Apparatus for controlling and metering fluid flow including a variable orifice

Abstract

A device for metering and controlling fluid flow includes a variable orifice and is configured to use a pressure sensor. The device includes a fluid flow conduit having at least one planar inner wall that extends along a portion of the fluid flow conduit length, and an element having a linear edge configured to mate with the at least one planar inner wall of the fluid flow conduit. The element is movable in a direction transverse to an axis of the conduit between an open position wherein fluid flows through the conduit and a closed position wherein the element substantially shuts off fluid flow in the conduit.

Description

[0001] This application is an International Patent Application filed in the name of Revatec, Inc., an American company, claiming U.S. Provisional Patent Application 60 / 500,774, filed September 4, 2003, and U.S. Patent Application 6, filed December 3, 2003 Priority of application 10 / 728,594. technical field [0002] The present invention relates generally to fluid flow and, more particularly, to a variable orifice for metering and controlling fluid flow. Background technique [0003] In the process control industry, small diameter tubing is often used to carry process fluids at low flow rates when small quantities of fluids are required in a manufacturing process. The duct is almost always of circular cross-section. Instruments used in pipelines to measure flow rates must be in contact with the fluid flowing in the pipeline while minimizing disturbance to the fluid flow. To minimize disturbance to fluid flow, the instruments are generally of circular cross-section to match ...

AI Technical Summary

Problems solved by technology

Due to the curved nature of these components, the shape of the orifice changes with the orifice size, which leads to significant errors when calculating fluid flow over a range of orifice sizes

Second, variations in the shape of the orifice result in a non-ideal shape of the orifice over at least a portion of the flow range

This leads to inconsistent flow characteristics for any given opening as the flow rate varies, again causing errors in the calculation of fluid flow

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