Heat Exchanger Closure Assembly for Fast Locking and Thermal Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat exchanger closure assemblies face challenges with handling and installation, particularly under varying thermal and pressure loads, leading to potential leaks and increased maintenance time due to the complexity and weight of the lock ring assembly, which often requires specialized equipment and can result in thread deformation and gasket unloading.
Innovation Solution
A closure assembly for shell-and-tube heat exchangers that uses a lock ring secured with interlocking hubs, allowing for a single linear motion insertion and rotation of less than one turn to lock, eliminating the need for specialized jigs and reducing the risk of jamming, with an elastic torsion member to accommodate thermal expansion and maintain sealing without adjustment of compression bolts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional screw plug closure with multiple threads is used to secure the lock ring, then the closure can maintain sealing under pressure, but the installation requires multiple rotations (20 or more turns) and specialized handling equipment, increasing complexity and time
Solution Approach 1:
The locking mechanism is segmented into discrete hub sections (e.g., 8 sections) around the circumference. Each hub section engages with a corresponding section on the mating component, distributing the locking function across multiple localized points rather than requiring continuous threading around the entire circumference. This segmentation enables rapid engagement with minimal rotation while maintaining secure locking.
Solution Approach 2:
The locking mechanism transitions from a linear threading approach (rotational motion along the axis) to a radial hub engagement approach. The hubs are arranged circumferentially around the closure plug, allowing engagement to occur in a different dimensional configuration. This enables the lock ring to be secured with less than one full rotation by engaging hubs that are distributed around the circumference rather than requiring sequential threading along the length.
2Strength
If a rigid closure assembly is used to contain internal pressure, then pressure containment is improved, but thermal expansion causes plastic deformation of internals and gasket unloading, leading to leakage
Solution Approach 1:
The closure assembly incorporates dynamic elements that allow controlled movement and deformation in response to thermal expansion. Rather than being completely rigid, the assembly can accommodate dimensional changes through elastic deformation of components and adjustment of gasket compression, maintaining sealing reliability while containing pressure. This dynamic behavior prevents plastic deformation and gasket unloading that would occur in a purely rigid system.
3Strength
If the lock ring assembly is made heavy duty to handle high pressure operations, then pressure containment is improved, but the weight requires specialized jigs and equipment for installation, increasing device complexity
Solution Approach 1:
The hub engagement mechanism distributes the weight and locking forces across multiple circumferential contact points (the hubs). This distribution reduces the localized stress and moment arms that would require specialized counterbalancing equipment. The multi-point hub engagement effectively counteracts the gravitational and operational loads on the heavy-duty lock ring, allowing standard handling equipment to suffice while maintaining high pressure containment capability.
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 solution simplifies the installation and removal of the closure assembly, reduces the risk of leaks and thread damage, and allows for faster maintenance operations while maintaining a seal under varying thermal and pressure conditions, eliminating the need for internal flanges and specialized equipment.
Implementation Method 1
an elastic torsion member to accommodate thermal expansion and maintain sealing without adjustment of compression bolts
Implementation Method 2
Expected thermal loads are changes in temperature over time which can occur during initial start up or following repairs, or in the event of an upset or plant trip, any of which singular event can result in a differential thermal expansion of the internal components relative to the channel
Data Source
AI summary
A heat exchanger assembly including an elongated tubular heat exchanger enclosure defining an interior chamber. A tube sheet is positioned within the interior chamber of the heat exchanger enclosure separating the interior chamber into a shell side and a channel side. The interior portion is configured to removably receive a tube bundle positioned within the shell side of the interior chamber. An annular sleeve member is positioned within the channel side of the interior chamber of the heat exchanger enclosure. An annular elastic torsion member is positioned within the channel side of the interior chamber of the heat exchanger such that the sleeve member is positioned between the tube sheet and the elastic torsion member. The elastic torsion member has an inner circumference deflectable relative to its outer circumference for torsioning the elastic torsion member.