Fluid metering method

• US 6,076,542 A
• Filed: 07/13/1999
• Issued: 06/20/2000
• 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:
  US09/351,655
• Time in Patent Office: 343 Days
• Field of Search: 137/14, 137/487.5, 137/557
• US Class Current: 137/14
• 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 137/0396 Involving pressure control
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve
• 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. A method of controlling demand of a fluid using a fluid information unit connectable to at least one appliance demand control unit, comprising:

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 at least one appliance demand control unit to reduce demand for the fluid.

2. A method as recited in claim 1, wherein determining that the fluid supply pressure is lower than a predetermined threshold supply pressure includes determining a difference between the supply pressure and the demand pressure.

3. A method as recited in claim 1, wherein directing a control signal includes selecting a group of at least one appliance demand control unit to receive the control signal in response to an amount by which the supply pressure is lower than the threshold pressure.

4. A method as recited in claim 1, wherein directing a control signal includes determining whether a first flag has been set to indicate that a load from appliances in a first priority set has been reduced and, when it has been determined that the first flag has not been set, reducing the load from appliances in the first priority set and setting the first flag.

5. A method as recited in claim 1, further comprising determining whether a second flag has been set to indicate that a load from appliances in a second priority set has been reduced when the it has been determined that the first flag has been set.

6. A method as claimed in claim 1, further comprising notifying a central station that the control signal has been directed to the at least one appliance demand control unit.

7. A method as claimed in claim 1, further comprising storing information in a memory that the control signal has been directed to the at least one appliance demand control unit.

8. method as claimed in claim 1, further comprising providing an audible warning to a user that a control signal has been directed to the at least one appliance demand control unit to reduce demand for the fluid.