WO2008130289A1

WO2008130289A1 - Waste collection

Info

Publication number: WO2008130289A1
Application number: PCT/SE2007/000387
Authority: WO
Inventors: Rune Hammar; Mattias Pihl
Original assignee: Envac Ab
Priority date: 2007-04-20
Filing date: 2007-04-20
Publication date: 2008-10-30
Also published as: EP2142449B1; DK2142449T3; ES2621178T3; WO2008130289A8; EP2142449A4; EP2142449A1

Abstract

In a mobile type waste collection system (1), electrical power for system auxiliary equipment (20) is produced onboard a vacuum vehicle (10) of the system for supplying said produced electrical power from the vehicle to the auxiliary equipment of a storage tank (2.2, 2.3, 2.4) in the system through an electrical connection interface associated with a waste docking station (30).

Description

TITLE: WASTE COLLECTION

TECHNICAL FIELD

The present invention relates generally to the collection of waste, and specifically relates to methods and systems for vacuum operated waste collection of a mobile type.

BACKGROUND

In mobile type waste collection systems waste deposited at different waste collection points inside or outside buildings is gathered in respective waste storage tanks or containers that are emptied by means of vacuum-equipped vehicles. Said vehicles, the so called vacuum-trucks, are connectable to docking stations that in turn communicate with one or several such waste storage tanks through waste pipe systems.

In recent years the storage capacity of such waste storage tanks has been gradually increased in order to cope with the increasing waste volumes deposited at many collection points between emptying sequences. These increasing waste volumes of the storage tanks have necessitated the development of equipment and designs for securing rapid and safe emptying of the large storage tank volumes without any risk of blockage in the tanks or in the pipe systems. One such recent improvement is the provision of an agitator, normally in the shape of an electrically powered feed screw, near the bottom of at least large, heavily loaded storage tanks.

In the conventional mobile type systems efforts have been made, where at all possible, to supply electric power to the above mentioned agitators from available supply points in the area where the system is operated. This means that for storage tanks receiving deposited waste from outdoor collection points, it has in most cases been necessary to draw long, expensive electric supply lines from the available supply points to the actual waste storage tanks. Another potential problem with regard to mobile waste collection systems of this kind is the correlation of the electric power supply with the different housing estates, possibly with different owners, that frequently share one and the same waste deposit and collection station.

SUMMARY

The invention overcomes the above problems in an efficient and satisfactory manner. It is a general object of the invention to provide an improved, efficient and convenient power supply for a mobile type waste collection system.

In particular, it is an object of the invention to provide an improved method of supplying power to auxiliary equipment for a waste storage tank of a mobile type waste collection system.

In particular, it is another object of the invention to provide a mobile type waste collection system having an improved power supply for auxiliary equipment of at least some of the waste storage tanks of the system.

It is yet another object of the invention to provide an improved vacuum vehicle for use in the system of the invention.

These and further objects of the invention are met by the invention as defined in the appended patent claims.

Briefly, the invention provides methods and arrangements for integrating the power supply for auxiliary equipment of a waste collection system, in the actual system.

Specifically, the invention provides methods and arrangements for producing electrical power for the system auxiliary equipment onboard a vacuum vehicle of the system and for supplying said produced electrical power from the vehicle to the auxiliary equipment of a storage tank in the system through an interface associated with a waste docking station. One advantage of the suggested methods and arrangements is that no external power connections will be required, with an associated reduction of the costs for and problems related to auxiliary power installations.

In embodiments of the invention, where a vacuum source of the vehicle is connectable to a pipe connecting interface of a docking station through a vehicle-carried pipe, methods and arrange- ments are provided for establishing a convenient or even an automatic connection of the auxiliary electrical power from the vehicle to the auxiliary equipment by integrating an electrical connecting interface in the docking station or in the actual pipe connecting interface. In further embodiments of the invention that are intended for use especially in systems where some storage tanks of the system are equipped with rotary emptying agitators, provisions are made for identifying the docking station or the actual storage tank connected to the vehicle and for starting the production of auxiliary electrical power onboard the vehicle only when a waste storage tank having an agitator is connected for emptying.

Advantages offered by the present invention, in addition to those described above, will be readily appreciated upon reading the below detailed description of embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with further objects and advantages thereof, may best be understood by referring to the following description taken together with the accompanying drawings, in which:

Fig. 1 is an exemplifying, schematical illustration of a mobile type waste collection system;

Fig. 2 is a schematical illustration of a waste storage tank of the system of Fig. 1, with a waste agitator provided for the storage tank;

Fig. 3 is a partly schematical illustration of an embodiment of the power supply system of the invention;

Fig. 4 is a very schematical illustration of the general outline of a connecting interface of the invention;

Fig. 5 is a schematical illustration of an embodiment of a tank identification arrangement of the invention;

Fig. 6 A is a detail view of a vacuum source for the vacuum vehicle of the invention; and

Fig. 6B is a schematical illustration of an embodiment of a vacuum fan control arrangement.

DETAILED DESCRIPTION

The invention will now be explained with reference to an exemplifying embodiment of the inventive system and method, illustrated particularly in drawing figures 3-5. The illustrated, exemplifying embodiment relates to an application of the inventive solution to an exemplary waste collection system of the mobile type that is schematically illustrated in drawing figures 1-2. However, it shall be emphasized that the invention is in no way restricted to that particular application.

Fig. 1 very schematically illustrates the use of a conventional mobile type waste collection system 1 in an imaginary residential or other area where waste is deposited at different kinds of waste collection points 4.1; 4.2, 4.4, for collection and temporary storage in waste storage tanks or containers 2.2, 2.3, 2.4; 3.1, 3.4. Specifically, in said system are included indoor and outdoor types of collection points 4.4; 4.1 and 4.2, respectively. The indoor type 4.1; 4.4 is normally situated in a basement of a building 6 and receives waste deposited in waste chutes extending through several stories of the building 6, as is well known within this technical field. The outdoor type of collection point 4.2 is situated outdoors and comprises an underground waste storage tank 2.2, 2.3, 2.4 to which waste is deposited through a short chute 8 (see Fig. 2) extending a short distance up to an insertion opening 9 above ground G.

Among the waste storage tanks, a distinction is made between a first type of tanks 2.2, 2.3, 2.4 having a rotatable agitator 20 with drive motor 21 for assisting in the emptying, predominantly of larger and/or heavily loaded tanks of the system; and a second type of tanks 3.1, 3.4 having no such auxiliary emptying equipment. One or several of the waste collection points 4.4; 4.2; 4.1, or specifically their tanks, are connected to a corresponding docking station 30 through the respective waste transport pipes 5.1, 5.2, 5.3, 5.4. In the case where several tanks, such as the tanks 2.2 and 2.4, 3.4, respectively, are connected to one and the same docking station 30, branch valves 7 are provided in the transport pipes 5.2, 5.4 to allow for the separate connection of each tank to the docking station. The tanks of the system are sequentially emptied by means of a vacuum vehicle 10 having a vehicle-mounted vacuum source 11 and being driven along a drive way DW of the area for connection to the respective, spaced docking stations 30, as will be described.

Fig. 2 likewise very schematically illustrates one such known waste storage tank 2.2, 2.3, 2.4 of the system 1 and its connection, through a stationary pipe system 5.2, 5.3, 5.4, a docking station

30 and a vehicle-mounted vacuum pipe 12, to the vacuum truck 10 for emptying. With the vacuum truck 10 communicating with the pipe system 5.2, 5.3, 5.4 through the vacuum pipe 12 and the docking station 30, emptying of the tank 2.2, 2.3, 2.4 in question is carried out by activating the vacuum source 11, opening a respective tank discharge valve 19 - and in the relevant cases a corresponding branch valve 7 (see Fig. 1) - and selectively activating the agitator 20 when the emptying conditions so require. For further details regarding the preferable ways of operating the agitators 20 during emptying, reference is made to our International PCT-appli- cation No. WO 2006/135296. In the conventional mobile system 1, the power supply for the agitator 20 drive motors 21 is a great concern due to the extensive cost and labor involved in laying stationary connection lines to the different, quite significantly spaced apart collection points 4.1; 4.4; 4.2 and also due to the initially mentioned problems of coordinating the electric power supply for the different collection points and a varying number of housing estate owners.

To overcome such problems, the invention now suggests providing a system integrated electric power supply for auxiliary equipment employed at the collection points. In the embodiment illustrated in Fig. 3 said auxiliary equipment is an agitator 20 for a storage tank 2.2, 2.3, 2.4 of a collection point 4.2; 4.4 in the waste collection system 1. However, the invention shall not be restricted thereby, since the inventive integrated power supply may likewise be used for powering other auxiliary equipment employed at the collection points, such as valves etc. In particular the invention suggests producing auxiliary electrical power onboard the vacuum vehicle 10 used for emptying the system storage tanks at regular inter- vals. Said produced auxiliary electrical power is then supplied from the vehicle to an electrical connecting interface at or near a vehicle waste pipe docking station and from the connecting interface to said tank auxiliary equipment. Thereby, exceptional advantages are obtained compared to the conventional system, since the electric power source is moved with the vehicle to each docking station and since the required electrical power connection lines are limited to the connection lines from the docking stations and to the respective collection point. Said connection lines may preferably be laid down alongside of and simultaneously with the stationary waste pipes for the collection points/storage tanks.

In an embodiment of the inventive method wherein the vacuum source of the vacuum vehicle is releasably connected to a pipe connecting interface at the docking station through a vehicle- carried pipe, a convenient or alternatively even automatic connection of the auxiliary electrical power from the vehicle to the auxiliary equipment is provided by integrating the electrical connecting interface in the docking station or in the actual pipe connecting interface, respectively. In waste collection systems comprising several waste storage tanks that are emptied through allotted docking stations and in which not all tanks are provided with an agitator, or other auxiliary equipment requiring electrical power supply, the docking station or the actual storage tank being connected to the vehicle is identified in connection with each tank emptying procedure. Furthermore, the production of auxiliary electrical power onboard the vehicle is started only when an identified waste storage tank provided with an agitator is to be emptied through said docking station or alternatively when the vehicle 10 is connected to such a docking station. An exemplary embodiment of a method and means for performing such identification is described below, in association with Fig. 5.

A presently preferred embodiment of a vacuum operated waste collection system 1 according to the invention will now be described with reference to Figs. 3-5. Like in the conventional system, one or several waste storage tanks 2.2; 2.3; 2.4 of a number of waste collection points 4.4; 4.2 are connected through stationary waste pipe systems 5.2; 5.3; 5.4 to an allotted waste pipe docking station 30. A vehicle 10 carrying a vacuum source 11 is selectively connectable to each docking station 30 through a vehicle carried waste pipe 12. Some tanks 2.2; 2.3; 2.4 of the system have a waste agitator 20 being supported for rotation therein. The agitators are rotated by a drive motor 21 being electrically powered, hi the inventive system a generator 13 for producing auxiliary electrical power AEP is mounted on the vehicle 10, preferably supported on insulating rubber feet 14.

The generator 13 is connectable through an electrical power supply line 18.1 supported on the vehicle, to an electrical connection interface 34 (see FIG: 4) provided in the vicinity of the respective waste pipe docking station 30. From the electrical connection interface 34 the produced auxiliary electrical power AEP is supplied to the agitator 20 of the respective storage tank 2.2; 2.3; 2.4 through a stationary power line 18.2 extended from the connection interface 34 to the electric drive motor 21 for rotating the agitator 20. Specifically, in the illustrated embodiment, the vacuum source 11 of the vehicle 10 is releasably connectable to a first pipe connector element 32 of a pipe connecting interface 31 of the docking station 30 through the vehicle-carried pipe 12 having a second pipe connector element 33, as is conventional in this technique. According to this embodiment of the invention a practical or con- venient connection of the auxiliary electrical power AEP from the vehicle to the auxiliary equipment 20 is thereby established by integrating the electrical connecting interface 34 in the actual docking station 30. In a further, not illustrated development the electrical connection interface 34 and the pipe connecting interface 31 may be formed as a unit, permitting automatic connection of the auxiliary electrical power AEP when the pipe connection is performed. With such a configuration, the electrical connection will be established without any separate manual maneuvering.

In a further development of the invention, for use in waste collection systems 1 comprising waste storage tanks 2.2; 2.3; 2.4 provided with an agitator 20, or other auxiliary equipment, as well as storage tanks 3.1; 3.4 that lack such an agitator, it is proposed to identify, in connection with each tank emptying procedure, the actual docking station 30 being connected to the vehicle 10 for emptying and by starting the production of auxiliary electrical power

AEP onboard the vehicle only when said identified docking station 30 contains a waste storage tank 2.2; 2.3; 2.4 being provided with an agitator 20. In a further development of this embodiment, that will be discussed below with reference to FIG. 5, it will naturally also be possible to alternatively identify the actual waste storage tank 3.1; 3.4; 2.2; 2.3; 2.4 that is to be emptied through the respective docking station 30 and to start the production of auxiliary electrical power AEP onboard the vehicle 10 only when said identified waste storage tank 2.2; 2.3; 2.4 is provided with an agitator 20.

In a practical embodiment, the generator 13 delivers nominally 3 IcW, 400V AC, and for security reasons the generator 13 is provided with motor protection, load loss and short circuit, as well as a residual current operated circuit-breaker. Preferably, the auxiliary electrical power AEP is produced by means of a hydraulically driven generator 13 carried onboard the vehicle 10, whereby said hydraulic drive power for the generator will be supplied from a power take-off of a propulsion system of the vehicle 10 in a manner that is obvious to the skilled practitioner and that will therefore not be described in detail herein. As is indicated in Fig. 3 the auxiliary electrical power producing generator 13 must also be grounded by means of a grounding line 19 connected to the vehicle 10 through the electrical connecting interface 34. The grounding line from the connecting interface 34 to the vehicle is normally integrated in the supply line 18.1 and has therefore not been specifically illustrated. In Fig. 4 is very schematically illustrated the basic principles of a pipe connecting interface 31 for use in the system 1 of the invention. The pipe connecting interface 31 consists of the above mentioned first and second pipe connector elements 32 and 33, respectively. Said connector elements 32, 33 are of any known quick-connection type to be easily mutually connectable to provide a secure, sealed and air-tight connection for the transfer of waste in the air stream produced by the vacuum source 11. Such connector elements are well known within the art and will therefore not be described or illustrated in detail herein. Fig. 4 illustrates the embodiment where the electrical interface 34 is physically integrated in the docking station 30, and likewise only very schematically shows a first connector element 34A connected to the vehicle supported power supply line 18.1 and a second connector element 34B connected to the stationary power line 18.2. Said electrical connector elements 34A and 34B may likewise be of any known quick- connection type and will therefore not be shown or described in detail herein, rn a further, not specifically illustrated development of the invention, the electrical connection interface 34 may be physically or functionally integrated in the actual pipe connecting interface 31 of the docking station 30 for establishing an automatic connection of the supply of auxiliary electrical power AEP from the vehicle to the auxiliary equipment 20.

In a preferred further development of the invention each waste storage tank 3.1; 3.4; 2.2; 2.3; 2.4 in the system 1 is identified so that the generator 13 will be started only when a storage tank 2.2; 2.3; 2.4 requiring auxiliary power is connected for emptying, as was briefly indicated above. With reference to FIG. 5, which is a schematical illustration of a practical embodiment of a storage tank identification arrangement of the invention, the storage tank identification is performed in the following manner. Each waste storage tank 3.1; 3.4; 2.2; 2.3; 2.4 of the system 1 is conventionally equipped with a tank control box TCB through which several tank control functions are performed in cooperation with a likewise conventional vacuum truck PLC, as is very schematically indicated in FIG. 5. For further details of such possible further waste storage tank control functions, reference is made to our above mentioned International PCT-applicationNo. WO 2006/135296.

For the purposes of this further development of present invention, the tank control box TCB of each waste storage tank is equipped with an I/O-device 35 having a non- volatile RAM- memory 36, which is a memory that does not loose data when power is switched off. This memory 36 has a default factory value. The first time a vacuum truck 10 connects to the docking stations 30 of a system installation, unique identification data, such as identification numbers, is saved in the non- volatile RAM-memory 36 of each of the distributed I/O-devices 35 of the tank control boxes TCB of the system 1. When the truck 10 connects to the system 1 after the first time, a control system (not specifically illustrated) in the vacuum truck PLC reads the identification data saved in the I/O-device 35 of the connected waste storage tank. In this way the control system retrieves identification of the currently connected tank. Specifically, the identification numbers are supplied to and retrieved from the respective tank control boxes by the vacuum truck PLC, through a connection line 37 that may be automatically connected through the electrical connecting interface 34 or alternatively through the pipe connecting interface 31 of the respective docking station 30. When the vacuum truck PLC control system has identified that a connected waste tank is equipped with an agitator or other equipment requiring auxiliary power, activation of the generator 13 is initiated through a signal line 38. In this manner it is secured that the generator 13 is only started when the vacuum track 10 is actually connected to a waste tank requiring auxiliary electric power.

hi Fig. 6A is illustrated an exemplary vacuum fan 40 for use as the vacuum source 11 in the vacuum vehicle 10 of the invention. Conventionally, the vacuum fan 40 comprises a fan housing 41 with an impeller (not shown) rotated by a hydraulic motor 42 that will normally be driven through the vehicle propulsion (likewise not shown). The impeller sucks in air through a fan inlet channel 43 that in the waste collection system application communicates with the vehicle carried waste pipe 12 to create vacuum in said waste pipe and ultimately in a waste storage container 2.2, 2.3, 2.4; 3.1 or 3.4 and exhausts air to the atmosphere through a fan outlet channel 44 and an exhaust air silencer 45. The vacuum fan 40 of the invention is further characterized by the provision of an atmospheric air intake 46 communicating with the inlet channel 43 and being selectively controlled by an air valve 47. Upstream of the air valve 47 is provided atmospheric air silencers 48 causing a pressure drop of approximately 25 kPa.

In Fig. 6B is schematically illustrated an embodiment of an inventive vacuum source 11 control arrangement. In the operation of the waste collection system 1 it is known to continuously monitor the vacuum pressure as well as the air flow in the waste pipes in order to immediately detect any blockage therein. Thus, the inventive control method is characterized by the fact that as an emptying sequence has been started in a first step Sl, said known continuous detection of the vacuum level and the air flow is used in step S2 as an indication of whether or not blockage has been registered somewhere in the pipe system. In particular, this is made by comparing the detected values with predetermined threshold values, based on which it is determined in step S3 whether a blockage has occurred. In case the detected values fall outside the accepted values the atmospheric air intake 46 is opened by opening the atmospheric air valve 47 in step S4. Thereby, a controlled amount of air is introduced.

By the provision of the atmospheric air silencers 48 the introduced air will have a controlled subatmospheric pressure. Simultaneously the speed (RPM) of the fan 40 will be increased and, taken together these measures will secure optimum use of the vacuum fan 40 that has a poor energy efficiency in situations where the air intake is close to zero. It will be realized that in the described arrangement, the controlled subatmospheric pressure will be obtained by producing the correct pressure drop across the silencers 48 being provided upstream of the air valve 47. The speed of the fan 40 will be controlled based on the detected air speed during the emptying sequence, and in a preferred configuration such speed control is performed by means of a variable displacement pump that is mounted on a power take-off of the vehicle 10 engine. As soon as the detected values return to normal the atmospheric air valve 47 is closed again, the speed of the fan is adjusted back to normal and the tank emptying sequence is finished in the normal mode in step S5.

The invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, but it is to be understood that the invention is not to be limited to the disclosed embodiments. Thus the invention is not restricted to configurations where the storage tank auxiliary equipment is a waste agitator, but also covers embodiments where said auxiliary equipment is other present or future means, such as valves. Although the invention has been described and illustrated with specific reference to an illustrated application, the invention is likewise in no way restricted to this specific application. The basic principles of the invention may be applied to most mobile type waste collection systems comprising auxiliary powered equipment, present as well as future, located at the collection points. The invention is therefore intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

PATENT CLAIMS

1. A method of supplying power to auxiliary equipment (20) of a waste collection point (4.1; 4.2; 4.4) in a vacuum operated waste collection system (1), wherein waste storage tanks (2.2; 2.3; 2.4; 3.1; 3.4) at said collection points are emptied at intervals by a vehicle (10) carrying a vacuum source (11) and being selectively connectable to the tanks through waste docking stations (30), characterized by the following steps:

- producing auxiliary electrical power (AEP) onboard the vehicle (10);

- supplying produced auxiliary electrical power from the vehicle to an electrical connecting interface (34) at or near the waste docking station; and

- supplying the auxiliary electrical power from the electric connecting interface to said collection point auxiliary equipment.

2. A method according to claim 1, for use in a system wherein an agitator (20) is provided for rotation in a waste storage tank (2.2; 2.3; 2.4) to assist emptying thereof, characterized by supplying produced auxiliary electrical power (AEP) to a drive motor (21) of the agitator (20).

3. A method according to claims 1 or 2, wherein the vacuum source (11) of the vehicle (10) is releasably connectable to a first pipe connector element (32) of a pipe connecting interface (31) of the docking station (30) through a vehicle-carried pipe (12) having a second pipe connector element (33), characterized by establishing a convenient or alternatively an automatic connection of the auxiliary electrical power (AEP) from the vehicle to the auxiliary equipment (20) by integrating the electrical connecting interface (34) in the docking station (30) or alternatively in the actual pipe connecting interface (31).

4. A method according to claims 2 or 3, by a waste collection system comprising several waste storage tanks (2) that are emptied through allotted docking stations (30) and of which at least one is provided with an agitator (20), characterized by identifying, in connection with each tank emptying procedure, the actual docking station (30) and/or storage tank (2.2; 2.3; 2.4; 3.1; 3.4) being connected to the vehicle (10) for emptying and by starting the production of auxiliary electrical power (AEP) onboard the vehicle only when a waste storage tank 2.2;

2.

3; 2.4; 3.1; 3.

4) being provided with an agitator has been identified for emptying through a respective docking station.

5. A method according to claim 4, characterized by initially storing identification data unique for each waste storage tank (2.2; 2.3; 2.4; 3.1; 3.4) in a non-volatile memory (36) of a tank control box (TCB) associated with each waste storage tank and by reading said unique identification data by each connection of a waste storage tank to the vacuum vehicle (10) for emptying, to thereby identify the connected storage tank.

6. A method according to any of claims 1-5, characterized by grounding the auxiliary electrical power production also through the electrical connecting interface (34).

7. A method according to any of claims 1-6, characterized by producing the auxiliary electrical power (AEP) by means of a hydraulically driven generator (13) onboard the vehicle (10), the hydraulic drive power for the generator being supplied from a propulsion system of the vehicle.

8. A vacuum operated waste collection system (1) in which one or several waste storage tanks (2.2; 2.3; 2.4; 3.1; 3.4) are connected through stationary waste pipe systems (5.1; 5.2; 5.3; 5.4) to a respective waste pipe docking station (30), and in which a vehicle (10) carrying a vacuum source (11) is selectively connectable to the or each docking station through a vehicle carried waste pipe (12), at least one of the tanks (2.2; 2.3; 2.4) having electrically powered auxiliary equipment (20), characterized by:

- an auxiliary electrical power generator (13) mounted on the vehicle (10);

- an electrical power supply line (18.1) on the vehicle and connectable from the generator to; - an electrical connection interface (34) in the vicinity of the pipe docking station (30); and

- a power line (18.2) extended from the electrical connection interface (34) to the storage tank auxiliary equipment (20).

9. A system according to claim 8, wherein an agitator (20) is provided for rotation in a waste storage tank (2.2; 2.3; 2.4) to assist emptying thereof, characterized in that the power line

(18.2) is extended from the electrical connection interface (34) to an electric drive motor (21) for rotating the agitator (20).

10. A system according to claims 8 or 9 wherein the vacuum source (11) of the vehicle (10) is releasably connectable to a first pipe connector element (32) of a pipe connecting interface (31) of the docking station (30) through a vehicle-carried pipe (12) having a second pipe connector element (33), characterized in that the electrical connecting interface (34) is integrated in the docking station (30) or alternatively in the actual pipe connecting interface (31) of the for establishing a convenient or alternatively an automatic connection of the auxiliary electrical power (AEP) from the vehicle to the auxiliary equipment (20).

11. A system according to any of claims 8-10, characterized by storage tank identifying means (35, 36) integrated in a tank control box (TCB) of each waste storage tank (2.2; 2.3; 2.4; 3.1; 3.4) for providing storage tank identification data to a vacuum truck control system (PLC).

12. A system according to claim 11, characterized in that the storage tank identifying means comprise an I/O-device (35) having a non- volatile RAM-memory (36) and by a connection line (37) for connecting each such RAM-memory (36) and said vacuum truck control system (PLC) upon connection of the vacuum truck (10) to a respective docking station (30).

13. A system according to any of claims 8-12, characterized by a grounding line (19) connected to the vehicle (10) generator (13) through the electrical connecting interface (34).

14. A vehicle (10) for use in a vacuum operated waste collection system (1) according to claim 8, characterized in that an auxiliary electric energy producing generator (13) is provided on the vehicle, and by an electrical power supply line (18.1) on the vehicle, for releasable connection from the generator to an electrical connection interface (34) in the vicinity of a waste pipe docking station (30) of the system.