Fan Heater Nozzle Design for Split Air Flow and Surface Cooling
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Solution Overview
Problem
Conventional fan heaters produce non-uniform and turbulent air flows due to variations in blade surface and heating element distribution, leading to discomfort and reduced heating effectiveness with distance, while also posing safety concerns and maintenance issues with dust accumulation and hot surface temperatures.
Innovation Solution
A nozzle design for fan assemblies that divides the air flow into heated and unheated streams, allowing for adjustable temperature control and emission through multiple outlets, with heating elements located within the nozzle to prevent external surface overheating and dust burning, and a Coanda surface to enhance air entrainment and flow uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heating elements are located externally in conventional fan heaters, then heating capability is achieved, but external surfaces overheat and dust accumulates leading to burning and unpleasant smells
Solution Approach 1:
The heating element is nested within the nozzle interior passage, with the heating coil positioned inside the air flow path. This nesting arrangement allows the heating element to be enclosed by the nozzle structure, preventing external surface overheating and dust accumulation on the heating elements themselves, thereby eliminating the burning smell problem while maintaining heating capability.
Solution Approach 2:
The air flow acts as an intermediary between the heating element and the external environment. The heated air stream carries the thermal energy from the internally positioned heating element to the user, while the nozzle structure serves as a mediator that isolates the heating element from external dust and prevents external surface overheating.
2Productivity
If blades are used to generate air flow, then air circulation is achieved, but non-uniform and turbulent air flow is produced reducing heating effectiveness
Solution Approach 1:
The air flow is segmented into multiple discrete streams by the nozzle interior passage, which divides the air flow into several parallel streams. These segmented streams are then recombined at the outlet to form a unified, more uniform air current. This segmentation approach eliminates the turbulent mixing caused by traditional blades while maintaining effective air circulation.
Solution Approach 2:
The mechanical blade system is replaced with a nozzle-based air flow division and recombination system. Instead of using rotating blades to generate air flow, the invention uses a stationary nozzle with internal passages to divide and direct air streams, eliminating the mechanical complexity and turbulence associated with blade rotation while achieving uniform air flow.
3Object-affected harmful factors
If caged or apertured casing is used to protect blades and heating elements, then user safety is improved, but cleaning becomes difficult and dust accumulates
Solution Approach 1:
The heating element is extracted from the traditional enclosed casing position and relocated to the nozzle interior passage. This extraction allows the heating element to be positioned where it is naturally protected by the nozzle structure during operation, while the open nozzle design maintains ease of access for cleaning. The blade protection function is achieved through the nozzle geometry itself rather than an additional cage structure.
Solution Approach 2:
The nozzle structure serves multiple functions: it directs the air flow, houses the heating element, protects the heating element from external contamination, and maintains user safety by shielding hot surfaces. This multi-functionality eliminates the need for separate protective cages while preserving safety and improving cleanability.
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 nozzle design provides a uniform and adjustable air current with improved heating efficiency, reduces external surface temperatures, and enhances user safety by preventing dust burning and maintaining a clean exterior, while ensuring effective air circulation and comfort.
Implementation Method 1
The nozzle defines a central opening through which air in the local environment of the fan assembly is drawn by the primary air flow emitted from the mouth, amplifying the primary air flow to generate an air current
Implementation Method 2
a Coanda surface to enhance air entrainment and flow uniformity
Data Source
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AI summary
A fan assembly includes a motor-driven impeller for creating an air flow, and a casing including an interior passage for receiving the air flow, and a plurality of air outlets for emitting the air flow from the casing. The casing defines and extends about an opening through which air from outside the casing is drawn by the air flow emitted from the air outlets. The fan assembly also includes at least one heater for heating at least a first portion of the air flow, and means for diverting at least a second portion of the air flow away from said at least one heater. The plurality of outlets includes at least one first air outlet for emitting the relatively hot first portion of the air flow and at least one second air outlet for emitting the relatively cold second portion of the air flow. This second portion of the air flow may be directed over an external surface of the casing to keep that surface cool during use of the fan heater.