US1909152A

US1909152A - Apparatus for feeding molten glass

Info

Publication number: US1909152A
Application number: US236025A
Authority: US
Inventors: Karl E Peiler
Original assignee: Hartford Empire Co
Current assignee: Hartford Empire Co
Priority date: 1920-03-31
Filing date: 1927-11-26
Publication date: 1933-05-16
Anticipated expiration: 1950-05-16

Description

May 16, 1933. K E; PE|LER 1,909,152

APPARATUS FOR FEEDING MOLTEN GLASS 8 Sheets-Sheet l Filed Nov. 25, 1927 MmmmA" INVENTOR.

' A A19/ef. H6/L E@ LAX/Mm A TTORNEY.

May 16, 1933. K. E. PEILER APPARATUS FOR FEEDING MOLTEN GLASS Filed Nov. 26 1927 8 Sheets-Sheet QQ NQ NNY May 16, 1933. K. E. PEILER APPARATUS FOR FEEDING MOLTEN GLASS Filed Nov. 26 1927 8 Sheets-Sheet 3 n un - May 16, 1933. K, E, PEIpER 1,909,152

APPARATUS FOR FEEDING MOLTEN GLASS Filed NOV. 26 1927 8 Sheets-Sheet 4 A T TOR/VE Y.

May 16, 1933. K. E. PEILER 1,909,152

APPARATUS FOR FEEDING MOLTEN GLASS Filed Nov. 26, 1927 8 Sheets-Sheet 5 maw Y K. E. PElLER 1,909,152

APPARATUS FOR FEEDING MOLTEN GLASS Filed Nov. 26, 1927 8 Sheets-Sheet 6 May 16, 1933.

May 16, 1933. K E PE|LER 1,909,152

APPARATUS FOR FEEDING MOLTEN GLASS Filed Nov. 26 1927 8 Sheets-Sheet 7 'Kif May 16, 1933. K, E PEILER 1,909,152

APPARATUS FOR FEEDING MOLTEN GLASS Filed Nov. 26 1927 8 Sheets-Sheet 8 v ATTORNEY.

' glass at the delivery of mold charges.

Patented May 16, 1,933

UNITED STATES PATENT oFFlcE KARL E. PEILER, OI WEST HARTFORD, CONNECTICUT, ASSIGNOB TO HARTFORD-EMPIRE COMPANY, 0F HARTFORD, CONNECTICUT, A CORPORATION OF DELAWARE APPARATUS FOR FEEDING MOLTEN GLASS Application iled November 26, 1921, Serial No. 236,025, and in Argentina Iaroh 3l, 1990.

My invention relates to the art of delivering or feeding molten glass from 'a glass melting furnace or other container to the molds of a shaping machine and it has special reference to the control of the temperature and viscosity of the glass while the lass is being transferred from the melting furnace or other container to the point of delivery or feed outlet.

More specifically, my invention relates to the construction and mode of operation of a forehearth for receiving the glass from the melting furnace or ot er container and delivering the glass to a discharge outlet or delivery point in the vproper condition to.

be fabricated into ware by an associated shaping machine.

In feeding molten lass from a tank furnace to shaping mac ines, it is now customary to flow the glass from the furnace into an auxiliary discharge chamber or forehearth extending from lthe furnace toward a delivery point Where suitable means are provided for forming and separating the point into a succession n order that the ware produced from these mold charges may be uniform in size and quality, the mold charges must be uniform as to their weight, shape, temperature and viscosity. Uniformity of weight and shape also depends in many feeders on uniform viscosity and temperature which is, therefore, doubl important. The viscosity depends part y on composition of the glass and partly on temperature, and hence proper temperature control is extremely important. Another requirement for proper quality and uniformity of lassware is thatthe mold charges from w ich the ware isvmade shall have the proper homogeneity. To secure proper homogeneity, all portions of the glass lapproaching the delivery point to form a mold charge must be as nearly the same viscosity and temperature as possible. This makes it important to be ablev to secure a uniform distribution of temperature and viscosity in the glass approaching the delivery pointl or feed outlet. The necessary uniformity ofthe mold charges cannot be produced without careful and accurate control of the temperature conditions in the forehearth since the large mass of glass in the melting furnace is subjected to many variations of temperature and viscosity, and such variations in the melting furnace cannot be economically avoided. Moreover, one furnace generally serves several feeders requiring different temperatures of glass.

The general object of' the invention is to provide a 'new and improved forehearth which will 'supply and deliver molten glass in the best form and condition for use in the associated shaping machine. A more specic object is to provide such a forehearth having improved means for controlling the temperature of the glass approaching the delivery point and particularly for insuring the uniform distribution of tempera ture and viscosity in this glass.

,Another object of my invention is to provide a forehearth wherein the temperature may be regulated and controlled independently of the temperature conditions in the melting furnace to which the forehearth is attached so that the desired conditions may be maintained in the forehearth in spite of various changes taking place in the draft, and temperature obtaining in the melting furnace.l y

Another object of my invention is to provide a forehearth -in which the distribution of temperature may be controlled at will so that different local effects may be secured to meet the operating conditions. More ically, it is the object to provide a forehearth of the character indicated havin means for controlling the distribution o flames or heated gases therein and particularly to control the direction of rojection or ilow of such flames or heate gases.

Another object of my invention is to provide a forehearth of the character indicated composed mainly of refractory material and enclosed in a substantially gas tight metal container which prevents undue leakage' of -air o r hot gases through the forehearth walls and enables temperature conditions in the forehearth to be accuratel controlled.

A still further object o my invention is specif-V to provide a forehearth for conditioning molten glass having refractory parts in contact with the molten glass and in contact with the heated interior of the forehearth and having heat insulation surrounding these refractory parts, the insulation being reinforced with elements of suiiicient strength to support the weight of the refractory parts and to hold the same in position.

A still further object of my invention is to provide in such a forehearth proper structural features for supporting and holding the forehearth in connection with a glass melting furnace and for permitting expansion and contraction and securing the desired ali nment of their parts.

mong various features of the invention for the accomplishment of these objects, and such other ob`ects as will appear, are the following. glass from the melting furnace to the discharge outlet or delivery point is provided with suitable means for controlling the temperature and condition of the glass discharged or delivered, independently of the temperature and conditions in the meltin furnace. This foreheartli is also constructed and arranged so as to permit free andindependent expansion and contraction of the glass furnace and of the forehearth parts, and to permit proper location and adjustment of the forehearth relative to the furnace.4 The forehearth is provided with improved heating means and is particularly adapted to deliver glass at the discharge outlet in a homogeneous condition.

This application is a continuation in part of my copending applications for Letters Patent, Serial No. 294,792, filed May 5, 1919, now Patent No. 1,655,391, method of and apparatus for feeding molten glass, and of my copending application for Letters Patent, Serial No. 683,576, filed Dec. 31, 1923, now Patent No. 1,760,254, apparatus for feeding molten glass.

In the accompanying drawings:

Figure 1 is a side elevation of the apparatus of my copending application, Serial No. 683,576, filed Dec. 31, 1923, showing the forehearth and part of the glass melting furnace and a mold to which the charges are delivered, some details being omitted;

Fig. 2 is a plan View in section approximately on the line 2-2 of Fig. 1;

Fig. 3 is a side elevation of the same a paratus in larger scalo and in section on t e longitudinal center line through the forehearth and part of the glass melting furnace, certain parts being omitted;

Fig. 4 is a plan view in section taken substantially on the line 4-4 of Fig. 3;

Fig. 5 is a front elevation in section substantially on the line 5-5 of Fig. 4;

Fig. 6 is a plan view in section substantially on the line 6-6 of Fig. 7;

A forehearth for conducting the- Fig. 7 is a side elevation of the same forehearth;

Fi 8 is a detailed view in side elevation showmg the open position of the stack damper;

Fig. 9 is a side sectional elevation similar to Fig. 3 but showing a different construction for heating the forehearth;

Fig. 10 is a side elevation of the apparatus of my co ending application, Serial No. 294,- 792, file May 5, 1919 shown partly in section alon1r the center line of the foreheartli with the shear mechanism omitted and showing the glass melting furnace and the forehearth; and

Fig. 11 is a front elevation taken partly in section along the line 11-11 of Fig. 10 of the center portion of the apparatus and shows the impeller outlet and shear carriers with the Vri ht hand shear in place and the left hand sear omitted.

The following is a copy7 of a portion of the s ecification of my copending application,

erial No. 683,576, filed Dec. 31, 1923 and describing the apparatus of Figs. 1 to 9, inelusive:

This embodiment of my invention com- )rises a forehearth connected to a glass meltmg tank or furnace and provided with a discharge outlet, together with mechanism for discharging the glass periodically, accumulating each discharge at the outlet to form it into a mold charge, and severing the charge.

The forehearth may include an extension 51 of the furnace walls by which it is connected to the furnace, and preferably comprises a separator or sealing block 52, a channel or conduit 53, and 'a bowl or discharge chamber 54, provided with suitable covers, casings, supports and temperature control means.,v `As shown in Fig. 3, the glass flows from the furnace 55 under the sealing block and into the forehearth by gravity.

One of the features of this invention comprises means for suitably supporting the forehearth and its glass conducting channel, so that it may be properly connected and aligned with the glass furnace, and yet be free to move with the furnace to permit the contraction and expansion of each. For this purpose the forehearth is preferably carried by a casing, comprising side walls 56 and 57 (Figs. 1, 5 and 6) and a bottom plate 58, which also permits suitable insulation of the forehearth. The inner end of the bottom plate 58 is connected with the steel bracing of the furnace, and ma be supported thereby. Itis supported at lts outer end by means such as a pair of iron shoes 61 (Figs. 1, 2 and 3) which are free to slide horizontally in any direction upon a cap 62 of the pier 63, as the furnace expands or contracts.

The supporting shoes 61 are also preferably arranged to permit the forehearth to be tilted longitudinally `upon the shoes, tov permit the adjustment of the inner end of the forehearth into conformity with the level of the adjacent end of the furnace, and to allow that inner end to follow changes of the furnace level caused either by expansion, contraction or settling of the furnace. The shoes 61 are preferably made with raised portions 59 which may be fixed or may bev adjustable jack screws, supporting the outer end of the bottom plate 58 by one of its transverse ribs 60 (Fig. 3), these raised portions acting as a pivot upon which 'the forehearth may tilt longitudinally as its inner end is raised orv lowered by the adjusting screws 71, or as it follows changes of the furnace level above referred to. B these means the forehearth may be adjuste to any desired level or position and the furnace and forehearth are free to expand or contract or settle independently without straining them or displacing the forehearth from glass flowino` connection with the furnace.

.z'lo prevent accidental longitudinal tilting of the forehearth during repair or construction work if it should become overbalanced by excess weight in front of the supporting shoes, holding-down means may be provided, such as tie rod 64 connected to a fixed anchorage beneath, and provided witha turn buckle 65 which may be adjusted to hold the forehearth in the desired osition.

The rear end of the orehearth is held `firmly against the furnace walls without exerting undue pressure thereon and may.'move with these 'walls when they are moved by expansion 01 contraction or settling of the furnace. To rovide vertical and horizontal adjustment o the rearv end of the forehearth to hold and align it relatively to the furnace, rear supports are provided, comprising angle irons 66 (Figs, 1 to 4, and 7) extending from the bottom plate 58 toward wall braces 67 of the furnace 55, each extension carrying a bracket 68 with a supporting screw 71 and a tie rod 72 (Figs. 3, 4 and 7). The supporting screws 71 rest on a bearing bar 73 which is bolted to the adjacent furnace iron work, such as the wall braces 67. The tie rods 72 pass loosely through holes in the brackets 68 and the bearing bar 73, and are adjusted by nuts 74 on either side of these members; whereby the forehearth may be moved toward or from the furnace, and into even contact therewith. Vhen the nuts 74 are adjusted, the tie rods act to swing the forehearth in any horizontal direction. By means of the screws 71, the rear end of the forehearth may be adjusted vertically. In this Way the forehearth may be connected to and held back against the furnace in the desired position and alignment without undue thrust on the abutting blocks of the furnace walls. As the furnace walls move under the influence of heat, the furnace iron work or wall braces 67 and the forehearth move with them as a unit.

against the front end of the channel 53 to hold it firmly against the extension 51. These straps also provide for inequalities inl the lengths of the channel` and casing structure. j

To provide spaces for suitable heatinsulation of the channel 53, it is carried on a series of refractor support blocks 76 and a bearing bar 77 (Iyigs. 3 and 7) and braced or held securelyin position sideways by a series of refractory brace blocks 78 and an le irons 81 (Figs. 2 and 7). This holds tie channel in the desired position and yet provides a space between the channel and the metal casing to hold heat insulating material 82, such as kieselguhr.

The brace blocks 78 fit betweennthe channel 53 and the casing 56 and 57, being supported in horizontal position by the ledges 83, (Fig. 5) and' they may be luted tightly in place with plastic clay or held with set screws, so as to bear firmly against the channel walls and brace them against the pressure of the molten glass. The channel may also be braced at its outer end by fire clay packing 84 (Fig. 6) packed between the channel and the side walls 56 and 57 of the casin Th support blocks 76 and the bearing bar 77 are preferably adjustable in height as by screws 85 (Figs. 3 and 5) threaded into or carried by the bottom plate 58, each block'7 6 having a metal plate 86 interposed between it and its adjusting screw. This construction enables the supports to be adapted to structural variations, such as inroo equalities in the channel 53, and enables the weight of the channel and parts carried" The channel 53 may be made in one piece of suitable refractor material and is preferably provided witi an outwardly turned flange 88 (Figs. 2 and 3) at its bac-k end, which fits against the extension 5l of the furnace and forms a joint of sufficient depth to prevent leakage of glass. The extension of the outer edges-of the flange beyond the insulation allows the. outer portion of the joint to be exposed to the air, thus chilling glass near the glass in the joint sufficiently to prevent leakage.

The channel is preferably made deep enough throughout the greater portion of its length to hold a body of glass of large cross section, so that it may flow slowly. The front end of the Hoor of the channel is inclined upwardly at 91 (Fig. 3) to provide a gradual reduction of the depth of the discharge bowl. This inclined portion 91 is also protected by insulating material which is retained in place by a metal apron 92, forming part of the enclos ing casing. of the forehearth.

At the outer end of the channel 53 and forming a shallower extension thereof is the discharge bowl 54 formed of suitable refractory material.- It is held by the metal cas ing 93 which is attached to the walls 56 and 57 of the main casing of the forehearth and which is made larger than the bowl to hold insulating material 82 between them, (Figs. 3 and 4). The glass flows from the furance through the channel 53. and into the discharge bowl, whence it discharges through a well and outlet under the control of regulating devices to be described later.

The forehearth is adapted to serve as a means for conditioning or re-conditioning -t-heglass as it flows through the forehearth from the furnace to the forehearth outlet, and is provided with suitable heating means and draft control means, which are operated and controlled independently of the varying conditions of draft, heat and homogeneity existing in the melting furnace, so as to deliver the glass at the forehearth outlet uniformly in a homogeneous condition and at the temperature desired for feeding the glass in mold charges of the desired weight and shape. The desired conditions are difficult, if not impossible to obtain or to control in the melting furnace itself, `because of the great mass of glass therein and the difficulty of heating that mass uniformly to the temperature desired for feeding the glass in compact charges of the desired weight, shape, temperature and uniformity. For this purpose the forehearth is provided with a firing or combustion space which is sealed off above the glass level from the fir ing or combustion space in the melting furnace, and is heated by suitable burners, from which flames are projected into the forward or delivering end of the forehearth and are then directed backwardly over the surface of the glass in the forehearth, the products of combustion passing out through a draft stack located over the rearward end of the forehearth. For convenience in thus controlling and directing the heat, the firing space is preferably divided into two chambers (Fig. 3), a front chamber 89 at the dischar e end, and a rear chamber 90 toward the urnace end of the forehearth, these chambers being partly separated by a baille formed by the

blocks

102, 103, 104, extending downwardly toward the surface of the glass, so as to defleet the flames or heated currents close to the surface of the glass as they pass backwardly under the baille. The forehearth walls enclosing the fire space and glass are made of refractory material and are as far as possible provided on their outer sides with heat insulating material, enclosed and retained by suitable metallic casings.

The front chamber 89 is enclosed by an arched front cover 94, (Figs. 3 and 9) a pair of mating side covers 95 each forming a half arch, and a sloping cover block 96 rest-- ing on side walls. The front cover 94 and the side covers 95 are cut away as shown, (Fi s. 3 and 9) to form a circular opening 97 tirough which the

discharge controlling members

146 and 172 operate, and are readily removable without disturbing these members.

Behind the front chamber 89 is a baffle formed of

refractory blocks

100, 101, 102 103 and 104 (Figs. 3 and 5) bridged across rom the side walls of the channel 53. The upper block 101 is provided with an opening 105--aI into which a suitable burner 105 (Fig. 3) discharges a controllable mixture of gas and air into a port 106 formed in the block 102. This port is preferably horse shoe shaped as shown in Fig'. 4, whereby the burning mixture is discharged into the forehearth in a divided stream. To prevent the fuel mixture from igniting prematurely in the port 106, the port block 102 is kept relatively cool b heat insulation 107 supported by the blocfi- 103 and retained in place by the refractory blocks 104.

The rear chamber 90 back of the baffle is enclosed by side walls 108 and a rear wall 109 carrying a cover block 111. A sealing block 52 extending into the glass seals the chambers 89 and 90 from the fire spaces above the glass level in the furnace. Each side wall 108 is provided with a port 112 for admitting cooling air to aid in conditioning the glass when desired, and the cover block 111 is provided with an opening 110 leading to a suitable exhauststack 113.

A modified arrangement, more particularly of the burner and to some extent also of the burner and fire spaces, is shown in Fig. 9. Here the fuel space is extended above the forehearth, the extension with its insulating means being more readily removable and renewable. Above the forehearth and forming an extension of the combustion or mixin chamber in the forehearth is an inverte refractory bowl 121, provided with a burner opening 122 into which any suitable form of gas or oil burner may discharge. For purposes of this illustration, an adjustable gas burner 123 of the induction type is shown. The inverted bowl 121 is surrounded by metallic casing 124, provided with heat insulation 125, and enclos-v ing an `annular air space 126 between the casing and the bowl. Air drawn into the annular air space 1.26 by inductive action of the burner enters all around the open lowery edge of the` casing 126, is preheated by its passageover the heated bowl 121, and is then injected through ythe opening 122 into thebowl chamber. The casing 124 `is centered with the bowl 121 by means of ad'ustable pins or screws 119 disposed aroun the side wail of the casing and bearing against the bowl, so as to equalize the width of the annular space and distribute the conse uent inflow of air equally on all sides. Thlsresults in conservation of the heat, which instead of being lostby radiation to the surrounding air is confined by the insulated .casing 124 and is moreover taken up b the -entering air and returned to theinsi e of the bowl, the heated air also improving the e combustion conditions.V

From the bowl 121 the space extends through ports 118. formed in the burner block 116 and in a dividing block 117, which divides the passage for the burning gases intoports o the desired number and havingthe desired size and distribution, as in Fig. 3. The blocks 116 and 117 in this case form a baille similar in effect to that shown in Fig. 3, `dividing the firing space into two chambers. In the construction shown in Fig. 9, the cover in front of the baie is made in separate pieces 114 and 115, one or both of which may be removed to allow of inserting a gate to stop the flow of glass from the forehearth While the discharge bowl is being replaced. This, however, is a feature whichy may also be applied to the construction shown in Fig. 3 by suitable design.`

In both of the constructions shown, the temperature conditions in the forehearth may be controlled independently of the temperature conditions in the melting furnace, to properly condition or re-condition the glass. The spaces in the forehearth and in the; melting tank above the glass line are separated from' each other to prevent the flow ofl air and gases between the furnace and the forehearth above the glass line, so that the fire spaces in the forehearth are not affected by the draft or temperature conditions in the furnace, thus permitting independent control of the heating conditionsin the forehearth. l

The rear wall 109 (Fig. 3) of the forehearth serves as a partial separating member, which may be supplemented by a separator or sealing block 52 extending below the glass level (Fig. 3). This block bridges across the furnace extension 51 and fits into recesses 127 (Fig. 2) formed in the side walls of this extension, fitting a ainst Ythe rear end of the channel 53 an the rear wall 109 of the forehearth. To further complete. the seal, the yjoint'between the rear wall and the sealing block may be sealed by a fire clay luting. The depth to which the separator block 52 is immersed in the glass may be varied as desired to draw glass from the furnace into the forehearth from a higher or lower stratum. Since the temperature of the glass in the furnace is hottest at the top and is progressively cooler toward the bottom, the depth to which the separator 52 is set permits hotter or colder glass to be drawn from the furnace as desired.

The extension 51 from the furnace may be partly or fully covered by covers 128, some of which may be removable, to facilitate replacing or adjusting the separator 52. It may at times also be desirable to remove a section or'sections of the cover 128 in order to cool the glass iiowing from the melting furnace into the body of the forehearth.

The stack 113 connected with the opening y110 in the cover block 111, may consist of a metallic casing lined with suitable refractory material. At the upper end of the stack is a refractory damper 131 (Figs. 1, 7 and 8) carried in a frame formed by angle irons 132 pivotally mounted on a rod 133, so that the damper may be tilted by bars'134 connected with an operating rod 135. The lower end of the rod passes through a fixed bracket on the forehearth casin and is threaded for a hand nut 136, whic is held against the bracket by the weight of the damper. By turnin this hand nut 136, the damper may be a justed to control the amount of draft applied to the fire spaces in the forehearth by the stack.

In order to secure a better control of the draft conditions in the forehearth, the metallic casing enclosing the forehearth and the structure of the refractory parts and their braces is adapted to form a tight closure. Such parts as the sealing block 52 and certain of the cover blocks are arranged to make close joints and adapted to be luted with fire clay. The opening 97 fits the discharge control means closely, so that uncontrolled leakage between the lire space and the outside air is reduced to a minimum.

The air ports 112 foradmitting cooling air to the rear lire space when desired are also provided with close fitting closures to minimize leakage. Refractory thimbles 138 (Figs. 4 and 5) abut against the refractory side walls 108 in register with the port openings 112 therein and extend through the insulation 82 and the side of the upper forehearth casing 139. A collar 140 carried by the casing fits closely against the end of the refractory thimble and holds it in place against the side wall. The joint between the collarand the thimble and betwee-n'the thimble and the side wall is preferably tight. The collar 140 carries a swinging door 141 pivoted thereon and carrying a transparent window 142 made of mica or heat resisting glass. The door is ada ted to fit closely against its supporting col ar 140 when closed, and may be opene to any desired extent by screw 143 threaded into the door and bearing against the collar. By thus adjusting the door opening, the desired amount of cooling air may be admitted into the foreliearth or it may be positively shut off. The transparent window has the great advantage ofpermitting a view of the interior of the lire space, as for inspecting the re conditions, without such interference therewith as would be caused by opening the door for such inspection. If the door were opened for this purpose, the increased amount of air admitted would so'alter the draft and firing condition as to give an incorrect indication of the conditions existing when the door is properly adjusted.

B means of combination of the heating liurner, controllable stack draft, controllable admission .of cooling air, and the general arrangement for-firing, the glass delivered by the forehearth may be properly vconditioned and kept uniformly at the desired temperature in spite of variations of temperature occurring in the glass furnace. The burner projects a divided flame forward toward the discharge end of the forehearth, so that the flame impinges against and flows along the cover blocks, then turns downwardly and flows back along the surface of the glass toward the rear of the forehearth under the baille plate 103, as indicated by the arrows in Fig. 3. The burner may be regulated by suitable valves to control .the amount of fuel and air admitted. Depending on the setting of the burner and the draft conditions, the llame or heat therefrom will be projected toward the front end of the forehearth a determinable distance, either deflecting downwardly against the front cover 94 and around the tube 146, or turning downwardly to assume its backward course at a point nearer the burner ports 106. Some of the llame may turn downwardly closer to the burner nozzle, and other portions may be projected further forward, so that a horse-shoe flame is produced, which gives an extremely even heatingefect in the front end `of the forehearth.

This tends to bring the glass around the flow outlet to an even temperature and helps to produce a homogeneous mold charge. As the flame travels backwardly under the baille, and spreads throughout the greater s ace 90 back of the baille; its temperature alls progressively, so that the glass is subjected to a gradually increasing heat effect, as it progresses from the rear to the front of the forehearth. This is advantageous, as will be explained later.

The temperature of the rear fire space 90,

which is naturally lower than that of the front fire space 89, may be further controlled by the regulated admission of cooling air through t e ports 112. This air cools the hot or burning gases coming from the front fire space, and escapes u the stack with them. The amount of coo ng air admitted depends not only on the adjustment of the air port doors, but also on the setting of the stack damper, which controls the draft 1n: ducing the supply of cold air.

The adjustments of the stack damper 131 also inluences the course and position of the flame from the heating burner. With any given burner adjustment, an increase of draft by raising the stack damper causes the flame to turn downward and backward nearer to the baille and tends to increase the temperature of the rear ire space 90. Conversely a decrease of draft by lowering the stack damper throws the burner flame further forward and tends to lower the temperature of the rear fire space 90. If, for any setting of the stack damper, the burner be adjusted to deliver more fire or for more fuel relatively tothe air supply, the flame will be thrown further forward, and if it be turned down to deliver less'fire or to burn less fuel in proportion to the air, the flame will not be thrown so far forward, but will turn down and move backwardly under the baille sooner than it would'if more fuel is supplied. The effect of the stack draft on the flame in the front fire space 89 is varied by the degree of opening of the' cooling air orts. If, with any given setting of stack amper, the cooling ports are opened wider, the burner flame will be thrown further forward. In other words, the effect of thestack 'draft in pulling the fire further back or letting it go further forward depends on the amount of air which is admitted by the cooling air ports to satisfythis draft, and on the amount of fuel projected by the burner to satisfy the draft.

The character of the flame delivered by the burner is important. The llame should not be too short or quick burning as this produces only a local heat with resultant uneven temperature in the glass. There should, however, always be enough air for complete combustion and to prevent a smoky flame, which is not so easily controlled and tends to de osit carbon in the glass. The character o the llame may be varied within limits so as to produce a longer or shorter flame. It is preferable to adjust the burner to produce a clear flame which is neither smoky nor short and quick burning, and which allows a maximum of control by the stack damper and produces an even heating effect, especially in the front ire space 89 of the forehearth, when the glass is nearing the completion of its progressive conditioning treatment. Such lll.)

a flame may easily be drawn back or allowed to burn further forwardin the forehearth by respectively raising or lowering the stack damper.

By adjusting these various factors, the temperature of the glass bein delivered may be raised or lowered from t e temperature ofthe glass in the furnace. This may be done within a certain range by adjustment of the burnerI alone. If, however, the glass in the furnace is too hot as it flows into the forehearth, it may be cooled by admission of coolin air through the cooling ports. In doing t is, it (is preferable to cool the surface of the Glass slightly below the temperature at whic it is desired to deliver it, so that then when the glass is subjected to the action of the flame in the front fire space, it will attain the desired temperature and be uniform throughout. If the glass from the furnace is too cold, the burner may be adjustedto supply more heat and the flame may, if necessary, be drawn well back into the rear lire space 90 so as to extend its heating effect over the entire length of the forehearth.

The glass flowing from the furnace and through the forehearth tends to be hotterV on top and' progressively colder toward the bottom. It also tends to be colder at the sides of the forehearth than at the center line. This is because of the temperature variation between upper and lower layers in the furnace and because of the coolingl influence of the bottom and side walls of the forehearth. The insulation82 helps to minimize this influence and so to minimize cold streaks in the glass. The double fire space with the even heat in front also helps to equalize the temperature of the glass in the relatively shallow layer flowing from the front of the channel into the discharge bowl 54 and permits the delivery of homogeneous mold charges therefrom.

That embodiment of my invention shown by Figs. and 1l is described bythe following portion of the specification of my copending application, Serial N o. 294,792, filed May 5, 1919.

The invention is herein shown embodied in a machine having the necessary mechanical movements and adjustments, and cooperating with a conduit projecting from a glass furnace, from which the molten glass is thus delivered in mold charges to an assoociated molding or shaping machine.

The molten glass flows from the glass furnace 1 through a channel or conduit 2 (Fig. 10) to an outlet 3. It is there acted upon by an impeller 13 mounted for vertical movement, and 'provided with various adjustments. As it issues periodically in regular cycles from the outlet, it forms successive gathers from which mold charges are severed by shear blades .4 reciprocating below the outlet. The separated mold charges fall upon a moistened chute 5 andslide upon it to 4the molds mounted on the table of the associated shaping machine.

The channel 2 is made of refractory material surrounded on the bottom and sides by heat insulation 11. At the outer end of the channel is an outlet spout 12, the interior of which is shaped so as to coact with the impeller 13. This spout is held in an iron frame or case 14, which also serves as a retainer for the insulation 11, the spout being surrounded with insulation, except at the outlet 3.

The bed 15 is carried by the same foundation which supports the base of the machine. It rserves to support the channel 2 by means of intermediate refractory supports 10 and carries two brackets 16 clamped thereto by screws and which support the spout case 14. The brackets also carry set screws 18 which bear against projections on the spout caseand holdthe spout against the end of the channel. These screws may be adjusted to allow for expansion and contraction of the channel and spout. The-brackets also carry removable drip pans 20 for receiving the cooling water dripping from the shear -blades 4 and from the sprays 21.

Over the spout is a cover 22 of refractory material carried in a metal case 23 which also serves as a retainer for heat insulation l1, the metal plate 24 serving to keep the insulation in place. The plate 24 and cover 22 have openings through which the impeller projects. Back of this cover and over the channel is another' refractory cover 25 formed so as to retain heat insulation 11 which is covered by a metal plate 26 to keep it in place.

The channel and spout are heated by suitable means, such as a gas burner 27, which projects through the side lwall block 30. This burner is provided with air and gas valves 31 for regulating the llame, which partly fills the space over the molten glass. The products of combustion are carried-oli' by the fire brick stack 32 carriedon refractory lintels 33, which bridge the channel and are separated at their ends by refractory blocks. At the upper end of the stack is a damper 34 carried on a pivot 35 and adjust` able through an arm 36, and connecting rod 37 having a handle at its outer end and provided with notches 38 engaging with a stop 40, thus allowing the damper to be set at any desired opening. By'appropriately adjusting the burner and damper the proper temperature may be maintained in and over the channel and spout. The insulation acts to conserve the heat, and the radiation from the rear .assists in heating the outlet end, thustendin to maintain a uniform temperature througout.

the right-hand gate arm 43, thus allowing the position of the gate to be adjusted by turning the hand wheel 50. The Glass surface in the furnace 1 is preferably maintained at a higher level than that desired in the spout 12 and the level or head desired in the spout may be maintained by adjustment of the gate.

In operation, the gate 41 is raised to the proper point to maintain the desired head of glass over thel outlet andthe machine is set in motion, reciprocating the impeller and the shears. The molten glass issues from the outlet under the' combined influence of gravity and the action of the impeller, which times and controls its accumulation in gathers which are successively suspended from 'the outlet ring and from the impeller end. For each complete reciprocation of the impeller there is a reciprocation of the shears which severs a mold charge from each suspended gather. After each severing operation the freshly cut end or stub remaining below the outlet, and forming the lower end of the succeeding gather, is moved upwardly, or its downward movement is retarded, by the action of the irnpeller.`

The relation of the diameter of the gather to the outlet size depends partly on the speed of the machine and the viscosity of theglass, as these influence. the elongation and consequent reduction in diameter of the glass column issuing from the outlet.

The embodiments shown and described herein are only several of many possible embodiments of the invention. It should be understood that the various features of the invention may be modified both in structure, combination and arrangement to adapt` l ,the invention Ato different uses or different conditions of service. lVhile the fore hearths herein shown are particularly adapt-` ed to discharge the molten glass through a feed outlet, yet they may .also be employed for delivering glass in proper condition to a gathering point for use with suction gathering apparatus, such as that shown in the copending application of Peiler and Barker, Serial No. 218,398, filed Sept. 9, 1927, or such as that shown in my copending application Serial No. 24,789, filed April 21, 1925, now Patent No. 1,785,209.

1. Apparatus for feeding molten glass having .in combination, a forehearth, a bridge member above the glass in the forehearth, a burner above the bridge member,

and heat insulating material between the bridge member and the burner.

2. A forehearth Connected with a lass melting furnace and 'comprising a re ractory container for molten glass, an outer metallic casing spaced from the container, rigid refractory struts interposed between the casing and the container, and heat insulation filling the space around the struts.

` 3. A forehearth connected with a glass melting furnace and comprising a refractory container for molten glass, a casing spaced from the container, supporting struts resting on the casing underneath the container to support the container, side`braces interposed between the container and casing to hold the container against horizontal movement with respect to the casing, and heat insulation in the space between the container and the casing.

4. A forehearth connected with a glass melting furnace and comprising a refractory container for molten glass, a supporting casing spaced from the container, a plurality of independently adjustable vertical supports for the container carried by the casing, and heat insulation in the space between the container and the casing.

5. A forehearth connected with a glass melting furnace and comprising an outer support, a plurality of vertically adjustable struts supported by the support, a refractory container for the glass supported by the struts, and heat insulation around the struts between the container and the support.

6.A forehearthcomprising a refractory container for molten glass, a casing around the container, and means for adjusting the container with relation to the casing;

7. A forehearth comprising a re actory container for molten glass, a casing around but 4spaced from the container, insulating material between the casing and the container, and means for adjusting the relative position of the casing and the container.

` 8. A forehearth comprising a refractory container for molten glass, a casing around the container, and means on the outside of the casing for adjusting the position of the container relative to the casing.

9. A forehearth comprising a container for molten glass connected to a glass melting furnace and adapted to be raised, lowered, and tilted, and a Vplurality' of independently verticallyadjustable supporting means for raising, lowering, or tilting the container. i

eol

10. A forehearth connected with a vglass melting furnace,. comprising a refractory container for molten glass, a casing for the container, means for adjusting the casing with relation to the furnace, and means for adjusting the container. with relation to the casing.

11. A forehearth for glass furnaces, comprising means for vertically adjusting the end adjacent the furnace, a bearing block supporting the projecting end, and having a pivotal connection with the forehearth, and a supporting member having a plane surface upon which the bearing block rests, whereby the block is free to move with the forehearth under the influence of heat.

12. The combination with a glass melting furnace provided with wall braces, of a fore-v hearth projecting from the furnace and comprising a refractory container for the glass and an outer casing, rigid connections betweenfthe casing and the Wall braces, said l5 connections being adjustable in length to secure the desired relation between the furnace Walls and the refractory container, whereby motion of the furnace is communicated to the forehearth through the wall braces and casing. l

13. In apparatus for discharging glass from a melting tank, a forehearth having a discharge outlet adjacent to its outer end to which the glass flows from the tank,

means for supplying a divided stream of a combustible mixture to the space above the glass rearwardly of the' discharge outlet and for projecting the divisions of such stream forwardly at opposite sides of said forehearth space, and an exhaust stack communieating with the space above the glass in the forehearth rearwardly of said combustible mixture supply means.

14. In apparatus for discharging glass from a melting tank, a forehearth having adischarge outlet adjacent to its outer end to which the glass flows from the tank, a

transverse baiile bridging the forehearth above the glass level rearwardly of the discharge outlet, a'substantially U-shaped passage in said bafiie opening at its ends at y the front of the bale at opposite sides of the longitudinal median line of the forehearth, means for projecting a combustible mixture through the end portions of said passage into the space above the glass at the front of the baille and toward the front wall of the forehearth, and an exhaust stack communicating with the forehearth rear- 50 wardly of said baflie.

15. A forehearth connected with a glass melting tank Vand comprising a refractory container for molten glass, a casing outside of the container and adjustably spaced therefrom, and heat insulation in the space between the container and the casing and held in place thereby.

Signed at Hartford, Connecticut, this 22nd' day of November, 1927.

60 KARL E. PEILER.