Cooker Hood Filter Load Classification for Accurate Change Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining filter change time in extractor systems are inaccurate due to variations in fluid flow velocity, making it difficult to precisely assess filter load and efficiency.
Innovation Solution
A method that involves detecting a value characterizing the filter's degree of loading, storing it at specified intervals, classifying these values into classes based on frequency, determining a weighted number of values, and outputting a signal when the current load level exceeds a limit, allowing for precise filter change timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If operating hour counters are used to determine filter change time, then the device complexity is reduced, but the measurement precision of filter load assessment deteriorates due to variations in fluid flow velocity
Solution Approach 1:
The patent changes the measurement parameter from simple time duration to a composite parameter that includes both time and flow velocity measurements. The load level is calculated by integrating flow velocity over time, and this load level is then classified into classes with different weighting factors, creating a more accurate representation of actual filter load that accounts for varying operating conditions
Solution Approach 2:
The patent introduces an intermediary evaluation system that processes raw flow velocity measurements through classification and weighting. Instead of directly using operating hours, the system creates an intermediate load level parameter that mediates between simple time counting and complex direct filtration effect measurement, achieving better precision without proportionally increasing device complexity
2Ease of operation
If simple operating hour counting is implemented, then ease of operation is improved, but the reliability of filter change timing indication deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where flow velocity measurements continuously update the load level calculation. The system compares the calculated load level against threshold values and provides feedback signals when filter replacement is needed. This feedback loop ensures reliable timing indication while maintaining ease of operation through automatic monitoring and signaling
3Measurement precision
If flow velocity measurements are continuously monitored and processed with classification and weighting, then the measurement precision of filter load assessment is improved, but the device complexity increases
Solution Approach 1:
The patent segments the continuous range of load levels into discrete classes (first class, second class, third class, etc.) with specific weighting factors. This segmentation allows the system to process complex flow velocity data through manageable categories, improving measurement precision while controlling device complexity by using standardized classification thresholds and weighting multipliers
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention relates to a method for determining the filter change time of a filter substrate of a cooker hood system, wherein the filter substrate is subjected to a flow of a fluid to be filtered, comprising the steps of: acquiring a value characterizing the degree of contamination of the filter substrate and storing the characteristic value in a data memory if a threshold value is exceeded; performing a classification of the stored values and determining a number of stored values of each class, wherein either the classes are classified using a cumulative curve of the frequency of the stored measured values and the cumulative curve is created from the stored measured values, or the classes are classified by determining ranges corresponding to the classes, wherein the ranges are determined using a maximum and minimum value of the stored values;Determining a weighted number of values by weighting the number of stored values per class with class-specific weighting factors; determining a current load level using the weighted number of measured values and checking whether the current load level exceeds a limit value. The invention also describes a corresponding filter box and an arrangement of at least two fluidically connected filter boxes.