US1703519A - Method for the protection of blast-furnace jackets - Google Patents

Description

Feb. 26, 1929.

J. P. DOVEL METHOD FOR THE PROTECTION OF BLAST FURNACE JACKETS Original Filed Sept. 17, 1923 IIIIIIII Inventor Patented Feb. 26, 1929 I :rA nsr. DOVEL, or BIRMINGHAM, ALABAMA.

METHOD IOR THE PROTECTIGN OF BLAST-FURNACE JACKETS.

Original application filed September 17, 1923, SerialNo. 63,283. Divided and this application filed March 16, 1928." Serial No. 262,268.

My invention relates to blast furnaces and has for its object the provision of a process for producing an agglomerate lining for such furnaces.

A further object of my invention is to provide a process for producing and maintaining a lining for a blast furnace com rised of agglomerated refractory particles rom the stock and self replaceable in operation of the furnace. I

The invention herein described is a division of my application for Letters Patent, Serial No. 663,283, filed September 17, 1923.

Heretofore, in this art, it has been the practice to incor orate in the refractory brick lining of the urnace above the bosh a number of cast iron coolers connected up with a source of circulating .water, and it was the purpose and function of these coolers to protect the surrounding brick work in the lining from temperatures that would melt the same, .and thus the theory was that these coolers would greatly increase. the life of the lining. In practice, however, experience has shown that when the lining has worn away so as to expose these coolers, either from abrasion, heat, or chemical action, the coolers would invariably burn out or fall out by reason of inadequate support and thereupon the furnaceman was subjected to ex ense and trouble of relining his furnace. am aware, no practical provision has heretofore been made for the removal and replacement of cooling blocks in the brick lining above the mantel, thereby making it possible to repair the furnace.

. In the operation of certain blast furnaces under my charge I experienced an abnormally rapid destruction of the lining in a zone extending about twenty feet above the bosh. Throughout a large portion of this zone, which was water cooled, the brick lining was entirely burned away and the shell would have been exposed to the raw stock and the intense heat except for a thin lining of an agglomerate material which formed on the shell and supported the brick lining above .it. After an examination of this condition I 0011-" ceived the idea of building up within the furnace an agglomerate lining composed entirely of slag and stock materials by-the intro+ 'duction through'the shell of cooling elements 1 preferably in the form of standard bronze bosh blocks, and by arranging these in such' .relatmn tha th p tia lymolten metal and ofar as I a metallurgical blast furnace havm a 1, and above this the usual metal acket or fine particles of the stock would agglomerate and build up on and about same until a complete protection or lining having approximately the thickness of the original lining wouldcover the acket throughout the zone under treatment, or the whole jacket, were it desired to provide the original lining by this v method.

My invention therefore comprises the method of utilizingsuch blocks so as to build up by an agglomeration of stock a protecting lining in the furnace jacket. The lining so built up within the furnace in actual practice. has proved more effectivev than the brick lining and far less subject to deterioration.

The method of practicing my invention and the preferred embodiment of the means to that end will be best understood by refer.- ence to the accompanying drawings, which form. a part of these specifications, and in which Fig. 1 is a partial elevation and partial section through a furnaceequipped with my invention.

Fig. 2 is an enlarged side elevation of a cooling block with its individual mounting frame mounted in the jacket, and

Fig. 3 is an end elevation of Fig. 2, showing the block mounted iii an individual frame.

Similar reference numerals refer to similar parts. throughout the drawings.

In the practice of my invention I propose to protect the jacket of any type of blast furnace above its bosh, by means which will cause created by the utilization of my method and process, as well as that an existing lining may,

be repaired and replaced in part whenever it has failed. I

To illustrate the practice of my invention I have shown in the accompanying drawgggs shell 2, which "in the drawings is shown as having beenpreviously lined with refractory brick 3. Throughout the zone. of maximum abrasion and heat, extending generally about 20 feet above the boshgI-jhave 'shown the l nwere provided and for each block an individual mounting frame 6 was used, this frame having its body portion curved to conform to the curvature of the jacket, and having also a slightly tapered inturnedflange 7 surrounding the opening in the frame and adapted to receive the block with a snug, gas tight fit when driven home therein. The jacket has an opening 8 cut therein to receive the flange 7. The frame will overlie the jacket about the opening 8 therein sufliciently to receive attaching means to connect it to the jacket. Preferably bolts 9 are' used, these being inserted after the frame was mounted in the jacket opening by passing the threaded ends of 'the bolts outwardly through the jacket and frame and applying nuts to detachably mount the frame with a gas tight joint on the jacket. The cooling blocks are then driven home in their respective frames and when in place are connected up in series by water supply pipes 10, each at one end connected to the inlet nipple 11.at one side of a block and at the other end connected to the outletnipple 12 of an adjacent block. The

' blocks as thus mounted in the furnace can be connected up in any suitable manner with each other and with a source of cooling water.

The blocks are to be introduced in the furnace I in such relative positions as will produce the results in view. If used to treat a small hot spot, they should be located in such relation thereto that the agglomeration of stock, as indicated at 13 thereon, would gradually fill out the worn or missing portion of the linin at the hot spot. If an entire zone is to be ined or relined the blocks should be arranged at different levels and staggered, the spacings between the blocks being such that they would cause'an agglomeration to extend sufficiently to overlap from block to block. In practice I found this to occur satisfactorily where the blocks on a given level were spaced on three foot centers and the lines were spaced about five feet. When so arranged it was found thatwithin a very short time there had agglomerated or built u on and around the blocks a lining of semi-re actory material composed of particles of ore, ashes, silica, graphite, coke and alumina. The lining thus formed was very hard, and as cooled by the embedded blocks, was sufficiently refractory to withstand the furnace temperatures. I found by removing a bosh block under as over the blocks, it evidently being the case that a gradual accumulation of the semi-molten stock would'build up throughout the zone cooled by the blocks until all of the jacket was covered and all of the blocks were entirely embedded in such agglomerate linin In a furnace which for 20 feet above its bosh was entirely devoid of brick lining I succeeded, by the placing of cooling blocks in the manner described, in building up an ag- 'glomerated replacement lining in a very short time, and from careful inspections and tests of this lining there is no evidence of any deterioration in it at all, apparently there being a gradual replacement of the lining as it is worn by abrasion. This would seem to result from the fact that throughout the entire zone in which the cooling effect of the block is appreciable there will be no diminution of this agglomerated lining. In the event any of the blocks should fail for any reason, it is a very simple and inexpensive matter to unbolt its respective mounting frame, disconnect its pipes 10 and take out the frame and block: for inspection, if necessary shutting off the blast temporarily. The block can thus be readily inspected, a new'block substituted, and its mounting frame remounted in the jacket. It will be noted that the jacket directly supports the frame and block because the flange 6 will rest on the bottom of the jacket opening 8.

It is one of the most important features of my invention that the frames will permit the blocks to be very readily mounted with a gas tight joint in the furnace while making it simple to remove and replace them. It is to cohere to and build up about them until a lining is formed.

2. The hereindescribed process for lining a furnace, which consists in causing an ag glomerate mass of stock comprising molten and semi-molten particles to take hold upon water cooled parts and build itself up into a lining for the furnace. l

3. The hereindescribed process for replac-- ing the lining of a furnace jacket, which consists in mounting one or more water cooled blocks to project into the space formerly occuimportant that these cooling blocks be mount-.

throw the entire weight of lining pied by the lining to be replaced and to. collect about their overhnng inner ends a\composite agglomerate lining of stock materials which ultimately embed the block and protect it.

4. The hereindescribed process for creating a lining within the jackets of blast furnaces and the like, which consists in mounting water cooled blocks to project substantially inwardly beyond the furnace walls so that an agglomeration of stock material. will accumulate on and about said blocks, and spacing said blocks on centers to produce cooled zones which overlap throughout the space to be lined.

5. The process of producing a lining for the metal jacketed wall of a blast furnace stack which comprises providing cooling elestack which comprises providing cooling elements within the metal jacket adjacent the inner periphery thereof to contact with and agglomerate heated particles of furnace stock immediate thereto.

7. The process of producing an agglomerate lining within the metal jacketed wall of a blast furnace stac'k which comprises chilling the heated descending stock in the furnace adjacent said metal jacket.

8. The process of producing a lining Within the metal jacketed wall of a blast furnace stack which comprises chilling the heated descending stock in the furnace at a plurality of points adjacent said metal jacket to agglomerate particles of the stock in areas immediate said points, said areas overlapping to produce a solid lining.

In testimony whereof I aflix my signature.

' JAMES P. DOVEL.

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