US 2910940 A
Description (OCR text may contain errors)
Nov. 3, 1959 H. coLMAN ETAL COMBINED FLUID PUMP AND INDICATOR Filed Nov 22, 1954 R u. D 5 n Am ,www1
I., mm R w nited States PatentY COMBINED FLUID PUMP AND INDICATOR l Harry Colman, Ormond, near Melbourne, Victoria, and Raymond Lawrence Fowler, Pascoe Vale South, near Melbourne, Victoria, Australia Application November 22, 1954, Serial No. 470,466
Claims priority, application Australia December 4,1953
2 Claims. (Cl. 10S-1) This invention relates to a methodof and means for indicating the presence of water in petrol tanks and it refers particularly to means for indicating the presence of water in underground petrol tanks (such as are customarily installed at garages, airports and other locations) and in other petrol tanks where the contents are not normally visible.
Itis commonly known that water does collect in petrol tanks, particularly in underground petrol tanks. Such` water as does collect in a petrol tank remains at the bottom of the tank and the volume of water in said tank gradually increases, duc largely to condensation of moisture from the air. `As a result, it is generally considered necessary to have the outlet opening of the petrol tank located a distancel above the bottom of the tank; so that the petrol drawn from the tank will be free of Water. But the presence of such water at the bottom of a petrol tank has serious disadvantages and it is generally considered advisable, especially when the petrol is to be used in aircraft, to clear out any water from a' petrol tank as soon at it collects.
Furthermore, water sometimes collects in the petrol tanks of aircraft-either from condensation or as a ref; sult of being pumped into the aircraft petrol tank with petrol from a tanker. The presence of ,water in an aircraft petrol tank can have very serious results, and" in the past it has been the cause of many serious accidents.
It has` been well' known for many years that the located in the tank due to changes in the liquid between 2,910,946 Patented Nov. 3, 1959 r; 2 And another object is to provide means for detecting the presence of water in a petrol tank or container and for ejecting the accumulated water from the container; `The in-vention devised with these and other objects in View resides, broadly, in the provision of proximity relay apparatusresponsive to capacitance changes and a vsheathed cable, the cable being connected to one ter- (or the complementary member) will be indicated by the; proximity relay apparatus.
Y When the apparatus is to be installed in an underground, petrol tank the sheathed cable is connected to a sensing element and the proximity relay is also connected-electrically to the tank itself (if the tank be made of an electrical conducting material), or to a second element held in spaced relationship with the sensing element (if the tank be made of a non-conductor). The sensinggelement is so mounted that when fitted in an underground petrol tank the element is supported a relatively -short distance from the bottom of the tank. Further, there may be provided a support for the cable and/organy suitable mounting for the sensing element. Further,there may be employed any suitable electrical connectionsand, if required, any suitable electrical equipment for amplifying signals.
The electrical apparatus may be connected to pumping apparatus in such manner that when the presence of water is detected the pump apparatus will be set in operation to eject the accumulated water. Alternatively, there may be provided pumping apparatus operable independently when the presence of water is indicated.
' lIn order that the invention may be clearly understood and readily put into practical veffect we shall now describe, With reference to the accompanying drawings, a general form of the apparatus and several particular applications of the invention. In these drawings:
the terminals, the resistance of water or apetrol-water mixture ditering from that of petrol. However, this apparatus has not been acceptable for the reason that it, can prove to be dangerous, and the likelihood of spark-` ing-and consequent 'explosion of the petrol-is relatively high.
This invention'has'been devised particularly With the'` object of providing improved apparatus for use in detecting,and indicating, the presence of water inv petrol. A further object of the invention is to provide apparatus for the purpose stated which willb'e extremely elective and safe in operation, relatively economical to manufacture and to install, and of relatively simple construction. l i
Yet another object is to provide apparatusvfor the purpose stated which will be usable in'petrol tanks made of non-metallic material. A still further object is to devise apparatus usable for detecting, and indicating, 'the presence of water in suspension in,petrol, or the presence of water ina petrol pipeline. l
. Fig.kv l is `a diagrammatic illustration of apparatus according to the invention for detecting the presence of waterin a petrol tank;
Fig. 2 shows, in vertical cross-section, the sensing head in relation` to the bottom of a petrol tank;
Fig. 3 is a circuit diagram of the proximity relay;
' Fig. 4 depicts the connections for use when the apparatus isto be used for operating a motor or other apparatus;
Fig. 5 illustrates a form of apparatus made according to the invention and incorporating a hand pump;
Fig. 6 is a perspective view of the lower end of the apparatus illustrated in Fig. 5.
Referring initially to Figs. 1, 2, 3 and 4 the apparatus P for detecting the presence of water in a petrol tank 11 an kalternating current supply source, the terminals 15 and 16 for connection to the tank 11 and the probe-indicated generallyin Fig. l by the reference 17. When a shielded cable is used for connecting to the probe one end of the shield maybe connected to terminal 15 (the other end being earthed or connected to the tank 11) and the inner wire is connected to the terminal 16. The probe 17 comprises a sensing element 18 to which is connected a cable 19 covered with insulating material The element 18 isv located within a probe head 21 O having at its lower end a series of spaced lugs 22, and it is held in place, and insulated from the probe head 21, by a filling 23 of insulating material-as a synthetic resin or plastic insulating material.
The probe hea-d 21 is fastened to vone end of a length of tube 24 made of a conducting material, as a length of copper tube. The upper end portion of the probe head 21 is screw-threaded to receive a flare nut 25, and it is chamfered at 26. The lower end of the tube 24 is ared or swaged outwardly at 27 so that it is conveniently clamped between the chamfered end 26 of the probe head 21 and the tapered surface of the are nut 25.
Fastened to a manhole cover 28 mounted in the top of the tank 11 is an internally screw-threaded socket 29. A reduction bush 30, having an axial opening of such a size as to be adapted to receive neatly the upper end portion of the tube 24, is screwed into the socket 29. The upper end portion of the tube 24 is clamped firmly in the reduction bush 30 by means of a ring seal 31 and a bush 32 which is screwed into the upper end portion of the reduction bush 30, and the insulation-covered cable 19 is clamped firmly within the bush 32 by means of a second ring seal 33 and a nut 34, the latter being screwed into the upper end of the bush 32.
The probe head 21 is thus held in fixed relationship with the cover 28, and the cable 19 is securely held at its lower end and where it passes through the top of the tube 24. Thus, -there is no strain on the cable 19.
The tubef24 is of such a length thatthe sensing element 18 is held a short distance from the bottom of the tank 411. The lugs 22 act as locators to ensure that the sensing element 18 is held a desired distance from the bottom of the tank, the apparatus being set up with the lugs 22 in contact with the tank bottom.
When the apparatus is set up in the manner illustrated in Fig. l, with the sensing element 18'correctly located near the bottom of the tank, the -terminal 15` of the proximity relay apparatus connected to the tank 11 (either directly or by both the terminal 15 and the tank being earthed) and the terminal 16 connected to the cable 19, then any variation incapacitance between the sensing element .18 and the tank 11 will be indicated by the vcapacity-operated proximity relay apparatus within the box 12. Thus, if there be an accumulation of water-indicated by the reference 35e-in the petrol 36, the presence of the water between the element 18 and the bottom of `the tank will be indicated. l
The proximity relay apparatus has the circuit indicated in Fig. 3. The relay indicated by the reference 37vhas terminals 378, 39, 40 and 41, of which the terminals 38 and 39 may be connected to a motor for `driving a pump in such manner that when the relay is operative to indicate the presence of Water in the petrol the motor -will be set in operation to drive the pump so as to eject .the water from the vtank 11. The terminals 40, 41 may be connected to any suitable indicating means-as an electric light globe, or a buzzer. Alternatively, `the apparatus may be set up so that a pump will be shut olf when the presence of water is detected in the petrol. This will be donelwhen the apparatus is included in a pipe line throughwhich petrol is being fed to the petrol tank. n n y Referring now to Figs. and 6 the apparatus `depicted therein comprisesa tubular member 42 having aprobe head 21 fastened lto its lower end by means of theV nut 25. This probe head has lugs 22 at its lower end but whereas the sensing element in the construction previouslydescribed, is in the form of a disc, the vsensing element in this construction is in the form of a flat ring 43 fastened to, but insulated from, the probev head 21. Ther cable19 is secured to the outer surface of the member 42 and it fits through an opening provided in the nut 25, being secured at its lower end to the ring 43.
The opening 44 in the ring 43 permits flow of liquid to a pump plunger 45 of any suitable type.
This plunger 45 is fastened to one end of a rod 46 and a handle 47 is secured to the other end of that rod. Thus, the rod 46 may be moved vertically relative to the tubular member 42. An `outlet nozzle 48 is provided near the upper end of the tubular member 42 so thatliquid pumped upwardly through-.that member 42 by the operation of -thejpump plunger 45 may escape from within the member 42.
The vproximity relay apparatus 12 is mounted on a bracket '49 Vfastened 4to thetubular member 42 near its upper end and a handle 50 is connected to the bracket 49 so as to provide a convenient means of holding the apparatus.
The indicating and pump apparatus illustrated in Figs. 5 and 6 may be conveniently carried byan operator and used to test for the presence of water in petrol containersas 44 gallon drums-and to eject water which may have accumulated'in such containers.
It isto beV noted that in this apparatus the tubular member 42 will be connected to the terminal 15 of the apparatus I12 Vand when the-apparatus is in use the lugs 22 at the lend of the probe head 21,- in making contact with the the interior of the tubular member 42, wherein i'sttcd 75 bottom ofthe container, will alsoeifect the electrical connectionof the apparatus 12 to 'the petrol container.
'If desired, a'spacin'g member may be adjustably tted tothe lower end of the probe head 21 so that the distance between the sensing element 18 and the bottom of the petrol tank 11, when the apparatus is fitted in position, may be adjusted -to suit Vany particular requirements. We have found that a distance of 1/2" between the sensing element and the bottom of the'tank is suitable for most purposes. l
[,In another -embodiment of thejinvention two sensing elements aretted kto the lsame pipe, so that they are spaced ashort distanceapart The terminals 1,5, 16 of the ,proximity relay apparatus are then connected to the two sensing elements. This apparatus vmay be mounted so .that the two sensing elements are a suitable distanceV from the bottom of the tank. The device vmay then be used to detect water suspended in the petrol, as it has been foundthat suspended water provides .a sucient changelinfdielectric vconstant to operate the level control unit. l
In another embodiment of the invention two sensing elements are mounted in a pipe or hose which is `used in the delivery of the petrol from the tank, so as to indicate the presence of water in the petrol flowing through the pipe or hose. a
The device has beenfound sulitable for use in the detection of water or other foreign substances in other media, such as kerosene or white spirit, and hence the word .petrol should be taken to include all petroleum products, and the term water to include yall such foreign substances of dielectric constant appreciably differ'- ent fromthat of petrol It is to be noted-that Vin the form :of the invention illustrated in Fig. 2 the sensing element 18` is provided with a lcovering of insulating material. This is doneto reduce the risk of tire due to an insulation failure in the external circuit, which failure could cause a spark be'- tween the element'andthe tank.
`If apparatus according to the invention be incorporated in a tank at a location whereat the electricity supply is not at,y the normal A.C. mains voltage, then it may be necessaryto modify the apparatus. For example, if it be desiredto build water detection apparatus into the petrol tanks of aircraft, then the capacity operated relay devices will have'to bemodied to make them suitable for operation on'direct current-from the aircraft supply systemand there will be incorporated in the circuit from the valve of the capacity operated relay devices to the solenoid type relay a current amplifying valve of standard type so as to provide fora sufficiently high value of current. A single sensing element may be used if the tank be of inetal, but if the tank be non-metallic on the inside then two sensing elements vwill be required, one connected to the plate *or the lgrid of the oscillator valve and the other to the cathode circuit.
It will be appreciated that the manner of installing the apparatus in a petrol tank will depend largely upon the nature of the tank and upon the locationthereof. All such modifications are to be deemed to be included Within the ambit of the invention.
What We claim is:
1. Apparatus for detecting the presence of water in petrol including a petrol tank, proximity relay means responsive to capacitance changes and having an earth terminal and an active terminal, the earth terminal being connected electrically to the bottom of the tank, a pump including a cylinder projecting into the tank, said pump having an outlet near its upper end and an inlet near the lower end, a piston adapted to draw water upwardly within the cylinder and to expel it through such outlet, a probe housing at the lower end of the cylinder, a probe mounted in said housing and electrically insulated therefrom, lugs projecting from the lower end of the probe housing to contact the bottom of the tank, the thus mounted probe thereby being held a short distance above the bottom of the tank, and an electrical connection between the active terminal and the probe, the proximity relay means being adapted to detect water in the lower portion of the tank and the pump being operable to expel the same.
2. Apparatus for fdetecting the presence of water in petrol including a petrol tank, proximity relay apparatus responsive to capacitance changes and having an earth terminal and an active terminal, the earth terminal being connected electrically to the bottom Iof the tank, a probe housing mounted Within thev tank at the lower end of a pump, the pump having a cylinder to which the probe housing is tted, an outlet near the upper end of the cylinder, an inlet near the lower end of the cylinder, and a piston adapted to draw water upwardly from the lower end of the cylinder and to expel it through that outlet, a probe mounted in the probe housing and electrically insulated therefrom, lugs projecting from the lower end of the probe housing into contact with the bottom of the tank so that the probe is spaced a set distance from the bottom, and an electrical connection between the active terminal and the probe, the apparatus being so arranged that the proximity relay apparatus is adapted to indicate variations in dielectric constant of the material in the tank between the probe and the bottom of the tank.
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