Electrically heated outlet system

Claim 2

An improved electric furnace for melting and refining glass, including a chamber for containing a bath of molten glass having a bottom wall and an upstanding peripheral wall; electrode means for supplying electrical energy to said bath; and passageway means extending through said sidewall for delivering molten glass from said bath to channel means for receiving glass, wherein the improvement comprises: said passageway means includes a conduit made from an electrically conductive refractory metal; said channel means includes electrode means; and means for selectively supplying voltage across at least one electrode of said furnace electrode means and said electrode means in said channel means to establish a flow of electrical currents from said at least one furnace electrode to said conduit, through said electrically conductive conduit, and to said electrode means of the channel means, whereby said current flow in said channel means heats the glass therein, and heat transferred therefrom at least partially melts glass-forming materials initially within said conduit.

Claim 3

The improved electric furnace of claim 1 wherein said conduit is made from molybdenum.

Claim 4

The improved electric furnace of claim 2 further including a flange member which is also made from molybdenum and which is secured to said conduit at a position between said furnace sidewall and said channel means, the flange having a flat-sided annular shape of a selected outer diameter; and means for protecting the flange and conduit from oxidation comprising: two refractory washer-like members, with one being adjacent one side of the flange, and the other being adjacent the other side of the flange, and both having outer diameters greater than the diameter of the flange; an annular metal collar which partially envelopes said washer-like refractory members, said collar having a circumferential portion and side portions extending radially inwardly from said circumferential portion, with the innermost edges of the side portions of said collar being spaced apart from said conduit; and means for removing heat from said collar to thereby cool and solidify thermoplastic material which may initially flow between said collar and said washer-like refractory members, and said washer-like members and said flange.

Claim 5

In combination with furnace means for melting thermoplastic material, at least one outlet system for delivering molten thermoplastic material from said furnace means into channel means for receiving molten material from the furnace means comprising: an electrically conductive refractory conduit having an inlet end positioned within a lower portion of furnace means for melting thermoplastic material and an exit end positioned in channel means adjacent the furnace means for receiving molten thermoplastic material from the furnace means; first electrode means within the furnace means; second electrode means in the channel means; the first and second electrode means respectively positioned relative to the inlet and exit ends of the conduit to establish electric current paths from the first electrode means through thermoplastic material in the furnace means to the inlet end of said conduit, through the electrically conductive conduit to the exit end thereof, and from the exit end through thermoplastic material in the channel means to the second electrode means; and means for supplying electrical current to the first and second electrode means to provide current along said paths, thereby electrically heating thermoplastic material in the channel means between the second electrode means and the conduit exit end, whereby thermoplastic material initially in the conduit will be at least partially melted by heat transferred from the heated thermoplastic material in the channel means.

Claim 6

In combination with furnace means for melting thermoplastic material, at least one outlet system for delivering molten thermoplastic material from said furnace means into channel means for receiving molten material from the furnace means comprising: an electrically conductive refractory conduit having an inlet end positioned within a lower portion of furnace means for melting thermoplastic material and an exit end positioned in channel means adjacent the furnace means for receiving molten thermoplastic material from the furnace means; first electrode means within the furnace means; second electrode means in the channel means; the first and second electrode means respectively positioned relative to the inlet and exit ends of the conduit to establish electric current paths from the first electrode means through thermoplastic material in the furnace means to the inlet end of said conduit, through the electrically conductive conduit to the exit end thereof, and from the exit end through thermoplastic material in the channel means to the second electrode means; and means for supplying electrical current to the first and second electrode means to provide current along said paths, thereby electrically heating thermoplastic material in the channel means between the second electrode means and the conduit exit end, whereby thermoplastic material initially in the conduit will be at least partially melted by heat transferred from the heated thermoplastic material in the channel means.

Claim 7

The outlet system of claim 4 wherein said first electrode means comprises at least one electrode of a plurality of electrodes situated in said furnace means, with the plurality of electrodes being connected to second means for selectively supplying electrical energy to heat thermoplastic material in said furnace means.

Claim 8

The outlet system of claim 4 wherein the conduit is made from molybdenum.

Claim 9

The outlet system of claim 6 further including a flange member which is also made of molybdenum and is secured to the conduit at a position between said furnace means and said channel means, the flange having a flat-sided washer-like shape of a selected outer diameter; and means for protecting the flange and conduit from oxidation comprising: two refractory washer-like members, with one being adjacent one side of the flange and the other being adjacent the other side of the flange, and both having outer diameters greater than the diameter of the flange; an annular metal collar which partially envelopes said washer-like refractory members, said collar having a circumferential portion and side portions extending radially inwardly from said circumferential portion, with the innermost edges of the side portions of said collar being spaced apart from said conduit; and means for removing heat from said collar to thereby cool and solidify thermoplastic material which may initially flow between said collar and said washer-like refractory members, and said washer-like members and said flange.

Claim 10

The outlet system of claim 7 further including a layer of refractory material between a side portion of said collar and said furnace means, and another layer of refractory material between the other side portion of said collar and said channel means.

Claim 11

The outlet system of claim 7 further including means for purging oxygen-containing gases from within said means for protecting the flange and conduit from oxidation.

Claim 12

Apparatus for heating glass-forming material within a delivery conduit of a glass melting furnace comprising: a delivery conduit extending laterally through a vertical wall of a glass melting furnace into a channel for receiving glass melted within said furnace, said conduit having an inlet end in said furnace and an exit end in said channel; said delivery conduit being made from an electrically conductive refractory metal; at least one electrode in said furnace; at least one electrode in said channel; means connected to said electrodes in said furnace and said channel for establishing the flow of electrical currents between said at least one furnace electrode and said conduit inlet end, through said electrically conductive conduit, and between said exit end of said conduit and said at least one channel electrode, whereby said currents between said at least one furnace electrode and said exit end of said conduit heat the glass-forming materials thereat, and radiated heat from said heated material at least partially melts glass-forming material within said conduit.

Claim 13

Apparatus for heating glass-forming material within a delivery conduit of a glass melting furnace comprising: a delivery conduit extending laterally through a vertical wall of a glass melting furnace into a channel for receiving glass melted within said furnace, said conduit having an inlet end in said furnace and an exit end in said channel; said delivery conduit being made from an electrically conductive refractory metal; at least one electrode in said furnace; at least one electrode in said channel; means connected to said electrodes in said furnace and said channel for establishing the flow of electrical currents between said at least one furnace electrode and said conduit inlet end, through said electrically conductive conduit, and between said exit end of said conduit and said at least one channel electrode, whereby said currents between said at least one furnace electrode and said exit end of said conduit heat the glass-forming materials thereat, and radiated heat from said heated material at least partially melts glass-forming material within said conduit.

Claim 14

The apparatus of claim 10 wherein said furnace includes other electrodes, and said at least one electrode in said furnace is also connected to a second means for selectively establishing the flow of electrical currents through glass-forming materials between said at least one electrode and said other electrodes in said furnace.

Claim 15

The apparatus of claim 10 wherein said conduit is made from molybdenum.

Claim 16

The apparatus of claim 12 further including an annular flange member which is also made from molybdenum and which is positioned to said conduit between said furnace and said channel, the flange being protected from exposure to the ambience by an assembly comprising: two refractory washer-like members, with one being adjacent one side of the flange and the other being adjacent the other side of the flange, and both having outer diameters greater than the diameter of the flange; an annular metal collar which partially envelopes said washer-like refractory members, said collar having a circumferential portion and side portions extending radially inwardly from said circumferential portion, with the innermost edges of the side portions of said collar being spaced apart from said conduit; and means for removing heat from said collar to thereby cool and solidify thermoplastic material which may initially flow between said collar and said washer-like refractory members, and said washer-like members and said flange.