This application is the U.S. national phase of International Application No. PCT/FI2009/050495 filed 10 Jun. 2009 which designated the U.S. and claims priority to FI Patent Application No. 20080401 filed 11 Jun. 2008, the entire contents of each of which are hereby incorporated by reference.
The present invention relates to an apparatus for storing rolling material in an open storage pile and more specifically to an apparatus for stacking and reclaiming material, i.e. to a stacker/reclaimer. Most preferably the invention relates to storing of wood chips, but it is applicable for storing other granular material such as wood bark, coal, corn or fine-grained material.
Storage piles are needed for homogenizing the material and on the other hand for blending possibilities. The stacker/reclaimer for this kind of storage pile comprises e.g. a center column, a stacker conveyor and a reclaimer conveyor. The center column supports concentrically the upper stacker conveyor and the lower reclaimer conveyor. The stacker conveyor adds loose material in the pile, while the reclaimer conveyor conveys the material from the pile towards the slewing center of the stacker/reclaimer. In the slewing center the material to be discharged is transferred to an underground conveyor removing the material. Thus, the stacker/reclaimer is rotatable and creates an arched pile around itself.
In prior art stacker/reclaimers the center column is support with inclined, massive steel and concrete supports onto an equalizing hopper or onto the ground surface. Additionally, the concrete construction of the center column extends up to the slewing hinge. This kind of construction is heavy and expensive to build, as all the forces of the center column, also vertical, must be supported with inclined supports.
In known solutions, with a typical reclaiming capacity of 500-2500 i-m3/h (=loose cubic meters per hour, e.g. chips), the depth of the equalizing hopper's foundation has to be approximately 6 meters due to the construction of the stacker/reclaimer. A deep equalizing hopper often causes difficulties. In many places water is met closer to the ground surface, which makes digging the tunnel and the equalizing hopper difficult and expensive. Even if groundwater would not cause a problem, making a deep equalizing hopper and a tunnel is in every case expensive with massive earth-moving work. In addition, the support of the center column requires a large amount of steel and it is challenging in constructional view, and expensive to build.
A totally novel type of equalizing hopper and center column of a stacker/reclaimer has been developed. The center column of the stacker/reclaimer is supported directly to the bottom the equalizing hopper foundation between or beside the conveyors through the equalizing hopper, whereby vertical forces can be directed directly to the ground. This allows using significantly simpler and lighter support constructions than in prior art solutions. The base plate of the foundation, on which the center column is supported, is dimensioned so thick that it can carry the vertical loads and so wide that it can transmit the vertical loads to the ground. In accordance with the conditions (size of the storage, load bearing capacity of the ground etc.) the plate can easily be built adequately wide. Lateral support is arranged onto the walls of the equalizing hopper's foundation. Further, in accordance with the invention the center column is supported against lateral loads on an upper level, in the vicinity of the bottom level of the storage place, i.e. close to the ground level to the walls of the equalizing hopper's foundation with lateral support beams and intermittent walls made of concrete and steel. Symmetrical constructions lead to symmetrical loadings of the walls. The wall surfaces, in turn, together with the bottom plate, contribute to the stabilization of the foundation to be solid in relation to the surrounding ground. This kind of construction according to the invention is also significantly easier to implement, due to its simplicity and its forms that are constructionally clear and advantageous.
In a solution according to the invention, the number of conveyors that transfer the reclaimed material from the reclaimer conveyor to the discharging underground conveyor can be one or more, preferably two. These conveyors can be screw conveyors or other conveyors suitable for the purpose.
A solution according to the invention allows building the equalizing hopper symmetrical, with optimal dimensions. Symmetricity, in turn, is advantageous in view of the strength of the structures and additionally it allows using similar conveyors and components. Under the ground surface the form of the center column is essentially quadrangular, preferably square, whereby it is easier and cheaper to construct. The part of the center column that is above ground level is, after the transfer zone, according to the invention constructed of steel, with an essentially circular cross section. The support according to the invention allows building the equalizing hopper low, even-down to approximately 4.5 meters, whereby the problems of prior art are avoided.
Advantages that may be achieved with the invention include e.g. the following:
In the following, the invention is disclosed in more detail with reference to the appended figures, of which
Although the above description relates to an embodiment of the invention that is in the light of present knowledge considered the most preferable, it is obvious to a person skilled in the art that the invention can be modified in many different ways within the broadest possible scope defined by the appended claims alone.
Number | Date | Country | Kind |
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20080401 | Jun 2008 | FI | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FI2009/050495 | 6/10/2009 | WO | 00 | 12/13/2010 |
Publishing Document | Publishing Date | Country | Kind |
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WO2009/150301 | 12/17/2009 | WO | A |
Number | Name | Date | Kind |
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3621978 | Smith | Nov 1971 | A |
3794387 | Christensen et al. | Feb 1974 | A |
4629060 | Schlegel et al. | Dec 1986 | A |
6095742 | Campbell | Aug 2000 | A |
20050040015 | Schlegel et al. | Feb 2005 | A1 |
20050155845 | Webb | Jul 2005 | A1 |
Number | Date | Country |
---|---|---|
197748559 | Jun 1998 | AU |
92 12 512 | Dec 1992 | DE |
197 50 773 | May 1998 | DE |
0 090 981 | Oct 1983 | EP |
WO 03086912 | Oct 2003 | WO |
Entry |
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International Search Report for PCT/FI2009/050495, mailed Feb. 9, 2010. |
Written Opinion for PCT/FI2009/050495, mailed Feb. 9, 2010. |
Number | Date | Country | |
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20110094857 A1 | Apr 2011 | US |