Semi-Continuous Cryogenic Heat Exchange Alternating Exchangers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cryogenic heat exchangers face operational stoppages due to fouling from condensing constituents in the process fluid, which existing methods fail to address effectively, especially in continuous operations, and maintaining spare equipment is costly and results in significant downtime.
Innovation Solution
A semi-continuous heat exchange method that alternates between two heat exchangers, where a contact liquid with dissolved gases or particles fouls one exchanger, and upon detecting a pressure drop, flow is switched to the standby exchanger, and the fouled exchanger is cleaned by heating or passing a non-reactive gas to remove deposits, allowing for continuous operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single heat exchanger is used for continuous operation, then operational simplicity is maintained, but fouling causes stoppage and loss of productivity
Solution Approach 1:
The system divides the heat exchange function into multiple separate heat exchangers (first heat exchanger and second heat exchanger) that can operate independently. When one heat exchanger becomes fouled, the other can take over, allowing the system to maintain continuous operation without complete stoppage for cleaning.
Solution Approach 2:
The system dynamically switches between heat exchangers based on their operational status. The method monitors pressure drops and fouling conditions, then actively transitions from one heat exchanger to another, creating a dynamic operational mode that adapts to changing conditions and maintains productivity.
2Productivity
If spare heat exchanger equipment is kept for continuous operation, then productivity is maintained, but equipment cost and complexity increase
Solution Approach 1:
The system combines multiple heat exchangers into a single integrated operational unit with shared control and switching mechanisms. Rather than maintaining completely separate standby systems, the heat exchangers are merged into a coordinated system where one operates while the other is cleaned, reducing overall complexity compared to having fully independent spare equipment.
Solution Approach 2:
Both heat exchangers are designed to perform the same heat exchange function, making them universally interchangeable. Either heat exchanger can serve as the active unit or the cleaning unit, providing multi-functionality that reduces the need for specialized spare equipment and simplifies the overall system.
3Reliability
If heat exchanger cleaning is performed by dismantling or manual removal, then fouling is removed, but operational time is lost and complexity increases
Solution Approach 1:
The system performs cleaning operations on one heat exchanger while the other is still operational, preparing the cleaned heat exchanger in advance for immediate takeover. This preliminary cleaning action during operational periods eliminates downtime, as the cleaned unit is ready to switch in without interruption to the overall process.
Solution Approach 2:
The cleaning process is designed to maintain continuous useful action by switching between heat exchangers. While one unit is being cleaned, the other continues to perform heat exchange, ensuring that the useful action of heat exchange never stops. The switching mechanism maintains continuity of the primary function during maintenance operations.
4Reliability
If traditional fouling removal methods are applied to cryogenic heat exchangers, then scale is removed, but continuous operation is disrupted and deposits are not effectively addressed
Solution Approach 1:
The system dynamically manages the transition between heat exchangers based on real-time monitoring of fouling conditions. By detecting pressure drops and operational degradation, the system actively switches to a cleaned heat exchanger, maintaining continuous productivity while addressing fouling issues without disrupting the overall cryogenic process.
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 enables continuous or semi-continuous operation of cryogenic heat exchangers by effectively removing fouling deposits, reducing downtime and maintaining operational efficiency without the need for frequent equipment replacement.
Implementation Method 1
providing contact liquid to a first heat exchanger to cool via heat exchange with a coolant
Implementation Method 2
constituents in the process fluid condensing out of the process fluid and depositing onto the walls of the heat exchanger
Implementation Method 3
removing the foulant from the now standby first heat exchanger by providing heat to the portion of the interior walls of the heat exchanger where the foulant is condensed
Implementation Method 4
passing a non-reactive gas across the portion of the interior walls of the heat exchanger where the foulant is condensed
Data Source
AI summary
A method for semi-continuous operation of a heat exchange process that alternates between two heat exchangers is disclosed. The method comprises, first, providing a contact liquid to a first heat exchanger while the second heat exchanger is on standby. The contact liquid contains a dissolved gas, an entrained gas, or residual small particles that foul the first heat exchanger by condensing or depositing as a foulant onto the first heat exchanger, restricting free flow of the contact liquid. Second, detecting a pressure drop across the first heat exchanger. Third, switching flows of the coolant from the first to the second heat exchanger. Fourth, removing the foulant from the now standby first heat exchanger by providing heat to the heat exchanger, passing a non-reactive gas through the heat exchanger, or a combination thereof. In this manner, the heat exchange process operates semi-continuously.