US2497621A - Lehr for glassware - Google Patents

Description

Feb. 14, 1950 u as. MERRILL LEHR FQR GLASSWARE Filed Nov. 23, 1945 g In van for:

mm w mw mv mw V (2H7 HM, m h r a m N aw a: k v w WV m 1 0|. N E Q wm S S g Q m f Q m 2 Dg'zald/GMerrill Attornqy Patented Feb. 14, 1950 LEHR FOR GLASSWARE Donald G. Merrill, West Hartford, Conn, assignor to Hartford-Empire Company, Hartford, Conn., a corporation of Delaware Application November 23, 1945, Serial No. 630,332

13 Claims.

This invention relates to the art of annealing glassware and more particularly to improvements in lehrs of the type having an elongate tunnel through which the ware is moved and in which a heating passage is provided at the bottom of the annealing portion of the tunnel and is supplied with hot products of combustion, as from a burner. An air conducting pipe is provided in this portion of the tunnel adjacent to the heating means and has discharge orifices from which jets of air are discharged directly into the tunnel. The heating means serves to radiate heat directly to the ware thereabove and also to preheat the air supplied by the air pipe in the tunnel. The jets of preheated air are discharged from such pipe at such places and in such directions as to set up desirable circulatory currents in the tunnel atmosphere surrounding the ware. The temperature gradient of the ware during its passage through the annealing portion of the tunnel of the lehr will thus be controlled in part by the heat radiated thereto from the underneath heating means and in part by the circulatory currents in the tunnel. Since the products of combustion do not contact the ware in this type of lehr, any desired fuel, including oil, may be used.

A lehr f the character above described is disclosed in my Patent No. 2,133,784, of October 18, 1938, for Method of and apparatus for annealing glassware. The present invention provides an improvement over that lehr.

According to the present invention, the heating apparatus and the air conducting and discharging apparatus in the lehr tunnel have novel features of construction and arrangement which enable them to perform their several and cooperative or combined functions in a highly efficient manner. These apparatuses may be installed in a lehr which previously had been openfired and therefore had required the use of a gaseous fuel and a plurality of burners so as to convert such an open-fired lehr into a muffled heating-air circulating lehr of the type above described. In the latter, a liquid fuel and the products of combustion produced by a single liquid fuel burner may be utilized to supply all the additional heat required to set up and maintain the desired temperature gradient in the ware during its passage through the annealing portion of the lehr tunnel. The walls of the parts of conducting apparatus are caused to pass directly beneath and up the far sides of some of these heat radiating parts so as to pick up additional heat before they join the circulatory currents in the tunnel.

The arrangement of cooperative jets of preheated air and heat-radiating combustion products-conducting parts is novel and advantageous in that it serves to effect adequate further heating of the jets of preheated air in an improved manner and also controls the temperature gradient of the ware in the overhead portion of the tunnel and the heat-radiating action of the longitudinally extending heat-radiating surfaces of the heating apparatus. Preheating of the air in an improved way is aided by arranging heat conductive portions of the air conducting structure so that they are in effect coils. These coils are located in heat exchanger chambers at the bottom and sides of the tunnel at a substantial distance from the ware-entering end of the latter. The products of combustion, which by this time have lost considerable heat, are brought to these chambers and caused to travel back and forth therein in heating relation to the coils to heat the air in the latter before the spent products of combustion are permitted to pass out of the heat exchanger chambers to a suitably located exhaust passage. The arrangement just described has a high efficiency in the use of the heat produced by the operation of the single burner.

Other novel features and advantages of the invention hereinafter will be pointed out or will become apparent from the following description of a practical embodiment of the invention, as illustrated in the accompanying drawings, in which:

Figure 1 is a horizontal section of the annealing portion and a fragmentary portion of the subsequent, cooling portion of a lehr equipped with structure of the present invention, the vie-w being approximately along the line ll of Fig. 2;

Fig. 2 is a generally longitudinal vertical section approximately along the line '22 of Fig. 1; and

Fig. 3 is "a transverse vertical section approximately along the line 3--3 of Fig. 1, the parts on top of the lehr tunnel being omitted.

Figs. 1 and 2 show, in a somewhat diagrammatic manner, what may be termed the annealing section, designated 1, of an elongate, substantially horizontal lehr tunnel, generally indicated at 2 in all the views. The annealing section I of the lehr tunnel extends from its front or ware-entry end, indicated at 3 in Fig. 2, to approximately the place along the tunnel at which there is an upward jog 4 in the tunnel bottom. The annealing section l of the lehr tunnel is so termed because the ware undergoing treatment in the lehr may have its temperature controlled and regulated during passage through this portion of the tunnel so as to be lowered from an upper annealing temperature-at which strains in the glass of the Ware will be relieved to a lower annealing limitat which the glass of the ware has become sufficiently rigid to preclude further molecular rearrangement therein. Below the lower annealing limit, permanent strains cannot be introduced into the ware which, however, may still require controlled further cooling for the removal of temporary strains and so that the ware may be cooled to a temperature suitably low to permit handling of the ware soon after it leaves the lehr tunnel. The lehr tunnel that is partially shown in Figs. 1 and 2 will, of course, have a cooling section, which -may=belike that disclosed in my aforesaid Patent No. 2,133,784, through which the ware will be transported and subjected to further cooling after leaving the annealing section I. This cooling section-is represented in the drawings (Figs. 1 and 2) by the fragmentary portion thereof indicated at 5. Further illustration and description thereof are not required since a lehr tunnel havingan annealing section equipped with the improvement features of the present invention may also include any suitable known cooling section, equipped with any suitable known ware cooling provisions.

The ware to be annealed will be carried through the lehr tunnel on the upper stretch B of an endless, woven-wire belt 7, only a portion of which is shown since both it and the means for operatively supporting, guiding and driving itare in well-known and wide-spread use in tunnel lehrs'. Itis sufficient herein to state that the. upper stretch 6 of the ware conveyor 7 slides on a horizontal supporting and guiding metallic framework 8, Figs.- 2 and 3, which may rest at spaced points onsuitable refractory supports,

including the upstanding pillars 9 on the tunnel bottom, Figs. 1, 2 and 3, and blocks II] on the refractory top H, Fig. 2, of a heating chamber, hereinafter described, that is located in the lower part of the forward portion of the lehr tunnel.

The tunnel walls may be constructed of any suitable, known materials, arranged and supported in any suitable known manner, all as well known in the art. The tunnel has a through passage comprising a portion I2 extending through the annealing section I of the tunnel and a further section 1 3 in the succeeding section of such tunnel. The passage 12 is open at the front of the lehr tunnel, at 3, Fig. 2, to afford clearance for theware (not shown) on the lehr conveyor, which of course will travel in the direction tocarry the ware into the front end of and through the tunnel passage.

The heating apparatus provided by the present invention is located in the annealing section of thelehr tunnel, mainly below the lehr conveyor supporting and guiding framework 8. Such heating apparatus comprises a heating chamber comprising a combustion compartment or space I 4, Figs. 1 and 2, which, as shown in Fig. 1, extends the full width of the front end portion of the tunnel passage l2 at the bottom thereof and is provided at one end with a burner port I15, formed in one of the side walls of the tunnel, with which a burner I6 is operatively associated.

The combustion space I4 has a rear wall I! which extends transversely of the tunnel from the side wall of the tunnel that is provided with said burner port toward but not to the opposite side wall of the tunnel, whereby a restricted opening or passage [8 is provided at the rear of the end portion of the combustion space 14 opposite the burner between such combustion space and a more rearwardly located space or compartment 19 in the aforesaid heating chamber. The space or compartment [9 also may occupy the full width of the lower portion of the tunnel passage. Its continuity is interrupted at intervals by refractory pillars arranged in transverse rows, one comprising right and left hand pillars 20, another right and left hand pillars 2| and an intermediate pillar 22, and a third comprising the transversely spaced pillars 23. These pillars not only serve as supports for the refractory top H of the heating chamber but as bailles by which the heated products of combustion which pass from the combustion compartment is through the opening I8 into the space l9 are dispersed or distributed throughout the latter space and are retarded more or less in their flow to right andleft hand rearwardly directed ports or passages 24 in the rear Wall 25, Fig. 1, of such space. The space l9 of the heating chamber therefore may be termed a heated productsdistributing space or compartment. The arrows in the heating chamber, as shown in Fig. l, indicate in part the flow of the heated, products and the distribution thereof in such chamber as. they pass to the ports or passages 24.

From the space [9, the heated products; of combustion pass through the rear ports or passages 24 directly into theforward ends of longitudinally extending rig-ht and left hand similar heating ducts 26. These may have light gauge walls of a refractory material having good heat conducting properties or they may be made of any other suitable known material that is sufficiently heat resistant and conductive. The ducts 26 have a partially flattened or oblong shape in cross-section. See Fig. 3. They may extend for the greater part of the length of the annealing section of the lehr tunnel. They are supported at intervals so as. to be. close to' the side walls of the; tunnel but spaced therefrom as well as from the tunnel bottom. The major transverse axes of these ductsextend transversely of the tunnel. In the example shown,v the ductsextend through suitable, closely fitting openings 2'! in thepillars 9', by which the ducts are supported as above described. The. cross-sectional configuration ofthe ducts and the manner of their support provide substantial advantages in the assembly of elements provided by the invention, as hereinafter will become clear.

The ducts 26 discharge their gaseous contents at their rearward ends into inlet ports 28 in the front walls of a pair of right and left hand bottom heat exchanger chambers 29. These are located in the bottom part of the rearward portion of the tunnel passage I 2 and togetherext'end the full width of that passage, having a common inner side wall 30, Fig. 1, at approximately the longitudinal median line of the lehr tunnel. The chambers 29- have spaced, overlapping or staggered transverse partial partitions or baffles which extend from-the outer side walls of the chamber, as indicated at 3| and 32, respectively, and from the inner sidewall ofsuch chamber, as

indicated at 33. In consequence of these baffles,

the products of combustion passing through the inlet ports 29 into the chambers 29 travel back and forth in such chambers along horizontal zig-zag or sinuous paths, as indicated by the arrows in such chambers, until they arrive at the rearward portions of the chambers. The products of combustion then may leave the chambers through outlet ports, one of which is shown at 34 in Fig. 1, so as to enter vertical heat exchanger chambers 35 in the side walls of the tunnel. Each of these side heat exchanger chambers 35 is provided with spaced, overlapping or staggered vertical partial partitions or baffles, as shown at 36 and 31, respectively, for one of such chambers in Fig. 2, whereby the products of combustion entering each such side chamber will travel vertically upward in the rear portion thereof to the upper part of such chamber, thence downwardly between the bafiles 36 and 31 to the lower portion of the chamber and then upward again in the forward portion .of such chamber to a final discharge space 38 at the top of the chamber, as shown in Fig. 2. From the final discharge space 38, the products of combustion will enter a branch exhaust pipe 39, there being two of these pipes 39, one for each of the two discharge spaces 38. Such branch exhaust pipe has a portion 49 which is in effect a Venturi tube. An eduction air pipe 4| discharges into the branch exhaust pipe below the Venturi portion so that an effective draft will be set up in the branch exhaust pipe. There are, of course, two of the eduction air pipes, one for each branch pipe 39. The branch exhaust pipes 39 may converge together to form a single final exhaust pipe 42.

The air preheating and circulating apparatus may comprise a blower 43, located at the top of the tunnel structure. A rearward air discharge pipe 44 of the blower may be divided at 45 to provide a pair of right and left hand branch air pipes 46. Each pipe 46 may supply air under pressure to the eduction air pipe 4| hereinbefore mentioned. In addition, each branch pipe 46 leads to a header within the upper part of the corresponding side heat exchanger chamber 35 adjacent to the forward wall of the latter. One of these headers is indicated at 41 in Fig. 2. A set of vertical air pipes 48, four in the example shown, conduct air from the header 4! downwardly in the front part of a side heat exchanger chamber 35 to a header 49 in the bottom part of such chamber. The header 49 is connected at 50 to a second bottom header 5|. From the latter, another set of air pipes 52 extend vertically between the bafiies 36 and 31 to a second top header 53 in the chamber 35. From the top header 53, another set of air pipes 54 extends downwardly to a third bottom header 55. The latter is connected at 56 to a fourth bottom header 5! which is operatively connected to a set of four horizontal air pipes 58 in the rear part of the adjacent bottom heat exchanger chamber 29. The pipes 58 connect to a rear inner header 59 in the chamber 29. The header 59 also is operatively connected by a second set of four horizontally extending air pipes 60 to a header 60a in the outer side portion of such chamber, see Fig. 1. The header 60a. is also operatively connected by a second set of horizontally extending pipes 6! with an intermediate header 62 at the inner side of the chamber 29. The header 62 is connected by a second set of horizontal pipes 63 to a front header 64 in the outer side of the chamber. From the header 64, another set of pipes 65 leadsto a front inner side header 66.

The arrangement of headers and connecting pipes constitute connected air conducting coils in the communicating bottom and side heat exchanger chambers.

From the headers 66, longitudinal air pipes 61 extend through the front walls of the bottom heat exchanger chambers 29 forwardly in the lower part of the tunnel passage 12 between the heating ducts 26, as best seen in Fig. 1. At intervals along their lengths, the pipes 6'! discharge jets of air, as indicated at 68, laterally toward the heating ducts 26. In the example shown, the jets 68 are directed in a slightly downwardly inclined direction laterally toward one or the other of the longitudinally extending heating ducts at places intermediate adjacent supporting pillars 9. The preheated air supplied by these jets will pass laterally directly across the lower surfaces of the supported portions of the ducts between adjacent pillars and thence upwardly between the sides of these portions of the ducts remote from the air pipes and the side walls of the tunnel, as indicated by arrows in Fig. 3, meanwhile extracting heat from such ducts. At their forward ends, the pipes 61 are provided with upwardly stepped or offset laterally turned discharge pipes 69 which may be integral portions of the pipes 61 or, if formed separately, may be operatively joined thereto in any suitable known manner. The discharge pipes 69 are closed at their extremities, as indicated at 19, and discharge generally forwardly directed jets of air H over the heat-radiating top i I of the main heating chamber, as shown in Fig. 1.

The blower 43 may have a forwardly directed air discharge pipe 12 which is provided at its extremity with an air nozzle 13, Fig. l, suitably associated with the burner 16 and the port l5 to support combustion of the fuel discharging from the burner and within the combustion space [4.

The operation and some of the advantages of the illustrative embodiment of the invention just described will be readily understood. Since the products of combustion produced by the operation of the burner cannot reach the ware, a liquid fuel, such as a suitable fuel oil, may be used. Only a single burner may be required. The operation of this burner may provide the requisite heat in an efficient and economical manner when the burner is used in conjunction with heating and air circulating provisions, such as hereinbefore pointed out. The heating chamber may radiate heat to the ware in the front portion of the passage I2 to bring such ware quickly to the relatively high temperature required for relief of strains in the glass thereof. The heating ducts 26 also radiate heat to the ware and lose heat to the circulating air. The gases passing through the ducts 26 will be highly heated on entering such ducts and will lose heat gradually and uniformly en route to the bottom heat exchanger chambers. In the latter, full advantage is taken of the heat remaining in such gases to preheat the air in the air conducting coils within such chambers. The air-preheating structure requires but a relatively small part of the length of the lehr tunnel, this because of the compact arrangement of air conducting coils and associate heating provisions.

The air discharging from the sides of the longitudinally extending air pipes 61 will pass laterally outward beneath and then upwardly at the outer sides of the relatively flattened or oblong heating ducts26and thus will scrub over the lower and outer side surfaces of these ducts before being directed upwardly by the side walls of the-tunnel passage past the sides of the conveyorsupporting and guiding framework. The preheated air sup plied by the jets 58, which, on discharge'from the air pipes 6'1, may be too cool to be suitable for introduction into the ware-containing portion of the tunnel, will be supplied with sufiicient additional heat by the ducts 26 to be sufliciently heated for such introduction as such air passes'laterally outward beneath and upwardly at theouter. sides of the heating ducts 2%. In the ware transporting part of the tunnel passage, the air currents will be directed inwardly to approximately the vertical median line of such passage and then downwardly around and against the ware, through the open-work ware conveyor and its open-work supporting structure, and back to the air jets discharging from the pipes 67. The circulation is approximately as shown by the arrows in Fig. 3 and will be repeated so as to recirculate at least part of the air. Thus, the tunnel atmosphere will be circulated and recirculated about and past the ware on the moving conveyor in the annealing section of the lehr tunnel. Desirable control and regulation of the temperature gradient of the ware passing through this section of the tunnel may thus be obtained.

The front jets H of preheated air are further heated by the top wall of the heating chamber. They then pass upwardly into the front part of the tunnel passage so as to oppose ingress of cold air at the front of such passage. Some of these jets H, as the end jets of the series, may be turned slightly toward the side walls of the tunnel, as shown. Some of the air from these jets may pass out of the tunnel through the open front end of the tunnel passage. The remainder of such air may move rearwardly until it comes under the influence of a transverse circulation, with which it will then combine.

The invention is not limited to the details of the illustrative embodiment of the invention herein particularly described as many changes therein and modifications thereof will readily occur to those skilled in the art.

I claim:

1. Apparatus for annealing glassware, comprising an elongate tunnel, means for conveying glass? ware therethrough, mufile means located wholly beneath the path of the ware in the tunnel for, passing relatively highly heated gases longitudinally of the tunnel beneath and in heat-transfer ring relation with the ware passing therethrough, said mufile means having a delivery end located a substantial distance along the tunnel from the front end thereof, heat-exchanging means operatively connected to the delivery end of said mufiie means and located in said tunnel in part below and in part at a side of the path of the ware, an air blower operatively connected to said heat exchanging means to supply thereto air to be preheated, and air conducting and discharge means operatively connected to said heat exchanging means to receive preheated air therefrom and to direct such air into the tunnel.

2. Apparatus as specified in claim 1 wherein the heat-exchanging means extends across the bottom of the tunnel and up the sides thereof.

3. In apparatus for annealing glassware, an elongate tunnel comprising an annealing section extending from the front end of the tunnel for a substantial part of its length, an open-work conveyor for conveying glassware through the tunnel along a path spaced above. the bottom of said annealing section, heat exchanging means in saidannealing section of the tunnel, said heat exchanging means comprising a series of connected air conducting coils located in part beneath and in part at'a side of the path of the ware and heated media conducting means constructedand arranged to cause heated media passing therethrough to envelop said coils, muflle heating means Within said annealing section extending from nearthe front end of the tunnel longitudinally thereof fora substantial part of thelength thereof and having a delivery end operatively connected with said heated media conducting meansiof the heat exchanging means to supply heated media to the latter, and means operatively connected withsaid series of coils and extending in said annealing section below said pathof the ware to receive preheatedair from said seriesof coils and to dischargejets of such air. into saidtunnel.

4. In. apparatus. for annealing glassware, an elongate tunnel, means for conveying glassware through the tunnel, a muffle heating chamber-in the tunnel beneath the path of the ware, a heated media conducting duct operatively connected with said muffie heating chamber and extending a substantial distance in said tunnel below the pathof the Ware and in heat transferring relation therewith, heat exchanging. means in said tunnel into which said duct dischargesheated media, said heat exchanging means including air conducting coils in position therein to receive heat from the heated media therein, and an air conductingpipe to receive preheated air from said coils and to discharge-jets of the preheated air laterally therefrom in the lower part of the tunnel across the bottom surface of said mufiie heating duct.

5. Apparatus as specified in claim 4 wherein said duct-is substantially oblong in cross-sectional configuration and has its major transverse axis approximately horizontal.

6. In apparatus for annealing glassware, an elongate tunnel, means for conveying glassware through the tunnel, communicating side and bottom heat exchanger chambers in. said tunnel, the former extending at a side of the path of the ware and the latter being located below said path, a seriesof connected air conducting coils in said heat exchanger chambers, means operativelyconnected to one end of said series of coils to supply airunder pressure thereto, mufile heating means-extending in said tunnel below the path of the ware to supply heated media to said bottom heat exchanger chamber, and means operatively connected to the other end'of said series of coils to conductpreheated air longitudinally ofsaid' tunnel below the path of the ware and todischarge jets of the preheated air into said tunnel.

'7: Apparatus as specified in claim 6 wherein said mufiie heating means comprises a duct having heat-radiating walls and of substantially oblong configuration in cross-section, said duct being located in said tunnel in positionto be scrubbed across its" bottom surface by jets of the preheated air discharged in said tunnel, the major axis of said duct being approximately horizontal.

8. In apparatus for annealing glassware, an elongate tunnel comprising an annealing section extending from the front end of the tunnel for a-substantial part of its length, means for conveying glassware through said tunnel, a heating chamber in the lower part of said annealing section .below-the'epath of the ware and adjacent'to the frontend' of i the tunnel, heat exchanging means in the annealing section at a substantial distance from said heating chamber, said heat exchanging means comprising a pair of relatively right and left bottom chambers in the tunnel below the path of the ware and relatively right and left side chambers in the side walls of the tunnel and respectively communicating with the right and left bottom chambers, a series of connected air conducting coils in each set of communicating side and bottom chambers, relatively right and left heating ducts extending in the lower part of said tunnel below the path of said ware and respectively connecting the heating chamber with the right and left bottom chambers so as to deliver heated media to the latter, means connected to the ends of said coils in the side chambers to supply air under pressure to said coils, and air conducting pipes operatively connected to the other ends of said coils and extending longitudinally of the lower part of the tunnel forwardly thereof between said heating ducts, said air conducting pipes being constructed and arranged to discharge spaced jets of preheated air laterally from their outer sides directly beneath and upward at the far sides of said heating ducts.

9. Apparatus as specified in claim 8 wherein said heating ducts are approximately oblong in cross-sectional configuration, have their major transverse axes substantially horizontal, and are spaced above the bottom and inwardly from the side walls of the tunnel at the places toward which said jets of preheated air are directed.

10. Apparatus as specified in claim 8 wherein said heating chamber has a burner port and a liquid fuel discharging burner operatively associated therewith, and in combination therewith, a branch air supply pipe operatively connected with the means for supplying air to said coils to 10 supply air adjacent to said burner to support combustion of fuel supplied by the burner.

11. Apparatus as specified in claim 8 and, in addition, exhaust means operatively connected with said side chambers, and means operatively connected with the means to supply air to said coils to also supply air to said exhaust means to aid a draft therein.

12. Apparatus as specified in claim 8 and, in addition, a pair of oppositely extending, upwardly offset, lateral air discharge pipes operatively connected at their adjacent ends to the forward ends of said longitudinally extending air conducting pipes, and closed at their remote ends, said lateral air discharge pipes being constructed and arranged to direct jets of preheated air generally forward over the top of said heating chamber.

13. Apparatus as specified in claim 8 and, in addition, a pair of oppositely extending, upwardly offset, lateral air discharge pipes opel'atively connected at their adjacent ends to the forward ends of said longitudinally extending air conducting pipes, and closed at their remote ends, said lateral air discharge pipes being constructed and arranged to direct jets of preheated air generally forward over the top of said heating chamber, the generally forwardly directed jets nearest to the side walls of the tunnel being turned slightly toward such walls.

DONALD G. MERRILL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,486,265 Pike Mar. 11, 1924 2,133,784 Merrill Oct. 18, 1938 2,335,128 Merrill Nov. 23, 1943

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