Parallel Venturi Elements for Extinguishing Foam Generation
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Solution Overview
Problem
Conventional extinguishing foam generation systems require compressed air, which increases technical effort and costs, and do not allow for simple and inexpensive production of extinguishing foam close to the mixing point for efficient conveyance through hoses or pipes without compressed gases.
Innovation Solution
An arrangement with two Venturi elements connected in parallel, one for forming a foaming agent-water mixture and another for forming a gas-water mixture, where the outputs combine in a mixing chamber to produce extinguishing foam, reducing pressure loss and eliminating the need for compressed gases, allowing for cost-effective and easy handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional single Venturi element systems are used to generate extinguishing foam, then the system structure is simple, but the pressure loss is high (approx. 1/3 pressure loss) and the throwing range is limited
Solution Approach 1:
The single Venturi element is divided into two parallel Venturi elements (first and second Venturi elements), each handling a portion of the water flow. This segmentation reduces the pressure loss in each individual Venturi while maintaining the overall foam generation function, thereby improving the throwing range without significantly increasing system complexity.
Solution Approach 2:
The outputs of the two parallel Venturi elements are merged in a common outlet region where the foaming agent-water mixture from both Venturi elements combines. This merging allows the system to benefit from reduced pressure loss while maintaining the necessary foam concentrate mixing ratio, effectively resolving the contradiction between simplicity and energy efficiency.
2Productivity
If compressed air foam systems (CAFS) are used to increase throwing range and improve foam quality, then the foam performance is enhanced, but the technical effort and costs increase considerably
Solution Approach 1:
The complex compressed air supply system of CAFS is extracted and replaced with a simpler parallel Venturi system that uses only water pressure to generate the foam. This extraction eliminates the need for separate compressed air generators, storage tanks, and control systems, thereby reducing technical effort and costs while maintaining enhanced throwing range through the optimized parallel flow configuration.
Solution Approach 2:
Instead of using pneumatic compressed air systems, the invention employs purely hydraulic principles through the parallel Venturi elements to achieve the same performance enhancement. The water flow itself creates the suction effect and mixing action needed for effective foam generation, eliminating the need for complex pneumatic infrastructure.
3Ease of operation
If conventional foam delivery systems are used, then the system is simple to operate, but the hose filled with foam mixture is heavy and handling is difficult
Solution Approach 1:
The foam is generated and ready for delivery at the moment of need through the parallel Venturi system, eliminating the need to pre-fill hoses with heavy foam concentrate-water mixtures. The system generates foam on-demand at the delivery point, so hoses remain lightweight and easy to handle while still providing effective foam delivery when required.
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 solution enables the production of extinguishing foam with sufficient pressure for conveyance through hoses without compressed gases, offering cost-effective, easy-to-use, and maintainable systems that can be used in various firefighting operations without interrupting the firefighting process.
Implementation Method 1
the admixture takes place either according to the suction jet or jet pump principle as an injector ("water jet pumps") or as a tube with a narrowing of the cross section ("Venturi tubes") and suction tube in the area of the narrowing of the cross section. Both constructions use the effect that the increase in flow velocity in a narrowed tube (nozzle) creates a pressure drop, which in turn leads to a suction effect in this area (Venturi effect)
Implementation Method 2
the gas supply device has a second venturi element connected in parallel to the first venturi element to form a gas-water mixture, which has a water inlet through which a water stream can be fed under pressure, an optionally closable gas inlet through which the gas can be fed in, has a mixing area in which the gas can be admixed with the water flow according to the venturi principle
Implementation Method 3
a mixing chamber, which serves to form the extinguishing foam from the foaming agent-water mixture and the gas-water mixture
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
The invention relates to an assembly (10) for producing an extinguishing foam, comprising a first Venturi element (12) for forming a foaming agent/water mixture. The Venturi element has a water inlet (16), a selectively closable foaming agent inlet (18), a mixing region (20) in which the supplied foaming agent can be mixed with the supplied water flow according to the Venturi principle, and an outlet (22) for the foaming agent/water mixture. The assembly also comprises a gas supply device (15), via which a gas can be supplied to the foaming agent/water mixture in order to form the extinguishing foam, and an extinguishing foam outlet (34) for dispensing the extinguishing foam. The gas supply device has a second Venturi element (14) which is connected parallel to the first Venturi element in order to form a gas/water mixture. The second Venturi element has a water inlet (24), a selectively closable gas inlet (26), a mixing region (28) in which the supplied gas can be mixed with the supplied water flow according to the Venturi principle, and an outlet (30) for the gas/water mixture. The outlets of the Venturi elements open into a mixing chamber (32) which is used to form the extinguishing foam from the foaming agent/water mixture and the gas/water mixture and from which the extinguishing foam is discharged.