Oil-filled-cable adapter, oil-filled cable comprising an oil-filled-cable adapter, and system for cleaning an oil-filled cable

Abstract

The invention relates to an oil-filled-cable adapter comprising: a transition sleeve having an open end for connecting the oil-filled-cable adapter to an oil-filled cable, and a threaded end opposite the open end; a hose element, a first section of the hose element surrounding at least the open end; a first clamp which secures the first section of the hose element to the transition sleeve; and a second clamp for securing a second section of the hose element to the oil-filled cable. The invention also relates to an oil-filled cable which is connected to an oil-filled-cable adapter, and to a system for cleaning an oil-filled cable.

Description

[0001] Oil cable adapter, oil cable with an oil cable adapter and system for cleaning an oil cable

[0002] TECHNICAL AREA

[0003] The present disclosure relates to an oil cable adapter, an oil cable connected to an oil cable adapter, and a system for cleaning an oil cable.

[0004] BACKGROUND

[0005] An oil-filled cable is a special type of high-voltage cable that differs from conventional cables in its use of mineral oil for insulation and cooling of the inner conductor. The oil improves the insulating properties, thus enabling the transmission of higher voltages. At the same time, it acts as a coolant, preventing the cable from overheating. Oil-filled cables were once widely used in high-voltage applications, such as in power plants, substations, overhead lines, and underground cables. Today, however, they are rarely installed due to disadvantages related to the environment, maintenance, and cost. In many areas, they have been replaced by cables with plastic insulation, which are comparatively cheaper, require less maintenance, and are more environmentally friendly.

[0006] Many kilometers of disused oil-filled power lines are laid underground. To prevent the oil from seeping into the ground, the lines would have to be excavated and disposed of. However, this is very time-consuming and expensive.

[0007] To avoid excavating oil-filled cables, it is known to leave them underground and clean them there. A solution containing bacteria is pumped into the cable and left there for a predetermined time. The bacteria in the solution are able to use the hydrocarbons in the oil as an energy source and thus break them down. The solution, along with the absorbed oil, is then pumped out of the cable. This process can be repeated several times. Once cleaned, the cable can remain underground and does not need to be excavated.

[0008] A problem with the cleaning of oil-soaked cables described above is connecting the cable to a hose to pump the bacteria-laden fluid into or out of the cable. In known solutions, the hose is sealed to the cable using a sealant, and after use, the sealant is cut open and removed. However, this method is disadvantageous because the process is relatively time-consuming, and the sealant sometimes fails to provide the necessary seal and can only be used once.

[0009] SUMMARY OF THE REVELATION

[0010] The present disclosure is based on the task of providing an oil cable adapter for an oil cable, which enables a simple and reliable connection to an oil cable.

[0011] To solve this problem, an oil cable adapter is proposed comprising: a transition sleeve comprising an open end for connecting the oil cable adapter to an oil cable and a threaded end opposite the open end, a hose element wherein a first section of the hose element surrounds at least the open end, a first clamp that fastens the first section of the hose element to the transition sleeve, and a second clamp for fastening a second section of the hose element to the oil cable.

[0012] The oil-insulated cable adapter can generally be used with any type of oil-insulated cable to introduce or remove a liquid medium, such as a bacteria-containing fluid, from the cable. Examples of compatible oil-insulated cables include single-circuit oil-insulated cables, three-core oil-insulated cables, pressurized oil-insulated cables, oil-insulated power cables (SOIE), and gas-oil-insulated cables (GOEK).

[0013] The hose element can be partially fitted over the transition coupling, and the first clamp can secure the hose element to the transition coupling. Both the first and second clamps can be hose clamps. Alternatively, multiple clamps can be used instead of the first and / or second clamp.

[0014] The transition sleeve can be made of brass. Furthermore, the transition sleeve can have a cylindrical shape. For a reliable connection of the oil cable adapter to an oil cable, the open end of the transition sleeve can have a larger diameter than the threaded end. Additionally, for a reliable connection of the oil cable adapter to an oil cable, the open end of the transition sleeve can be designed as a flat surface.

[0015] To ensure a reliable connection between the transition sleeve and the hose element, the transition sleeve can have numerous grooves on its outer surface and on the first section of the hose element. For example, the transition sleeve can have six circumferential grooves with a depth of 1 to 3 mm.

[0016] The threaded end can be designed as an internal thread. Furthermore, the oil cable adapter can be equipped with a manual valve that is screwed into the threaded end. A hose can be attached to the other end of the manual valve. The manual valve allows for the manual control of the flow of fluid, particularly a fluid containing bacteria, into or out of the oil cable.

[0017] The hose element can be made of nitrile rubber, NBR. NBR is a material that is both oil-resistant and pressure-resistant.

[0018] Furthermore, a sealing compound can be applied between the transition sleeve and the first section of the hose element. The sealing compound, e.g., Loctite 567™, helps to create a reliable seal and prevent the ingress or leakage of water or other fluids, especially oil.

[0019] For reliable attachment of the hose element to the transition sleeve, the first section of the hose element can surround more than half of the transition sleeve.

[0020] The task posed at the beginning is also solved by an oil cable connected to an oil cable adapter, whereby the open end of the transition sleeve lies flush against one end of the oil cable.

[0021] The problem stated at the outset is further solved by an oil-filled cable connected to an oil-filled cable adapter, wherein the diameter of the open end of the transition sleeve is greater than or equal to the outer diameter of a paper insulation and a conductor of the oil-filled cable. In this case, the open end of the transition sleeve can cover all oil-carrying parts of the oil-filled cable at the open end of the cable. The problem stated at the outset is also solved by a system for cleaning an oil-filled cable, comprising one of the oil-filled cable adapters described above, a hose, one end of which is connected to the oil-filled cable adapter, and a pump, the other end of which is connected to the pump. The pump can be, for example, a diaphragm pump, a gear pump, a piston pump, a progressive cavity pump, or a submersible centrifugal pump.

[0022] Finally, the problem set out at the beginning is solved by a system for cleaning an oil cable, comprising one of the oil cable adapters described above, a hose wherein one end of the hose is connected to the oil cable adapter, and an oil separator wherein another end of the hose is connected to the oil separator.

[0023] The oil separator can be designed to separate oil from bacteria-containing liquid. To this end, the oil separator may include an inlet, a calming zone, coalescing baffles, an oil separation chamber, an outlet, and a sludge collection chamber. The oily water enters the oil separator through the inlet. In the calming zone, the flow velocity of the bacteria-containing liquid is reduced so that the oil droplets can settle on the surface. The coalescing baffles, made of metal or plastic, cause the small oil droplets to coalesce into larger droplets. The separated oil collects in the oil separation chamber. The cleaned, bacteria-containing liquid flows from the oil separator through the outlet into the storage tank. Solids such as sand and dirt collect in the sludge collection chamber.

[0024] The aspects and variants described above can be combined without this being explicitly stated. Each of the described design variants is therefore optional to any other design variant or combination thereof. This disclosure is thus not limited to the individual designs and variants in the described order or to any specific combination of aspects and design variants.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Further advantages, details, and features of the devices and systems described here will become apparent from the following description of exemplary embodiments and the figures. Fig. 1 shows a schematic representation of an exemplary embodiment of an oil cable adapter;

[0027] Fig. 2 shows a schematic representation of a first embodiment of a transition sleeve with a threaded end;

[0028] Fig. 3 shows a schematic representation of a first embodiment of a transition sleeve with an open end;

[0029] Fig. 4 shows a schematic representation of an embodiment of an oil cable adapter connected to an oil cable;

[0030] Fig. 5 shows a schematic representation of an embodiment of an oil cable; and

[0031] Fig. 6 shows a schematic representation of an embodiment of a system for cleaning an oil cable.

[0032] DETAILED DESCRIPTION

[0033] Fig. 1 shows a schematic representation of an embodiment of an oil cable adapter 5. The oil cable adapter 5 comprises a transition sleeve 10, a hose element 20, a first clamp 31 and a second clamp 32.

[0034] Fig. 2 shows the transition sleeve 10 of Fig. 1 with a centrally arranged threaded end 14 alone, and Fig. 3 shows the transition sleeve 10 of Fig. 1 with a centrally arranged open end 12, viewed from the opposite side.

[0035] The transition sleeve 10 has a cylindrical shape and is made of brass. The open end 12 of the transition sleeve 10 is designed for connecting the oil cable adapter 5 to an oil cable (not shown in Figures 1 to 3), and the threaded end 14 of the transition sleeve 10, which is formed as an internal thread, is designed for connecting the oil cable adapter 5 to a hand valve and / or a hose (not shown in Figures 1 to 3). There is an internal connection between the open end 12 and the threaded end 14, allowing a liquid, in particular a liquid containing bacteria, to flow through the transition sleeve 10. The open end 12 of the transition sleeve 10 has a larger diameter than the threaded end 14. Thus, the open end 12 is the beginning of a cylindrical borehole that extends centrally in the transition sleeve 10 to the thread (see thread end 14) on the opposite side of the transition sleeve 10.

[0036] The hose element 20 is made of nitrile rubber, NBR. A first section of the hose element 20 surrounds the open end 12 and part of the transition sleeve 10. The first clamp 31 secures the first section of the hose element 20 to the transition sleeve 10. The second clamp 32 is provided for securing a second section of the hose element 20, opposite the first section of the hose element 20, to an oil-filled cable (not shown in Figures 1 to 3). The clamps 31 and 32 can be tightened, for example, with screws (not shown in Figure 1).

[0037] On the outside at the open end 12, the transition sleeve 10 comprises a multitude of grooves 16. The grooves 16 improve the connection between the outside of the transition sleeve 10 and the inside of the hose element 20. Additionally, a sealing paste can be provided between the transition sleeve 10 and the hose element 20 in the area of ​​the grooves 16.

[0038] Figure 4 shows a schematic representation of an embodiment of an oil-filled cable adapter 5 connected to an oil-filled cable 90. The oil-filled cable adapter 5 is the same as shown in Figures 1 to 3. The dashed lines schematically illustrate the connection of the oil-filled cable adapter 5, i.e., the transition sleeve 10, to the oil-filled cable 90 within the oil-filled cable adapter 5. Thus, within the oil-filled cable adapter 5, the flat base of the transition sleeve 10 at the open end 12 rests against a flat base at one end of the oil-filled cable 90. The hose element 20 with the clamps 31 and 32 secures the transition sleeve 10 to the end of the oil-filled cable 90.

[0039] Fig. 5 shows a schematic representation of an embodiment of an oil cable 90. The oil cable 90 is the oil cable 90 shown in Fig. 4.

[0040] The oil-filled cable 90 comprises an aluminum waveguide with an oil channel 91, an inner conductive layer 92, oil-impregnated paper 93, an outer conductive layer 94, a lead sheath 95, a wound protective sheath 96, a pressure-resistant bandage 97, a wound protective sheath 98, and a polyvinyl chloride (PVC) protective sheath 99. The diameter of the open end 12 of the transition sleeve 10 is selected to correspond to the diameter of the aluminum waveguide with the oil channel 91, the inner conductive layer 92, and the oil-impregnated paper 93, so that a liquid containing bacteria can be pumped into the oil-filled cable 90 to the oil, or the liquid containing bacteria can be pumped out of the oil-filled cable 90 along with the oil absorbed from the oil-filled cable 90. In this case, the open end 12 of the transition sleeve 10 can cover all oil-carrying parts of the oil cable 90 at the open end of the oil cable 90.The diameter of the open end 12 of the transition sleeve 10 can also be chosen to be slightly, e.g. 1 cm, larger than the diameter of the aluminium waveguide with the oil channel 91, the inner conductive layer 92 and the paper with the oil impregnation 93.

[0041] A method for attaching the oil cable adapter 5 to an oil cable 90 comprises the following steps: A sealing paste is applied to the grooves 16 of the transition sleeve 10. The hose element 20 is slipped over the open end 12 of the transition sleeve 10 so that it covers approximately 2 / 3 of the transition sleeve 10. The open end 12 of the transition sleeve 10 is then placed flush against the end of the oil cable 90 by slipping the open end of the hose element 20 over the end of the oil cable 90. Subsequently, the first clamp 31 is attached over the hose element 20 at the transition sleeve 10, and the second clamp 32 is attached over the hose element 20 at the oil cable 90 and tightened.

[0042] To remove the oil cable adapter 5, simply loosen clamps 31 and 32 and pull the oil cable adapter 5 off the oil cable 90. The oil cable adapter 5 can then be reused.

[0043] Fig. 6 shows a schematic representation of an embodiment of a system for cleaning an oil cable 90.

[0044] The system comprises a tank 11, a pump 15, an oil separator 17, and a disposal tank 19. The tank 11, the pump 15, the oil separator 17, the disposal tank 19, and the oil cable 90 are connected to each other via pipes or hoses 2 and 3, respectively. The tank 11 includes an inlet hose 8 and an outlet hose 9.

[0045] A first oil cable adapter 5, which includes a hand valve 60, connects one end of hose 2 to the first end of oil cable 90. A second oil cable adapter 5 connects one end of hose 3 to the second end of oil cable 90. The first and second oil cable adapters 5 are the ones shown in Figures 1 to 4. The same oil cable adapter 5 can also be used successively for hose 2 and hose 3.

[0046] The following describes a procedure for cleaning the oil cable 90. A liquid containing bacteria is introduced into container 11. The bacteria in the liquid can be various types of bacteria capable of breaking down oil. These bacteria use the breakdown of oil as an energy source for their growth and metabolism.

[0047] The following bacteria can be used, among others: Pseudomonas spp.: This genus of bacteria includes various species that are able to break down a variety of hydrocarbons, including oils.

[0048] Alcanivorax spp.: These bacteria are specialized in the degradation of aliphatic hydrocarbons, which are commonly found in oils.

[0049] Rhodococcus spp.: This is another genus of bacteria known for its ability to break down hydrocarbons. Some species of Rhodococcus can degrade both aliphatic and aromatic hydrocarbons found in various types of oils.

[0050] Bacillus spp.: This genus of bacteria is known for its versatility and ability to break down a wide range of organic substances, including some oils.

[0051] Oleispira spp.: These bacteria are specialized in the degradation of hydrocarbons and are often found in environments affected by oil pollution.

[0052] Pump 15 pumps the bacteria-containing liquid from container 11 through hose 2, hand valve 60, and oil cable adapter 5 into the oil cable 90. The bacteria-containing liquid then remains in the oil cable 90 for a predetermined time (e.g., 24 hours). The bacteria in the bacteria-containing liquid use the hydrocarbons in the oil of the oil cable 90 as an energy source and break down the oil. Subsequently, the bacteria-containing liquid, along with the absorbed oil, is pumped from the oil cable 90 through oil cable adapter 5 and hose 3 into the oil separator 17. The oil separator 17 separates the oil from the bacteria-containing liquid into the disposal container 19. The remaining bacteria-containing liquid is pumped back into container 11 for reuse. The process for cleaning the oil cable 90 is then repeated until the oil cable 90 is sufficiently clean of oil.

[0053] The oil cable adapter, the oil cable connected to an oil cable adapter, and the oil cable cleaning system offer the following advantages: The oil cable adapter can be assembled quickly and is reusable. The oil cable adapter provides an improved seal, in particular preventing the oil cable adapter from bursting. Finally, oil runoff during assembly of the oil cable adapter to an oil cable can be reduced. In the presented examples, different features and functions of the present disclosure have been described separately as well as in certain combinations. However, it is understood that many of these features and functions can be freely combined with one another, unless explicitly excluded.

Claims

REQUIREMENTS 1. Oil cable adapter (5) comprising a transition sleeve (10) comprising an open end (12) for connecting the oil cable adapter (5) to an oil cable (90) and a threaded end (14) opposite the open end (12), a hose element (20) wherein a first section of the hose element (20) surrounds at least the open end (12), a first clamp (31) which secures the first section of the hose element (20) to the transition sleeve (10) and a second clamp (32) for securing a second section of the hose element (20) to the oil cable (90).

2. Oil cable adapter (5) according to claim 1, wherein the transition sleeve (10) has a cylindrical shape.

3. Oil cable adapter (5) according to one of the preceding claims, wherein the open end (12) of the transition sleeve (10) has a larger diameter than the threaded end (14).

4. Oil cable adapter (5) according to one of the preceding claims, wherein the open end (12) of the transition sleeve is designed as a flat base surface (18).

5. Oil cable adapter (5) according to one of the preceding claims, wherein the transition sleeve (10) comprises a plurality of grooves (16) on the outside and in the first section of the hose element (20).

6. Oil cable adapter (5) according to one of the preceding claims, wherein the transition sleeve (10) is made of brass.

7. Oil cable adapter (5) according to one of the preceding claims, wherein the threaded end (14) is designed as an internal thread.

8. Oil cable adapter (5) according to one of the preceding claims, wherein the hose element (20) is made of nitrile rubber, NBR.

9. Oil cable adapter (5) according to any one of the preceding claims, further comprising a sealing paste between the transition sleeve (10) and the first section of the hose element (20).

10. Oil cable adapter (5) according to one of the preceding claims, wherein the first section of the hose element (20) comprises more than half of the surrounds the transition sleeve (10).

11. Oil cable adapter (5) according to one of the preceding claims, further comprising a hand valve (60) that is screwed into the threaded end (14).

12. Oil cable (90) connected to an oil cable adapter (5) according to one of the preceding claims, wherein the open end (12) of the transition sleeve (10) is flush against one end of the oil cable (90).

13. Oil cable (90) according to claim 12, wherein the diameter of the open end (12) of the transition sleeve (10) is greater than or equal to an outer diameter of a paper insulation (93) and a conductor (91) of the oil cable (90).

14. System for cleaning an oil cable (90), comprising an oil cable adapter (5) according to any one of claims 1 to 11, a hose (2) wherein one end of the hose (2) is connected to the oil cable adapter (5), and a pump (15) wherein another end of the hose (2) is connected to the pump (15).

15. System for cleaning an oil cable (90), comprising an oil cable adapter (5) according to any one of claims 1 to 11, a hose (3) wherein one end of the hose (3) is connected to the oil cable adapter (5), and an oil separator (17) wherein another end of the hose (3) is connected to the oil separator (17).

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