Reverse Pulley Wire Saw Cutting for Sealed Containment Walls

Solution Overview

Problem

The challenge is to develop a structure reverse-cutting apparatus that can perforate two holes in a containment building wall and then cut the wall from the outside inward using a wire saw, while preventing radiation leakage from the building's interior.

Innovation Solution

The apparatus employs a pair of reverse pulley devices with main tubes inserted through the holes, first and second support pulleys to manage the wire, and cap covers to seal the tubes, allowing the wire saw to cut inwardly without exposing the interior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the wire saw is pulled from inside to outside through two holes in the containment building wall, then the cutting task can be performed, but radiation will leak from the interior of the containment building

Engineering Contradiction:

Improvecutting task feasibilityVSAvoidradiation leakage

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent inverts the conventional cutting direction by pulling the wire saw from outside to inside through the holes, rather than from inside to outside. This reversal allows the cutting to proceed while maintaining radiation containment, as the wire and pulley system is configured to operate with the wire entering from the outside and being pulled inward through sealed openings.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces intermediary components including pulleys mounted on rods that extend through the holes, and a sealing structure with a flexible membrane that covers the holes. These intermediaries transfer the cutting force while maintaining radiation containment, allowing the wire saw to cut from outside to inside without direct exposure between the interior and exterior.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If the wire saw is pulled from outside to inside through two holes in the containment building wall, then radiation leakage is prevented, but the cutting direction is reversed from conventional practice

Engineering Contradiction:

Improveradiation containmentVSAvoidcutting operation complexity

Core Design Contradiction:

Object-generated harmful factorsVSEase of operation

Solution Approach 1:

The patent inverts the conventional cutting direction by pulling the wire saw from outside to inside through the holes, rather than from inside to outside. This reversal allows the cutting to proceed while maintaining radiation containment, as the wire and pulley system is configured to operate with the wire entering from the outside and being pulled inward through sealed openings.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent divides the cutting system into separate functional components: a wire supplier unit outside the building, pulleys mounted on rods extending through the holes, and a sealing structure. This segmentation allows each component to be optimized for its specific function while working together to achieve reverse cutting with radiation containment.

Inventive Principle:

Principle #1Segmentation

3Ease of operation

If pulleys are mounted inside the containment building to support the wire, then the wire can be supported, but radiation may leak through the mounting openings

Engineering Contradiction:

Improvewire support capabilityVSAvoidradiation leakage through openings

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent introduces intermediary components including pulleys mounted on rods that extend through the holes, and a sealing structure with a flexible membrane that covers the holes. These intermediaries transfer the cutting force while maintaining radiation containment, allowing the wire saw to cut from outside to inside without direct exposure between the interior and exterior.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a flexible membrane or thin film as part of the sealing structure that covers the holes where rods extend. This flexible barrier allows the rods to pass through and support the pulleys while maintaining radiation containment, as the membrane can deform with rod movement while blocking radiation passage.

Inventive Principle:

Principle #30Flexible shells and thin films

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 effectively prevents radiation leakage by allowing the wire saw to cut the wall from the outside inward, ensuring containment of radioactive materials within the building.

Implementation Method 1

a wire saw in which a plurality of diamond beads having greater hardness than that of a material constituting the structure is fitted

Methodology Applied

Scientific EffectAbrasion: Abrasion

Data Source

PatentUS20250114974A1Apparatus For Reverse Cutting Process For Nuclear Power Plant Structure

Publication Date: 2025.04.10 EGUN CO LTD

AI summary

The apparatus for reverse cutting of a structure, according to the present invention, comprises a pair of reverse pulley devices, the pair of pulley devices comprising: main tubes inserted and mounted so as to penetrate two holes; a pair of first support pulleys mounted on the inner sides of the front ends of the main tubes to rotatably support a wire; a pair of second support pulleys mounted on the inner sides of the rear ends of the main tubes to rotatably support the wire; openings which are cut in portions where the two main tubes face one another and allow the wire to move; and cap covers which are coupled to the front ends of the main tubes to seal same.