Abstract: Systems and methods are provided for controlling temperature in a glass forehearth. In one implementation, a system includes at least one burner disposed in said forehearth, a manifold coupled to said burner, a combustion fuel supply coupled to said burner, a combustion air blower for delivering ambient air under pressure to said manifold, and a controller coupled to said burner for controlling operation of said burner. The system may include a temperature sensor operatively coupled downstream of the blower for providing to the controller a temperature signal indicative of temperature of air delivered to the manifold by the blower. The controller may be responsive to the temperature signal for controlling operation of the burner as a function of current temperature of air fed to the manifold. Operation of the burner may also be controlled as a function of an average air temperature over a preceding time duration.

Abstract: Systems and methods are provided for controlling temperature in a glass forehearth. In one implementation, a system includes at least one burner disposed in said forehearth, a manifold coupled to said burner, a combustion fuel supply coupled to said burner, a combustion air blower for delivering ambient air under pressure to said manifold, and a controller coupled to said burner for controlling operation of said burner. The system may include a temperature sensor operatively coupled downstream of the blower for providing to the controller a temperature signal indicative of temperature of air delivered to the manifold by the blower. The controller may be responsive to the temperature signal for controlling operation of the burner as a function of current temperature of air fed to the manifold. Operation of the burner may also be controlled as a function of an average air temperature over a preceding time duration.

Abstract: Systems and methods are provided for controlling temperature in a glass forehearth. In one implementation, a system includes at least one burner disposed in said forehearth, a manifold coupled to said burner, a combustion fuel supply coupled to said burner, a combustion air blower for delivering ambient air under pressure to said manifold, and a controller coupled to said burner for controlling operation of said burner. The system may include a temperature sensor operatively coupled downstream of the blower for providing to the controller a temperature signal indicative of temperature of air delivered to the manifold by the blower. The controller may be responsive to the temperature signal for controlling operation of the burner as a function of current temperature of air fed to the manifold. Operation of the burner may also be controlled as a function of an average air temperature over a preceding time duration.

Abstract: Systems and methods are provided for controlling temperature in a glass forehearth. In one implementation, a system includes at least one burner disposed in said forehearth, a manifold coupled to said burner, a combustion fuel supply coupled to said burner, a combustion air blower for delivering ambient air under pressure to said manifold, and a controller coupled to said burner for controlling operation of said burner. The system may include a temperature sensor operatively coupled downstream of the blower for providing to the controller a temperature signal indicative of temperature of air delivered to the manifold by the blower. The controller may be responsive to the temperature signal for controlling operation of the burner as a function of current temperature of air fed to the manifold. Operation of the burner may also be controlled as a function of an average air temperature over a preceding time duration.

Abstract: Apparatus for controlling rate of molten glass flow through a forehearth that includes a flume disposed in the forehearth for restricting the width of the forehearth to glass flow, such that there is a difference in level of molten glass in the forehearth upstream and downstream of the flume. Sensors measure the level of molten glass upstream and downstream of the flume, and a controller is responsive to the sensors for determining rate of molten glass flow through the forehearth as a function of a difference in molten glass level between the sensors. Rate of glass flow through the forehearth is controlled as a function of the difference in glass level across the flume as compared with a desired flow rate set by an operator.

Abstract: A forehearth (20) for cooling glass from a melting furnace as it flows to a feeder bowl (28) from which it is discharged to a forming machine. The forehearth is in the form of an elongate, horizontally extending insulated trough (26) with a roof formed by a longitudinally extending series of roof block elements (30), each of which is of one-piece construction and extends completely across the width of the insulated trough. The downwardly facing surface of each roof block element is contoured to incorporate concave portions (30a, 30b) near the edges of the forehearth, a concave portion (30c) above the center of the forehearth and convex portions (30d, 30e) separating the center concave portion from the side concave portions to substantially impede heat transfer between the side concave portions and the center concave portion.

Abstract: A forehearth (20) for cooling glass from a melting furnace as it flows to a feeder bowl (28) from which it is discharged to a forming machine. The forehearth is in the form of an elongate, horizontally extending insulated trough (26) with a roof formed by a longitudinally extending series of roof block elements (30), each of which is of one-piece construction and extends completely across the width of the insulated trough. The downwardly facing surface of each roof block element is contoured to incorporate concave portions (30a, 30b) near the edges of the forehearth, a concave portion (30c) above the center of the forehearth and convex portions (30d, 30e) separating the center concave portion from the side concave portions to substantially impede heat transfer between the side concave portions and the center concave portion.

Abstract: Apparatus for forming a cased glass stream having an inner core glass surrounded by an outer casing glass includes a first orifice for receiving core glass from a first source, and a second orifice vertically spaced beneath and aligned with the first orifice. A chamber surrounds the second orifice and communicates with the second orifice through a metering gap between the first and second orifices. Casing glass is delivered from a second source to the chamber such that glass flows by gravity through the orifices from the first and second sources to form the cased glass stream. The first and second orifices are disposed in respective first and second orifice rings of refractory composition. The first orifice ring has a peripheral flange and an interior passage for glass flow from the first source to the first orifice.

Abstract: A forehearth (20) for cooling glass from a melting furnace as it flows to a feeder bowl (28) from which it is discharged to a forming machine. The forehearth is in the form of an elongate, horizontally extending insulated trough (26) with a roof formed by a longitudinally extending series of roof block elements (30), each of which is of one-piece construction and extends completely across the width of the insulated trough. The downwardly facing surface of each roof block element is contoured to incorporate concave portions (30a, 30b) near the edges of the forehearth, a concave portion (30c) above the center of the forehearth and convex portions (30d, 30e) separating the center concave portion from the side concave portions to substantially impede heat transfer between the side concave portions and the center concave portion.

Abstract: A conditioning section of a forehearth is disclosed with sidewall electrodes for Joule effect heating of glass positioned and connected to confine the current and Joule effect heating separately to the side portions of the molten glass flow path therein. Separate circuits, controls, temperature sensors and temperature set point control means are provided for the sidewall electrodes on each side. Glass temperature across the flow path is controlled and can be adjusted by separately controlling the flow of Joule effect current along each side of the flow path through manual or automatic, thermally actuated, controls for each side.

Abstract: Molten glass entering from a refiner is conditioned, in an optimum operation, such that its temperature along the center of the flowing glass just in advance of its entry into the feeder, will be of equal temperature near the surface near the bottom and intermediate these two points. A tri-level thermocouple is positioned along the center line at approximately nine inches from the feeder for monitoring these temperatures, and to serve as an aid to the operator in controlling the actual glass temperature. Positioned at opposite sides of the forehearth, approximately eight inches from the center line, are tri-level thermocouples. The three couples will be positioned at the same relative depths as those at the center line. The center thermocouple on the right side will have its output used as the control temperature for a temperature override circuit connected to the electrodes.

Abstract: Disclosed is a method and apparatus for preventing the formation of blisters in an electrically-heated forehearth that utilizes submerged electrodes connected to either a single or plural phase alternating current source. The electrodes are arranged so that Joule effect heating is effected by passing alternating current through the molten glass with the center tap of the secondary of the power transformer being connected to the positive side of a Direct Current source through a filter, while the negative side of the DC source is connected to a counter electrode, immersed in the glass at a point upstream of the forehearth.With this physical arrangement, the formation of blisters due to free electrons migrating to and collecting on some of the electrodes that are at different potentials than the others is prevented.

Abstract: A glassware forming machine including means for distributing gobs of molten glass to individual sections of the machine at a predetermined rate, drive means responsive to electrical power of a selected frequency generated by a power source for driving the gob distributing means at the predetermined rate and an automatic control means responsive to timing signals for controlling each of the individual sections in a predetermined timed sequence of steps for forming the glassware wherein the power source generates the timing signals at a frequency proportional to the selected frequency of the power source. Each piece of glassware is formed during a machine cycle which is related in duration to the gob distribution rate and typically is defined in terms of 360.degree.. The power source includes a timing pulse generator which synthesizes the timing signals from the power source electric power frequency at the frequency required for defining 360.degree. per machine cycle.