SYSTEM AND METHOD FOR REMOVAL OF WATER FROM OIL

Abstract

The present invention relates to a system for removing water from oil from an oil supply, where the system comprises a housing comprising an inner opening, an oil inlet tube connecting the oil supply and an oil inlet of the housing, where the oil inlet tube comprises an inlet pump adapted to provide a flow of oil in a direction from said oil supply to said oil inlet, an oil outlet tube connecting an oil outlet of the housing and the oil supply, where the oil outlet tube comprises an outlet pump adapted to provide a flow of oil in a direction from said oil outlet to said oil supply, an air inlet tube providing a gas connection between an air supply unit and an air inlet of the housing, and an air outlet tube providing a gas connection between an air outlet of the housing and the air supply unit, where said outlet pump is adapted as to provide a flow at a higher pumping flow rate than the pumping flow rate provided by said inlet pump. The invention further relates to a method of removing water from oil from an oil supply.

Claims

1. A system operable to remove water from oil of an oil supply, wherein the system comprises: a housing defining an inner space; an oil inlet tube fluidly connecting an oil supply to an oil inlet of the housing; an inlet pump fluidly coupled to the oil inlet tube, wherein the inlet pump is configured to pump a first flow of oil from the oil supply to the oil inlet according to a first pumping flow rate; an oil outlet tube fluidly connecting an oil outlet of the housing to the oil supply; an outlet pump fluidly coupled to the oil outlet tube, wherein the outlet pump is configured to pump a second flow of oil from the oil outlet to the oil supply according to a second pumping flow rate; a gas inlet tube fluidly connecting a gas supply unit to a gas inlet of the housing; and a gas outlet tube fluidly connecting a gas outlet of the housing to the gas supply unit, wherein the second pumping flow rate is greater than the first pumping flow rate, wherein the oil outlet is positioned at a vertically higher location than the oil inlet.

2. The system of claim 1, wherein a first part of the inner space of the housing is positioned downstream of the oil inlet and upstream of the oil outlet.

3. The system of claim 1, further comprising a heating element positioned upstream of the oil outlet.

4. The system of claim 1, wherein the gas inlet of the housing is positioned downstream of the oil inlet.

5. The system of claim 2, further comprising a porous material positioned in the first part of the inner space.

6. The system of claim 5, wherein the porous material is positioned at least partly downstream of the gas inlet.

7. The system of claim 2, wherein the gas outlet is positioned within a second part of the inner space of the housing, the second part being positioned vertically above the oil outlet.

8. The system of claim 1, further comprising an oil filter positioned in the oil outlet tube.

9. The system of claim 8, wherein the oil filter is positioned downstream of the outlet pump.

10. The system of claim 8, further comprising a gas vent tube configured to fluidly connect the oil filter to the inner space of the housing.

11. A method of removing water from oil of an oil supply, wherein the method comprises: providing a housing that defines an inner space, wherein the housing comprises an oil inlet and an oil outlet positioned at an oil outlet position that is vertically higher than the oil inlet; enabling oil to flow from an oil supply through an oil inlet tube to the oil inlet of the housing, fluidly coupling an inlet pump to the oil inlet tube so as to provide a first flow of oil from the oil supply to the oil inlet according to a first pumping flow rate, after a surface level of the oil rises at least to the oil outlet position, releasing to the oil outlet, the oil and any foam formed on a surface of the oil so that the released oil and foam flows to an oil outlet tube that is fluidly connected to the oil supply, fluidly coupling an outlet pump to the oil outlet lube so as to provide a second flow of oil from the oil outlet to the oil supply according to a second pumping flow rate, introducing a flow of a gas from a gas supply unit, through a gas inlet tube and into the inner space of the housing; and removing a flow of the gas from the inner space of the housing through a gas outlet tube, wherein pumping flow rate is greater than the first pumping flow rate.

12. The system of claim 1, wherein: a portion of the oil, when entering the oil inlet, comprises a percentage of water; the portion of the oil, when exiting the oil outlet, comprises a decreased percentage of water; the gas supply unit is operable to supply a gas; and the decreased percentage is caused, at least in part, by an interaction of the gas with the oil.

13. The method of claim 11, wherein: a portion of the oil, when entering the oil inlet, comprises a percentage of water; the portion of the oil, when exiting the oil outlet, comprises a decreased percentage of water; the gas supply unit is operable to supply a gas; and the decreased percentage is caused, at least in part, by an interaction of the gas with the oil.

Description

[0070] The structure and function of the system and the method of using it will be described in more detail below with references to exemplary embodiments shown in the drawings wherein,

[0071] FIG. 1 shows an embodiment of a system according to the invention.

[0072] FIG. 2 shows an embodiment of a system according to the invention.

[0073] In FIG. 1, a system 1 for removing water from oil from an oil supply (not shown) is shown.

[0074] The system 1 is shown to have an oil inlet tube 2 and an oil outlet tube 3.

[0075] The oil inlet tube 2 connects the oil supply at a first end 2a and an oil inlet 4 of a housing 5 at a second end 2b. The oil inlet tube 2 is led through an inlet pump 6 which is adapted to provide a flow of oil in a direction from said oil supply to said oil inlet 4 as indicated by the arrow 2′.

[0076] It is shown that the oil inlet tube 2 may further be led through a non-return valve 7 for preventing oil returning to the oil supply via the oil inlet tube 2 (i.e. counter to the direction of the arrow 2′). The non-return valve 7 may be set at e.g. 4 bars to prevent oil from the oil supply from entering the system at standstill. The non-return valve 7 may be arranged downstream of the inlet pump 6.

[0077] The oil inlet tube 2 may further be led through a heating element 8 for heating the oil before it enters the housing 5 (e.g. to 50° C.-80° C.). However, it is foreseen that the heating element 8 may be arranged in the housing 5 instead, as long as it heats the oil before the oil is treated in the housing 5. The heating element 8 may e.g. provide 1000 Wand include a temperature control to ensure that the oil is heated correctly according to the specific temperature of the oil so that the required oil temperature of the oil in the housing 5 is reached. The heating element 8 may be arranged downstream of the inlet pump 6 and/or of the non-return valve 7.

[0078] At a first end 10, the oil outlet tube 3 connects an oil outlet 9 of the housing 5 to said oil supply at a second end 11. The oil outlet tube 3 is led through an outlet pump 12 which is adapted to provide a flow of oil in a direction from said oil outlet 9 to said oil supply as indicated by the arrow 3′.

[0079] Said outlet pump 12 is adapted to provide a flow at a higher pumping flow rate than the pumping flow rate provided by said inlet pump 6. In one embodiment, the pumping flow rate of the outlet pump 12 may be more than 10% higher than the pumping flow rate of the inlet pump 6. In one embodiment, the pumping flow rate of the outlet pump 12 may be more than 50% higher than the pumping flow rate of the inlet pump 6.

[0080] The oil outlet tube 3 may further be led through an oil filter 13 and a second non-return valve 14, both of which may be arranged downstream of the outlet pump 12.

[0081] In a preferred embodiment of the invention, the oil inlet 4 of the housing 5 is placed at a vertically lower position than the oil outlet 9 of the housing 5. By vertically lower is to be understood in relation to gravity, when the system is configured, as it would be during operation. Hence, an item released at the plane of the vertically, i.e. gravitationally higher, oil outlet 9 and subjected to no other forces than gravity would fall towards the plane in a vertically lower position such as the plane in which the oil inlet 4 is placed. In other dimensions than the vertical direction, the oil inlet 4 and the oil outlet 9 of the housing 5 may be placed independently of each other, such that they may be on the same side of the housing 5, on opposing sides, or at an angle compared to each other.

[0082] In a variant of the invention, the oil inlet 4 of the housing 5 is placed in the lower half of the chamber 5. In such an embodiment, the oil outlet 9 of the housing 5 may be placed in the upper half of the chamber 5. Upper and lower is still considered relative to the direction of gravity, when the chamber 5 is in the position it will be in during operation of the system for removing water from oil.

[0083] Placement of the oil inlet 4 of the housing 5 above the oil outlet 9 of the housing 5 enables the system to operate as an overflow system, wherein the fluid exits the chamber 5 once a certain level has been reached. The dimensions of the chamber 5 as well as the vertical position of the oil outlet 9 of the chamber 5 may vary between different embodiments of the system such that the volume of fluid, which may be contained within the chamber, before the oil outlet is reached by the surface level of the fluid, is matched to the specific embodiment of the system.

[0084] The oil filter 13 may be arranged in a filter unit (not shown) and may comprise (be made of) a natural or synthetic polymer, such as a cellulose material. The oil filter 13 may have a cylindrical shape with an inner opening, where an outer surface of the oil filter 13 defines an inlet of the oil filter 13, so that the oil flows from the outer surface to the inner opening of said oil filter 13 before leaving the oil filter 13 (and the filter unit).

[0085] The second non-return valve 14 may be a back pressure valve 14, so that a pressure is applied on the oil filter 13.

[0086] As explained earlier, it is known when having e.g. air present in the oil that the pressure drop across the oil filter 13 will cause air bubbles in the oil to expand into a larger volume and may also release dissolved air into the oil. This expansion of air will pull solid particles to be filtered through the pores or openings of the oil filter 13 and release already trapped solid contaminants, thereby leading to a decreased filtering efficiency.

[0087] Pressurising the filtered oil at the outlet of the oil filter 13, i.e. a back pressure by use of the second non-return valve 14, ensures that all air in the oil flowing through the oil filter 13 remains dissolved in the oil. Thus, no free air bubbles are formed when the oil passes through the oil filter 13. For this reason, a back pressure may be arranged at the outlet side of the oil filter 13.

[0088] An air vent tube 15 is shown to connect the oil filter 13 with the housing 5. However, it is foreseen that said air vent tube 15 connects a filter unit (containing the oil filter 13 in an inner opening) with the housing 5.

[0089] When providing that the outlet pump 12 operates at a higher pumping flow rate than the inlet pump 6, not only oil, but also an amount of air, is led to the oil filter 13 and filter unit.

[0090] As mentioned earlier, it is desired to have a minimum amount of air present in the oil, when it flows through the oil filter 13. For this reason, it is an advantage that the system 1 comprises the air vent tube 15 in order to remove as much air as possible from the oil+air mixture being pumped out from said housing 5 and in order to lead the air back to said housing 5 as shown by the arrow 15′.

[0091] Advantageously, the air vent tube 15 is connected to a vertically upper part of the said filter unit (oil filter), as air would usually accumulate at said vertically upper part.

[0092] A third non-return valve 16 may be arranged in the air vent tube 15 to allow air to leave, but not enter, the oil filter 13 (filter unit).

[0093] In FIG. 1, it is shown that the system 1 further comprises an air inlet tube 17, an air outlet tube 18 and an air supply unit 19.

[0094] The air inlet tube 17 provides a gas connection between the air supply unit 19 and an air inlet 20 of the housing 5. An air pump 21 (fan/air vent) may be inserted in the air inlet tube 17 to provide a flow of air in a direction from said air supply unit 19 to said housing 5, as is indicated by the arrow 17′, to ensure that the required flow of air is introduced into the housing 5.

[0095] The air outlet tube 18 provides a gas connection between an air outlet 22 of the housing 5 and the air supply unit 19. Air containing an increased amount of water (maybe even saturated air) compared to the air introduced in said housing 5 may then leave said housing 5 and flow to said air supply unit 19 as is indicated by the arrow 18′.

[0096] The air supply unit 19 may comprise a condensing system 23 for removing at least part of the water content in the air. The condensing system 23 may be a fan-cooled radiator, a cooling liquid condensing system or other. The water removed from the air may leave the system via a water drain tube 24.

[0097] FIG. 2 shows an embodiment of a system 1 according to the invention.

[0098] For similar features as the features shown in FIG. 1, similar reference numbers have been used.

[0099] As in FIG. 1, the system 1 shown in FIG. 2 comprises an oil inlet tube 2, an oil outlet tube 3, an air inlet tube 17 and an air outlet tube 18. However, in FIG. 2, the oil inlet 2 and oil outlet tubes 3 are shown to be connected to an oil supply 25.

[0100] In FIG. 2, the housing 5 of the system 1 is shown to have an L-shape comprising a lower surface 26, a middle surface 27 and a top horizontal surface 28, and a first 29, second 30 and third vertical surface 31.

[0101] In an inner opening 32 of the housing 5, a heating element 8 and a porous material 33 may be arranged.

[0102] As is indicated by the arrows, the oil is introduced into the housing 5 via the oil inlet 4 (lower horizontal surface 26) and is filling up the inner opening 32 of the housing 5 and passes the porous material 33, until the oil surface 36 reaches the oil outlet 9 (third vertical surface 31). The filled part of said inner opening 32 defines a first part 34 of said inner opening 32 arranged downstream of said oil inlet 4 and upstream of said oil outlet 9. The remainder of said inner opening 32 defines a second part 35 of the inner opening 32 of said housing 5, said second part 35 being arranged vertically above said oil outlet 9. On the way from said oil inlet 4 to said oil outlet 9, the oil is heated by the heating element 8.

[0103] Simultaneously, as indicated by the arrows, air is introduced into the housing 5 via the air inlet 20 arranged in said first part 34 downstream of said oil inlet 4 and upstream of said oil outlet 9 (middle horizontal surface 27). The air mixes with the oil and is divided into several small air bubbles when passing the porous material 33. During the mixing, the air is heated by the heated oil and absorbs water from the oil before leaving the housing 5 via the air outlet 22 arranged at the second part 35 of said inner opening 32, said second part 35 being arranged vertically above said oil outlet 9 (top horizontal surface 28).