Ventilation unit for a freezer cabinet and method for operating a ventilation unit of this type

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Solution Overview

Problem

Existing ventilation systems in freezers, particularly ultra-low temperature freezers, suffer from wear and tear due to moving parts, leading to reduced service life and increased maintenance costs, and are complex to manufacture.

Innovation Solution

A ventilation unit for freezers featuring a pipe with an air-permeable filling material and a heating element, designed to equalize pressure differences by allowing air flow and defrosting through controlled heating, minimizing wear and simplifying manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional ventilation systems with valves and moving parts are used, then pressure equalization can be achieved, but wear and tear occurs leading to reduced service life and increased maintenance costs

Engineering Contradiction:
Improveservice lifeVSAvoidmoving parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes all moving parts (valves, actuators, mechanical components) from the ventilation system, extracting the problematic element that causes wear and tear. The system uses only static components: a pipe with air-permeable filling material and a heating element, eliminating the source of maintenance issues while maintaining pressure equalization functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical valve-based pressure equalization system with a thermal field-based system. Instead of using mechanical components to control air flow, the system uses a heating element to control the phase state of moisture in the filling material, thereby controlling air permeability through thermal fields rather than mechanical actuation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If conventional ventilation systems with valves are used, then pressure equalization can be achieved, but the systems are complex to manufacture

Engineering Contradiction:
Improvemanufacturing complexityVSAvoidvalve assemblies
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent extracts and removes complex valve assemblies from the manufacturing process, replacing them with simple static components that can be easily manufactured and assembled. The pipe with filling material and heating element requires no precision machining or assembly of moving parts, significantly simplifying manufacturing.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If the pipe is allowed to ice over to prevent undesired air flows, then air flow can be controlled, but the cross-section of the piping may be completely closed

Engineering Contradiction:
Improveair flow controlVSAvoidair flow
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent applies local quality by using air-permeable filling material distributed throughout the pipe, creating localized ice barriers at multiple points along the pipe rather than a single complete blockage. This allows controlled restriction of air flow while maintaining the ability to equalize pressure when needed, providing nuanced control over the ventilation function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses parameter changes by controlling the temperature state of the filling material through the heating element. By adjusting the thermal parameter (temperature), the system can transition the filling material between frozen and thawed states, thereby dynamically controlling air flow characteristics and ice formation without mechanical intervention.

Inventive Principle:
Principle #35Parameter changes

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 solution provides a ventilation system with a long service life, low maintenance requirements, and easy manufacturing, effectively managing pressure equalization by preventing icing and ensuring air flow through controlled heating.

Implementation Method 1

Activating the heating element, the ventilation unit can be defrosted, i.e. opened, or kept free of ice, i.e. kept open

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

The pipe can be made of a material with high thermal conductivity, in particular a metallic material. The high thermal conductivity enables rapid defrosting of the ventilation unit

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

an air-permeable filling material is arranged in the pipe at least in sections

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 4

This icing occurs in particular when condensate from the air settles and freezes

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 5

condensate from the air settles and freezes

Methodology Applied
Scientific EffectFreezing: Freezing

Implementation Method 6

This results in a pressure difference between the interior of the refrigerator and the environment

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3974749B1Ventilation unit for a freezer cabinet and method for operating a ventilation unit of this type
Publication Date: 2025.06.25 BINDER GMBH
  • EP3974749B1 patent drawingFigure 1
  • EP3974749B1 patent drawingFigure 2
  • EP3974749B1 patent drawingFigure 3

AI summary

Ventilation unit (10) for a freezer with a pipeline (20) and at least one heating element (30), wherein at least in sections an air-permeable filling material is arranged in the pipeline (20), as well as a freezer with such a ventilation unit and a method for operating such a ventilation unit (10).