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WO1986003043A1 - Detecteur d'eau pour systemes de carburants et procede de detection d'eau dans ces systemes - Google Patents

Detecteur d'eau pour systemes de carburants et procede de detection d'eau dans ces systemes Download PDF

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Publication number
WO1986003043A1
WO1986003043A1 PCT/US1985/002192 US8502192W WO8603043A1 WO 1986003043 A1 WO1986003043 A1 WO 1986003043A1 US 8502192 W US8502192 W US 8502192W WO 8603043 A1 WO8603043 A1 WO 8603043A1
Authority
WO
WIPO (PCT)
Prior art keywords
water
electrically conductive
probe
circuitry
detector apparatus
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US1985/002192
Other languages
English (en)
Inventor
Richard W. Brown
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Aquatrol Corp
Original Assignee
Aquatrol Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Aquatrol Corp filed Critical Aquatrol Corp
Publication of WO1986003043A1 publication Critical patent/WO1986003043A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D33/00—Controlling delivery of fuel or combustion-air, not otherwise provided for
    • F02D33/003—Controlling the feeding of liquid fuel from storage containers to carburettors or fuel-injection apparatus ; Failure or leakage prevention; Diagnosis or detection of failure; Arrangement of sensors in the fuel system; Electric wiring; Electrostatic discharge
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
    • G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
    • G01F23/24—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid
    • G01F23/241—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid for discrete levels
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
    • G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
    • G01F23/24—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid
    • G01F23/241—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid for discrete levels
    • G01F23/243—Schematic arrangements of probes combined with measuring circuits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
    • F02M37/0047—Layout or arrangement of systems for feeding fuel

Definitions

  • the present invention relates to a water detector apparatus for fuel systems and method for detecting water in such fuel systems. More par ⁇ ticularly, the present invention provides an apparatus and method for detecting water in the carburetor bowl, fuel sumps, gasgulator, water separators, etc. of a fuel system.
  • the present invention solves this problem and others.
  • the present invention relates to a water detector apparatus for fuel systems.
  • the water detec ⁇ tor apparatus includes an electrically conductive probe inserted into a fuel holding reservoir of the fuel system.
  • AC signal means is electrically interconnected to the probe for supplying an AC signal thereto.
  • the probe exhibits a resultant resistance when the AC signal is so applied.
  • the resultant resistance is indicative of the presence or absence of water in the fuel holding reservoir.
  • Circuitry means is electri ⁇ cally interconnected to the probe for comparing the resultant probe resistance with a known resistance, the circuitry means including an output means for providing an output signal representative of the resultant resistance of the probe.
  • Indicator means is electri ⁇ cally interconnected to the output means of the cir ⁇ cuitry means for receiving the output signal.
  • the indicator means is responsive to the output signal received, the indicator means having a first state indicative of the presence of water and a second state indicative of the absence of water.
  • the present invention further relates to a method for detecting water in fuel systems.
  • the method comprises applying an AC signal via an electrical interconnection to an electrically conductive probe inserted into a fuel holding reservoir of the fuel system, the probe exhibiting a resultant resistance when the AC signal is so applied, the resultant resistance being indicative of the presence or absence of water in the fuel holding reservoir.
  • the method further includes monitoring via an electrical intercon ⁇ nection the resultant resistance of the probe and com ⁇ paring the probe resistance with a known resistance.
  • An electrical signal representative of the resultant resistance of the probe is then output to an indicator via an electrical interconnection, the indicator being responsive to the output signal.
  • the indicator has a first state indicative of the presence of water and a second state indicative of the absence of water.
  • the present invention is particularly advan ⁇ tageous in that it provides a system to detect water in the carburetor bowl, fuel sumps, gasgulator, and other reservoirs of an aircraft fuel system.
  • the present invention has particular utility in aircraft fuel -3- systems where it is important to detect the presence of water before engine shutdown occurs, which * could be a life threatening situation.
  • a selector switch is utilized to enable switching between probes at different locations in the fuel system.
  • a test switch is provided such that the operation of the indi ⁇ cator means can be verified.
  • Still yet another embodiment provides for simultaneous monitoring of two or more reservoirs.
  • the present invention provides a water detec ⁇ tor apparatus which is fairly sensitive and relatively inexpensive to incorporate into a fuel system whether it be a new fuel system or an existing fuel system.
  • the present invention provides for detection of the presence of water, not necessarily the level of water.
  • the present invention is capable of detecting pockets of water in a flow of fuel or when the fuel is being agitated or unsettled.
  • Figure 1 is a diagramatic view of an embodi ⁇ ment of a water detector apparatus in accorance with the principles of the present invention
  • Figure 2 is a cross-sectional view of an embo- diment of a probe assembly utilized in the embodiment shown in Figure 1;
  • Figure 3 is a schematic of an embodiment of the detection circuitry of the embodiment shown in Figure 1;
  • Figure 4 is a diagramatic view of a fourteen lead dual inline plastic package containing the cir ⁇ cuitry generally shown in Figure 3, the external con ⁇ nector pins being numbered 1-14, wherein the presence or absence of water is determined by comparing the loaded probe resistance with an internal resistance;
  • Figure 5 is an alternate embodiment of a four ⁇ teen lead dual inline plastic package containing generally the circuitry shown in Figure 3, the external connector pins being numbered 1-14, wherein the pre- sence or absence of water is determined by comparing loaded probe resistance with an external resistance;
  • Figure 6 is a partial electrical block diagram/schematic of the embodiment shown in Figure 1;
  • Figure 7 is a diagramatic view of an alternate embodiment of the present invention providing for water detection at multiple locations in the fuel system
  • Figure 8 is a front elevational view of a front panel of the alternate embodiment shown in Figure 7;
  • Figure 9 is a schematic diagram of an alter ⁇ nate embodiment of the present invention which provides for simultaneous monitoring at two locations in the fuel system;
  • Figure 10 is a front elevational view of a front panel of the embodiment shown in Figure 9. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
  • the water detector apparatus includes a support housing 22, which in the embodiment shown is a printed circuit board supporting the necessary electronics. Electrically interconnected to the electronics of the circuit board 22 by an electrical lead 24 is an electrically conductive probe assembly 26 which is at least partially threaded into the interior of a reser ⁇ voir 28 of the fuel system.
  • the reservoir might be the carburetor bowl, fuel sump, gasgulator, water separator, etc. of the fuel system.
  • the electro ⁇ nics of the printed circuit board 22 are further inter ⁇ connected by an electrical lead 29 to an electrical ground ' 30 and by an electrical lead 31 to a power supply 32 such as the vehicle's battery.
  • the printed circuit board 22 is mounted behind a face place 34 which supports a green light-emitting diode (LED) 36 and a red light-emitting diode (LED) 38 as well as a button test switch 40 which when pressed lights the red LED 38 to verify its operation.
  • a preferred embo ⁇ diment of the electrically conductive probe assembly 26 includes a brass threaded male fitting 42 having a collar portion 42a and a threaded portion 42b extending into the reservoir and a threaded portion 42c extending externally of the reservoir.
  • the threaded male fitting 42 includes an aperture extending generally longitudi ⁇ nally thereof.
  • An electrically conductive cylindrical brass rod 44 having an insulating sleeve 49 con ⁇ centrically positioned on the outside thereof is fitted -6- into the aperture of the male fitting 42 so as to form a fluid tight seal • with the male fitting 42 and be generally flush with the male fitting 42 on an inside end 45 thereof and extend beyond an outside end 43 of the male fitting 42.
  • a hole is drilled into the electrically conductive brass rod 44 from an outside end 47 thereof which is adapted for receipt of a bare electrically conductive lead wire 46.
  • the lead wire 46 is suitably soldered onto the electrically conductive brass rod 44 and interconnected to a portion 24a of the electrical lead 24 which might be terminated with a male connector 48 to enable releasable attachment to the electrical lead 24 from the printed circuit board 22.
  • a threaded female fitting 52 is slideably posi- tioned over the outside end 47 of the electrically con ⁇ ductive brass rod 44 so as to enable the female fitting 52 to be threaded onto the threaded portion 42c of the male fitting.
  • Concentrically positioned about the electrically conductive brass rod 44 is a washer 50. The washer 50 provides a seal between the male fitting 42 and the electrically conductive rod 44 to assure that there is no leakage of fluid from the reservoir 28.
  • the male fitting 42 is electrically conductive, it will be appreciated that the male fitting 42 might be made of a thermo plastic or some other electrically nonconducting material thereby doing away with the need for the insu ⁇ lating sleeve 49. However, this type of fitting might be less resistive to fire.
  • Mounted on the printed circuit board of the preferred embodiment is a monolithic bipolar integrated circuit including fluid detection circuitry 100 as generally illustrated in Figure 3.
  • the fluid detection circuitry 100 includes four basic circuits; a voltage regulator circuit, an oscillator circuit, an oscillator level detector cir- cuit, and an output drive circuit, each circuit being generally designated by the broken lines 102, 104, 106 and 108, respectively.
  • the numerical values of the resistors and capacitors are indicated, the respective units being ohms and microfarads.
  • the voltage regulator circuit 102 includes a seven volt zenner diode 110 which establishes a fairly constant voltage for the transistor Q5 so as to set a stable Vcc for the circuit.
  • the oscillator circuit 104 includes transistors Q2 and 06 which act as a driver for transistor Ql. This multi vibrator circuit is driven by a connection across connector pins 5 and 7 via a .01 microfarad (uf) capacitor 118 as is generally illustrated in Figure 4 so as to alternately provide base drive for the tran ⁇ sistors Q2 and Q6 forming a square wave output at con ⁇ nector pin 6 at approximately 2500 Hz.
  • uf microfarad
  • the output of the oscillator circuitry 104 is fed through an 18k ohm resistor 114 to connector pin 8 and through an external connection to connector pin 9 via a .1 microfarad (uf) capacitor 116 as illustrated in Figure 4.
  • the probe 26 as illustrated in Figure 4 is connected to the connec ⁇ tor pin 9 through a fluid medium 27 to an electrical ground. As the current from the connector pin 9 to ground is increased decreasing resistance the voltage level to the base at transistor 3 and an emitter follower resistor (270 ohms) 120 is decreased turning off the transistor Q3 thereby allowing the transistor 4 to conduct.
  • a decoupling capacitor 122 intercon- necting connector pins 10 and 11 tends to stabilize the output of transistor Q4 thereby providing a bistable switch "on/off” action.
  • a decoupling capacitor 123 is also interconnected to the connector pin 12.
  • the out ⁇ put driver circuitry 108 provides a load driven output on connector pins 1 and 14. When the transistor Q4 is conducting or “on”, the transistors Q7 and Q8 are “off” thus allowing the output at the connector pins 1 and 14 to go high.
  • the integrated cir- cuit might be packaged in the fourteen lead dual inline plastic package 60 diagramatically illustrated in Figure 4.
  • the integrated circuit might be the ULN-2429A Fluid Detector sold by Sprague Products Company, North Adams, Massachusetts 01247.
  • the fluid detection circuitry is interconnected to a supply voltage Vcc of preferably ten to sixteen volts and most preferably twelve volts which is provided by the power supply 32.
  • the circuitry includes the oscillator circuitry 104 for driving the electrically conductive probe 26 with an AC signal so as to prevent plating problems or the like. Upon application of the AC signal the probe 26 exhibits a resultant resistance which is indicative of the presence or absence of water in the fuel holding reservoir.
  • the resultant resistance will depend on whether an electrically con ⁇ ductive fluid is sensed such as water with impurities therein or a non-conductive fluid such as fuel.
  • the resultant probe resistance is compared with an internal resistance as previously discussed and as generally illustrated in the embodiment of Figure 4 or an exter ⁇ nal resistance as generally illustrated in the alter ⁇ nate embodiment of Figure 5 wherein corresponding parts are designated by primed reference numerals.
  • the fluid detection system provides an output signal represen- tative of the resultant resistance of the electrically -9- conductive probe 26. In the case of the embodiment shown in Figure 4, the probe 26 is connected to the connector pin 9.
  • a decrease in resistance at probe 26 causes transistor Q3 to turn “off” thereby turning “on” transistor Q4 and “off” transistors Q7 and Q8 thus allowing the output at connector pins 1 and 14 to go high.
  • the probe 26 is replaced by an 18k ohm resistor 124 to ground at connector pin 9. Under normal conditions wherein there is no water present, this will cause the output at connector pins 1 and 14 to go high.
  • the output is typically a square wave signal which might be used with an LED, incandescent lamp, or loudspeaker.
  • the green LED 36 will be lit when a low output is provided and the red LED 38 will intermittently blink when a high output is provided by the integrated circuit.
  • the green LED 36 is associated with a resistor 69 and the red LED 38 is associated with a resistor 71.
  • the blinking is caused by use of conventional oscillator/driver cir ⁇ cuitry as generally referenced by reference numeral 70.
  • an integrated circuit having nomenclature 74C14 and being manufactured by National Semiconductor Corp., 2900 Semiconductor Drive, Santa Clara, California 95051 -10- might be utilized.
  • Each stage 70a,b,c of the integrated circuit acts as an invertor.
  • the 74C14 integrated circuit is used since it has a high hystere ⁇ sis.
  • the output of the last section 70c will be high thus keeping the red LED 38 "off”.
  • the output of the connector pins 1 and 14 go high so as to turn "off” the green LED 36.
  • the output of the last section 70c is driven low turning "on” the red LED 38.
  • the output of the first section is low, a discharge path is formed for a capacitor 126.
  • the output of the last section 70c switches “high” causing the red LED 38 to turn “off”.
  • a 330k ohm resistor 128 then charges the capacitor 126 and after approximately one-half second switches the out ⁇ put. In this manner the red LED 38 continues to flash until the probe resistance is increased.
  • a rotary selector switch 80 might be provided enabling detector apparatus to be switched between various ones of the probes 26 at differing locations in the fuel system and/or a test position wherein the function of the red LED 38 is verified.
  • an on-off switch 82 might be provided for selectively intercon ⁇ necting the detector apparatus to the power supply 32 with a fuse 84 being inserted in the line.
  • FIGs 9 and 10 This embodi ⁇ ment includes two integrated fluid detector circuits 130, 132 similar ' to the integrated circuit 60 illustrated in Figure 4, interconnected to two indepen- dent probes.
  • Each of the integrated fluid detector -11- circuits is in turn interconnected to oscillator/driver circuitry 150, 152 similar to the oscillator/driver circuitry 70.
  • the oscillator/driver circuitry 150, 152 might be included in a single integrated circuit, such as the IC 74C14.
  • the oscillator/driver circuitry each includes three sections 150a,b,c and 152a,b,c respectively, a 2.7 megaoh resistor 154, 156 respectively, a .1 microfarad capacitor 158, 160 respectively, and a Ik ohm resistor 162, 164 respectively, associated with the yellow LEDs 134, 136 respectively.
  • FIG. 10 Illustrated in Figure 10 is a front panel view of the embodiment shown in Figure 9.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Thermal Sciences (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)

Abstract

Un appareil détecteur d'eau (20) pour détecter de l'eau dans les différents réservoirs d'un système de carburant comprend un boîtier de support (22) qui contient le système électronique de commande. Une sonde (26) électriquement conductrice est électriquement connectée par un fil conducteur (24) au système électronique et est vissée au moins en partie à l'intérieur d'un réservoir (28) du système de carburant. Un oscillateur (58) est inclus dans le système électronique pour fournir un signal de courant alternatif à la sonde (26) électriquement conductrice. Le système comprend en outre des circuits pour comparer la résistance résultante de la sonde (26) électriquement conductrice avec une résistance connue et pour furnir un signal de sortie représentant la résistance de la sonde (26) électriquement conductrice. Une diode électroluminescente verte (36) est électriquement connectée à la sortie de façon à s'allumer lorsque la sortie est faible, en indiquant ainsi l'absence d'eau, et une diode électroluminescente rouge (38) est électriquement connectée à la sortie de façon à clignoter lorsqu'une sortie élevée est détectée, en indiquant ainsi la présence d'eau.
PCT/US1985/002192 1984-11-08 1985-11-05 Detecteur d'eau pour systemes de carburants et procede de detection d'eau dans ces systemes Ceased WO1986003043A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US66961584A 1984-11-08 1984-11-08
US669,615 1984-11-08

Publications (1)

Publication Number Publication Date
WO1986003043A1 true WO1986003043A1 (fr) 1986-05-22

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PCT/US1985/002192 Ceased WO1986003043A1 (fr) 1984-11-08 1985-11-05 Detecteur d'eau pour systemes de carburants et procede de detection d'eau dans ces systemes

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EP (1) EP0203941A1 (fr)
AU (1) AU5060185A (fr)
WO (1) WO1986003043A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8268629B2 (en) * 2005-06-21 2012-09-18 dTEC Systems L.L.C. Method for the measurement of water and water-soluble components in non-aqueous liquids
WO2016176695A1 (fr) * 2015-04-30 2016-11-03 Chow Christopher Kai Ching Détecteur d'eau électronique pour un combustible hydrocarboné
US12298167B2 (en) 2020-11-01 2025-05-13 Franklin Fueling Systems, Llc Low level water sensor and method of use

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3793586A (en) * 1971-12-08 1974-02-19 Micador Electronics Pty Ltd Apparatus for detecting the presence of water in aircraft fuel tanks
US4410885A (en) * 1981-12-23 1983-10-18 Stenstrom Stephen M Conductive fluid detecting method and apparatus
US4488970A (en) * 1981-10-14 1984-12-18 Clark Joseph H Diesel fuel monitor system, negative pressure type

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3793586A (en) * 1971-12-08 1974-02-19 Micador Electronics Pty Ltd Apparatus for detecting the presence of water in aircraft fuel tanks
US4488970A (en) * 1981-10-14 1984-12-18 Clark Joseph H Diesel fuel monitor system, negative pressure type
US4410885A (en) * 1981-12-23 1983-10-18 Stenstrom Stephen M Conductive fluid detecting method and apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Electrical Design News; Vol. 24 # 14; 05 August 1979; "Technology News"; pg 48 figure 3, and pg. 53. *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8268629B2 (en) * 2005-06-21 2012-09-18 dTEC Systems L.L.C. Method for the measurement of water and water-soluble components in non-aqueous liquids
WO2016176695A1 (fr) * 2015-04-30 2016-11-03 Chow Christopher Kai Ching Détecteur d'eau électronique pour un combustible hydrocarboné
US12298167B2 (en) 2020-11-01 2025-05-13 Franklin Fueling Systems, Llc Low level water sensor and method of use

Also Published As

Publication number Publication date
AU5060185A (en) 1986-06-03
EP0203941A1 (fr) 1986-12-10

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