached (adsorption, absorption) to a separation unit, in particular a filter of a separating device

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 2

This process can be reversed (desorption) by increasing the temperature of the filter

Methodology Applied

Scientific EffectDesorption: Desorption

Implementation Method 3

For the desorption process, for example, hot air of 140 to 450° C. having a low flow rate is used

Methodology Applied

Scientific EffectThermal energy transfer: Conduction (thermal)

Data Source

PatentUS10682604B2Method and regenerative separating apparatus for separating contaminants from process exhaust air

Publication Date: 2020.06.16 DUERR SYST AG

AI summary

A method for separating impurities from process exhaust air is provided and includes the steps of passing a process exhaust air through a separating device comprising a separation unit, regenerating the separating device by passing a regeneration stream therethrough, where outer lateral surfaces of the separation unit are continuously loaded by the process exhaust air and the regeneration stream, dividing the regeneration stream passing through the separating device during regeneration into a first partial stream having an impurity concentration less than a first predetermined limit, and a second partial stream having an impurity concentration equal to or greater than a second predetermined limit, where the second predetermined limit is equal to or greater than the first predetermined limit, returning the first partial stream generated during regeneration to the separating device and directing the second partial stream generated during regeneration to a cleaning device.