Vapour Extraction Fan Control Using Fan-Box Odor Sensing
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Solution Overview
Problem
Existing fume extraction devices experience erratic fan stage switching and turbulent flows, making it difficult to accurately detect odors and vapors, especially at higher air delivery rates, which affects the air cleaning effect and reliability of sensors like ultrasonic sensors.
Innovation Solution
A fume extraction device with a sensor arranged inside the fan box to detect odors and vapors, using a microcontroller to process sensor information and adjust fan levels based on flexible reference values that account for changing odor conditions, allowing for precise control of fan speed and improved air cleaning efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the sensor is arranged outside the extractor device in the visible area, then the device structure is simple and easy to manufacture, but the sensor detection reliability deteriorates due to turbulent flows at higher air delivery rates
Solution Approach 1:
The sensor is nested inside the fan box housing, which contains the fan assembly. This internal arrangement protects the sensor from external turbulent flows while maintaining detection capability through the housing structure, resolving the contradiction between manufacturing simplicity and detection reliability.
Solution Approach 2:
The fan box housing acts as an intermediary structure that allows the sensor to be positioned internally while still detecting odors and vapors from the cooking environment. The housing mediates between the need for sensor protection and the requirement for odor detection functionality.
2Device complexity
If predetermined fixed threshold values are used for each fan level, then the control system is simple, but erratic switching of fan stages occurs
Solution Approach 1:
The threshold values are changed from fixed predetermined values to dynamically adjustable values that adapt based on detected odor levels and cooking processes. This dynamic adjustment prevents erratic switching by allowing the system to respond smoothly to changing environmental conditions while maintaining simple control logic.
Solution Approach 2:
The control system uses feedback from the sensor to continuously adjust threshold values and fan stage switching decisions. This feedback mechanism stabilizes the control by preventing erratic transitions and ensuring that fan stage changes occur only when appropriate odor level changes are detected.
3Productivity
If the fan speed is increased to improve vapor extraction, then the air delivery rate increases, but turbulent flows are generated that interfere with sensor detection
Solution Approach 1:
The sensor is nested within the fan box housing, positioned to detect odors and vapors from the cooking environment while being shielded from the direct path of high-speed turbulent flows generated by the fan. This spatial arrangement allows high fan speeds for effective vapor extraction without compromising sensor detection accuracy.
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 reliable detection and extraction of odors and vapors, reduces erratic fan switching, and enhances air cleaning effectiveness by adjusting fan speed according to real-time odor levels, improving both power consumption and noise management.
Implementation Method 1
The sensor can provide the determined information, which is also referred to below as sensor information, for example in the form of an electrical signal, a pressure, an electrical resistance value and the like. Preferably, according to the invention, a gas sensor is used and its resistance is used to determine the odor level.
Data Source
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AI summary
The invention relates to a vapour extraction device (1) with a fan (2) having a fan motor, with a fan box and with a first sensor (31), wherein the vapour extraction device (1) is characterized in that the first sensor (31) is arranged in or on the fan box and that a first odour level (L) of a cooking environment of the vapour extraction device (1) is determined by means of the first sensor (31). The invention also relates to a method for controlling a fan motor (2) of a fan in a vapour extraction device (1) according to the invention, wherein the method comprises at least the following steps: performing a cooking process detection (400); performing an odour pollution determination with the aid of the result of the cooking process detection (400); and controlling the fan motor (2) of the vapour extraction device (1) to a fan level with the aid of the result of the odour pollution determination.