Fluidic Premixer With Movable Shutter for Wide Flow Rate Control

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Solution Overview

Problem

Existing foam concentrate injection and metering systems for firefighting are heavy, expensive, maintenance-intensive, and limited in their ability to operate over a wide range of flow rates, with Venturi-type systems being inflexible and only suitable for specific equipment.

Innovation Solution

A fluidic premixer that uses a conduit with a convergent and divergent section to create a Venturi effect, allowing for the injection of additives into a pressurized fluid stream, with a movable shutter to regulate flow rates and maintain suction independently of the main fluid flow, enabling precise metering and operation over a wide range of flow rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a Venturi-type system is used for additive injection, then the system is simpler and less expensive, but it requires a precise flow rate and cannot operate over a wide range of flow rates

Engineering Contradiction:
Improvesystem complexityVSAvoidflow rate range
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies the dynamics principle by making the neck section geometry variable through a movable shutter that can adjust the cross-sectional area of the neck. This dynamic adjustment allows the Venturi system to adapt to different flow rates while maintaining proper suction conditions, resolving the contradiction between system simplicity and flow rate versatility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the geometric parameter of the neck cross-sectional area using a movable shutter mechanism. By varying this parameter, the system can operate effectively across a wide range of flow rates while maintaining the simple Venturi-type structure, thus resolving the contradiction between simplicity and adaptability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If mechanical systems are used for foam concentrate injection, then they operate reliably over a wide flow rate range, but they are relatively heavy and expensive

Engineering Contradiction:
Improveoperational reliabilityVSAvoidsystem weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent replaces complex mechanical injection systems with a fluidic Venturi-based system that uses fluid dynamics principles. The movable shutter is actuated by fluid pressure differences rather than complex mechanical mechanisms, reducing system weight while maintaining reliability and wide flow rate operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses pneumatic and hydraulic principles by employing fluid pressure differences to actuate the movable shutter and control the neck geometry. This eliminates the need for heavy mechanical drive systems while maintaining reliable operation across wide flow rate ranges.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Productivity

If electronic systems are used for foam concentrate injection, then they operate over a wide range of throughput, but they are dependent on electrical power supply and require frequent maintenance

Engineering Contradiction:
Improvethroughput rangeVSAvoidmaintenance frequency
Core Design Contradiction:
ProductivityVSEase of repair

Solution Approach 1:

The patent replaces electronic control systems with a purely fluidic control mechanism using pressure-driven shutter actuation. This eliminates dependence on electrical power supplies and reduces maintenance requirements while maintaining wide throughput capability through geometric adjustment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The movable shutter is actuated automatically by fluid pressure differences within the system itself, without requiring external electronic control or power sources. The system self-regulates the neck geometry based on operating conditions, eliminating maintenance-intensive electronic components while maintaining productivity.

Inventive Principle:
Principle #25Self-service

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 premixer provides a lightweight, reliable, and cost-effective solution for injecting additives into fluids across various flow rates, ensuring precise metering and adaptability to different systems, reducing pressure drop, and simplifying maintenance, making it suitable for diverse applications including firefighting, agriculture, and industry.

Implementation Method 1

A Venturi-type system allows the injection of liquid into a network under pressure. This injection is obtained by suction of the liquid to be injected thanks to a reduction in the static pressure. It is an increase in the speed in the network that allows the static pressure to drop.

Methodology Applied
Scientific EffectVenturi effect: Venturi Effect

Data Source

PatentEP3092065B1Premixer and associated installation
Publication Date: 2019.07.10 LEADER
  • EP3092065B1 patent drawingFigure 1~2
  • EP3092065B1 patent drawingFigure 3~4

AI summary

The invention relates to a fluid premixer for mixing a first fluid and a second fluid by aspirating the second fluid into the first fluid using a Venturi effect, the premixer comprising a pipe (12) comprising: - a first inlet (16) for the first fluid at a first pressure, - a second inlet (18) for the second fluid that is to be mixed with the first fluid to form a mixture, - an outlet (22) for the mixture at a second pressure, and - a shutter (24) of the pipe (12) able to move between a number of positions each one defining a distinct degree of shutting of the pipe (12), the premixer further comprising a control element (34) able to control the position of the shutter (24) according to the difference between the first pressure and the second pressure.