US2542680A - Blast furnace stove - Google Patents

Description

Feb. 20, 1951 s. P. KINNEY ETAL 2,542,680

BLAST FURNACE s'rovE Filed Jan. 15, 1945 5 Sheets-Sheet 2 Feb. 20, 1951 s. P. KINNEY ETAI.y 2,542,680

BLAST FURNACE sTovE Filed Jan. 15, 1945 s sheets-sheet s lNvENToRs l, 62 Seh/Unef, fz'nnjy Louis H ar-Widt Patented Feb. Z0, 1951 UNITED ISTATES PATENT OFFICE BLAST FURNACE STO'V'E Application January 15, 1945,"Serial-Noil'l' 7 Claims.

This invention relates toblast furnace stoves,

duced through a Yburner at'fthe` bottom :of the flue, and the burning gases of combustion. travel up the flue to the top. The remaincl'er'of the interior of the stove is ll'e'd-with checker .brick and the hot combustion gasesA travel` downwardly through this checker vforlgiheatngf '1'.lie-c11ecker` brick. When the interior of the .fstovexha's' become sufficiently hot, combustion is'stopped'and air is blown in reverse direction through .the-

stove, and the air which is thusheatedgis used in operatingV the blastfurnace.

The checker brick: is supportedon a stove-bot;- tom which is elevatedabove the actualbottom-iof the stove. This bottom comprises vertical 'supporting columns of structural metal which-sup'- port horizontallyextending girders. These girders in turn support'I 'a metal grid structure on which the superimposed'column of checker'brick is carried. This elevated stove bottom is necessary to'provide an air'chamberunder the column of checker brick. A stackconnectionleads'ifrom this chamber, and whenithe stove"` is operating on the air heating or blast cycle theair to bei heated is introduced through the stack'pipe' into :this chamber.

When the stove .is operatingfonV y'the heating cycle, the lhot'gases of'combustion passing down l'lhrough` the checker brick' andenteringthe cham'- ber: below the-bottom are sti-1l ata very highitemh perature, and temperatures are: encountered/at the bottom of the stove which are above "the critical temperaturek of thestructuralfusteel, thus weakening the steel and rendering .itsfperforme- -ance unpredictable. The weightv of `vthe'isuper imposed column of checkerbrick is verysubLv stantial, andrif any part oflthe .bottom-fails the checker brick 'shifts and .thefstov'e'iis imepaired if not rendered useless. One `oi'th'eefm'ost` seriousy diiijculties Vin thexopera'tionhoi 'blast iur-- nace/stovesis due toy bottom: failure. Whereas; their expected life is twenty years, they will sometimes fail inta comparativelyiewtmonths or` thousand v($80,000.0o);collars, :but-.contratantes (Cl. 26S-15.)

the blastinmate may be impaired when: the stovehas to be taken `out of service for repairs.

VVlflereto'ore theonlyway to guard"againstTailure of thestove bottom has'ben to `use sections o'fl extra heavy rmx-ital,y many times heavier"than that 'theoretically required to .fs'a'ely carry 'the load.-

Accordingto the present invention protectionis provided against failurerf thebottm-bynuid coolingi, 'as 'for' example by" 'the' provisiiiA 'oi ducts alongv or constituting a part of" the structure. Hence, 'they may bekep't, during the operatioifflot ther'ifurnacefeven rfrvery longv periods of 'time on a heating-cycle, at `a temperature such'as to avoid danger to the bottom. VThein'veii'tix) the? 'cbt'mplates the provision 0f,a"15rtc`l1t'e arrangement-.in the vstove -so that Ywhere water is :usedfas 'thef cooling-medium accumulations of water initheibottom'of the stove may be-avoid-edf. The invention further contemplates an arrange-l ment wherebythe f-unetici-1mg'ofthe*cooliiigrsysi tem may ybe properly' checkedv and supervised and"- Warnigfgiveh ofthe 'failure in a-'I'lypart of the system.

The:-irlve'ntion may vbefi'nore fully understood'- by"referencetov the `accompanying drawings, iii which: n

Figure 1`l is" a verticallsction, more' fanless coii= ventional, through va-blast furnacesto've-Offthe" type' toy -vvhichl the: present" invention pertaihs Figure is a detail view partly i'nsectio'riffaiid'f partly iii-elevation showing on a larger Scalea portion of' thefstove bottom;

Figure 2fi"1isfafsection taken on line II-lI--of' Figure 2; Y

Figure 3` isa view partly in vsectionandpartly in elevation at right angles to Figure; 2;`

VFigure 4 lis va more or less schematic' YsectionirrtlreL plane' 'offline y13VIV- of Figure 1,v showingtheiconnectionsfor water cooling the-columns;

:Figure 5i isa more yorless schematicview show: ing a top plan view of the for cooling-i them ing kagainst vthe accumulation ofV the waterv initl'e'1 stoveibcttom and `for drainingA the*waterthere from;

yFigure s isa detaiiview showing ragportioiror the discharge line:A or any one: ofv the water cool#l inglcircuits'tojgive a" visible indication 'of the tu failureoffthecoolingfcircuit or overheating;

girders with provision tional character, showing a plurality ofY the'g'rd' Figure 9 is a circuit diagram showing an electric protective system for Warning against the overheating of any individual part of the assembly;

Figure is a longitudinal Vertical section of a modified form of column;

Figure 11 is a transverse section in the plane of line XI-XI of Figure 10; and

Figure 12 is a fragmentary view similar to Figure 3 showing a modied cooling arrangement.

Referring first to Figure 1, the cylindrical shell of the stove is designated 2, and it is of conventional construction with a vertical flue on the interior thereof constituting the combustion a number of grid sections 1, these grid sections having closelyT spaced horizontal bars connected together, the grids covering substantially the entire interior of the stove in the space beneath the checker brick. These grids are laid in endto-end and side-by-side relation and are supported on horizontal girders 8. The horizontal girders in turn are carried on vertical supports 9 which rest on the bottom foundation of the stove, the bottom foundation being designated generally as I0. It is usually covered with refractory bricks. There is a stack pipe 4a leading from the chamber under the grids I. A hot blast olitake pipe is indicated at 4b.

, So much of the structure as has' heretofore been described is conventional. According to the present invention the grids "I, girders 8, and columns 9 are formed of metal and are water cooled.

...The construction of these elements according to the present invention is best shown in Figures 2, 2a and 3. Eachl column 9 is a rolled structural Hsection. At the bottom of the section is a base plate II and at the top of the column is a cap plate I2. Welded to the anges of the H sections are plates I3, these plates also being welded at their tops and bottoms to the cap and base plates I2 and II respectively. Thus there is provided two closed ducts I 4 and I5, one on each sideV of the web of the column. Adjacent its 'lower end the web is perforated as indicated at i6 to permit the now of water or other cooling fluid from one passage to the other. A water intake pipe is welded into the plate I3 on one side of the column anda water outlet pipe is welded into the' The cap plate I2 at the top of the column has upstanding flanges 12a thereon, and the girders 8 which extend horizontally rest on the cap plates I2 and are confined against lateral movement by the flanges IZa. The girders may also be formed rolled metal H sections, and plates 8a and 8b are welded to the flanges thereof to form two horizontally extending ducts I9 and I9a respectively.

The ends of these ducts are closed by plates Se welded across the ends of the girders. A water inlet pipe is welded into one of the plates 8d and a water outlet pipe 2I is welded into the plate 8b. The web of the section is perforated as indicated at 22 at that end of the section which is remote from the inlet and outlet pipes so that the Water travels lengthwise at one side of the girder, through the holes 22, and lengthwise along the other side of the girder through the duct 20 thereof through the outlet pipe 2 I` Customarily the bars constituting the grids l are solid bars, but according to the present invention these bars are comprised of similar shaped sections la set edgewise with a plate Ib Welded to the flanges thereof to form a longitudinally extending duct lc. At each end of the channel the duct is closed by a plate 1d which is Welded thereto. A number of parallel bars or channels formed in this manner constitute a unit, and all of the bars of the unit may be connected by water pipes 23, which are alternately located at opposite ends of the bars, as best shown in Figure 6. There is a water inlet connection 24 at the end of one ofy the outside bars of the section, and an outlet pipe 25 at the end of the other outside bar of the section. Between the which may conveniently be used so that all of:

the columns are connected in parallel with a common water inlet connection, and are also connected in parallel with a common water outlet connection. In this ligure, the main water inlet pipe is designated 26. It has branches 25d that lead to the intake pipe I'l of the several columns. The water outlet main is designated 2l and it has branches 28 that connect to the outlet connections I8. Preferably there are no unions or pipe connections in the system, it being preferred to join all communicating pipes by welding.v

While it is of course possible to connect one or more of the columns in series so that the water will flow from one into the next, it is preferred that they all be connected in parallel as this makes detection of any failure easier to locate. Likewise, all of the inlet pipes 2li for the girders are connected through pipe 29 to a main water supply main 30, and the outlet pipes 2 Ia are connected to an outlet manifold or main 3I. In the same manner, there is a single source of water supply 32 connected through connections 2d with the several grid unit-s, as shown in Figure 6, and the top pipes 25 of all of the grid units are connected through pipes 35 with an outlet main 3B. The water circulating systems for the columns, girders and gridaare preferably all connected in parallel, although here again it might be possible to connect them in series, but being connected in parallel, location of a failure may be detected more quickly.

. Each outlet main prefer-ably terminates in some kind of a visible flow indicator of the type illustrated in Figure 8 in which A designates the terminal of one of the outlet mains and B designates a spaced funnel-shaped collector into nected, in a proper manner. If the water does not flow', or if onlyA steam isowing, that-enden or operator may see itimmediately. Since there, .is-onexof these sight flow devices for the column system, another for the vgirder system, and `a third forl the grid system, 'the operators may' know. immediately if anyone of the systems is notv properly working.

Inorder to give a moreaccurate indicationoi just where there is a failure of the water circulation, electrical indicating devices employing thermostats or thermocouples may also be used. This is illustrated in Figure'9.

In Figure 9, there is shown one post or column unit, one girder unit and a grid unit. Each has a thermostat or thermocouple, i. e., a heat responsive circuit closer, applied thereto, as indicated schematically at 3l, 38 and 39.respeotively. Each is in circuit, through a separate indicator 31a., 38a and 39a, respectively, which may be signal lamps, with a source oi current 34. There may be any desired number of such Yindicating'means in .the `cooled supporting system, `although .itV is not normally deemed necessary to have an indicator `on every unit. An increase in temperature is by such means, indicatedfby alight. or other indicator and the regionoff such increase noted.

Unbeknown to the operator, a leak might occur in thesystem resulting in an undesirable accumulation of water in the bottom ofthe stove. To guard against this, the iloor l ofthe chamber maybesloped toward a sump 40 in which is a oat 4I and from which leads a drain 42 with a valve 43, outside the stove, therein. If there is a leak, water will flow into the sump, and raise the iloat.

tifies the tender of the leak. The tender may then open the valve 43, or such operation could be eiected automatically by the iloat controlled electric circuit.

Instead of using rolled structural columns as described, heavy tubular columns may be used, as shown in Figures l0 and l1, wherein the outer tube is the main column with a base 5l and a cap 52. It is of heavy metal. Inside the tubular column is a smaller tubular column 53, preferably co-extensive in height with 5B so as to aid in carrying the load. There is a water inlet nipple 54 leading to the bottom of tube 53 and openings 55 allow the water to flow into column 5E! to outlet 5B at the base thereof.

In the foregoing description we have indicated that water is used as the cooling medium, but it will be understood that any other suitable fluid may be circulated through the ducts in lieu of water, and the term water is used to include equivalent cooling of fluids, including air or other liquids or gases.

In the foregoing description we have also described the circulating system as being a closed system, this being the most desirable. However, it is not necessary that the system be enclosed, as it is within the contemplation of our invention that when the stove is on the heating cycle, cooling iiuid may be injected into the lower part of the stove adjacent the support to cool the supporting structures and simultaneously .reduce the temperature of the gases as they move toward the stack outlet. This is illustrated, for example, in Figure 12 where the grids, designated Ell, supported on the girders 5l, carried on columns 62, are provided with pipes B3 extending therealong. These pipes have small openings therein for projecting streams of cooling fluid directly against The float operates a circuit closer 44 to an alarm or signal 45, whichnoiii section .and being.' .directly iunder the checker' brick. coumnare more. ksusceptible to damage thanfanyothercpart of the bottom. Bysintroe' ducing cooling/fluid in this manner-directly into. the lowerpart of the. stove, these `grids are-:cooled and the volume of gases which'ows on down around the girderszi` l` and `columnsdz has its temperature somewhat reduced, depending ofA course upon the..amount of fluid which is introduced throughthe pipes6f3. 1f therfluid used forfcoolingvthe bottomfstructure be water, a consider-.. able amount ofheat `will be absorbed as latent heat ofl vaporization. --Also, suflicient water can be introduced so that some of it will'flow down over the girders 5| and column 62 to cool them. When the fluid is'introdu'ced in the manner described'in connection with4 Figure l2, it is lintroduced only when 4the stove is on a heating cycle, andi it'is cut oif Yas. soon as the blowing vcycle is started. The arrange-ment shown in Figure '7 is particularly desirable with the arrangement shown in Figure l2, when the cooling iluid is Water, because any large accumulations of water may be drained olf before the blowing cyclestarts.

Whilefwe'have illustrated and described cer-j tainembodiments of our invention, it will be un-` derstood thatthis is by way of illustration, and

that Avarious changes and/modifications may .be made within the contemplation of our'invention and under the Scope of 'the following claims. Also, rwhile we have shown a stove in `which the columns-girdersfand lgrids are entirelyy of metal;- it will be understood that our invention is also' applicable to stoves in which. combinations of metal and Amasonry are used.

We claim: Y

l. A blast furnace stove having a checkersupporting structure therein comprised of columns, girders on the columns, grids on the girders, said codlumns, girders and grids being formed of hollow sections to provide water circulating ducts therethrough, means for supplying water to said sections. means for discharging water from said sections, all of the columns having a common discharge system, all of the girders having a common discharge system, and all of the grids having a common discharge system, the several discharge systems having means visible exteriorlv of the stove for indicating an abnormal water condition in the system.

2. A blast furnace stove having a checkersupporting structure therein comprised of columns, girders on the columns, grids on the girders, said columns, girders and grids being formed of hollow sections to provide water circulating ducts therethrough, meansfor supplying water to said sections, means for discharging water from said sections, all of the columns having a common discharge system, all of the girders having a common discharge system, and all of the grids having a common discharge system, the several discharge systems having means visible exteriorly of the stove for indicating an abnormal water condition in the system, said means comprising a sight discharge device.

3. A blast furnace stove having a water-cooled metal bottom structure for supporting the checker work, a oor under the water-cooled bottom structure, means on the iloor for collecting and draining away leakage water which may accumulate, and means for signalling the presence of accumulated leakage water at they 4. A blast furnace stove having a Water-cooled bottom structure for supporting a superimposed column of checker brick, means for indicating a leakage in said Water-cooled bottom structure, said means including a sump in the floor of the stove, a oat in said sump, and electric signalling means controlled by said float.

5. A blast furnace stove having a metal structure for supporting a column of checker brick therein, said structure being formed of hollow metallic sections, and means for circulating cooling fluid through said sections, heat responsive means carried on some of said sections, and signal means externally of the stove controlled by said heat responsive means.

6. A blast furnace stove having a bottom for supporting the checker brick therein, said bottom comprising columns, girders supported on the columns, and a plurality of grid sections supported on the girders, the columns, girders and grid sections being formed to provide Watercirculating ducts therealong, and a water supply system connected in parallel with all of the columns, a water supply system connected in parallel with all of the girders, and a third water supply system connected in parallel with all of the grid sections, and a discharge system connected in parallel with all of said columns and a discharge system connected in parallel with all of the girders, and a third water discharge system connected in parallel with all o the grid sections, said parallel systems enabling any failure to be readily detected and blocked oif and subsequently rejoined.

i7. A blast furnace stove comprising 'a vertically-extending housing having a column of checker brick therein with a chamber therebe- CII 8` neath through which hot gases'flow after leaving the column of checker brick, a supporting structure for the checker brick located in said chamberr and exposed to the hot gases which ow through the chamber comprising a horizontally-r extending grid, means for cooling the grid, horizontally-extending girders supporting the grid, means for cooling the girders and vertically extending columns supporting the girders, and means for cooling the columns.

SELWYNE P. KINNEY. J LOUIS M. HAR'IWICK.

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

Y UNITED STATES PATENTS OTHER REFERENCES Pages 285-293 of Industrial Furnaces, by W.'

Trinks, vol. I, third edition, published by John Wiley & Sons, New York, N. Y., January 1944.

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