Flowmeter Rectifier Structure for Shorter Upstream Straight Pipe
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Solution Overview
Problem
Current ultrasonic gas flowmeters and other flowmeters require lengthy upstream straight tubes to achieve a symmetrical flow field, leading to increased installation space and maintenance challenges.
Innovation Solution
A rectifier with a cowl design featuring a first rectifying section upstream, a reduced diameter section midstream, and a second rectifying section downstream, which includes rectifying passages and side wall channels to improve fluid uniformity and reduce vortex, while maintaining low pressure loss and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a lengthy upstream straight tube is used to develop a symmetrical flow field, then measurement precision is improved, but installation space and device complexity increase
Solution Approach 1:
The rectifier is divided into multiple functional sections: a first rectifying section with rectifying passages, a reduced diameter section, and a second rectifying section. This segmentation allows each section to perform a specific flow conditioning function, achieving symmetrical flow field development in a compact structure rather than requiring a long straight tube.
Solution Approach 2:
Instead of extending the flow conditioning in the flow direction (one dimension), the invention uses rectifying passages arranged in parallel and a reduced diameter section to achieve flow straightening in a compact cross-sectional configuration. This dimensional transformation enables flow field symmetrization within a short axial length.
2Length of stationary object
If a rectifier with multiple sections is used to reduce upstream straight tube length, then installation space is reduced, but device complexity increases
Solution Approach 1:
Multiple flow conditioning functions (flow straightening, flow contraction, and flow symmetrization) are merged into a single integrated rectifier body with three sections. This consolidation achieves the flow field development that would otherwise require separate components and a long straight tube, reducing overall complexity despite the multi-section design.
Solution Approach 2:
The rectifier serves multiple functions simultaneously: the first rectifying section straightens flow, the reduced diameter section contracts and centers the flow, and the second rectifying section further symmetrizes the flow field. This multi-functionality in a single component reduces the need for multiple separate flow conditioning devices.
3Stability of the object's composition
If the reduced diameter section has a smaller diameter, then flow uniformity is improved, but pressure loss increases
Solution Approach 1:
The reduced diameter section is strategically positioned between two rectifying sections, creating a localized flow contraction zone. This local quality change concentrates the flow toward the center and improves uniformity, while the surrounding rectifying passages mitigate pressure loss by providing flow guidance and recovery paths.
Solution Approach 2:
The rectifying passages act as intermediary structures that connect the reduced diameter section to the upstream and downstream systems. These passages mediate the pressure transition by gradually adjusting the flow, reducing the abrupt pressure loss that would occur with a sudden diameter change while maintaining flow uniformity.
Data Source
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AI summary
A rectifier and a flowmeter, the rectifier including a fairing, wherein a first rectifying section (1) positioned at the upstream, a reducing section (2) positioned at the midstream and a second rectifying section (3) positioned at the downstream, can be arranged in the fairing. The first rectifying section and the second rectifying section are respectively provided with a group of rectifying channels parallel to the flow direction of fluid, and a through-hole (21) can be formed in the reducing section. The rectifier can provide improved rectification effects.