High temperature coriolis mass flow rate meter

• US 4,876,898 A
• Filed: 10/13/1988
• Issued: 10/31/1989
• Est. Priority Date: 10/13/1988
• Status: Expired due to Term

• Current Assignee: Micro Motion Incorporated (Emerson Electric Company)
• Original Assignee: Micro Motion Incorporated (Emerson Electric Company)
• Inventors: Cage, Donald R., Van Cleve, Craig B.
• Primary Examiner(s): Goldstein, Herbert
• Application Number:
  US07/257,806
• Time in Patent Office: 383 Days
• Field of Search: 73/861.37, 73/861.38
• US Class Current: 73/861.355
• CPC Class Codes: G01F 1/8409 constructional details
• CPC Class Codes: G01F 1/8413 means for influencing the flowmeter's motional or vibrational behaviour, e.g., conduit support or fixing means, or conduit attachments
• CPC Class Codes: G01F 1/8422 exciters
• CPC Class Codes: G01F 1/8427 detectors
• CPC Class Codes: G01F 1/8477 with multiple measuring conduits

Abstract

Apparatus is disclosed for a Coriolis mass flow rate meter and specifically such a meter that is suited for operation at relatively high temperatures, such as in excess of approximately 500° F. (approximately 260° C.) and preferbly as high as 800° F. (approximately 427° C.), and that does not utilize a cooling purge.

Claims

1. A Coriolis mass flow meter, electrically connectable to processing means including means for providing a driver signal to said meter and to means for processing a deflection signal produced in said meter to provide an output representative of the mass flow rate of the fluid flow, said flow meter being capable of operating in a temperature range having a lower boundary in excess of 260 degrees C., comprising:

means for hermetically enclosing said flow meter;

an inert gas situated within said enclosing means;

flow conduit means, substantially insusceptible to carbide precipitation occurring in said temperature range, for receiving fluid therethrough whose mass flow rate is to be measured;

means for mounting said flow conduit;

high temperature driver means, responsive to said driver signal, for vibrating said flow conduit with respect to said mounting means;

high temperature sensor means for sensing the deflection of said flow conduit means caused by fluid flow through said flow conduit means and for producing said deflection signal representative of said deflection, said driver and said sensor means comprising;

a high temperature magnet means; and

a high temperature coil means;

terminal block means, having multiple conductors, mounted adjacent to said high temperature coil means and in a stationary relationship with respect to said enclosing means; and

high temperature flexure means, having one or more uninsulated electrical conductors, for electrically interconnecting said coil means of said driver means and said sensor means with said adjacent terminal block means, said flexure means dimensioned so as to form a U-shape when electrically interconnecting said coils with said conductors of said adjacent terminal block means;

feed-through means having multiple conductors therethrough for providing an hermetically sealed passage for routing signals through said enclosing means, said signals including said driver signals and said deflection signals from said driver means and said sensor means;

multiple internal insulated wiring leads for electrically interconnecting individual ones of said conductors of said terminal block means with corresponding internal ends of said individual conductors of said feedthrough means; and

multiple external insulated wiring leads for providing at least a portion of the electrical interconnection between individual ones of said conductors of said external ends of said individual conductors of said feed-through means and said processing means.

2. The apparatus of claim 1 wherein the conductors of said flexure consist essentially of nickel.

3. The apparatus of claim 1 wherein the conductors of said terminal block means consist essentially of nickel.

4. The apparatus of claim 1 wherein the internal insulated wiring leads each comprise:

a conductor consisting essentially of nickel; and

an annealed fiberglass sheath surrounding said conductor.

5. The apparatus of claim 1 wherein the external insulated wiring leads comprise:

individual conductors consisting essentially of nickel;

a layer of mica tape wrapped about each individual lead;

a woven fiberglass sheath for surrounding said mica tape wrapped wire having a pre-baked portion adjacent the end of said individual lead connected to said feed-through; and

a woven fiberglass sheath surrounding all of said wrapped and sheathed individual leads.

6. The apparatus of claim 1 wherein said coils comprise:

a hollow, cylindrical bobbin having metal wire posts and metal mounting inserts, said bobbin formed from an injection moldable ceramic material and having an annular opening therethrough along its longitudinal axis for receiving said magnet;

a coil matrix positioned about the exterior of said bobbin intermediate the ends thereof, said coil matrix comprising a multiple turn wire coil whose turns are separated from one another by a ceramic material and whose ends are electrically connected to said wire posts.

7. The apparatus of claim 6 wherein the metal wire is selected from a group consisting of gold, silver, and platinum.

8. The apparatus of claim 1 wherein the inert gas is selected from a group consisting of argon or helium.

9. The apparatus of claim 1 wherein the inert gas has a pressure that is less than atmospheric pressure.

10. The apparatus of claim 1 wherein the upper boundary of the temperature range is about 426°

degrees C.