Fire Nozzle Helical Cam Flow Control for Velocity Consistency
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Solution Overview
Problem
Existing fire hose nozzles fail to produce a consistent fluid stream with variable flow rates, leading to inconsistent velocities and reduced effectiveness in firefighting due to irregularities in the nozzle design and the 'wall effect' that slows fluid near the nozzle interior.
Innovation Solution
A nozzle design featuring a rotatable end bell with cam followers and a spider structure that adjusts the flow rate by modifying the orifice restriction, ensuring a consistent fluid velocity throughout the stream, and an annulus ring for debris passage, maintaining a solid stream at any flow rate within the usable range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the inner diameter of the nozzle is deformed to adjust flow rate, then the flow rate is variable, but the velocity consistency deteriorates due to grooves and bumps
Solution Approach 1:
The nozzle employs a movable piston that can be positioned at different locations within the nozzle body to dynamically adjust the effective orifice area. This dynamic adjustment mechanism allows continuous variation of flow rate while maintaining a smooth, consistent velocity profile across the fluid stream, eliminating the velocity inconsistencies caused by deformed inner diameters in traditional nozzles.
2Productivity
If the flow rate is increased, then the reach and productivity improve, but the velocity consistency deteriorates due to the wall effect
Solution Approach 1:
The nozzle design incorporates specific geometric features including a rounded entrance and a precisely contoured piston surface that create localized flow conditions. These local quality modifications ensure that even at high flow rates, the velocity distribution remains uniform across the stream cross-section, counteracting the wall effect that typically causes velocity inconsistency at higher flows.
3Measurement precision
If a solid stream is maintained at variable flow rates, then the reach and accuracy improve, but the device complexity increases
Solution Approach 1:
The piston mechanism serves multiple functions: it adjusts the orifice area for flow rate control, maintains velocity consistency across the stream, and preserves stream coherence for accurate long-range projection. This multi-functional design achieves high measurement precision and stream accuracy without requiring multiple separate components, thereby limiting the increase in device complexity.
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 delivers a solid stream of fluid with consistent velocity across varying flow rates, enhancing reach and accuracy, and is capable of flushing debris, thus overcoming the limitations of prior art nozzles.
Implementation Method 1
one or more cam followers traverse along a helical shaped cam path, allowing an operatively associated slider to longitudinally move within a flow chamber of the nozzle to influence a flow rate through the nozzle
Implementation Method 2
The tapered entrance pin and the tapered exit pin accelerate and guide the flow of fluid prior to the fluid exiting the nozzle
Data Source
AI summary
A nozzle for use in dispensing a fluid, such as water or a foaming agent to extinguish a fire, comprises a longitudinal body that comprises a plurality of helical shaped cam paths. The cam paths allow the operator of the nozzle to adjust a flow setting for the nozzle by moving a flow adjustment mechanism that is operatively associated with the cam paths.