US2277447A - Shield for blast furnaces - Google Patents

Description

March 24,1942. 7 5 MOORE I SHIELD FOR BLAST FURNACES 2 Sheets-Sheet 1 Filed Nov. 22, 1940 [Hum e107": [48L 5 M0055,

in? flffar/ky March 24, 1942.

E. E. MOORE SHIELD FOR BLAST FURNACES Filed Nov. 22, 1940 2 Sheets-Sheet 2 Patented Mar. 24, 1942 UNITED STATES PATENT OFFICE SHIELD FOR BLAST FURNACES Earl E. Moore, Gary, Ind. I Application November 22, 1940, Serial No. 386,775

Claims.

I This invention relates generally to. blast furnaces and more particularly to the provision of an outer spaced shell or shield therefor as a protective covering and as a means of maintaining a uniform temperature for the underlying metal jacket of the blast furnace, in order to avoid excessive strains and stresses due to widely varying differences in the temperature of difierent portions of the jacket, particularly in instances wherein the furnace lining has become thin from abrasion or other causes, and where a hot spot has developed in the metal jacket or shell.

In the operation of blast furnaces, where the brick lining has been reduced in thickness, the heat transferred to the outer metal jacket at such point is greater than to other adjacent por tions where the normal thickness of the brick lining exists. Such uneven transfer of the heat results in widely varying temperatures of different portions of the jacket, which differences in temperatures, create severe stresses in the relatively thick steel plates in the jacket. The thickness of such plates will vary from three-fourths of an inch to an inch and a quarter. conditions, if there is a sudden lowering of the temperature to which the outer jacket is subjected, as, for example, by the blowing'of a heavy wind or sudden change in atmospheric temperature, stresses and strains of such an excessive and aggravated character have been known to be setup in the outer jacket as to cause cracking of the steel plates of the jacket, causing considerable damage to the furnace and necessitating the expense of replacement or repairs and otherwise jeopardizing the life of the furnace.

Under such segregation of the coarser particles of the charge or burden of the furnace, along one side. This results in a more open portion of the charge presenting a zone of least resistance to passage of the gases and air, with the result that a more violent reaction takes place at this point, and if continued for asufllcient period of time, may

nace being subjected to such excessive strains,

due to differences of temperature, as to causecracking or other damage.

A further object is to provide a means of maintaining or regulating a substantially uniform temperature or rate of change thereof throughout a greater portion of the metal acket arranged immediately adjacent the outer surface 'of the furnace lining, and to also provide a means whereby any selected portion of the furnace jacket may be subjected to a more intensified cooling action than other portions, of the'jacket under such conditions, for example, as the development of a hot spot. I

A further object is to provide a protective shield for a blast furnace, which shield is held in spaced relation to the usual outer steel jacket,

a construction being provided which is readily assembled and disassembled so that any.partic-" ular horizontal section of the underlying jacket I throughout the height of the blast furnace may be readily accessible without requiring dis-' mantling or removal of portions of. the outer shield above or, below the portions to which it is desired to have access. As a structural feature, it is a purpose to minimize the necessityfor use of rivets, welding, or other means of effecting permanent connections.

A further object is to provide for a blast furnace an enveloping substantially cylindrical air chamber surrounding the blast furnace, in which chamber heating or cooling of the steel jacket of the furnace may be effected by transmission of heat by eitherconvection, conduction or radiation, as desired, and to further provide means for rendering readily accessible any particular portion of the outer surface of the conventional steel jacket of .the blast furnace so that, if desired, temperature readings may be made at any such points as reflecting, in a comparative sense, the temperatures within the furnace at such zones; or as indicating the relative thickness of the lining at such zones, as compared with other sections. The provision of an accessible confined air space adjacent the jacket about the furnace enables temperature readings to be more readily and accurately made than under conditions where the jacket is subjected to direct exposure to the outer atmospheric conditions. An enveloping chamber for the furnace of the above character may have various applications and utilities by connecting the upper or lower portions thereof with various sources of air, gas, or liquid supply at either the point of entry or discharge of the furnace. Conditions are favorable in high tower-like chambers of this character for afiording larger areas for contact reactions to efiect physical or chemical changes in gaseous or liquid products.

Other objects and advantages may be apparent from the following description.

The invention will be better understood by referring to the following drawings showing one preferred form for purposes of illustration, but

not for limitation, as it is understood that various changes and modifications in detail of certain portions may be made without departing from the essential features of the invention.

In the drawings:

Figure 1 is an elevation view of the blast furnace, partly in section, and indicates in dotted line the manner in which the furnace lining may be impaired;

Figure 2 is a transverse section of the blast furnace taken on the line andlooking in the direction of the arrows IIII of Figure 1, and shows the annular air chamber enveloping the blast furnace together with. the shield spacing and supporting means, and the air conditioning and jacket cooling means in said chamber;

Figure 3 is a fragment in vertical section looking in the direction of the arrows and taken on the line IIIIII of Figure 2, showing particularly one plate of one frusto-conical section of the outer shield, together with the supports for the outer plate including a short length of an I-beam spacing member, and L-shaped channel ring members; there is also shown a water pipe for cooling;

7 Figure 4 is a fragment in vertical section look ing in the direction of the arrows and taken on the line IV'IV of Figure 3, and more clearly shows the-relative position of the spacing member-such as a short I-beam section-and the manner of securing the ends of sections of the encircling -L-channel on the flanges at one end of the I-beam;

Figure 5 is a fragment in vertical section looking in the direction of the arrows and taken on the line V-V of Figure 4, and more clearly shows the spring clip means for detachably mounting the plates upon the vertical flange of the encircling supporting rings of the ,L-channel bars; and

Figure 61s a fragment in vertical section look-v ing in the direction of the arrows and taken on the line VIVI of Figure 4 and shows more clearly the arrangement of the sag-rods which serve as a means of distributing and transmitting a portion of the weight of the plate load upon the channel rig members to the outer conventional jacket encasing the lining of the blast furnace.

In the illustrative form, a blast furnace is shown as including a conventional bush and hearth portion I, at the bottom portion thereof (a fragment of which is shown' by broken lines). Such portions are supported in the conventional manner on columns 4, which are shown also as supporting a portion of the conventional mantle of the furnace, and also a section of the water draining troughs WT for conducting the cooling water discharged from the various cooling plates of the furnace. The upper frusto-conical stack portion of the furnace is indicated generally by the reference character 3 and is shown as including the conventional refractory brick lining 5 and the outer steel jacket or shell 5 encasing the lining.

The usual reenforcing steel bands I are shown.

A portion of the refractory lining which may have been impaired, due to any one of a number of causes, is indicated at 8 which shows a portion of the furnace lining of reduced thickness, at which point a greater portion of the heat is conducted through the lining of reduced thickness to the outer steel shell, which may result in a hot spot at such point 9, if heated for a sufficient period of time, or if the thickness of the lining is further reduced.

In the event of the formation of hot spots in the steel jacket of the furnace it may be possible to continue operation of the furnace and prevent the intense heat in the jacket from burning through or destroying the jacket at the hot spot, by applying a stream of water at the hot spot in order to reduce the temperature of the metal jacket at that point. A temporary lining may be formed within the furnace adjacent the hot spot, by the fused ore that passes by such spot.

As shown in the drawings, the outer shell designated generally by reference character I0 extends from top to bottom throughout the height of the furnace and is spaced from the jacket so as to provide an enveloping annular space H between the jacket and the outer shell. The shell is shown as comprising a plurality of truncated cone sections, one such section being generally designated as l3 (see Figure 1). The sections are so disposed that overlying sections assume a slight telescoping relation, with the lower portion of one section overlapping slightly the upper portion of the section immediately below. This relation is clearly shown in Figure 1 and also in Figures 3 to 6.

Each frusto-conical section in turn includes separate plates l2, having their vertically disposed edges arranged in slightly overlapping relation so that any separate plate may be independently positioned and removed, in order to afford access to a corresponding portion of the jacket, without disturbing any substantial number of adjacent plates. As a means of supporting the plates [2, a series of ring members l5 are provided, each of varying diameter (for instance when used in connection with a frusto-conically shaped stack). Means for positioning said rings on the jacket serve also as a spacing means between the jacket and the outer shell.

The ring members designated generally as l5 circumscribe the furnace and are held in spaced relation from the jacket by a suitable means. As shown in the preferred form (see Figures 3 and 4), a relatively short section or piece of an I-beam designated generally as I4, is employed, having its web portion 14 disposed in a vertical plane. The flanges I4 at one end of the I-beam serve as a base or footing engagement with the outer face of the jacket and preferably are welded thereto although other suitable means of connection may be employed. Such base l4 transmits the downward and radial stress from the plate load on the spaced ring frame members [5 to the jacket 6.

The flanges M at the opposite or outer end of the web portion I4 of the I-beam serve as a ponvenient means of supporting the encircling rings designated generally as [5, by a suitable fastening means such as a bolt and nut connection I6. The bolt and nut connection servesas a convenient means for facilitating assembly and positioning of the ring members -.l5 relative the I-beam spacing member l4, particularly when the ends of the ring member l5, or sections thereof, are secured to the flange portions W on opposite sides of the web I4. This structure and arrangesment. is more clearly shown in Figure 4. The

. ring members I 5 are preferably formed in sections inorder to facilitate handling in assembly, and. also in fabrication thereof. The-desirability of this becomes apparent when it is considered that blast furnaces are of substantial size, some having a height from the base of the mantle to 'the top of the charging dome of '75 feet, and an outside diameter at the shell of 35 feet. In the preferred form shown, each ring member 15 is formed of four sections and the I-beam spacing members are disposed at points spaced 90 degrees apart about the circumference of the furnace, and at the point where the ends of the quadrant sections of the rings are connected together J through the medium of the outer flange 14 of the I- beam. In this manner, the I-beam section conveniently serves a double function of a spacing member and a connector. By virtue of the connection of the outer flange with the ends of thesections of the ring member, such flange portion of the I-beam becomes a part of the ring. It is, of course, understood that if desired, other suitable means of connection between the I-beam and the ring members or sections thereof may be employed, such, for example, as a weld connection. The connection with the ring members may also be made at points other than the ends of the sections of the ring. Where the -I-beam spacing member is employed in connection with a portionof. the blast furnace, which'is tapering on the outside, as, for example, when of frustoconical contour, when the ring members are connected to the outer web of the I-beam, the tapering contour of ,the jacket 6 of the furnace itself serves as a means for maintaining the I-beam and the loaded ring'members connected therewith in proper relative position. However, a

' 'welded connection between the inner flange l4 of theI-beam and the jacket 6 prevents any the ring member. As indicated in Figure 1, three of such detachable spring-like clip connectors II are provided for each plate, two such clips being provided. for connection with the upper ring member of a frusto-conical section, said clips being disposed adjacent the side edges of the plate, and oneclipbeing disposed near the lower portion of the plate and adapted to slidably engage "the upstanding flange l5 of the lower ring. member of the section. It is, of course, understood that a different number of clips for a plate, and various disposition and arrangement of the detachable clips, may be employed. Modified forms of clips may also be used for effecting the detachable plate connection.

For a blast furnace of the dimensions above referred to, plates having a length of approximately 7 feet and awidth of from .3 to 4 feet, have been found satisfactory as a convenient size to handle. An overlapping at-the side edges of the plate of approximately 4 inches and an overlapping of 3 inches at the top and bottom edges with plates ofadjacent frusto-conical'sections of the furnace has been found satisfactory.

Inlorder to prov'de an additional strengthen-- ing of'and support for the loaded quadrant sections of the ring members l5, intermediate their connections at the ends with the I-beam N, there may be provided U-channels ill at suitably spaced intervals (see Figure 2), which are interposed between the upstanding flange l5 of the ring member, and the jacket 6. Additional means may s also be provided to restrain any tendency of the tendency toward relative movement of the parts.

- As shown in section in Figures 3, 5 and 6, the ring members l5 are formed preferably of L- shaped channel members having one of the flanges IS in a substantially upright position, and the other flange I5 substantially vertical and extending within the'space ll formed between the outer steel shell l0 and the innerjacket 6; It is with such upstanding flange of the,

ring member, that the connection of the outer flange of the I-beam is made. Such upstand- V ing flange l5 of the L-channelserves also as a convenient means for establishing a detachable connection with a series, of outer plates [2 which form the main outer steel 'shell designated generally as ID.

A preferred means for efi'ecting'a detachable mounting for the plates I2 upon the ring member I5 is more clearly "shown in Figure 5. Preferably, the plates I! are supported on ring sections which are vertically spaced frbm eachother and are disposed at points adjacent the upper and lower edges of the plate [2, but at distances within or between overlapping portions of plates of ad jacent frusto-conical sections, above and below.-

As a means of affording a detachable mounting of the plate l5 upon the vertical flange portion I5 of the ring member there is provided a clip member designated generally as IT, having an upper portion thereof I'I secured to theinn'er face of the plate 12 by rivets It or other suitable means. The lower portion ll of the clip is bent outwardly to form an offset spaced portion adapted tomeceive the upstanding-flange I5 ofof the blast furnace jacket by a fluid cooling quadr'antring sections to sag at points intermediate its end connections with the I-beam. For this purpose, there may be employed sag-rods 23 (see Figures 4 and 6), the upper end of which may be detachably secured to a boss or flange secured in any suitable manner, as, for example, by welding to the jacket 6; and the lower end of the sag-rod 23may be detachably connected to a portion 'of the upper ring member of a frusto-conical section, which connection with the ring may be made many suitable manner. As shown,

. short lugs or arms, are spaced apart a distance sumcient to receive the sag-rod therebetween, such lugs being securely fixed. in any suitable manner, as by welding to thering section. If desired, the lower end of the sag-rod may be detachably secured to the ring member [5 by providing suitable apertures in the horizontally.

disposed flange l5 of such ring member to permit a threaded end of the sag-rod to pass there- 'through to receive a washer and nut. Preferably,.the boss or flange connector for the upper end of ,t he sag-rod is disposed on the jacket at a point adjacent, and preferably above,'the upper portion of the frusto-conical section for which it serves as a support. Such'a, disposition facilitates the assembly of the parts by permitting access to parts, and particularly the. positioning and tightening of the sag-rods.

As a means of controlling or regulating the temperature of the air within the space H between the jacket 6 and the outer shell Ill, and as a means of cooling the entire'outer surface velop in the furnace jacket, the cooling medium may be employed to condition the air within the space to induce circulation of air within the space. Due to the height of the confined air column between openings at the top and bottom, and due to differences in temperature that may exist, conditions are such that a substantial flow or draft of air may be induced. In this respect the outer shell enables a draft or circulation somewhat comparable to a flue-like effect to be obtained.

Under certain conditions, an enveloping annular chamber of the character herein disclosed may be adapted to various uses and purposes for treating and conditioning gases or liquids conducted therethrough, by connecting the upper, intermediate, or lower portions thereof with various sources of air, gas, or liquid supply at either the point of entry to or discharge from the blast furnace or other chamber in a conventional manner, well known in the art. In addition to the favorable conditions existing in a high shell-like annular chamber, serving as a means for effecting large contact areas throughout substantial distances for effecting transfer or interchange of thermal heat energies, such conditions are also favorable for utilization in recovery processes of by-products.

While one preferred form of invention has been shown for purposes of illustration, modifications in detail of various parts may be made without departing from the spirit and scope of this invention, as defined in the appended claims.

I claim:

1. In a blast furnace having a frusto-conical stack portion and a metal jacket therefor encasing the refractory wall and lining thereof, an outer cooling shell spaced from said jacket, and spacing means for supporting said shell in spaced relation to said jacket whereby an air space is formed between said jacket and shell, said shell spacing means including a series of spaced supporting rings arranged to form a frusto-conical frame, each ring being independently supported on said jacket, said shell being of frusto-conioal form and including a plurality of frusto-conical sections having their upper and lower edges in overlapping relation with adjacent sections, each section including a plurality of plates arranged in overlapping relation, each plate being separately independently, detachably mounted on said frame, whereby any one of the plates of the shell may be removed independently.

2. In a blast furnace having a frusto-conical stack portion and a metal jacket therefor encasing the refractory wall and lining thereof, an outer cooling shell spaced from said jacket, and spacing means for supporting said shell in spaced relation to said jacket whereby an air space is formed between said jacket and shell, said shell spacing means including a series of spaced supporting rings arranged to form a frusto-conical frame, each ring including an L-channel and being independently supported on said jacket, said shell being of frusto-conical form and including a plurality of frusto-conical sections of different sizes and having their upper and lower edges in overlapping relation, each section including a plurality of plates, each plate being separately independently, detachably mounted upon the L- channel of said ring,- whereby any one of the plates of the shell may be removed independently to permit access to an underlying portion of the jacket without disturbing any substantial number of adjacent plates.

3. In a blast furnace having a frusto-conical stack portion and a metal jacket therefor encasing the refractory wall and lining thereof, an outer cooling shell spaced from said jacket, whereby an air space is formed between said jacket and shell, said outer shell including a plurality of frusto-conical sections arranged in overlapping, telescoping relation, each section including a separable and independent unit, capable of being assembled or disassembled independently of the other sections, each section including a plurality of spaced rings of different diameters independently carried by the jacket, supporting and spacing means for holding each of said rings in spaced relation to the jacket adjacent the upper and lower edge of each section, said supporting and spacing means including a relatively short I-beam section having the web thereof disposed in vertical plane, the flanges at one end of said I-beam section resting on the jacket and the flanges at the other end of said I-beam section engaging the rings, each ring including a plurality of arcuate sections of L- shaped channel presenting one of its flanges in a substantially vertical plane and being so disposed as to lie adjacent to and be secured to the flange at one end of said spacing I-beam section, and securing means for connecting the outer flanged end of said spacing member and one of the flanges of said ring member, each frustoconical section also including a plurality of plates being connected to said rings by a hooked clip connection adapted to engage the vertical flange of said ring, whereby any horizontal section of the shell corresponding with any one of the frusto-conical circular sections or any plate of said section may be removed independently without requiring disassembly of other sections or other plates, and sag-rod connectors, one end of said sag-rod being connected to the jacket and the other end being connected to the spaced ring member on which the plates are supported.

4. In a blast furnace having a stack portion and a metal jacket therefor encasing the refractory wall and lining thereof, an outer shell spaced from said jacket, whereby an air space is formed between said jacket and shell, said outer shell including a plurality of sections, each section including a plurality of spaced rings carried by the jacket, supporting and spacing means for holding said rings in spaced relation to the jacket, said supporting and spacing means including a relatively short I-beam section, each ring including a section of a flanged channel member presenting one of its flanges in a substantially vertical plane, and securing means for connecting the outer flanged end of said spacing member and one of the flanges of said ring member, each section also including a plurality of plates, and, connecting means for detachably mounting and securing said plates in position upon said ring section.

5. In a blast furnace having a frusto-conical stack portion and a metal jacket therefor encasing the refractory wall and lining thereof, an

outer cooling shell spaced from said jacket, for connecting the outer flanged end of said spacwhereby an air space is formed between said jacket and shell, said outer shell including a plurality of frusto-conical sections arranged with their upperand lower edges in overlapping telescoping relation, each section including a separable and independent unit, a plurality of spaced rings of different diameters, supporting and spacing means for holding said rings in spaced relation to the jacket, said supporting and spacing means including a relatively short I-beam section, each ring including a section of a flanged channel member presenting one of its flanges in ing member and one of the flanges of said ring member, each frusto-conical section also including a plurality of plates adapted to engage the vertical flange of said ring whereby any horizon- I tal section of the shell corresponding with any a substantially vertical plane, and securing means one of the frusto-conical circular sections may be removed independently in whole or in part without requiring disassembly of other sections, and sag-rod connectors interposed between the jacket and the ring members on which the plates are supported. 7

EARL E. MOORE.

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