US1703517A - Blast furnace - Google Patents

Description

Feb. 26, 1929.J 1,703,517

J. P. DovEL BLAST FUR'NACE n, unam Feb. 26, 1929.

J. P. DOVEL BLAST FURNAC Filedy Nov. so, 1925 INVENTQR MMES R DOI/EL ATToRN Y Patented' Feb. 26,1929.

UNITED STATES PATENT OFFICE.

JAMES P. DOVEL, F BIRMINGHM, ALABAMA..

BLAST FURNAGE.

Applicatioaled November 30, 1925. Serial No. 72,108.

as well as of the furnace charge to the end that the blowing out of the furnace for relinin I or repairs to bosh or top will be practically e iminated, and that this furnace can be blown out and blown in at will without damage to any part, and when blown in can be worked at full capacity immediately.

My invention is more particularly concerned with'the construction and protection of the stack and its lining to the end that ideal operating conditions may be maintained for the maximum lengthy of time.

In the present practice, blast furnace stacks are provided with refractory linings often from 30 to 48 in thickness, the idea being that such very thick linings would resist .the

wear and deterioration longer and thus increase'the life of the linin I have found that such thick linings are 05j ec because they reduce the capacity and output of the furnace; and second, because they tendy to wear or deteriorate so as to provide substantially varying diameters from the furnace top to the bosh, the lining being often cut away near the top by abrasion from .the stock,

providing a top zone of enlarged irregularlyvariable diameter, below which is a zone in which-the lining is of full thickness below which is the maximum temperature zone in v which the lining is rapidly reduced in thickness so as to produce here a zone of irregularly-increasing diameter against which at its bottom, merging into the taper of the bosh, tends to raise the contracting zone of the bosh too hi h up into the body of the furnace. Un-

40 desira le operating conditions result from such deterioration of the lining, because the stock will tend to'hang or scaffold over the upper hump and it will reach the contracting zone of the upwardly extended bosh before it has completed its expansion and as a result it will again tend to hang or scaffold at this point. If the lining can be maintained relatively -thin and so protected that there will be negligible wear at any point, it will be at once obvious that the gradually expanding bore of the furnace will permit the stock to move down in the desired manner and, there tionable, first,

preserve substantially constant the thickness causes, without requiring any disturbance having been no appreciable wear of the lining at the upper end of the bosh, the bosh zone will remain constant and the stock will have completed its expansion and. have begun'its contraction due to melting, when it reaches the contracting bosh zone. It follows that the stock will move always const-antl ,and without hanging downwardly throug the stack,

so that the 'maximum output of the furnace can be obtained and the continuity of its operation will be very greatly extended over any existing practice.

' To obtain these ends I construct the furnace wall of an outer metallic shell having a4 relatively thin lining of refractory "material,- preferably not over 21 thick, I embed in this thin lining, throughout the maximum temperature belt .of the furnace, a series of closely associated cooling blocks suitably mounted on the shell and arranged in such relative relationship that the thin lining of the furnace is keptcool sufficiently to prevent its rapid deterioration. By reason` of the walls being cooled, as deterioration occurs, I have discovered that there is a building up or replacing of the lining from component elements of the furnace burden, which will in practice.

ofthe lining, and the uniform diameter of the furnace. To protect the top of the furnace shell where water cooling is, as a general rule undesirable, and to further reduce the cost of the furnace stack, I stop the refractory lining 'as close to the high temperature zone as it will be practical to use a metallic lining, and I re-l duce the diameter of the shell above this point,

providing internal wear plates readily demountable from the shell and connected thereto so as to permit of the insertion of a thin refractory lining between the wear plates and the shell. My experience'has disclosed that' these wear plates have practically indefinite life and with a very thin refractory lining will serve to protect the u per shell without requiring it be water cool and these lining plates are so mounted as to be readily replaceable, when necessary due to fracture or other 1N of the upper shell. y

My invention further comprises the novel details of construction and arrangements of parts, which vin-their preferred embodiments that they only are illustrated in the accompanying drawings which form a part of this Vspecification, and in which Fig. 1 is a view partly in elevation and partly in vertical cross-section of a blast furnace constructed in accordance with my invention.

Fig. 2 is an enlarged cross-sectional detail yof the bosh.

Fig. 3 is an enlarged cross-sectional view taken on the line 3 3 of Fig. 1, and showing a uadrant of the refractory lined portion of t e furnace. Fig. 4 is a cross-sectional view through the lining showing one of the cooling elements in' side elevation.

Fig. 5 is a front view ofthe cooling. block and its mounting frame; and

Fig. 6\ is a cross-sectional view taken on the line 6-6 of Fig. 5.

Fig. 7 is an enlarged cross-sectional View through the metal lined portion of the fur# nace; and

Figs. 8, 9 and 10 are respectively outside cross-sectional and inside Views of the shell and the demountable top panels which line the top of the furnace.

In the embodiment of my invention illustrated, I show a metallur ical blast furnace comprising the hearth 1, t e bosh 2, and the foundation 3 in which the columns 4 are mounted that support the mantle plate' upon which the furnace shell, above the bosh, rests. The usual bustle pipe 6 is suitably connected with the tuyres 7, the bosh having its lining 8 water cooled by the plates 9 set verticallyl about its upper portion and resting on the housing 10 for cooling blocks 10a. This housj ing rests on the tuyre jacket 10b which in turn rests on the hearth jacket 11. The upper ends of the several water-cooled plates 9 project up into the inwall of the furnace lining, resting loosely against the mantle plate 5 so are free to expand and contract vertically. The metallic jacket 12 of the furnace rises from the mantle plate 5 throughout that portion of the stack which is subjected to high temperatures, and this jacket has a relatively thin refractory lining 13 which is preferably of constant thickness throughout and which at its base merges into the bosh which itself has a very thin lining, as will be seen from the drawings. Throughout that part of the stack lining 13 which is subjected to the highest temperature and in the ordinar course of use tends to burn away and vwhich I shall hereafter briefly refer to as the hot zone of the lining, I interpose my improved wa-ter cooler protecting means for the lining which comprises closely associated cir-` cumferential rows of coolin blocks 14 set radially into the lining and sultabl mounted at their outer ends in frames 15 bo ted to the shell. These blocks are set in sta gered relation 'in the rows at different leve s and are spaced both in the same row and in adjacent rows on relatively close centers so as to maintain throughout this'hot zone a closely associated group of cooling blocks extending from the shell to points within-a few inches of the inside surface of the original lining. These blocks are suitably connected by a water circulating system of pipes so as to keep them well cooled and thus to maintain relatively cooled zones which overlap throughout the hot zone of the furnace lining.

The ing blocks 14 and the manner of mounting on the furnace is more clearly illustrated in Figs. 3 to 6, wherein it will appear that each block is a casting tapering in all directions from the outer end 16, the block being relatively wide and thin from top to bottom and cast with integral staggered webs 17 and 18 which provide a circuitous course for water entering through one of the inlet ports 19 and discharging through the other or outlet 'port 20. These ports are tapped with threads to receive the nipples 21 which connect each block with the circulation loops of piping 22 having a union joint 23 in each loop. Each block head 16 is cast with a pair of perforated lugs 24 for use in handling the blocks, and the block as a whole is adapted to fit with a tight taper fit into the frame 15 which is secured to the furnace jacket 12 by bolts 25 having headsf 26 set on the inside of the jacket before the lining 13 is applied, the outer threaded ends of the bolts being adapted to pass through the holes 27 provided in the border of the frame 15 to receive them. Nuts 28 on the bolts serve to detachably connect the frame to the shell, permitting the frame and block to be removed when necessary so that a damaged or injured block can be driven out of its frame, a new block and its frame readily reset'to the jacket with a minimum of labor and expense.

Water is supplied to the several series of connected cooling blocks from an upper header 29 by manifold distribution pipes 30 which supply the water to each coupled series, while manifold discharge pipes carry 0E and deliver the water to a waste trough 32.

Any vsuitable water piping-'system may be employed which will permit of the ready disconnection of the cooling blocks therewith when occasion requires. 1

The top of the furnace is provided with the usual hop er 33 having a bell 34 and immediately be ow the hopper is the outlet connection 35 to the down comer, not shown. The top of the furnace stack is made entirely of metaland comprises an outer jacket formed by connected sections 36 and an inner lining formed by metal wear plates 37. The plates 36 forming the lower belt of the outer jacket are provided with wide base flanges 38 which rest upon an angle bracket ring 39 secured to details of construction of these cool'- the inner side of the top of the main shell 12 with its upper flange lying flush with the top of the lining 13 so that the lwide bases 39 rest on and are secured to the angle iron. The lining 13 is overlapped by the bottom ends of the lower ring of wear plates 37.

,These plates are each provided with a series of bosses 40 recessed to receive nuts 41 applied to the inner threaded ends of the bolts 42, which bolts pass through the outer wall of each Wear plate 37 and have their heads 43 adapted to be received in the recess 44 provided in shoulders 45 cast integral with the outer jacket plates 36. The recesses are T-shaped, as viewed in plan, with the head adapted to receive the bolt head 43 and the stem adapted t'o receive the bolt shank. By this arrangement the plates 37 can be replaced by `unscrewingthe nuts 41 and new plates can be readily set intheir place. If the bolts have been damaged new bolts can be set in recesses 46 without taking out the outer jacket plates 36. 'Ihe shoulders '45 on the outer jacket serve to space the inner wear plates 37 therefrom and this space I ill with a suitable refractory lining s o that it is unnecessary to Water cool the upper jacket which `it is highly desirable to avoid under many operating conditions. Both the inner and outer metal linings at the top of the furnace stack have aligning openings for forming the opening 35 for the down comer. The dotted line 47 indicates the desirable stock level and from A this it will be apparent that the abrasivewear from the feed of stock will be largely conined to the upper belt or belts of the Wear plates 37, but these being highly resistant to wear will have almost indefinite life. The diameter of the inner jacket lining 37 conforms`with that of the refractory lining 13 and the internal diameter ofthe furnace gradually enlarges at the proper rate of increase froml the top of the furnace to the point of juncture with the bosh lining 8 and below that it contracts at` the described rate towards the hearth. The metallic top of the jacket will hold its diameter constant and the cooling blocks will hold the diameter of the furnace lining substantially constant so that no ledges are provided to interfere with the normal and gradual descent of the stock and the latter, as it expands, will 'follow down the gradually expanding diameter of the shaft and when it has reached its maximum expansion .and commences to contract,

due to melting, it will have reached the upper end of the bosh and will thus continue its of their expansion.

. uniform and gradual. movement through the bosh to the hearth. The wear plates 37 are mounted with sufficient clearance 'to take care /My nevs1 type of furnace is capable of withstanding high operating heats and is not inJ jured by the blowing out `of the furnace, or

changing it from oney to another product, as for instance from foundry iron to spie el, or

-ferro-manganese, or high silicon meta and' after long use an examination of the lining will show the original refractory'brick lining very largely replaced by burden material.

In the ractice of my invention, after lonO continue use, the refractory lining exposed to the highest temperatures is gradually melted away until the tips of some of the blocks become encased in the replacement lining formed of partially fused stock which agglomerates around the cold tips of the blocks ment of blocks which Would fail if water system became clog ed or, cut ofi".

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

1. In a metallurgical blast furnace, in combination, a hearth, a-bosh,and a stack having a main metallic shell extending partway to its top, a contractedmetallic shell rising above the main shell and supported thereon, and a top mounted on the contracted shell,the main shell havin a refractory linino and the contracted shell having a metallic .'Iining, said linings providing 'a gradually enlarging diameter for the furnace downwardly to the bosh, and neans incorporated in the refractory lining throughout the portion thereof subjected to stack, and closely associated cooling agencies rigidly connected to the shell and interspersed throughout the high temperature zone of the refractory lining and adapted to maintain substantially constant its thickness by replacement from burden material as said -lining wears or falls away, thereby maintaining a substantially unchanginginternal contour for the furnace linings.

3. In a blast furnace, astack comprising a main shell with suitable liningand superimposed above the main shell a contracted upper shell,l andmetal wear plates form-ing a lining for said upper shell.

4. A blast furnace according to claim 3, in

which the wear plates have means for mountl ing them for inward disengagement from the ternal notche upper shell, and a refracto lining between the wear plates and upper Ishell.

. 5. A blast furnace according to claim 3, in which the upper shell has a plurality of bosses on its inner surface which are notchedand wear plates have outwardly projecting ele-V ments for detachably interlocking them with said bosses, and a refractory lining interposed between the wear plates and their supporting shell.

6. A blast furnace according to claim 3, in which the upper shell is provided with inbosses, and wear plates have internal recessed bosses, and plate mountin bolts projecting through the wear plates an having heads 4adapted to engage in said notched bosses and nuts housed in said recessed bosses.

7 In a blast furnace, a stac-k comprising a main shell with suitable lining and super-` imposed above the main shell a contracted upper shell, metal Wear (plates forming a lining forx said upper shell, and means for mounting the metal wear plates for inward disengagement from the upper shell.

8. In a blast furnace, a stack having parts defining relatively high and low temperature zones, respectively, the part defining the low 4temperature zone being supported by the part defining the high temperature zone, means for maintaining a relatively thin agglomerate lining of substantially uniform thickness in thev high temperature zone of the stack, said means comprising closely spaced cooling elements eXtendin uniforml through the outer wall of the stac said cooling elements being maintained at such a temperature and being e so disposed as to chill and lagglomerate the descending stock immediate thereto, and a the stack, said means comprising closely" spaced cooling elements extendin uniformly through the outerwall of the stac said cooling elements being maintained at such a temperature and being so disposed as to chill and agglomerate refractory components in the descending stock immediate thereto, a metallic sectional and replaceable lining for the relatively low temperature zone of the stack above the high temperature Zone, and means for detachably holding the metallic lining sections in place. L

10. In a blast furnace, an 'upper relatively cool section having ametallic lining, a lower relatively high temperature'section having a metallic jacket and supporting the relatively cool section, and means for maintaining a relatively thin agglomerate lining forming substantially a proJection of the metallic lining, said means comprising closely spaced cooling elements extending uniformly through the metallic jacket approximately to the projected surface of the metalliclinlng, said cooling elements being maintained at such temperatures and beiiig so disposed as to chill and agglomerate the. descending stock immediate thereto. V

In testimony whereof I affix my signature.

JAMES P. DOVEL..

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