WO2018130650A2

WO2018130650A2 - A device and method for cleaning interior surfaces of tanks and containers

Info

Publication number: WO2018130650A2
Application number: PCT/EP2018/050750
Authority: WO
Inventors: Ole MELDGAARD; Kim CHRISTOFFERSEN; Kim Pandrup CHRISTENSEN
Original assignee: Oreco A/S
Priority date: 2017-01-13
Filing date: 2018-01-12
Publication date: 2018-07-19
Also published as: WO2018130650A3

Abstract

The invention relates to a cleaning device (1) for cleaning interior surfaces of containers, such as oil-tanks (13). The cleaning device comprises a flushing liquid pipe (3) for the supply of liquid; an extended flushing liquid pipe (4), extending in a bend, such as 90 degrees, from the distal end of said flushing liquid pipe (3) and a down pipe (3a) extending from the distal end of said extending flushing liquid pipe (4). A cleaning head (7) is arranged at the distal end of said down pipe (3a), so as to form the connection between a nozzle hub (6) and said down pipe (3a). The nozzle hub (6) is rotatable around the longitudinal direction of cleaning head (7). A rotatable joint (5) is arranged between said down pipe (3a), and said cleaning head (7). The rotatable joint (5) is configured for being rotatable around a vertical axis (9). A nozzle hub (6) is arranged at the distal end of said cleaning head (7). The nozzle hub (6) is rotatable around an axis being perpendicular to said longitudinal direction of a vertical axis (9). One or more nozzles (8) are arranged on said cleaning head (7), configured for discharging jets of flushing liquids. A nozzle tip (11) is arranged at the distal end of said nozzle (8). The flushing liquid pipe (3) further comprises a plate (2) configured to fit the tank opening, arranged at a proximal end of said flushing liquid pipe (3) for mounting the cleaning device in a tank wall (14) of said oil tank (13) so as to extend into said oil tank (13).

Description

A DEVICE AND METHOD FOR CLEANING INTERIOR SURFACES OF TANKS AND CONTAINERS

FIELD OF THE INVENTION

The present invention relates to a cleaning device for cleaning interior surfaces of containers, such as oil-tanks.

BACKGROUND OF THE INVENTION

A tank cleaning machine is a machine used to clean e.g. cargo, process, underground storage containers and oils tanks. Oil tanks, in particular, must be cleaned on regular basis, primary to remove hazardous waste generated from tank bottoms, also referred to as sludge. Sludge is a common name for deposits of impurities found at the bottom of the oil tank, and represents a multitude of various pollution particles.

The invention relates to tank cleaning equipment, especially for oil tanks. Cleaning of an oil tank is typically done by means of a pipe lowered into the tank space, usually through the support Internal Floating Roof of the oil tank.

The tank-cleaning device typically comprises a liquid-pipe for supply of the flushing liquid to a flushing liquid pipe, which has at least one flushing nozzle for discharging the flushing liquid. A switch device is typically provided to bring the pipes and/or the nozzles to rotate around its axis. A control device is typically also provided to control the rotation of the liquid pipe and the flushing nozzle. Material settled on the tank wall and bottom and the cleaning medium are afterwards pumped out, to an external location to the tank.

A problem occurs with the lowering of the cleaning equipment, when the Internal Floating Roofs of the oil tank is made of easily distributive material and suffers from corrosion. In these situations, a top mounting of the cleaning device is not possible.

An improved tank cleaning device and method for protection of easily disruptive roof materials would be advantageous. OBJECT OF THE INVENTION

An object of the present invention is to provide an alternative to the prior art.

In particular, it may be seen as an object of the present invention to provide a device and method for cleaning interior surfaces of tanks and containers for protection of easily disruptive roof materials.

SUMMARY OF THE INVENTION

The invention relates, in a first aspect, to a cleaning device for cleaning interior surfaces of containers, such as oil-tanks, the cleaning device comprising a flushing liquid pipe for the supply of liquid; an extended flushing liquid pipe, extending in a bend, such as 90 degrees, from the distal end of the flushing liquid pipe and a down pipe extending from the distal end of the extending flushing liquid pipe; a cleaning head arranged at the distal end of the down pipe, so as to form the connection between a nozzle hub and the down pipe, the nozzle hub is rotatable around the longitudinal direction of cleaning head; a rotatable joint arranged between the down pipe and the cleaning head, the rotatable joint being configured for being rotatable around a vertical axis; a nozzle hub arranged at the distal end of the cleaning head, the nozzle hub is rotatable around an axis being perpendicular to the longitudinal direction of a vertical axis;

- one or more nozzles, arranged on the cleaning head, configured for discharging jets of flushing liquids; - a nozzle tip, being arranged at the distal end of the nozzle; wherein

- the flushing liquid pipe further comprising a plate configured to fit the tank opening, arranged at a proximal end of the flushing liquid pipe for mounting the cleaning device in a tank wall of the oil tank so as to extend into the oil tank.

The cleaning device may further comprise driving means to rotate the rotatable joint and the cleaning head of the cleaning device along the vertical axis.

The driving means may further comprise

a first rotational shaft extending from a location exterior to the plate and to the distal end of the flushing liquid pipe parallel to the flushing liquid pipe, - a second rotational shaft extending from the distal end of the flushing liquid pipe and to the rotational joint at which the second rotational shaft has a toothed connecting to the rotational joint so that rotation of the second rotational shaft results in a rotation of the cleaning head. The first rotational shaft and second rotational shaft are preferably rotationally joined, preferably by a bevel gear so that rotation of the first shaft result in a rotation of the second shaft and the cleaning head.

The driving means preferably comprises an actuator to rotate the first rotational shaft.

The cleaning device may further comprise a switch to bring the rotatable joint and the cleaning head to rotate along the vertical axis. Preferably, the nozzle hub is configured to rotate between two outer most positions, with a rotational speed being lower than 1 rpm, such as lower than 0.75 rpm, preferably lower than 0.5 rpm.

The nozzle tip is preferably replaceable arranged on the nozzle, so as to adapt for each specific tank design. The cleaning device may comprise a single nozzle on the nozzle hub.

The cleaning device may is preferably configured for use for internal floating roof tanks and to protection of easily disruptive roof materials.

A container, such as an oil tank, may comprise one or more cleaning devices according to the present invention, wherein the cleaning device preferably is side mounted on the oil tank.

In a second aspect, the present invention relates to a method of cleaning of interior surfaces. The method utilize a side mounting of a cleaning device in appatures on an oil tank to be cleaned, on the basis of a sequence programming with multiple steps on individual wash programs, controlling the movement of the cleaning device.

The nozzle rotating velocity is preferably 0.5 - 5 m/s, such as 0.5 - 2.5 m/s, preferably 0.5 - 1.0 m/s at a cleaning circle impact. The cleaning circle impact zone may have a diameter up to 10 meters, such as up to 20 meters, preferably up to 30 meter

The method may further comprise the step of variable speed function, so as to provide a repeating sweep at the same horizontal positioning with a nozzle rotating velocity of 0.1 - 5 rpm, such as 0.1 - 2.5 rpm, preferably 0.1 - 1.0 rpm at wall, and in tank area.

The method may further comprise a step function with Stop/Go function split between combinations lower than 30 sec. combination, such as lower than 20 sec. combination, preferably lower than 10 sec. combination.

Preferably, the method comprises the step of discrete intermediate cleaning section with rapid movement to next cleaning spot allowing differential speed at each rotation. The method may further comprise the step of Twin Nozzle Mode operation mode. The method may comprise two nozzles arranged separately on a nozzle hub. The Twin Nozzle Mode operation mode may be configured to secure a minimum interfering impact zones by alternating between nozzles directed into tank.

The method preferably utilizes one or more cleaning devices according to the present invention.

The method may utilize one or more cleaning devices according to the present invention, simultaneously operated. The cleaning device may comprise multiple nozzles configured to secure complete and minimum interfering sections of the entire tank.

The method may utilize one or more cleaning devices according to the present invention; the cleaning device may comprise variable washing liquid flow for multiple nozzles.

In the present context a number of terms are used in a manner being ordinary to the skilled person. Some of these terms are detailed below:

Internal Floating Roof is preferably meant to denote a roof top, floating on the liquid within the tank and rising and falling with the liquid level. One purpose of the internal floating roof is to minimize the gaseous zone above the stored liquid. Cleaning area is preferably meant to denote an area interior to the oil tank to be cleaned.

Nozzle jet is preferably meant to denote a stream of fluid discharged from a nozzle.

Nozzle rotating velocity is preferably meant to denote a velocity of the liquid jet when projected against the floor/wall of a container. The aspects of the present invention may each be combined with any of the other aspects. These and other aspects of the invention will be apparent from and el ucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE FIGURES

The present invention and in particular preferred embodiments thereof will now be disclosed in greater details with reference to the accompanying figures. The fig ures show ways of implementing the present invention and are not to be construed as being limiting to other possible embod iments falling within the scope of the attached claim set.

Figure 1 is a schematical ly view of a cleaning device according to the present invention. Figure 2 is a schematical ly view of a cleaning device according to the present invention, with driving means arranged .

DETAILED DESCRIPTION OF AN EMBODIMENT

Reference is made to fig ure 1 illustrating a cleaning device 1 for cleaning interior surfaces of containers, such as oil-tanks 13.

The cleaning device comprises a flushing liquid pipe 3 for the supply of liquid ; an extended flushing liq uid pipe 4, extend ing in a bend, such as 90 deg rees, from the distal end of the flushing liq uid pipe 3 and a down pipe 3a extend ing from the distal end of the extending flushing liquid pipe 4. A cleaning head 7 is arranged at the distal end of the down pipe 3a, so as to form a connection between a nozzle hub 6 and the down pipe 3a. The nozzle hub 6 is rotatable around the longitud inal direction of cleaning head 7.

A rotatable joint 5 is arranged between the down pipe 3a and the cleaning head 7 and is configured for being rotatable around a vertical axis 9 with a rotational speed of e.g . 0.01 - 10 rpm, such as 0. 1 - 10 rpm, preferably 0.33 - 10 rpm . The nozzle hub 6 is arranged at the distal end of the cleaning head 7 and is rotatable around an axis being perpendicular to the longitudinal direction of a vertical axis 9. One nozzle 8 is arranged on the cleaning head 7, configured for discharging jets of flushing liquids. A nozzle tip 11 is arranged at the distal end of the nozzle 8. In the embodiment shown in figure 1, one nozzle 8 is illustrated as being arranged on the cleaning head 7, however additional nozzles 8 may be arranged on the cleaning head 7.

The rotational movement of the rotatable joint 5 and the nozzle hub 6 ensures a large cleaning impact zone for the nozzle jets.

The flushing liquid pipe 3 further comprises a plate 2 configured to fit the tank opening, the plate 2 being arranged at a proximal end of the flushing liquid pipe 3 for mounting the cleaning device in a tank wall 14 of the oil tank 13 so as to extend into the oil tank 13. The plate 2 is configured to come in contact with a flange 15, typically being a 20" flange, arranged on a typically 20" pipe piece 16. The plate 2 is typically bolted to the flange 15.

The design of the tank-cleaning device according to the present invention, allows the device to be installed from the side of an oil tank, in a horizontal position. The design makes the cleaning device especially suited for Internal Floating Roof tanks and to protection of easily disruptive roof materials.

The 90 degrees bending of the extended flushing liquid pipe 4 interior to the tank (when the cleaning device is side mounted in an oil tank) enables an positioning of the down pipe 3a, nozzle head 7 and nozzle 8 as if the cleaning device was top mounted from the roof. This positioning of the cleaning device ensures a larger cleaning impact zone, to obtain efficient cleaning of the interior of the oil tank.

The tank cleaning device may further comprise driving means (not illustrated in figure 1) to rotate the rotatable joint 5 and the cleaning head 7 along the vertical axis 9. This rotational movement ensures a large cleaning impact zone for the nozzle jets. Preferably, the device comprises a switch (not illustrated in figure 1) to bring the rotatable joint 5 and the cleaning head 7 to rotate along the vertical axis 9, so as to ensure a remote controlling of the rotation of the rotatable joint 5 and the cleaning head 7, and to ensure a large cleaning impact zone for the nozzle jets.

The nozzle hub 6 is configured to rotate between two outer most positions, with a rotational speed being lower than 1 rpm, such as lower than 0.75 rpm, preferably lower than 0.5 rpm, to ensure a large cleaning impact zone for the nozzle jets. The cleaning device comprises driving means (not illustrated in figure 1) to rotate the nozzle hub 6, and a switch (not illustrated in figure 1) to ensure a specific rotational speed of the nozzle hub 6.

The nozzle tip 11 is replaceable arranged on the nozzle 8, so as to adapt for each specific tank design.

The cleaning device illustrated in figure 1 comprises a single nozzle 8 on the nozzle hub 6, but may in another embodiment (not shown) comprise a plurality of nozzles 8 arranged on the nozzle hub 6. As illustrated in figure 2, the cleaning device may further comprise driving means to rotate the rotatable joint 5 and the nozzle head 7. The driving means comprises a first rotational shaft 17 extending from a location exterior to the plate 2 and to the distal end of the flushing liquid pipe 3 parallel to the flushing liquid pipe 3,

- a second rotational shaft 18 extending from the distal end of the flushing liquid pipe 3 and to the rotational joint 5 at which the second rotational shaft 18 has a toothed connecting 20 to the rotational joint 5 so that rotation of the second rotational shaft 18 results in a rotation of the cleaning head 7.

The first rotational shaft 17 and second rotational shaft 18 are rotationally joined, preferably by a bevel gear 21 so that rotation of the first shaft result in a rotation of the second shaft and the cleaning head 7. The driving means further comprises an actuator 19 to rotate the first rotational shaft 17. The actuator is preferably arranged exterior to the oil tank. In another aspect, the present invention may relate to a method of cleaning of interior surfaces. The method utilize a side mounting of a cleaning device according to the present invention on an oil tank. On the basis of a sequence programming with multiple steps on individual wash programs, the movement of the cleaning device is controlled.

The method may comprise the step of adjusting the nozzle rotating velocity e.g. 0.5 - 5 m/s, such as 0.5 - 2.5 m/s, preferably 0.5 - 1.0 m/s at a cleaning circle impact. The cleaning circle impact zone has a diameter up to 10 meters, such as up to 20 meters, preferably up to 30 meter.

The method may further comprise the step of variable speed function, so as to provide a repeating sweep at the same horizontal positioning with a nozzle rotating velocity of 0.1 - 5 rpm, such as 0.1 - 2.5 rpm, preferably 0.1 - 1.0 rpm at wall, and in tank area. As the nozzle hub 6 rotates between two outer most positions, the nozzle 8 will discharge jets of liquids, which will be projected into the interior of the oil tank in an arc movement. This way of discharging liquid jets is referred to as sweeping. For high impact, the nozzle rotating velocity is 0,3 rpm (0,5m/s at end of jetting liquid). When the nozzles pass already clean areas, the nozzle speed is maximum 3,0 rpm so as to save cleaning time.

"Sweep" is a cleaning-function wherein the nozzle(s) 8 moves back and forth over the same cleaning area in the tank, in the same angle. The method may further comprise a step function with Stop/Go function split between combinations lower than 30 sec. combination, such as lower than 20 sec. combination, preferably lower than 10 sec. combination. The Stop/Go function is a rotation of the cleaning head 7, nozzle hub 6 and nozzle 8 and the rotation is performed in steps. When the nozzle 8 is not rotating, a high impact is achieved at the end of the jetting liquid.

The method may further comprise the step of discrete intermediate cleaning section with rapid movement to next cleaning area, allowing differential speed at each rotation. For the rapid movement the nozzle speed is 0,3rpm (0,5m/s at end of jetting liquid). To pass already clean areas, the nozzle speed is max speed 3,0 rpm to save cleaning time. In the discrete intermediate cleaning section, the nozzle 8 passes specific cleaning areas at various speeds.

The method may further comprise the step of Twin Nozzle Mode operation mode, wherein the nozzle hub 6 comprises two nozzles 8 arranged separately. The Twin Nozzle Mode operation mode is configured to secure a minimum interfering impact zones by alternating between nozzles directed into tank.

The method of cleaning of interior surfaces may utilizing one or more cleaning devices according to any of the embodiments of the present invention.

The cleaning devices may be simultaneously operated and may further comprise multiple nozzles 8. The nozzles 8 are configured to secure complete and minimum interfering sections of the entire oil tank during the nozzle movement pattern.

The minimum interfering section of the cleaning areas is achieved by adjusting the fluid supply to the nozzles 8 and by a detailed wash program.

The method may further comprise the step of supplying the nozzles 8 with variable washing liquid flows.

The method may also comprises the step of the cleaning device being moved towards the centre of the oil tank, so as to ensure a complete cleaning of the interior of the oil tank.

Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is set out by the accompanying claim set. In the context of the claims, the terms "comprising" or "comprises" do not exclude other possible elements or steps. Also, the mentioning of references such as "a" or "an" etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.

LIST OF REFERENCES

1 : Cleaning device

2: Plate

3: Flushing liquid pipe

3a : Down pipe

4: Extended flushing liquid pipe

5: Rotatable joint

6: Nozzle hub

7: Cleaning head

8: Nozzle

9: Vertical axis

10: Horizontal axis

11 : Nozzle tip

12: Bracket

13 : Oil tank

14: Tank wall

15: 20 " flange

16: 20 " pipe piece

17: First rotational shaft

18: Second rotational shaft

19: Actuator

20: Toothed connecting

21 : Bevel gear

Claims

1. A cleaning device (1) for cleaning interior surfaces of containers, such as oil- tanks (13), the cleaning device comprising

- a flushing liquid pipe (3) for the supply of liquid;

- an extended flushing liquid pipe (4), extending in a bend, such as 90 degrees, from the distal end of said flushing liquid pipe (3) and a down pipe (3a) extending from the distal end of said extending flushing liquid pipe (4) ;

- a cleaning head (7) arranged at the distal end of said down pipe (3a), so as to form the connection between a nozzle hub (6) and said down pipe (3a), said nozzle hub (6) is rotatable around the longitudinal direction of cleaning head (7);

- a rotatable joint (5) arranged between said down pipe (3a), and said cleaning head (7), said rotatable joint (5) being configured for being rotatable around a vertical axis (9);

- a nozzle hub (6) arranged at the distal end of said cleaning head (7), said nozzle hub (6) is rotatable around an axis being perpendicular to said longitudinal direction of a vertical axis (9);

- one or more nozzles (8), arranged on said cleaning head (7), configured for discharging jets of flushing liquids;

- a nozzle tip (11), being arranged at the distal end of said nozzle (8); driving means to rotate said rotatable joint (5) and said cleaning head (7) of said cleaning device (1) along the vertical axis (9); - said flushing liquid pipe (3) further comprising a plate (2) configured to fit a tank opening, said plate (2) arranged at a proximal end of said flushing liquid pipe (3) for mounting the cleaning device in a tank wall (14) of said oil tank (13) so as to extend into said oil tank (13), wherein

- said driving means comprises

- a first rotational shaft (17) extending from a location exterior to the plate (2) and to the distal end of the flushing liquid pipe (3) parallel to the flushing liquid pipe (3),

- a second rotational shaft (18) extending from the distal end of the

flushing liquid pipe (3) and to the rotational joint (5) at which the second rotational shaft (18) has a toothed connecting (20) to the rotational joint (5) so that rotation of the second rotational shaft (18) results in a rotation of the cleaning head (7)

- and wherein the first rotational shaft (17) and second rotational shaft

(18) are rotationally joined, preferably by a bevel gear (21) so that rotation of the first shaft result in a rotation of the second shaft and the cleaning head (7).

2. A cleaning device according to claim 1, wherein the driving means comprises an actuator (19) to rotate the first rotational shaft (17).

3. A cleaning device according to any of the preceding claims, further comprising a switch to bring said rotatabie joint (5) and said cleaning head (7) to rotate along the vertical axis (9).

4. A cleaning device according to any of the preceding claims, wherein the nozzle hub (6) is configured to rotate between two outer most positions, with a rotational speed being lower than 1 rpm, such as lower than 0.75 rpm, preferably lower than 0.5 rpm.

5. A cleaning device according to any of the preceding claims, wherein the nozzle tip (11) is replaceable arranged on said nozzle (8), so as to adapt for each specific tank design.

6. A cleaning device according to any of the preceding claims, comprising a single nozzle (8) on said nozzle hub (6).

7. A cleaning device according to any of the preceding claims, configured for use for internal floating roof tanks and to protection of easily disruptive roof materials.

8. A container, such as an oil tank, comprising one or more cleaning devices according to any of the claims 1-7, wherein said cleaning device is side mounted on said oil tank.

9. A method of cleaning of interior surfaces, the method utilize a side mounting of a cleaning device in appatures on an oil tank to be cleaned, on the basis of a sequence programming with multiple steps on individual wash programs, controlling the movement of the cleaning device.

10. A method of cleaning of interior surfaces according to claim 9, wherein the nozzle rotating velocity is 0.5 - 5 m/s, such as 0.5 - 2.5 m/s, preferably 0.5 - 1.0 m/s at a cleaning circle impact.

11. A method of cleaning of interior surfaces according to claim 9 or 10, wherein said cleaning circle impact zone has a diameter up to 10 meters, such as up to 20 meters, preferably up to 30 meter

12. A method of cleaning of interior surfaces according to claims 9-11, further comprising the step of variable speed function, so as to provide a repeating sweep at the same horizontal positioning with a nozzle rotating velocity of 0.1 - 5 rpm, such as 0.1 - 2.5 rpm, preferably 0.1 - 1.0 rpm at wall, and in tank area.

13. A method of cleaning of interior surfaces according to claims 9-12, further comprising a step function with Stop/Go function split between combinations lower than 30 sec. combination, such as lower than 20 sec. combination, preferably lower than 10 sec. combination.

14. A method of cleaning of interior surfaces according to claims 9-13, further comprising the step of discrete intermediate cleaning section with rapid movement to next cleaning spot allowing differential speed at each rotation.

15. A method of cleaning of interior surfaces according to claims 9-14, further comprising the step of Twin Nozzle Mode operation mode, the method comprising two nozzles (8) arranged separately on a nozzle hub (6), said Twin Nozzle Mode operation mode configured to secure a minimum interfering impact zones by alternating between nozzles directed into tank.

16. A method of cleaning of interior surfaces according to claims 9-15, utilizing one or more cleaning devices according to any of the claims 1-7.

17. A method of cleaning interior surfaces according to claims 9-16, utilizing one or more cleaning devices according to any of the claims 1-7, simultaneously operated, the cleaning device comprising multiple nozzles (8) configured to secure complete and minimum interfering sections of the entire tank.

18. A method of cleaning interior surfaces according to claims 9-17, utilizing one or more cleaning devices according to any of the claims 1-7, the cleaning device comprising variable washing liquid flow for multiple nozzles (8).