Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
  • C03B5/04—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in tank furnaces
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
  • C03B5/02—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating
  • C03B5/025—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating by arc discharge or plasma heating
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
  • C03B5/02—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating
  • C03B5/027—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating by passing an electric current between electrodes immersed in the glass bath, i.e. by direct resistance heating
  • C03B5/0275—Shaft furnaces
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
  • C03B5/12—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in shaft furnaces
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
  • C03B5/16—Special features of the melting process; Auxiliary means specially adapted for glass-melting furnaces
  • C03B5/235—Heating the glass
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping

Definitions

• This invention relates to the manufacture of glass articles, particularly the manufacture of glass containers, though it is applicable to the manufacture of other articles, for example glass bricks or fibreglass.
• Very substantial quantities of glass are used for the manufacture of glass containers, principally bottles and jars. Such manufacture is conventionally carried on in manufacturing plants of very substantial size in which glass is manufactured from its basic ingredients. Usually so-called batch is formed by mixing sand, limestone, soda ash and optionally other ingredients and this batch is then fed in to one end of a large furnace.
• the furnace is usually a gas or oil fired type, or an electric furnace with gas or oil firing to start it up, and the batch ingredients are heated at the inlet end of the furnace to a temperature at which they fuse to form a glass.
• Submerged electrodes may be used to provide heating or further heating.
• This glass then moves slowly down the length of the furnace to one or more sections of the furnace from which molten glass may be extracted. These are generally called forehearths and each will consist of a refractory lined basin having set in its floor one or more apertures through which molten glass may feed. Below those apertures, appropriate feed mechanisms to
• OMP control the flow may be located, those mechanisms conventionally producing so-called gobs of molten glass which are fed automatically into container manufacturing machines which are located adjacent each forehearth.
• Some economies in operation are conventionally achieved by using, as part of the batch material for making the glass, broken glass, so-called cullet.
• the presence of cullet in the batch assists in the melting and formation of glass from its ingredients and effectively recycles already formed glass, so reducing the overall energy costs.
• the supply of cullet over recent years has substantially increased as a result of bottle recycling schemes designed to reduce overall energy consumption in the glass making industry and accordingly to reduce the cost of imported oil, but this has made no major difference to the way in which glass containers are conventionally made.
• the present invention provides a method of making glass articles comprising: a. introducing particulate glass into a molten glass containing vessel and simultaneously heating the particles of glass to melt and fuse them, b. passing molten glass from the vessel to a conditioning chamber having one or more outlets, c. adjusting the temperature of the glass at or near the outlet(s) to a desired temperature, and d. withdrawing molten glass from the one or more outlets of the conditioning chamber and forming glass articles therefrom.
• the particulate glass is heated by means of a plasma heating system.
• a plasma heating system provides a very efficient way of heating the particulate glass as it is introduced and, if used in the so-called transferred arc mode, it can additionally provide heating to the body of molten glass in the vessel.
• the initial heating vessel and the conditioning chamber may be combined as a single vessel, e.g. divided into two chambers by a weir under which molten glass passes, or they may be separate with an outlet from an initial heating vessel feeding an inlet to a conditioning vessel.
• the heating vessel is located above the conditioning chamber and particulate glass is fed into the heating vessel likewise from above.
• An arrangement of particular and preferred value is to employ a unitary vessel having an upper heating part and a lower conditioning part. In such a case, a number of streams of particulate material may be fed into the top of the upper part where they intersect a plasma.
• it is desirable to rotate the plasma e.g. by sweeping out a cone-shaped area at suitable speed.
• the temperature of the molten glass may be controlled by passing an electric current through it.
• a plurality of electrodes of suitable construction may be made e.g. of graphite, molybdenum or other material known for the purpose.
• the current passed through the glass to maintain it at the desired temperature may be controlled in known fashion and both the heating vessel and the conditioning chamber may be provided with suitable control and monitoring apparatus, for example thermo-couples or pyro etric apparatus to enable control to be exercised adequately.
• suitable control and monitoring apparatus for example thermo-couples or pyro etric apparatus to enable control to be exercised adequately.
• OMP gas firing may be employed to adjust the temperature.
• suitable level controls may be provided to maintain the desired quantity of glass in the vessel and chamber.
• This may take the form of a direct level sensor of some appropriate construction or, for example, the amount of molten glass in the l vessel or chamber may be monitored by weighing the vessel or chamber and its contents e.g. by mounting it on a plurality of load cells.
• the invention is illustrated by way of example in the accompanying drawings which show two ways of putting it into practice.
• Figure 1 is a diagrammatic view of a simplified system including melting and conditioning chambers, and
• Figure 2 is a diagrammatic view of an alternative embodiment.
• Figure 1 shows an arrangement in which cullet is fed from a feed hopper 1 through a suitable feed line or lines 2 to an injection mechanism 3. This projects pieces of cullet onto the surface of a melting zone 4 at one end of a refractory lined or water cooled unit 5.
• a plasma torch 6 is arranged to create an ultra high temperature region between itself and the melting zone 4 at one end of the unit 5, through which region the pieces of cullet pass.
• the melting glass at the end of the unit is fed directly by the current which passes through the plasma and then through the molten glass to be collected via a suitable electrode 14 which is set into the base of the melting zone 4.
• Unit 5 consists of a generally elongate enclosure having walls 10, a base 11 and a roof 12.
• a vertical partition 13 depends substantially vertically from roof 12 but does not reach the base 11. Partition 13 divides unit 5 into melting zone 4 and a refining zone 7.
• the temperature of the glass is accurately controlled using sensors of known type (not shown) and burners or coolers (depending upon whether cooling gas is blown through them or whether a combustible and ignited mixture of gas and air is blown through them) 16.
• the refining zone 7 can be heated electrically, either by resistance elements or by Joule effect heating.
• FIG. 1 shows in cut-away view a furnace for use in carrying out the present invention.
• the furnace is generally cylindrical consisting of an outer framework 20 lined with a cylindrical refractory lining 21.
• the base of the furnace shown is generally conical (though a flat base could be used) and likewise lined with refractory slabs.
• Set in the middle of the conical base is an orifice block 25 and a suitable orifice closure mechanism 26 of known type is located below block 25.
• a shrouded lid generally indicated at 30 and consisting of a central ceiling formed of refractory 32 having a central aperture 33 and a plurality of feed apertures 34 in the form of a square array.
• a depending skirt 35 which fits round the exterior of the main furnace body. Skirt 35 constitutes an annular extraction duct to remo w st ⁇ gas? 1 ? from the furnace chamber via pipes 36 (onl one of which is shown).
• various heating means are provided.
• a plasma torch 40 is mounted in a mechanism 42 which can be controlled to move the plasma torch so that the plasma issuing from its base, indicated at lines 44, may be directed i.e. the direction of the emitted plasma from the torch may be caused to sweep in a generally conical shape around the interior of the furnace.
• the torch is shown raised from the lid 32, though in use it is located with its lower end below the ceiling 32.
• molybdenum electrodes 46 set into the base of the furnace and connected by means of high current leads 47 so that they may be used in conjunction with the plasma torch to heat molten glass in the furnace by Joule effect heating.
• a plurality of gas burners may be installed in the furnace to assist in starting it up.
• the nozzle block 25 may have an integral electrical heater in it enabling fine control of the temperature of molten glass as it leaves the furnace.
• the furnace is supported by a plurality of spaced pillars 50, of which two are visible, each pillar resting on a load cell 51 in turn supported on a metal framework 52.
• appropriate electrical control gear both for operating the plasma torch and molybdenum electrodes and for monitoring the weight of the whole unit by detecting signals from load cells 51 and carrying out appropriate calculations.
• appropriate electrical control gear is provided to enable the plasma torch to be rotated by mechanism 42 at a suitable rate, and to enable operation of the outlet gate mechanism 26.
• streams of particulate material are fed using appropriate handling equipment through orifices 34 to intersect the rotating beam from plasma torch 40.
• the particles are heated very substantially as they pass through the plasma and come to rest on a bath of molten glass which accumulates at the bottom of the furnace and which is kept molten by the passage of electrical current through the mass of molten glass, which current is led away via electrodes 46.
• the electrical control means may ensure that the ease with which current is fed through electrodes 46 may depend on the momentary position of the plasma torch.
• the level of molten glass in the furnace may be kept constant by appropriate controls, e.g. by ensuring that the feed of cullet is dependent on suitably processed signals received from the load cells.
• Molten glass fed through the orifice block 25 may be led e.g. to a refining chamber or vessel, hence molten glass may be formed into gobs for feeding to an independent section container-forming machine.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Furnace Details (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10547105

Family Applications (1)

Country Status (5)

Cited By (2)

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Family Cites Families (7)

• 1983
  • 1983-08-10 GB GB838321525A patent/GB8321525D0/en active Pending
• 1984
  • 1984-08-09 ZA ZA846163A patent/ZA846163B/xx unknown
  • 1984-08-09 IT IT48709/84A patent/IT1178401B/it active
  • 1984-08-10 WO PCT/GB1984/000278 patent/WO1985000801A1/en unknown
  • 1984-08-10 EP EP84903072A patent/EP0152444A1/en not_active Withdrawn

Non-Patent Citations (1)

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