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Method for a linear nonintrusive flow restrictor

IP.com Disclosure Number: IPCOM000030174D
Publication Date: 2004-Jul-30
Document File: 2 page(s) / 47K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a linear nonintrusive flow restrictor. Benefits include a much finer flow adjustment and improved performance.

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Method for a linear nonintrusive flow restrictor

Disclosed is a method for a linear nonintrusive flow restrictor. Benefits include a much finer flow adjustment and improved performance.

Background

      The flow of a chemical must be controlled without introducing crystallization or microbubble formation. Conventionally, the flow is only controlled by regulating the dispense pressure on supply canisters. Controlling pressure precisely is very expensive and complex.

      In dispensing process chemicals, the conventional flow-control valves have many sharp surfaces and areas of sudden pressure drop. The interior of all flow control valves are in some way machined. The pressure drops and machined surfaces cause the chemicals to crystallize and cause defects. Additionally, they cause microbubbles that cause defects.

Description

              The disclosed method controls a chemical by setting the pressure at a value and adjusting the flow by adjusting the restriction. Tubing is routed around the inside of a cavity with two jaws that are wedged out against the tubing. The tubing compresses and reduces the volume, producing a reduction in flow rate (see Figure 1).

              The key elements of the disclosed method include:

•             A long length of tubing.

•             A cavity in which a long length of tubing can be constrained to allow for compression.

•             A device that forces the long length of tubing to collapse in a controlled manner

Advantages

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