Measuring and testing – Liquid level or depth gauge
Reexamination Certificate
2000-03-17
2002-04-02
Noland, Thomas P. (Department: 2856)
Measuring and testing
Liquid level or depth gauge
C073S001730
Reexamination Certificate
active
06363783
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
None
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not applicable.
BACKGROUND OF THE INVENTION
The present invention relates generally to the measurement of the amount of liquid contained in a tank and more particularly to measuring such amount while such tank is subject to dynamic forces that cause the liquid to slosh about the tank. More specifically, such liquid can be fuel in a fuel tank mounted on a motorized vehicle (e.g., aircraft, race car, etc.) where knowledge of the amount of fuel in the tank is important, or hazardous material being transported in a sealed container where leakage detection is required. In particular, there is a requirement for the operator to know precisely the ultimate amount of fuel in the fuel tank.
In the automobile racecar environment, the racecar, and hence its fuel tank or fuel cell, is subject to tremendous dynamic forces especially during turns. Measurement of the amount of fuel in the fuel cell becomes problematic at best, especially when the fuel is near exhaustion. The driver, as well as the race team manager, need to precisely know how much fuel actually remains in the fuel cell so that pit stops can be managed and the car does not run out of fuel. Conventional fuel cell sensor systems leave a great deal to be desired in this regard. Although not as time sensitive, operators of ordinary passenger automobiles also require knowledge of the amount of fuel remaining. In a more critical situation, the operator of an aircraft even more so needs to know when the fuel tank is almost empty and precisely how much fuel remains as the fuel nears exhaustion (i.e., ultimate amount of fuel).
In a different context, hazardous liquids often are required to be transported by truck, rail, or other means of transportation. During such transportation, the operation needs to be made aware of any leaks that develop from this storage tank while it is in motion. During transit, however, the hazardous liquids will be subject to dynamic forces of movement that make precise measurement of unexpected leaks very difficult to determine.
Thus, there exists a need to measure the amount of liquid housed within a storage container therefor when the container is subject to dynamic forces that cause the fuel level to fluctuate and make its measurement difficult. Heretofore, U.S. Pat. No. 1,233,065 proposes a gasoline gage mounted on the dashboard of a motor vehicle consisting of an isolation tube for a fuel level sensor, with a bottom-level opening for admitting fuel and a headspace outlet.
U.S. Pat. No. 3,417,613 proposes an immersed tube level indicator in automobile vehicles with an isolation tube containing a floating fuel level sensor. The tube also has a small opening at its lower for the feeding of fuel and at its upper end for venting. The sensor type used with the device is a float type.
U.S. Pat. No. 4,702,107 proposes a device for detecting the level of fuel contained within a tank. An isolation tube with a bottom inlet and headspace outlet houses a sensor consisting of a combined vertical bar with a printed circuit board and a float.
U.S. Pat. No. 5,687,607 proposes a device for measuring the quantity of fuel in a space vehicle. The device consists of an isolation tube located either inside or outside the fuel tank with a bottom inlet and headspace outlet. The sensor located within is preferably the capacitive method.
While these proposals are adequate for some purposes, they leave much room for improvement.
BRIEF SUMMARY OF THE INVENTION
Determination is made of the amount of liquid housed within a vessel subject to intermittent dynamic forces wherein the liquid in said vessel possibly is being discharged intermittently. The fluid in the vessel has a liquid level above which is a vessel headspace. A sensing tube of substantially less volume than said vessel is provided. This tube also is subject to the intermittent dynamic forces. If the tube and vessel have headspace not occupied by fluid, such headspaces are held at the same pressure, e.g., atmospheric pressure. The sensing tube is fitted with a sensor assembly for measuring the level of liquid therein. The tube is in fluid communication with the vessel through an orifice in the vessel whereby the fluid level in the vessel is the same as the fluid level in the tube. The size of the orifice is such that the tube fluid level measured by the sensor assembly is substantially unaffected by the intermittent dynamic forces.
Desirably, the tube is centrally located within the vessel and close to the bottom of the vessel. Further, is desirable that the tube be symmetrical in shape, e.g., cylindrical, square, or other such shape. Such features enhance the accuracy of the tube and response rate of the tube in measuring the ultimate amount of liquid remaining in the vessel or the initial discharge of liquid from the vessel.
A further aspect of the present invention is a method for calibrating an orifice of a sensing tube having an orifice, wherein the orifice is in fluid communication with liquid housed within a vessel whereby the fluid level in the vessel is the same as the fluid level in the sensing tube. The sensing tube is fitted with a sensor assembly for measuring the level of liquid in the sensing tube. The sensor assembly is connected to a read-out monitor. The vessel and the tube are subject to intermittent dynamic forces and the liquid in the vessel may be discharged intermittently. This method correlates the size of the tube orifice to the fluid properties of the liquid housed in the vessel, whereby the size of the orifice is such that the tube liquid level measured by the sensor assembly is substantially unaffected by the intermittent dynamic forces.
Advantages of the present invention include the ability to accurately measure the amount of liquid housed within a vessel easily and quickly regardless of whether the vessel is at rest or is subject to disturbing dynamic forces. Another advantage is that such liquid measurement capability can be easily retrofitted to existing vessels. A further advantage is that such liquid measurement is simple in construction and easy to operate. These and other advantages will become readily apparent to those skilled in the art based upon the instant disclosure.
REFERENCES:
patent: 11030 (1854-06-01), Clark
patent: 1233065 (1917-07-01), Kritzer
patent: 2031644 (1936-02-01), Gunderson
patent: 2237461 (1941-04-01), Tokheim
patent: 2619620 (1952-11-01), Tapp et al.
patent: 3181342 (1965-05-01), Barengoltz
patent: 3389602 (1968-06-01), Clemens
patent: 3396470 (1968-08-01), Wood
patent: 3417613 (1968-12-01), Barnstorf
patent: 4095476 (1978-06-01), Banon
patent: 4702107 (1987-10-01), Guerrini et al.
patent: 4882925 (1989-11-01), Brown
patent: 5687607 (1997-11-01), Brandt et al.
patent: 2244536 (1973-04-01), None
patent: 2924556 (1981-01-01), None
patent: 286219 (1991-01-01), None
patent: 310298 (1989-04-01), None
patent: 509784 (1976-09-01), None
patent: 62-235528 (1987-10-01), None
Halliday Donald R.
Turner Randy Lee
Hal-Tech, LTD
Mueller and Smith LPA
Noland Thomas P.
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