US1941807A

US1941807A - Gas-bulb heating apparatus

Info

Publication number: US1941807A
Application number: US414009D
Authority: US
Inventors: Adolph W Machlet
Original assignee: Individual
Current assignee: Individual
Priority date: 1920-12-14
Filing date: 1920-12-14
Publication date: 1934-01-02
Anticipated expiration: 1951-01-02

Description

Jan. 2, 1934. I w ET 1,941,807

GAS BULB HEATING APPARATUS Filed Dec. 14. 1929 2 Sheets-Sheet l MW W%M Jan. 2, 1934. A. w. MACHLET 1,941,307

GAS BULB HEATING APPARATUS Filed Dec. 14, 1929 2 Sheets-Sheet 2 Hfmme Patented Jan. 2, 1934 GAS-BULB HEATING, mana'rns Adolph. w. Machlet, Elizabeth, s. J.

Application December 14,- 1920 Serial No. 414,009!

19 Claims.

This invention relates to apparatus for the manufacture of electric light bulbs and other devices, in which glasshas to'be heat-treated, by means of Bunsen burners, to soften the delicate glass parts and weld one to another.

It is a desideratum to produce electric light bulbs and other glass articles cheaply and great quantities by machinery, but, in the process of their manufacture, it is found necessary to apply to the glass articles exact specific heats, and these heats must continue for exact specific times. The glass article is first heated by one gas-burner, to a certain exact degree andfor a certain exact number of minutes; and later on, while the glass article still remains in'the operating machine, it is exposed successively to the heat of other sets of burners, for different but exactly measured lengths of time, and to a different but exactly measured degree of heat from the first burners; each heating varying in-intensity'and duration from all the others.

It is found in these accurately-timed glassmaking machines that great difficulty develops because of unforeseeable fluctuations in the heat which occur in the same burner. Owing to these variations, the glass article will be 'exposed'to too low a heat in some cases, but the duration of exposure cannot be prolonged, so that the article fails to receive the proper heat treatment, and must be thrown away. Even though the heat may be known to be too low at the moment, s'till the duration of the heating is fixed,,since in these machines it is not practical for an-attimdant to watch the work and prolong the heating where the intensity is insufficient. The loss from defective bulbs or other articles is verygreat.

One of the main objects of this invention is to overcome this practical difiiculty. It'has been proposed to provide means for regulating the heat at each burner, and attempting to control "re fluctuations of the burners individually, but,

for a true solution, the problem is approached from a different direction, according to the pres ent invention.

While the faults of the burners are usually attributed to deficiency in the quality of thejfuel gas, I have conceived-that the fault is mainly in the air'that is used. Atmospheric airis subjected to varying conditions, and I have .found that air in the burners varies largely in humidity, from day to day, and even' from hour to hour.

If the day is cold, the burnersxact better than crease of humidity on a warm day. These great- 1y varying degrees of humidity I conceive produce faults in the effect of the gas-burners.

Theburners in the furnace must fire exactly I and uniformly right for radio tube machines. I

maintain that if the moisture content of the air should'fluctuate, orif, at any time, it should be excessive, there is a consequent fluctuation in the heating of the article which is exposed to the burners, which originally must be accurately set or focused on the work. This fluctuation is a great drawback in this and other classes of work. Such fluctuationshave proven a source of great expense and loss in manufacturing radio tubes. The trouble, however, I have contrived to overcome by controlling the air humidity, as setfforth herein. The air forms such a large proportion of the burning mixture that the control of the humidity of the air reduces the fluctuation of heat at the burners to a pointthat largely overcomes existing troubles.

The burners used in the glass machine are of the :kind in which compressed air is mixed with fuel gas and supplied to the burners under pressure, and the trouble has been commonly attributed to variations'in the .quality of the fuel gas, but'I-have contrived in studying this problem to avoid variations in the degree of heat emitted at the burners by contriving to secure a uniformity in the hun'iidityv of the compressed air which mixeswith the gas and forces it through the burners. "The volume of air in the mixture is about five times the volume of gas, and uniformity of heat at the burners is secured, ac-

cording to this-"invention, by passing atmospheric air through a cold coil, the temperature of which maybe, say, 34 degrees. The air passes through this cold coil on its Way from or to the ,airblower or pump. By this means the air is deprived of much orall of its humidity. The moisture collects in water traps provided at the delivery endof the cold coil. Between said delivery end and the burners, there is no opportunity for the air to reabsorb moisture, and the degree of moisture present in the air going through the burners may "be uniform and unvarying.

This is of use {in reducing .or avoiding fluctuations ;in the heat of the burners, and avoids great "loss in manufacturing glass bulbs, and effects saving in cost of operation and increase in the and gefliciency of the bulb-making machine, and improvement in the oua'lity'of the manufactured articles.

If it is desired to regulate the degree of moisture present in the air'tha't is used in the mixend 12 of a coil having a header 13.

ture for the burners, this can be done by increasing or decreasing the coldness of the drying coil. If the burner mixture contains too much humidity, whereby the flame is rendered too weak, the temperature of said coil may be reduced, to eliminate more of the humidity; and vice versa. Preferably the temperature of the cooling coil is regulated automatically, so that the air in the burner mixture is uniform so long as the bulb-making machine is in operation.

The air delivered by the cooling coil is of uniform dryness, notwithstanding fluctuations in the humidity of the atmosphere as it is received by the coil. One of the advantages gained is the avoidance of fluctuations in humidity of air used in the burners. Another advantage is that a substantially higher degree of heat than heretofore may be obtained by the burners, the dried air engendering hotter flame.

It will be understood that if the cold dry air were delivered directly from the regulatable cooling coil to the furnace-burners, under pressure from the pump, the consumption of air at the burners would vary with the degree of cold. According to the present invention, the temperature of the dried air is brought to a higher point, which is uniformly maintained, so that consumption remains uniform at the burners, which is a desideratum in many classes of work. The matter of mixing the cold air with gas also demands attention; and these problems are best solved by first bringing the dried air to a roomtemperature, which remains substantially uniform while the furnace is running.

It is important to have an even voliune of gas delivered to the burners, which is the reason for bringing it to room-temperature. The pressure remains constant, and the room-temperature constant, so that the flow of air to the burner will be maintained constant.

After the required moisture is taken out from the air, preparatory to burning, the heating of the cold dry air to room-temperature does not vary the moisture content or the dryness of the air which is delivered to the burners.

The room-temperature may be say 60 degrees, and the operation of the burner may thus be kept at maximum efficiency because of the uniform dryness and uniform temperature of the compressed air.

It will be understood that while the apparatus so far explained will remove the dampness from the air preparatory to sending the same through the burners, still the apparatus does not need to be regarded merely as a dampness remover, for it is broadly capable of controlling the degree of humidity of the air that is delivered therefrom.

Other features and advantages will hereinafter appear.

In the accompanying drawings,

Figure 1 is a sectional elevation of one form of organization for producing high heat with uniformity.

Figure 2 is a sectional front elevation of the main portion of the apparatus seen at Figure 1.

Atmospheric air for use in the burners of the glass-bulb heating furnace is taken through an inlet pipe 10, which is attached at 11 to intake The entering air is divided up into numerous streams in the coil, by means of a row of sub-coils in the form of return pipes 20, 20 19, said sub-coils extending horizontally at 20 from the baseheader 13, and rising at 20 and returning at 19,

where they are connected to delivery header 14 arranged at suitable distances above the header 13. The headers and the described connecting pipes form a principal coil.

This coil is submerged in a tank 15, which is filled with brine or other refrigerating liquid 16. The air in passing through the submerged coil on its way to the furnace becomes chilled. Its contained moisture, whose proportions are fluctuating, is cooled, and becomes dissociated from the air and condenses, and drops of the condensed humidity collect in the pipes 20 and 20 and flow to the bottom of the header 13, which is provided with an outlet 1'7 to any suitable water trap 18, in which the condensations accumulate and from which they are discharged from time to time.

Each connection between the

headers

13, 14 may include pipes 19, 20 of great length, so as to secure ample circulation of the more or less 95, humid air through the sub-coils. The moisture that collects in the upper reaches 19 drops through vertical pipes 20 and runs along return pipes 20 into the header 13 and escapes into the trap. 10L

By this means the air is deprived of all of its moisture, or is brought from various degrees of humidity and delivered to the burners at a uniformly maintained degree of dryness. The air is supplied to the furnace under pressure from a blower or pump 23.

The temperature of the tank is subject to regulation, but whether the delivered air is moderately cooled or very cold, it is delivered to the burners without fluctuation of temperature, to secure a uniform rate of flow through the burners. For this purpose the dried air, whether cool or very cold as it is delivered from the header 14, is brought to a constant uniform tem- I perature, preparatory to being fed to the burners. The preferred manner of maintaining such uniformity is to heat the dried air to the temperature of the room in which the apparatus is being employed, thereby taking advantage of the fact that the temperature of the room usually remains quite steady for an indefinite time.

It has been seen that in the tank is water, oil or other suitable refrigerating fluid 16. If the temperature of the air in the drying coil is to be reduced below water-freezing point, a mixture of oil with suitable refrigerating ingredients can be used. The temperature of the bath in the tank may be reduced to any desired point in any suitable manner, to control the humidity or dryness of the delivered air. The temperature 136 is controlled from the refrigerating source. The air may be treated to reduce humidity to any point that is required. The fluid in the tank maintains the proper temperature for which the apparatus is set. It condenses all of the humid 13" ity which exists above the required point, and such excess or surplus, however it may fluctuate, is drained off by means of the water trap.

The delivery header 14 is wholly immersed in the refrigerating bath, but its delivery end is 14g turned upwardly and detachably jointed at 24 to the header 25 of a second principal air coil, which is exposed to the temperature of the room, and is used to warm the dried air uniformly. This warming coil includes also a delivery header 26, this header being connected by

pipes

27, 28, 29, resembling the coils 20, 20 19, and of about the same dimensions, and dividing the air into numerous streams for warming it to room temperature. 1' 0 ur ce h ving one r more ets f burn rs, for

cu ately giving. med h atines to class radio ube 35,. ex mpl Th bu ners ar indiated at 6, ndare upplied with as mixed,

ith h ura ly drie and warmed air. The m ing of the gas and he air f r in. the. urne s, an be f c ed in a mixer, ontrol i he suppl f r in due p opo tion t as for the tumors is in cated d etsrammath cally by valves 3'7. I

The temp ture the tan cate b m n o n e ect ical indicator 57, con-.

e d o a ment' 8 ubm r d in th tank. Th c g i he liqu may be resulated'hy any uitab means, shown ia rammatically as. a

lv 5 c ntrollin the new of coolin fluid th ug -an i 0 imm rsed in the upp r por ion f he a h-v ,Any ui bl tank-c olin coil or means under any suitable control may be provided for this purpose.

The glass making or forming machine is thus supplied with a mixture of fuel-gas and compressed air which maintains uniformity of heat at each of the various burners, the degree ofheat being different at different burners, if desired; but being maintained at an unfiuctuating point at each burner, so that, the operation of the glass-making machine can be successfully car-. ried out in the manner desired.- Further irregularities in the operation and eff ciency of the burners in glass-making and other machines, conceive, are due to moisture present in the gas itself, which is mixed with the compressed air on its way to the burners. Moisture in the gas is due to the use of water or vapor t, on sta e n its manufacture. in the as is helicvedto. be an. elementcondu ing to inefficiency at the burners, and this humidity may also fluctuate, being dependent upon the heat at certain stages of gas manufacture; hot gas absorbing more of the moisture from the water or steam than cooler gas.

To overcome this part of the general burner difiiculty, I pass the gas through a coil which is kept at a low tomperature, say 35 degrees or there-abouts, whereby the gas is deprived of its humidity, and the moisture is collected. and dis-. charged through a water-trap. The gas is pref.- erably also allowed to rise to roomstemperature, say 60. or 7Q degrees, before it ismixed with the compresse airon itsway to the burners. The

temperature of the gas-drying coil. (and also'the.

air-cooling coil) may be kept at a desired cold point; automatically by means of thermostatic regulators; and. each may be also manually adjustable the same as the air-drying coil. 'The two coils-maybe placed in the samecooling ta-nk' if desired. p

When the gas is to be dried, it may be carried through. a main 38.to an intake pipe 39 arranged. in the same tank 15 as the air-cooling coil. The gas-cooling coil. may comprise a bottom header- 40, conneetedby alser'ies of return sub-t coils to an upperheader 41, said sub-coils ini- .cluding lower and upper: horizontal pipes 42,

Accurate k may bi; ndi- The humidity 4 connected by a vertical pipe 44. The moisure c ndensed from the gas finds its way down iwthfl hbader 40, and hence down through a D 9 45, connected thereto, and discharges hrousha wster trap 46. The gas-cooling coil osto deal with less volume than does the aircoc ins coi and there ore may be nested within he a r-cooling coil the tank, as illustrated, so as to economize tank-space,

Attached to. the delivery portion of the disharge gas-header 41 istheintckc 4a of a gaswarming coil. whereby the dried gas is broughtp to room t mnerature. or heated to thesame point as the dried. air. This gas-warmin oil cludes ower and

upper headers

49 and 50, conhosted bysubwc ls 51. similar to 41, 42, 44, to he upper header 50, which leads to a main 53 om which as-supply. pipes 54 branch to the urners 36, I A sea and air mixer is shown diarammatically at 55, a d the supp y. of gas and air may be con rolled. by valves 56 or otherwise. he m xing of the gas and air may be automatially pronortionedas disclosed n patents here- Qfores n-nt d to myself. and to G. F. Machlet.

Variati ns may be rasortedto within the score f the invention, and portions of the improve-..

dried air under. pressure, and means to direct a.

jet of the burning mixture againstthe glass article being treated.

2. An apparatus for softening. each of an in- 1 definite succession of glass. articles with heat maintained with precise uniformity at a specific point for a specific interval, without endangering the glass, including means for compressing and cooling fuel gasto deprive it of moisture, means for cooling and compressing air to deprive it of moisture, adjustable meansbeing provided for regulating the coldness of the chilledair, thereby controlling the humidity of the delivered air, for

mixture with the gas, means for warming both the i dried, compressed air and the dried gas to a uniformly maintained maintained degree, means for mixing the dried and warmed gas with the dried and warmed air, and means to direct a jet of the burning mixture against the glass article being treated.

8. An apparatus for softening. each of an inand the dried air to a uniform warm temperature, I.

- means for-mixing the dried gas with the dried air under pressure, and means to direct a jet of the burningmixture against the glass article being treated.

'4. ABunsen-burner apparatus for maintaining heat precisely at a uniform point, including an.

air-compressor, a coil through 'which'the 'compressed air flows, a cooling tank in which the. coil is immersed in refrigeratingliquid, whereby the airyis reduced to thedesired degree of humidity,

its?

a second coil connected between the first coil and the Bunsen-burner, to warm the cold and dried air, separate means for cooling fuel gas coming in from a source of supply under pressure, thereby to deprive the gas of moisture, and means to mix the dried gas with the dried air, for delivery to the Bunsen-burner said gas-cooling means in the form of a coil arranged in the same tank with the air-cooling coil.

5. A Bunsen-burner apparatus for maintaining heat precisely at a uniform point, including burners, an air-compressor, a coil through which the compressed air flows, a cooling tank in which the coil is immersed in refrigerating liquid, whereby the air is reduced to the desired degree of humidity, a second coil connected between the first coil and the Bunsen-burner, to warm the cold and dried air, separate means for cooling fuel gas coming in from a source of supply under pressure, thereby to deprive the gas of moisture, means to mix the dried gas with the dried air, for delivery to the Bunsemburner, said gas-cooling means in the form of a coil arranged in, the same tank with the air-cooling coil, and nested within the air-cooling coil, and warming coils for the air and gas, the gas-coil being nested within the air-warming coil.

6. The process of heating in rotation each of a succession of glass bulbs with precise uniformity at a specific heat for a specific interval, only sufficient to soften them individually, and without endangering the glass, preparatory to further treatment thereof, including cooling atmospheric air under pressure in confinement to d prive it substantially of all of its moisture, warming the driedair under confinement to uniformly maintained work-room temperature, mixing the dried and warmed air with fuel gas, burning the mix-- ture in the form of a jet, and exposing the glass burn to said jet for precisely the specified interval.

7, The process of heating a glass bulb with precise uniformity at a specific heat for a specific interval to soften it, without endan the glass, preparatory to further treatment thereof, inciuding cooling both atmospheric air and fuel gas separately in confinement to deprive them substantially of all of their moisture, warming the dried air under confinement to uniformly maintained work roorn temperature, warming the dried gas to substantially the same degree as the dried and warmed air, mixing the dried and warmed air with the dried and w med fuel gas, burning the mixture in the form of jet, and exposing the glass bulb to jet for precisely the specified interval.

In an apparatus for automatic manufacture of glass articles, means for softening each of a succession of glass articles Without endangering the glass preparatory to completing its facture, said softening means including a regulatable Bunsen gas-andto direct a jet of flame against each of the successive articles to be softened, and means to ma l ain the heat of the jet with precise uniformity at its regulated point for the specific interval during which each article is exposed by the automatic apparatus to the of the jet, said uniform heatmaintaining means incl ding a supply of gas, and an air desiccator and compressor having means to mix the desiccated with. the fuel gas under pressure, to prevent consumption fluctuation-- producing moisture in the jet.

9. In an apparatus for automatic manufacture of glass articles, means for softening each of a succession of glass articles without endangering the glass preparatory to completing its manufacture, said softening means including a regulatable Bunsen gas-and-air burner to direct a jet of flame against each of the successive glass articles to be softened, and means to maintain the heat of he jet with precise uniformity at its regulated point for the specific interval during which each article is exposed by the automatic apparatus to the'heat of the jet, said uniform heat-maintaining means including a supply of gas, an air-compressor, means for chilling atmospheric air to deprive it of humidity, means for regulating the coldness of the chilled air and thereby regulating the humidity of the delivered air for mixture with gas, and means for mixing the dried and compressed air with the gas, to prevent consumption of fluctuation-producing moisture in the jet.

10. In an apparatus for automatic manufacture of glass articles, means for softening each of a succession of glass articles without endangering the glass preparatory to completing its manufacture, said softening" means including a regulatable Bunsen gas-and-air burner to direct a jet of flame against each of the successive glass articles to softened, and means to maintain the heat of the jet with precise uniformity at its regulated point for the specific interval during which cach'article'is exposed by the automatic apparatus heat of the jet, said uniform heatinaintaininmeans including a supply of gas, an d ier compressor, means for warming the compressed, chilled and dried air to the temp ature of the work-roorn and maintaining it formly such temperature, and means to mix the unnorrily dried, compressed and uniformly warmed with the fuel gas, to prevent consumption of fluctuation-producing moisture in the jet.

11. In apparatus for automatic manufacture of glass articles, means for softening each of a su'ccession'of glass articles without endangering the lass preparatory to completing its manufacture, said softening means including a regulatabl Bunsen gas-and-air burner to direct a jet of flame against each of the successive glass articles to be softened, and means to maintain the heat of the jet with precise uniformity at its regu ted for the specific interval during which each article is exposed by the automatic apparatus to the heat of jet, said uniform heat-maintaining means includ 1g a supply of gas, an airdrier including chilling coil, an air-compressor, means, including a warming coil connected to chilling coil and exposed to work-room temperature, for Warming the chilled, dried and compressed o ttemperature of the work-room maintaining it uniformly at such temperature, and means for mixing the compressed, uniformly dried and uniformly warmed air with the fuel gas, for delivery to the Bunsen burner, to prevent consumption of fluctuation-producing moisture in the jet.

12. In an apparatus for automatic manufacture of glass articles, means for softening each of a succession of glass articles without endangering the glass preparatory to completing its manufacture, said softening means including a regulatalole Bunsen gas-and-air burner to direct a jet of flame against each of the successive glass articles to be softened, and means to maintain the heat of the jet with precise uniformity at its regulated point for the specific interval during which each article is exposed by the automatic apparatus to the heat of the jet, said uniform heat-maintaining means including a supply of gas, an air-compressor, a coil through which the compressed air fiows, a cooling tank in which the air is immersed in the refrigerating liquid whereby the air is dried, a second coil connected to the first coil, for warming the compressed and dried air to a predetermined uniform degree, and means connected to the second coil to mix the uniformly dried, compressed and uniformly warmed air with the fuel gas, for delivery to the Bunsen burner, to prevent consumption of fluctuation-producing moisture in the jet.

13. In an apparatus for automatic manufacture of glass articles, means for softening each of a succession of glass articles without endangering the glass preparatory to completing its manufacture, said softening means including a regulatable Bunsen gas-and-air burner to direct a jet of flame against each of the successive glass articles to be softened, and means to maintain the heat of the jet with precise uniformity at its regulated point for the specific interval during which each article is exposed by the automatic apparatus to the heat of the jet, said uniform heat-maintaining means including a supply of gas, an air-compressor, a coil through which the compressed air flows, a cooling tank in which the air is immersed in the refrigerating liquid whereby the air is dried, means for regulating the temperature of the refrigerating liquid in the tank, a second coil connected to the first coil, for warming the compressed and d ied air to a predetermined uniform degree, and means connected to the second coil to mix the uniformly dried, compressed and uniformly warmed air with the fuel gas, for delivery to the Bunsen burner, to prevent consumption of fluctuationproducing moisture in the jet.

14. In an apparatus for automatic manufacture of glass articles, means for softening each of a succession of glass articles without endangering the glass preparatory to completing its manufacture, said softening means including a regulatable Bunsen gas-andair burner to direct a jet of fiame against each of the successive glass articles to be softened, and means to maintain the heat of the jet with precise uniformity at its regulated point for the specific interval during which each article is exposed by the automatic apparatus to the heat of the jet, said uniform heat-maintaining means including a supply of gas, an air-compressor, a coil through which the compressed air flows, said coil including numerous sub-coils for dividing up the stream of air, a cooling tank in which the air is immersed in the refrigerating liquid, a second coil connected to said cooling coil for warming the cold and dried air to uniform work-room temperature, and means for mixing the uniformly dried, com pressed and uniformly warmed air with the fuel gas, for delivery to the Bunsen burner, to pr vent consumption of fluctuation-producing moisture in the jet.

15. In an apparatus for automatic manufacture of glass articles, means for softening each of a succession of glass articles without. endangering the glass preparatory to compieting its manufacture, said softening means including a regulatable Bunsen gas-and-air burner to di est a jet of flame against each of the succes ive glass articles to be softened, and means to maintain the heat of the jet with precise uniformity at its regulated point for the specific interval during which each article is exposed by the automatic apparatus to the heat of the jet, said uniform heat-maintaining means including a supply of gas, an air-compressor, a coil through which the compressed air flows, said coil including numerous sub-coils for dividing up the stream of air, a cooling tank in which the air is immersed in the refrigerating liquid, means for regulating the temperature of the liquid in the tank, a second coil connected to said cooling coil for warming the cold and dried air to uniform work-room temperature, and means for mixing the uniformly dried, compressed and uniformly warmed air with the fuel gas, for delivery to the Bunsen burner, to prevent consumption of fluctuation-producing moisture in the jet.

16. The process of softening a quick succession of unfinished delicate glass vacuum bulbs by reheating them uniformly to a fixed predetermined degree, preparatory to finishing them, including the step of exposing each bulb for a minute precisely pro-measured interval to the flame of a Bunsen burner which is maintained at a uniform predetermined heat by burning therein fuel gas mixed with atmospheric air which has been subjected to the process of extracting the moisture therefrom preparatory to heating the bulbs.

17. The process of softening a quick succession of unfinished delicate glass vacuum bulbs by reheating them uniformly to a fixed predetermined degree, preparatory to finishing them, including the step of exposing each bulb for a minute precisely pro-measured interval to the flame of a Bunsen burner which is maintained at a uniform predetermined heat by burning therein fuel gas which has been subjected to the process of extracting the moisture therefrom, mixed with atmospheric air which has been separately subjected to the process of extracting the moisture therefrom preparatory to heating the bulbs.

13. The process of softening a quick succession of unfinished delicate glass vacuum bulbs by reheating them uniformly to a fixed predetermined degree, preparatory to finishing them, including the step of exposing each bulb for a minute precisely pre-measured interval to the flame of a Bunsen burner which is maintained at a uniform predetermined heat by burning therein fuel gas mixed with atmospheric air which has been subjected to the following steps preparatory to heating the bulbs, namely, cooling the air under pressure in confinement to extract substantially all of its moisture, and then warming the dried air under confinement to uniformly maintained work-room temperature.

19. The process of softening a quick succession of unfinished delicate glass vacuum bulbs by reheating them uniformly to a fixed predetermined degree, preparatory to finishing them, including the step of exposing each bulb for a minute precisely pro-measured interval to the flame of a Bunsen burner which is maintained at a uniform predetermined heat by burning therein fuel gas mixed with atmospheric air which gas and air (preparatory to being fed to the burner) have been cooled separately in confinement to deprive 1*,

them of their moisture, the dried air having been warmed under confinement to uniformly maintained work-room temperature, the dried gas having been warmed to substantially the same degree as the dried and warmed air, and the dried and warmed air having been mixed with the dried and warmed fuel gas.

ADOLPH W. MACI-ILET.