Fluid-lock fixed-volume injector

US5487313A · kind A · utility

Assignee

• Microsensor Technology · US

Inventor

• Paul H. Johnson · Snohomish, US

Key dates

• Filing date: Nov 30, 1993
• Grant date: Jan 30, 1996
• Expiry date: Nov 30, 2013

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2035/00237
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An automated micro-valve assembly injects a fixed fluid volume fluid into a destination stream. The fluid to be injected (inject fluid) is conducted into a chamber. Flow of inject fluid out of the chamber is prevented by sealing the ends of the chamber using valves or by application of pressure. A fixed volume of inject fluid is injected into the destination stream by pressurizing the inject fluid in the chamber and opening an inject valve which connects the chamber to the destination stream. The pressurization of the inject fluid in the chamber above the destination stream pressure is effected by a T-valve which controls the flow of a purge fluid into the chamber. The purge fluid emitted by the T-valve flows toward the inject valve, forming a fluid-lock which establishes the fixed-volume to be injected. During the injection, the inject fluid is driven by the purge fluid pressure to flow through the inject valve into a destination passage which communicates with the destination stream. The inject fluid in the section of chamber between the T-valve orifice and the inject valve orifice is injected, as the purge fluid emitted at the T-valve displaces the inject fluid from that section…