Spray Head Cover Retention via Thermal Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing spray heads often over-dispense fire extinguishing materials, causing damage and depleting supplies, and can be affected by temperature changes that cause covers to fall out, exposing nozzles to debris and leading to improper operation.
Innovation Solution
A spray head design featuring a facetted front face with angled nozzles and a sealing mechanism, including an energizing ring and gasket to maintain a seal despite thermal expansion, and a PTFE cover with a metallic filler to prevent blockages and ensure proper operation across temperature ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a press-fit cover is used to protect the spray head, then dust and debris protection is improved, but the cover falls out when exposed to temperature changes causing expansion and contraction
Solution Approach 1:
The patent applies thermal expansion by designing the cover and housing from materials with different coefficients of thermal expansion. The cover is made of PTFE with a metallic filler, while the housing is made of a different material that expands at a different rate during temperature changes. This differential expansion creates a self-retaining mechanism where the cover remains securely fitted despite thermal cycling, preventing the cover from falling out while maintaining protection against dust and debris.
Solution Approach 2:
The patent uses composite materials by incorporating a metallic filler within the PTFE cover material. This composite structure combines the low friction and chemical resistance of PTFE with the thermal stability and structural strength of metal. The composite material allows the cover to maintain its dimensional stability and retention properties across a wide temperature range while still providing effective protection against environmental contaminants.
2Productivity
If conventional nozzles are used, then fire extinguishing material is dispensed, but too much material is dispensed causing damage and depleting supplies
Solution Approach 1:
The patent applies parameter changes by modifying the nozzle geometry and flow characteristics to produce a fog-like mist pattern. The angled nozzles are designed with specific orifice sizes and orientations that atomize the fire extinguishing material into fine droplets. This parameter change in spray pattern and droplet size distribution improves fire suppression effectiveness while reducing the total quantity of material consumed, preventing both damage from over-application and depletion of supplies.
Solution Approach 2:
The patent utilizes phase transitions by creating a fog-like mist that transitions from liquid fire extinguishing material in the supply line to fine aerosol droplets at the nozzle exit. This phase transition from bulk liquid to dispersed droplets increases the surface area and evaporation rate of the extinguishing material, improving fire suppression efficiency while using less material overall, thereby reducing both damage and supply depletion.
3Productivity
If inert gas such as nitrogen is dispensed, then fire suppression is achieved, but health risks such as suffocation are created
Solution Approach 1:
The patent applies parameter changes by switching from inert gas (zero liquid content) to liquid fire extinguishing material with controlled composition. The liquid material parameters are optimized to provide effective fire suppression through fog formation and evaporation, while the material composition is selected to be non-toxic and safe for occupied spaces, eliminating the suffocation risk associated with inert gas displacement of oxygen.
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 design conserves fire extinguishing materials by generating a fog-like mist, reduces damage, and maintains nozzle functionality by preventing debris and thermal-induced cover displacement, ensuring effective fire suppression and easy cleaning.
Implementation Method 1
The press-fit cover, however, can easily fall out when the cover is exposed to a range of temperatures that causes the cover to expand and contract
Implementation Method 2
The design conserves fire extinguishing materials by generating a fog-like mist
Data Source
Figure 1~2
Figure 3
Figure 4~6
AI summary
Embodiments of the invention provide a spray head including a housing having a facetted front face with a plurality of intersecting surfaces. The spray head can include a nozzle in each one of the plurality of intersecting surfaces. The nozzle can be positioned within a first recess of the housing so that an outer end of the nozzle does not extend past an outer surface of the housing. The nozzle can generate and dispense a fog-like mist. The spray head can include a cover that substantially prevents an orifice of the nozzle from becoming blocked with debris. The cover can be installed within a second recess of the nozzle so that the cover is substantially flush with the outer surface of the housing.