Flow Meter Impeller with Flat Vanes and Grooved Diffuser
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Solution Overview
Problem
Existing flow measuring devices for fluids, particularly in household washing appliances and food production equipment, have complex and expensive constructions due to the use of helical vanes in impellers and diffusers, which complicates their manufacturing and operation.
Innovation Solution
A flow measuring device with a simple and economical design featuring a flat vane impeller made of molded plastic and a diffuser with longitudinal grooves and transverse passages that direct fluid flows tangentially to the impeller, reducing complexity and cost while ensuring precise and reliable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If helical vanes are used in impeller and diffuser, then flow measurement function is achieved, but device complexity and manufacturing cost increase
Solution Approach 1:
Instead of using complex helical vanes to achieve the flow measurement function, the patent inverts the approach by using simple flat vanes in combination with a diffuser that has longitudinal grooves and transverse passages. The diffuser structure, rather than the impeller vanes, performs the primary function of directing fluid flow tangentially to the impeller, thereby achieving the measurement function with simpler components.
Solution Approach 2:
The diffuser is segmented into multiple longitudinal grooves that create separate flow passages. Each groove directs a portion of the fluid flow tangentially to the impeller vanes. This segmentation allows the complex flow direction function to be achieved through multiple simple grooves rather than a single complex helical structure.
2Reliability
If helical vanes are used in impeller and diffuser, then flow measurement function is achieved, but manufacturing cost increases
Solution Approach 1:
The patent shifts the functional burden from the expensive helical vanes to the diffuser structure with longitudinal grooves. The impeller can be manufactured as a simple structure with flat vanes, reducing impeller manufacturing cost. The diffuser, while containing grooves, can be manufactured as a single piece or with simpler processes than helical vanes.
Solution Approach 2:
The patent employs simpler materials and structures that can be manufactured more economically. The impeller with flat vanes and the diffuser with grooves can be made from molded plastic or other inexpensive materials, replacing the more expensive helical vane construction.
3Device complexity
If flat vane impeller with longitudinal groove diffuser is used, then device complexity and cost are reduced, but fluid flow control precision may be affected
Solution Approach 1:
The longitudinal grooves in the diffuser create multiple discrete flow passages that precisely control the direction and distribution of fluid flow to the impeller. Each groove acts as a separate flow channel, ensuring precise flow control while maintaining a simple overall structure.
Solution Approach 2:
The diffuser with longitudinal grooves acts as an intermediary element between the fluid source and the impeller. It mediates the fluid flow by directing it tangentially to the impeller vanes through the grooves, thereby achieving precise flow control without requiring complex impeller vanes.
4Reliability
If conventional impeller design is used, then flow measurement is achieved, but cavitation and turbulence increase
Solution Approach 1:
The diffuser with longitudinal grooves serves as a mediator that conditions the fluid flow before it reaches the impeller. By directing the flow tangentially through the grooves, it smooths the flow distribution and reduces turbulence and cavitation risks, protecting the impeller operation.
Solution Approach 2:
The diffuser performs preliminary flow conditioning and direction before the fluid reaches the impeller. The longitudinal grooves pre-direct the flow in a tangential direction, ensuring that the fluid enters the impeller in a controlled manner that minimizes cavitation and turbulence during the measurement process.
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 device provides a cost-effective and reliable method for measuring fluid flow rates with reduced risk of cavitation and turbulence, using a plastic impeller and diffuser configuration that linearizes fluid flow and minimizes friction and wear.
Implementation Method 1
having a plurality of vanes to be hit by a flow of said fluid to make the impeller rotate with an angular speed which is a function of the flow rate of said fluid
Implementation Method 2
a diffuser provided upstream of the impeller and defining a plurality of passages for dividing said flow into a plurality of reduced flows and directing the latter toward the vanes of the impeller
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The device (1) for measuring the flow rate comprises an impeller (10) to be rotatably mounted in said conduit (C), around an axis (X-X) and having a plurality of radial vanes (13) to be hit by a flow of said fluid for making the impeller (10) rotate with an angular speed which is a function of the flow rate of said fluid, and a detector (16, 17) associated with the impeller (10) to provide signals indicating the angular speed thereof. Upstream of the impeller (10) a diffuser (20) is provided defining a plurality of passages (21, 22) for dividing said flow into a plurality of reduced flows and directing said reduced flows toward the vanes (13) of the impeller (10), such as to make the latter rotate in a predetermined direction. The impeller (10) has a first axial portion (10a) close to the diffuser (20) and provided with blades (13), which are flat and lie in radial planes relative to the axis (X-X), and a second axial portion ( 10b) away from the diffuser (20) and provides a greater radial dimension than the first axial portion (10a), and to which the detector (16, 17) is associated. The diffuser (20) forms peripheral passages which extend in planes parallel to said axis (X-X) and inclined in a same direction about said axis (X-X); each passage (21, 22) having a longitudinal inlet portion (21), parallel to said axis (X-X) and a transverse outlet portion (22) laterally facing said first axial portion (10a) of the impeller (10) such that in operation, the outlet portions (22) of said passages (21, 22) direct towards the vanes (13) of the impeller (10) corresponding flows or jets of fluid in non-radial directions inclined in a same direction around said axis (X-X).