US45343A - Improvement in the - Google Patents

Description

PATENTED nme. 1864.

- v 1. REESE. APPLICATION 0? HOT BLAST 0 PUDDLING FURNACES.

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PATENTED DEC. 5,'1as4;

J. REESE. APPLICATION OF HOT BLAST T0 PUDDL'ING FURNACES.

inventor.-

be a full, clear, and exact description thereof,

UNITED STATES PATENT OFFICE,

JACOB REESE, OF PITTSBURG, PENNSYLVANIA.

lM-PROYEMENT IN THE APPLICATION OF, HOT-BLAST T0 PUDQLlNG-FURNACES.

Specification forming part of Letters Patent No. 45,343, dated December 6, 1864.

To all whom it may conc'ernr; v Be it known that I, J neon Rnrlsn, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in the Application of Hot- Blast to Puddling, Boiling, and Heating Furnaces and I do hereby declare the following to reference being had to the annexed drawings,

- forming part of this specification, in Which Figure 1 is a side elevation of the exterior of a puddling-furnace, showingthe application of the apparatus which I employ in reducing myinvention to practicetgFig. 2 is a longitudinal sectional elevation of the pod dling-furnaee and blast apparatus shown'in' Fig.1. Fig, 3 is a transverse sectional elevation of the puddling-furnace through as m, Fig.

2. Fig.4 is a longitudinal horizontal section [of the fan-case of the fan eniployed'for creating the draft.

In the several figures like letters of reference denote similar parts of the furnace and apparatus.

In puddling, boiling, and heating furnaces for the manufacture of iron there is an enormous waste of heat, and consequently of fuel.

This is a well-known fact, and arises from the theheated air and products of combustion from the fire is ordinarily effected by raising the damper; but this admits atmospheric air into the working-chamber,which, passing over the iron, oxidizes it. If, to prevent this injurious effect, the damper is closed, the combustion of the fuel in the fire-chamber is retarded and'the heat becomes too low. As the length of the working-chamber is but five feet, or thereabout, the heated air, gases, and flame pass very rapidlybeyo'nd the working-chamber into the flue or stack, and thence out into the open air, and are lost. 7 of the heat is utilized. About fifteen per cent. is lost by radiation through the iron, brickwork, &c., of the furnace, and seventy-five per cent, at least, passes up the stack. Although the stack is about forty-seven feet in height,

About ten per cent. only the heat is so great at its mouth that the gases,

&c., pass out in a vivid flame, and theloss of.

heat cannot be checked or reduced by shutting down the damper on top of the stack, as t that would lower-the heat of the furnace and reduce thedraft, causing the heated air and gases/to pass over the iron so slowly as to impart to it less of their heat than if they traveled more rapidly. The enormous waste of heat consequent on the necessarily rapid passage of the-heated air and products of com bustion from the fire-chamber has prevented the use of hot-blast to the puddling and boiling of iron, which, I believe, has never been attempted before; but by the plan which I have invented, as hereinafter described, of causing the waste heat, heated air, gases,and other products of combustion which pass from the puddling-chamber to circulate through the furnace, impelled in rapid-circuit by a fan- 'blower, I am able not only to save and utilize a veiylarge percentage of heat previously.

lost, but also to apply a highly-heated blast directly to the process of puddling and boiling iron in l a puddling-furnace.

of the puddling-furnace, if charged with oxygen, would injure'(by oxidizing) the iron, and if deprived of oxygen would not keep up the heat of the furnace by supporting the combus tion of the fuel; but this difiiculty I overcome by supplying the requisite amount of oxygen to the circulating current after it leaves the pnddling-chamber and before it enters the fire, and by passing it then through the body of incandescent fuel in the fire-chamber I deoxidize the current, or at any rate deprive it of a large portion of its oxygen, and largely increase its heat, and thus fit it for its work in the puddling-chamber. If, asI believeto be the fact, I am thus enabled continually to return to the fire-chamber of the furnace a very large proportion of the seventy-five per cent. of heat otherwise lost, and also to save the large quantity of carbon which would otherwise passfofi as smoke, and to return the unconsuined gases, charged with oxygen to aid their combustion, into the fire-chamber, it is manifest that Imust effect a very great saving of fuel, as well asin a cheap and simple manner supply a hot and deoxidized (instead of a cold) blast to thepud- This circulating hot-blast, which passes first through (not 'merely, over) the rlire in the fire-chamber, and thence over the iron in the working-chamber:

dling, boiling, and-reheating furnaces for the manufacture-of iron. v I Y'Toenable others skilled in the art to make useof my improvement, I will proceed to describe itmore particularly, and the method z bieh I employ to carry it into practical efec a ,7 1

In the accompanying drawings, Fig. 1 represents the exterior, and Fig. 2 the interior, construction of a furnace for puddling iron.

The working-chamber a, in which the iron is puddled, and the stack 6 are constructed after the method generallyin use in western Pennsylvania. The fire-chamber c is'of the peculiarconstruction for which Ihave obtained Letters Patent dated Februaryfi,-1861. Below the level of the bed of the workingwhaniher the diameterof the fire-chamber isgradually reduced, the-sides sloping toward'each' other. No grate-bars are used; but the bottom is closed by an iron door, on which, in the bottom of the fire-chamber, is laid a bed of sand. An aperture or vent, e, near the bot- .tom, allows the melted clinker torunoff-as fast as it accumulates in the bottom of the fire-chamber. If preferred to allow the melted clinker to accumulate in the bottom .of the fire-chamber, this vent c is closed and another.

is opened at the line of the lower edge of the blast-opening f, which communicates with thefurnace a little below the level of the bottom of'the working-chamber a. This blast-flue) rises upward to the top of the furnace, where it communicates with the blast-pipe g. In the stack b, just" above the Zvelvetry, anopening is made, into which is inserted the blastpipe g, which passes horizontall to the fanblower l, andthenc'e downward communicate with the blast-flue g at the front end of the furnace. 1

The'blast-pipe g and the case 2 of the fanblower, being necessarily exposed to a very: high heat, are made of sheet-iron, and lined throughout internally with fire-clay. In the horizontal part of the blast-pipe 9, not far from the stack,-is a steam-injector, 0', being a pipe inserted into' the blast-pipe with its :c'nrved extremity turned toward the fan in the direction of the current. This steam-injector communicates with any. steam-generator, and through it steam is let into the blast-' pipe. Beyond this point, and near to the fanblower, the blast-pipeg is enlarged, so as to allow for the expansion of the steam and the infiux'of atmospheric air through the air valve it without impeding the draft through the blast-pipe 9. From the blast-pipe g the air enters the fan-case Z, the shape of which may be seen by comparing Figs. 2, 3, and 4D In Fi' 2 a longitudinal vertical section is given, the section being, as usual, circular. In Fig. 4 a longitudinal horizontal section is given; in Fig. 3, a transverse vertical section. At the point x, Figs. 2, 4, the hot-blast enters a passage which conducts it (as seen by arrows in Fig. 4) to the openings yy at the center of the fan-case.

2, Figs. 2 and 4, is the interior of the fan- 'case, in which the fan revolves rapidly, driving the hot current down the blast-pipe g nto the fire-chamber c of thefurnace Thefan, being a suction-fan, draws the heated air, smoke, and gases from. the stack 1), with the steam and atmospheric air which enter the blast-pipe at i and k, into the fan-case, and thence send them in a strong blast down the pipe as just stated.

Although the fan is made of iron, it could not resist the strong heat of the blast passing through the fanrcase without some meahs ,of protection. For this purpose the arms at m and wings n n 'of the fan are made ho llow, and a."str(=.am of: cold water is kept con tinually through them. A pipe, 72, leading :water'from some more elevated point, enters thebearing of the hollow axis of the fan, the bearing breakingthe joint at t e point 'of connection of the pipe and hollow shaft, and pre venting the escape of water. The water thence passes along the'hollowaxis 'ofthe fan, along the arms in m, through the hollow wings n n, 1

' and thence along-the-arms m m onvthe farther side of the fan to the axisq', thence out at the esca'pepipe r. .,The hollow axis q f of .the fan is obstructed between-the arms m m, so as to prevent the water running through without reaching the extremities of the fan-Wings, The fan and its case may orroof of the puddling-furnace.

Having thus described the blast a'pparatufi and construction of furnace which I use,-I wilf. I

proceed to explain more fully its operation.

The heated air,unco nsumed gases, and" smoke which pass oil from the working-chafing her up the stack or chimney are prevented by .a damper at the top of the stackfrom' e'scaping in that'direction, but by means of the suction-fan are drawn off through the horizontal blast-pipeg, the fan-case Zbeing so eonstructed, as before described, as to admit nothing within it but what comes through the blast-- pipe. When the hot air,-gases, and smoke enter the pipe at its orifice in the stack, they are at a temperature usually of from 1, 800 to 2, 000 Fahrenheit, but, although intensely hot, are not calculated in. their present state to serve as a blast for a fire, for, having been almost,if not entirely, deprived of their oxygen, they would not materially aid in the combustion of the fuel in the furnace, which is not suppliedwith air from any other channel than the blast-pipe; g g and the blast-flue f. To supply the necessary oxygen a jet of steam is introduced through the steam-injector 'i into the blast-pipe g, which mixes with the hot current of gases, smoke, &c.,' and enters the fan-case, whence it is forced through the flue heit. this hot-blast enters the firemhel steam is decomposed, the oxygen uniting with be placed on the top carbonof the fuel, and the hydrogen'with the ually returned to the fire and there-consumed.

do I claim, broadly, heating a current of air sulphur and carbon, and forming a highlycombustible gas. If steam cannot be con-' veniently used,cold atmospheric air, may be introduced through the valve kinto the blastpipe 9, which will. unite with the contents of the blast-pipe, reducing their temperature,

but affording the requisite supply of oxygen. If desired, both. the steam-injector and air valve may be used at the same time. The airvalve should be so regulated astcradmit only about one-third as much air as the volume of gases, &c.', in the blast pipe 9. By these means'a constant circulationof heated gases,

smoke, &c.,is kept up, not unlike the circulation of the blood, in the body, the air-valve or steam-injector servingas the lungs to oxygenize the current.

No damage can accrue to the iron in the puddling-chamber by this process,as the oxygen is consumed in the fire-chamber, and the other gases are only those which have before passed over the iron, and which are contin- I do not claim as new the use of steam for supplying oxygen to promote combustion, nor

before introducing it into a fire-chamber or furnace; but I I What I do claim as my invention, and desire scribed.

-REESE, have hereunto set to secure by Letters Patent, is- I 1. Oreatingahotblastfor supplying the firechamber of puddling, boiling, and heating 1 furnaces, by' drawing the waste hot air, gases, and smoke, alter they'have passed over-the iron in the 'puddling-chambe'r, from the furnace- 2. The application tothe working-chamber of puddling, boiling, and heating furnaces of a hot-blast, consisting of the waste heated air, gases, and smoke drawn from the stack or chimney of the furnace, and,previous1y to entering the. working-chamber, deoxidized and highly heated by passage through the body of the fire in the furnace, substantially in the manner hereinbefore' described.

3,0onst1ucting a fan for hot-blast with hol low axlefarms, and wings, or any of them,for preventing the injurious action" of the intqlse heat by passing a current of cold water through the fan, substantially as hereinbefore de- In testimony whereof I, the said .noon

- JACOB REESE. In presence of- M. G. CUSHING,

A. S, NIcHoLsoN. Y

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