High-Strength Tube Sheet Welding for Reduced-Pitch EO Reactors
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Solution Overview
Problem
The fabrication of large ethylene oxide (EO) reactors is becoming increasingly challenging due to their growing size and rising costs, with current welding configurations and materials failing to effectively reduce tube pitch, a critical factor in minimizing reactor size.
Innovation Solution
The use of high tensile strength welding materials with a strength greater than 600 MPa allows for a smaller welding groove and reduced tube pitch, enabling more elongated tubes to be packed into a reactor, thus enabling the construction of a smaller reactor design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If conventional welding materials and configurations are used, then welding structural integrity is maintained, but tube pitch cannot be reduced and reactor size remains large
Solution Approach 1:
The patent changes the material parameter of the welding material, specifically using a high tensile strength welding material (greater than 600 MPa) instead of conventional welding materials. This parameter change enables the use of a smaller welding groove while maintaining adequate welding joint strength, which in turn allows for reduced tube pitch and smaller reactor size.
2Volume of stationary object
If welding groove size is reduced to enable smaller tube pitch, then reactor size is reduced, but welding joint reliability may be compromised
Solution Approach 1:
The patent changes the material parameter of the welding material to high tensile strength (greater than 600 MPa), which compensates for the reduced welding groove size. This parameter change ensures that even with a smaller groove, the welding joint maintains adequate reliability and strength.
Solution Approach 2:
The patent employs a composite approach by combining the high tensile strength welding material with a specifically designed small welding groove configuration. This composite solution of material and geometry enables reduced tube pitch while maintaining welding joint reliability.
3Volume of stationary object
If more tubes are packed into the reactor to reduce size, then reactor volume is reduced, but fabrication complexity increases
Solution Approach 1:
The patent changes the welding material parameter to high tensile strength, which enables the use of a smaller welding groove. This parameter change simplifies the fabrication process for reduced tube pitch configurations, as the smaller groove is easier to prepare and weld compared to traditional groove sizes, thereby reducing fabrication complexity while allowing more tubes to be packed.
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 approach allows for a 7% to 14% increase in the number of tubes within the reactor, leading to a more compact reactor design while maintaining structural integrity, thereby reducing manufacturing costs and complexity.
Implementation Method 1
A welding material is located inside the welding groove and is affixed to the outermost sidewall of the elongated tube passing through the third opening
Data Source
AI summary
Reduced tube pitch within a shell-and-tube heat exchange reactor such as, for example, an EO reactor, is provided by utilizing a welding material that has a high tensile (i.e., a tensile strength of greater than 600 MPa). Reduced tube pitch allows for more elongated tubes (the tubes are filled with a catalyst) to be present in a reactor, and thus a smaller reactor can be manufactured. Notably, the use of a high tensile strength welding material allows the implementation of a small welding groove located between a beveled sidewall of a beveled upper portion of an opening provided in a tube sheet overlay material (that is located atop a tube sheet) and an outermost sidewall of the elongated tube passing through the opening in the tube sheet overlay material.