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Metered Nozzle

IP.com Disclosure Number: IPCOM000084215D
Original Publication Date: 1975-Oct-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Mulzet, AP: AUTHOR

Abstract

Nozzle 10 dispenses metered amounts of fluid. It is particularly useful for dispensing liquid reagents, which may be of the corrosive type, into a specimen to be analyzed.

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Metered Nozzle

Nozzle 10 dispenses metered amounts of fluid. It is particularly useful for dispensing liquid reagents, which may be of the corrosive type, into a specimen to be analyzed.

Outer member 11 has an elongated cylindrical bore or cavity 12 with a cross- sectional radius R. Member 11 is fabricated from a noncorrosive plastic. A jewel nozzle tip 13 is shrunk fit into a compatible opening 14 formed at the discharge end of member 11. A concave depression 15 of radius R is provided in tip 13 adjacent to the entrance side of orifice 16. The apex of a conical depression 17 is provided in tip 13 adjacent to the discharge side of orifice 16.

By judiciously selecting the edge conditions of orifice 16, i.e., providing a predetermined round or smooth edge for orifice 16, it can be shown that the flow rate of nozzle 10 is independent of surface tension and viscosity of the fluid, and is inversely proportional to the square root of the fluid density. Thus, the flow rate of nozzle 10 is predictable for a wide variety of fluids with different known density characteristics.

The radius R of the cavity 12 is judiciously minimized, in the portion 11 of nozzle 10 upstream of orifice 16 and a curvature of compatible radius R is provided in depression 15, so that any air bubble introduced into the fluid stream, cf. arrow A, passes quickly through orifice 16 without substantially affecting the flow rate. That is to say, nozzle 10 has rapid self-priming characteristics.

When th...