Two-Phase Flow Liquid Atomiser for Fire Mist Dispersion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing portable water fire extinguishers face limitations in dispersing water to achieve a fire mist due to limited motive gas availability, leading to inefficient dispersion and potential post-fire damage, as they often rely on high pressure for single-phase liquid stream breakup, which is not sustainable throughout the discharge process.
Innovation Solution
The device incorporates a plunger tube with a liquid flow restrictor and strategically positioned side openings that increase in perpendicular distance from the restrictor towards the top, allowing for a controlled two-phase flow with enhanced gas and liquid proportioning, coupled with a composite exit nozzle for efficient mist generation and dispersion throughout the discharge cycle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high pressure is used to breakup the liquid stream for mist generation, then the dispersion level is improved, but the device complexity and energy consumption increase
Solution Approach 1:
The patent introduces a gas phase into the liquid stream through a plunger tube with side openings, creating a two-phase flow system. Gas bubbles rise through the liquid in the plunger tube, causing mechanical disruption and dispersion of the liquid stream without requiring high pressure. This pneumatic-hydraulic approach achieves fine mist dispersion while avoiding complex high-pressure mechanisms.
Solution Approach 2:
The patent changes the flow parameters by introducing a gas phase into the liquid stream. The gas flow rate and liquid flow rate are controlled to create optimal two-phase flow conditions. By adjusting these parameters, the system achieves effective mist generation at lower pressures compared to single-phase high-pressure systems.
2Device complexity
If a single-phase liquid stream is used for fire suppression, then the device structure is simpler, but the mist dispersion effectiveness is reduced
Solution Approach 1:
The patent combines gas and liquid phases in the plunger tube to create a two-phase flow system. The gas bubbles rising through the liquid create mechanical disruption and enhance dispersion. This approach maintains relatively simple device structure while significantly improving mist dispersion effectiveness compared to single-phase systems.
Solution Approach 2:
The patent utilizes the phase transition from separate gas and liquid phases to a dispersed two-phase mixture. Gas bubbles are introduced into the liquid stream, and through phase interaction and mixing, a fine mist plume is generated. This phase transition mechanism enhances dispersion effectiveness without requiring complex high-pressure equipment.
3Reliability
If the water fill rate is increased to improve fire suppression effectiveness, then the fire suppression effectiveness is improved, but the motive gas availability is depleted faster
Solution Approach 1:
The patent optimizes the ratio of gas flow rate to liquid flow rate to achieve effective mist generation with reduced water consumption. By controlling these flow parameters, the system maintains fire suppression effectiveness while extending the duration of operation and preserving motive gas availability throughout the discharge process.
Solution Approach 2:
The two-phase flow mechanism allows for more efficient utilization of motive gas. The gas bubbles provide continuous mechanical disruption and dispersion throughout the liquid stream, enabling effective mist generation with lower liquid flow rates compared to single-phase systems, thereby extending gas availability.
4Object-affected harmful factors
If pure water is used as the extinguishing agent, then the environmental friendliness is improved, but the electrical conductivity causes post-fire damage
Solution Approach 1:
The patent uses phase transition and mechanical disruption to create a fine mist plume from pure water. The two-phase flow mechanism breaks the liquid into extremely fine droplets, which evaporate quickly and leave minimal residue. This reduces the harmful electrical conductivity effect while maintaining the environmental benefits of using pure water as the extinguishing agent.
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 configuration ensures a stable and effective mist plume with droplet sizes below 120 micrometers, achieving a throw distance of up to 11 meters and maintaining high fire suppression effectiveness throughout the discharge process, even with reduced water fill rates, while avoiding corrosion and thermal shock.
Implementation Method 1
The plunger tube, in its lowermost part, where it almost touches bottom of the reservoir, has an ingress channel, often fitted with a filter... the head assembly has various kinds of body fittings... a dispersion chamber... This configuration ensures a stable and effective mist plume with droplet sizes below 120 micrometers
Implementation Method 2
an influx of gas into a stream of liquid agent inside the tube generates a two-phase flow in a form of bubbles of gas carried by a torrent of the liquid
Implementation Method 3
required pressures values at the supply side are lower... achieving a throw distance of up to 11 meters and maintaining high fire suppression effectiveness
Implementation Method 4
a highly dispersed plume of mist, adequate for fire suppression applications... droplet sizes below 120 micrometers
Data Source
Figure 1
Figure 2A
Figure 2B~3D
AI summary
The subject of the invention is a device ensuring a two-phase flow in a liquid atomiser, equipped in its upper part with a discharge control assembly, the device contains at least one egress channel, as well as a plunger tube, placed below this assembly and interconnected with this assembly, the plunger tube having in its lowermost section an ingress channel, optionally outfitted with a filter to keep away impurities, and interconnected with a discharge control assembly, and further downstream with an egress channel, wherein the plunger tube (5) is outfitted with a liquid flow restrictor (6) and, above the latter, a row of side openings (9) connecting external space of the tube (5) with its inner channel, where the successive side openings (9) are positioned longitudinally along the tube (5) at different distances from the restrictor (6). Same invention covers liquid atomiser comprising said device and method of altering atomiser.