Presses – Plural presses – Stacked boxes or plates
Reexamination Certificate
2002-07-15
2003-12-30
Ostrager, Allen (Department: 3725)
Presses
Plural presses
Stacked boxes or plates
C100S214000, C100S325000, C156S228000
Reexamination Certificate
active
06668713
ABSTRACT:
FIELD OF THE INVENTION
My present invention relates to a platen press and, more particularly, to a multiplaten press for the production of boards from wood materials.
BACKGROUND OF THE INVENTION
Platen presses and especially multiplaten presses are used for the pressing of mats of materials containing wood inch boards. Such materials can include wood fibers and wood particles or sawdust, with or without binders, usually synthetic resin binders, which may or may not be heat-activatable and where the platens are usually arrayed one above the other to form press gaps.
The platen press systems with which the invention is primarily concerned are those which provide the press with a suction unit for drawing off by suction gases produced during the pressing of the boards. The press platens in this case are heated platens and the boards which are produced are particle board, OSB (oriented strand board) or MDS (medium densified fiber) board.
The mats of the wood material to be pressed are usually fed to the press gaps between the platens on charging plates or trays, charging screens or sieves or like supports or are supplied to the press by belt feeders. The press can then be closed and the mats pressed to boards within the press gap. During the hot pressing process, steam and gases can be evolved which, without the suction unit, would be released into the atmosphere and might be an environmental contaminant. In the processes with which the invention is concerned, the evolved gasses and steam are drawn off by the suction unit and can be trapped in a gas cleaner without being released into the atmosphere. Those gases may include gases evolved by any binder which may be combined with the wood chips, particles or fibers as well as those evolved by the wood materials themselves.
The platen press is usually preceded by a charging device for supplying the mats to the platens and by an emptying or charging device which removes the boards from the press. Units for drawing off the fumes by suction have, in the past, included relatively large hoods or enclosures which generally encompass at least the press and the press-emptying apparatus. As a consequence large screen blowers were required to handle the comparatively large volumes of gas (evolved vapors and ambient air) which were required. For example, the suction unit frequently was required to draw off not only the evolved fibers but also cooling air which had to be supplied to the press.
The drawn off gases required processing, for example with after-burners or the like to destroy the drawn-off vapors. Frequently the proportion of combustibles in the drawn off gas was insufficient to permit effective destruction of the vapors and it was necessary to add fuel to the system to ensure destruction of the evolved vapors. The operation was, therefore, expensive and the equipment evolved had to be sizable.
Multiplaten presses have been provided heretofore with spacers or spacer frames between the platens and wherein heat-resistant seals could be provided between the platens. The platens were provided with gaps running in the longitudinal direction of the platens and which were connected by transverse passages so that the press gaps themselves were interconnected. In such a system the evolved gas could be collected by a pipe system in a tank. The pipe system could use flexible lengths of pipe which could be provided on opposite sides of the platen as, for example, in U.S. Pat. No. 4,409,170. The systems described in this patent are also expensive and in many cases there is insufficient room alongside the press platen to provide the duct work such systems require.
OBJECTS OF THE INVENTION
It is, therefore, the principal object of the present invention to provide an improved platen press, especially a multiplaten press, which is not only of simpler construction than those provided heretofore and can be operated reliably and economically to evacuate evolved gases and steam, but which is also of simpler construction and space-saving design.
More specifically, it is an object of the present invention to provide a platen press with improved and evacuation of vapor from the press gap. Another object of this invention is to provide a platen press which obviates drawbacks of earlier systems.
SUMMARY OF THE INVENTION
These objects and others which will become apparent hereinafter are attained, in accordance with the invention, in a platen press for the pressing of mats of wood material into pressed board which comprises:
a plurality of platens disposed one above another between upper and lower press sides and defining press gaps between then for receiving wood-containing mats and pressing the mats to form boards;
seals between the platens around the gaps for sealing the gaps upon closing of the press;
passages formed in the platens and communicating with one another and with the gaps inwardly of the seals for forming at least one evacuating duct; and
at least one suction conduit on one of the sides of the press and communicating with the duct at least in a closed position of the press for evacuating gases evolved from the mats during pressing thereof.
According to the invention, therefore, a plurality of platens arranged one above another in the multiplaten press define press gaps between them, each of which is adapted to receive a mat of wooden material so that when the press is closed and the material is compressed between the heated platen, vapors are evolved which are drawn off by a suction unit.
According to the invention, seals are arranged around the periphery of the press platens around the press gaps and seal these gaps upon closure of the press. Each of the press platens can have one or more passages which, upon closure of the press, form evacuation ducts communicating with the press gaps and the upper side of the press and/or the lower side of the press for one or more conduits which communicate with the evacuation ducts.
As a consequence, a direct evacuation of the released vapors is possible since the press gaps themselves are peripherally sealed and the suction conduit on one of the upper or lower sides of the press can directly evacuate the communicating press gaps through passages formed in the platens.
As a consequence it is no longer necessary to evacuate ambient or cooling air with the evolved vapors and in large volumes. Rather the evolved vapors can be sucked off and efficiently burned so that the platen press according to the invention can operate completely in an environmentally sound manner.
Because the external duct work along the sides of the platens is not required, the construction of the press is simplified and the press can take up less space.
The conduits, according to the invention, communicate with the passages at the ends of the platens and press via communicating passages formed in the platens within the seals. The conduits in the upper and/or lower sides of the press ensure that the press will be laterally free from conduits and either rigid or flexible duct work and thus achieve an economy of construction and space which has not been possible heretofore. The conduits, usually a bundle of conduits connected together and to a common suction blower, can be provided at each end of the press in one or the other of the fixed press plates, e.g. the upper press plates so that there is no relative movement between the conduits or between the conduit and the upper and lower press plates or beds.
The passages formed in the platens can be vertical and aligned so that they form continuous evacuating ducts running the full height of the stack of platens. These passages can be flush with one another.
The invention is applicable not only to multiplaten presses but also to single platen presses having an upper and lower press plate or bed. Only a passage in one or the other of these beds is then required to communicate with the evacuating duct formed by a passage at an end of the platen within the seal and communicating with the press gap.
While it is preferred to provide the conduit exclusively in the upper press platen, it has been fou
Dubno Herbert
Nguyen Jimmy T
Ostrager Allen
Siempelkamp Maschinen- und Anlagenbau GmbH & Co. KG
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