Adjustable Fuel-Air Mixing Device for Heating Appliances
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Solution Overview
Problem
Existing fuel-air mixing devices in heaters are limited in their ability to vary power output, as they struggle to maintain a consistent fuel-air mixture across a wide range of modulation, especially when the fan output is adjusted.
Innovation Solution
A fuel-air mixing device with an adjustable opening at the constriction, secured by a locking device, allows for precise adjustment and locking of the fuel-air mixture, ensuring a constant ratio over a wide power range by introducing fuel at high speed through an annular gap or adjustable orifice, primarily at the Venturi constriction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed opening is used in the fuel-air mixing device, then the device structure is simple, but the ability to vary power output is limited
Solution Approach 1:
The opening in the fuel-air mixing device is made adjustable rather than fixed, allowing the opening size to be dynamically changed to vary the fuel flow rate. This enables the heating appliance to operate at different power levels while maintaining proper fuel-air mixture ratios, directly resolving the contradiction between adaptability and structural simplicity.
2Adaptability or versatility
If the opening is made adjustable to vary fuel flow, then power modulation capability is improved, but the fuel-air mixture consistency deteriorates
Solution Approach 1:
The invention changes the opening size parameter to control fuel flow rate for different power levels. By providing multiple predetermined opening positions, the device maintains optimized fuel-air mixture ratios at each power level, ensuring mixture consistency across the full power range while enabling significant power modulation.
Solution Approach 2:
The opening is pre-adjusted to specific positions that correspond to optimal fuel-air mixture ratios for different operating conditions. This preliminary setup ensures that when the device operates at any power level, the fuel-air mixture maintains the correct composition, resolving the contradiction between power modulation and mixture consistency.
3Adaptability or versatility
If the opening is adjusted frequently to match power requirements, then power output adaptability is improved, but the reliability of the setting deteriorates
Solution Approach 1:
The continuous adjustment range of the opening is segmented into multiple discrete predetermined positions. Each position corresponds to a specific operating mode with an optimized fuel-air mixture ratio. The locking device secures the opening at these discrete positions, preventing accidental changes while maintaining the ability to switch between different power levels, thus resolving the contradiction between adaptability and setting reliability.
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
This solution enables precise control of the fuel-air mixture, stabilizing flow conditions and optimizing mixing ratios, allowing for significant power modulation and compensation for manufacturing tolerances and age-related changes, ensuring a consistent fuel-air ratio even with fan power variations.
Implementation Method 1
a fuel-air mixing device in the form of a Venturi feedthrough, in which air is forced into the Venturi inlet by a blower to be mixed with gas shortly after the Venturi constriction
Data Source
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AI summary
The invention relates to a heating appliance (10) and a fuel-air mixing device (16) for a heating appliance with a burner (14) assisted by a blower (12), a fuel-air mixing device (16) which supplies, via a line (30) of flowing air (20) in the region of a constriction (18), in particular gaseous fuel (22) through at least one opening (24). It is proposed that the opening (24) be adjustable.