摘要:
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. Burners (32) are positioned along the opposed sides of the forehearth to fire transversely into the spaces underlying the side concave portions of the roof blocks, and cooling air passages (40) extend through the roof blocks to discharge cooling air transversely of the forehearth into the space underlying the center concave portion in direct contact with the glass in the forehearth. A plurality of exhaust openings (34, 42) for products of combustion from the burners and cooling air, respectively are positioned along the length of the forehearth to provide for longitudinal flow of products of combustion and cooling air at rates which are variable along the length of the forehearth.
摘要:
A method and apparatus for the production of colored glass includes the steps of diverting a stream of clear molten glass from at least one glass melting furnace through one or more transport channels to a color treatment chamber. Recycled cullet and color additive are added to a charging end of the treatment chamber. The treatment chamber is heated to melt the cullet and further heat the remaining feedstock to form a molten bath of colored glass which is thermally and chemically homogenized in the treatment chamber. Refractory rotary paddle wheels positioned in the transport channels regulate the flow rate and level of the molten glass and provide for selective shut off of individual glass streams. A glass level sensor is located in an outlet channel of the treatment chamber and is electrically coupled to a programmable controller to selectively regulate the rotational speed of the paddle wheels responsive to glass level fluctuations to maintain a controlled gob weight of colored glass supplied to the glass forming machine.
摘要:
A continuously flowing glass stream is conditioned and homogenized along a conditioning stretch, which extends from an entry side to at least one extraction point, and at the beginning of which there is a cooling zone, to which a homogenizing zone for the glass temperature is connected. This method is preferentially used for the manufacture of molded glass articles, such as containers and pressed articles. In order to achieve the necessary conditioning and homogenization, even at high throughputs, the glass stream in the cooling zone has a cross section with a depth/width ratio D/W of a maximum 0.6 or 0.5, or 0.4, or 0.3, or 0.2, whereby the maximum depth Dmax amounts toa) 300 or 250 or 200 mm when the cooling zone is situated in a working end or in a distribution channelb) 150 or 120 or 100 mm when the cooling zone is situated in a feeder or in a forehearthand, at least 30, or 40 or 50% of that amount of energy which corresponds to the necessary temperature reduction is removed from the glass bath per meter of flow path at the beginning of the cooling zone.
摘要:
The present invention provides a molten glass conveying apparatus comprising a channel (4) along which molten glass may flow, a roof structure (6) over the channel (4) and extending between the two sides thereof and at least one nozzle (28) in the roof structure (6) through which a heating fluid may be passed, wherein in use the direction of the output of the heating fluid from the nozzle (28) is substantially along the channel (4) whereby at least one side portion of the molten glass is heated.
摘要:
The device comprises a three-dimensional grid of thermocouples which are immersed in a fluid, which is moving in a covered channel and has a temperature above that of its environment. Apertures in the sheathing of the channel can be progressively closed by shutters so as to control the cooling of the fluid through an outgoing radiation through the apertures. Burners with a variable intensity are placed within the channel and allow to heat up the fluid in the vicinity of each burner. The position of each shutter and the fuel flow to each burner are commanded severally, based on the values emitted by the ensemable of the thermocouples in order to obtain a homogeneous repartition of the temperature of the fluid, transversally with respect to the channel.
摘要:
A process for providing a thermally homogeneous flow of molten glass comprises introducing a stratified liquid layer of non-volatile evaporation resistant materials having density smaller than that of the molten glass, onto the surface of the molten glass contained within a feeding section of a forehearth.
摘要:
Forehearths for use in glass production comprise a refractory trough (52) for molten glass with an insulating roof thereover, means for heating glass in the trough and means for blowing cooling air across the inside of the roof surface; the forehearth being constructed of at least two sections (A, B and C) which have different insulating characteristics from each other. Preferably the forehearth roof is made up of prefabricated block members of refractory material lying side by side and each of which member spans across the trough. Different insulation is provided over the prefabricated block members to provide different insulating characteristics within sections of the forehearth. The invention also provides prefabricated members for use in the construction of the forehearth according to the present invention.
摘要:
A container between the output of a melting furnace wherein the molten mass is also refined, such as for glass, and the ducts to a plurality of forming machines comprising a larger first zone and a plurality of smaller second zones corresponding to each forming machine, in which container the molten mass is controlled in temperature above and below its liquid level as it flows through the first and second zone toward a forming machine so that the cross-sectional area of the molten mass at the outlet duct from each second zone has substantially a uniform temperature. Each zone is provided with temperature control means for both heating and cooling, such as burners and/or electrodes above and below the surface of the molten mass in the conditioner, and fluid jets and/or hollow ducts or panels engageable with the outside walls of the conditioner, so as to establish the desired uniform temperatures throughout the depth and width or cross-section of the molten mass flowing from each outlet duct of the conditioner and to minimize as much as possible convection currents in the conditioner.
摘要:
An apparatus and method is disclosed for cooling a molten stream of glass flowing in a firebrick hearth from an entrance end to an exit end of a glass furnace forehearth, the method comprising the steps of: cooling the bottom of the hearth which cools the molten glass by forcing air through ducts in the hearth bottom insulation; cooling each side of the hearth which cools the molten glass by forcing air through ducts along the side of the hearth.
摘要:
A forehearth through which molten glass flows is divided into a plurality of zones. Means are provided in each zone for measuring the temperature of the molten glass and the atmospheric temperature. Means are provided for accumulating and storing data. When the temperature of the molten glass in a selected zone is not within an acceptable range a control signal is generated. The control signal is in response to the current molten glass and atmospheric temperatures in the zone, the current molten glass temperature in the immediately preceding zone and the accumulated and stored data comprising the history of the molten glass and atmospheric temperatures for the selected zone.