Apparatus and method for intrachannel defouling of a heat exchanger using induction heaters

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Solution Overview

Problem

Cryogenic heat exchangers face challenges in removing foulants without shutting down the process or coolant sides, as existing methods often require shutting down coolant flow to melt foulants off the walls, which leads to warming of the exchanger.

Innovation Solution

The use of induction heating elements to induce eddy currents in conductive metals within the heat exchanger, allowing foulants to sublime, melt, or combine with the process fluid without interrupting the operation of either side, by strategically positioning induction heating elements around various types of heat exchanger configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional heating methods are used to melt foulants off the heat exchanger walls, then the foulants can be removed, but the coolant flow must be shut down causing the exchanger to warm up

Engineering Contradiction:

Improvefoulant removal capabilityVSAvoidcontinuous operation capability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces conventional thermal heating methods (which require shutting down coolant flow) with induction heating technology. Induction heating uses electromagnetic fields to directly heat the heat exchanger walls through induced eddy currents, allowing foulants to be melted and removed while maintaining continuous coolant and process fluid flow. This substitution of heating mechanism resolves the contradiction by enabling foulant removal without interrupting operation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If the exchanger is shut down to remove foulants, then cleaning can be performed, but productivity is reduced due to downtime

Engineering Contradiction:

Improvefoulant removal capabilityVSAvoidoperational efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent enables continuous operation of the heat exchanger during foulant removal by using induction heating to melt and eliminate deposits while both coolant and process fluid continue to flow. The induction heating system can be activated periodically or continuously to maintain heat transfer surface cleanliness without requiring shutdowns, thereby maintaining uninterrupted productivity while performing the useful action of foulant removal.

Inventive Principle:

Principle #20Continuity of useful action

3Ease of manufacture

If direct heating is applied to tubes/plates to melt foulants, then cleaning is effective, but the exchanger warms up due to loss of coolant flow

Engineering Contradiction:

Improvefoulant removal capabilityVSAvoidexchanger temperature control

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The patent replaces conventional direct heating methods (which require coolant flow shutdown) with induction heating technology. Induction heating uses electromagnetic fields to directly heat the heat exchanger walls through induced eddy currents, allowing foulants to be melted and removed while maintaining continuous coolant and process fluid flow. This substitution of heating mechanism resolves the contradiction by enabling foulant removal without interrupting operation.

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

Enables the removal of foulants from cryogenic heat exchangers without shutting down the process or coolant sides, maintaining operational efficiency and preventing warming of the exchanger, by using induction heating to effectively heat the foulants off the inner surfaces.

Implementation Method 1

The one or more induction heating elements are connected to a source of electrical current. When the electrical current flows through the induction heating elements, eddy currents are induced in the first metal, heating the first metal

Methodology Applied

Scientific EffectEddy currents: Eddy Currents

Implementation Method 2

Induction heaters are used when direct heating is difficult or impossible. Induction heaters can induce eddy currents in a conducting object, typically metals.

Methodology Applied

Scientific EffectInduction heating: Induction Heating

Implementation Method 3

heating the first metal such that the fouling component sublimates, melts, absorbs, or a combination thereof into the circulating process fluid

Methodology Applied

Scientific EffectSublimation: Sublimation

Data Source

PatentUS10539382B2Apparatus and method for intrachannel defouling of a heat exchanger using induction heaters

Publication Date: 2020.01.21 U S BANK TRUST CO NAT ASSOC

AI summary

An apparatus comprising a heat exchanger and one or more induction heating elements is disclosed. The heat exchanger comprises a coolant side conduit and a process side conduit, the process side conduit being susceptible to fouling by at least partial desublimation, condensation, crystallization, deposition, or combinations thereof of a fouling component of a circulating process fluid. An electrically conductive first metal is disposed adjacent to the process side conduit. The one or more induction heating elements are disposed proximate to the heat exchanger. The one or more induction heating elements are connected to a source of electrical current. When the electrical current flows through the induction heating elements, eddy currents are induced in the first metal, heating the first metal such that the fouling component sublimates, melts, absorbs, or a combination thereof into the circulating process fluid.