EP3170941A1

EP3170941A1 - System for cleaning a septic tank of a vehicle and a method performing the same

Info

Publication number: EP3170941A1
Application number: EP15195736.2A
Authority: EP
Inventors: Wim Kuysters
Original assignee: LW-Group
Current assignee: LW-Group
Priority date: 2015-11-20
Filing date: 2015-11-20
Publication date: 2017-05-24

Abstract

A system (2, 200) for cleaning a septic tank (1) of a vehicle, comprising a first conduit (9) mounted at a first end to an access point (10) of the septic tank (1), a second conduit (6) arranged for discharging via the first conduit (9) the content of the septic tank (1), and a third conduit (7) arranged for supplying via the first conduit (9) a fluid to the septic tank (1). The system further comprises a flow control mechanism (12, 17, 18) for controlling the direction of flow between the second and third conduits (6, 7) and the first conduit (9). The second and third conduits (6, 7) are respectively connected at a second end to a discharge unit (3) for discharging the content of the septic tank (1) and to a fluid provision unit (4) for supplying a fluid under predetermined pressure force.

Description

Technical field

The present invention relates to a system for cleaning a septic tank, more specifically the present invention relates to a system and a method for cleaning the septic tank of a vehicle, such as a train, a recreational vehicle, or the like.

Background art

It is common to provide a toilet or toilets in a vehicle, e.g in a train, recreation vehicle, and the like for use during long journeys. These vehicles may further be equipped with a septic tank for holding the septic matter, fluid or solid, discharged by the toilet during the duration of journey. At frequent intervals the septic tank may be emptied in order to ensure that the toilet in the vehicle remains functional and further to avoid undesired odours from escaping from the septic tank into the airspace of the vehicle. Normally, the procedure of emptying the content of the septic tank involves discharging the content of the septic tank with the use of discharging unit or units into a conventional sewage system or into a septic matter receiving tank. For example, the discharging unit may be provided at certain locations to ease the operation for emptying the septic tank and further eliminate the need for the discharging unit and related equipment are required to be provided on the vehicle. For example, in the case of a septic tank located in a train the discharging unit or units may be provided at specific train stations, so that the septic tank of the train may be emptied while the train is stationary on the train platform or hangar. However, even after emptying the septic tank, solid septic matter tends to remain within the septic tank, which, if not removed, will start to accumulate every time the septic tank is emptied. The accumulation of the solid septic matter may over time restrict the septic tank space, resulting in the requirement for emptying the septic tank in more frequent intervals. Furthermore, the accumulation of solid septic matter within the septic tank may create undesired odours, which may escape from the septic tank through the toilet openings and into the air space of the vehicle. To remove the solid matter remaining in the septic tank, it is known after emptying the septic tank to inject a pressurised fluid within septic tank, which after a predetermined amount of time is drained using the discharging unit.
US4527295 discloses a septic tank flushing apparatus comprising a drain conduit and a fluid injecting conduit, each respectively connected to a dedicated access point of the septic tank. The septic tank access point dedicated to the fluid injecting conduit is provided with a nozzle tip having a number of openings arranged for directing the fluid within the septic tank with greater force so as to remove the solid septic matter. As such, the tank flushing apparatus of US4527295 can only be used with septic tanks that have at least two dedicated access points for connecting the discharge conduit and the fluid injecting conduit. However, a lot of septic tanks provided in vehicles have only a single access point. Therefore, the use of this apparatus is mainly restricted to septic tanks having dedicated access points as described in US4527295 .
CA2462064 discloses a waste contaminant-cleaning device arranged for removing waste material and debris from the septic tank of a recreation vehicle. The device is connected to the access point of the septic tank after the content of the septic tank has been discharged using a conventional discharging unit. In order to clean the septic tank, an outlet element having a T or Y shape is connected at one end to the access point of the septic tank, while an extension wand and an outlet hose are connected to the remaining two ends of the outlet element. The extension wand is connected to a water hose and is provided with water outlet perforations on its end which are disposed in the interior of the septic tank so as to inject pressurised fluid throughout the interior of the septic tank. The waste material then exits through the outlet hose connected to the outlet element into the sewage system. However, the device disclosed in CA2462064 cannot be used together with the discharging unit. As a result, emptying and cleaning the septic tank of a vehicle using the device of CA2462064 requires the use of two separate units, which can be expensive in terms of cost for buying the equipment, storage facilities and personnel required to operate the proposed device. Furthermore using two separate units for emptying and cleaning the septic tank requires a considerable amount of time for connecting and disconnecting the elements of each unit from the access point depending on the operation to be performed. As disclosed in the CA2462064 , the device is mainly directed to the cleaning of the septic tank of a recreation vehicle, where the owner of the recreation vehicle may use the device for cleaning the septic tank without any consideration with regards to the time taken to complete the cleaning operation of the septic tank. Therefore, the use of the proposed device is not considered to be practical in industrial applications where the cost and speed of performing the operations of emptying and cleaning the septic tank are of high importance. For example, in the case of emptying and cleaning the septic tank of a train at a train platform, both emptying and cleaning operations must be completed in a timely and cost effective manner.

Disclosure of the invention

It is an aim of the present invention to provide a system for cleaning the septic tank of a vehicle in an easy and quick manner.
This aim is achieved according to the invention with the system for cleaning a septic tank showing the technical characteristics of the first independent claim.
According to embodiments of the present invention, a system for cleaning the septic tank of a vehicle, such as a train is provided. The system comprises a first conduit arranged to be mounted at a first end to an access point of the septic tank for accessing an inner chamber of the septic tank, which is provided for holding septic matter both in fluid and solid form. The access point of the septic tank may be provided on a side wall of the septic tank but other locations are not excluded. A second conduit may be provided for discharging via the first conduit the content of the inner chamber, which second conduit is connected by means of a connector at a first end to a second end of the first conduit, the second end of the first conduit opposing the first end of the first conduit. A third conduit may be further provided for supplying via the first conduit a fluid to the inner chamber, which third conduit is connected by means of a connector at a first end to the second end of the first conduit and is arranged. The system may further comprise a flow control mechanism arranged for controlling the direction of flow between the second and third conduits and the first conduit, for example by selecting either one direction of flow, more in particular either supplying via the first and the third conduit the fluid to the inner chamber or discharging via the first and the second conduit the content of the inner chamber. Furthermore, the second and third conduits may be respectively connected at a second end, which is opposite their respective first end, to a discharge unit for discharging the content of the septic tank inner chamber and to a fluid provision unit for supplying a fluid under predetermined pressure force. It has been found that the provision of a flow control mechanism has the advantage that the operations of cleaning and discharging of the septic tank can be performed selectively one after the other without the need for disconnecting any of the discharge or fluid provision units from the access point of the septic tank. As a result, the operations of cleaning and discharging the content of the septic tank can be performed repeatedly in an easy and quick manner until the solid matter remaining in the septic tank is completely removed, which may extend the intervals between cleaning and emptying the septic tank, thereby reducing the cost associated with these operations. Moreover, the discharging and fluid provision units can be continuously connected to the system of the present invention, thus connecting the system to the septic tank only requires that the first end of the conduit is connected to the access point of the septic tank, thereby reducing the amount of time required for making the system operational.
According to embodiments of the present invention, the discharge unit may comprise a suction unit. The suction unit may be arranged for exerting a suction force for quickly discharging the content of the septic tank. The discharging unit may further comprise a septic matter receiving tank arranged for receiving the septic matter discharged from the inner chamber of the septic tank. As a result, cleaning and discharging the content of the septic tank may be performed in locations that have no direct access to a sewage system.
According to embodiments of the present invention, the fluid provision unit may comprise a pressure mechanism. The pressure mechanism may be arranged for applying a predetermined pressure force to the fluid supplied into the septic tank inner chamber. The pressure force may be varied so as to create a turbulent flow in the fluid supplied in the inner chamber of the septic tank, which may encourage the formation of vortexes having a rotational direction in the vertical or horizontal plane. The force of the vortexes formed in the fluid may be used to dislodge solid septic matter remaining in the septic tank, thus ensuring that the septic tank is thoroughly cleaned. The use of the force exerted by the vortexes for removing septic matter from the septic tank may eliminate the use of dangerous chemicals currently in use during the cleaning process, thus ensuring that the operation of cleaning the septic tank is more environmentally friendly.
According to embodiments of the present invention, the flow control mechanism may be arranged to move between a first position, where the flow through the second conduit remains open while the flow through the third conduit remains closed such that the content of the septic tank inner chamber are discharged via the first conduit , and a second position, where the flow of the third conduit remains open while the flow of the second conduit remains closed such that the pressurised fluid is supplied to the septic tank inner chamber via the first conduit. As a result the user of the system may selectively perform the operations of discharging or cleaning of the septic tank in an easy and quick manner by simply positioning the flow control mechanism in the relevant position.
According to embodiments of the present invention, the second and third conduit may be coupled to the first conduit via the flow control mechanism. For example the flow control mechanism may be provided at the second end of the first conduit. According to embodiments of the present invention, the flow control mechanism may comprise at least one valve. For example the at least one valve may be a three way valve comprising a first outlet arranged to be connected to the second end of the first conduit , a second outlet arranged to be connected to the first end of the second conduit and a third outlet arranged to be connected to the first end of the third conduit. The use of a three way valve may reduce the number of elements required for connecting all the different conduits of the system. Alternatively the flow control mechanism may be provided at each of the respective first ends of the second and third conduit. For example, the flow control mechanism may comprise at least two valves each positioned at the first end of the respectively the first and second conduit. In this case the first conduit may be provided with at least two connectors each arranged for respectively receiving the first ends of the second and third conduits.
According to embodiments of the present invention, the pressurised fluid supplied to the septic tank inner chamber via the third conduit portion may substantially comprise water. According to embodiments of the present invention, the temperature of the water may be varied for example between 2° C to 90°C, which may help in disclosing the solid septic matter from the inner chamber of the septic tank and further may encourage the formation of vortexes in the fluid supplied in the inner chamber of the septic tank.
According to embodiments of the present invention, the system comprises a vehicle, such as for example a train, with a septic tank, the septic tank comprising an access point, the first conduit being mounted to the access point of the septic tank with the first end.
It is another aim of the present invention to provide a method for cleaning the septic tank using the system according to the first aim of the present invention.
This aim is achieved according to the invention with a method comprising the steps of the second independent claim.
According to embodiments of the present invention, a method for cleaning a septic tank using the system according to the first aim of the present invention is provided. The method may comprise the steps of attaching the system for cleaning the septic tank according to embodiments of the present invention via the first end of the first conduit to the access point of the septic tank for accessing an inner chamber of the septic tank. Once the system is securely attached, the cleaning of the septic tank may start by positioning the flow control mechanism in the relevant position such that a pressurised fluid is supplied to the septic tank inner chamber through the third conduit. After a predetermined time the flow control mechanism may be positioned in the relevant position such that the fluid supplied in the septic tank inner chamber is discharged through the second conduit. According to embodiments of the present invention the steps of the method for cleaning the septic tank may be performed a number of times to ensure that the septic tank is thoroughly cleaned, thereby extending the intervals between cleaning and emptying the septic tank.
According to embodiments of the present invention, when starting from a full septic tank, the method may further comprise a number of steps for discharging the content of the septic tank, which may involve positioning the flow control mechanism in the relevant position and discharging the content of the septic tank inner chamber through the second conduit. According to embodiments of the present invention, the method steps for discharging the content of the septic tank may be performed before the method steps for cleaning the septic tank.
According to embodiments of the present invention the method for cleaning the septic tank may be applied to a septic tank of a train.

Brief description of the drawings

The invention will be further elucidated by means of the following description and the appended figures.

Figure 1 shows a perspective view of the system of the present invention connected to a septic tank of a vehicle according to embodiments of the present invention.
Figure 2 shows a cross-sectional view of the system of the present invention provided with an exemplified configuration for connecting the second and third conduit to the first conduit.
Figures 3 and 4 show examples of the operation of the system of the present invention respectively during emptying and cleaning of the septic tank.
Figure 5 shows a cross-sectional view of the system of the present invention provided with an exemplified alternative configuration for connecting the second and third conduits to the first conduit according to embodiments of the present invention.
Figures 6 and 7 show examples of the operation of the system of the present invention using the alternative configuration of figure 5 respectively during emptying and cleaning of the septic tank.
Figure 8 shows an example of a control panel positioned on the outside of the system of the present invention.
Figure 9 shows an example of the system of the present invention provided with means for moving the system to the desired location according to embodiments of the present invention.

Modes for carrying out the invention

The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention.
Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than described or illustrated herein.
Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein can operate in other orientations than described or illustrated herein.
Furthermore, the various embodiments, although referred to as "preferred" are to be construed as exemplary manners in which the invention may be implemented rather than as limiting the scope of the invention.
The term "comprising", used in the claims, should not be interpreted as being restricted to the elements or steps listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a device comprising A and B" should not be limited to devices consisting only of components A and B, rather with respect to the present invention, the only enumerated components of the device are A and B, and further the claim should be interpreted as including equivalents of those components.
Referring to figures 1 to 9, a system 2 for cleaning the septic tank 1 of a vehicle, such as a train, recreational vehicle and the like may be provided. The system 2 may be provided with a first conduit 9 a first end of which may be arranged to be connected to an access point 10 of the septic tank 1, which may be provided with an inner chamber 19 for holding the septic matter. A pipe or a tube 11 may be used for connecting the first end of the first conduit 9 to the access point 10 of the septic tank 1, which access point 10 may be positioned at a side wall of the septic tank 1. Alternatively, the first end of the first conduit 9 may be directly connected to the access point 10 of the septic tank 1. The system 9 may be provided with a second conduit 6 arranged for discharging via the first conduit 9 the content of the septic tank 1. As shown in figures 2 to 7, the second conduit 6 may be connected by means of a connector 14 or 24 at a first end to a second end of the first conduit 9, the second end of the first conduit 9 opposing the first end of the first conduit 9. A third conduit 7 may be provided for supplying via the first conduit 9 a fluid to the inner chamber of the septic tank 1, which may be connected by means of a connector 15 or 25 at a first end to the second end of the first conduit 9. The second conduit 6 and third conduit 7 may be connected at a respective second end to a discharging unit 3 and a fluid provision unit. Pipes or tubes 20 and 21 may be provided for connecting by means of connectors 8 the second conduit 6 to the discharging unit 3 and the third conduit 7 to the fluid provision unit 4. The pipes or tubes 20 and 21 may be extendible such that system 2 may be positioned away from the discharging unit 3 and fluid provision unit 4. Alternatively, the second conduit 6 and third conduit 7 may be directly connected respectively to the discharging unit 3 and fluid provision unit 4. The system 2 may be further provided with a flow control mechanism arranged for controlling the direction of flow between the second and third conduits 6 and 7 and the first conduit 9. The flow control mechanism may be operated by a control panel 5, which may be provided on the system 2 or in direct communication with the system 2. As shown in the example of figure 8, the control panel 5 may be provided with a number of control buttons 22 for controlling the operation of the system 2. Using a flow control mechanism 12 may have as an advantage that the system 2 may be used both for cleaning and discharging of the septic tank without the need for disconnecting any of the discharging unit 3 or fluid provision unit 4 from the access point 10 of the septic tank 1. As a result, the operations of cleaning and discharging can be performed repeatedly in an easy and quick manner until the solid matter remaining in the inner chamber of the septic tank 1 is completely removed. The complete removal of the solid matter remaining after discharging of the content of the septic tank 1 in the inner chamber may extend the intervals between cleaning and emptying the septic tank 1, thereby reducing the cost associated with these operations. Moreover, the system 2 of the present invention may allow the discharging unit 3 and fluid provision unit 4 to be continuously connected to the system of the present invention, thus connecting the system 2 to the septic tank 1 only requires that the first end of the first conduit 9 is connected to the access point 10 of the septic tank 1, thereby reducing the amount of time required for making the system 2 operational..
According to embodiments of the present invention, the discharging unit 3 may comprise a suction unit, which is not shown, arranged for providing a suction force so that the content of the septic tank 1 can be quickly discharged. Furthermore, the discharging unit may be provided with a septic matter receiving tank arranged for holding the septic matter discharged from the septic tank 1 inner chamber. The provision of a septic matter receiving tank may have as an advantage that the system 2 may be used in a location where there is no direct access to a sewage passageway.
According to embodiments of the present invention, the fluid provision unit 4 may be provided with a pressure mechanism, which is not shown. The pressure mechanism may be arranged for applying a predetermined pressure force to the fluid supplied into the septic tank 1 inner chamber. The pressure force may be varied so as to create a turbulent flow in the inner chamber of the septic tank causing the formation of vortexes in the fluid supplied in inner chamber of the septic tank 1. The force of the vortexes formed in the fluid may be used to dislodge solid septic matter remaining in the septic tank, thus ensuring that the septic tank is thoroughly cleaned. The use of vortexes for removing septic matter from the septic tank may eliminate the use of dangerous chemicals currently in use, thus making the operation of cleaning the septic tank 1 more environmentally friendly. However, chemicals can still be used for cleaning the septic tank 1.
As shown in figures 2 to 7, the flow control mechanism may be arranged to move between a first position A, where the flow through the second conduit 6 remains open while the flow through the third conduit 7 remains closed such that the content of the septic tank 1 inner chamber are discharged via the first conduit 9, and a second position B, where the flow of the third conduit 7 remains open while the flow of the second conduit 6 remains closed such that the pressurised fluid is supplied to the septic tank 1 inner chamber via the first conduit 9. As shown in figure 2, the second conduit 6 and third conduit 7 may be coupled to the first conduit 9 via the flow control mechanism 12. For example, the flow control mechanism 12 may comprise at least one valve, such as a three way valve, which may have a first outlet arranged to be connected by means of a connector 13 to the second end of the first conduit 9, a second outlet arranged to be connected by means of a connector 14 to the first end of the second conduit 6 and a third outlet arranged to be connected by means of a third connector 15 to the first end of the third conduit 7. The at least one valve may be further provided with an actuator 16, which may be used for manually operating the valve and for indicating the position of the valve. Preferably, the flow control mechanism 12 may be operated through a control panel 5 which may be located on the system 2, as shown in figure 8, or in a centralised location and in direct communication with the system 2 . Furthermore, a processor, for example a Programmable Logic Controller (PLC), may be provided for controlling by means of a software program the operation of the system 2 during emptying and cleaning the content of the septic tank 1. For example, the processor may be supplied with a specific software program which contains instructions on operating the flow control mechanism 12 during the cleaning and discharging of the septic tank 1 content. For example, the software program may contain instruction on how to operate the flow control mechanism 12 during the cleaning operation by for example alternating at predetermined intervals the position of the flow control mechanism 12 between the first position and second position so as to create a greater turbulence in the fluid supplied in the septic tank 1, which may result in the removal of the septic matter remaining in the septic tank 1. For example, the intervals may be determined such that second position of the flow control mechanism 12 is maintained sufficiently long to sufficiently fill the septic tank 1 with the fluid, for example substantially fully or even fully filling the septic tank 1, and is switched to the first position upon sufficiently filling the septic tank 1, preferably right after sufficiently filling the septic tank 1, for example when the fluid in the septic tank 1 is still experiencing turbulence from filling of the septic tank 1, the turbulence improving the cleaning of the septic tank 1. The intervals may be further determined such that the first position of the flow control mechanism 12 is maintained sufficiently long to sufficiently empty the septic tank 1, for example substantially completely or even completely emptying the septic tank 1. According to further embodiments, the software program contains instructions to switch back to the second position upon sufficiently emptying the septic tank 1, preferably right after sufficiently emptying the septic tank 1. This way, several cycles of filling and emptying the septic tank with the fluid can be obtained, which improves cleaning of the septic tank 1.
Figure 3 shows an example of operating the system 2 for discharging the content of the inner chamber of the septic tank 1. In order to perform this operation, the flow control mechanism 12 is positioned in the relevant position, which in this example is position "A", such that the flow between the second conduit 6 and the first conduit 9 remains open while the flow between the third conduit 7 and the first conduit 9 remains closed. In this position the suction unit of the discharging unit 3 is operated such that a suction force is applied to the content of the septic tank 1, thereby causing the septic matter to be discharged in the direction of the arrows via the first conduit 9.
Figure 4 shows an example of operating the system 2 for cleaning the inner chamber of the septic tank 1. In this case, the flow control mechanism 12 is positioned in the relevant position, which in this example may be considered to be the position B, such that the flow between the third conduit 7 and the first conduit 9 remains open while the flow between the second conduit 6 and the third conduit 9 remains closed. In this position, the fluid provision unit provides a pressurised fluid into the inner chamber of the septic tank 1 via the first conduit 9. The pressurised fluid may substantially comprise water, which may be recycled or reclaimed water in order to minimise the use of fresh water. As previously discussed, the pressure of the fluid supplied into the inner chamber of the septic tank 1 may be varied so as to create a turbulent flow in the fluid supplied to the septic tank in order to encourage the formation of vortexes, the force of which may be used for dislodging the solid septic matter remaining in the inner chamber of the septic tank 1. Furthermore, the temperature of the fluid supplied may be varied during the cleaning process. For example the temperature of the fluid supplied may be in the range between 2°C and 90° C. After a predetermined time, the flow control mechanism may be positioned back to the position A such that the content of the septic tank 1 are discharge via the second conduit 6. The procedure may be repeated a number of times until the septic tank is satisfactory cleaned. This procedure is preferably carried out by means of electronic equipment, which may for example be controlled via a control panel 5 which may be located on the system 2 or in from a control panel located in a centralised location. For example, the procedure for alternating the flow control mechanism 12 between the first and second position during cleaning of the septic tank 1 may be performed by a processor, for example a PLC, supplied with a software program, as previously discussed. However, this procedure can also be carried manually by an operator by manually positioning the flow control mechanism 12 in the relevant position via the actuator 16.
Figure 5 shows an example of a system 200 having an alternative configuration for connecting the second conduit 6 and third conduit 7 to the first conduit 9. The only difference with the system 2 shown in figures 2 to 4 is that the second conduit 6 and third conduit 7 may be provided each with a flow control mechanism 17 and 18 at their respective first ends, which may comprise a valve such as a two way valve. The first conduit 9 may be provided at a second end with two connectors 24 and 25 each arranged for respectively receiving the first ends of the second and third conduits 6 and 7. Figure 6 illustrates an example of discharging the content of the septic tank 1 using the system 200. In this case, in order to discharge the content of the septic tank 1 the flow control mechanism 17 is positioned at the relevant position, which in this case is position A, so that the flow between the second conduit 6 and the first conduit 9 remains open, while the flow control mechanism 18 is positioned at the relevant position, which in this case is position B, so that the flow between the third conduit 7 and the first conduit 9 remains closed. With the flow mechanisms 17 and 18 in their relevant position, the content of the septic tank 1 is discharged by operating the suction unit of the discharging unit 3. Once the content of the septic tank 1 has been discharged, the cleaning operation may be performed by positioning the flow mechanism 17 and 18 in their relevant positions so that the fluid under pressured may be supplied to the septic tank via the third conduit 7, as shown in figure 7. The cleaning and discharging operations may be repeatedly performed one after the other so as to ensure that the solid septic matter has been completely removed from the septic tank 1.
According to embodiments of the present invention, the system 2 may be provided with means 30 for moving the system to the desired location where the vehicle is stationed. For example the system 2 may be positioned in a platform 31 comprising wheels so that the system can be easily transported to the location where the vehicle is station, such as in a train platform or hangar, and the like.

Claims

A system (2, 200) for cleaning a septic tank (1), the system comprising :
a first conduit (9) arranged to be mounted at a first end to an access point (10) of the septic tank (1) for accessing an inner chamber (19) of the septic tank (1) provided for holding septic matter;

a second conduit (6) connected at a first end to a second end of the first conduit (9), the second end of the first conduit (9) opposing the first end of the first conduit (9), for discharging via the first conduit (9) the content of the inner chamber; and

a third conduit (7) connected at a first end to the second end of the first conduit (9) for supplying via the first conduit (9) a fluid to the inner chamber;

a connector (13, 14, 15, 24, 25) for connecting the second and third conduits (6, 7) to the first conduit (9);

characterised in that the system (2, 200) further comprises a flow control mechanism (12, 17, 18) arranged for controlling the direction of flow between the second and third conduits (6, 7) and the first conduit (9), and in that the second and third conduits (6, 7) are respectively connected at a second end, which is opposite their respective first end, to a discharge unit (3) for discharging the content of the septic tank (1) inner chamber and to a fluid provision unit (4) for supplying a fluid under predetermined pressure force.
The system (2, 200) according to claim 1, wherein the discharge unit (3) comprises a suction unit.
The system (2, 200) according to claim 1 or 2, wherein the discharge unit (3) further comprises a septic matter receiving tank arranged for receiving the septic matter discharged from the septic tank (1) inner chamber.
The system (2, 200) according to any one of the preceding claims, wherein the fluid provision unit (4) comprises a pressure mechanism.
The system (2, 200) according to any one of the preceding claims, wherein the flow control mechanism (12, 17, 18) is arranged to move between a first position, where the flow through the second conduit (6) remains open while the flow through the third conduit (7) remains closed such that the content of the septic tank (1) inner chamber are discharged via the first conduit (9), and a second position, where the flow of the third conduit (7) remains open while the flow of the second conduit (6) remains closed such that the pressurised fluid is supplied to the septic tank (1) inner chamber via the first conduit (9).
The system (2, 200) according to any one of the preceding claims, wherein the second and third conduits (6, 7) are coupled to the second end of the first conduit (9) via the flow control mechanism (12, 17, 18).
The system (2, 200) according to claim 6, wherein the flow control mechanism (12) comprises at least one valve comprising a first outlet arranged to be connected by a connector (13) to the second end of the first conduit (9), a second outlet arranged to be connected by a connector (14) to the first end of the second conduit (6) and a third outlet arranged to be connected to the first end of the third conduit (7).
The system (2, 200) according to any one of claims 1 to 6, wherein the flow control mechanism comprises two valves (17, 18) each positioned at the first ends of the first and second conduit (6, 7).
The system (2, 200) according to claim 8, wherein the first conduit (9) comprises at least two connectors (24, 25) each arranged for respectively receiving the first ends of the second and third conduits (6, 7).
The system (2, 200) according to any one of the preceding claims, wherein the pressurised fluid supplied to the septic tank (1) inner chamber substantially comprises water.
A method for cleaning a septic tank (1) using the system (2, 200) according to any one of claims 1 to 10, the method comprising the steps of:
a) attaching the system (2, 200) according to any one of the 1 to 10 via the first end of the first conduit (9) to the access point (10) of the septic tank (1) for accessing an inner chamber (19) of the septic tank (1);

b) positioning the flow control mechanism (12, 17, 18) in the relevant position such that a pressurised fluid is supplied to the inner chamber of the septic tank (1) through the third conduit (7); and

c) positioning the flow control mechanism (12, 17, 18) in the relevant position such that the fluid supplied in the inner chamber of the septic tank (1) is discharged through the second conduit (6).
The method according to claim 11, wherein the method steps b) and c) for cleaning the septic tank (1) are repeated a number of times.
The method according to claim 11 or 12, wherein when starting from a full septic tank the method further comprises the steps of :
d) positioning the flow control mechanism (12, 17, 18) in the relevant position; and

e) discharging the content of the septic tank (1) inner chamber through the second conduit (6).
The method according to claim 13, wherein the steps d) and e) are performed after step a) and before step b).
A method for cleaning a septic tank (1) of a train using the method according to claims 11 to 14.