Glass melting method and apparatus
AssigneeHoya Corporation
InventorKazuo Ogino
Life of this patent
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Abstract
In a method of and an apparatus for melting glass having high reducing activity when melted, a glass raw material charged into a melting vessel having a wall formed of platinum or alloy thereof is heated and melted. Oxygen gas is supplied to an outer surface of the melting vessel to raise oxygen partial pressure within an atmosphere surrounding the melting vessel. The oxygen gas is caused to penetrate through the wall of the melting vessel, thereby supplying the penentrated oxygen to a layer of the molten glass which is in contact with an inner surface of the wall of the melting vessel, so that the layer of the molten glass is formed into a protective glass layer rich in oxygen, for protecting the wall of the melting vessel from the molten glass.
Claims16
A method of melting phosphate glass having high reducing activity when melted, said method comprising the steps of:
- charging a phosphate glass raw material into a melting vessel having a wall formed of either one of platinum and alloy thereof;
- heating the phosphate glass raw material within said melting vessel to melt it;
- and
- supplying oxygen gas to an outer surface of said melting vessel to raise oxygen partial pressure within an atmosphere surrounding said melting vessel so as to cause the oxygen gas to penetrate through the wall of said melting vessel, thereby supplying the penetrated oxygen to a layer of the molten phosphate glass which is in contact with an inner surface of the wall of said melting vessel, the concentration of oxygen being sufficient so that the layer of the molten phosphate glass is formed into a protective glass layer rich in oxygen, for protecting the wall of said melting vessel from the molten phosphate glass.
An apparatus for melting phosphate glass having high reducing activity when melted, said apparatus
- a melting vessel to be charged with a phosphate glass raw material, said melting vessel having a wall formed of either one of platinum and alloy thereof;
- means for heating the phosphate glass raw material within said melting vessel to melt it;
- surrounding means arranged to surround said melting vessel and cooperating with an outer surface of the wall of said melting vessel to define a first space between said surrounding means and said melting vessel;
- supply means for supplying oxygen gas to said space to raise oxygen partial pressure therewithin so as to cause the oxygen gas to penetrate through the wall of said melting vessel, thereby supplying the penetrated oxygen to a layer of the molten phosphate glass which is in contact with an inner surface of the wall of said melting vessel, so that the layer of the molten phosphate glass is formed into a protective glass layer rich in oxygen, for protecting the wall of said melting vessel from the molten phosphate glass;
- and
- said melting vessel including a substantially closed top wall for isolating a surface of the molten phosphate glass from said oxygen gas.
An apparatus for melting phosphate glass having high reducing activity when melted, said apparatus comprising:
- a melting vessel to be charged with a phosphate glass raw material, said melting vessel having a wall formed of either one of said platinum and alloy thereof;
- means for heating the phosphate glass raw material within said melting vessel to melt it;
- surrounding means arranged to surround said melting vessel and cooperating with an outer surface of the wall of said melting vessel to define a first space between said surrounding means and said melting vessel;
- first supply means for supplying oxygen gas to said space to raise oxygen partial pressure therewithin so as to cause the oxygen gas to penetrate through the wall of said melting vessel, thereby supplying the penetrated oxygen to a layer of the molten phosphate glass which is in contact with an inner surface of the wall of said melting vessel, so that the layer of the molten phosphate glass is formed into a protective glass layer rich in oxygen, for protecting the wall of said melting vessel from the molten phosphate glass;
- an outflow pipe formed of either one of platinum and alloy thereof and connected to a bottom of said melting vessel, for discharging the molten phosphate glass from said melting vessel, a tubular protective case formed of refractory material and arranged in such a manner that said outflow pipe extends along an axis of said tubular protective case, said tubular protective case having a wall cooperating with an outer peripheral surface of said outflow pipe to define a second space between said tubular protective case and said outflow pipe;
- and
- second supply means for supplying oxygen gas into said second space.
An apparatus for melting phosphate glass having high reducing activity when melted, said apparatus comprising:
- a melting vessel to be charged with a phosphate glass raw material, said melting vessel having a wall formed of either one of platinum and alloy thereof;
- means for heating the phosphate glass raw material within said melting vessel to melt it;
- surrounding means arranged to surround said melting vessel and cooperating with an outer surface of the wall of said melting vessel to define a space between said surrounding means and said melting vessel, said space being filled with metal oxide particles which do not react with the wall of said melting vessel;
- and
- supply means for supplying oxygen gas to said space to raise oxygen partial pressure therewithin so as to cause the oxygen gas to penetrate through the wall of said melting vessel, thereby supplying the penetrated oxygen to a layer of the molten phosphate glass which is in contact with an inner surface of the wall of said melting vessel, so that the layer of the molten phosphate glass is formed into a protective glass layer rich in oxygen, for protecting the wall of said melting vessel from the molten phosphate glass.
Dependencies are inferred from the claim text.