Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – Waste paper or textile waste
Reexamination Certificate
1999-10-14
2001-07-17
Nguyen, Dean T. (Department: 1731)
Paper making and fiber liberation
Processes of chemical liberation, recovery or purification...
Waste paper or textile waste
C162S055000, C209S705000, C209S632000, C241S101010, C241S186400, C241S280000
Reexamination Certificate
active
06261410
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. §119 of German Patent Application No. 198 47 532.2, filed on Oct. 16, 1998, the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for separating compressed material containing paper fibers including paper or paperboard webs.
2. Discussion of Background Information
The manufacture of paper or paperboard frequently uses waste paper which is supplied in the form of bales. Even native pulp is often initially formed into bales after production. Such bales are generally produced by compressing the material and then tying it with wires or bands, thus, providing a compact form that is relatively easy to transport. For use as new raw material, it is necessary to break up these compressed bales into individual paper webs or pieces again in order to be able to perform the subsequent procedures for processing the material. Even after the binding wires or bands have been removed from compressed bales, in most cases they stay in one piece or in such large pieces that feeding them into equipment, such as a water-operated pulp dissolver, can cause problems. Moreover, in many cases the material delivered is contaminated with foreign materials, e.g., plastic film, that have been compressed into the bale. These plastic films often adhere to the paper material, which poses an obstacle to their early removal.
German Application No. DE 34 39 098 A1 describes a process in which, in a relatively resource-intensive fashion, bales of recycled waste paper are separated, broken up, and cleaned and brought into suspension by subsequently adding water to them in a pulper. Although this process can be viewed as a suitable step for starting the processing of recycled paper, it has not been generally adopted on account of its high cost.
Machines are already known with which a process of the type generally described above could be performed. These are sturdy coarse chopping or grinding machines, e.g., shredders, that are specifically intended to pre-grind coarse material, e.g., scrap or rocky material, so that it can subsequently further processed or sorted. The use of a shredder in a process of the type generally described above would require a very large machine with a correspondingly high price on account of the size of the bales or bale fragments. Thus, the disadvantages of such a device would include not only its cost and the space required, but also high power consumption. In addition, the operation of such a machine is very harsh and causes a considerable amount of noise.
Another possibility would be the use of a screw extruder or another type of open screw conveyor with at least two conveyor screws. However, machines of this type are also very expensive and have a high power consumption. Moreover, it is necessary to take into account that these machines can also at least partially crush the compressed pulp rather than separate it.
SUMMARY OF THE INVENTION
The present invention provides a process with which it is possible to separate compressed material containing paper fibers at least to such an extent that processing in a pulp dissolver is possible and appropriate. In this manner, cost is kept as low as possible.
Therefore, the present invention relates to a process that includes transporting a material, over at least three hammer rollers arranged essentially in a plane, in a direction essentially parallel to the plane and transverse to the axes of the rollers. The hammer rollers include rotatable hammers adapted to penetrate the material and separate it. Further, the hammer rollers are arranged to form gaps between the hammer rollers so that broken up fine material falls through the gaps to be separated from the material which is broken up to a lesser extent or not at all.
The apparatus of the instant invention includes a machine frame having a number of driven rotors arranged next to one another in the machine frame. The axes of the rotors are arranged to lie at least partially in one plane and free gaps are located between the rotors. A delivery unit is provided to deliver a material to be processed into a region above the rotors, and a removal unit is provided to remove the processed material from a region below the rotors. The rotors include hammer rollers having shafts with hammers attached thereto, and at least some adjacent hammer rollers are adapted to be rotatably drivable in a same rotational direction.
When the process according to the invention is used, the material may be continually separated as it passes over rotating hammer rollers to break up the bond created by the compression. In other words, the bales and pieces of bales are broken up. During the process, the material can be pressed against the rotating hammers because of its weight, but can also escape upward or to the side upon occasion. Through this form of mechanical processing, forces may be transmitted that are especially well suited to breaking up the material into a fine material. This is because these forces are sufficient to break the bond of the compressed material, but are not great enough that unnecessary power consumption is required and/or that there is a risk of damage to the devices used during the process, especially from foreign bodies contained in the material.
A further advantage is that the process can be adjusted very well to the particular application at hand. After all, the form in which the material is delivered can be expected to vary considerably. In addition to great variation in the bale size and compression force, variation also results from differences in the material itself It is easy to see that heavy cardboard items will behave differently on the baling press than scraps of office waste (e.g., printed matter, files). Further differences can include differences in moisture content and different degrees of contamination. The process of the present invention can be adapted to particular applications through the apparatus, e.g., by appropriately selecting the number of hammer rollers and/or the shape of the hammers used. But even when an existing apparatus is used that is suitable for the process, one can react with flexibility to different requirements through such measures as tilting the apparatus and varying the hammer roller speed.
Accordingly, the instant invention is directed to a process for separating compressed material containing paper fibers in an apparatus that includes at least three hammer rollers arranged essentially in a same plane and each hammer roller includes rotatable hammers. The process includes rotating the rotatable hammers, transporting the material over the at least three hammer rollers in a transport direction essentially parallel to the plane and transverse to the axes of the rollers, breaking up the material into fine material and non-fine material, and separating the fine material from the non-fine material by allowing the fine material to pass through gaps formed between the hammer rollers.
In accordance with another feature of the instant invention, the non-file material may include coarse material, and the process can further include carrying away the coarse material.
In accordance with still another feature of the invention, at the start of the breaking up and separating, the material can include one of bales or large pieces of bales at least some of which have a weight of at least approximately 100 kg. The material may not include binding wires or bands.
According to a further feature of the present invention, the process can further include orienting the plane at an angle between approximately 0° and 90° relative to the horizontal. The plane may be oriented at an angle between approximately 20° and 50°. Moreover, the plane can be oriented at an angle sufficient to substantially evenly distribute the material over the at least three hammer rollers in the transport direction.
According to still another feature of the present invention, the app
Flecken Peter
Peters Erich
Udelhofen Jakob
Greenblum & Bernstein P.L.C.
Nguyen Dean T.
Voith Sulzer Papiertechnik Patent GmbH
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