Patent Publication Number: US-6336306-B1

Title: Round-bale press and a method of compressing refuse

Description:
TECHNICAL FIELD 
     The present invention relates to a round-bale press and a method of compressing refuse into round bales. 
     To supply refuse to thermal processing to obtain heat or power, it is practical to compress the refuse into round bales in round-bale presses for the purpose of transporting and storing the refuse; such round bales are then kept dimensionally stable by means of an outer film which also protects them from the effects of weather. 
     PRIOR ART 
     A round-bale press for the production of refuse bales is known for example from DE 39 41 727. Refuse is introduced into a compressing chamber of a round-bale press via a feed hopper. The refuse is compacted inside this compressing chamber by means of wrapping rollers driven at the peripheral side and positioned into a predefined round-bale form. The round bale is then pre-secured by means of a net web. Part of the round-bale press&#39;s rear housing wall can be upwardly pivoted for removal of the refuse bale. The refuse bale is then transported over a roller conveyor to a wrapping table where a film is wrapped around this bale in such a way as to pack it in a dimensionally stable, weatherproof and storable manner. The plurality of driven wrapping rollers causes the energy consumption of such a round-bale press to be relatively high during compaction of the refuse bale. Upwardly pivoting part of the housing wall entails considerable construction space for the round-bale press. 
     A round-bale press which uses a driven link conveyor for compacting and shaping a round bale is known from WO 95/00324. The link conveyor is driven by disk-like side walls which simultaneously form the lateral limit of the compressing chamber. The refuse is pre-compacted and introduced into the compressing chamber via a second link conveyor. After the refuse has been compacted inside the compressing chamber and has been formed into a round bale, the round bale is pre-secured using a net web. To discharge the refuse bale from the compressing chamber, a plurality of endless belt segments of the link conveyor guidance are pivoted outwards. The refuse bale, which is still held between the two side walls, is then lifted, together with these side walls, out of the opened compressing chamber via lever arms. As soon as the side walls release the refuse bale, it can be conveyed to the wrapping table via an additional conveyor belt. This round-bale press version also needs considerable construction space above the compressing chamber in order to remove the refuse bale. Additional conveyance means for moving the pre-secured refuse bale from the compressing chamber to the wrapping table increase the construction costs of such a refuse packing device and consume additional energy. 
     DEPICTION OF THE INVENTION 
     A technical problem underlying the invention is to provide a round-bale press for packing refuse, the constructional outlay of which is simplified and which needs less construction space. 
     This technical problem is solved by a round-bale press for compressing refuse into round bales. Such a round-bale press comprises: a compressing chamber into which the refuse can be introduced, a driven endless belt that limits the compressing chamber at the peripheral side and rotates the refuse contained therein, and two side walls formed as circular disks and which limit the compressing chamber at the end face, whereby an endless belt segment of the endless belt can be pivoted by at least one drive element out of a refuse compressing position into a discharge position in which the obtained round bale can be removed on the pivoted endless belt segment. 
     The invention is also based upon the technical problem of providing a round-bale press that can be used to simplify removal of the pre-secured refuse bales from the compressing chamber. 
     This problem is solved by a round-bale press comprising: a compressing chamber into which the refuse can be introduced, a driven endless belt that limits the compressing chamber at the peripheral side and rotates the refuse contained therein, and two side walls which limit the compressing chamber at the end face, whereby an endless belt segment of the endless belt can be pivoted out of a refuse compressing position into a discharge position in which the obtained round bale can be removed on the pivoted endless belt segment. 
     The invention is also based upon the technical problem of designing a round-bale press for compressing refuse into round bales that ensures long-lasting and reliable operation. 
     This technical problem is solved by a round-bale press for compressing refuse into round bales comprising: a compressing chamber into which the refuse can be introduced, a driven endless belt which limits the compressing chamber at the peripheral side and rotates the refuse contained therein, and two side walls which limit the compressing chamber at the end face, whereby an endless belt segment of the endless belt can be pivoted out of a refuse compressing position into a discharge position in which the obtained round bale can be removed on the pivoted endless belt segment, with the endless belt being a link conveyor whose links are made of aluminum or an aluminum alloy. 
     Finally, the invention is based on the problem of providing a simple and inexpensive method of compressing and discharging round bales of refuse. This problem is solved by a method of compressing and discharging refuse in round bales; in this method refuse is introduced through a feed aperture into a compressing chamber defined by an endless belt—guided by one of a plurality of deflection rollers—and two side walls, the refuse is rotated inside the compressing chamber and refuse continues to be introduced until a refuse bale of a predetermined size is produced, a securing means, such as a net web, is then wrapped, at the peripheral side, around this refuse bale produced in the above manner, a pivotably supported endless belt segment of the endless belt is pivoted out of the refuse compressing position into a position for discharging the round bale, thus creating a transport path for the compressed round bale to a wrapping table downstream of the compressing chamber, and the refuse bale that is secured at the peripheral side is removed from the compressing chamber by the endless belt via the pivoted endless belt segment as a result of letting the endless belt run. 
     The invention is based upon the idea that the endless belt, which together with two end-face side walls defines the compressing chamber for the purpose of receiving the refuse and compressing it into round bales, is also used for the first time as a discharge means. A compressed round bale can be discharged without additional constructional outlay as a result of an endless belt segment which is pivoted out of a refuse compressing position into a discharge position. Until now, separate devices had been necessary for this purpose. A conveyor means for transporting the pre-secured refuse bales to the wrapping table can be replaced by the pivotably supported endless belt segment of the compressing chamber, with the endless belt assuming the function of a conveyor belt. The pivoted endless belt segment preferably bridges over the space necessary for the wrapping device between the round-bale press and the wrapping table on which a film web is then completely wrapped around the pre-secured refuse bale in order to protect it from the effects of weather and to keep it dimensionally rigid. In this way, the space required by the round-bale press above the compressing chamber is not only reduced, but the space needed between the compressing chamber and the wrapping table is also decreased. 
     Further preferred embodiments are characterized by the dependent claims. 
     The endless belt is preferably guided via at least four deflection rollers, whereby in order to discharge the round bale from the compressing chamber, an endless belt segment to which at least one of these deflection rollers is attached can be pivoted such that the endless belt segment preferably pivots away around the axis of one of the deflection rollers. The use of fewer deflection rollers considerably reduces the endless belt/deflection roller system&#39;s design-related resistance. 
     According to a preferred embodiment, at least one of the deflection rollers of the endless belt is designed as a drive roller. This ensures that the endless belt is driven irrespective of whether it engages with the optionally disk-like side walls. Another of the deflection rollers is preferably designed as a tension roller that tensions the endless belt, with the deflection roller arrangement according to the invention ensuring that this tension is disposed on the slack side. The arrangement of a tension roller on the slack side of the endless belt simplifies the introduction of a defined pre-tension into the endless belt. 
     According to another preferred embodiment, another roller that deflects the endless belt is arranged on the pivotably supported endless belt segment; this roller also contributes toward compacting the refuse inside the compressing chamber. This additional compaction roller improves the endless belt&#39;s guidance and compaction characteristics. 
     A means for pre-securing the compacted round bale is preferably provided at or within the compressing chamber. This may for example be a means of wrapping yarn or a net web around the round bale. 
     The pivotably supported endless belt segment of the compressing chamber is preferably moved via a drive element. Hydraulic or pneumatic piston drives have particularly proved beneficial for this purpose. The use of a rack in conjunction with an electric motor that drives a pinion is also possible. 
     According to a preferred embodiment, a defined aperture through which refuse can be introduced into the compressing chamber is obtained between two deflection rollers once the pivotable endless belt segment has been folded up into a compaction position. A special conveyor device which pre-compacts and transports the refuse to be fed into the compressing chamber is not absolutely necessary, but can be provided if required. 
     According to another preferred embodiment, ribs which point into the compressing chamber are attached to the endless belt. The width of the endless belt is preferably larger than the distance between the two side walls which are ideally formed as circular plates. The endless belt passes at least in part around the side walls. The compressing chamber side walls are preferably rotatably supported, causing them to rotate together with the refuse, driven by the endless belt. In this instance, the ribs are arranged only in an endless belt section located between the two disk-like side walls. These ribs help the refuse to be rotated inside the compressing chamber, thus compressing it into a refuse bale of a predetermined size. These ribs also improve the endless belt&#39;s conveyance characteristics when discharging the refuse bale from the compressing chamber. 
     The endless belt is preferably a link conveyor. The link conveyor&#39;s individual links are joined together in an overlapping manner by means of bars. The bars are received by bores in the individual links, with the bores each being designed as clearance fit on the one side, whereas they are designed as transition fit on the other side of the links. In this way, it is ensured that the link conveyor&#39;s individual links bend at defined sites during deflection via the deflection rollers. To reduce the weight, it is advantageous to produce the link conveyor&#39;s links from aluminum or an aluminum alloy. Apart from its low specific weight, this material simultaneously exhibits good resistance to corrosion. Depending on the refuse material to be compressed, the use of various plastics or other metals is also suitable for the link conveyor&#39;s links. 
     According to a final embodiment, the device for packing refuse also comprises a spray means which can on the one hand clean the endless belt, but which can also lubricate the endless belt. Lubrication of the link conveyor&#39;s joints is necessary particularly if dry refuse is used. Another advantage of such a spray means is that dust from dry refuse can largely be prevented from whirling up when the link conveyor is sprayed e.g. with an emulsion of oil and water. 
    
    
     SHORT DESCRIPTION OF THE DRAWINGS 
     The invention will now be described purely by way of example on the basis of the attached drawings. 
     FIG. 1 shows a round-bale press according to the invention comprising a pivotable endless belt segment folded up into a refuse compressing position; 
     FIG. 2 shows a side view of a round-bale press according to the invention comprising a pivotable endless belt segment folded down into a position for discharging round bales; 
     FIG. 3 shows a schematic arrangement of deflection rollers and endless belt according to the present invention; 
     FIG. 4 shows a perspective representation of a round-bale press according to the invention in FIG. 1; 
     FIG. 5 shows links according to the invention which are combined into a link conveyor; and 
     FIG. 6 shows a side view of a round-bale press and a wrapping table according to the invention. 
    
    
     DESCRIPTION OF THE INVENTION&#39;S EXEMPLARY EMBODIMENTS 
     A round-bale press according to the invention depicted in FIG. 1 comprises an endless belt  12  guided around a plurality of deflection rollers  18 ,  20 ,  22 ,  26  and  30  and via two disk-like side walls  14  and  16 . This defines a compressing chamber  10  into which refuse to be compacted can be fed via a feed aperture  34 . An endless belt segment  24  is pivotably supported around the axis of one of the deflection rollers  22 , thus enabling the endless belt segment  24  with deflection rollers  26  and  30  attached thereto to be pivoted out of the largely vertical position shown in FIG.  1 —and suitable for compacting refuse into round bales—into a largely horizontal position shown in FIG.  2  and suitable for discharging the round bale from the compressing chamber and conveying the round bale to a wrapping table. The endless belt segment  24  is moved via a hydraulic or pneumatic piston drive  32  secured both to the endless belt segment  24  and to the round-bale press frame. 
     The endless belt  12  is driven via a deflection roller  18  designed as a drive roller. Another deflection roller  20  is designed as a tension roller, with the tension roller  20  being disposed on the slack side of the endless belt  12 . 
     FIG. 3 also shows a means  28  for pre-securing the compressed round bale. This may for example be a means for unwinding yarns or net webs  48 . Pre-securing is intended to keep the compacted round bale dimensionally stable in the peripheral direction while it is being conveyed out of the round-bale press to the wrapping table  100 —shown in FIG. 6 where a film web is wrapped completely around the bale. This film web permanently secures the round bale in its shape, thereby preventing loss of refuse during the round bale&#39;s transportation or storage, or damage to the refuse bale as a result of the effects of weather. 
     The pivotability—shown in FIG.  3 —of the endless belt segment  24  with deflection rollers  26  and  30  attached thereto guarantees that the compacted round bale is directly discharged from the compressing chamber  10  via the endless belt  12  acting as a conveyor belt  50  and rotating over the endless belt segment  24  that is pivoted into a largely horizontal position. The wrapping table is arranged such that the distance between the wrapping table and the round-bale press is bridged exactly by the endless belt segment  24  folded down to a transport path  50 . In this way, the compacted and pre-secured round bale can be conveyed as a result of letting the endless belt  12  run, without having to lift the bale out of the compressing chamber  10  via a grab arm. 
     In FIG. 5, the endless belt  12  according to an exemplary embodiment is designed as a link conveyor. The individual links  38  of the link conveyor  12  are joined together via bars  40 . At one end, the links  38  comprise bores  42  with a clearance fit; at their other end, the links  38  comprise bores  44  with a transition fit. This ensures that the connection of the individual links  38  by the bars  40  forms a defined hinge element. 
     The links  38  of the link conveyor  12  comprise ribs  36  on one side, as is evident from FIG.  5 . These ribs  36  are arranged such as to be located on a section of the link conveyor  12  situated between the two disk-like side walls  14  and  16 , and point into the compressing chamber  10 . 
     To clean and lubricate the link conveyor  12  there is provided a spray means  46  shown in FIG.  1  and which sprays water or an emulsion of oil and water onto the individual links  38  of the link conveyor  12  at a high pressure. The use of this spray means  46  is particularly necessary if dry refuse is used in the round-bale press in order to ensure the necessary lubrication of the individual links  38  of the link conveyor  12 .