US2300426A - Glass melting furnace - Google Patents

Description

Nov. 3, 1942. 1 s; LoNGENl-:CKER 2,300,425

Guss MELTING FURNACE 'File-d .Jima 29, 1940 2 sheets-sheet 1 lNvEN TQR Nov. 3, 1942. L s. LONGENECKER 2,300,426

' GLASS MELHNG FURNACE l .Fileduuneza 1940 '2v sheets-snee; 2'

Patented Nev. 3, 1942,

UNITED STATES PATENTv OFFICE GLASS MELTING FUaNAcE Levi S. Longer-lecker, Mount Lebanon, Pa. y Application June 29, 1940, Serial No. 343,186

z3 claims. (ci. 49-54) This invention relates to continuous tank type glass melting furnaces, to ports vand roofs for such furnaces, and to the roofs of the regenerators forming part of such furnaces.

While the prior patent art discloses furnaces of this type which are provided with what may be termed long continuous ports, none of these structures, so far as I am aware, are used in commercially successful furnaces.

Among the patents referred to` are such as Crowley Patent 1,828,830 and Drake Patent 1,828,833, of October 27, 1931; Mambourg Patent 1,860,045, of May 24, 1932, and Showers et al. Patent 2,010,419, of August 6, 1935.

The Crowley, Drake and Mambourg patentsdisclose roofs ofthe sprung arch type for both the furnace and regenerators, while theShowers et al. patent discloses suspended roof structures both for the furnace chamber and the regenerators. 4

While the advantages of so-called long continuous ports have been recognized, and designs for the same have been known for' some years, as witnessed by the above patents, no furnaces utilizing any such ports are, so far. as I am aware, in actual use today. The furnaces in use today employ individual relatively short ports, and While suspended roofs for the furnace and regenerative chambers are disclosed in at leastone of said patents, no commercial furnace employing roofs of this type and long continuous ports, so far as I am aware is now in operation. e

Since furnaces of the type here contemplated are reversed during operation, the ports not only serve to deliver the combustible mixture-made up of fuel and preheated air--to the furnace chamber, but serve as outlet ports for the hot products of combustion as theyleave the furnace chamber on their way to the regenerative chambers adjacent thereto.

If not in all, at least in a large majority of thecommercially successful furnacesof the type here contemplated using natural gas or oil as fuel the fuel is introduced through burner blocks placed in the side walls of the ports in such a way as to `direct the fuel jets or streams into the preheated stream of air passing through the port. It has been found by\experience that the burner blocks when placed'in the sides of the ports have a much longer effective life than when placed where they are directly in the path ofthe outgoing hot products of combustion.

In commercial practice, the individual ports some have now reached a length of about seven` feet, but these are 'still using burner blocks which are located in the sides, or what may be more properly termed the ends thereof. This, however, has necessitated a much increased velocity in the fuel passhig through the burner blocks,

and, as a result, has quite materially shortened distinct name streams, one located adjacent each port end, with an air stream located between An object of this invention is to produce a practical longl substantially continuous port structure for furnaces of this type, by means of which it is possible to obtain a ribbon of flame extending throughout the length of the l port and which will cover the Whole surface of the glass bath,'thereby eliminating shadows or idle glass surfaces found. between individual ports in present day commercial furnaces.

Another object is to produce a port and roof for glassv melting furnaces which` will not only have been lengthened from time to time" until simplify the construction of-suchfumaces, but which will establish a. stream linefiiow of air and gas and thuspermit greatlyincreased operating` efciency.

A still further Objectis to produce improved suspended roof structures, notonly for the heating chamber, but for the regenerative-chambers as well. y

A stillfurther object is to produce a suspended roof structure for glass meltingl furnaces of the type under consideration which will cause a turbulence in the heating flames adjacent the longitudinal center line of the furnace for the purpose of insuringcomplete combustion of the unl burned fuel passing the longitudinal center line of the furnace so that the temperature will be uniform across the heating chamber from port to port. e

A still further object is to produce a suspended' port roof andknuckle by means of which the flame can be so anchored as to eliminate any cold spots in front of the port.

A still further'object -is to produce a. port construction such that the distance between the 'port floor and roof can be accurately based on the desired port velocity.

Another object is to produce a heating furnaceichamber roof structure by means of which it is possible to place the roof at the proper height above the glass level to obtain the `maximum permissible B. t. u. release per cubic foot of furnace volume.

Another object is to produce a suspended roof and port knuckle structure for glass melting furnaces by means of which maximum B. t. u. release may be uniformly obtained throughout the furnace heating chamber above the glass bath.

In the present day commercial glass melting furnaces because ofthe type of ports and the type of furnace roof used, the heating chamber from incoming to outgoing ports is not of uniform temperature. The temperature in the heating chamberl above the bath adjacent the outgoing ports may vary from that adjacent the incoming ports as much as from 400 to 500 and due to the spotty method of firing utilized in commercial furnaces, certain local spots obtain the maximum B. t. u. release while other spots obtain no appreciable B. t.- u. release. This makes a spotty and ineiiicientv operation, and a further object of this invention is to produce a glass melting furnace in which a uniform and high B. t. u. release may be obtained throughout the entire width of the combustion space between ports.

These and other objects, which will be apparent to those skilled in this particular art, I attain by means of the structures described in the specification and illustrated in the drawings accompanying and forming part of this specication.

Inthe drawings:

Figure 1 is a fragmentary transverse vertical section of a continuous tank type glass melting furnace embodying this invention. This view 'illustrates about one half of the furnace above the regenerator checkers.

Fig. 2 is a transverse vertical section similar to Fig. 1 but illustrates the full width of the furnace above the regenerator checkers and embodies a modification in the roof structure adjacent the longitudinal center line .of the furnace, whereby the turbulence above referred to is obtained.

Fig. 3 is a composite view in vertical section with the left-hand half taken on the lie III-III of Figs. l and 2 and the right-hand half taken on line IIIa-IIIa of Figs. 1 and 2 with portions `of the support structures omitted. i

Fig. 4 is a perspective view illustrating the port iioor and roof structure as viewed from the left side of Figs. 1 and 2.

Fig. 5 is a view partially in section and partially in elevation and is taken4 on line V-V of Fig. 2 looking toward the outlet side of the port on the right-hand sideof Fig. 2; and

Fig..6 is a fragmentary sectional view of still another modified form of roof structure for producing turbulence adjacent the longitudinal center line of the furnace and is taken on line VI-VI of Fig. 2.

In the furnace chosen as an embodiment of this invention, I0 represents the refractory door or bottom of a furnace tank of usual construction. II- II represent the refractory side walls of the tank. I2 represents my fiat suspended roofmade up of interlocking refractory tile or blocks such as broadly disclosed in Patent 1,590,303 issued to meon June 29, 1926. The tile or'roof blocks are preferably supported from top` of the checker bricks and which divides the A vertically extending refractory wall I8` spacedfromfeach tank side wall II forms one vertical wall of one of the regenerative chambers, which are shown as of the horizontal type and which have an outer'wall I1, checker bricks I8 and a horizontal floor I9 extending over the regenerative chambers into checkerwork chambers and upper longitudinally extending chamtransverse and longitudinal beams I8 and I il, by 75 bers 20 thereabove and which serve as the mani- 'fold for feeding the regenerator uptakes.

The regenerator uptakes are provided with vertically extending partition walls 2| which enter the chamber 20 and have the effect of vanes for causing an even upward flow of the air which is preheated in the checker chambers. The roof 22 of each regenerative chamber is preferably formed by refractory tile or blocks such as broadly disclosed in my Patent 1,590,303 and these are preferably suspended from longitudinal beams 23 in the manner disclosed in Patent 2,126,901 issued to me on August 16, 1938.

The vertical wall 24 of each regenerator uptake portion is formed of interlocking refractory blocks such as above referred to and these are preferably supported in the manner dsclosedin Patent 1,977,799 issued to me on October 23, 1934. A row or course of nose blocks 25 joins roof 22 and vertical wall 24 and is preferably constructed and supported in the manner disclosed in said last patent.

Adjustable sliding dampers or gates 26positioned between vertical partitions 2l of each regenerator uptake portion and between the end partitions 2| and the end walls 27 of the regenerative chamber, are slidably supported on 'ledges formed for that purpose in said partitions and end walls.

Port 29 which embodies this invention, is preferably of a length equalling the length of the boiling zone of the furnace or the degassing zone thereof as the case may be; there preferably7 being separate ports for each of these zones, but if desired my continuous port may embrace both such zones. Of course, each such zone has ports on opposite sides thereof which alternately serve as inlet ports and outlet ports as is usual.

The floor of each port 29 is formed of alternately arranged high and low portions as shown in Fig. 4 whichbridge the gap between vertically extending walls II and I6 .of the tank and regenerators respectively.

The low portions are formed by refractory slabs 39 which in the main are horizontal, but which incline. somewhat from wall II to wall I6 as shown in the drawings, in order to provide suitable drainage for refuse deposited thereon during the time the ports serve as outlet ports.

Each high portion of the floor is formed of two triangularly shaped blocks 3I-3I which are spaced apart and which are supported by vertical walls Il and I6 and bridge the gap therebetween. These tile are provided with shoulders 32 which parallel their'top edges and which form supports for tile or blocks 33 which close space therebetween and formcovers or roofs for the high portions of the floor. Tile or blocks 3I y are in effect burner blocks, since each is provided f with an outwardly tapering fuel orifice 34 into the narrow endof which a fuel pipe 35 dis-4 charges a spray of fuel such as oil or ay stream of natural gas. .These sprays or streams can be regulated by means of valve 3,6. A fuel supply line 3l which extends through the space between walls I I and I6 beneath the port fioor connects with fuel pipe 35.

Walls I I and I6 of the tank and checker chambers respectively are supported and braced in the usual manner as diagrammatically illustrated in Fig. 1. The space between said walls, which is provided as usual with a cat walk 38, gives access to the burner pipes and valves as well as to the furnace blocks and the support means for walls II and I6.

From the above, it will be seen that my port oor is crenelated and that the crenelles and merlones or cops extend through the port from the inletA to the outlet side thereof. It will also be apparent that the fuel sprays orstreams are fed into those portions of the air stream which traverse the crenelles and that the burner orifices being located'as they are in the side walls of the merlones or cops are as favorably positioned as are the fuel orifices in the present day commercial furnaces of the type here contemplated. In other words, the burner blocks do not form target walls for the hot products of combustion while ports 29 are being used as outlet ports.

The roof of my port 29 is formed by a depending knuckle 39 which extends the full length of the port and is made up of rows or courses of refractory tile or blocks such as broadlyydisclosed in my Patent 1,590,303 and which are preferably suspended as disclosed in my Patent 1,913,168. This knuckle in conjunction withthe port floor acts as a venturi and increases the air velocity to a point'where it is, greater than the velocity of flame propagation and thus anchors the flame within or adjacent the'throat ofthe venturi.

Th furnace roof or rather that part of the furnace roof located between one of the knuckles 39 and the adjacent vertical or apron wall 24 of the uptake portion Aof the adjacent regenerator chamber, is made up of alternately arranged courses of long tile' or blocks 40 and short tileor blocks 4I. These courses of llong blocks in effect provide guiding vanes which extend from knuckle 39 to vertical wall 24 and prevent side slipping of the pre-heated air stream as it flows from the regenerator uptaketo port 29.

The arrangement of the long and short blocks or tile 4D and 4I with relation to the crenelles and 3 and 4 of the drawings. i

It will be noted that the suspended roof 22 of the regenerators is located a considerable distance below the port floor and that the regenerator uptakes which are divided into ues by partitions 2| are of materially less cross sectional area than the cross sectional area of chamber 20 which serves as a manifold for the same. From this it will be understood that the `velocity of the preheated air flowing upwardly through the uptake merlones of the port floor is clearly shown in Figs.

is sumciently increased to make the port and roof guiding vanes most effective in combing the top and bottom surfaces thereof into parallel lines of flow. Thefuel streams, which are also parallel; contact the underside of the air stream with a minimum amount of interference. This improves in thev the luminosity of the name and also localized hot spots.

The air stream preheated in the regenerator not only contacts with, and blankets the furnace roof and the knuckle 39, .but portions of such stream. fiow through the crenelles and it is into these portions that the fuel isdrected through the burner orifices.

The oppositely directed fuel streams'entering each crenelle meet, and, defiecting one another, are directed toward the port outlet. The air stream portions traversing the crenelles in which combustion is initiated, and the deflection of the fuelstreams, combined with the expansion due to this initial combustion, causes the fuel and air streams traversing the crenelles to fan out laterally so as to overlap the merlones or cops at the tank or outlet end of port 29, thus producing a continuous ribbon of the combustible mixture of air and fuel. 1

As the upper or main portion of the` air stream flowing in contact with the roof of the port formed by knuckle 39 is deflected downwardly by the knuckle so that its lower portion comes in contact with the ribbon of fuel and thus aids combustion, it produces a ribbon of ame which com-V pletely covers the surface of the bath in front of the port. 4

The upper section of this air blanket protects the knuckle as well as the heating chamber roof This not onlyv prevents carbon deposits vbut excessive wear and from direct name impingement.

tear on the refractories forming the knuckle and the furnace roof or crown.

Dampers or gates 26 for the regfnerator uptakes are utilized for varying the amount of air supplied to different sections of port 29: it being readily understood that it will generally be neces; sary to provide heavier firing for certain sections of the port than for others. especially where the .mrt is utilized in the boiling zone of the furnace. By using these dampers for controlling the air, and valves 36 for controlling the fuel. I in effect establishzones within each port. which zones receive different volumes of combustible mixture. These zones extend Vacross the furnacefrom port to nort` and the combustible mixture supplied to each zone is-so directed by my port floor and knuckle that a uniform mixture of fuel andair is supplied throughout thefull width of eac-h zone. whereby I secure -the maximum permissible B. t. u. release above every square foot of glass or batch located therein. 1

The fiuted structure of the port floor which in effect divides the lower portion of the air stream into parallel branches. prevents side slipping of the stream toward either end of my continuousv The guiding means formed by long' roof blocksl 40 also aids in preventing side slipping of the combined streamvof air and fuel traversing the port. i

-By introducing the fuel into the crenelles of my continuous port, I am able to operate with a prevents any much lower fuel pressure than used in the present day lcommercial glass melting furnaces.

It will be apparent thatl knuckle 89 can be placed at just the proper position to locate the shadow or cold spot so that it falls on the port iioor instead of the surface of the glass directly in front of the port, as it does in the present'day commercial type of furnace. These cold spots are not only idle surfaces, but are especially harmful in the boiling zone.

With the continuous ports of this invention, it is possible to locate the point of heaviest firing 'so that it will at all times completely blanket the boiling zone and particularly the foam line. 'Ihese continuous ports also eliminate the cold spots on the glass bath which occur between the ports of the present day commercial furnaces of this type.

vBy utilizing knuckle l5 which extends along or adjacent the longitudinal center line of the zone in which my ports are used, that is, along the center hne of the boiling zone or the center line of the degassing zone, as the case may be, or

` along the center line of both of these zones, I

definitely establish a point of turbulency. which completes the mixture of any unburned fuel and air. This final rapid mixing insures complete combustion of all of the fuel before it enters the port which at the time is serving as the outlet port and provides a uniform temperature across the furnace chamber from port to port. This is important because combustion which is completed in the outlet ports is not only wasteful of fuel and loss of temperature ahead of the port, but adds to the wear and tear on the refractories.

This turbulency-producing knuckle, instead of being continuous as in Fig. 2, may be formed, if desired, as disclosed in Fig. 6, that is, with alternating at and knuckle sections. Such a construction will not only produce turbulency, but the knuckle sections will serve as guiding vanes to keep the name from side slipping.

Having thus .described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A glass melting furnace including a furnace chamber and a tank for molten glass located below said chamber, a suspended roof for said chamber which while flat in the main is provided adjacent its longitudinal center line with a suspended crenelated knuckle which serves not only to create turbulency but to prevent side slipping of the fuel traversing the heating chamber.

2. In a glass melting furnace including a furnace chamber and a tank for a molten glass bath located below said chamber, a suspended roof for said chamber, which while flat in the main is provided adjacent its longitudinal center line with a downwardly extending knuckle.

3. In a glass melting furnace including a furnace chamber and a tank for a molten glass bath located below said chamber, a suspended roof for said chamber, which while flat in the main is provided adjacent its longitudinal center line with a portion which is located closer to the glass bath than the at portion thereof.

4. In a glass melting furnace including a'furnace chamber and a tank for a molten glass bath located below said chamber, a suspended roof for said chamber, which while at in the main, .is

provided adjacent its longitudinal center line with a suspended turbulency-creating knuckle.

5. In a glass melting furnace of the type having a heating chamber, a tank below said chamber for containing a bath of molten glass, an air preheating regenerator on each side'of said tank,

and ports for alternately discharging into opposite sides of said chamber and above the molten bath level in said tank, a combustible mixture of fuel and preheated air, a structure for each such port comprising a floor extending from the uptake'of the adjacent regenerator to the adjacent tank side and having cop-like high portions alternating with crenelle-like low portions throughout the length of the port, and a sus pended knuckle-like roof section above said oor,

in combination with means for discharging fuel into those portions of the preheated air stream traversing the crenelle-like low portions of the oor.`

6l In a glass melting furnace of the type having a heatingchamber, a tank below said chamber for containing a bath of molten glass, an air preheating regenerator on each side of said tank, and ports for alternately discharging into opposite sides of said chamber and above the molten bath level in said tank a combustible mixture of fuel and preheated air, a. structure for each such port having a oor extending from the uptake of the adjacent regenerator to the adjacent tank side and comprising cop-like high portions and crenelle-like low portions alternating therewith throughout the length of the port, and a suspended knuckle-like roof section above said oor, in combination with means for discharging fuel through the sides of the cop-like high portions and into those portions of the preheated air stream traversing the crenelle-like low portions.

7. In a glass melting furnace of the type having a heating chamber, a tank below said chamber for containing a bath of molten glass, an air preheating regenerator on each side of said tank, and ports for alternately discharging into opposite sides of said chamber and above the molten bath level in said tank, a combustible tions of the preheated air stream traversing said low portions.

8. In a glass melting furnace of the type havingga heating chamber, a tank for molten glass beneath said chamber, air regenerators on opposite=sides of said tank and relatively long port's on opposite sides of said chamber for discharging into said chamber air preheated in said regenerators. each such port having its upper wall formed as a suspended knuckle-like roof section and its'lower wall or oor made up of low portions alternating with hollow high portions each having more or less triangularly shaped and spaced ported side walls and a top which slopes downwardly in oppositedirections from its approximate center line, and means for discharging fuel through said side wall ports and into the preheated air traversing said low portions.

9. In a glass melting furnace of the type having a heating chamber, a tank beneath said chamber for molten glass, air regenerators on opposite sides of said tank having vertically extending uptakes, and relatively long side ports for discharging into said chamber air preheated in said regenerators, a suspended roof for said heating chamber and" which includes knucklelike portions which form the roofs or tops of said ports, and a section which extendsoutwardly from each knuckle over the adjacent regenerator uptake and is provided with vanes for preventing side-slipping of the preheated air passing from said uptakes to saidv por-ts.

10. A relatively long port structure for discharging preheated air into the heating chamtively deep portions of the air stream.

. 11. A relatively long port structure for discharging preheated air into the heating chamber off a glass melting furnace, comprising a knuckle-like roof or upper wall and a crenellated floor in which the cops and crenelles alternate throughout the length of the port; the construction and arrangement being such that an air stream traversing said port is formed as a continuous air blanket extending from end to end of the port with depending deep portions joined to and depending from said blanket; said" '-with means for discharging fuel into the relathe horizontal area of said chamber and is adapt-v ed to supply preheated air to` said port,` a suspended low level roof section above the regenerator chamber, a suspended roof section above said oiftake, and a sectionally supported vertical wall connecting the roof sections above said rey generator chamber and said oiftake.

16. In a glass melting furnace,a suspended roof provided at opposite sides thereof, with knuckles,

which, co-operating with port floors therebe-` neath form ports for discharging preheated air into the furnace, regenerator chambers on oppostesides of the furnace, and each having an otake which, extending vertically above the same, is of materially less horizontal area `than that of its regenerator chamber, for supplying preheated air to the vport on its side of the furnace, a suspended low level roof section 'above each regenerator chamber, a suspended roof section aboveveach oiftake and having guide vanes for preventing side slipping of the preheated air,

ber, a suspended roof which, while fiat in the 'main is provided adjacent opposite sides and adjacent its longitudinal center line with suspended knuckles, and port floors below the side knuckles and which with said knuckles form.

ports fondischarging fuel and air into the furnace chamber.

13. In a glass melting furnace of the type having a heating chamber, a tank for molten glass below said chamber, air preheating regenerators on opposite sides of said tank and relatively long ports onopposite sides of said chamber for discharging into said chamber air preheated in said regenerators; each of said ports having a floor made up of low and hollow high portions alter- `nately arranged throughout its length and a knuckle above said fioor forming the top of said port, which is substantially straightv from end to end of the port andis spaced a distance above the tops of said high portions, in combination with means for discharging fuel through the side walls of said hollow high portions and into-the spaces above said low portions.

14. The combination of a regenerator chamber having an oitake extending vertically above the same and of materially less horizontal area than that ofthe regenerator chamber, a suspended roof section over the regenerator chamber,'a suspended roof section over the offtake and a sectionally supported vertical wall connecting said roof section: K y i 15. In a glass melting furnace, a suspended roof provided at one side thereof with a knuckle, which, cooperating with a portiioor therebeneath forms a port for discharging preheated air into the furnace, a regenerator chamber having an offtake which, extending verticallyabove the same, is of materially less horizontal area than 7.5

and sectionally supported vertical walls connectlng the roof sections above the regenerator chambers and said oitakes. i

17. In a glass melting furnace having 'a furnace chamber, a suspended roof for said chamber, and which on one side thereof has a knuckle, which, co-operating with a port iioor therebeneath, forms a port for discharging preheated air into the furnace chamber, a regenerator chamber on one side of the furnace, and having an offtake, which extending vertically above said regenerator chamber', is divided into separate flues by vertically extending partitions, a suspended roof section above the regenerator chamber, a suspended roof section above said oitake and which has guiding vanes extending from said oftake to said port to prevent sideslipping of the air into the furnace chamber, a regenerator chamber on one side of the furnace, and having an offtake which extending vertically above the same, is divided into separate iiues, a suspended roof section above the regenerator chamber, a suspended roofsection above said offtake and which has guidingvanes extending from said oiftake to said port to prevent sideslipping of the preheated air, a sectionally supported vertical wall connecting the roof sections above said offtake and said regeneratorchamber,` and means extending through'said vertical wall for independently controlling the effective area of said ues and therefore the delivery of preheated air to said port.

19. In a furnace of the type having a heating 'chamber with side ports, air-regenerators on opposite sides of said chamber and each having a vertically extending uptake for discharging through said ports airpreheated in said regenerators, a suspended roof for said heating chamber having a section which extends outwardly over each regenerator uptake and is provided with vanes for preventing sideslipping of the preheated air passing from said uptakes to one of said ports.

20. In afurnace of the type having a heating chamber, an air regenerator-having a vertically extending uptake, a port for discharging into said chamber air preheated in said regenerator, a suspended roof for said heating chamber and which includes a knuckle-like portion which forms the roof of said port, and a roof section which extends outwardly from said knuckle over the regenerator uptake and is provided with vanes for preventing sideslipping of the preheated air passing from said uptake to said port.

21. A glass melting furnace including a furnace heating chamber and a tank for molten glass 1ocated below said chamber, a roof for said chamber which, While at in the main, is provided -adjacent its longitudinal center line with a depending crenellated knuckle which serves not only to create turbulency, but prevents sideslipping of the fuel traversing the heating chamber,

22. A glass melting furnace including a 'furnace chamber and tank for molten glass located below said chamber, a roof for said chamber which, vWhile at in the main, is provided adjacent its longitudinal center line with a downwardly extending knuckle.

23. A glass melting furnace including a furnace heating chamber, a tank for molten glass located below said chamber, a roof for said cham- -ber which, while ilat in the main, is provided adjacent its longitudinal center line with a turbulency-creating knuckle.

LEVI S. LONGENECKER.

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