US 5,487,313 A · Fluid-lock fixed-volume injector

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 of the chamber.

Claims32

Dependent claims

An injector assembly for injecting a fixed volume of a first fluid comprising:

a chamber for containing an amount of the first fluid, and having a first valve at one end to connect said chamber to a first fluid source, a portion of the chamber defining said fixed volume;
a second valve connected to the chamber at one end of the fixed-volume portion, thereby causing a second fluid stream from a second fluid source to flow into the fixed-volume portion and forcing the first fluid in the fixed-volume portion into a destination passage;
a third valve connected to the chamber at an end of the fixed-volume portion opposite said second valve, and communicating the fixed-volume portion to the destination passage;
and
a fourth valve connected to the chamber at an end opposite said first valve, thereby trapping the first fluid in the chamber.

2 more elements

An injector device for injecting a fixed volume of a first fluid into a destination stream composing:

a wafer-like substrate;
a first fluid groove formed in the substrate for containing the first fluid, a section of the first fluid groove defining said fixed volume;
a first valve, a seat of which is formed in the substrate, thereby passing the first fluid from a first fluid source therethrough into the first fluid groove;
a second valve, a seat of which is formed in the substrate, connected at one end of the fixed-volume section of the first fluid groove, thereby passing a second fluid into said fixed-volume section and forcing the first fluid in said fixed-volume section into a destination passage which communicates with the destination stream;
a third valve, a seat of which is formed in the substrate;
connected at an end of the fixed-volume section of the first fluid groove opposite said second valve, and communicating the fixed-volume section to the destination passage;
a fourth valve connected to the first fluid groove at an end opposite said first valve, thereby trapping the first fluid therein;
a first, inflexible layer overlying the portion of the substrate in which the first fluid groove is formed;
and
a second, flexible layer overlying the portion of the substrate in which the valve seats are formed, thereby serving as a diaphragm for each valve having a seat formed in the substrate.

7 more elements

An injector device for injecting a fixed volume of a first fluid into a destination stream comprising:

a wafer-like substrate;
a first fluid groove formed in the substrate for containing the first fluid, a section of the first fluid groove defining said fixed volume;
a first valve, a seat of which is formed in the substrate, thereby passing the first fluid from a first fluid source therethrough into the first fluid groove;
a second valve, a seat of which is formed in the substrate, connected at one end of the fixed-volume section of the first fluid groove, thereby passing a second fluid into said fixed-volume section and forcing the first fluid in said fixed-volume section into a destination passage which communicates with the destination stream;
a third valve, a seat of which is formed in the substrate, connected at an end of the fixed-volume section of the first fluid groove, and communicating the fixed-volume section to the destination passage;
wherein an end of the first fluid groove opposite said first valve is adapted to connect to a pressure source, thereby trapping the first fluid in the first fluid groove;
a first, inflexible layer overlying the portion of the substrate in which the first fluid groove is formed;
and
a second, flexible layer overlying the portion of the substrate in which the valve seats are formed, thereby serving as a diaphragm for each valve having a seat formed in the substrate.

6 more elements

A gas chromatograph system for analyzing a fixed volume of a first fluid, comprising:

a wafer-like substrate;
a first fluid groove formed in the substrate for containing the first fluid, a section of the first fluid groove defining said fixed volume;
a first valve, a seat of which is formed in the substrate, thereby passing the first fluid from a first fluid source therethrough into the first fluid groove;
a second valve, a seat of which is formed in the substrate, connected at one end of the fixed-volume section of the first fluid groove, thereby passing a second fluid into said fixed-volume section and forcing the first fluid in said fixed-volume section into a destination passage which communicates with the destination stream;
a third valve, a seat of which is formed in the substrate, connected at an end of the fixed-volume section of the first fluid groove opposite said second valve, and communicating the fixed-volume section to the destination passage;
a fourth valve connected to the first fluid groove at an end opposite said first valve, thereby trapping the first fluid therein;
a first, inflexible layer overlying the portion of the substrate in which the first fluid groove is formed;
a second, flexible layer overlying the portion of the substrate in which the valve seats are formed, thereby serving as a diaphragm for each valve having a seat formed in the substrate;
a third fluid source connected at an inlet to the destination passage, wherein a pressure of a third fluid stream from said third fluid source is less than a pressure of the second fluid stream;
an analytical column connected at an outlet of the destination passage;
and
a detector connected at an outlet of said analytical column.

9 more elements

Dependencies are inferred from the claim text.

Fluid-lock fixed-volume injector

Life of this patent

Fluid-lock fixed-volume injector

Life of this patent

Abstract

Claims32