Granulated particles for cold storage material particles, granulated particle group for cold storage material particles, cold storage material particles, cold storage material particle group, cold storage device, refrigerator, cryopump, superconducting magnet, nuclear magnetic resonance imaging apparatus, nuclear magnetic resonance apparatus, magnetic field application-type single crystal pulling apparatus, helium recondensation apparatus, and dilution refrigerator

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Solution Overview

Problem

Conventional cold storage material particles struggle with low specific surface area, leading to reduced refrigeration performance and difficulty in achieving high-density filling without clogging or pulverization, which affects the efficiency and reliability of cryogenic refrigerators.

Innovation Solution

Granulated particles with recesses on their surface, made from rare earth oxysulfides or oxides, are designed to increase the specific surface area and improve mechanical strength, allowing for enhanced refrigeration performance and high-density filling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional cold storage material particles are used, then high-density filling can be achieved, but the specific surface area is low leading to reduced refrigeration performance

Engineering Contradiction:
Improvefilling densityVSAvoidspecific surface area
Core Design Contradiction:
Quantity of substanceVSArea of stationary object

Solution Approach 1:

The invention introduces particles with hollow internal structures (spheroidal, cylindrical, or irregular hollow shapes) to increase the specific surface area. These porous/hollow structures provide additional internal surfaces for heat exchange with helium gas while maintaining compact particle dimensions, thereby improving refrigeration performance without sacrificing filling density.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The hollow internal structure of the particles creates nested void spaces within the particle body. This nesting approach allows the particles to maintain high density while providing extensive internal surface areas for thermal exchange, effectively resolving the contradiction between compact filling and surface area availability.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Quantity of substance

If particles are made with higher surface area, then refrigeration performance improves, but mechanical strength decreases causing pulverization and clogging

Engineering Contradiction:
Improverefrigeration performanceVSAvoidmechanical strength
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The invention employs composite particle structures combining solid wall materials with hollow internal spaces. The solid portions maintain mechanical strength while the hollow structures provide increased surface area. This composite approach allows simultaneous achievement of high refrigeration performance and adequate mechanical strength to prevent pulverization and clogging.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The hollow structures are strategically designed with controlled wall thicknesses and internal geometries. The local quality of the particle structure is optimized such that walls maintain sufficient strength while internal cavities maximize surface area, resolving the contradiction between mechanical integrity and refrigeration efficiency.

Inventive Principle:
Principle #3Local quality

3Loss of energy

If particle surface area is increased to improve heat exchange, then thermal efficiency improves, but particle complexity increases making manufacturing difficult

Engineering Contradiction:
Improvethermal efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The invention predominantly uses spheroidal or near-spheroidal particle shapes with hollow interiors. This curved, rounded geometry simplifies manufacturing compared to complex angular or irregular shapes, while still providing large surface areas through the hollow structure. The spherical base form facilitates easy production via common ceramic or metalworking techniques.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The particles are designed as discrete, individual units with standardized hollow geometries. This segmentation into uniform, manufacturable units simplifies production processes and quality control, while the hollow design within each unit maintains high thermal efficiency. The modular nature of these particles makes them easier to manufacture at scale compared to monolithic complex structures.

Inventive Principle:
Principle #1Segmentation

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

The granulated particles with surface recesses enhance the refrigeration performance by increasing the contact area with helium gas, improving thermal efficiency and mechanical strength, while maintaining high-density filling in cryogenic refrigerators.

Implementation Method 1

cold is generated by heat exchange between the cold storage material and helium gas passing through the cold storage device

Methodology Applied
Scientific EffectHeat exchange: Conduction (thermal)

Data Source

PatentEP4682220A1Granulated particles for cold storage material particles, granulated particle group for cold storage material particles, cold storage material particles, cold storage material particle group, cold storage device, refrigerator, cryopump, superconducting magnet, nuclear magnetic resonance imaging apparatus, nuclear magnetic resonance apparatus, magnetic field application-type single crystal pulling apparatus, helium recondensation apparatus, and dilution refrigerator
Publication Date: 2026.01.21 NITERRA MATERIALS CO LTD
  • EP4682220A1 patent drawingFigure 1
  • EP4682220A1 patent drawingFigure 2
  • EP4682220A1 patent drawingFigure 3

AI summary

Granulated particles for cold storage material particles according to one embodiment contain a rare earth oxysulfide that contains at least one rare earth element selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, or a rare earth oxide that contains at least one rare earth element, and the granulated particles each have a plurality of recessed parts in the surface, the outer edge of each recessed part being a closed curve.