CA1248349A - Movable sill furnace for heating iron metallurgy products - Google Patents
Movable sill furnace for heating iron metallurgy productsInfo
- Publication number
- CA1248349A CA1248349A CA000500818A CA500818A CA1248349A CA 1248349 A CA1248349 A CA 1248349A CA 000500818 A CA000500818 A CA 000500818A CA 500818 A CA500818 A CA 500818A CA 1248349 A CA1248349 A CA 1248349A
- Authority
- CA
- Canada
- Prior art keywords
- sills
- walking
- furnace
- axis
- stationary
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
- F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
- F27B9/20—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace
- F27B9/201—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace walking beam furnace
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Heat Treatments In General, Especially Conveying And Cooling (AREA)
- Tunnel Furnaces (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The invention relates to walking sill furnaces, in particular bilateral and/or mixed heating ones incorporating sills cooled with water or some other fluid, for heating iron metallurgy products, such as slabs, billets and blooms. The invention attenuates the depth of local cooling (black stripes) across the contact areas of the products to be heated with the stationary and walking cooled sills. According to the invention, the top surfaces of the sills whereon the products to be heated are made to rest either directly or indirectly by means of riders, follow -- as viewed in plan view -- a non-parallel pattern to the longitudinal axis of the furnace over at least part of the furnace length, and in particular an inclined pattern which may converge to and/or diverge from the furnace longitudi-nal axis, being preferably in the form of a number of inclined and staggered successive sections.
The invention relates to walking sill furnaces, in particular bilateral and/or mixed heating ones incorporating sills cooled with water or some other fluid, for heating iron metallurgy products, such as slabs, billets and blooms. The invention attenuates the depth of local cooling (black stripes) across the contact areas of the products to be heated with the stationary and walking cooled sills. According to the invention, the top surfaces of the sills whereon the products to be heated are made to rest either directly or indirectly by means of riders, follow -- as viewed in plan view -- a non-parallel pattern to the longitudinal axis of the furnace over at least part of the furnace length, and in particular an inclined pattern which may converge to and/or diverge from the furnace longitudi-nal axis, being preferably in the form of a number of inclined and staggered successive sections.
Description
~2~83~9 The present invention relates to walking sill furnaces, particularly bilateral andtor mixed heating furnaces having sills cooled with either water or some other fluid, as used for heating iron metallurgy products, such as slabs, billets and blooms.
With furnaces o~ this type, the products placed therein are stepped forward while resting with their bottom sides alternately on the stationary and walking sills. In prior furnaces, the top surfaces of the stationary and walking sills follow, when viewed in plan view, a parallel pattern to the furnace longitudinal axis and to the infeed direction of -the products through the furnace. Consequently, the products always bear on the sills with the same contact areas of their bottom sides. For this reason, and especially with bila~eral heating furnaces where the sills are cooled with either water or some other fluid and are, therefore, comparatively cold, the areas of rest of the products onto the sills show on drawing them out of the furnace -- owing to their contacting the sills at fixed locations and to shielding from the burners ~- a lower tempera-ture than the average temperature of remaining product, thusforming so-called ~black stripes". These colder black stripes cause problems with the rolling of the heated products, such as, for example, variations in the thickness of flat rolled stock and seamless tubes.
In order to at~enuate the problems due to blacX
stripes, it is k~own to install on the cooled sills :
::
:
With furnaces o~ this type, the products placed therein are stepped forward while resting with their bottom sides alternately on the stationary and walking sills. In prior furnaces, the top surfaces of the stationary and walking sills follow, when viewed in plan view, a parallel pattern to the furnace longitudinal axis and to the infeed direction of -the products through the furnace. Consequently, the products always bear on the sills with the same contact areas of their bottom sides. For this reason, and especially with bila~eral heating furnaces where the sills are cooled with either water or some other fluid and are, therefore, comparatively cold, the areas of rest of the products onto the sills show on drawing them out of the furnace -- owing to their contacting the sills at fixed locations and to shielding from the burners ~- a lower tempera-ture than the average temperature of remaining product, thusforming so-called ~black stripes". These colder black stripes cause problems with the rolling of the heated products, such as, for example, variations in the thickness of flat rolled stock and seamless tubes.
In order to at~enuate the problems due to blacX
stripes, it is k~own to install on the cooled sills :
::
:
- 2 -': ' ' ' . ' .' ' ,.
` '~ ` - :
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; ~ o~ ff:b~e sill furnaces of the cited type, spaced apart riders formed from a ~pecial alloy, whereon the products introduced into the furnace are made to rest. Such riders act as spacers between the cooled sills and heated products, and by virtus of the fact that the special alloy used in their construction, can reach, at their surfaces in contact wlth the overlying products, much higher temperatures than those o~ the cooled sills, while retaining ~t such higher temperatures optimum mechanical characteristic~ in all cases effective to prevent upsetting phenomena due to`the weight of the products. The riders, however, have proved to be inadequate to eliminate the black stripes, the temperature whereof, on withdrawal from the furnace is still appreciably lower than the average temperature of the heated products in spite of the riders.
~ hus, to further reduce ~o~nation of the black stripes, movable sill furnaces have been proposed wherein the stationary and movable sills maintain their top surfaces parallel to the flrnac~s' longitudinal axis, and accordingly, to the direction of advance of the products to be heated, but are split in two transversely staggered successive sections.
Conssquently, the products change their areas of rest onto the sills, substantially midway through the furnace. ~ven this prior approach, while af~ording a limited increase in the temperature of the black stripes, has proved inadequate to obviate the problems of the black stripes, because the products being heated still bear for too long a tlme on the `
33~
sllls wlth the same areas of contact, thereby local coolIng at such rest areas reaches conslderable depth.
The Inventlon provldes for a further attenuatlon of the problem of the aforesaid black strlpes whlch form on Iron metal-lurgy products (slabs, blllets, blooms, and the llke) belng heated In walklng slll furnaces, and Is partlcularly dlrected to slgnl f Icantly decrease the depth of local coollng In Iron metal-lurgy products at thelr areas of rest on the statlonary and walk-Ing sllls, In partlcular cooled sllls. The Inventlon Is based onthe recognltlon that It Is hlghly Important, especlally wlth walklng slll heatlng furnaces whlch supply rolling mllls for flat products, such as strlps to have In the heated slabs or blllets black strlpes whlch although shallow, are broader.
1~
Accordlng to the present Inventlon there Is provlded In a walklng slll f u rnace f or heatlng metallurglcal artlcles and havlng a longltudlnal extenslon and a longltudlnal heatlng cham-ber wlth a longltudlnal mld-axls thereln and a plurallty of long-Itudlnally extendlng and Juxtaposed alternatlngly arranged stat-lonary and walklng sllls havlng duct formatlons provlded thereln for a coolIng fluld and wlth an Inlet end at one extremlty of the furnace and an outlet end at an opposlte extremlty thereof longl-tudlnally spaced apart from sald one extremlty and deflnlng a downstream dlrectlon dlrected from sald Inlet end towards sald outlet end, arranged at each slde of sald longltudlnal mld-axls at least one of sald longltudlnally extendlng statlonary sllls havlng successlve statlonary sectlons thereof extendlng In a dlrectlon havlng a convergent Incllnatlon towards sald longltu-dlnal mld-axls ~ollowlng sald downstream dlrectlon and at least one of sald longltudlnally extendlng walklng sllls havlng suc-cesslve walklng sectlons thereof arranged In spaced slde-by-slde relatlonshlp to sald statlonary sectlons and parallel thereto wlth a convergent Incllnatlon towards sald longltudlnal mld-axls followlng sald downstream dlrectlon, arranged at each slde of sa Id I ong Itudlnal mld-axls at least another of sald longltudl-,~ ~
:
:
33~
nally extendlng statlonary sllls la~erally a~ a dlstance from sald one longltudlnally extendlng slll and havlng other succes-slve statlonary sectlons thereof extendlng In a dlrectlon havlng a dlvergent Incllnatlon wlth respect to sald longltudlnal mld-axls followlng sald downstream dlrectlon and at least another ofsald longltudlnally extendlng walklng sllls havlng other suc-cesslve walklng sectlons thereof arranged In spaced slde-by-slde relatlonshlp to sald other successlve statlonary sectlons and parallel thereto wlth a dlvergent Incllnatlon wlth respect to sald longltudlnal mld-axls followlng sald downstream dlrectlon.
In a partlcular embodlment of the present Inventlon sald successlve statlonary sectlons and sald successlve walklng sectlons both havlng a convergent InclInatlon towards sald longl-tudlnal mld-axls are arranged remote from sald longltudlnal mld-axls and sald other successlve statlonary sectlons and sald other successlve walklng sectlons both havlng a dlvergent Incllnatlon wlth respect to sald longltudlnal mld-axls are arranged nearer to sald longltudlnal mld-axls than sald successlve statlonary and successlve walklng sectlons.
Thus, accordlng to the Inventlon the top surfaces of the statlonary and walklng sllls whereon the products to be heated rest dlrectly or Indlrectly vla rlders, follow, when vlewed In plan vlew, over at least a part of the furnace length a non-parallel Incllnatlon wlth respect to the longltudlnal axls of the furnace, and speclfIcally a convergent and/or dlvergent Incllnatlon wlth respect to the longltudlnal mld-axls of the fur-nace, and accordlngly, wlth respect to the dlrectlon of advance of the products through the ~urnace.
The top surface of each statlonary or walklng slll Is - 4a -.
: :
~Z~33~
composed of several successive sections, of which at least one, when viewed in plan view, has inclination with respect to the ~urnace longitudinal axis bu-t is con-tained withln a rela-tively narrow band subs-tantially parallel to the furnace axis. The individual successive sections of the top surface of each sill are inclined in the same direction, diverging or converging with respect to the longitudinal mid-axis of the furnace and are staggered from one another. In another embodiment, the individ-ual successive sections of the top surface of each sill are inclined, specifically in an alternate fashion, in opposite directions which may diverge from or converge toward the longitudinal axis of the furnace, e.g. such as to form a zigzagging line when viewed in plan view.
In at least one section of the furnace, the corresponding inclined sections of the top surfaces of the stationary and walking sills may be convergent to, or divergent from, the furnace longitudinal mid-axis, or may be part-convergent and part-divergent, in particular alternately convergent and divergent with respect to said longitudinal mid-axis.
The successive sections of the top surface of each sill may be rectilinear or curved, and elther separated from or connected to each other. In general, the top surface of each sill, whether stationary or movable, may present -- in plan view -- the development of either a broken, continuous, or discontinu-ous line, comprising at least one, and preferably several sections, inclined with respect to the longitudinal axis o the furnace, or the development of any continuous or discontinuous curved line, in particular one with at least one twisting or unduIating portion.
In all cases, according to this invention, the areas of the products being heated bearing on the top surfa~es of the . .
~Z4B3~
stationary and walking sills are arranged to be constantly varied as the products are being fed through the furnace. Accordingly, the time period that the products being heated will rest onto the cooled sills with the same contact areas of their boktom surfaces is reduced, thereby the depth of the black stripes is significantly decreased and their temperature increased. Thus, the problems brought about by the black stripes are eliminated or at least minimized. In addition to this main advantage, the invention also affords a decreased length of the furnace region reserved for making the temperature of the products being heated uniform, and therefore, a decreased overall length of the furnace for a given output and quality (uniform temperature) of the heating of the iron metallurgy products, or for the same furnace length, improved quality of the heated products.
The present invention, and the advantages afforded thereby, will be further illustrated in a preferred embodiment thereof, with reference to the accompanying drawings where:-Figure 1 is a schematic horizontal cross-sectional view of a walking sill furnace according to one embodiment of the invention, with the sills shown in top plan view;
Figure 2 and 3 show to an enlarged scale a cross-section taken through one half of the furnace of Figure 1, wherein walking sills intermix with stationary sills and are shown in a lowered (Figure 2) position and raised (Figure 3) position;
Figure 4 is a sectional view similar to Figures 2 and 3 taken through a modified embodiment of the furnace, wherein each of the furnace halves has two walking sills included between two stationary sills, with the walking sills in their lowered position; and .
- : '' "
.: , , ', .
. .
` '~ ` - :
~Z483~
; ~ o~ ff:b~e sill furnaces of the cited type, spaced apart riders formed from a ~pecial alloy, whereon the products introduced into the furnace are made to rest. Such riders act as spacers between the cooled sills and heated products, and by virtus of the fact that the special alloy used in their construction, can reach, at their surfaces in contact wlth the overlying products, much higher temperatures than those o~ the cooled sills, while retaining ~t such higher temperatures optimum mechanical characteristic~ in all cases effective to prevent upsetting phenomena due to`the weight of the products. The riders, however, have proved to be inadequate to eliminate the black stripes, the temperature whereof, on withdrawal from the furnace is still appreciably lower than the average temperature of the heated products in spite of the riders.
~ hus, to further reduce ~o~nation of the black stripes, movable sill furnaces have been proposed wherein the stationary and movable sills maintain their top surfaces parallel to the flrnac~s' longitudinal axis, and accordingly, to the direction of advance of the products to be heated, but are split in two transversely staggered successive sections.
Conssquently, the products change their areas of rest onto the sills, substantially midway through the furnace. ~ven this prior approach, while af~ording a limited increase in the temperature of the black stripes, has proved inadequate to obviate the problems of the black stripes, because the products being heated still bear for too long a tlme on the `
33~
sllls wlth the same areas of contact, thereby local coolIng at such rest areas reaches conslderable depth.
The Inventlon provldes for a further attenuatlon of the problem of the aforesaid black strlpes whlch form on Iron metal-lurgy products (slabs, blllets, blooms, and the llke) belng heated In walklng slll furnaces, and Is partlcularly dlrected to slgnl f Icantly decrease the depth of local coollng In Iron metal-lurgy products at thelr areas of rest on the statlonary and walk-Ing sllls, In partlcular cooled sllls. The Inventlon Is based onthe recognltlon that It Is hlghly Important, especlally wlth walklng slll heatlng furnaces whlch supply rolling mllls for flat products, such as strlps to have In the heated slabs or blllets black strlpes whlch although shallow, are broader.
1~
Accordlng to the present Inventlon there Is provlded In a walklng slll f u rnace f or heatlng metallurglcal artlcles and havlng a longltudlnal extenslon and a longltudlnal heatlng cham-ber wlth a longltudlnal mld-axls thereln and a plurallty of long-Itudlnally extendlng and Juxtaposed alternatlngly arranged stat-lonary and walklng sllls havlng duct formatlons provlded thereln for a coolIng fluld and wlth an Inlet end at one extremlty of the furnace and an outlet end at an opposlte extremlty thereof longl-tudlnally spaced apart from sald one extremlty and deflnlng a downstream dlrectlon dlrected from sald Inlet end towards sald outlet end, arranged at each slde of sald longltudlnal mld-axls at least one of sald longltudlnally extendlng statlonary sllls havlng successlve statlonary sectlons thereof extendlng In a dlrectlon havlng a convergent Incllnatlon towards sald longltu-dlnal mld-axls ~ollowlng sald downstream dlrectlon and at least one of sald longltudlnally extendlng walklng sllls havlng suc-cesslve walklng sectlons thereof arranged In spaced slde-by-slde relatlonshlp to sald statlonary sectlons and parallel thereto wlth a convergent Incllnatlon towards sald longltudlnal mld-axls followlng sald downstream dlrectlon, arranged at each slde of sa Id I ong Itudlnal mld-axls at least another of sald longltudl-,~ ~
:
:
33~
nally extendlng statlonary sllls la~erally a~ a dlstance from sald one longltudlnally extendlng slll and havlng other succes-slve statlonary sectlons thereof extendlng In a dlrectlon havlng a dlvergent Incllnatlon wlth respect to sald longltudlnal mld-axls followlng sald downstream dlrectlon and at least another ofsald longltudlnally extendlng walklng sllls havlng other suc-cesslve walklng sectlons thereof arranged In spaced slde-by-slde relatlonshlp to sald other successlve statlonary sectlons and parallel thereto wlth a dlvergent Incllnatlon wlth respect to sald longltudlnal mld-axls followlng sald downstream dlrectlon.
In a partlcular embodlment of the present Inventlon sald successlve statlonary sectlons and sald successlve walklng sectlons both havlng a convergent InclInatlon towards sald longl-tudlnal mld-axls are arranged remote from sald longltudlnal mld-axls and sald other successlve statlonary sectlons and sald other successlve walklng sectlons both havlng a dlvergent Incllnatlon wlth respect to sald longltudlnal mld-axls are arranged nearer to sald longltudlnal mld-axls than sald successlve statlonary and successlve walklng sectlons.
Thus, accordlng to the Inventlon the top surfaces of the statlonary and walklng sllls whereon the products to be heated rest dlrectly or Indlrectly vla rlders, follow, when vlewed In plan vlew, over at least a part of the furnace length a non-parallel Incllnatlon wlth respect to the longltudlnal axls of the furnace, and speclfIcally a convergent and/or dlvergent Incllnatlon wlth respect to the longltudlnal mld-axls of the fur-nace, and accordlngly, wlth respect to the dlrectlon of advance of the products through the ~urnace.
The top surface of each statlonary or walklng slll Is - 4a -.
: :
~Z~33~
composed of several successive sections, of which at least one, when viewed in plan view, has inclination with respect to the ~urnace longitudinal axis bu-t is con-tained withln a rela-tively narrow band subs-tantially parallel to the furnace axis. The individual successive sections of the top surface of each sill are inclined in the same direction, diverging or converging with respect to the longitudinal mid-axis of the furnace and are staggered from one another. In another embodiment, the individ-ual successive sections of the top surface of each sill are inclined, specifically in an alternate fashion, in opposite directions which may diverge from or converge toward the longitudinal axis of the furnace, e.g. such as to form a zigzagging line when viewed in plan view.
In at least one section of the furnace, the corresponding inclined sections of the top surfaces of the stationary and walking sills may be convergent to, or divergent from, the furnace longitudinal mid-axis, or may be part-convergent and part-divergent, in particular alternately convergent and divergent with respect to said longitudinal mid-axis.
The successive sections of the top surface of each sill may be rectilinear or curved, and elther separated from or connected to each other. In general, the top surface of each sill, whether stationary or movable, may present -- in plan view -- the development of either a broken, continuous, or discontinu-ous line, comprising at least one, and preferably several sections, inclined with respect to the longitudinal axis o the furnace, or the development of any continuous or discontinuous curved line, in particular one with at least one twisting or unduIating portion.
In all cases, according to this invention, the areas of the products being heated bearing on the top surfa~es of the . .
~Z4B3~
stationary and walking sills are arranged to be constantly varied as the products are being fed through the furnace. Accordingly, the time period that the products being heated will rest onto the cooled sills with the same contact areas of their boktom surfaces is reduced, thereby the depth of the black stripes is significantly decreased and their temperature increased. Thus, the problems brought about by the black stripes are eliminated or at least minimized. In addition to this main advantage, the invention also affords a decreased length of the furnace region reserved for making the temperature of the products being heated uniform, and therefore, a decreased overall length of the furnace for a given output and quality (uniform temperature) of the heating of the iron metallurgy products, or for the same furnace length, improved quality of the heated products.
The present invention, and the advantages afforded thereby, will be further illustrated in a preferred embodiment thereof, with reference to the accompanying drawings where:-Figure 1 is a schematic horizontal cross-sectional view of a walking sill furnace according to one embodiment of the invention, with the sills shown in top plan view;
Figure 2 and 3 show to an enlarged scale a cross-section taken through one half of the furnace of Figure 1, wherein walking sills intermix with stationary sills and are shown in a lowered (Figure 2) position and raised (Figure 3) position;
Figure 4 is a sectional view similar to Figures 2 and 3 taken through a modified embodiment of the furnace, wherein each of the furnace halves has two walking sills included between two stationary sills, with the walking sills in their lowered position; and .
- : '' "
.: , , ', .
. .
3~5~
Figure 5 is a vertical cross-section taken longitudinally through the end portion of the walking sill furnace.
Shown in the drawings is a walking slll furnace which will be discussed hereinafter in connection with its use to heat slabs B, blooms, and billets, for example, without excluding, however, its use with other comparable products.
In the Figures, the numeral 1 denotes the stationary sills and 2 the walking sills of the furnace. Over at least a part of the furnace length, both the stationary sills 1 and walking sills 2 have a tubular construction and are cooled by the circulation of water or some other fluid. The walking sills 2 can be raised and lowered to alternatively move into a raised position (Figure 3) where they pro~ec-t upwards from the support-ing surface defined by the stationary sills 1 and from where the slabs B are advanced, and into a lowered position (Figures 2 and
Figure 5 is a vertical cross-section taken longitudinally through the end portion of the walking sill furnace.
Shown in the drawings is a walking slll furnace which will be discussed hereinafter in connection with its use to heat slabs B, blooms, and billets, for example, without excluding, however, its use with other comparable products.
In the Figures, the numeral 1 denotes the stationary sills and 2 the walking sills of the furnace. Over at least a part of the furnace length, both the stationary sills 1 and walking sills 2 have a tubular construction and are cooled by the circulation of water or some other fluid. The walking sills 2 can be raised and lowered to alternatively move into a raised position (Figure 3) where they pro~ec-t upwards from the support-ing surface defined by the stationary sills 1 and from where the slabs B are advanced, and into a lowered position (Figures 2 and
4) where they are dropped below the supporting surface defined by the stationary sills 1 and deposit the slabs B onto the station-ary sills 1. Further, the walking sills 2 may be shifted horizontally, forward in the direction of the F in Figure 1 when in their raised condition, the feed forward by one step the slabs B, and rearward in the opposite direction to the arrow F in Figure 1 when in their lowered condition, to make ready for the next forward stepping of the slabs B. These movements of the walking sills may be provided in any suitable way, e.g. in the following known way.
The walking sills 2 are carried on tubular pillars 3, also cooled by circulating water or any other suitable fluid therethrough and firmly mounted on a movable lower bed 4 which is made to rest, through carriages~5, onto fixed inclined surfaces 6 made fast with respective foundations 7. The carriages 5 are interconnected by means of longitudinal rods ~ which are : ~ :
:~
, . ... . . . . . ~ .. .
:
- - ,.
~ : .
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articulated by means of a cross-piece 9, to any actuator .such as the piston rod 111 of an oil-operat0d cylinder 11 oscillably ~ournalled at 211. The carriages 5 rest on the inclined surfaces 6 through running wheels 105, and have supporting idler ~ .
: :
- 8 - ~
- . . . ..
,, ~ '` `; ` ' ~.
`
83~9 .
_ g _ wheels 205, whereon the bed 4 is arranged to rest slidably with the intermediary of longitudinal rail~
~1 104. The vertical up and down mo~ement of the sills 2 is accomplished by moving the carriages 5 horizontally on the inclined surfaces 6 through the oil-operated cylinder 11. ~he horizontal, lengthwise back and forth movement of the ~ sills 2 is provided by another oil-operated cylinder 12 which is mounted for oscillation at 112 on a holder stand 107 secured to the ~oundation work and has its piston rod 212 linked to the movable bed 4.
The stationary sills 1 are also carried on tubular pillars 103 which are,cooled by circulating water or some other suitable fluid therethrough,and affixed to the bottom 113 of the furnace. At the movable sills 2, the bottom or hearth 113 is completed with bottom portions 13 which are attached to the lower bed 4 and move along therewith.
Burners 14,15 are provided both above and below the sills 1,2, thereby providing for a bilateral heating of the slabs B. The upper burners 14 are located preferably on the furnace roof, whilst the lower burners 15 may be positioned on the end walls, as shown, and/or the side walls. The slabs B to be heated are fed into the furnace by means of a roller runway 17 at the inlet end. At least some of the stationary 1 and movable 2 sills extend as far as said roller runway 17~ and the slabs B are transferred from the roller runwa~ 17 to the sills by means of pushers (not shown).~Provlded at the opposite, outlet ' .
~2483~a end of the furnace is a front withdrawal door 18 through which, with the assistance of a specially arranged withdrawal machine (Not shown), the heated slabs B are taken out of the furnace and deposited onto the external roller runway 19 for transferrment to the rolling mill. The slabs B are carried on the sills 1,2 with the interposition of spaced apart blocks 16, also termed "ridersll, which are fastened to the sills 1,2 and formed, for example, from a special cobalt alloy.
Each stationary 1 or walking 2 sill is composed of a number of successive sections 101 or 102 which, when viewed in plan view, are inclined to the longitudinal axis A-A of the furnace, and hence, to the direction F of advance of the slabs B.
In the embodiment shown, the successive sections 101 or 102 of each stationary sill 1 or walking sill 2 are straight and staggered to one another so as to fall, again in plan view, within a comparatively narrow band extending in the longitudinal direction of the furnace. In the embodiment of Figures 1,2 and 3, in each section of the furnace, the respective sections 101,102 of the three sills located on each side of the furnace (i.e. two stationary sills 1 and one intervening walking sill 2~
are laid to converge toward the mid-longitudinal axis A-A of the furnace, whilst the secticns (101,102) of the four middle sills (i.e. two center sills 1 flanked by two walking sills 2) are set 2s divergent from the longitudinal mid-axis A-A of the furnace relatively to the direction F of forward movement of the slabs B.
In the embodiment of Figure 4, the furnace comprises two pairs of walking sills 2, provided on the two sides of a middle pair of stationary sills 1 and flanked on each side of the furnace by a stationary sill 1. In this case, ln each furnace section, the respective sections of the sills 1,2 are alternately convergent and divergent with respect to the longitudinal mid-axis of the furnace.
--: 10 --.
' .
-, , ,
The walking sills 2 are carried on tubular pillars 3, also cooled by circulating water or any other suitable fluid therethrough and firmly mounted on a movable lower bed 4 which is made to rest, through carriages~5, onto fixed inclined surfaces 6 made fast with respective foundations 7. The carriages 5 are interconnected by means of longitudinal rods ~ which are : ~ :
:~
, . ... . . . . . ~ .. .
:
- - ,.
~ : .
L8~
articulated by means of a cross-piece 9, to any actuator .such as the piston rod 111 of an oil-operat0d cylinder 11 oscillably ~ournalled at 211. The carriages 5 rest on the inclined surfaces 6 through running wheels 105, and have supporting idler ~ .
: :
- 8 - ~
- . . . ..
,, ~ '` `; ` ' ~.
`
83~9 .
_ g _ wheels 205, whereon the bed 4 is arranged to rest slidably with the intermediary of longitudinal rail~
~1 104. The vertical up and down mo~ement of the sills 2 is accomplished by moving the carriages 5 horizontally on the inclined surfaces 6 through the oil-operated cylinder 11. ~he horizontal, lengthwise back and forth movement of the ~ sills 2 is provided by another oil-operated cylinder 12 which is mounted for oscillation at 112 on a holder stand 107 secured to the ~oundation work and has its piston rod 212 linked to the movable bed 4.
The stationary sills 1 are also carried on tubular pillars 103 which are,cooled by circulating water or some other suitable fluid therethrough,and affixed to the bottom 113 of the furnace. At the movable sills 2, the bottom or hearth 113 is completed with bottom portions 13 which are attached to the lower bed 4 and move along therewith.
Burners 14,15 are provided both above and below the sills 1,2, thereby providing for a bilateral heating of the slabs B. The upper burners 14 are located preferably on the furnace roof, whilst the lower burners 15 may be positioned on the end walls, as shown, and/or the side walls. The slabs B to be heated are fed into the furnace by means of a roller runway 17 at the inlet end. At least some of the stationary 1 and movable 2 sills extend as far as said roller runway 17~ and the slabs B are transferred from the roller runwa~ 17 to the sills by means of pushers (not shown).~Provlded at the opposite, outlet ' .
~2483~a end of the furnace is a front withdrawal door 18 through which, with the assistance of a specially arranged withdrawal machine (Not shown), the heated slabs B are taken out of the furnace and deposited onto the external roller runway 19 for transferrment to the rolling mill. The slabs B are carried on the sills 1,2 with the interposition of spaced apart blocks 16, also termed "ridersll, which are fastened to the sills 1,2 and formed, for example, from a special cobalt alloy.
Each stationary 1 or walking 2 sill is composed of a number of successive sections 101 or 102 which, when viewed in plan view, are inclined to the longitudinal axis A-A of the furnace, and hence, to the direction F of advance of the slabs B.
In the embodiment shown, the successive sections 101 or 102 of each stationary sill 1 or walking sill 2 are straight and staggered to one another so as to fall, again in plan view, within a comparatively narrow band extending in the longitudinal direction of the furnace. In the embodiment of Figures 1,2 and 3, in each section of the furnace, the respective sections 101,102 of the three sills located on each side of the furnace (i.e. two stationary sills 1 and one intervening walking sill 2~
are laid to converge toward the mid-longitudinal axis A-A of the furnace, whilst the secticns (101,102) of the four middle sills (i.e. two center sills 1 flanked by two walking sills 2) are set 2s divergent from the longitudinal mid-axis A-A of the furnace relatively to the direction F of forward movement of the slabs B.
In the embodiment of Figure 4, the furnace comprises two pairs of walking sills 2, provided on the two sides of a middle pair of stationary sills 1 and flanked on each side of the furnace by a stationary sill 1. In this case, ln each furnace section, the respective sections of the sills 1,2 are alternately convergent and divergent with respect to the longitudinal mid-axis of the furnace.
--: 10 --.
' .
-, , ,
Claims (2)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a walking sill furnace for heating metallurgical articles and having a longitudinal extension and a longitudinal heating chamber with a longitudinal mid-axis therein and a plurality of longitudinally extending and juxtaposed alternatingly arranged stationary and walking sills having duct formations provided therein for a cooling fluid and with an inlet end at one extremity of the furnace and an outlet end at an opposite extremity thereof longitudinally spaced apart from said one extremity and defining a downstream direction directed from said inlet end towards said outlet end, arranged at each side of said longitudinal mid-axis at least one of said longitudinally extending stationary sills having successive stationary sections thereof extending in a direction having a convergent inclination towards said longitudinal mid-axis following said downstream direction and at least one of said longitudinally extending walking sills having successive walking sections thereof arranged in spaced side by side relationship to said stationary sections and parallel thereto with a convergent inclination towards said longitudinal mid-axis following said downstream direction, arranged at each side of said longitudinal mid-axis at least another of said longitudinally extending stationary sills laterally at a distance from said one longitudinally extending sill and having other successive stationary sections thereof extending in a direction having a divergent inclination with respect to said longituidnal mid-axis following said downstream direction and at least another of said longituidnally extending walking sills having other successive walking sections thereof arranged in spaced side by side relationship to said other successive stationary sections and parallel thereto with a divergent inclination with respect to said longitudinal mid-axis following said downstream direction.
2. A furnace according to claim 1, wherein said successive stationary sections and said successive walking sections both having a convergent inclination towards said longitudinal mid-axis are arranged remote from said longitudinal mid-axis and said other successive stationary sections: and said other successive walking sections both having a divergent inclination with respect to said longitudinal mid-axis are arranged nearer to said longitudinal mid-axis than aid successive stationary and successive walking sections.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT8512423A IT1186820B (en) | 1985-02-01 | 1985-02-01 | MOBILE LONGHERONI OVEN FOR THE HEATING OF STEEL PRODUCTS |
| IT12423A/85 | 1985-02-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1248349A true CA1248349A (en) | 1989-01-10 |
Family
ID=11139973
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000500818A Expired CA1248349A (en) | 1985-02-01 | 1986-01-31 | Movable sill furnace for heating iron metallurgy products |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1248349A (en) |
| ES (1) | ES8701848A1 (en) |
| IT (1) | IT1186820B (en) |
-
1985
- 1985-02-01 IT IT8512423A patent/IT1186820B/en active
-
1986
- 1986-01-31 CA CA000500818A patent/CA1248349A/en not_active Expired
- 1986-01-31 ES ES551479A patent/ES8701848A1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| IT1186820B (en) | 1987-12-16 |
| ES8701848A1 (en) | 1986-12-16 |
| ES551479A0 (en) | 1986-12-16 |
| IT8512423A0 (en) | 1985-02-01 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |