US 3695095 A
An apparatus for measuring water impurities in oil comprises a confined space in which the oil is heated to a temperature higher than the evaporation temperature of water. In accordance with the invention, the confined space is a chamber arranged between an inlet and an outlet and having heating means and temperature control means, said chamber being adapted, by way of valves provided in the inlet and the outlet, to form a closed system. The chamber has an expansion vessel connected thereto, which is of variable volume and has means for emptying it. Further, the closed system is provided with means for measuring and/or controlling the change of state produced by the heating of the oil.
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Description (OCR text may contain errors)
United States Patent Lineberg [541 APPARATUS FOR MEASUING WATER IMPURITIES 1N OIL Inventor: Birger David Lineberg, Ekorrvaegen 7, Koping, Sweden Filed: April 14, 1970 App1.No.: 28,350
Int. Cl. ..Gln 11/00, GOln 33/28 Field of Search ..73/6l.l R, 61.3, 15 R  References Cited UNITED STATES PATENTS 3,511,083 5/1970 Reay et al. ..73/6l.l R 3,481,182 12/1969 Lineberg ..73/61.1 R 2,571,470 /1951 Milligan ..73/61.1 R
Oct. 3, 1972 ABSTRACT An apparatus for measuring water impurities in oil comprises a confined space in which the oil is heated to a temperature higher than the evaporation temperature of water. ln accordance with the invention, the confined space is a chamber arranged between an inlet and an outlet and having heating means and temperature control means, said chamber being adapted, by way-of valves provided in the inlet and the outlet, to form a closed system. The chamber has an expansion vessel connected thereto, which is of variable volume and has meansfor emptying it. Further, the closed system is provided with means for measuring and/or controlling the change of state produced by the heating of the oil.
r w n Kie llllll llll PATENTEU 3 3 6 95 O 95 APPARATUS FOR MEASUING WATER IMPURITIES IN OIL is also suited for the general determination of waterim-- purities lower than percent in oil or other liquid media which are not appreciably vaporized at ternpgratures lower than 150 to 170 C.
Water impurities in oil for example when the oil is used for quenching at hardening operations may produce explosive fires under unfavorable conditions in that the oil is wholly or partly heated to temperatures higher than 100 C, when very heavy vaporization takes place. The same risk exists when oil is used to transmit heat, as soon as the oil is heated to a temperature higher than 100 C. Critical water contents in these uses are of the order of 0.1 percent. Quenching in oil at hardening operations often takes place in an at mosphere containing int. al. H N and CO said gases being partly dissolved in the oil, which is not either suitable.
Water impurities in oil are also dangerous when the oil is to be used in electrical apparatus and for the lubrication of bearings and like means, for which reason it should be possible exactlyto determine the water content in all of these cases."An exact measuring of water impurities in oil is also necessary when the oil has been separated from e.g. waste water or from ballast water in ships tanks and the oil is either to be destroyed or purified. With oil separated from waste water supervision of the water content shall take place 'over a broad range, usually 0.1 to 5 percent. Also when the oil has been separated from ballast water the water content varies" considerably. In the cases where oil is used asa coolant with admixture of water, for instance in cutting operations, it is important to have the possibility of measuring the water content, since the cooling properties of the coolant oil are deteriorated if the water evaporates and the water content becomes too low. The respective water contents in this connection are in the order of 0.1 to 5 percent.
Whenever water impurities in oil involve the risk of accidents it is imperative to have a measuring apparatus which not only reliably measures the .water impurities but also is so designed that no measuring errors can occur or in any case cannot occur without an alarm being given that the apparatus is deficient in some way.
The above mentioned examples will show that there is a great demand for a reliable apparatus which permits measuring water impurities in oil, and to satisfy the requirements placed on such a measuring apparatus the present invention provides an apparatus of this kind which is characterized by the features that the confined space is a chamber arranged between an inlet and an outlet and having heating means and temperature control .means, said chamber forming a closed system by way of valves provided in the inlet and the outlet, that the chamber has an expansion vessel connected thereto, which is of variable volume and has means for emptying it, and that the closed system is provided with means for measuring and/or controlling the change of state produced by the heating of the oil.
The above and further features of the invention will become apparent from the following detailed description in which reference is made to the accompanying figure diagrammatically illustrating a preferred embodiment of a measuring apparatus.
A heat insulated chamber in which the oil is to be heated is generally designated 1. The chamber has an inlet 2 and an outlet 3. The chamber contains heating means and. temperature control means which preferably consist of a temperature controlled heating cartridge 4. An expansion vessel generally designated 5 -is in communication with the chamber 1 and is comprised as a unit in the confined space formed by the chamber 1, the room 6 of the expansion vessel which is totake up oil, and a buffer space, if any, which shall prevent hot oil from reaching the expansion vessel 5 and which may be in the form of a pipeline 7. The expansion vessel 5 is of such a design that the oil can be taken up therein without getting in contact with ambient air, and therefore the vessel may suitably be a cylinder 9 having a piston 8. By reason of the design of the expansion vessel the oil in the room 6 will primarily be under approximately atmospheric pressure. The piston 8 has a piston rod whiclf serves as guide means and an indicator for the movements of the piston, and besides the piston is operably means of compressed air or in some other manner for returning it to bottom position so that the room 6 can be emptied by the piston providing a pumping action. A
To realize a measuring cycle dissolved gases, if any, must first be removed from the oil as these may otherwise aifect the measuring result so that wrong values for the water impurities are obtained. Degasification 5 takes place by pumping oil into the measuring chamber l and the expansion vessel 5, the piston 8 reaching the top position b. l-l N and CO dissolved in the oil which gases show a lower solubility-at higher. temperatures than at lower temperatures as distinct from most other gases escape because of the elevated temperature which arises by cold oil being mixed with hot oil and by the oil being heated by the heating cartridge 4. These gases collect in a dome 11 at the top of the chamber 1, and part of the gases is conducted from said dome 11 to the outlet 3 when the piston 8 is pressed down to its intermediary position a. The force pressing the piston down is then removed so that the piston is capable of freely moving upwards until atmospheric pressure prevails in the system. Dissolved gas possibly remaining in the oil then escapes and collects in the dome 11. The downwardly directed force is again applied to the piston 8 which is pressed down into its bottom position 0, all of said gas being pressed out of the measuring system. When said latter downward pressing of the piston has been concluded, the downwardly directed force is again removed and atmospheric pressure can again prevail in the confined space, whereupon valves 12 and 13 in the inlet 2 and outlet 3 are closed.
The conditions for an exact measuring have now been attained, that is, a temperature lower than the evaporation temperature of water, a pressure approximately equal to atmospheric pressure, and oil free from disturbing insoluble gases, for which reason the measuring cycle proper can be initiated.
The measuring cycle is as follows: After the oil has thus been degasified and the valves 12 and 13 closed,
the temperature of the oil is elevated to a value higher than the evaporation temperature of water at the pressure prevailing in the confined system. This temperature is chosen with due regard. to the desired measuring exactitude and to the desired working pressure, said temperature usually varying between from about 110 to 130 C. As the oil is degasified before the temperature rises above 95 C and the oil has a relatively small content of gasifiable constituents, which is always a prerequisite when the oil is to be used at elevated temperatures, it is only the water occurring in the oil that can influence pressure or volume changes according to the general law of the state of gases at further heating. Should, however, the pressure or volume change be conditioned by light components in the oil it is equally essential that their presence be indicated as the presence of water, because such gases can occasion equally heavy damage as water.
At continued heating of the oil in the chamber 1 the volume of the oil increases and fills out the expansion vessel 5 to an extent which is constant since it is conditioned merely by the volume expansion coefficient. By reason of the expansion vessel having been designed as a cylinder 9 which a piston 8, said piston separates the measuring system from any external influence other than the atmospheric pressure and the frictional resistance of the piston, which becomes small and constant owing to' the lubricating and sealing properties of the oil. At the volume increase the piston normally moves to the intermediary position a. Should, however, water be present in the oil said water is evaporated and the volume increase will be greater than normal, for which reason the piston 8 continues to move to its top position b where a stop abutment for the piston movement may be disposed. Should further water be present in the oil the pressure in the measuring system begins to rise according to the general law of gases, and this pressure increase is easily measured by means of a pressure gauge 14 the deflection of which thus is a measure of the size of the water impurities in the oil. The volume of the cylinder and the permissible movements of the piston therefore determines the measuring range; a longer piston stroke or a larger cylinder being chosen at larger water impurities. Therefore several cylinders can be connected to the same measuring system via different valves, and water contents from about 0.01 percent to more than 1 percent can be measured with the desired exactitude.
After a finished measuring cycle the oil is pumped by the pump 15 under a pressure that by reason of the setting of the outlet valve 13 amounts to about twice the measuring pressure, the system being simultaneously pressure tested since the system has to be absolutely tight in order that a reliable measuring result shall be obtained. Moreover, the movement of the piston for a normal volume expansion of the oilis sensed so that, if said piston movement is not attained, a signal is given to indicate that the apparatus is faulty. A wrong mea suring. result can also be obtained if oil is not supplied because the supply line, a filter or the like is blocked, and the various operating phases are therefore super vised by a time relay which delivers a signal, should the various operating phases not have been carried out wit 'n normal intervals, course, the invention 15 not limited to the embodiment described above with reference to the accompanying drawing, but permits of modification within the scope of the appended claims. Thus the movable element of the expansion vessel 5 could be a diaphragm, bellows, enclosed air cushion or like means instead of a piston, and the actuating means of the movable element could be electrical or hydraulical instead of pneumatical. Besides, if desired, various filters 16 or centrifuges 17 can be connected in the system, and as indicated at 18 a control valve canbe connected between a point ahead of the inlet valve 12 and a point beyond the outlet valve 13. v
What I claim and desire to secure by Letters Patent 1. An apparatus for the discontinuous measurement of water impurities in oil by heating the oil in a con fined space to a temperature higher than the evaporation temperature of water comprising:
a container having a chamber with inlet and outlet means, said container having heat and temperature control means; at least one expansion vessel connected with said chamber, said expansion vessel being a cylinder and piston unit with the piston of said unit being adapted to be actuated by the volume increase of the oil which is responsive to the elevated temperature, and said cylinder having means for emptying the oil; said chamber and said expansion vessel forming a closed system through said inlet and outlet means, and said closed system having means for regulating and measuring the pressure produced by the heating of the oil, whereby the oil is degasified by reducing the volume in the expansion vessel and the heating of the oil in said chamber so thatsaid measurement can be made.
2. The apparatus of claim 1 including a buffer means for the heated oil between said chamber and said expansion vessel.
3. The apparatus of claim 1 including a dome at the top of said chamber for gases leaving said oil and said outlet means extending from said dome.
4. The apparatus of claim 1 including expansion vessels of various volumes adapted for connection with said chamber.