Patent Application
20160031579
The present invention relates generally to processing large bales of material and more particularly relates to removing wrapping material that is used to contain the materials within the bale prior to further processing of the bale material.
In recent years, there has been significant interest in the production of organic chemicals, such as ethanol, from fermentable sugars that are derived from cellulosic biomass. Useful cellulosic biomass includes, for example, corncobs, cornstover (e.g., stalks and leaves), switchgrass, wood chips, and other plant matter.
In order to facilitate the storage and transportation (e.g., to a cellulosic ethanol plant) of cellulosic biomass, the biomass is harvested from the field and is then formed into bales. Common bale configurations include “square bales” (e.g., a bale in the form of a rectangular cube typically measuring about 3′×4′×8′) and “round bales” (e.g., a bale in the form of a right circular cylinder typically measuring about 6′ in diameter and 5′ in length). To provide structural integrity for storage and handling, the bales are often tied with wrapping material such as twine, which is more typical for square bales, or are wrapped with a net wrap or open weave material, which is more typical for round bales.
Once the twine or net wrap is at the cellulosic processing plant, it must be removed from the bale so that the biomass can by fed into the organic chemical production process. Since a typical cellulosic processing plant may process a large number of bales per day, an automated device for the removal of twine and net wrap from bales is desirable. In addition, since the incoming bales to the cellulosic processing plant may consist of both square bales and round bales of varying sizes, it is additionally desirable for a single device to be configured to remove twine and/or net wrap from square bales and/or round bales of varying sizes with minimal manual input.
In cellulosic ethanol processes, materials that are used to tie or wrap individual bales of material (e.g., net wrap and/or twine) must be removed from each bale prior to processing the bale materials in order to avoid complications in various process streams. That is, removing these wrapping materials is necessary to prevent this material from causing mechanical failures or disrupting downstream processes in other ways. Equipment and processes of the present invention are provided to remove the wrapping materials automatically in order to avoid the cumbersome and time-consuming labor required to manually remove these wrapping materials for a commercial scale cellulosic plant.
In one embodiment, the equipment and processes of the invention include using a blade or other sharp cutting member to cut the net wrap, twine, or other material at a location along the length of the bottom of the bale. Such a blade may include a rotating saw or other stationary or rotating cutting device, for example. Such a cutting device can sever the net wrap in a direction that is generally parallel to a longitudinal axis of a round or cylindrical bale, and/or in a direction that is generally parallel to one of the sides of a rectangular bale. The cutting device can either be stationary, with the bale being conveyed past the cutting device during the cutting operation, or the bale can be stationary, with the cutting device traveling along the length of the bale during the cutting operation.
After the wrapping material is cut, multiple rollers can be moved upwardly relative to the deck on which the bale is sitting to engage with the bale at locations that are spaced from the location at which the wrapping material was cut. The multiple rollers can then rotate, such as in opposite directions, in order to pull the wrapping material away from the cut line to move the free ends from under the bale. At this point, the wrapping material will not be constrained by the weight of the bale and is therefore relatively free to move relative to the bale. After this process is complete, a removal device, which may consist of a spear system or a spear and clamp system, can secure the wrapping material and remove it from the outer surface of the bale. The spear system is then rotated on a turret to wind up the wrapping material, and then a material removal system removes the material from the clamp and drops it on a conveyor belt or other location for disposal.
The present invention will be further explained with reference to the appended Figures, wherein like structure is referred to by like numerals throughout the several views, and wherein;
The systems and methods of the invention can generally be used with bales of cellulosic biomass or other material that are harvested and formed into bales, including bale configurations that are cylindrical, bale configurations that are rectangular cubes in shape, and/or bale configurations that have a different shape. To provide structural integrity for storage and handling, the shaped bales are initially at least partially surrounded with wrapping material such as twine or a net wrap or other sheet-like and/or open weave material. Although twine is typically used for wrapping square or rectangular bales, while net wrap is typically used for cylindrical bales, it is possible to use either or both types of materials for bales of any shape or size. When a net wrap or open weave material is used to wrap a bale, it typically extends along all or most of the length of the bale, and surrounds the outer periphery of the bale. When a twine or other elongated material is used to wrap a bale, it is typical for the bales to have 4-6 strands or wraps of twine surrounding the outer periphery of the bale and spaced from each other along the length of the bale, although it is possible to have more or less twine strands or wraps. The ends of the bales may or may not be covered or partially covered with wrapping material. It is noted that the material removal systems of the invention can be used with other wrapping materials or combinations of wrapping materials, and can be used with bales having shapes that are not cylinders or rectangular cubes.
Referring now to the Figures, wherein the components are labeled with like numerals throughout the several Figures, and initially to
The process of removing wrapping material begins by placing a wrapped bale onto the conveyor system 20. The conveyor system 20 can be positioned so that it starts at the cutting station 12 to allow for a bale to be loaded directly into the cutting station 12 (e.g., by a forklift operator) or may start in a location prior to the cutting station 12 such that a bale is conveyed into the cutting station 12 from a loading dock or other area. In either case, the cutting station 12 optionally includes positioning members 30 spaced from each other on opposite sides of the cutting station width. These members 30 include rails 32 that extend from support members 34. The rails 32 can be angled outwardly away from the center of the cutting station 12 at their proximal ends so that they can act as guide rails that keep a bale centered as it enters the cutting station 12. The positioning members 30 are generally positioned at a location that is above the conveyor system 20 and below the top surface of the bales that are being processed so that they can provide the desired centering function. As shown, the positioning members 30 can optionally be adjustable toward and away from the center of the cutting station by moving them laterally along the support members 34. Any number of mechanisms can be used to adjust and secure the positioning members 30 in their desired location, including manual adjustment and securing devices, or automated devices that are controlled by feedback received from sensors, for example.
The cutting station 12 can be provided with one or more devices and/or mechanisms for cutting the material that is wrapping the bale without causing substantial damage to the bale material itself. That is, the blade or other device is positioned relative to the cutting device so that it will reliably and repeatedly sever wrapping material while minimally penetrating the bale material adjacent to the cut area. In an embodiment of the cutting station 12, a rotating saw blade 40 is positioned on a support frame, wherein the saw blade is a circular disc with multiple teeth around its circumference, such as a metal saw blade or a disc made of an abrasive or other material that is sufficiently sharp that it can cut relatively easily through the wrapping material. In another embodiment, the saw mount is attached to the bottom of the conveyor to support the saw, such as by a direct attachment to the bottom surface of one or more extending members of a conveyor guard or other conveyor structure. With such an arrangement, no separate support stands or structures are required to operatively support the saw blade or other cutting device.
In operation, the bale enters the cutting station 12, and then it passes over a cutting mechanism that can include one of the configurations discussed above, for example. The cutting station 12 may further include a blade guard that covers a portion of the exposed blade, and/or may include an auxiliary guard positioned to prevent or minimize material generated by the cutting operations from building up on the saw and/or its associated shaft.
The speed at which any saw blade of the cutting station 12 rotates may be controlled by a conventional motor and control system that provides a required rotation speed to correspond with the particular material that is being cut. Further, the speed at which the bale is moving along the conveyor can be coordinated with the speed of rotation of the saw blade in order to optimize the cutting performance of the saw blade.
One or more sensors can be used to determine and monitor the size and location of the bale as it moves into the cutting station 12. In any of the mounting systems described herein, the saw blade extends upwardly through an opening in the deck of the conveyor system 20 and is positioned vertically so that it can cut through any wrapping materials of the bale, but is not positioned so high that it causes excessive damage to the bale itself. In a variation of this process that is within the scope of this invention, the bale can instead be moved into a location within the cutting station prior to any cutting being performed, and the bale can remain stationary while a cutting mechanism is moved along the bale length to cut the wrapping material. In either case, once the wrapping material has been cut, the bale is ready to be moved to the next station of the system 10.
The conveyor system 20 is then reactivated to move the bale toward the material pulling station 14. Again, one or more proximity sensors, such as sensor 36 illustrated in
The rollers can have a variety of different configurations, but in one exemplary embodiment, the rollers are 8 inches in diameter and are approximately 7 feet long. In order to provide a desired level of friction between the wrapping material and the rollers, the outer surface of the rollers can include a rubberized material or other material against which the wrapping material does not slip. After the material pulling operation is complete, the rollers can retract below the surface of the conveyor so that they do not interfere with continued movement of the bale from the station 14. At this point, the cut ends of the wrapping material will generally be loose so that the wrapping material drapes or hangs freely over the top of the bale, and the bale is therefore ready to be moved via the conveyor to the next station of the system 10. It is noted that if the wrapping material is twine, the rolling operation to free the ends of the twine from under the roller may optionally be used, as desired, while the rolling operation would more typically be used for net wrap or other wrapping materials that have more surface area than twine.
The area immediately adjacent to and beneath the rollers of station 14 may include one or more angled plates that are used for collecting material that comes loose from the bales during the process of conveying the bale and loosening the wrapping material from its outer surface. The angled plates can direct the loose material downwardly and onto an optional waste conveyor that can convey the material away from the rollers and into a collection area so that the loose material can be processed along with the other materials provided by the bale.
After the wrapping material ends are free from under the bale, the conveyor system 20 is then reactivated to move the bale into the material wind-up or material removal station 16, which is the station at which the wrapping material is removed from the bale. Again, one or more proximity sensors can be used to sense the position of the bale so that it can be stopped in a desired location within the material removal station 16. Additional proximity sensors (e.g., laser sensors) can be used in this station and/or in one or more of the previous stations to accurately determine the location of the top surface of the bale, which information is transmitted to a controller that can adjust the locations of various components within the station 16.
Station 16 includes a material wind-up system 60 that has at least two spears 62, 64 that extend longitudinally from a base plate 66. The material wind-up system 60 is vertically moveable to position one of the spears 62, 64 at least slightly below the wrapping material in a vertical direction (i.e., between inner surface of the wrapping material and the outer surface of the bale itself). In an embodiment of the invention, the material wind-up system 60, or at least a portion thereof, is vertically positionable via a cylinder 68 (e.g. a hydraulic cylinder) that is located within a lift tower 80, such as is also illustrated in
Lift tower 80 includes a stationary frame member 82 that is configured as an inverted U-shaped structure that extends upwardly from the lower support structure of the material stripping station 18. The frame member 82 can include multiple support pieces that are connected throughout its structure to provide a desired amount of stability. Tower 80 further includes a moveable frame member 84 that is vertically positionable relative to the stationary frame member 82. Frame member 84 includes two side structures 86, 88 spaced from each other and a support structure 90 extending between them. The side structures 86, 88 each include two vertical rails 87, 89, respectively, which are configured for engagement with rollers, as is described below. The cylinder 68 extends downwardly from the support structure 90 and can be positioned generally at the center of gravity of the lift tower 80, for example. Cylinder 68 includes a shaft that is used to raise and lower the moveable frame member 84 and control the height of the corresponding material wind-up system 60.
Lift tower 80 further includes a roller frame 100 that surrounds both the stationary frame member 82 and the moveable frame member 84. Roller frame 100 is mounted so that it is stationary relative to the lower support structure of the material stripping station 18. Roller frame 100 includes side members 102. 104 that are spaced from each other in the same direction that the side structures 86, 88 of the frame member 84 are spaced from each other. Each of the side members 102, 104 extends in a generally horizontal direction and includes rollers 106 adjacent to each of their ends. Rollers 106 are mounted in the inner area of the roller frame 100 for engagement with the vertical rails 87, 89 of the vertical rails 86, 88. During movement of the moveable frame member 84 relative to the stationary frame member 82, each of the rollers 106 will ride vertically along one of the vertical rails 87, 89, and are therefore made of materials that will cooperate with the material from which the rails are made. Bearings can hold the rollers 106 against the rails 87, 89 and the bearing shafts can be adjusted to tension the rollers against the rails 87, 89 to compensate for wear, if desired. The use of a single cylinder 68 can help to compensate for any alignment issues that otherwise may occur when raising and lowering the moveable frame member 84, although it is understood that more than one cylinder can be used for this purpose.
Once the bale has been moved into the station 16 by a sufficient distance that one of the spears 62, 64 is fully engaged along at least a portion of its length with the wrapping material, the conveyor system 20 can again be stopped so that the bale is stationary. At this point, the other of the two spears 62, 64 (i.e., the spear that is not positioned under the wrapping material) can optionally be moved to clamp or grasp the wrapping material between the two spears, although it is also contemplated that the spears 62, 64 do not move relative to each other. Whether or not a clamping motion is activated, the material wind-up system 60 can then be moved upwardly at least slightly relative to the outer surface of the bale until a desired amount of tension is placed on the wrapping material. The spears 62, 64 can then be rotated or spun via their support plate 66 until all or most of the wrapping material is wrapped around the spears 62, 64. Once the wrapping material is wrapped around the spears in this way, the bale can be moved toward the end of the system 10 by reactivating the conveyor until the unwrapped bale reaches the end of the conveyor is available for use in another manufacturing process.
At this point, the wrapping material will be entirely removed from the bale and wrapped around the spears 62, 64, and the material wind-up system 60 can be rotated from a position to where the spears 62, 64 are extending generally in the direction of travel of the bales via the conveyor to a position that is at an angle from this direction of travel. For example, as is illustrated in
Referring additionally to
In one embodiment, the fin 80 retracts by rotation about a pivot point, although it is understood that the fin 80 can instead be vertically retractable into the slot 74 by sliding it upward using a different mechanism that provides for extension and retraction of the fin 80. In its extended position, the fin 80 is positionable between the spears 62, 64 for removal of the wrapping material from the spears. Thus, in order for the material removal system 70 to provide such a function, the spears 62, 64 will be positioned so that they are both generally parallel to each other in a horizontal plane and so that fin 80 can extend downwardly between them.
The fin 80 has a length that is allows it to extend by a desired distance between the spears 62, 64 when in its extended position. The fin 80 can have a tapered shape, as shown, or can be relatively blunt and/or differently shaped. The fin 80 is rigid enough that it does not deform substantially during the process of removing wrapping material from the spears. It is noted that the vertical aspect of the fin 80 will allow gravity to facilitate the movement of the wrapping material from the material wind-up system 60. It is further noted that a new bale of material can simultaneously be moving into and/or through the other stations of the system 10 while the material is being removed from the spears 62, 64 using the material removal system 70.
An exemplary starting position of the fin 80 and its corresponding carriage 76 is illustrated in
The present invention has now been described with reference to several embodiments thereof. The entire disclosure of any patent or patent application identified herein is hereby incorporated by reference. The foregoing detailed description and examples have been given for clarity of understanding only. No unnecessary limitations are to be understood therefrom. It will be apparent to those skilled in the art that many changes can be made in the embodiments described without departing from the scope of the invention. Thus, the scope of the present invention should not be limited to the structures described herein, but only by the structures described by the language of the claims and the equivalents of those structures.
