US3351460A - Method for prolonging the life of refractory linings in furnaces of the kaldo, linz-donowitz, de may or basic or acid converter types - Google Patents

Method for prolonging the life of refractory linings in furnaces of the kaldo, linz-donowitz, de may or basic or acid converter types Download PDF

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US3351460A
US3351460A US424071A US42407165A US3351460A US 3351460 A US3351460 A US 3351460A US 424071 A US424071 A US 424071A US 42407165 A US42407165 A US 42407165A US 3351460 A US3351460 A US 3351460A
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furnace
lining
furnaces
refractory
steel
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US424071A
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Raymond J Demaison
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Quigley Co Inc
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Quigley Co Inc
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Priority to US424071A priority Critical patent/US3351460A/en
Priority to GB55062/65A priority patent/GB1134699A/en
Priority to FR44161A priority patent/FR1465796A/fr
Priority to GB26831/68A priority patent/GB1134700A/en
Priority to ES0321460A priority patent/ES321460A1/es
Priority to DE1508235A priority patent/DE1508235C3/de
Priority to SE09511/68A priority patent/SE365547B/xx
Priority to JP66622A priority patent/JPS52883B1/ja
Priority to BE674856D priority patent/BE674856A/xx
Priority to ES0327995A priority patent/ES327995A1/es
Priority to US663864A priority patent/US3518330A/en
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/42—Constructional features of converters
    • C21C5/44—Refractory linings
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/42—Constructional features of converters
    • C21C5/44—Refractory linings
    • C21C5/441—Equipment used for making or repairing linings
    • C21C5/443—Hot fettling; Flame gunning

Definitions

  • This invention is directed to a method of maintaining against progressive deterioration the flame exposed refractory surfaces of high temperature furnaces of the basic oxygen type, such as the Kaldo, Linz-Donowitz, De May, and basic or acid converter type, while the furnace is at or near its operating temperature.
  • the basic oxygen type such as the Kaldo, Linz-Donowitz, De May, and basic or acid converter type
  • the Linz-Donowitz and the basic oxygen converters normally oxidize most of the CO to CO outside the furnace with a resulting loss of available exothermic heat that could be utilized to melt higher percentages of scrap. Burning carbon to CO produces at least three times the heat of burning carbon to CD only.
  • the basic oxygen converters have in some instances realized this potential heat source as evidenced by the practice of positioning the furnace more towards the horizontal during start ups of cold furnaces or whenever a cold heat was apparent.
  • One of the first methods employed on a production scale to take advantage of burning most of the CO to CO inside the furnace, along with the use of pure oxygen lancing, is the rotating converter developed by Professor Bo Kalling and his associates and placed in full scale operation in May 1956 at Domnarvet, Sweden.
  • a rotating concentric cylindrical furnace is used and is inclined at 17 (degrees) from the horizontal so the melt will cover at least half of the back wall, and it is rotated at speeds up to 30 r.p.m.
  • the angle of inclination increases the productive capacity of the furnace and exposes more of the lining to the cooling effect of the mass of metal during rotation.
  • the high speed rotation provides a greater degree of slag to metal contact than does stationary converters and a slag is formed earlier herein than in other processes to result in the rapid elimination of phosphorus and at the same time result in a low loss of iron to the slag.
  • the rotor process of De May is similar in operation to the Kaldo process and the reactions achieved therein and the results obtained therefrom are therefore similar.
  • the basic converters are of two types, one top blown and the other bottom blown.
  • the furnaces are tilted and loaded with hot metal and/or scrap as desired.
  • the furnace is then moved to a-vertical position and the oxygen and/or air and steam is blown in either from the top by means of a lance or upwardly through the molten metal contained therein by means of holes contained in the bottom of the furnace.
  • the furnace is again tilted and the heat poured by means of a tap hole provided in the converging neck of said furnace. In some instances, water is sprayed onto the slag to congeal it and prevent it from running off through the tap hole.
  • the instant invention may be used on electric furnace linings as well as the linings of other furnaces to allow a greater number of heats to be produced during any one campaign.
  • the primary object of the invention is to insure a longer life to the refractory lining than could ordinarily be expected under the extreme operating conditions encountered, the net result being to bring down the lining cost per ton of steel produced and prolong campaigns.
  • Another object of the invention is to place on the flame exposed surfaces of the refractory lining, while it is at or near operating temperature, a protective coating which will prevent the deterioration of the parent lining and which will also be of such stability as to resist the erosion due to the movement of the hot metal and slag across the face thereof and, in addition, resist the abrasion from the additions of scrap metal to the furnace.
  • Still another object of the invention is to place on the flame exposed surfaces of the refractory lining coatings which will be compatible with the lining and with each other and still be of a greater refractoriness and resistance to higher temperatures than the linings themselves.
  • Yet another object of the invention is to provide suitable equipment, such as spray pipes with suitable spray nozzles and suitable supports arranged to be thrust into the furnace, to spray the material onto the flame exposed faces of the refractory linings in layers or coats and thus furnish the means for protecting said linings.
  • suitable equipment such as spray pipes with suitable spray nozzles and suitable supports arranged to be thrust into the furnace, to spray the material onto the flame exposed faces of the refractory linings in layers or coats and thus furnish the means for protecting said linings.
  • the spray pipes and supports may be water cooled to insure their continuity of operation.
  • a still further object of the invention is to operate a series of furnaces of any type whether Kaldo, Linz-Donowitz, electric or basic or acid converters on a preset program of production and rehabilitation in order to insure the continued operation of said furnaces over a much longer period of time than has heretofore been possible so as thus to increase the steel production for any given campaign.
  • the primary concept of the invention is to insure the production of greater tonnages of metal from any single furnace during any one campaign regardless of the type of unit or the linings employed therein.
  • the linings are varied in thickness depending upon the Wear pattern encountered, such as the charging side which has a higher abrasion resistant lining. In extreme cases, the normal linings have had a life of 250 to 300 heats during any one campaign, but this is extraordinary as the normal average life is around 200 to 225 heats.
  • Control of basicity and amount of slag by controlling the amount of lime to thus control the amount of silica in the metal and, in addition, controlling the amount of slag. Resulting in the iron content of the slag being kept as low as possible.
  • the same results may be achieved by changing the lance position while maintaining a constant oxygen input.
  • the other variable used in controlling furnace operation is the speed of rotation of the vessel. A high rate of rotation exposes more of the metal surface to the direct action of the oxygen while the slag is being swept along the walls of the furnace. In this operation, two separate reactions take place simultaneously to, first, cause the slag to lose some FeO through the reduction of the metal-slag contact and, second, the oxygen acts in part directly on the bath to result in greater decarbonization than dephosphorization.
  • a low rate of rotation causes the slag to absorb oxygen and thus oxidizes more iron from the bath to thus eliminate phosphorous at the metal-slag surface.
  • a slow rate of rotation favors dephosphorization while a high rate of rotation favors decarbonization.
  • step (a) it is not necessary that the furnace be operated four heats per day for thirteen consecutive days nor is it necessary that the spraying operations during this initial period be carried out during each day of the furnace operation.
  • the basic idea of this step (a) is to thermally condition the new brick lining and to build up thereon a series of successive protective coatings so as to substantially increase the thickness of the lining for operations during step (b) and step (c).
  • a new lining might be seriously damaged if the furnace were operated under normal conditions for the full normal or maximum number of heats per day, bearing in mind that the material of the lining has not achieved complete thermal equilibrium or stability, but even after it does achieve such a condition, it would still be subject to abrasion, erosion and spalling during normal operations and hence would lose its original thickness in the absence of the protective coatings.
  • These coatings are not applied continuously throughout the initial period to increase the thickness of the lining to the necessary extent, but they are applied in time intervals of sufiicient duration to permit the first coating to dry, set and fuse to the parent lining and each successive coating to dry, set and fuse to the preceding coating until the desired thickness of the lining has been achieved.
  • each successive coating is controlled according to the conditions under which the furnace is operated and the number of successive coatings is likewise controlled according to the con ditions under which the furnace is subsequently operated.
  • the successive protective coatings are applied at selected intervals during an initial period of operation of the furnace under norinal conditions. This is because the heat conditions existing Within the furnace during normal operation are differ ent from those that would exist if the lining of the fur nace were merely maintained at or near operating temperature throughout any given interval.
  • the lining is not only subject to the abrasion which comes from loading the furnace with scrap material, but also subject to erosion and spalling which come from the pouring of the molten metal upon the scrap material as Well as the agitation of the molten metal due to the blowing of oxygen into the molten metal.
  • the lining at one time is subjected to the maximum heat developed in normal operation and at another time to a lower degree of heat due to the temporary chilling of the molten metal under the conditions stated. It will not take too long to firmly condition the original lining and thereafter the applications of the protective coatings will enable it to withstand the severe conditions encountered because of increased thickness of the lining at the end of the initial period.
  • Another desideratum are the time intervals followed in applying the successive coatings to cause them to dry, set and fuse as above stated to enable them to react with the furnace gases, coating by coating, until the total number of coatings has been applied.
  • the total thickness of the coatings may reach as high as 6 inches and it can be appreciated that such a thick coating will not only increase the refractoriness of the lining as a whole but actually protect the parent brick lining against deterioration or spelling in subsequent operations due to the lower temperature gradients in the lining. And it goes without saying that the protection afforded the parent lining extends also to the shell of the furnace. In short, according to the present invention, this initial period, desirably 4 heats per day for 13 consecutive days, will actually control the total obtainable life of the lining.
  • the protective furnace lining will be able to withstand abrasion, slag and hot metal erosion and spalling which take place without the necessity of additional spraying.
  • the number of days of furnace operation during this intermediate period could of course be varied according to the increase in thickness of the lining during the first period.
  • the number of heats per day and the number of consecutive days comprising this final period may likewise be varied according to the increase in thickness of the lining during the first period and the reduction in such thickness taking place during step (b).
  • the spraying operations during this final period may therefore vary likewise but, in any event, there should be applied to the furnace lining during this final period an additional series of successive protective coatings of refractory material which will maintain the lining at willcient thickness to permit the furnace to be continued in operation throughout said final period.
  • the time intervals of coating applications, as in step (a), should be of sulficient duration to permit the first coating applied to the lining after step (b) to dry, set and fuse to the worn lining and each successive coating to dry, set and fuse to the preceding coating until the desired thickness of the lining has been achieved.
  • the aim in this final period is to maintain a uniform maximum thickness of the furnace lining at the wear pattern area, so that the spraying operation should preferably be performed during each days operation of the furnace.
  • the plan may be arranged to either run the furnaces for a few heats each day and replace the abraded, eroded and spalled material daily in small increments or the furnaces may be run for a greater number of heats per day and replace the abraded, eroded and spalled material in larger increments daily to result in days with no replacement to thus allow the operation of the furnace to be scheduled as desired taking into account the daily number of heats and tonnage output, the Wear pattern resulting from the heats put on the furnace daily, the rate of daily replacement of refractory material on the lining including the building up of the wear pattern areas as Well as overall build up, and the total number of heats desired on the furnace lining per campaign.
  • step (b) start with a new refractory lining in one furnace and proceed with a schedule worked out for the number of furnaces being activated and based upon the number of heats per day necessary to produce the desired daily tonnage.
  • the schedule is to be so arranged as desirably to always run a furnace in step (b), which means that one furnace will supply the maximum daily tonnage while another one is relined, and the other steps so arranged that the maximum daily tonnage will be jointly produced with the newly relined furnace supplying the smaller part of the tonnage.
  • the schedule is self-explanatory and is based on the fact that one furnace must always be in operation and wherever possible a safety factor should be worked in to insure constant production.
  • the normal object of the spraying programs as depicted under Notes 1 and 2 is to keep the linings in repair and of sufiicient thickness to preclude their failing until more than 500 heats have been accomplished. It has been ascertained that, in normal operation of the furnaces, about A" of the lining or sprayable material placed thereon is removed every 7 or 8 heats. The above scedule has been worked out and is now being used at several of the larger steel plants with very good success.
  • the refractory material used to mix with water to form the sprayable slurries will in the main depend on the type of lining used in the furnace and the mode of operation thereof. In the main, they will be chrome magnesite, magnesite-chrome compounds and straight magnesite. In all instances, the refractory compositions will contain suitable binders, suspension agents, and dispersion agents to insure the retention of the refractory material upon the surface of the hot refractory lining.
  • the spraying is started with the linings at or near operating temperatures and the refractory material is applied in layers or coatings; and when in any furnace, after applying several layers, the lining begins to lose its redness, a gas torch is used to bring back the lining to its normal operating temperature.
  • the loss of redness simply means that some heat has been used to dry out the layers of refractory material while some is lost in radiation, but the loss is not sufficient to cause a violent drop in the temperature of the center of the lining which could cause spalling.
  • the same is true in reverse, in'that in the reheating of the lining the heat of the center is still sufficient to allow the refractory material on the face to be brought up to operating temperature without causing spalling.
  • the lining may be kept at or near a given uniform thickness to allow over 500 heats .or more to be obtained.
  • the schedule divulged above is predicated on a particular operation of two furnaces in the field and the number of days in each step may be varied to suit the particular maintenance conditions and production schedules in each individual case. In this way it is possible to arrange the schedules so that they overlap and will allow one furnace to be relined while the other is carrying on somewhere near the beginning or center of a campaign to thus insure the minimum production needed from the shop.
  • the basic schedule may be used to work out a continuous production schedule using three furnaces to thus keep two of the furnaces continuously on stream with one furnace down for relining.
  • the normal down or relining period is approximately from 5 to 7 days in this particular instance and unless some defect is found in the shell of the furnace this time can be adhered to and the schedules built around it.
  • an additional day or two may be incorporated in the schedule and it will be noticed that there are 8 days shown in step (b) above, which means that there are 5 to 7 days for the relining of the furnace with 1 to 3 days as a safety period.
  • FIG. 1 is a cross sectional view of a basic oxygen furnace of the Linz-Donowitz type in a position tilted to the left for charging with steel scrap;
  • FIG. 2 is a cross sectional view of the furnace shown in FIG. 1 in the same tilted position but showing the addition of the hot molten iron;
  • FIG. 3 is a cross sectional view of the furnace shown in FIG. 1 but in a vertical position for the adding of slag forming materials, such as powdered limestone, etc.;
  • FIG. 4 is a cross sectional view of the furnace shown in FIG. 3 in a vertical position for blowing with oxygen and showing the water-cooled hood and oxygen lance;
  • FIG. 5 is a cross sectional view of the furnace shown in FIG. 4 but in a position tilted to the right for pouring the molten steel into a ladle;
  • FIG. 6 is a cross sectional view of the furnace in a horizontal position and tilted to the right for effecting repairs to the lining and showing in addition a cross sectional view of the floor and spraying apparatus in reference to the furnace;
  • FIG. 7 is a cross sectional view of a basic oxygen furnace of the Kaldo type and clearly shows the various positions assumed by the furnace during the operation cycle;
  • FIG. 8 is a cross sectional view of a basic oxygen furnace and shows the lining and the trunnions upon which the furnace is tilted during operation.
  • the furnace 1% with its lining 11 is tilted at a suitable angle for loading the steel scrap l2 thereinto from the body 13 mounted on the car 14. It will be noticed that the lining 11 of the furnace will be seriously abraded on the loading side as indicated at the area 15, thus giving rise to the first area to be repaired in order to keep the furnace in operation for longer periods of time. In some instances abrasion resistant bricks are installed in this area to keep this abrasion to a minimum amount.
  • FIG. 2 shows the hot molten iron 16 being poured over the scrap 12 from the ladle 17. There is little or no abrasion or erosion from the addition of the hot metal as it is poured over the scrap.
  • FIG. 3 shows the addition of the slag forming materials, such as powdered limestone 18, from the overhead chute 19.
  • the slag forming materials such as powdered limestone 18, from the overhead chute 19.
  • FIG. 4 shows the furnace fitted with the water-cooled hood 20 which is equipped with a duct for leading the hot gases into a suitable precipitator for removing the solid particles contained therein.
  • the hood 20 is fitted with the oxygen lance 22 so arranged as to blow the oxygen downwardly onto the molten metal and scrap.
  • the shell 21 of said lance is arranged for the circulation of cold water therethrough to thus protect said lance against deterioration from the high heat developed in the furnace. In this operation, due to the high heats encountered and the boiling action of the hot metal and slag therein, there is a definite wear pattern established.
  • the lining 11 of the furnace 10 is eroded at four definite areas as indicated at 25, 26, 27 and 28, and, strangely enough, the wear pattern at 25 and 27 is not always in circumferential form but occurs at 2, 4, 8 and 10 oclock positions on a section taken through the furnace with the smaller included angles being on the center line of the tilting mechanisms.
  • the wear patterns at 25 and 27 do not occur in a vertical line but are inwardly inclined and are caused by the hot metal and slag when the furnace is in the tilted position.
  • the wear pattern at 26 and 23 more or less is a continuous circumferential wear pattern as long as furnace operation variables are held constant and is caused by the erosion and spalling under the high temperatures encountered during the blowing period.
  • FIG. 5 shows the molten metal 30 being poured into the ladle 32 resting on the car 33.
  • the furnace is tilted so that the slag line 34 remains above the tap hole opening 35 to thus prevent the pouring of any of the slag out of the furnace with the steel.
  • the complete pouring and emptying of the furnace is accomplished by simply tilt ing the furnace a little more until all the metal has run out.
  • cold water is sprayed on the slag to congeal it before pouring to insure that no slag is poured.
  • there is little or no erosion taking place in the furnace proper but there is considerable erosion of the tap hole which necessitates its repair quite often in order to insure proper pouring of the heat.
  • FIG. 6 shows the furnace ltl in a horizontal position tilted to the right for effecting repairs to the lining l1 and also shows a cross sectional view of the floor 36 in reference to the furnace.
  • the boom 37 with the supply pipe 38 mounted on the top thereof and with the spray nozzle 39 aifixed to the pipe.
  • the boom is pivoted at 4ft, where it extends through the shield 41, to allow it to be tilted and thus spray the entire interior refractory surface of the furnace lining.
  • the shield 41 contains the window 42 of heat resistant glass to allow the operator to direct the spray onto the worn, eroded, abraded and spalled areas.
  • the shield is also formed of a steel plate of suitable thickness and lined with an insulation material either in brick or bat form, to keep the heat away from the operator.
  • Said shield is suitably mounted on the A-frame 43 to allow the whole unit to be moved forward or backwards as desired to thus position the boom with its spray nozzle.
  • the rear end of the boom 37 is weighted at 44 to counterbalance its forward inwardly extending end; and, in addition, the chain hoist 45 is connected by cable 46 to the extension 47 on the rear end of said boom to allow for vertical movement once the boom is in the furnace.
  • the A-frame 43 is fabricated of aluminum or steel and, being light and equipped with suitable wheels, can be readily moved on the floor 36 to position the boom within the furnace as desired.
  • the boom may be water-cooled in order to allow it to be used for longer periods of time in the furnace. It is also possible to water-cool the supply pipe 38 and mount it for rotation about its axis.
  • the sprayable refractory material in suitable dry or slurry form is fed to the supply pipe 38 and spray nozzle 39 by means of the hose 48 which leads from a mixer capable of delivering the refractory material in either form as desired.
  • a mixer capable of delivering the refractory material in either form as desired.
  • water may be mixed therewith by adding a 45 mixing nozzle at the point where the hose joins the pipe, as shown for example in copending application Ser. No. 402,203, filed Oct. 7, 1964.
  • the A-frame 43 may be dispensed with and the boom 37 mounted on a car running on rails used by other cars for various purposes.
  • the boom can also be mounted on a set of cross rails aflixed to the top of the car and so moved back and forth while the vertical motion may be taken care of by hydraulic pistons and cylinders or even screw jacks if desired.
  • the boom may even be sectionalized to allow it to be more readily transported from furnace to furnace or it may be folded up or back over itself.
  • the boom is to be made of stainless steel and may be water-cooled if desired for longer shooting periods.
  • FIG. 7 shows the various positions assumed by the Kaldo type basic oxygen furnace during the operating cycle.
  • the hot metal and scrap loading position is shown at 51, the blowing and lime and ore adding position at 52, and the pouring position at 53.
  • the furnace 50 is rotated about its axis and hence a more even wear pattern is established on the surface of the refractory lining.
  • the mouth of the furnace is fitted with a watercooled hood swingably mounted with the water-cooled oxygen lance 22 and water-cooled jacket 55 and lime and ore charging means 54 mounted therein.
  • the method of repairing the lining of this type of furnace is the same as the Linz-Donowitz depending on the type of program chosen.
  • the furnace can be rotated to a horizontal position where the boom can be employed after the hood is removed.
  • FIG. 8 is a cross sectional view of a basic oxygen converter furnace Illa showing the lining Ila and the trunmon 60 upon which it is tilted during operations.
  • the operation of this type of furnace is similar to the Linz- 1 i Donowitz and in the interest of brevity the procedure will not be repeated.
  • the normal furnace life has been from 175 to 250 heats during any one campaign. According to the present invention, the furnace life may be extended to from 450 to 500 heats or more, resulting in a greatly reduced refractory cost per ton of steel produced and insuring continuous production.
  • the refractory material used for the repair and coating of the furnace linings may be of any type so long as it is suitable and effective for the practice of the invention as herein described.
  • suitable refractory materials are listed below:
  • the coating composition consists of a mixture of chrome ore and magnesia but wherein the chrome ore predominates;
  • the coating composition consists of a mixture of chrome ore and magnesia but wherein the magnesia predominates.
  • a method for prolonging the life of the refractory lining of a furnace of the acid or basic converter type by spraying upon the furnace lining in its cylindrical barrel and conical top portions a series of protective coatings of refractory material in the form of a wet slurry which will adhere to said lining and become bonded thereto as it is applied comprising the step of operating the furnace throughout the life of the lining according .to a programmed schedule of steel producing operations and lining spraying operations, the lining spraying operations being performed by temporarily discontinuing the steel producing operations for repeated time intervals of sufficient duration to apply the protective refractory coatings in amounts sufficient to maintain the lining at a sufficient thickness to prevent failure thereof until the relining of the furnace becomes necessary, the total time elapsing in the steel producing operations before relining of the furnace being substantially greater than the total time elapsing in the lining spraying operations, whereby a maximum steel production may be obtained during the prolonged life of the lining.
  • a method for prolonging the life of the refractory lining of a furnace of the acid or basic converter type by spraying upon the furnace lining in its cylindrical barrel and conical top portions a series of protective coatings of refractory material in the form of a wet slurry which will adhere to said lining and become bonded thereto as it is applied comprising the step of operating the furnace throughout the life of the lining according to a programmed schedule of steel producing operations and lining spraying operations, the lining spraying operations being performed by temporarily discontinuing the steel producing operations for repeated time intervals of suificient duration to apply the protective refractory coatings in amounts sufiicient to maintain the lining against failure throughout .an initial period of furnace operation, the steel producing operations during said initial period being programmed to cause the establishment of a state of thermal equilibrium in the furnace lining only near the end of said initial period.
  • a method for prolonging the life of the refractory lining of a furnace of the acid or basic oxygen converter type by spraying upon the lining of the furnace a series of protective coatings of refractory material comprising the following steps:
  • step (b) during a further given period of time operating the furnace under substantially maximum daily steel producing conditions without spraying the lining during this further period, the amount of refractory coating material applied to the lining in step (a) being also sufiicient to protect the furnace lining against failure during this second step (b).
  • a method for prolonging the life of the refractory lining of a furnace of the acid or basic oxygen converter type by spraying upon the lining of the furnace a series of protective coatings of refractory material comprising the following steps:
  • step (b) during a further given period of time operating the furnace under substantially maximum daily steel producing conditions without spraying the lining l3 during this further period, the amount of refractory coating material applied to the lining in step (a) being also sufficient to protect the furnace lining against failure during this second step (b), and
  • a method for prolonging the life of the refractory linings of two furnaces of the acid or basic oxygen converter type which consists in operating concurrently two furnaces each according to the method set forth in claim 4 but pursuant to a schedule in which step (a) of one furnace coincides with step (c) of the other furnace and in which step (b) of one furnace coincides with the relining of the other furnace.
  • a method for prolonging the life of the refractory linings of high temperature furnaces of the acid or basic oxygen converter type which consists in operating two furnaces concurrently according to a programmed schedule which will insure a substantially constant maximum daily steel production at least equal substantially to the maximum daily steel producing capacity of one furnace when operated alone and which comprises the steps of operating one of said furnaces at a substantially maximum number of steel producing heats per day while the other one of said furnaces is being relined, and likewise operating the latter furnace after relining at a substantially maximum number of steel producing heats per day while the former furnace is being relined, and in the periods between the relining operations operating the two said furnaces alternately, one at a less than maximum number of steel producing heats per day, and the other also at a less than maximum number of steel producing heats per day, the total number of steel producing heats per day of both furnaces being at least equal substantially to the maximum number of heats per day of one furnace alone, and during said intervening periods between the relining operations, while the furnaces
  • a method for prolonging the life of the refractory linings of high temperature furnaces of the acid or basic oxygen converter type which consists in operating three furnaces concurrently according to a programmed schedule which will insure a substantially constant maximum daily steel production at least equal substantially to the maximum steel producing capacity of two furnaces when operated simultaneously and which comprises the steps of operating two furnaces each at a substantially maximum number of steel producing heats per day while a third furnace is being relined, then repeating this step for the relining of each of the other furnaces, and in the periods between the relining operations operating the three furnaces in rotation, one at a less than maximum number of steel producing heats per day and the other two also each at a less than maximum number of steel producing heats per day, the total number of steel producing heats per day of all three furnaces being at least equal substantially to the maximum number of steel producing heats per day of two furnaces when operated simultaneously at said maximum number, and during said intervening periods, while the furnaces are temporarily out of steel producing operation but still maintained at or near operating temperature, spray
  • any one furnace after being relined is first operated during a given period of time at a substantially less than maximum number of steel producing heats per day before being operated at the maximum number.
  • a method according to claim 10' wherein any one furnace after being operated at the maximum number of steel producing heats per day during the relining of another furnace, is next operated at a slightly less than maximum number before itself being relined.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
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US424071A 1965-01-07 1965-01-07 Method for prolonging the life of refractory linings in furnaces of the kaldo, linz-donowitz, de may or basic or acid converter types Expired - Lifetime US3351460A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
US424071A US3351460A (en) 1965-01-07 1965-01-07 Method for prolonging the life of refractory linings in furnaces of the kaldo, linz-donowitz, de may or basic or acid converter types
GB55062/65A GB1134699A (en) 1965-01-07 1965-12-29 Improvements in or relating to metallurgical converter furnaces
FR44161A FR1465796A (fr) 1965-01-07 1965-12-29 Procédé pour prolonger la vie des garnissages réfractaires dans les fours kaldo, linz donawitz, demay ou du genre convertisseur acide ou basique
GB26831/68A GB1134700A (en) 1965-01-07 1965-12-29 Improvements in or relating to apparatus for spraying coatings on the linings of metallurgical converter furnaces
ES0321460A ES321460A1 (es) 1965-01-07 1966-01-04 Un metodo para prolongar la duracion del revestimiento refractario de los hornos al oxigeno, de revestimiento basico para elevadas temperaturas, para incrementar la produccion total de acero de dichos hornos.
SE09511/68A SE365547B (fr) 1965-01-07 1966-01-05
DE1508235A DE1508235C3 (de) 1965-01-07 1966-01-05 Verfahren zur Erhöhung der Lebens dauer des Futters basisch ausgekleideter metallurgischer Ofen
JP66622A JPS52883B1 (fr) 1965-01-07 1966-01-07
BE674856D BE674856A (fr) 1965-01-07 1966-01-07
ES0327995A ES327995A1 (es) 1965-01-07 1966-06-16 Un aparato para aplicar una capa protectora de refractario al revestimiento refractario de un horno al oxigeno de revestimiento basico para elevadas temperaturas.
US663864A US3518330A (en) 1965-01-07 1967-08-28 Method for prolonging the life of the cone section of the refractory lining of a basic oxygen furnace of the kaldo type

Applications Claiming Priority (1)

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US424071A US3351460A (en) 1965-01-07 1965-01-07 Method for prolonging the life of refractory linings in furnaces of the kaldo, linz-donowitz, de may or basic or acid converter types

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US3351460A true US3351460A (en) 1967-11-07

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US (1) US3351460A (fr)
JP (1) JPS52883B1 (fr)
BE (1) BE674856A (fr)
DE (1) DE1508235C3 (fr)
ES (2) ES321460A1 (fr)
FR (1) FR1465796A (fr)
GB (2) GB1134699A (fr)
SE (1) SE365547B (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3460933A (en) * 1967-08-01 1969-08-12 Quigley Co Method of concurrently operating furnaces of the acid or basic converter types
US3518330A (en) * 1965-01-07 1970-06-30 Quigley Co Method for prolonging the life of the cone section of the refractory lining of a basic oxygen furnace of the kaldo type
FR2061542A1 (en) * 1969-05-22 1971-06-25 Quigley Co Steel production process
US4127626A (en) * 1975-06-24 1978-11-28 Kurosaki Refractories Co., Ltd. Method and apparatus for automatically repairing the lining of a furnace
US4222975A (en) * 1978-06-21 1980-09-16 Kirschke John A Apparatus and process for repairing underground gasoline tanks
US5772931A (en) * 1996-12-20 1998-06-30 Dofasco Inc. Slag coating process

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53115575U (fr) * 1977-02-22 1978-09-13
US4298378A (en) 1978-12-22 1981-11-03 Kawasaki Jukogyo Kabushiki Kaisha Rotary steel converter, method of making steel there-with and method of applying refractory lining to converter
CN104673955B (zh) * 2015-03-05 2016-11-23 山东钢铁股份有限公司 一种转炉停炉保温方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US405392A (en) * 1889-06-18 Process of repairing converter-bottoms
US1607554A (en) * 1924-01-18 1926-11-16 Allen S Davison Company Process of and apparatus for lining furnaces
US1675735A (en) * 1928-07-03 Ebanz stohb
US2124865A (en) * 1937-10-08 1938-07-26 Phelps Dodge Corp Patching interior surfaces of furnaces
US2358652A (en) * 1941-06-25 1944-09-19 Isaac A Nicholas Method of making bottoms of high temperature basic furnaces
GB579918A (en) * 1944-11-22 1946-08-20 Byers A M Co Improvements in or relating to the application of furnace linings
GB836472A (en) * 1957-09-23 1960-06-01 Low Moor Alloy Steelworks Ltd Improvements in the production or repair of refractory articles
US3093458A (en) * 1961-01-17 1963-06-11 Quigley Co Method of spraying multiple coatings of refractory compositions for hot furnace repair

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US405392A (en) * 1889-06-18 Process of repairing converter-bottoms
US1675735A (en) * 1928-07-03 Ebanz stohb
US1607554A (en) * 1924-01-18 1926-11-16 Allen S Davison Company Process of and apparatus for lining furnaces
US2124865A (en) * 1937-10-08 1938-07-26 Phelps Dodge Corp Patching interior surfaces of furnaces
US2358652A (en) * 1941-06-25 1944-09-19 Isaac A Nicholas Method of making bottoms of high temperature basic furnaces
GB579918A (en) * 1944-11-22 1946-08-20 Byers A M Co Improvements in or relating to the application of furnace linings
GB836472A (en) * 1957-09-23 1960-06-01 Low Moor Alloy Steelworks Ltd Improvements in the production or repair of refractory articles
US3093458A (en) * 1961-01-17 1963-06-11 Quigley Co Method of spraying multiple coatings of refractory compositions for hot furnace repair

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3518330A (en) * 1965-01-07 1970-06-30 Quigley Co Method for prolonging the life of the cone section of the refractory lining of a basic oxygen furnace of the kaldo type
US3460933A (en) * 1967-08-01 1969-08-12 Quigley Co Method of concurrently operating furnaces of the acid or basic converter types
FR2061542A1 (en) * 1969-05-22 1971-06-25 Quigley Co Steel production process
US4127626A (en) * 1975-06-24 1978-11-28 Kurosaki Refractories Co., Ltd. Method and apparatus for automatically repairing the lining of a furnace
US4222975A (en) * 1978-06-21 1980-09-16 Kirschke John A Apparatus and process for repairing underground gasoline tanks
US4325652A (en) * 1978-06-21 1982-04-20 Kirschke John A Apparatus and process for repairing underground gasoline tanks
US5772931A (en) * 1996-12-20 1998-06-30 Dofasco Inc. Slag coating process

Also Published As

Publication number Publication date
GB1134700A (en) 1968-11-27
BE674856A (fr) 1966-07-07
DE1508235A1 (de) 1972-03-30
GB1134699A (en) 1968-11-27
JPS52883B1 (fr) 1977-01-11
DE1508235C3 (de) 1973-10-18
SE365547B (fr) 1974-03-25
DE1508235B2 (de) 1973-03-29
FR1465796A (fr) 1967-01-13
ES321460A1 (es) 1966-11-01
ES327995A1 (es) 1967-04-01

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