Drying and gas or vapor contact with solids – Apparatus – Rotary drums or receptacles
Reexamination Certificate
1998-04-16
2001-02-27
McDermott, Corrine (Department: 3744)
Drying and gas or vapor contact with solids
Apparatus
Rotary drums or receptacles
C034S122000, C034S124000
Reexamination Certificate
active
06192597
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. § 119 of German Patent Application No. 197 16 131.6 and, filed on Apr. 17, 1997, and of German Patent Application Nos. 197 43 517 297 17 556.4.3, filed Oct. 1, 1997, the disclosures of which are expressly incorporated by reference herein in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for treating a fibrous pulp web, e.g., a paper and/or a cardboard web. The fibrous pulp web may be guided either alone or together with at least one support belt, e.g., a draining belt, press belt, screen (sieve) belt, over at least one support face, which may be moving or stationary. The device may also include at least one sealing device positioned on a side of the fibrous pulp web located opposite the support face to strip away at least the majority of the bordering air layer that is entrained or swept in by the fibrous pulp web and/or support belt.
The present invention also relates to a sealing device that may be utilized in a fibrous pulp treatment device of the type generally described above.
2. Discussion of the Background Information
In a device of the type generally discussed above, and as discussed in, e.g., German Patent Application No. DE-A-44 20 242, a stripping strip extends transversely to a web run direction and is positioned across from one of two adjacent drying cylinders. The strip is mounted to swivel on a suction box arranged between both drying cylinders and a perforated deflection roll, and the suction box serves to suction the perforated deflection roll externally. During operation, the stripping strip, which is made of synthetic material or formed by a felt strip, is arranged radially to, and at a distance from, the one drying cylinder.
In German Patent Application DE 297 03 627, an outwardly-arched deflector is positioned against a web run direction in an inlet region of a vapor blow box arranged on an outer periphery of a press roll. A fibrous pulp web and a felt belt are guided over the press roll. Due to the deflector arranged at a distance from the fibrous pulp web, the bordering air layer is deflected at least in part to the exterior wall of the vapor blow box, via which the deflected air is led away.
SUMMARY OF THE INVENTION
The present invention provides a device of the type generally discussed above having a sealing device that substantially guarantees an optimal impermeability for entrained air, especially at higher operating speeds, and which is not sensitive to interfering matter, e.g., paper clots, etc. Further, a suitable sealing device for use in such devices is also provided.
The present invention, therefore, provides a device that includes a sealing device having a sealing disc (or strip or plate), that is either substantially straight or at least partially curved, that has a preferably elastic design and/or is arranged in a resilient, yielding position. In the sealing device of the present invention, the sealing disc may be adapted to be pressed against the fibrous pulp web or a support belt.
Because of the advantageous features of the present invention, a higher impermeability of the entrained air may be obtained in comparison to the wool-felt and air-knife seals of the prior art. In this regard, potential functional impairments are practically eliminated, particularly at higher speeds. Due to the elastic sealing, interfering matter that may arise, e.g., paper clots, may be admitted without any damage or without a loss of impermeability.
The press force is preferably adjustable. In addition or alternatively, a device for automatic subsequent adjustment of the press force may also be provided. Thus, an optimal operation or an optimal sealing is substantially guaranteed, regardless of the respective operational requirements.
With an embodiment in accordance with an exemplary embodiment of the present invention, the sealing disc extends transversely to the web run direction.
The sealing disc can be composed of, e.g., metal, synthetic material, fiber-reinforced synthetic material, or composite material.
It may be particularly advantageous if the sealing disc is positioned so that it can swivel. In this manner, the sealing disc can swivelled away from the support face concerned, e.g., in order to unimpededly pull a new support belt into place.
In an expedient, practical embodiment, the sealing disc may be fastened to a swivel mounting from which it preferably can be removed. The sealing device or its sealing disc can thus be exchanged easily and quickly, should the need arise.
In embodiments that are preferred in practice, the sealing disc can be pressed, e.g., mechanically, pneumatically, and/or hydraulically. In this manner, a mechanical pressing of the sealing disc may be provided, e.g., via at least one rod, at least one press screw, and at least one spring or something device. In the event of a pneumatic and/or hydraulic pressing, the sealing disc may be imparted upon by at least one cylinder/piston unit.
The sealing device may be positioned, e.g., in an inlet region of a vapor blow box. In an expedient, practical embodiment, it may be positioned in the inlet region of a vapor blow box located on an exterior periphery of a press roll, over which the fibrous pulp web, and, if appropriate, the support belt is guided.
In this arrangement, the sealing device is expediently mounted on the vapor blow box or positioned so that it may swivel.
The sealing unit can be positioned, e.g., in a run-off area of a drying cylinder, i.e., where the fibrous pulp web and a support belt run off the drying cylinder to be subsequently guided to a suctioned, perforated, and/or grooved deflection roll associated with an exterior suction box.
The sealing device may be preferably disposed in front of the run-off area, i.e., relative to the web run direction.
If a sealing device is associated with such a suction box, it can then be mounted on the suction box, or positioned to swivel. Even when using other ventilation devices, the sealing device may be mounted on the ventilation device utilized.
If the fibrous pulp web and, if appropriate, at least one support belt is guided over a curved face, e.g., formed by a press roll, a drying cylinder, etc., then the sealing disc of the sealing device may be positioned to lie on a side of the fibrous pulp web located opposite the support face, i.e., the non-contacting surface, at least substantially tangential to the fibrous pulp web or the respective support belt.
In an expedient, practical embodiment, the sealing disc may be positioned to lie adjacent to a peripheral region that extends transverse to the web run direction of the fibrous pulp web or the respective support belt, while preferably being positioned in an area of its opposing edge, so that it can swivel. Thus, it is preferable if at least the peripheral region of the pressed sealing disc lying adjacent to the fibrous pulp web or to the respective support belt is arched in the press or swivel plane.
The sealing device in accordance with the present invention may include a sealing element having an elastic design and/or a resilient, yielding position. Additional devices may be provided to hold the sealing element at least at a minimum distance from the web or the support belt, if the web or the support belt has reached an operating speed that can be predetermined. A sealing device of this type may be used, e.g., in a device of the type discussed previously.
An inlet nip may be preferably formed between the sealing element and the web or the support belt.
With a sealing device of this kind, a dynamic sealing can also be obtained, which, e.g., is also suitable for stabilizers. At increasing speeds, the sealing element may be thereby lifted by a portion of the bordering air layer, so that, at least during normal operations, a contactless sealing occurs. In this manner, wear is substantially avoided. In any event, a smaller air flow volume is let through, which is advantageous, and the main flow may be blocked off. From th
Joos Uwe
Kahl Peter
Klein Karl-Heinz
Muller Wolfgang
Oechsle Markus
Drake Malik N.
Greenblum & Bernstein P.L.C.
McDermott Corrine
Voith Sulzer Papiermaschinen GmbH
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