Flow Rectifier Geometry for Short Inlet Accurate Flow Measurement
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Solution Overview
Problem
Existing flow conditioners for fluid measurement in pipelines face challenges in maintaining measurement accuracy at high Reynolds numbers, often requiring extended inlet paths and increased pressure loss, especially when turbulence intensity is high, which affects the precision of flowmeters like ultrasonic, vortex, and thermal flowmeters.
Innovation Solution
A flow conditioner design featuring a diffusor, flow rectifier, and confusor connected in series, with a guide system to prevent boundary layer separation and swirl, utilizing a sleeve-shaped deflection means and connecting elements to ensure a uniform turbulence profile, reducing the installed length and pressure loss while maintaining measurement precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional flow conditioner is used to reduce turbulence intensity, then measurement precision is improved, but the inlet path length must be increased to greater than 10 times the nominal diameter and pressure loss increases
Solution Approach 1:
The flow conditioner is divided into three distinct functional segments: a diffusor for flow expansion and swirl reduction, a flow rectifier with multiple obstructions for turbulence control, and a confusor for flow convergence. Each segment performs a specific function to progressively condition the flow, eliminating the need for excessively long inlet paths while achieving the required flow uniformity for accurate measurement.
Solution Approach 2:
The invention optimizes geometric parameters including the diffusor angle (5-15 degrees), confusor angle (10-20 degrees), and the spacing and configuration of flow obstructions in the rectifier. These parameter optimizations enable effective turbulence reduction and flow profile conditioning within a compact length of less than 10 times the nominal diameter, resolving the contradiction between measurement precision and inlet path length.
2Measurement precision
If a conventional flow conditioner is used to reduce turbulence intensity, then measurement precision is improved, but pressure loss increases to more than three times that of a smooth tube
Solution Approach 1:
The diffusor and confusor angles are optimized to be relatively shallow (5-15 degrees and 10-20 degrees respectively) to minimize flow separation and reduce pressure losses. The flow obstructions in the rectifier are carefully designed with specific spacing and geometry to control turbulence while maintaining pressure efficiency, achieving the required flow conditioning with pressure loss of less than three times that of a smooth tube.
Solution Approach 2:
The flow obstructions in the rectifier, which inherently create turbulence and pressure loss, are strategically designed and positioned to convert this harmful effect into beneficial flow conditioning. The obstructions generate controlled turbulence that enhances mixing and eliminates swirl, while the subsequent confusor smoothly converges the flow, transforming the energy dissipation into improved flow uniformity for accurate measurement.
3Reliability
If the inlet path is extended to greater than 10 times the nominal diameter to achieve stable measurement at high Reynolds numbers, then measurement stability is improved, but device complexity and installed space increase
Solution Approach 1:
Instead of using a simple extended straight inlet path, the invention segments the flow conditioning function into three compact components: diffusor, flow rectifier, and confusor. This segmentation achieves superior measurement stability at high Reynolds numbers (greater than 5000) within a shorter, more manageable length of less than 10 times the nominal diameter, reducing installed space and simplifying system integration.
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 solution achieves stable and precise fluid flow measurement with reduced pressure loss and turbulence, even at high Reynolds numbers, by minimizing the inlet path length to less than five times the nominal diameter and pressure loss to less than three times that of a smooth tube, ensuring accurate volume and mass flow measurements.
Implementation Method 1
a guide system arranged within the lumen, especially a guide system serving for preventing boundary layer separation and for removing swirl from the flowing fluid
Implementation Method 2
a guide system serving for preventing boundary layer separation and for removing swirl from the flowing fluid
Implementation Method 3
a flow conditioner... especially one serving for a reducing a degree of turbulence, or an intensity of turbulence (turbulence intensity), of the (measured substance-)flow
Data Source
AI summary
The flow conditioner comprises a diffusor with a guide system arranged within its lumen, a flow rectifier with a disc shaped flow obstruction arranged within its lumen, wherein the flow obstruction has a plurality of flow openings, as well as a confusor, wherein diffusor, flow rectifier and confusor are connected fluidically in series to form a flow path extending from a flow opening of the diffusor to a flow opening of the confusor and involving the lumina of diffusor, flow rectifier and confusor. The guide system of the diffusor includes a sleeve shaped deflection means as well as a plurality of mutually separated connecting elements connected both with the deflection means as well as with the wall of the diffusor. The guide system is so formed and so positioned that the deflection means is spaced from the wall of the diffusor and arranged coaxially with the lumen of the diffusor.