US2626054A - Oil tank water drainer - Google Patents

Description

Jan. 20, 1953 F. HENIGMAN OIL TANK WATER DRAINER Filed Sept. 29, 1950 Inventor AIM/may Patented Jan. 20, 1953 UNITED STATES PATENT OFFICE OIL TANK WATER DRAINER Frank Henigman, Chicago, Ill.

Application September 29, 1950, Serial No. 187,641

3 Claims.

This invention relates to a water drainer attachment for oil tanks such as stock tanks or oil storage tanks of the type used in crude oil production fields and has for its primary object to provide a drainage tank of extremely simple construction which may be quickly and easily attached to a storage tank for oil and arranged so that any water contained in the oil will be separated therefrom and fiow by gravity into the drainage tank from which the water can be removed without loss of any of the oil from the storage tank.

Another object of the invention is to provide a drainage tank having means for visually indicating the amount of water therein and for additionally indicating whether or not all of the water has been drained from the storage tank which is connected to the drainage tank.

A further object of the invention is to provide a drainage tank from which water is adapted to be drained from adjacent the bottom thereof through the top of the drainage tank by the pressure of the oil in the storage tank with the drainage of the water from the drainage tank being under the control of an operator having available a visual indication at all times of the water level in the drainage tank to prevent draining off any of the oil while accomplishing the draining off of water.

Still'a further object of the invention is to provide a drainage device for storage tanks which will prevent the accumulation of water in the bottom of a storage tank and the resulting damage to the storage tank bottom and which will additionally function efiectively to prevent a loss 'of oil in connection with the draining off of water from a storage or stock tank.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawing, illustrating presently preferred embodiments thereof, and wherein:

' be of any conventional construction usually ineluding an outlet nipple 6 in a side wall thereof and adjacent its bottom which is normally closed I by a cap I, which is threaded to the outer end thereof. The. top of the tank is ordinarily provided with a filling port 8, normally closed by a plug 9, when not in use, and may be provided with a conventional air vent iii for venting the tank while oil is being drained therefrom and for facilitating the venting of the tank for draining off water from the bottom thereof, as will hereinafter become apparent. The tank bottom I I is provided with an internally threaded port I2 and the side wall thereof, adjacent the bottom H and near the port [2 is provided with a similar internally threaded port IS. The ports 12 and I3 constitute conventional parts of the tank 5 and are employed in the draining off of water from the bottom part of the tank. The parts 6 to l3, inclusive of the tank 5, as illustrated in Figure 1 and as briefly described are all of conventional construction and form no part of the present invention.

The water drainer unit, designated generally l4 and comprising the invention includes a relatively small tank l5 which is adapted to be dis posed preferably with the top thereof slightly beneath the level of the tank bottom ll, so that if the tank bottom H is resting on the ground the drainage tank It will ordinarily be disposed in a pit l6 and thus slightly below the ground level, as illustrated in Figure 1. The top I! of the tank l5 may be welded to the side wall of the tank and thus permanently secured thereto or said tank top ll may be detachably secured to the side wall of the tank by detachable fastenings, not illustrated in Figure l. I? is provided with an external nipple l8 through which a vertical portion I9 of a drain pipe 20 extends. The lower end of the drain pipe portion l9 opens adjacent the bottom of the drain tank l5, as seen in Figure 1, and the drain pipe 2!], above the top of the tank l5 has a horizontally disposed portion extending away from the tank IS the opposite end of which, not shown, is adapted to open at any suitable drainage point. Said horizontal portion of the drain pipe 26 is provided with a manually controlled shutofi valve 2|.

A conduit 22 has one end threadedly engaging in the boss l2 and in communication with the interior of the bottom portion of the tank 5 and the opposite end of said conduit 22, which is disposed at an angle tothe first mentioned end, is connected to a boss 23 of the drain tank [5 and opens into said drain tank between the top and bottom thereof but preferably nearer to the top I! than to the bottom of the tank 15. The conduit 22 includes an elbow joint 24 by which its angularly disposed end portions are connected.

The top wall A conduit, designated generally 25, includes a pipe 26 which is preferably transparent and which has one end threadedly engaging the boss I3 and opening into the tank 5 above and adjacent the tank bottom H. Conduit 25 includes a pipe 21 which is disposed at an angle to the pipe 26 and has one end connected to a boss 28, formed in the top wall I! of the tank I5 and which opens into the top of the drainage tank I5. The opposite, adjacent ends of the pipes 26 and 21 are connected by an elbow coupling 29.

A pair of elbow couplings 30 are tapped into the side wall of the drainage tank I5, one adjacent the top and the other adjacent the bottom thereof and in vertical alignment. A sight tube 3| of a transparent material is interposed between and connected at its ends to the couplings 30 and through said couplings is in communication with the drainage tank I5 adjacent its top and bottom.

'The drainage tank I5 is provided in its side wall and adjacent its bottom 32 with a port 33, formed by an externally disposed internally threaded boss and said port 33 is normally closed by a threaded plug 34.

Figure 2 illustrates a slightly modified form of the drainage tank, designated generally I5a and which difiers from the drainage tank I5 only in that its top wall I'Ia may be formed integral with the side wall of the tank |5a and is provided with an integral relatively large upstanding neck 35 having an annular external flange 35 at its upper end. A cover plate 31 is disposed over and closes the upper end of the neck 35 and is detachably secured thereto by nut and bolt or other suitable fastenings 38 so that the cover plate 31 may be removed for cleaning the interior of the drainage tank.

From the foregoing it will be readily apparent that any water contained in the oil 39 which fills or partially fills the storage tank 5 will settle to the bottom of said tank and will thus find its way to the drain conduit 22 through which it will flow by gravity into the drain tank I5. Unless there is suificient water to fill the drain tank I5, it will be readily apparent that some of the oil 39 will also flow by gravity into the drain tank I5, since it is below the level of the storage tank 5 so that the tank I5 will always be filled ordinarily, partly with water and partly oil. Due

to the greater specific gravity of the water, the

water will be disposed in the tank I5 below the oil 39 and in Figure l the water has been indicated at 40. It will be readily apparent that this water level will be visually indicated by the sight tube 3| in which the water level 40 will correspond to the water level in the drainage tank, oil filling the upper portion of the sight tube. As additional water settles to the bottom of the tank 5 and finds its way through the conduit 22 to the drain tank I5, the level of the water 40 will rise in the tank I5 causing a part of the oil 39 to be forced back from the tank I5 through the conduit 25 into the tank 5 until, eventually, if the water is not drained off of the tank i5 it will fill the conduit 25 and be visible in its transparent portion 26. However, ordinarily when the sight tube 3| indicates that the water level is relatively high in the drainage tank I5 the operator will open the valve 2| so that the pressure of the liquid in the tank 5 will force the water outwardly through the drain pipe 20. The operator by observing the fall of the water level in the tube 3| may shut the valve 2| before "the water level falls below the open lower end of the pipe portion I9 to prevent any of the oil above the water from entering the pipe portion I9 and be wasted by drainage. The upper conduit 25 allows the oil to return more rapidly to the tank 5 as water flows through the conduit 22 from the tank 5 to the drain tank I5 thus enabling the water level in the drain tank to be established more rapidly. However, the drain unit I4 will operate without the conduit 25 although less efficient since the water would then have to flow to the drain tank I5 through said conduit and the oil 39 would also have to escape back through the conduit 22 to the tank 5 to provide space for the additional water and this would prevent water accumulating in the tank I5 above the level of the conduit 22 whereas with both conduits being employed, the entire tank I5 can be filled with water. The transparent conduit portion 26 enables an experienced operator to accurately judge when the proper oil and water level has been obtained and how much water needs to be drained off from the tank I5, by observing the flow of liquid between the drain tank I5 and storage tank 5 through the conduit portion 256.

The dischar e port 33 may be employed in conjunction with conventional automatic drainage equipment, not illustrated, by connecting the port 33 to such equipment by a swing joint, not shown, so that the drain tank I5 may then operate automatically instead of by manual use of the valve 2|.

While the invention has been described for use with a storage tank for oil, it is to be un derstood that the drainage unit is equally well adapted for use for storage tanks containing other liquids having a specific gravity less than the specific gravity of water, such as gasoline. Obviously the storage tank and drain tank may be made in various sizes and shapes and it is not essential that the drainage tank be disposed entirely below the level of the storage tank so long as its bottom is sufiiciently below the level of the bottom of the storage tank so that the open lower end of the drainage tube portion I9 will likewise be disposed below the level of the storage tank bottom.

Various other modifications and changes are contemplated and may obviously be resorted to, without departing from the spirit or scope of the invention as hereinafter definedby the appended claims.

I claim as my invention:

1. The combination with a storage tank containing a liquid having a specific gravity less than the specific gravity of water, of a water drainage unit for use with the storage tank comprising a drainage tank having a top wall disposed below the level of the storage tank bottom, a first conduit having a lower end communitating with the drainage tank substantially above the drainage tank bottom and beneath the top of the drainage tank, said first conduit havin an upper end communicating with the storage tank adjacent its bottom, a second conduit having one end communicating with the top of the drainage tank and having an opposite end opening into the storage tank above the upper end of the first conduit, a drainage conduit having an inlet end disposed within the drainage tank and opening adjacent the drainage tank bottom and substantially below the level of the lower end of the first conduit, said drainage tank being closed except for said conduits, said drainage conduit extending outwardly from the drainage tank and being disposed with its uppermost portion adjacent the level of the bottom of the storage tank, and control means for shutting off the flow of liquid through the drainage conduit, the water contained in the storage tank draining therefrom by gravity through the first conduit to fill the bottom portion of the drainage tank and the remainder of the drainage tank will be filled with the other liquid of the storage tank to the capacity of the drainage tank, the other liquid of the storage tank being forced back from the drainage tank to the storage tank through said second conduit as the drainage tank fills with water, said control means being opened for draining off the water from the drainage tank.

2. A drainage unit as in claim 1, said second conduit having a transparent portion for visually indicating the flow of liquid therethrough and the type of liquid contained therein.

3. The combination with a storage tank containinga liquid having a specific gravity less than the specific gravity of water, of a water drainage unit for use with the storage tank comprising a drainage tank having a top wall disposed at a level not above the level of the storage tank bottom, a first conduit having a, lower end communicating with the drainage tank substantially above the drainage tank bottom and beneath the top of the drainage tank, said first conduit having an upper end communicating with the storage tank adjacent its bottom, a second conduit having one end communicating with the drainage tank above the lower end of said first conduit and having an opposite end opening into the storage tank above the upper end of the first conduit, a drainage conduit having an inlet end disposed within the drainage tank and opening adjacent the drainage tank bottom and substantially below the level of the lower end of the first conduit, said drainage conduit extending outwardly from the drainage tank above the level of the inlet end thereof, said drainage tank being closed except for said conduits, and control means for shutting off the flow of liquid through said drainage conduit, the water contained in the storage tank draining therefrom by gravity through the first conduit to fill the bottom portion of the drainage tank and the remainder of the drainage tank being filled with the other liquid of the storage tank to the capacity of the drainage tank, the other liquid of the storage tank being forced back from the drainage tank to the storage tank throughsaid second conduit as the drainage tank fills with water, said control means being opened for draining off the water from the drainage tank.

FRANK HENIGMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 374,879 Pearson Dec. 13, 1887 1,530,087 MacArthur Mar. 17, 1925 1,613,507 Feely Jan. 4, 1927 1,722,160 Smith July 23, 1929 FOREIGN PATENTS Number Country Date 174,548 Great Britain Feb. 2, 1922

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