Reactor Vessel Nozzle Mounting via Symmetrical Flange Insertion
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Solution Overview
Problem
The complex three-dimensional shape of reactor vessel nozzles and the high-radiation underwater environment make manual welding difficult, leading to challenges in nozzle mounting and repair.
Innovation Solution
A nozzle mounting structure that involves removing a symmetrical concave portion from the reactor vessel, inserting a flange with a matching shape, and welding it to the vessel, allowing for easier positioning and welding around a normal line or centerline, without the need for buttered welding or heat treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If buttered welding is performed on the complicated three-dimensional shape of the existing weld part, then the nozzle can be mounted on the reactor vessel, but the welding operation becomes extremely difficult and time-consuming
Solution Approach 1:
The patent applies preliminary action by pre-forming a concave portion in the reactor vessel wall before nozzle installation. This concave portion is created in advance to match the flange shape, eliminating the need for complex buttered welding during installation. The preparatory removal of material simplifies the subsequent welding operation to a straightforward flange-to-vessel connection.
Solution Approach 2:
The patent segments the nozzle structure by separating the flange portion from the main nozzle body. The flange is designed as a distinct component that fits into the pre-formed concave portion, allowing it to be manufactured and positioned separately. This segmentation transforms a complex integrated welding problem into simpler assembly and welding steps.
2Reliability
If manual welding operations are performed in the high-radiation underwater environment, then the nozzle can be welded to the reactor vessel, but the operation becomes unsafe and impractical
Solution Approach 1:
The patent applies self-service by designing the flange with positioning features that automatically align with the concave portion geometry. The flange's outer peripheral surface fits against the inner peripheral surface of the concave portion, enabling self-positioning and self-alignment during installation. This eliminates the need for complex manual positioning operations in the hazardous environment.
3Manufacturing precision
If the flange is positioned accurately in the concave portion, then welding precision is improved, but the positioning mechanism becomes more complex
Solution Approach 1:
The patent applies equipotentiality by creating a geometric match between the flange outer peripheral surface and the concave portion inner peripheral surface. Both surfaces are designed with the same curvature and dimensional characteristics, creating a natural fit that ensures accurate positioning without additional complex positioning mechanisms. The geometry itself provides the positioning function.
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
Facilitates the easy mounting of nozzles by ensuring accurate positioning and welding, reducing operation processes and enabling construction in challenging environments like underwater settings without manual intervention.
Implementation Method 1
a weld part provided around the normal line for welding the flange to the reactor vessel
Data Source
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AI summary
To facilitate mounting of a nozzle, is provided a nozzle mounting structure for mounting a nozzle (20) penetrating through a reactor vessel (10) having a hemispherical concave inner surface, the nozzle mounting structure includes a removed concave portion (17) in which a base material (12) on an inner surface side of the reactor vessel (10) is removed in a symmetrical shape around a normal line (N) on the hemispherical concave inner surface of the reactor vessel (10), a flange (25) provided on the nozzle (20), formed in a same symmetrical shape as that of the removed concave portion (17) around the normal line (N), and inserted into the removed concave portion (17), and a weld part (18) provided around the normal line (N) for welding the flange (25) to the reactor vessel (10).