JP2003104730A5 - Vacuum degassing apparatus and vacuum degassing method - Google Patents

Description

[Claims]
(1)
A decompression housing in which the inside is decompressed by vacuum suction,
A vacuum degassing tank provided in the pressure reducing housing, through which molten glass flows and performs vacuum degassing,
An ascending pipe provided in communication with the vacuum degassing tank, sucks and raises the molten glass before vacuum degassing, and introduces the molten glass into the vacuum degassing tank.
A downcomer pipe is provided in communication with the vacuum degassing tank, and the molten glass subjected to vacuum degassing is lowered from the vacuum degassing tank and led out.
In at least a part of the flow direction of the flow path of the molten glass of the vacuum degassing tank, the bottom surface portion at the center in the width direction of the flow passage is convex, and the bottom surfaces at both ends located on both sides of the center bottom portion. A vacuum degassing apparatus for molten glass, wherein the portion is concave.
(2)
In the flow path of the molten glass in the vacuum degassing tank, the shortest distance from the top of the central convex bottom portion in the horizontal width direction to the molten glass surface in the horizontal width direction is the central depth D ₁ , and the concave bottom portions at both ends in the horizontal width direction. when the shortest distance from the bottom to the molten glass surface and Tanfuka of _{D 2,} the central depth _{D 1} is 20 to 500 mm, and Tanfuka of _{D 2} is a center depth _{D 1} 1.1 to 5 The vacuum degassing apparatus for molten glass according to claim 1, wherein the pressure is 0.0 times.
(3)
3. The bubble damping device which serves to stop outflow of bubbles generated by vacuum degassing to the downcomer side is provided in a flow path of the molten glass in the vacuum degassing tank. Vacuum degassing equipment for molten glass.
[ Claim 4 ]
A vacuum degassing method for molten glass using the vacuum degassing apparatus according to claim 1.

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vacuum degassing apparatus and a vacuum degassing method for molten glass for removing air bubbles from a continuously supplied molten glass.

Therefore, an object of the present invention is to further improve the vacuum degassing performance in the case where the bottom area of the flow path of the vacuum degassing tank is widened, to enable a vacuum degassing treatment of a large flow of molten glass, and to generate defective bubbles. It is an object of the present invention to provide a vacuum degassing apparatus and a vacuum degassing method for molten glass capable of obtaining a molten glass that does not need to be melted.

Further, the shortest distance from the top of the central convex bottom portion in the width direction to the molten glass surface in the flow path of the molten glass in the vacuum degassing tank is defined as the central depth D ₁ , and the concave bottom surfaces at both ends in the width direction. when the bottom parts to the shortest distance to the molten glass surface and Tanfuka of _{D 2,} the central depth _{D 1} is 20 to 500 mm, and Tanfuka of _{D 2} is a center depth _{D 1} of the 1.1 Preferably it is up to 5.0 times. In addition, it is preferable that a bubble damper that functions to stop the outflow of bubbles generated by vacuum degassing to the downcomer side is provided in the flow path of the molten glass in the vacuum degassing tank.
The present invention also provides a method for defoaming molten glass under reduced pressure using the vacuum defoaming apparatus of the present invention.