Thermocouple Replacement Mechanism in Radioactive Measuring Sticks
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Solution Overview
Problem
Existing temperature-measuring sticks face challenges in replacing thermocouples without disassembling the stick, especially in radioactive environments, due to the fragility and rigidity of thermocouples, which are difficult to manipulate using telemanipulator tools with limited handleability.
Innovation Solution
The thermocouple is housed in a flexible cable within a concentric sliding sheath, with a conical interface for easy insertion and a locking mechanism, allowing for secure attachment without risk of damage or deformation, and a spring for maintaining contact at the tip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rigid ceramic sheath is used to protect the thermocouple, then the thermocouple is protected from reducing gases and physical damage, but the thermocouple becomes difficult to replace and manipulate due to its rigidity and length
Solution Approach 1:
The protective structure is divided into two distinct parts: a rigid ceramic sheath for protection and a flexible cable for manipulation. The thermocouple can slide within the flexible cable, separating the protection function from the manipulation function, allowing easy replacement while maintaining protection.
Solution Approach 2:
A flexible cable with a smooth outer surface is introduced as the new protective housing for the thermocouple. This flexible cable allows the thermocouple to be easily manipulated and replaced by telemanipulators while still providing protection during insertion and operation.
2Device complexity
If a smooth cylindrical opening is used in the shell, then the structure is simple, but the thermocouple tip may sink too far or become misaligned during insertion
Solution Approach 1:
A conical insertion opening is provided in the shell instead of a cylindrical opening. The conical shape with a specific angle guides the thermocouple tip during insertion, ensuring proper alignment and preventing the tip from sinking too far, while maintaining structural simplicity.
3Device complexity
If the thermocouple is held in place by friction alone, then the structure is simple, but the thermocouple may become loose or detach during use
Solution Approach 1:
A locking mechanism is introduced that engages with the thermocouple and the shell structure. This locking mechanism provides secure retention of the thermocouple, preventing it from becoming loose or detaching during use, while allowing for easy replacement when needed.
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 convenient and accurate replacement of thermocouples using telemanipulators, ensuring proper contact and measurement, even in confined or hazardous environments, with the flexible sheath facilitating sliding and thermal insulation.
Implementation Method 1
a spring extending between a bearing surface bearing against the cable and a bearing surface bearing against the locking piece. When the thermocouple is fully moved down into the compartment, the length of the cable is sufficient for the tip of the thermocouple to reach the bottom of the tip, and for the cable to exert thereby a compression of the spring; this compression maintains thermocouple contact.
Data Source
AI summary
The invention relates to a thermocouple (17) suspended from a part (26, 27) that can be locked onto a connecting section of the measuring stick, which comprises an opening in the form of a guiding cone (30) for inserting the thermocouple. The thermocouple is contained in a flexible cable (24) that can slide in a sheath (35) of the central compartment (16) which houses the thermocouple (17). A spring (34) can be added to lightly press the end of the thermocouple to the end of the housing thereof.