US1783208A

US1783208A - Glassware-annealing leer

Info

Publication number: US1783208A
Application number: US129373A
Authority: US
Inventors: Percy Q Williams
Original assignee: Owens Illinois Glass Co
Current assignee: OI Glass Inc
Priority date: 1926-08-16
Filing date: 1926-08-16
Publication date: 1930-12-02
Anticipated expiration: 1947-12-02

Description

Dec. 2, 1930. P. Q. WILLIAMS GLASSWARE ANNEALING LEER Filed Aug. 16, 1926 7 Sheets-Sheet 1 INYENT in.

Dec. 2, 1930. P. Q. WILLIAMS GLA-SSWARE ANNEALING LEER 1926 7 Sheets-Sheet 2- Filed Aug. 16

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IN'SZENT UR Z/i-raPn/ K Dec. 2, 1930. P. Q. WILLIAMS I GLASSWARE ANNEALING LEER Filed Aug.. 16, 1926 '7 Sheets-Sheet 6 Patented Dec. 2, 1930 UNITED STATES PATENT OFFICE PERCY Q. WILLIAMS, 0] TOLEDO, OHIO, ASSIGNOR TO OWENS-ILLINOIS GLASS COM- IPANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO GLa'sSWARE-ANN'EALING LEER Application filed August 16, 1926. Serial No. 129,373.

This invention relates to improvements in leers for annealing bottles and the like glassware and relates particularly to that type in which the ware is conveyed through an annealing tunnel by an endless conveyor.

In Patent Number 1,773,383, granted in my name August 19, 1930, Glass annealing leers, is disclosed and claimed the feature of directing and regulating the flow of an annealing medium through a passageway immediately beneath and extending lengthwise of the leer conveyor, said feature being to some extent shown, but not claimed herein.

An object of the present invention is to provide means whereby the heating zone of an annealing chamber may be maintained at a uniformly high temperature of the desired degree by continuous circulation therethrough of atmospheric air which has been preheated and which is withdrawn from the heating zone and returned to the heating unit.

Another object is to provide means whereby heat rising from ware and brought into the annealing chamber with the ware may be utilized in assisting a recuperator in the maintenance of proper temperature in atmospheric air employed in heating a predetermined zone of the annealing chamber or tunnel.

A further object is to provide means eliminating direct cont-act between the ware and products of combustion and thereby avoid the formation of a film upon the surface of the wine or otherwise marring its appearance. Elimination of the mixture of products of combustion with the medium employed in heating the ware, also materially reduces the density of this medium and avoids the necessity of using a high powered blower in the creation of circulation of the medium.

A still further object is to provide means a recuperator whose effective heating capacity may be readily varied; and to equip the leer with a series of longitudinally spaced suction boxes throughany one of which air may be drawn from a predetermined heating zone and returned to the recuperator, thereby providing eifective means for attaining a high or low annealing curve whose length may be varied to meet the particular requirements of the ware being treated.

A further object is to provide means whereby drafts of cold air entering either end of the leer tunnel, will be quickly removed from the tunnel without injuring the ware being annealed.

Other objects will be apparent hereinafter.

In the accompanying drawings:

Figure 1 is a top plan viewof the assembled leer, the upper and lower sections of this view showing, respectively, the forward half and the rear half of the leer.

Figure 2 is a side elevation of the leer shown in Fig. 1.

Figure 3 is a central vertical longitudinal sectional view of the feeding end.

Figure 4 is a horizontal sectional View taken substantially on the line IV-IV of Figure 3.

Figure 5 is a vertical sectional view of the intermediate portion of the leer adjoining that shown in Figure 3.

Figure 6 is a'horizontal sectional view showing the means employed for causing re circulation of air through the heating unit and annealing chamber.

Figure 7 is a vertical sectional view taken on the line VIIVII of Figure 1, showing means for trapping and exhausting cold drafts entering the rear end of the tunnel.

Figure 8 is a transverse sectional view taken substantially on the line VIII-VIII of Figure 1.

Figure 9 is a transverse section taken substantially on the line IXIX of Figure 3. Figure 10 is a transverse section taken substantially on the line XX of Figure 5. The leer shown in the drawings includes a pair of longitudinally extending base members 15 resting upon and interconnected at spaced points by transverse tie bars or other means (not shown). Preferably, these base members 15 consist of upwardly opening channel bar sections whose abutting ends are suitably interconnected. A set of bars 17 is spaced above these channel irons (Figs. 9 and 10) and extend transversely thereof, providing means for supporting a longitudinal track-.

Way 19 including sets of transversely spaced rollers 18 over which an endless ware conveyor"Cruns, during its movementthrough the tunnel or annealing chamber of the leer. The tie bars interconnecting the base members also support a series of rollers 21 upon which the lower or returning reach of the ware conveyor rides, thereby preventing contact of said portion of the conveyor with an insulating material 22 which forms the bottom of the leer and fills the space between the bars mounting the sets of rollers.

The side walls 23 of the leer preferably include fire brick supported in the longitudinal channel bar base members, faced with an insulating material 24, said walls being enclosed by a sheet metal casing 25. A major portion of the tunnel or annealing chamber ceiling 26 is formed of an insulating material held in its proper relation by any preferred means, said ceiling decreasing in thickness toward the discharge end of the tunnel to permit gradual reduction of the ware temperature.

The leer is provided at longitudinally spaced points with sets of transversely spaced outlets 27 (Figs. 5 and 10) in its ceil ing, providing communication between the interior of the annealing tunnel or chamber, and a transverse passageway 28 formed entirely within its ceiling and communicating at its opposite ends with the pending branch passageways 29 in the leer side walls and having closed lower ends. These passageways which form portions of suction boxes B are provided by constructing from angle-iron or other material, a transverse box-like unit which is embedded in the insulating material forming the ceiling, said box-likeunit having its ends opening into similarly formed vertical units 31 whose lower ends are rigidly fixed to the aforementioned channel bar base members 15. The transversely disposed box-like unit is provided with the set of outlets 27 referred to, such outlets being closable fully or in part by means of a slide valve 32. This slide valve, as shown, may be formed of channel iron whose web portion is provided with openings 33 corresponding in number to the outlet openings in the top unit and adapted to have sliding engagement with the upper side of the angle-iron section in which said outlets are formed. Sliding of the valve plate or slide is manually controlled by a hand wheel 34 arranged at one side of the leer. This wheel is connected to the slide valve by a short screw 35 suitably threaded in a boss 36 or enlarged portion so that with rotation of the hand wheel, the slide will move transversely of the tunnel and var the degree of opening of the outlets. eans (not shown) are provided for indicating to the operator theextent to which the outlets are opened, such means being individual to each unit. The vertical or side units 29 which depend from the transverse unit are provided near their lower ends with inwardly facing opposed outlets 37. Preferably, a set of three of these inverted U-shaped units or suction boxes B are spaced along a leer, though obviously a greater or less number may be em loyed. Pipe connections (not shown) may e provided in the suction boxes, permitting temperature determination by pyrometers.

A return passageway is arranged between the upper and lower reaches of the ware conveyor for the purpose of conducting air from the tunnel or annealing chamber through any one or more suction boxes back to a'heating unit and recuperator at the front end of the leer for recirculation through the annealing chamber. This return passageway includes a longitudinally extending pipe 40 arranged opposite the opposed outlets 37 in the vertical branches of said suction boxes. Short lengths 41 of pipe provide communication between the return pipe and the vertical branches 29 i of the suction boxes through said outlets. The rear end of the return pipe adjacent the last suction box, that is, the one most remote rom the heating unit, is closed to prevent escape of air from the tunnel to the atmosphere, and to insure return of practically all air in the tunnel to the heating unit for reheating. The front end of the return pipe extends beyond 'the suction box adacent the heating unit, and at this point is connected to a lateral branch pipe extension 42, communicating with a blower 43. This blower 43 is arranged at'one side of the leer and communicates with a transverse passageway consisting of a pipe 44 extending entirely across the leer between the upper and lower reaches of the conveyor. This last passageway is formed with a set of transversely spaced forwardly facing outlets 45 (Figs. 1 and 5) opening into a longitudinal passageway 46 leading to the recuperator.

The extreme front end portion of the annealing chamber ceiling is provided with a set of transversely spaced outlets 50 which open into a box-like unit or auxiliary suction box 51. This-suction box 51 difl'ers from the suction boxes B in that it is closed at its ends and communicates directly with the first suction box 13 beyond the heating unit by way of a longitudinal passageway 52 formed through the ceiling, so that air drawn upward from the annealing chamber A into the box 513s also circulated through the first suction box B. This as'sageway 52 is preferably provided by orming an elongated the inner end of this passageway adjacent the first main suction box and provides means whereby the auxiliar suction box at the front end of the chamber may be eliminated from the path of circulation of air. This valve 53 may be manually operated by a control handle 54 (Fig. 2) located adjacent the control wheel 34 for the valve of the first main suction box. When these valves are open and the blower 43 referred to is operating, air will be drawn from the annealing chamber A or tunnel through the outlets in the suction boxes adjacent the ends of the heating unit and recuperator, directed to the

return pipes

40 and 46 referred to, and then back to the recuperator.

The heating unit includes a transversely extending combustion chamber 60 (Figs. 3

and 4) located between the upper and lower reaches of the conveyor C and beneath the forward end of the annealing chamber. This chamber is supported in a casing 61 extending across the compartment at said front end of the leer. A fuel mixing valve 62 is arranged at one end of the combustion chamber, and may, if desirable, be so mounted that it will draw its air supply from the hot air within the lower portion of the recuperator, to be described. The opposite end of the combustion chamber is provided with an opening 63 which is normally closed but may be utilized when the type of fuel used is to be changed. The inner upper side of the combustion chamber is provided with a set of transversel spaced staggered ports 64 through w ich the products of combustion are directed to a recuperator 70.

This recuperator 70 includes upper and lower

horizontal castings

71 and 72 respectively, (Fig. 3) which extend the full width of the interior of the annealing chamber and.

are provided with vertically aligned openings 73 or ports. The lower casting 72 is in the form of an elongated chamber substantially rectangular in cross section, closed at its forward end 74 and open at the opposite or rear end 75. The rear end 75 of this chamber communicates directly with the rearwardly extendin passa eway 46 heretofore mentioned as leading to t e transverse branch pipe 44 which extends across the leer between the reaches of the conveyor.

This branch pipe, as heretofore stated, extends inwardly from a blower 43 and is provided with a set of openings through which air may be directed to the chamber at the lower side of the recuperator. A set of vertically extending tubes 77 is arranged between the upper and lower castings of the recuperator, the openings through the tubes being in register with the aligned openings 73 in the upper and lower castings. Preferably, each vertical passageway is formed by a pair of units each comprising av tubular portion having a hexagonal head7 8 integrally formed with each end. These two units are vertically aligned, bringing their passageways into register with each other and with the openings "in the upper and lower castings. In the assembly of a set of such units, the abutting heads 78 provide a central horizontal dividing wall between the upper and

lower halves

81 and 82 of the recuperator. Since the upper casting 71 of the recuperator also forms the front portion of t e annealing chamber bottom, over which the ware conveyor passes, it is evident that air directed forwardly through the

aforementioned return pipes

40 and 46 by the blower 43 will move upwardly through the recuperator and enter the forward end of the annealing chamber.

The set of ports 64 in the combustion chamber are arranged to direct the .prodnets of combustion rearwardly between the tubes in the upperv half or section of the recuperator and then forwardly through the lower half, after which they are drawn into a longitudinal flue 90 formed adjacent the bottom of the leer. The rear end of the recuperator may be sealed by one or more blocks 85 of firebrick faced with a suitable insulating material (Figure 3).

Under certain conditions and for temper ature control, elimination of one or more transversely aligned sets of tubes in the recuperator from the path of air circulation may be desired. For this purpose, the lower casting 72 is proyided with a set of transverse valve slides 86 having openings 87 which may be aligned with the vertical tube passageways, or shifted to a position in which the slides entirely or partiallyv close the tube passageways. These valve slides are of such length that portions'88extend through the sides of the leer, providing for manual adjustment. I

The longitudinal flue 90 above referred to, extends substantially the entire length of the leer and is provided with an outlet 91 (Fig. 2) at the rear end through which products of combustion are exhausted by wavof a stack 92 to the atmosphere. The top 93 (Fig. 5) of the flue is partly made up of sheet metal sections interconnected to allow for expansion. The lower casting of the recuperator and ad acent return pipe sectionsform the remainder of the ceiling. A blower 94 v is arranged .between the outlet and stack 92 for the purpose of creating a suction through said flue, insuring a proper draft through the reeuperator70 and constant exhaust of the products of combustion. Curtains (notv shownY-depend from the rear end portion of the top of said flue and contact with the forwardly moving reach of the conveyor C, preventing entry of cold air into said flue. Thus, it is seen that these curtains, together with the insulating material 22 located below the conveyor, effectively seal the end of the flue through which the conveyor enters.

The ware conveyor C may comprise the usual endless sprocket chains 96 which carry a set of transversely extending slats 97 or leer pans. At the front end, the chains 96 run over pairs of vertically spaced sprocket wheels 98 mounted upon hollow shafts 99 whose open outer ends communicate with the atmosphere at opposite sides of the leer. Preferably, these shafts 99 are formed with a series of openings 100 allowing entry of outside air into the compartment which houses the combustion chamber. Due to the suction created in the flue 90 and the direct communication between said flue and the compartment referred to as receiving the combustion chamber, there is a tendency to create a partial vacuum in this compartment. This condition and the formation of openings in the hollow shafts 99, assures such circulation of air through these shafts that they will not be affected by the intense heat present in the compartment. While the openings in the hollow shafts 99 will incidentally provide for a certain degree of cooling of the compartment containing the combustion chamber, I also provide a positive means for temperature control at this point. This means includes a valve comprising a pair of pipes 101 extending across the leer, one within the other, and having their open ends communicating with the atmosphere through opposite sides of the leer. The tubes or pipes 101 are formed with openings 102 which may be brought into register with each other, allowing entry of outside air into thecompartment under influence of suction created in the flue. Any suitable means (not shown) may be provided for causing relative rotation of the pipes to entirely or partially close the openings and thereby control the quantity of cooling air being injected into the compartment.

To prevent withdrawal of heated air from the forward end of the annealing chamberinto the compartment containing the combustion chamber, a transverse sealing plate 103 (Fig. 3) is arranged to bear lightly upon the leer pans substantially at the point of entrance into the annealing chamber. Cooperating with this sealing plate are fillers 104 rising from a plate 105 adjacent the front end of the recuperator casting and closing the spaces between the leer pans and said plate. These two elements serve to effectively prevent suction of heat from the annealing chamber at this point.

Arranged between the main suction boxes B are transversely extendin curtains 110 (Figs. 1, 5 and 6) formed of as estos or other similar fireproof material. These curtains are mounted upon transverse rollers 111 which may be manually operated by rotation of cranks 112 or handles located at one side of the leer. Suitable means (not shown) may be associated with these cranks or handles so that the operator may readily determine the extent to which the curtains are closing off a given portion of the annealing tunnel A or chamber. In the present instance, there being three main suction boxes B, there is consequent-1y a corres onding number of curtains 110 provided. 11 practice, circumstances may require application of intense heat to a zone extending only from the feeding end of the chamber to the first main suction box. Under these conditions, the curtain 110 adjacent'said suction box will be lowered so that the main portion of the heat is confined to that section of the annealing chamber in advance of this curtain. The third or last of this set of curtains is located rearwardly of the last main suction box B, permitting functioning of the curtain in connection with the suction box in the manner above outlined.

As is the usual practice, the delivery end D (Fig. 2) of the leer isopen on both sides and the top for a considerable distance to expose the annealed ware to the atmosphere and allow cooling to a degree permitting removal from the conveyor by hand. From the front end of this exposed area to a point spaced a short distance from the last named curtain, the walls of the leer are only lightly insulated to permit cooling of ware. The ceiling of the tunnel is of considerable thickness at the forward end, particularly directly over the recuperator 7 0 to prevent undue dissipation of heat. The ceiling decreases in thickness to a pointspaced a short distance rearwardly from the last named curtain and at this point terminates, leaving the upper side of the chamber to be closed by other means. This other means includes sets of upwardly opening shutters 115 (Figs. 1 and 8) which may be adjusted allowing escape to the atmosphere of heat rising from the ware. Preferably, I employ the two adjacent sets of longitudinal shutters 0r wings 115 adjacent the delivery end of the tunnel, each set including a pair of opposed wings or vanes which are hinged to brackets 116 arranged at the upper longitudinal edges of the lower side Walls. The inner adjacent longitudinal edge ortions of the wings 115 may be supported by an inverted T-iron section 117 which extends centrally and longitudinally of the leer tunnel as in Figs. 1 and 8. At correspond ing ends of each pair of opposed shutters or vanes, transversely aligned pulleys 118 are fixed at the hinge point and interconnected by means of a cable 119. This cable 119 has one deliver-y end of the tunnel.

end and an intermediate portion attached to these pulleys, the other end being fixed to a threaded rod 120 which extends through the side wall of the tunnel, and a bracket 121 arranged upon the outer face of the wall. A hand wheel 122 formed with an extended hub portion 123 is threaded upon said rod 120 so that with rotation of the wheel in one direction, the cable 119 will be moved to rotate the pulleys and elevate the opposed shutters 115 simultaneously and to corresponding degrees and form a central passageway through theupper side of the tunnel. This construction allows opening of the sets of shutters to different degrees, and conse: quently permits variance of the rate of cooling of the ware, as will be pointed out.

At times, there is a tendency for cold drafts of air to be blown into the tunnel from the delivery end fD. Such drafts would result in a portionof the heat in the leer being blown outwardly through the feeding end of the tunnel, thereby necessitating an increase in the quantity of heat supplied to the leer and incidentally causing added expense for fuel. Naturally, such cold drafts would set up undesired strains in the ware passing through the leer. To avoid this objection, I

have provided adjacent the first pair of shutters 115 and entirely within the tunnel, a pair of longitudinally spaced transversely extending roller curtains 125 (Figs. 1 and 7) which may be constructed of asbestos or the like material. By adjustment of control handles 126 at one side of the leer, the curtains 125 may be lowered to any necessary degree and thereby create a separate chamber which, in a sense, is a vacuum compartment. Arranged between-these curtains, is a transverse suction box 127 extending across the ceiling of the tunnel and connected at one end to a vertical pipe 128 (Figs. 1 and 7) forming communication between this box and the flue 90 through which products of combustion are directed to the atmosphere from the heating unit. This suction box is provided with a set of transversely spaced outlets communicating with the interior of the tunnel and adapted to be opened partially or entirely by means of, a slide valve 129. This slide valve is controlled by a hand wheel 130 at one side'of the leer in the same manner that the valves of the main suction boxes B are regulated. Thus, it is seen that due to suetion in the flue 90 through which products of combustion are exhausted, suflicient suction will be created in the suction box 127 between said curtains 125 to exhaust any cold drafts entering the compartment from the The suction created in this chamber may be readily. controlled by adjustment of the valve 129 in the suction box so that all of the cold drafts entering the chamber will be removed and prevented from entering the main tunnel, yet

ciable quantity of warm air out of the tunnel proper. In the initial operation of the leer, it is desirable and necessary to close the tunnel at its forward end to walls and interior, by reason of which a vertical sliding insulated gate 131 is arranged at this end (Figure 3). The opposite ends of this gate move in vertical guides 132 whose upper ends are connected by a cross bar 133.. A pair of vertical threaded rods 134 have their lower ends connected to the gate and extend upwardly through said cross bar 133. The upper portions of these rods are threaded through bevel gears 135 which run in mesh with other bevel gears 136 on ashaft 137, to one end of which shaft an operating handle 138 is fixed. This gate may be adjusted to difi'erent elevations as required for feeding of any particular type of ware being annealed, thereby eliminatin the necessity of having a relatively large fee opening Where small ware is being annealed. This adjustment quite obviously minimizes the quantity of cold air entering the feeding end of the leer. I As is theusual practice, the ware conveyor C is driven by a power plant or unit located at the delivery end of the leer and including a motor 139 and drive connection 140 to a transverse shaft mounting sprocket wheels over which the ware conveyor runs. The operation of the leer may be stated as follows: i i

In describing the operation, reference to atmospheric air is intended to distinguish between fresh air and the products of combustion used in indirectly heating the air, and does not necessarily mean air at atmospheric pressure.

Assume that the heating unit is functioning, directing products of combustion through the recuperator around the vertical tubes and into the forward end of the flue in the bottom of the leer,- and that the conveyor is being moved by its driving unit. In the event heavy ware is bein annealed and a high initial application of heat to the ware entering the leer is desired, the first main suction box B adjacent the recuperator and the auxiliary box 51 at the feeding end of the annealing chamber will be opened permitting Withdrawal of air from the chamber at these two points. The curtain 110 rearwardly of this main suction box is lowered to prevent movement of the intense heat rearwardly of this curtain, thereby confining the ware heating zone to that area forwardly of the curtain. Operation of the blower 4-3 forces circulation of atmospheric air forwardly through the return pipe 46 and upwardly through the recuperator tubes 73 into the heating zone of the annealing chamber and then to both ends of the selected zone for permit heating up the withdrawal through the suction boxes. All of thisexhausted air is then drawn downwardly through the vertical branches of the main suction box and thence to the blower and caused to recirculate through the recuperator and heating zone. The air entering the heating zone absorbs the heat which rises from the ware being introduced into the chamber, thereby utilizing an element which has heretofore been a liabllity difficult, if not impossible, to eliminate.

Due to the passage of the returning reach of the ware conveyor through the flue along the floor of the leer, the conveyor is heated to such a degreeby the products of combustion that prior to entering the annealing chamber, the conveyor pans have reached a temperature substantially the same as that of the ware being fed into the leer. This condition eliminates drawing of heat by the conveyor pans from the ware and prevents setting up of strains in portions of the ware, which strains result from uneven temperature in the glass structure and if not eliminated prevent formation of the best quality Ware.

Control of temperature in a predetermined heating zone may be attained in several different ways. Closing of certain of the slide valves at the lower ends of the recuperator tubes reduces the effective heating capacity of the recuperator, which, together with the fact that the volume of air in circulation has not been changed, results in such rapid circulation of atmospheric air through the tubes remaining open that this air is not heated to a degree which was attained when the entire set of tubes was being utilized. In other words, closing of certain of these tubes without reduction of the blower effectiveness in the return passageway, causes an increased speed in the circulation of air through the recuperator so that it does not absorb heat units to the extent permitted by opening of the tubes. Thus the temperature of the annealing heat is decreased.

Further, control of the temperature ob viously may be effected by cutting down the fuel supply as is practiced in the operation of many leers.

The temperature may also be varied by lengthening the heating zone without changing the adjustment of the heating unit, and thereby distribute a given quantity of atmospheric air throughout a greater area of the tunnel, increasing its path of circulation and consequently cause reducing of temperature of the air to a lower degree before reaching the recuperator, than where the heating zone is relatively short. This manner of controlling the temperature of the heated air and the distance through which the air is carried, permits making the annealing curve high or low in temperature and of any desired length- After the ware passes from the heating zone, it enters what may be termed a dead air space, in which space the ware temperature is reduced uniformly and gradually. From this zone, the ware entersthat section of the tunnel whose upper side is provided with the adjustable shutters. The first pair of shutters may be opened providing a relatively narrow longitudinal passageway along the center, allowing escape of heat rising fromthe ware, while the next adjacent pair of shutters are opened to a degree providing a relatively wide opening through which heat may escape from the ware to the atmosphere. Obviously, adjustment of these shutters will vary according to the type of ware being annealed.

From the rear end of the last pair of shutters, the ware is carried by the conveyor to the delivery point and is exposed on all the sides and the top to the atmosphere so that it may be sufliciently cooled to permit removal by hand. The auxiliary suction box 51 at the feeding end of the leer serves a secondary, yet important function, in that it exhausts cold drafts of air which enter the feeding end of the annealing chamber. Ordinarily, these cold drafts would come into contact with certain portions of the ware in the heating zone and set up strains, the elimination of which is the primary function of this heating zone.

As heretofore stated, contact with the ware, of cold drafts entering the delivery end of the tunnel, is prevented by the presence and operation of suction in the box 127 arranged in the vacuum chamber forwardly of and adjacent the ceiling shutters 115.

The application of the products of combustion directly to the-Ware conveyor prior to entry of the latter into the annealing chamber, effectively and sufliciently heats the conveyor pans so that additional or special pan heating means is unnecessary. Heretofore, approximately fifty percent of the heat has been utilized in maintaining a proper temperature in the conveyor pans. The compartment in which the combustion chamber is arranged and through which the ware conveyor runs, may at times be too hot and consequently heat the conveyor pans to a higher degree than is desired. To overcome this, the inlet valve 101 below the combustion chamber is opened allowing drawing in of outside air and consequent reduction of the temperature of air in the compartment. This injection of air, together with that natur rally drawn in through the openings in the tubular shaft 99 which carries the front set of conveyor sprockets, allows accurate temperature control in the compartment located in advance of the recuperator.

Heating of ware in the annealing chamber by means of atmospheric air entirely free of foreign material, instead of by the prodofand highly efiicient operation.

Manifestly, certain changes may be resorted to within the spirit and scope of my invention.

What I claim is:

1. A leer for annealing glassware comprising an annealing chamber, a flue extending longitudinally of and below said chamber, a ware conveyor running through said chamber and flue, a single heating unit, means for introducing products of combustion into said .unit, means for transferring heat free or products of combustion to the annealing chamber from said unit, and means directlyapplying products of veyor in said flue.

2. A leer for annealing glassware comprising an annealing chamber having longitudinally spaced sets of outlets in its ceiling, a recuperator below the forward end of said chamber and communicating therewith, re-

combustion to the conturn pipe connections between the ceiling outlets and the recuperator, means for continuously recirculating air through the annealing chamber, return pipe and recuperator,

and means for introducing products of combustion into the recuperator for heating the latter, said recuperator formed to prevent co-mingling of the products of combustion and air being heated. V

3. A leer for annealing glassware comprising an annealing chamber, a heating unit below the forward end of said chamber, means for dividing the chamber into heating zones of varying lengths, means for exhausting air from either end of a heating zone, and'means for recirculating theexhaustcd airthrough the heating unit.

4:. A leer comprising an annealing chamber having longitudinally spaced sets of outlets in its ceiling, adjustable curtains arranged between certain of said sets of outlets to divide said chamber into heating zones, a

heating unit below the forward end of said chamber, individual pipe connections between said outlets and the heating unit, means for circulating air thru said pipe connections and heating unit and rearwardly thru said annealing chamber, and valves for the outlets whereby to control the exhaust of air from the heating zones. 7 v

5. A leer comprising an annealing chamber having longitudinally spaced sets of valved outlets in its ceiling, adjustable curtains arranged between certain of said sets of outlets to divide said chamber into heating Zones, a heating unit below the forward end of said chamber, means for circulating air through heating unit below the said heating unit and rearwardly through said annealing chamber, pipes connecting the several heating zones and said unit, for coning'unit and heating it by means of said prod-- nets of combustion but without contact with the latter, and means for drawing said air through a' selected heating zone and recirculating it through the heating unit.

7. A leer for annealing glassware comprising an annealing chamber, a heating unit at the forward end, means'for supplying heated air through the heating unit to the annealing chamber, means for exhausting portions of the air through the'ceiling of the annealing chamber at a point in advance of the heating unit, means for exhausting the remaining portion at a point rearwardly of the unit, and means for continuously circulating the exhausted air through the heating unit and annealing chamber.

8. A leer comprising an annealing chamber, a closed flue spaced below and extending longitudinally of the annealing chamber, a heating unit arranged between the forward ends of the chamber and fine, an endless'ware conveyor running through the annealing chamber and sa-idflue, means for directing the products of combustion to said flue and into direct contact with the lower reach of the conveyor, means causing indirect heating of air by said unit, and means for injecting the heated air into the annealing chamber and then causing recirculation of the air through said unit. 4

9. A leer comprising an annealing chamber, a flue spaced below and extending longitudinally of the annealing chamber, a heating unit arranged between the forward ends of the chamber and flue, an endless ware conveyor running through the annealing chamber and said. flue, means for directing the products of combustion to said flue and into direct contact with the lower reach of the conveyor, means causing indirect heat ing of air by said unit, means for injecting the heatd air into the annealing chamber and then causing recirculation of the air through said unit, and means for varying the temperature in said flue. I

10. A leer comprising an annealing chamber, a flue spaced below and extending longitudinally of the annealing chamber, a heating unit arranged between the forward ends of the chamber and flue, a ware conveyor running through the annealing chamber and said flue, means for directing the products of combustion to said flue and into direct contact with the lower reach of the conveyor, means causing indirect heating of atmospheric air by said unit', means for injecting the heated air into the annealing chamber and then causing recirculation of the air through said unit, means for varying the length of a heating zone in the chamber. and means for exhausting air from both ends of a heating zone.

11. A leer comprising an annealing chamber, means dividing the chamber into heating zones, a flue spaced below and extending longitudinally of the annealing chamber, a heating unit arranged between the forward ends of the chamber and flue, a ware conveyor running through the annealing chamber and said flue, means for directing the products of combustion to said flue and into direct contact with the lower reach of the conveyor, means causing indirect heating of atmospheric air by said unit, means for injecting the heated air into the annealing chamber and then causing recirculation of the air through said unit, means for varying the length of a heating zone in the chamber, and means for exhausting air from either end of a heating zone.

12. A leer for annealing glassware comprising an annealing chamber, an air heating unit beneath the forward end of the chamber, and means for forcing circulation of the heated atmospheric air rearwardly through a' portion of the chamber and then back through the heating unit for reheating and return to the chamber.

13; A leer including an annealing chamber, a recuperator having a set of vertical tubes open at both ends and communicating with forward end of said chamber at their upper ends, said chamber having outlets spaced along its ceiling, means providing communication between said outlets and the lower ends of the recuperator tubes, means forcing airthru the tubes into said chamber and thence thru the outlets to the lower ends of the tubes, and means outside the tubes for heating the latter and by radiation heating the air passing thru said tubes.

14. A leer including an annealing chamher, a recuperator having a set of vertical tubes open at both ends and communicating at their upper ends with the forward portion of said chamber, said chamber having outlets spaced along its ceiling, means for forcing air thru the tubes into said chamber and exhausting it thru said outlets, means to conduct the exhausted air to the lower ends of the recuperator tubes, and a combustion chamber extending transversely of the front end of the recuperator, said combustion chamber arranged to direct products of combustion over the exterior of the tubes and indirectly heat air passing therethru.

15. A leer including an annealing chamber, a recuperator having a set of vertical tubes open at both ends and-communicating at their upper ends with said chamber, said chamber having outlets spaced along its ceiling, means for forcing air thru said tubes into the annealing chamber and exhausting the air thru said outlets, means to conduct the exhausted air to the lower ends of the recuperator tubes, means separating the recuperator into upper and lower sections, means for directing products of combustion rearwardly thru the upper section and forwardly thru the lower section of the recu ierator over the exterior surfaces of the tu es, a longitudinal flue arranged below the recuperator to receive products of combustion from the lower section of the recuperator, and means for exhausting products of coinbustion from the opposite end of said flue to the atmosphere.

16. A leer including an annealing chamber, a recuperator having a set of vertical tubes open at both ends and communicating at their upper ends With said chamber, said chamber having outlets spaced along its ceiling, means for forcing air thru said tubes into the annealing chamber and exhausting the air thru said outlets, means to conduct the exhausted air to the lower ends of the recuperator tubes, means separating the recu erator into upper and lower sections, means or directing products of combustion rearwardly thru the upper section and forwardly thru the lower section of the recuperator over the exterior surfaces of the tubes, a longitudinal flue arranged below the recuperator to receive products of combustion from the lower section of the recuperator, means for exhausting products of combustion from the opposite end of said flue to the atmosphere, and an endless ware conveyor running thru the annealing chamber and said flue, said conveyor being heated by the products of combustion prior to entering the annealing chamber.

17. A glassware annealing leer comprising a ware receiving tunnel, an endless conveyor having a ware carrying reach running thru said tunnel, and a single means to heat at least a portion of the ware receiving tunnel by radiation and heat theconveyor by direct contact of products of combustion with the conveyor just prior to entry of the latter into said tunnel.

18. The method of annealing glassware which comprises passing a series of glass articles through a tunnel, introducing a heating medium into the tunnel, causing the medium to move lengthwise of the tunnel, ex-

hausting the heating medium with heated air and gases rising from the glass articles, re-

heating the exhausted air, and returning the air into the tunnel at a point forwardly of the exhausting station.

19. A glass annealing leer comprising an annealing chamber including bottom, top and side walls, a substantially inverted U-shaped passageway in the top and side walls, means providing communication between said chamber and the horizontal portion of the passageway, a heating unit below the forward end of said chamber, means for directing air through the heating unit into the annealing chamber, and means for exhausting air from the chamber through said passageways and recirculating it through the heating unit.

20. A glass annealing leer comprising an annealing chamber including bottom, top and side walls, a substantiallyinverted U-shaped passageway in the top and side walls, means providing communication between said chamber and the horizontal portion of the passageway, a heating unit below the forward end of said chamber, means for directing air through the heating unit into the annealing chamber, means for exhausting air from the chamber through said passageways and recirculating it through the heating unit, and means for controlling exhaust of air into said passageway.

21. A glassware annealing leer comprising an annealing chamber, an air heating unit below the forward end of the chamber, means for directing air through the heating unit into the chamber adjacent the feeding end,

longitudinally spaced outlets communicating with the chamber through the ceiling, a re-' turn passageway providing communication between all of said outlets and the heating unit, and means for conducting heated air from the said outlets to the heating unit and chamber.

22. A glassware annealing leer comprising an annealing chamber, an air heating unit below the forward end of the chamber, means for directing air through the heating unitinto the chamber adjacent the feeding end, longitudinally spaced outlets communicating with the chamber through the ceiling, a return passageway providing communication between all of said outlets and the heating unit, means for exhausting heated air from the annealing chamber through said outlets and recirculating the air through the heating unitand chamber, and means for closing certain of the ceiling outlets to'vary the length of a heating zone.

23. A glass annealing leer comprising a tunnel, a heating unit below the forward end of the tunnel, a longitudinal flue beneath the heating unit and tunnel, means for exhausting products of combustion from the heat ng unit through said flue, means for supplying air to the tunnel through said heating unit, and means adjacent the delivery end of the tunnel to exhaust back drafts of air into 24. A leer comprising an annealing chamber,'a unit including a recuperator and heater arranged below the forward end of the chamber, means spaced from and enclosing the combustion chamber and forming a compartment in advance of and below said combustion chamber, a flue extending rearwardly beneath the annealing chamber and communicating at its front end with said compartment, a ware conveyor moving through said flue and compartment and into the annealing chamber, and means for drawing products of combustion through said flue to heat the conveyor prior to entry of the latter into the annealing chamber.

25. A leer comprising an annealing chain-- her, a unit including a recuperator and heater arranged below the forward end of the cham ber, means spaced from and enclosing the combustion chamber and forming a compartment in advance of and below said combustion chamber, a flue extending rearwardly beneath the annealing chamber and communicating atits front end with said compartment, a ware conveyor moving through said flue and compartment and into the annealing chamber, means for drawing products of combustion through said flue to heat the conveyor prior to entry of the latter into the annealing chamber, and means permitting injection of cooling air into said compartment.

26. The method which consists in passing articles on a conveyor through an annealing chamber containing an annealing medium free of products of combustion, and using products of combustion to preheat the conveyor.

27. The method which consists in passing articles on a conveyor through an annealing chamber containing an annealing medium free of products of combustion, recirculating the medium to anneal subsequent articles passing through the annealing chamber, and using products of combustion to preheat the conveyor.

28. A leer for annealing glass articles comprising an annealing chamber extending lengthwise of the leer, a conveyor extending through said chamber lengthwise thereof, a heating device adjacent one end of said chamber, and means for causing a continuous circulation of air through said heating device for heating the air and thence through the annealing chamber in the direction of its length and back to the heating device, said circulating means including a suction box having openings into the annealing chamber at points intermediate its ends whereby a portion of the air is drawn from the annealing chamber at a point intermediate its length lengthwiseof the leer, a conveyor extending through said chamber lengthwise thereof, a heating device adjacent one end of said chamber, means for causing a continuous circulation of air through said heating device for heating the air and thence through the annealing chamber in the direction of its length and back to the heating device, said circulating means including a suction box having openings into the anealing chamber at points intermediate its ends whereby a portion of the air is drawn from the annealing chamber at a point intermediate its length and another portion of the air is conducted through the chamber beyond said openings, and valve mechanism for adj ustably varying the amount of air drawn through said suction box.

30. A leer for annealing glass articles comprising an annealing chamber extending lengthwise of the leer, a conveyor extending through said chamber lengthwise thereof, a heating device adjacent one end of said chamber, and means for causing a continuous circulation of air through said heating device for heating the air and thence through the annealing chamber in the direction of its length and back to the heating device, said circulating'means including a plurality of suction boxes at different positions lengthwise of the annealing chamber.

Signed at Toledo, in the county of Lucas and State of Ohio, this 11th day of August,

PERCY Q. WILLIAMS.