Expandable Tube Plug Sealing for Variable Heat Exchanger Tubes
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Solution Overview
Problem
Conventional cylindrical tube plugs are difficult to position and install in heat exchanger tubes with varying diameters, especially in hard-to-reach locations, leading to damage and inconsistent sealing due to the need for hammering and low pressure sealing capacity.
Innovation Solution
A tube plug with a non-cylindrical body and a deformable wall that expands when a threaded insert member is rotated, allowing for controlled torque installation and secure sealing in tubes of various sizes, using a housing member with a non-cylindrical body and a cylindrical body with a threaded bore, and a ramped ferrule to deform the wall outwardly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional cylindrical tube plug is used, then the plug structure is simple, but it is difficult to position and install in tubes with varying diameters, leading to damage and inconsistent sealing
Solution Approach 1:
The plug transitions from a static cylindrical shape to a dynamic expandable structure. The deformable wall allows the plug to change its outer diameter from a collapsed state during insertion to an expanded state for sealing, enabling adaptation to various tube diameters while maintaining ease of installation through a consistent insertion process
Solution Approach 2:
The plug utilizes parameter changes by varying the outer diameter of the deformable wall through controlled expansion. The ramped ferrule and threaded insert mechanism enable precise control of the expansion parameter, allowing the same plug design to seal tubes of different diameters by adjusting the expansion degree rather than manufacturing different sized plugs
2Adaptability or versatility
If a tapered plug is used to fit different sized tubes, then the plug can accommodate various tube diameters, but the installation process requires hammering that can result in damage to tubes and exchanger components
Solution Approach 1:
The invention replaces the impact-based mechanical insertion method (hammering) with a controlled thread-based mechanical system. The rotating nut and threaded insert provide gradual, controlled expansion of the deformable wall, eliminating the harmful impact forces that cause damage to tubes and surrounding components while maintaining the ability to fit different tube sizes
3Adaptability or versatility
If a tapered plug is used, then the plug can be installed in tubes of various sizes, but the sealing capacity is low and consistent installation criteria cannot be achieved
Solution Approach 1:
The threaded insert mechanism provides inherent feedback control during installation. As the nut rotates and advances the threaded insert, the operator can feel and control the expansion force through the threading engagement, ensuring consistent sealing pressure. The deformable wall's resistance to expansion provides tactile feedback that prevents over-expansion and ensures uniform sealing across different tube sizes
Solution Approach 2:
The dynamic expansion capability allows the plug to adapt its sealing surface area and pressure distribution to match the specific tube diameter. The deformable wall expands uniformly to contact the tube inner surface, creating consistent sealing pressure regardless of the starting tube size, thereby improving both sealing capacity and installation consistency
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 easy sizing and positioning of the plug with consistent torque installation, providing improved sealing capacity and preventing damage to tubes and exchanger components, while accommodating tubes of different sizes with precise force control.
Implementation Method 1
An insert member having a threaded shank corresponding to the threaded bore and a ramped ferrule is positioned to deform the deformable wall of the non-cylindrical body outwardly when the threaded shank is advanced into the threaded bore by rotating the nut
Data Source
AI summary
A tube plug for securely sealing a tube to be plugged. The tube plug has a housing member with a non-cylindrical body and a deformable wall. An insert member having a threaded shank and a ramped ferrule can be threaded into the body to deform the deformable wall outwardly and into engagement with the tube to be sealed. The non-cylindrical body allow the plug to be inserted into and used to plug a tube that is in a difficult to reach location and whose diameter may not be precisely known.