Refrigeration appliance and method for operating such appliance
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Solution Overview
Problem
Existing refrigeration appliances fail to effectively reduce pesticide residues and microorganisms on food surfaces while maintaining the natural quality, freshness, and nutritional aspects of stored fruits and vegetables during extended storage periods.
Innovation Solution
A refrigeration appliance with a dedicated compartment for fresh fruits and vegetables equipped with an ozone generating device, ozone sensor, and ethylene sensor, which maintains an optimal ozone concentration of 0.04-0.12ppm to reduce microbial growth and delay ripening, ensuring minimal impact on vitamin C content and overall food quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high ozone concentration is applied to reduce microbial growth and pesticide residues, then food safety and hygiene are improved, but food quality (color, ripening, freshness, nutritional aspects) deteriorates due to excessive oxidative processes
Solution Approach 1:
The ozone generator operates in periodic cycles with specific duty ratios (e.g., 30-70% duty cycle) rather than continuously, allowing ozone concentration to fluctuate between effective levels for microbial reduction and safe levels for food quality preservation. This periodic operation enables the system to achieve both food safety and quality maintenance.
Solution Approach 2:
The system dynamically adjusts ozone generation parameters including concentration levels (maintaining 0.03-0.15 ppm range), duty cycle ratios, and treatment durations based on detected ethylene concentrations and storage conditions. This parameter optimization allows effective microbial reduction while minimizing oxidative damage to food quality.
2Object-affected harmful factors
If ozone generation is increased to improve air quality and remove odors, then hygiene conditions are improved, but vitamin C content and nutritional quality deteriorate due to accelerated oxidation
Solution Approach 1:
The system uses ethylene sensors to detect ripening levels and adjusts ozone generation accordingly, maintaining ozone concentrations that improve air quality and remove odors while staying below thresholds that cause excessive vitamin C degradation. The feedback loop ensures ozone levels remain in the optimal 0.03-0.15 ppm range.
Solution Approach 2:
The ozone generation system dynamically adapts its operation based on real-time ethylene detection and storage duration, adjusting duty cycles and intensity to maintain beneficial air quality improvements while preventing excessive oxidation of nutritional components like vitamin C.
3Reliability
If continuous ozone treatment is applied to maintain food freshness, then microbial reduction is improved, but natural quality and sensory aspects deteriorate due to prolonged exposure
Solution Approach 1:
Instead of continuous treatment, the system applies periodic ozone pulses with controlled duty ratios, allowing food to experience intervals of normal atmosphere between ozone exposures. This maintains effective microbial reduction while preserving natural quality and sensory characteristics through reduced cumulative oxidative stress.
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 optimal ozone concentration effectively reduces microbial growth and slows down vitamin C decay, maintaining nutritional quality and prolonging the shelf life of fruits and vegetables without adverse effects on sensory or nutritional aspects.
Implementation Method 1
an ozone generating device (10) placed in a specific sealed housing (12) and fixed on a rear wall (14) of an inner liner of a fresh food compartment (A) of a refrigerator
Implementation Method 2
The effectiveness of ozone against microorganisms present in food systems depends on several factors including the amount of ozone applied... delay the ripening process by ethylene oxidation
Implementation Method 3
an ozone sensor configured to sense an ozone level inside the compartment
Implementation Method 4
an ethylene sensor configured to sense an ethylene level inside the compartment
Implementation Method 5
Excess ozone auto decomposes rapidly to produce oxygen and thus leaves no residues in foods from its decomposition
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A refrigeration appliance comprises a cavity in which an ozone generating device is placed. Said ozone generating device is configured to maintain in said cavity a concentration of ozone comprised between 0,04 and 0,12 ppm, more preferably between 0,06 and 0,1 ppm.