Abstract: A microporous structure can be formed from ductile material such as glass into an axially extended outer wall surrounding a plurality of singular micro-passages surrounded by the outer wall to provide an open area that extends continuously over the length of the outer wall. The diameter of the micro-passages will usually not exceed 25 &mgr;m and are more in range of from 0.5 to 5 &mgr;m. The structure is particularly useful as frits for the containment of packing in capillaries for chromatograph applications and more generally as flow restrictors. Continuous open diameters of the micro-passages have a relatively straight flow path that reduces pressure drop relative to the random arrangement of other frits while still providing the desired containment.

Abstract: A microporous structure can be formed from ductile material such as glass into an axially extended outer wall surrounding a plurality of singular micro-passages surrounded by the outer wall to provide an open area that extends continuously over the length of the outer wall The diameter of the micro-passages will usually not exceed 25 &mgr;m and are more in range of from 0.5 to 5 &mgr;m. The structure is particularly useful as frits for the containment of packing in capillaries for chromatograph applications and more generally as flow restrictors. Continuous open diameters of the micro-passages have a relatively straight flow path that reduces pressure drop relative to the random arrangement of other frits while still providing the desired containment.

Abstract: A microporous structure can be formed from ductile material such as glass into an axially extended outer wall surrounding a plurality of singular micro-passages surrounded by the outer wall to provide an open area that extends continuously over the length of the outer wall. The diameter of the micro-passages will usually not exceed 25 &mgr;m and are more in range of from 0.5 to 5 &mgr;m. The structure is particularly useful as frits for the containment of packing in capillaries for chromatograph applications and more generally as flow restrictors. Continuous open diameters of the micro-passages have a relatively straight flow path that reduces pressure drop relative to the random arrangement of other frits while still providing the desired containment.

Abstract: A compound capillary can provide different sizes and configurations for central and outer passages to suit a variety of process applications, in particular methods of separative transport of multi-component samples and precise heat control of fluid streams on a micro scale. The compound capillary can be formed from ductile glass material into an assembly that typically provides a central passageway for retaining one fluid or material and single or multiple outer passages for retaining different fluids or materials. One or more of the different passages may also retain one more different stationary phase to tailor the separative transport to the material of particular sample streams. The compound capillary has particular application to the field of capillary electrophoresis where the multiple capillary passages in a single capillary tube may be used to increase sample through, or used for different function such as cooling and/or the establishment of transverse electrical potentials.

Abstract: A multi-passage capillary arrangement can be formed from ductile glass material into an assembly that has an essentially round outer cross section and multiple capillary passages with diameters of 250 micrometers or less. The multiple capillary assembly provides multiple capillary sized passages of a regularly recurring shape in a single cohesive bundle. The round outer cross section facilitates the use of the multiple capillary by providing a suitable surface for connections. The multiple capillary arrangement can be made by a method that provides uniform or nearly uniform capillary passages throughout the arrangement. The capillaries are useful for chromatograph applications and as flow restrictors.

Abstract: The present invention uses a flow restrictor in the form of a tube containing multiple capillary sized passages to minimize any discharge of toxic gases from compressed gas cylinders in the unlikely event of the control valve or regulator failure. The use of this arrangement to provide a flow restriction in combination with a regulator in the form of dispensing check valve provides a virtually fail safe system for preventing hazardous discharge of fluid from a pressurized cylinder or tank. The multiple capillary passage structure provides carefully sized openings that minimize any discharge of gas. Location of the inlet to the capillary tube at the midpoint of the cylinder can also prevent the discharge of liquid from the cylinder if the control valve system fails. Limiting the accidental discharge of fluid from the cylinder to gas phase fluids greatly reduces the uncontrolled mass flow rate at which fluid can escape from the cylinder.

Abstract: A new type of tubular assembly especially adaptable to capillary columns for use in gas chromatography, comprises a capillary wound on and fused to a hollow mandrel and stress relieved by heating. The entire assembly is rigid and is more resistant to fractures than prior available columns. Variants include rigid assemblies integral with heating means. Solid, brittle stationary phases can be readily accommodated in these assemblies because of their rigidity and structural strength.