Heating – Work feeding – agitating – discharging or conveying... – Having closure or seal for work feeder's entrance passage
Patent
1996-02-07
1998-06-23
Bennett, Henry A.
Heating
Work feeding, agitating, discharging or conveying...
Having closure or seal for work feeder's entrance passage
266183, 34242, D06B 2318
Patent
active
057696292
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sealing apparatus for sealing the inlet and/or the outlet of an atmosphere heat treatment furnace for continuously atmosphere-heat-treating strips, such as a bright annealing furnace for treating metal strips.
2. Description of the Related Art
Conventionally, as shown in FIG. 12, strips such as metal strips are treated continuously in an atmosphere facility. For example, a metal strip 1 is subjected to heat treatment for annealing in a nonoxidizing atmosphere in a vertical bright annealing furnace. The metal strip 1 and a bright annealing furnace 2 are grounded electrically by a grounding line 3. The direction of the metal strip 1 is changed by rolls 4 disposed at appropriate positions, and the metal strip 1 enters the bright annealing furnace 2 from a sealed portion 5 of an inlet of furnace 2 and is delivered from a sealed portion 6 of an outlet thereof.
The bright annealing furnace 2 continuously anneals the metal strip 1, such as stainless steel strips, other alloy steel strips, high-alloy strips, copper alloy strips and copper strips, while preventing oxidation. For this purpose, a combustible gas having the danger of causing explosions and fires, for example, a gas including hydrogen gas, such as ammonia decomposition gas or a mixture gas of hydrogen and nitrogen, is used as a furnace atmosphere gas 7. Therefore, the sealing performances at the sealed portions 5 and 6 of the inlet and outlet, respectively, are very important to ensure the quality of the products and the safety of operation. The above-mentioned grounding line 3 also functions as a part of safety measures.
A typical prior art of sealing apparatus for sealing an inlet or an outlet is disclosed, for example, in Japanese Examined Patent Publication JPB1 42-18893 (1967). In such prior art arrangement, the metal strip 1 is held between a pair of elastic rolls 8 at the sealed portions 5 and 6 of the inlet and the outlet, respectively. A seal plate 9 pushes the outer peripheral side surface of the elastic roll 8 to hermetically seal the boundary between the casing 10 of the bright annealing furnace 2 and each elastic roll 8.
In the sealing apparatus wherein the metal strip 1 is held between the elastic rolls 8 such as the above-mentioned prior art arrangement, when the metal strip 1 is thick as shown in FIG. 13, it is inevitable that clearances 1a and 1b are generated at the edges of the metal strip 1, thereby lowering the sealing performance. Furthermore, since the metal strip 1 having a certain thickness is held between the elastic rolls 8 during operation, the portions of the elastic rolls 8 contacting the sharp edges of the metal strip 1 are subjected to large cutting forces at all times and are apt to be dented or damaged due to friction. In the case where such dents are generated on the pair of elastic rolls 8, the clearances are increased, thereby further lowering the sealing performance. To solve this problem, the seal plate 9 comprising a nonwoven cloth 12, an elastic member 13 and a backup plate 14 pushes the outer peripheral side surface of the elastic rolls, as shown in FIG. 14.
The backup plate 14 is divided into a plurality of segments in the axial direction of the elastic roll 8 so that the nonwoven cloth 12 closely contacts the elastic roll 8 even when the elastic roll 8 is partially dented because of friction. Moreover, as shown in FIG. 15, as the passing speed of the metal strip 1 or the rotation speed of the elastic roll 8 increases, the oxygen in the outside air (oxygen O.sub.2 in the air or oxygen in water vapor H.sub.2 O in the air) is increasingly taken into the bright annealing furnace 2 because of the minute uneven portions on the surface of the metal strip 1 and the minute uneven portions on the surface of the elastic roll 8, thereby deteriorating the dew point of the atmosphere gas in the furnace, generating coloration (a serious defect caused during treatment in the bright annealing furnace) and significantly lowering the quali
REFERENCES:
patent: 3291468 (1966-12-01), Albertsen et al.
patent: 4190966 (1980-03-01), Sando et al.
New U.S. Patent Application filed Feb. 7, 1996 Corresponding to PCT/JP95/01101, filed Jun. 5, 1995, by Teruhisa Nakamura, entitled "Sealing Apparatus for Inlet/Outlet of Atmosphere Facility".
English Abstract of Japanese Patent, Publication No. 62287020A (Dec. 1987).
English Abstract of Japanese Patent, Publication No. 05214450A (Aug. 1993).
English Abstract of Japanese Patent, Publication No. 06346155A (Dec. 1994).
Bennett Henry A.
Nisshin Steel Co. Ltd.
Wilson Gregory
LandOfFree
Sealing apparatus for inlet/outlet of atmosphere heat treatment does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sealing apparatus for inlet/outlet of atmosphere heat treatment , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sealing apparatus for inlet/outlet of atmosphere heat treatment will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1388737