Fluid metering apparatus

• US 6,202,679 B1
• Filed: 04/15/1999
• Issued: 03/20/2001
• Est. Priority Date: 12/01/1995
• Status: Expired due to Fees

• Current Assignee: Perception, Inc. (Pelican International Incorporated)
• Original Assignee: Perception, Inc. (Pelican International Incorporated)
• Inventors: Titus, John S.
• Primary Examiner(s): Michalsky, Gerald A.
• Application Number:
  US09/292,144
• Time in Patent Office: 705 Days
• Field of Search: 137/487.5, 137/557
• US Class Current: 137/487.5
• CPC Class Codes: G01F 1/34 by measuring pressure or differential pressure
• CPC Class Codes: G05D 7/0664 the plurality of throttling means being arranged for the control of a plurality of diverging flows from a single flow G05D7/0652 takes precedence; ratio control G05D11/13
• CPC Class Codes: Y10T 137/776 Control by pressures across flow line valve
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve
• CPC Class Codes: Y10T 137/8158 With indicator, register, recorder, alarm or inspection means
• CPC Class Codes: Y10T 137/8326 Fluid pressure responsive indicator, recorder or alarm

Abstract

A method and apparatus are described for controlling demand of a fluid. The method includes measuring a fluid supply pressure in a supply pipe, determining that the fluid supply pressure is lower than a predetermined threshold supply pressure, and directing a control signal from the fluid information unit to the one or more demand control units to reduce demand for the fluid. In addition, a method and apparatus are described for measuring density of a fluid flowing through a demand pipe. The method includes determining that fluid flow through the demand pipe is stable, measuring fluid flow rate through the demand pipe, preventing the fluid from flowing into the demand pipe for a sample period of time, measuring a drop in fluid pressure in the demand pipe during the sample period, and determining the density from the measured pressure drop. Also, a utility meter for metering a fluid flowing through a supply pipe and a demand pipe having an audible indicator to provide an audible signal to a user is described.

Claims

1. An apparatus for measuring density of a fluid flowing through a demand pipe, comprising:

a fluid dispensing unit including a controllable valve couplable to an inlet of the demand pipe; and

a fluid information unit including

a demand pressure sensor for sensing a demand fluid pressure of the fluid in the demand pipe,

a first communication channel between the fluid information unit and the controllable valve of the fluid dispensing unit,

a processor, coupled to the demand pressure sensor and the controllable valve, for controlling the controllable valve between a closed and an open position to regulate the fluid flowing through the controllable valve and configured to calculate a relative density of the fluid flowing through the controllable valve based, at least in part, on a pressure measurement signal received from the demand pressure sensor.

2. An apparatus as recited in claim 1, further comprising a temperature sensor disposed to detect temperature of the fluid in the demand pipe, the temperature sensor being connected to the processor to deliver temperature signals thereto.

3. An apparatus as recited in claim 1, wherein the processor includes a memory to hold data relating fluid flow rates, demand pressure differences and relative fluid density.

4. An apparatus as recited in claim 1, wherein the processor further includes a second communication channel connectable to a central station to download data thereto.

5. An apparatus as recited in claim 1, wherein the processor closes the controllable valve for a sampling time period, and the demand pressure sensor detects the pressure of the fluid at the beginning and the end of the sample time period.

6. An apparatus as recited in claim 1, wherein the fluid dispensing unit further includes a supply pressure sensor disposed to detect supply pressure of the fluid supplied to the controllable valve, the first communication channel is connected to the supply pressure sensor and the processor is coupled to the supply pressure sensor.

7. An apparatus for managing flow of a fluid flowing through a supply pipe and a demand pipe to at least one appliance having a demand control unit, comprising:

a supply pressure sensor disposed to measure a fluid supply pressure in the supply pipe; and

a fluid information unit connectable to the demand control unit, the fluid information unit including

a demand pressure sensor disposed to sense a fluid demand pressure in the demand pipe,

a communications channel connected to the supply pressure sensor, and

a processor, coupled to the supply and demand pressure sensors and couplable to the demand control unit to transmit a control signal to reduce fluid demand in response to a measured supply pressure falling below a predetermined supply threshold level.

8. An apparatus as recited in claim 7, wherein the processor is adapted to select a control signal in response to an amount by which the supply pressure is lower than the supply threshold level.

9. An apparatus as claimed in claim 7, the fluid information unit further including a communication interface connectable to a central station, wherein the processor is adapted to transmit a notification signal through the communication interface to the central station in response to transmission of the control signal.

10. An apparatus as claimed in claim 7, wherein the fluid information unit further includes a memory connected to the processor to store data on control signal transmission.

11. An apparatus as claimed in claim 7, wherein the fluid information unit further includes a loudspeaker connected to the processor to deliver audible signals to the user.

12. An apparatus as claimed in claim 11, further comprising a switch connected to the processor, activatable by a user to instruct the processor to deliver audibly via the loudspeaker.