Instrumentation and control system and method for fluid transport and processing

• US 4,546,649 A
• Filed: 09/27/1982
• Issued: 10/15/1985
• Est. Priority Date: 09/27/1982
• Status: Expired due to Fees

• Current Assignee: Frederick W. Kantor
• Original Assignee: Frederick W. Kantor
• Inventors: Kantor, Frederick W.
• Primary Examiner(s): Frankfort, Charles
• Assistant Examiner(s): Will, Thomas B.
• Application Number:
  US06/423,570
• Time in Patent Office: 1,114 Days
• Field of Search: 340/870.11, 340/870.19, 340/825.21, 73/168, 73/730, 73/726, 370/100
• US Class Current: 73/168
• CPC Class Codes: G01B 7/06 for measuring thickness measuring during the manufacture of coatings C23C14/54
• CPC Class Codes: G01B 7/26 for measuring depth
• CPC Class Codes: G01F 1/002 wherein the flow is in an open channel
• CPC Class Codes: G08C 15/12 the signals being represented by pulse characteristics in transmission link

Abstract

A system and method for measuring and controlling the parameters and conditions of a thin-wall submersed-tube fluid transport system called an "equiduct" system. The tube or tubes preferably are located near the bottom of a water artery such as a river, and are in fluid equilibrium with the surrounding water. This permits the tubes to have relatively thin, flexible walls, which makes the tubes relatively inexpensive and easy to install. Simple pumps cooperate with the slope of the river bed in pumping fluids through the tubes. Parameters such as fluid pressures and velocities, depth, gas and liquid concentrations, etc. are measured at spaced locations in the tubes, and the measurements are delivered to a central data processing and control station so that the parameters can be adjusted, or the need for repairs in the tubes can be detected and the repairs can be made. Preferably, in a long equiduct system, the data from separate measurement stations along the system, are transmitted over a common communication line to the central station. A clock source transmits a series of digital identification words with blank spaces after the identification words. When each station detects its identification signal, it fills the subsequent blank space with data, which then is carried to the central station.

Claims

1. In an elongated data transmission system having a plurality of measurement stations spaced along a transmission line, a monitoring station, means for communicating along said transmission line data collected at said measurement stations, means for inserting measurement information from each of said measurement stations into said transmission line, and means in said monitoring station for receiving said information, wherein the transmission line has a speed of propagation and a length such that the delay time to said monitoring station from the most remote of said measurement stations is significantly longer than the time required for each measurement information inserting means to insert said information into said transmission line;

the improvement wherein said communicating means includes a sampling signal source for applying repetitive sampling signal bursts to said transmission line to travel past said measurement stations toward said monitoring station, each burst including a plurality of code-identified blank intervals, and means at each measurement station for detecting a selected one of said blank intervals in accordance with said code;

each said information measurement inserting means being operative to insert at least a portion of said information into the respective said one blank interval, such that the sampling rate at which said measuring stations can insert data and at which the monitoring station can receive said information from said measurement stations does not depend on the distance along said transmission but instead depends on the rate of repetition of the code-identified blank intervals of said sampling signal.

2. A system as in claim 1 including an equiduct system, said transmission line extending along said equiduct system, said measurement stations being positioned along said equiduct system to measure the parameters thereof.

3. A system as in claim 1 in which each of said bursts include a plurality of coded signals followed by said blank intervals, and means for repeating the bursts in a pre-determined sequence thereby repetitively sampling the data at said measurement stations.

4. A system as in claim 2 in which said measurement information is selected from the group consisting of measurements of equiduct depth, pressure across equiduct wall, fluid velocity, gas traction in fluid, gas composition, liquid composition stress or strain in equiduct wall, wall defects, leakage, surface waves, wall fatigue, pressure drop across pump, pump power operating temperatures, duct wall thickness, fluid density, and viscosity.

5. In combination, an equiduct system including at least one elongated conduit with a thin elastic wall submerged in a liquid and carrying a liquid in fluid equilibrium with the first-named liquid, strain gage means on the wall of said conduit for detecting the difference between the pressures inside and outside said conduit, and an elongated data transmission system having a plurality of measurement stations spaced along a transmission line, a monitoring station, means for communicating along said transmission line data collected at said measurement stations, means for inserting measurement information from each of said measurement stations into said transmission line, and means in said monitoring station for receiving said information, wherein the transmission line has a speed of propagation and a length such that the delay time to said monitoring station from the most remote of said measurement stations is significantly longer than the time required for each measurement information inserting means to insert said information into said transmission line;

the improvement wherein said communicating means includes a source of repetitive sampling signal bursts, each burst including a plurality of code-identified blank intervals, and means at each measurement station for detecting a selected one of said blank intervals in accordance with said code;

each said information measurement inserting means being operative to insert at least a portion of said information into the respective said one blank interval, such that the sampling rate at which said measuring stations can insert data and at which the monitoring station can receive said information from said measurement stations does not depend on the distance along said transmission line to said measurement stations but instead depends on the rate of repetition of the code-identified blank intervals of said sampling signal;

wherein said strain gage means includes means supplying the detected pressure difference to an associated one of said measurement information inserting means.

6. A device as in claim 5 in which said strain gage means includes a strain gage aligned to detect circumferential strain in said wall.

7. A device as in claim 5 in which said strain gage means includes a strain gage aligned to detect longitudinal strain in said wall.

8. A device as in claim 5 in which said strain gage means includes separate strain gages arranged, respectively, longitudinally, circumferentially, and at 45°

to the longitudinal axis of said conduit.

9. In an equiduct system including at least one elongated conduit with a thin elastic wall submerged in a liquid and carrying a liquid in fluid equilibrium with the first-named liquid, said wall being made of electrically insulating material, the improvement comprising an electrical potentiometer circuit including spaced electrical contacts contacting the liquid in said conduit and forming two electrodes of a potentiometer, the liquid impedances between a leak in the conduit wall and said contacts forming two resistances of said potentiometer, means for applying a voltage to said potentiometer and detecting the ratio of the voltages across said resistances to represent the distances of said contact from said leak, and an elongated data transmission system having a plurality of measurement stations spaced along a transmission line, a monitoring station, means for communicating along said transmission line data collected at said measurement stations, means for inserting measurement information from each of said measurement stations into said transmission line, and means in said monitoring station for receiving said information, wherein the transmission line has a speed of propagation and a length such that the delay time to said monitoring station from the most remote of said measurement stations is significantly longer than the time required for each measurement information inserting means to insert said information;

the improvement wherein said communicating means includes a sampling signal source for applying repetitive sampling signal bursts to said transmission line to travel past said measurement stations towards, each burst including a plurality of code-identified blank intervals, and means at each measurement station for detecting a selected one of said blank intervals in accordance with said code;

each said information measurement inserting means being operative to insert at least a portion of said information into the respective said one blank interval, such that the sampling rate at which said measuring stations can insert data and at which the monitoring station can receive successive elements of said information from said measurement stations does not depend on the distance along said transmission line to said measurement stations but instead depends on the rate of repetition of the code-identified blank intervals of said sampling signal;

wherein said means applying voltage and detecting the voltage ratio includes means supplying information, representing the distances from said leak, to an associated one of said measurement information inserting means.

10. A system as in claim 9 in which said resistances are connected as two arms of a bridge circuit, and a comparator for comparing the voltage between said leak and the bridge node opposite thereto.

11. A method employing an elongated data transmission system for measuring the pressure difference between the inside and outside of a equiduct, the elongated data transmission system having a plurality of measurement stations spaced along a transmission line, a monitoring station, means for communicating along said transmission line data collected at said measurement stations, means for inserting measurement information from each of said measurement stations into said transmission line, and means in said monitoring station for receiving said information, wherein the transmission line has a speed of propagation and a length such that the delay time to said monitoring station from the most remote of said measurement stations is significantly longer than the time required for each measurement information inserting means to insert said information into said transmission line;

wherein said communicating means includes a sampling signal source of for applying repetitive sampling signal bursts to said transmission line to travel past said measurement stations, each burst including a plurality of code-identified blank intervals, and means at each measurement station for detecting a selected one of said blank intervals in accordance with said code;

each said information measurement inserting means being operative to insert a least a portion of said information into the respective said one blank interval, such that the sampling rate at which said measuring stations can insert data and at which the monitoring station can receive successive elements of said information from said measurement stations does not depend on the distance along said transmission line to said measurement stations but instead depends on the rate of repetition of the code-identified blank intervals of said sampling signal;

said method comprising measuring the strain in the equiduct wall converting the resulting strain measurement to a pressure measurement, and supplying said pressure measurement to a respective one of said measurement information inserting means of said elongated data transmission system.

12. A method of measuring traveling waves in equiducts, said method comprising performing a pressure measurement as in claim 11, and detecting at least a longitudinal component of said strain.