Fluid Control Valve Cutout Rim Design for Zero Flow Decay
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Solution Overview
Problem
The existing pressure type mass flow controllers face challenges in achieving zero flow rate measurement quickly after the fluid control valve is fully closed, due to residual fluid volume, which complicates semiconductor manufacturing processes and makes replacement difficult.
Innovation Solution
A fluid control valve design with a single in-valve flow path and a protruded rim with cutouts, allowing fluid to flow directly from the upstream to the downstream path, reducing the internal volume and enabling faster decay to zero flow rate measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the fluid control valve is provided with multiple in-valve flow paths to ensure sufficient fluid flow, then the fluid flow capability is improved, but the inside volume of the valve increases and the time to reach zero flow rate measurement after closing is extended
Solution Approach 1:
The protruded rim is divided into multiple segments by forming cutouts, creating multiple fluid passage channels. This segmentation allows fluid to flow through multiple paths around the valve element member, ensuring sufficient fluid flow capability while keeping the overall valve structure compact and minimizing inside volume.
Solution Approach 2:
The fluid passage is extended in the radial direction by forming cutouts in the protruded rim, rather than only in the axial direction. This dimensional change creates additional flow paths that increase fluid flow capability without significantly increasing the axial length or overall volume of the valve.
2Reliability
If the fluid control valve is fully closed to stop fluid flow, then the flow control function is improved, but residual fluid in the internal volume causes the flow rate measurement to decay slowly to zero
Solution Approach 1:
Cutouts are formed in the protruded rim to create direct communication paths between the upstream and downstream flow paths that bypass the valve element member. When the valve is closed, residual fluid can be quickly extracted and discharged through these cutout passages, allowing the flow rate measurement to reach zero quickly without being trapped in large internal volumes.
3Volume of stationary object
If the valve seat block is miniaturized to reduce inside volume, then the volume from valve to sensor is reduced and zero flow rate is reached faster, but the fluid flow capability may be compromised
Solution Approach 1:
The cutout passages are nested within the protruded rim structure of the valve seat block, utilizing the existing radial space efficiently. This nesting approach creates additional fluid passage capacity without increasing the overall valve dimensions, allowing miniaturization while maintaining fluid flow capability.
Data Source
AI summary
In order to, in a short period of time, reduce to zero a measured flow rate value measured after fully closing a fluid control valve, the fluid control valve having a configuration suitable to decrease the inside volume of the fluid control valve is configured together with a valve element member, and a valve seat block provided with: an in-valve flow path that is formed inside of the valve seat block; and a valve seat surface that is brought into contact with or separated from a seating surface of the valve element member is provided with a cutout that is formed in a part of a protruded rim so as to be communicatively connected to a downstream side flow path.