Title:
TANK-WASHING APPARATUS
United States Patent 3565342


Abstract:
Apparatus concerned generally with tank-washing apparatus and is specifically concerned with an apparatus wherein the possibility of a static spark being generated is greatly minimized. An electrical conductor is positioned from the end of the inwardly protruding conduit-nozzle which is above the surface of the liquid, which conductor extends into the liquid.



Inventors:
James, Orem W. (Red Bank, NJ)
Leonard, Lione V. (Mountainside, NJ)
Application Number:
04/863746
Publication Date:
02/23/1971
Filing Date:
09/24/1969
Assignee:
BUTTERWORTH SYSTEM INC.
Primary Class:
Other Classes:
239/71, 239/302
International Classes:
B05B3/02; B05B3/14; B08B9/093; (IPC1-7): B05B3/00
Field of Search:
239/227,71,72,1,302
View Patent Images:



Primary Examiner:
Lloyd, King L.
Attorney, Agent or Firm:
Manahan, And Wright Heilman W. O.
Claims:
1. A tank-washing assembly adapted to be used in a tank containing combustible fluid which is adapted to minimize the possibility of a static discharge occurring between said tank-washing assembly and said combustible fluid which comprises in combination: (1) a tank containing in the bottom thereof; (2) a combustible fluid; (3) a nozzle-washing mechanism having integral therewith; (4) a nozzle, which nozzle-washing mechanism is adapted to be disposed within said tank above said combustible fluid, said nozzle-washing mechanism comprising; (5) a rotatable housing which is adapted to rotate about; (6) a nonrotatable bearing sleeve; (7) an electrical conductor extending from said nozzle-washing mechanism into said fluid and to the bottom of said tank, said electrical conductor then extending from the bottom of said tank to the top of said tank, and (8) warning means which is activated upon the breakage of said electrical conductor.

2. Apparatus as defined by claim 1 wherein said rotatable housing of said nozzle-washing mechanism is adapted to be rotated about the longitudinal vertical axis of said mechanism on said nonrotatable bearing sleeve; and wherein said nozzle is adapted to be oscillated about a horizontal axis and which also comprises in combination; (9) compensating means which will prevent the twisting of said electrical conductor when said nozzle-washing assembly is rotated about said vertical axis comprising; (10) a first gear attached to said nonrotatable bearing sleeve of said nozzle-washing mechanism; (11) a second gear suitably attached to said rotatable housing and which is adapted to be rotated about said vertical axis, said second gear being attached to the one end of said conductor, said first and said second gears being interconnected by, (12) a third idler gear in a manner that, as said assembly rotates about said longitudinal axis in one direction, said gear will rotate about its own axis in the opposite direction thereby preventing twisting of said electrical conductor.

3. Apparatus as defined by claim 1 wherein said rotatable housing of said nozzle-washing mechanism is adapted to be rotated about the longitudinal vertical axis of said mechanism on said nonrotatable bearing sleeve; and wherein said nozzle is adapted to be oscillated about a horizontal axis and which also comprises in combination; (9) compensating means which will prevent the twisting of said electrical conductor when said nozzle-washing assembly is rotated about said vertical axis.

4. Apparatus as defined by claim 3 wherein said compensating assembly comprises; (10) a first gear attached to said nonrotatable bearing sleeve of said nozzle-washing mechanism (11) a second gear suitably attached to said rotatable housing and which is adapted to be rotated about said vertical axis, said second gear being attached to the one end of said conductor, said first and said second gears being interconnected by, (12) a third idler gear in a manner that, as said assembly rotates about said longitudinal axis in one direction, said second gear will rotate about its own axis in the opposite direction thereby preventing twisting of said electrical conductor.

5. A tank assembly adapted to minimize static discharge which comprises in combination: (1) a tank; (2) a combustible fluid contained in said tank; (3) an electrically conductive fluid conduit protruding into said tank which terminates in; (4) a nozzle positioned above the surface of said fluid, and; (5) an electrical wire conductor extending from said fluid conduit into said fluid and attached to the bottom of said tank, whereby the potential gradient between said nozzle and the surface of said fluid is minimized.

6. Assembly as defined by claim 5 wherein said nozzle comprises a nozzle-washing mechanism, wherein said electrical wire conductor is positioned substantially directly below said nozzle-washing mechanism and wherein said combustible fluid comprises hydrocarbons.

7. A tank-washing assembly adapted to be positioned in a tank containing combustible fluid which is adapted to minimize the possibility of a static discharge occurring between said tank-washing assembly and said combustible fluid which comprises in combination: (1) an electrically conductive fluid conduit which terminates in; (2) a nozzle-washing mechanism having integral therewith; (3) a nozzle positioned above the surface of the combustible fluid, said nozzle-washing mechanism comprising; (4) a rotatable housing which is adapted to rotate about; (5) a nonrotatable bearing sleeve and; (6) an electrical wire conductor extending from said nozzle-washing mechanism into said fluid and attached to the bottom of said tank.

8. Assembly as defined by claim 7 wherein said electrical wire conductor is disposed substantially directly below said nozzle-washing mechanism.

9. Assembly as defined by claim 7 wherein said nozzle attached to said tank-washing assembly has integral therewith; (7) an expanded electrical conductive element at the bottom thereof above the surface of said fluid, whereby sharp edges and sharp points are avoided.

10. A tank assembly adapted to minimize static discharge which comprises in combination: (1) a tank; (2) a combustible fluid contained in said tank; (3) an electrically conductive fluid conduit terminating in a nozzle; (4) protruding into said tank and supported solely from the top of said tank; said nozzle positioned above the surface of said fluid, and; (5) an electrical conductor extending from said fluid conduit into said fluid, whereby the potential gradient between said nozzle and the surface of said fluid is minimized.

11. Assembly as defined by claim 10 wherein said nozzle comprises a nozzle-washing mechanism, wherein said electrical conductor is positioned substantially directly below said nozzle washing mechanism and wherein said combustible fluid comprises hydrocarbons.

12. A tank-washing assembly adapted to be positioned in a tank containing combustible fluid which is adapted to minimize the possibility of a static discharge occurring between said tank-washing assembly and said combustible fluid which comprises in combination: (1) an electrically conductive fluid conduit which terminates in; (2) a nozzle-washing mechanism having integral therewith (3) a nozzle positioned above the surface of the combustible fluid, said nozzle washing mechanism comprising; (4) a rotatable housing which is adapted to rotate about; (5) a nonrotatable bearing sleeve and; (6) an electrical wire conductor extending from said nozzle-washing mechanism into said fluid.

13. Assembly as defined by claim 12 wherein said electrical wire conductor is disposed substantially directly below said nozzle-washing mechanism.

14. Assembly as defined by claim 12 wherein said nozzle attached to said tank-washing assembly has integral therewith; (7) an expanded electrical conductive element at the bottom thereof above the surface of said fluid, whereby sharp edges and sharp points are avoided.

Description:
The present invention is concerned with a unique apparatus which is particularly adapted for cleaning the interior wall surfaces of a container vessel. The present application is a continuation-in-part of U.S. Ser. No. 709,292 filed Feb. 29, 1968 entitled "Tank Washing Apparatus," Inventors James W. Orem and Leonard V. Lione, now abandoned.

The invention is especially concerned with a tank-washing apparatus utilizing high-pressure jetstreams of a cleaning or washing liquid and impinging said jetstream against the interior surfaces of the container vessel. The invention is more particularly concerned with a tank-washing apparatus wherein the jetstreams are directionally controlled and directed so as to effectively clean predetermined areas within the container vessel. The invention, in essence, comprises an improvement over the apparatus described in U.S. Pat. 2,917,243 patented Dec. 15, 1959 entitled, "Tank Washing Apparatus," inventor Leonard V. Lione. The invention also comprises an improvement over the apparatus described in copending application U.S. Ser. No. 561,088 filed Jun. 28, 1966, now U.S. Pat. No. 3,379,379 entitled, "Tank Washing Apparatus having Oscillating Nozzles," inventor James W. Orem, and also constitutes an improvement over Ser. No. 699,163 entitled, "Tank Washing Apparatus" filed Jan. 19, 1968, now Pat. No. 3,472,451 for James W. Orem, Leonard V. Lione and Daniel T. Turco. The invention specifically is concerned with an improvement of these described apparatuses whereby the possibility of a static spark being generated is very greatly minimized.

Heretofore in the art, the conventional method of washing sedimentation and the like from tanks, such as ship tanks, was to empty the tank of combustible materials and then to insert the tank-washing unit within the tank. However, a more recent technique has been to permanently install the washing element or assembly within the tank and then program the washing cycle of the washing assembly by means of a detachable programming assembly positioned on top of the washing assembly without the tank. Thus, at all times the actual tank-washing assembly would be positioned within the tank irrespective of whether the tank contains material or not, and irrespective of the degree to which the tank is full of combustible material. The washing assembly is supported from the roof of the tank and does not extend to the bottom of the tank.

It is also known that with respect to combustible fluids, particularly hydrocarbon fluids, being agitated with the tank, static charges build up in the oil particularly on the surface of the oil hydrocarbons, which static charges are constantly being dissipated by local discharge. However, where there is a lack of good conductivity of the oil, such static charges are not readily dissipated. It is also known that if a protrusion is positioned with in the tank, such as a tank-washing assembly, and a vapor gap exists between the lower end of the assembly and the upper surface of the hydrocarbons, a higher voltage gradient may occur in the gap directly below the end of the protrusion such as the washing assembly.

Thus the present invention is concerned with a method for washing apparatus assembly wherein the possibility of static spark discharge is substantially completely eliminated. The present invention positions an electrical conductor substantially directly below the end of the protrusion which electrical conductor extends from the protrusion down to the oil surface, and thence preferably down to the bottom of the vessel. This electrical conductor will lower the potential gradient below the end of the protrusion or washing assembly thereby minimizing the possibility of a static spark passing between the upper surface of the oil to the lower end of the assembly, through perhaps an explosive mixture.

The present apparatus may be more fully understood by reference to the drawings illustrating embodiments of the same. FIG. 1 is a front view of an apparatus positioned within a tank above the surface of a combustible fuel within the tank. FIG. 2 is a side view showing in some detail the method of rotating the nozzle about a vertical axis and, at the same time, oscillating the nozzle about a horizontal axis without continually twisting the electrical conductor passing from the washing assembly to the tank bottom. FIG. 3 is a top view showing in detail the compensating gear box arrangement by which this is secured. FIG. 4 shows in some detail a safety device by which any breakage of the conductor may be readily detected, while FIGS. 5 and 6 illustrate other embodiments of the invention.

Referring specifically to FIG. 4 a washing assembly 1 is shown partially protruding within a tank 2 which contains a combustible fluid 3. This washing assembly is supported from the roof of the tank and does not extend to the tank bottom. As described in the before-identified applications, programming of washing assembly 1 is actuated by means of detachable programming assembly 4 positioned without the tank. In essence, the programming assembly 4 rotates washing nozzle 5 about a vertical longitudinal axis and oscillates nozzle 5 about a horizontal axis in a manner to secure any predetermined desired washing pattern. Washing fluid is introduced by means of conduit 6. Washing assembly 1 comprises an upper stationary housing 7 and a lower rotating housing 8, which rotates about journal 9, The bearing for rotating housing 8 is a sleeve 20 (See FIG. 2) which is affixed to the lower end of stationary housing 7.

Electrical conductor 10 extends from washing assembly 1 to the bottom of tank 2 and thence preferably to the top of tank 2 to safety alarm mechanism 11. It is evident that if no means were taken to compensate the action when rotating housing 8, electrical conductor 10 would be twisted one revolution each time rotating housing 8 is rotated. In order to compensate for this undesirable twisting of the electrical conductor 10, compensating means 12, which will be hereafter more specifically described, is attached to the outer surface of rotating housing 8 and to sleeve 20. Thus, it is evident that the chance of sparking occurring between the top surface of combustible fluid 3 and the lower end of nozzle 5 is minimized due to the fact that the potential gradient is lowered by the presence of the electrical conductor 10 which is electrically bonded to the tank.

Referring specifically to FIG. 2, similar parts with respect to FIG. 1 are similarly numbered. Nozzle 5 is positioned above the surface level of combustible fluid 3 creating a vaporous gap, the magnitude of which will vary and will be a function of the height of the fluid within the tank. Electrical conductor 10 which is electrically connected to the tank is shown extending into the fluid adjacent to nozzle 5 in order to lower the potential gradient in the vicinity of nozzle 5. Compensation means 12 which avoids the twisting of conductor 10 comprises a plurality of interacting gearwheels 13, 14 and 15. (See FIG. 3.) Rotating housing 8 rotates about an internal stationary sleeve bearing 20 which is integral with nonrotating housing 7. A first gear 14 is affixed to stationary sleeve 10 and does not rotate. However, as housing 8 rotates, a second gear 13 of compensating means 12 is suitably affixed to housing 8 and thus will revolve about the vertical longitudinal axis of housing 8. Gear 13 having the same number of teeth as gear 14 is interconnected with stationary gear 14 by means of a third or idler gear 15. Thus, as housing 8 makes one complete rotation as, for example, clockwise, gears 13 and 15 being attached to rotating housing 8, will revolve about the vertical or longitudinal axis of housing 8. However, rotating gear 13 having attached thereto extension 19 and conductor 10 will rotate about its own axis counterclockwise, thereby preventing any twisting of conductor 10.

Referring specifically to FIG. 4, safety mechanism 11 comprises a spring 16 maintained in compression by electrical conductor 10. Thus, if conductor 10 is broken the spring will actuate a hammer 17 which, in turn, will move upwardly and actuate a conventional alarm system 18 as, for example, an alarm horn system.

Referring specifically to FIGS. 5 and 6, similar parts are similarly numbered with respect to the foregoing figures. In FIG. 5, nozzle 5 has attached to its lower end thereof a circumferential balloon element 30 of an electrically conductive material which is designed to provide a smooth surface area 31 immediately above the fluid 3 and eliminate any sharp edges and pointlike surfaces of the nozzle which would tend to increase the potential gradient. FIG. 6 illustrates an adaptation wherein the surface of the conductor 10 where it is adjacent to nozzle 5 is greatly extended by the utilization of a spherelike element 40. This provides a means to minimize the potential gradient between nozzle 5 and the liquid surface in cases where it is not possible to position conductor 10 close to nozzle 5. The diameters of the conductor, the balloon, and the sphere may vary appreciably and be a function of many factors some of which are size and configuration of tank, fuel being stored, mechanical strengths desired, and the like. For example, the diameter of the conductor may vary from about 1/8" to 1", preferably 1/4" to 1/2" as, for example, 3/8". The outside diameter of the balloon element 30 may vary from about 2" to 6" to 2', such as about 10". The shape and surface of the balloon element are such that there are no sharp edges, small radii of curvature and pointlike projections. Such a shape and surface, for example, may be generated by revolving about the axis of the nozzle a smooth curve formed by extending an element of the nozzle bore and curbing it back to meet the outside of the nozzle at a distance before the end of the nozzle. The minimum radius of curvature of such generating curve generally should be 1", preferably greater, say 2", in the region first approached by the liquid surface, although within a depression in the bottom of the balloon element near the end of the nozzle bore the minimum radius of curvature may be less than 1". One specific embodiment of the balloon element is shown in FIGS. 5 and 6; however, it is obvious that many modifications and other configurations may be made within the scope of the invention. The diameter of the spherelike element 40 is such that a part of its surface is in close proximity to the end of the nozzle in its downward position. The shape of the spherelike element 40 need not be a true sphere but may be any suitable size and shape having a smooth surface without sharp edges and pointlike protrusions and preferably with the surface having a minimum radius of curvature of about 1".

It is to be understood that the foregoing relates to a tank-washing nozzle made of an electrically conductive material that is electrically connected to the tank which also is constructed of a conductive substance.