EP2142449B1

EP2142449B1 - Vacuum operated waste collection system

Info

Publication number: EP2142449B1
Application number: EP07748052.3A
Authority: EP
Inventors: Rune Hammar; Mattias Pihl
Original assignee: Envac AB
Current assignee: Envac AB
Priority date: 2007-04-20
Filing date: 2007-04-20
Publication date: 2017-01-04
Anticipated expiration: 2027-04-20
Also published as: WO2008130289A8; DK2142449T3; EP2142449A4; ES2621178T3; EP2142449A1; WO2008130289A1

Description

TECHNICAL FIELD

The present invention relates to a vacuum operated waste collection system according to the preamble of claim 1, and to a method of supplying power according to claim 6.

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.
WO-A-2006/059896 discloses a vehicle that comprises a power source for providing power supply to an external, separate installation to be energized. An external connection is further provided, which is connected to the power source and which can be connected to the external installation for selective energizing thereof with the power supply.
WO-A-2006/135296 discloses a vacuum operated waste collection system according to the preamble of claim 1.

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 vacuum operated waste collection system, as defined in the appended claims.
In particular, it is an object of the invention to provide an improved vacuum operated waste collection system.
In particular, it is another object of the invention to provide an improved method of supplying power to the electric drive motor of the electrically powered agitator in at least one of the waste storage tanks of a waste collection point in the vacuum operated waste collection system.
Specifically the invention provides a vacuum operated waste collection system wherein waste storage tanks of a waste collection point are connected through a stationary waste pipe system to a waste pipe docking station, and in which a vehicle carrying a vacuum source is connectable to the docking station through a vehicle carried waste pipe, at least one of the tanks has an electrically powered agitator provided therein to assist emptying of the waste storage tank, whereby the vacuum source of the vehicle is releasably connectable to a first pipe connector element of a pipe connecting interface of the waste pipe docking station through the vehicle-carried pipe having a second pipe connector element. According to the invention an auxiliary electrical power generator is provided on the vehicle, an electrical power supply line is provided on the vehicle and is connectable from the generator to an electrical connection interface being integrated in the waste pipe docking station or in the pipe connecting interface of the docking station and electrical power connection lines are laid down alongside the stationary waste pipe system, extending from the electrical connection interface to an electric drive motor for rotating the electrically powered agitator of said at least one of the waste storage tanks having such an electrically powered agitator.
In another aspect the invention provides a method of supplying power to the electric drive motor of the electrically powered agitator in at least one of the waste storage of a waste collection point in the vacuum operated waste collection system of the invention, whereby auxiliary electrical power is produced by means of the auxiliary electrical power generator onboard the vehicle of the system, an electrical connection is established through the electrical connecting interface of the system and produced auxiliary electrical power is supplied from the auxiliary electrical power generator to the electric drive motor.
One advantage of the suggested system and method 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 a further embodiment of the invention 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 a power supply system;
Fig. 4 is a very schematical illustration of the general outline of a connecting interface;
Fig. 5 is a schematical illustration of a tank identification arrangement;
Fig. 6A is a detail view of a vacuum source for a vehicle; and
Fig. 6B is a schematical illustration of a vacuum fan control arrangement.

DETAILED DESCRIPTION

The invention will now be explained with reference to an exemplifying embodiment of the system and method, illustrated particularly in drawing figures 3-5. The illustrated, exemplifying embodiment relates to an application of the solution to an exemplary waste collection system of the mobile type that is schematically illustrated in drawing figures 1-2.
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 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 vehicle 10 for emptying. With the vehicle 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 WO-A-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, a system integrated electric power supply for auxiliary equipment employed at the collection points is provided. In the embodiment illustrated in Fig. 3 said auxiliary equipment is an agitator, as represented by its drive motor 21, for a storage tank 2.2, 2.3, 2.4 of a collection point 4.2; 4.1 in the waste collection system 1. The auxiliary electrical power produced onboard the vehicle 10 is used for emptying the system storage tanks at regular intervals. 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.
As the vacuum source of the 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 4.1; 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. In the 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. A practical or convenient 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. Or the electrical connection interface 34 and the pipe connecting interface 31 is 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, 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 kW, 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. The electrical connection interface 34 is physically or functionally integrated in the actual pipe connecting interface 31 in the waste pipe 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 storage tank identification arrangement, 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 WO-A-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 vehicle 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 vehicle 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 vehicle 10 is actually connected to a waste tank requiring auxiliary electric power.
In Fig. 6A is illustrated an exemplary vacuum fan 40 for use as the vacuum source 11 in the vehicle 10.
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 comprises an atmospheric air intake 46 communicating with the inlet channel 43 and is 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 a 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, when an emptying sequence has been started in a first step S1, 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 such speed control may be 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. The invention is therefore intended to cover various modifications included within the scope of the appended claims.

Claims

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) of a waste collection point (4.1; 4.2; 4.4) are connected through a stationary waste pipe system (5.1; 5.2; 5.3; 5.4) to a waste pipe docking station (30), and in which a vehicle (10) carrying a vacuum source (11) is selectively connectable to the waste pipe docking station (30) through a vehicle carried waste pipe (12), at least one of the waste storage tanks (2.2; 2.3; 2.4) has an electrically powered agitator (20) provided therein to assist emptying of the waste storage tank (2,2;2.3;2.4;3.1;3.4) whereby 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 waste pipe docking station (30) through the vehicle-carried pipe (12) having a second pipe connector element (33), characterized by an auxiliary electrical power generator (13) on the vehicle (10), an electrical power supply line (18.1) on the vehicle (10) and connectable from the auxiliary electrical power generator (13) to an electrical connection interface (34) being integrated in the waste pipe docking station (30) or in the pipe connecting interface (31) of the waste pipe docking station (30), and by electrical power connection lines (18.2) laid down alongside the stationary waste pipe system (5.1; 5.2; 5.3; 5.4), extending from the electrical connection interface (34) to an electric drive motor (21) for rotating the electrically powered agitator (20) of said at least one of the waste storage tanks (2.2; 2.3; 2.4) having such an electrically powered agitator (20).
The vacuum operated waste collection system (1) according to claim 1, characterized by waste storage tank identifying means (35, 36) integrated in a tank control box of each waste storage tank (2.2; 2.3; 2.4; 3.1; 3.4) for providing waste storage tank identification data to a vacuum truck control system of the vehicle (10).
The vacuum operated waste collection system (1) according to claim 2, characterized in that the waste 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 non-volatile RAM-memory (36) and said vacuum truck control system upon connection of the vehicle (10) to the waste pipe docking station (30).
The vacuum operated waste collection system (1) according to any of claims 1-3, characterized in that the auxiliary electrical power generator (13) is hydraulically driven, the hydraulic drive power being supplied from a propulsion system of the vehicle (10).
The vacuum operated waste collection system (1) according to any of claims 1-3, characterized in that the auxiliary electrical power generator (13) is grounded by means of a grounding line (19) connected to the vehicle (10) through the electrical connecting interface (34).
A method of supplying power to the electric drive motor (21) of the electrically powered agitator (20) in at least one of the waste storage tanks (2.2; 2.3; 2.4) of a waste collection point (4.1; 4.2; 4.4) in the vacuum operated waste collection system (1) according to any of the claims 1-5, comprising the following steps:
- producing auxiliary electrical power (AEP) by means of the auxiliary electrical power generator (13) on-board the vehicle (10);

- establishing an electrical connection through the electrical connecting interface (34); and

- supplying produced auxiliary electrical power from the auxiliary electrical power generator (13) to the electric drive motor (21).
The method according to claim 6, characterized by identifying, in connection with each tank emptying procedure, the waste pipe docking station (30) and/or waste 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 on-board the vehicle (10) only when a waste storage tank (2.2; 2.3; 2.4; 3.1; 3.4) being provided with an electrically powered agitator (20) has been identified for emptying through a respective waste pipe docking station (30).
The method according to claim 7, 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 RAM-memory (36) of a tank control box associated with each waste storage tank (2.2; 2.3; 2.4; 3.1; 3.4) and by reading said unique identification data by each connection of a waste storage tank (2.2; 2.3; 2.4; 3.1; 3.4) to the vehicle (10) for emptying, to thereby identify the connected waste storage tank (2.2; 2.3; 2.4; 3.1; 3.4).
The method according to any of claims 6-8, characterized by grounding the auxiliary electrical power production through the electrical connecting interface (34).
The method according to any of claims 6-9, characterized by producing the auxiliary electrical power by means of a hydraulically driven generator (13) on-board the vehicle (10), the hydraulic drive power for the generator (13) being supplied from a propulsion system of the vehicle (10).