CA1165114A

CA1165114A - Heat exchange devices for cooling the wall and refractory of a blast furnace

Info

Publication number: CA1165114A
Application number: CA000374459A
Authority: CA
Inventors: Francois Touze
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-04-02
Filing date: 1981-04-02
Publication date: 1984-04-10
Also published as: LU83275A1; ES500981A0; DE3113354C2; DE3113354A1; GB2073387B; IN153696B; GB2073387A; FR2479852A2; JPS56155378A; MX152034A; BE888087R; AR230844A1; ES8205863A2; BR8101976A; IT8109374A0; IT1167858B; JPH0243116B2; FR2479852B2

Abstract

ABSTRACT
The invention concerns heat exchange devices for cooling the wall and the refractory of a blast furnace. Such a device, constituting a cooling box, comprises :
- a closed enclosure, elongated and having a shape of revolution or substantially of revolution, this enclosure comprising an outer end and an inner end, - an axial capacity defining with said enclosure an annu-lar capacity, this axial capacity comprising an outer end and an inner end, - a supply orifice for feeding a cooling liquid into the axial capacity through its outer end, - and a discharge orifice for discharging the cooling liquid from the annular capacity through the outer end of the enclosed enclosure - deflector means provided between the inner end of the axial capacity and the inner end of the enclosed enclosure, these deflector means being arranged so as to impart to the whole of the flow of the cooling liquid :
- an axial component, directed towards the inner end of the enclosed enclosure, for cooling the central part of the inner end of this enclosure, - a radial component for cooling the rest of the inner end of the enclosed enclosure, - an axial component directed towards the outer end of the closed enclosure for causing the return of the cooling liquid, - and a tangential component for cooling the part of revolution of the closed enclosure.

Description

"` ~DB5~.4 The nresent invention relates to heat exchangers used, for example, for cooling the wall and the refractory of a blast furnace, and more narticularly to cooling boxes (intended to be incorporated in the refractory) and cooling plates (for ~lacing between the refractory and the metal casing).
One aim of the invention is to provide a heat exchanger which uses only a small quantity of cooling liquid er unit of time.
Another aim of the invention is to provide a heat exchanger in which a cooling liquid removes, from the surroundings, a large ~uantity of heat per uni-t time.
Another aim of the invention is to ~rovide a heater exchan~er in which nressure losses during circulation of coolinq li~uid are low.
Another aim of the invention is to nrovide a heat exchange device which only needs for its manufacture a small ~uantity o~ material, so that, even if recourse is had to an expensive material, such as cop~er, the cost of the device remains low.
Finally another aim of the inven-tion is to obtain a high coolant sneed on the ~arts to be the most intense-ly cooled, thus makinq the heat exchange at these parts hi~h~
In a first asnect of the invention, there is provid-ed a heat exchanger comprising a body shaped substantial-ly as a body of revolution and hàving first and second end walls and a curved wall extending therebetween, the first end wall and the curved wall being heat-transfer 1 ~ 6~ 4 walls and at least the curved wall having a substantially smooth inner surface, a heat-transfer fluid supply ~ort adjacent to the first end wall and ada~ted for tangential-ly supplying heat--transfer fluid into the body, a heat-transfer ~luid discharge port adjacent to the ~eriphery of the second end wall and adapted for tangentially discharging the heat-transfer fluid from the body, whereby in use, tanqentially sup~lie~ heat-transfer fluid flows from the sup~ly ~ort outwardly and with a rotation-al motion about the axis of the body over the inner surface of the first end wall and thence, with a free helical motion around the axis of the body, over the inner surface of the curved wall to the discharge ~ort.
With the arranqement, in use, the heat-transfer fluid strikes the inner face o~ the first end wall of the body, which is situated, for exampIe, in a hot ~art o a blast furnace, at high s~eed and cooling there takes place with ~reat e~ficiency.
Furthermore, it is ensured that the whole of the inner surface of the first end wall of the body is bathed by the heat-exchange fluid and that this fluid, once set in motion in helical rotation, is brought to the other end of the body while bathing the whole of the curved wall.
Finally, because of the even helical movement im~arted to the heat-exchange gluid, it is ensured that the liquid bathes the walls of the enclosure continuous-ly and without any swirling movement and that thereby ~B~

the cooling efficiency obtained is high.
It is preferable that, the heat-transfer fluid flows with a rotational speed com~onent which is about ten times greater, at the discharge ~ort, than an axial component directed towards the second end wall of the body.
Advantageously, deflecting members are provided for deflecting the heat transfer fluid supplied by the supply port to flow outwardly and with said rotational motion.
Conveniently, the fluid deflecting members comprise curved vanes on the inner surface of the first end wall.
According to another aspect of the invention, there is provided a heat exchanger com~rising a body shaped substantially as a body of revoLution and having first and second end walls and u curved wall extending there-between, the first end wall being a heat transfer wall, a supply port and a discharge port for heat transfer fluid, the ports being spaced apart radially, the su~ply port being adapted for tangentially supplying the heat transfer fluid into the body and the discharge ~ort being adapted for tangentially discharging the heat-transfer for fluid from the body so that, in use, the fluid flows between the ports in a spiral path over the inner surface of the first end wall, the body having no internal obstacle to such flow.
It is advantageous for the supply port and the discharge port to be respectively adjacent the periphery and the centre of the first end wall.

t ~ ~

Some particular arrangements may be applicable to these cooling devices so as to make them suitable for special ap~lications.
For this, in a first embodiment, it is envisaged that, with the means for tangential injection of the liquid opening tangentially into the enclosure at the periphery or in the vicinity of the periphery thereof and with the means for tangential discharge of liquid situated in the center of the enclosure, the tangential lo discharge means comprise at least one assembly of deflecting means situated in the center of the enclosure and a duct opening into a face of the enclosure o~osite said deflecting means.
Because o the presence of the deElecting means, recovery of the cooling liquid :is facilitated in its sprial rotating movement and i-ts delivery at the port of the discharge duct. This recovery is efec-ted more rapidly, which further improves the flow of the liquid and allows more efficient cooling of the walls of the enclosure to be achieved.
The discharge duct may extend radially from the center of the enclosure towards the periQhery of the enclosure.
So as not to increase the thickness of the heat exchange device, it is advantageous for the radial dis-charge duct to be inside the enclosure, for it to extend substantially at the same distance from the two lateral walls of the enclosure and for it to be provided with two assemblies of deflecting means sltuated on each side of said duct. Preferably, the radial discharge duct is then shaped outwardly so as to offer minimum resistance to the liquid rotating in the enclosure.
Advantageously, the radial discharge duct opens into a transit chamber, outside the enclosure and compris-ing a water outlet orifice.
Another arrangement, to which recourse is had either in combination with one or other of the preceding ones, or in combination with the improvements of the parent patent, consists in the tangential discharge means comprising a duct opening tangentially into the enclosure, at the periphery thereof, the port of said duct being diametrically opposite the port of the tangential injec-tion means.
In another embodiment of the invention, it is envis-aged that, with the tangential injection means opening into the central part of the enclosure and with the tangential discharge means situated at the periphery of the enclosure, the tangential injection means comprise at least one liquid supply duct opening into at least one face of the enclosure and subs-tantially in the center of said face and at least one assembly of deflecting means situated opposite the port of said duct, so as to impart a tangential force component to the liquid emerging into the enclosure.
The flat cooling boxes used up to now have a general flattened substantially parallepipedic shape whose rear ~ 1 6~

part is nrovided with means for fixing to the plating and whose front part (or nose) is Eormed by a flat face which is fitted with a small radius to the lateral Eaces.
So as to cause the cooling liquid to flow in the nose, there is provided inside the enclosure thus formed at least one separating wall forcing the liquid to follow the outer wall of the box.
However, in the 90 bends, the speed of the streams of liquid-which are situated outermost (i.e. in contact with the wall of the box)- is greatly reduced ; the result is that this bend zone is poorly cooled whereas the nose is precisely the part of the box which is the most exposed to the heat.
Furthermore, this reduction in the speed of the liquid may be such that recirculation, or dead water zone, is created in the bend promoting decantation of solid particles which slow down the heat exchange. The wall of the enclosure heats up, which further increases scaling, which slows down even ~urther the heat exchanges.
This cum~atlve phenomenon spreads by degrees and the box ~inishes by being destroyed under the action of thermo-mechanical abrasion, for poorly cooled copper (from which these boxes are generally made) loses all its mechanical characteristics and is very easily worn, not onl~ by the charges but also by hot gases, dust charqes, etc.
As far as the streams of liquid which are situated innermost in the bend (in contact with the internal ~ 1 6~

separating wall) are concerned, their speed is greatly increased, which may lead to very high speeds of the liquid if the flow has been increased to improve cooling of the plate.
The effects of this high flow rate of the liquid are even more harmful than in the preceding case for, in this region where the liquid undergoes a 180 change of path, there occurs cavitation causing a pressure drop and rapid wear of the separating wall.
lo Furthermore, the increase in the speed of the cooling liquid can only be obtained nractically by reducing the section of the ducts, which leads to a reduction of the volume of liquid and so of the thermal flywheel.
Finally, these boxes are difficult to construct and so costly.
Implementation of the arrangements in accordance with the invention for constructin~ a flat cooling box allows an enclosure to be obtained which comprises no ` bend having a small radius of curvature and in which the streams of liquid follow paths whose radii are suffi-ciently ~reat to avoid creation of the above-mentioned dead zones , furthermore, there exists no nart likely to cause a cavitation phenomenon. Deposits of solid narticles are then avoided and no region of the box is subjected to particular destructive wear.
~oreover, it will 'oe noted that the whole of the cooling liquid mass is set in rotation inside the enclosure and that the whole of this mass participates 1 1 ~51 ~ ~

at all times in cooling the walls. The result is a considerably increased cooling efficiency with respect to what was obtained up to now.
Finally, the manufacture of flat boxes thus construct-ed is very simple and so less espensive than that of knownflat boxes.
In a preferred embodiment, there is provided, for supply and discharge of the cooling liquid, connection means dis~osed side by side and connected to the enclosure by ducts which extend between two planes containing the two substantially parallel faces of the enclosure.
Finally, a complementary arrangement, more particular-ly advantageous in the case where the heat exchange device ls intended to be used as a cooling box, consists in providing a second enclosure covering at least the front part of the first enclosure, no communication for the booling liquid existing betwees~ the first and second enclosures.
The addition of this second enclosure increases considerably the efficiency of the heat exchange device of the invention for a bulk which is in general scarcely greater.
Moreover, by causing the cooling liquid to flow in opposite directions in the two enclosures, better distributed and more even cooling is obtained over the whole of the periphery of the device since there corresponds, to one region of an enclosure through which flows heated liquid, a region of the other 3 3 ~

enclosure through which still cold liquid flows.
The arrangements of the invention find a second application in the so-called "vaporization" oooling boxes in which there is formed vapor bubbles on contact with hot walls.
This type of box is arranged so that the vapor bubbles are collected, by gravity, in the discharge duct for the cooling liquid.
The major disadvantage of the vaporization boxes used at present is that the heat is removed essentially by convection. In the case of harsh heat aggression in a given zone of the box, this heat flow may be all the less efficiently removed since in general no pump is provided in the circuit and since the flow of the cooling liquid takes place naturally by a thermosiphon phenomenon. The result is a calefaction phenomenon in the zone considered, causing in the ducts formation of a vapor plug which interrupts, and may even sometimes reverse, the natural flow of the cooling liquid. Uncooled, the box is rapidly destroyed.
On the contrary, in a cooling box constructed in accordance with the invention, the vapor bubbles are subjected to the action of the contrifugal force due to the rotation of the liquid mass. Thus, because of the existence of this gravitational field, the vapor bubbles are torn from the wall as fast as they are created and are carried towards the center oE the box.
For a cooling box formed in accordance with the ~ ~ 6~1 1 4 preceding arrangement, it is provided for the radial duct, extending from the central zone of the box to the rear thereof, to be situated in the upper part of the box (in - the mounted position thereof), and preferably outside the enclosure, so as to form a chamber for recovering the water-vapor emulsion which is then discharged.
The arrangements of the invention find a third appli-cation in cooling plates.
The cooling plates used at present are in the form of rectangular metal plates through which pass a vlurality of ducts intended for circulation of the cooling liquid.
The ducts are independent of each other and each has an inlet port and an outlet port provided respectively with securing, means for connection to outside hydraulic circuits. Furthermore, these plates comprise securing means for the fixing thereof to the plating of the blast furnace.
Tyr~ically, a known coolinq plate comprises at least twelve securing points, either for fixin~ them or for connecting them to outside circuits.
The very high temperatures to which the plates are exposed cause expansions which are incompatible with such a hi~h number of rigid ~oints and the plates are subjected to mechanical stresses such that they are rapidly made unusable.
Furthermore, the cooling liquid flow rate in these known plates is too low and the thermal fly-wheel thus created is too small to provide efficient coolinq of the plating.
On the contrary, by its very design, the cooling device of the invention, because of the relatively high volume of liquid set in ro-tation, has a high thermal fly-wheel which allows much better cooling than that obtained up to present.
As for the problem of mechanical stresses, it is resolved in the cooling device of the invention by the fact that :
- the two pipes for supplying and discharging the cooling liquid extend approximately perpendicularly to that one of the walls of the device which, in the mounted position in the blast furnace, is in contact with the platinq of said blast furnace, from the central region of said wall, - the two ducts are concentric, at least in the vicinity o:E said wall, - and the means for fixing -the plate tu the ~lating of the furnace comprise that one of said ducts which is outside the other and an orifice, pierced in the plating, adapted to receive said ou-ter duc-t, securing means being used for securing this outer duct to the edge of the orifice or to the zone of the plating surrounding the orifice.
Thus, with these arrangements, the cooling plate is only secured to the ~lating in a single zone, which removes any problem of mechanical stresses due to expansion during operation.

~16~14 ~oreover, still because of the simple structure of the cooling devices in accordance with the invention, cooling plates thus formed are simple to manufacture, so less expensive, than the plates known at present.
A variation of the plate which has just been described consists in providing it with an axial cavity open at both ends, the enclosure surrounding the cavity and the supply and discharge ducts surrounding at least partially the cavity, the transverse dimensions of the cavity being sufficient for it to be possible to introduce therein an elongate and cylindrical cooling device.
It may thus be seen that a combined coollng device, associating a cooling plate and a cooling box, which ensures a particularly favorable result since, for a bulk which is that of the cooling plate, deep cooling is effected within the refractory material, on the one hand, and a thermal screen is Eormed protecting the ~lating, on the other.
Enbodiments of the invention will now be described by way of example. In this descri~tion, reference is made to the accompanying drawings in which :
~ig. 1 shows schematically in section a cooling box in the wall of a blast furnace ;
Fig. 2 is a section along line II-II of Fig. 1 ;
Fig. 3 is a section similar to Fig. 2 of a second cooling box , Figs. 4 and 5 are resectivelv a longitudinal and a cross section of a third cooling box ;

Fig~ 6 is a vertical sectional view of a coolin~
plate ;
FigO 7 is a section along line VII-VII of Fig. 6 and shows also a portion of a blast furnace ;
Fig. 8 represents schematically one embodiment of a heat exchange device constructed in accordance with the invention ;
Fig. 9 is a sectional view along line VIII-VIII of Fig. 8 , Fig. 10 represents schematically another embodiment of a heat exchange device in accordance with the invention;
Fig. 11 shows schematically yet another embodiment of a heat exchange device in accordance with the invention;
Fig. 12 shows schematically yet another embodiment of a heat exchange device in accordance with the invention;
Fig. 13 is a side sectional view of a cooling plate constructed in accordance with the invention ;
Fig. 14 is a sectional view along line XIV-XIV of the cooling plate of Fig. 13 , Fig. 15 shows a further variation of the cooling plate of Figs. 13 and 14 ; and Figs. 16 and 17 show respectively two possible arrangements of cooling plates and boxes in accordance with the invention.
Although it may be used in very different fields, a heat exchanger of the invention finds particularly advantageous applications in the field of iron and steel metallurgy and more particularly in blast furnaces in which it is necessary to cool efficien-tly in particular, on the one hand, the steel plating surrounding on the outside the refractory lining and, on the other hand, the re'fractory lining itself.
Fig.-1 shows a cooling box 1 and the plating 2 of a blast furnace.
As shown in Fig. 1, cooling box 1 is in the form of an elongate tubular element of revolution.
It passes through the plating 2 of the blast furnace through an opening 3 formed therein and is disposed so that its axis of revolution 4 is substantially horizontal.
Over the qreatest part of its length, it is thus surround-ed by the refractory 5, a nose 6, or end of the box turned towards the inside oE the blast furnace and so towards the heat source, being also located in the refractory 5 or on the contrary disengaged, denending on the wear of the refractory 5.
sox 1 is ~ormed from a good heat conducting material and is capable oE withstanding without damage the heat and mechanical stresses ; for this purpose, steel, cast iron or copper or an alloy with a high copper content is used. Furthermore, box 1 is fixed to the plating in an appropriate way, for example by welding with or wi-thout ~acking material depending on the nature of the material used for constructing the box.
Box 1 is formed by a closed jacket 7 which comDrises:
- a cylindrical sidewall 8, as shown in Fig. 1, or slightly in the form of a truncated cone with its conicity ~ 1 B~

directed towards nose 6 (for facilitating the positioning or removal of the box through hole 3 in plating 2) ;
- an outer end wall 9 situated at the end of the box outside plating 2, this wall being flat ; and - an inner end wall 10 situated at the nose end of box 1 which may be flat (as shown in Fig. 1) or bulging.
This jacket 7 defines a closed enclosure 11 in which a cooling liquid is set in motion as will be described further on.
The inner surface 12 of sidewall 8 presents no roughness and is substantially smooth so as to create no turbulence in the liquid in motion.
In box 1 there is provided an orifice 13 Eor inject-ing cooling liquid and an orifice 1~ for discharging this liquid, these two orifices being located respectively at the two axially oDposed ends of the box.
As nose 6 oE box 1 forms the part thereof situated the closest to the heat source, it is very desirable that the cooling liquid be injected at this point. For this purpose, an inlet pipe 15 is provided which sealing-ly passes through the outer wall 9 of box 1 and whose orifice 13 is located immediately proximate the inner surface of the inner wall 10. For a purpose which will become clear later, ~ipe 15 is straight and its axis merges with the axis of revolution of jacket 7.
~ith this arrangement discharge port 14 is situated adjacen-t the outer end wall 9.
So as to be sure that the cooling liquid licks ~ ~S~l~

continuously the inner surfaces of the walls of jacket 7, more particularly surface 12 of sidewall 8, it is provided that the mass of cooling liquid be actuated with a rota-tional movement about the axis of revolution 4 of jacket 7.
So as no-t to complicate the manufacture and the maintenance of the device, this setting in rotation of the liquid mass is obtained in a simple way by injecting the liquid through port 13 wi.th a tangential speed component.
In this connection, it should be noted that nose 6 is the part of the cooling box whixh is the most exposed to the heat ; it is then through nose 6 that maximum cooling must be effected. It is then important for the cooling liqui.d leaving port 13 not only to strike (arrows 60 of Fig. 1) the inner wall 10 of nose 6, in the central region thereof, ~ipe 15 being axial, but also, from this moment on, to be deflected with a rotational speed compon-ent tarrows 61 and 64 in Figs. 1 and 2) so that it ~athes the whole of the inner wall 10 of nose 6 : thereby, the whole of nose 6 of box 1 partici ates in the cooling.
In addition, the cooling liquid must be brought back to the outer wall 9 and dischar~e ~ort 14 while effecting a helical mGvement (arrows 62 in Fig. 1) along the inner surface 12 of sidewall 8. Thus, the liquid in motion must present two speed com~onents :
- an axial component (arrow 63 in Fig. 1) directed towards the outer end wall 9 and intended to cause the liquid to return to the outer end of the box~

1 :1 6~ 4 - and a rotational componerlt (arrows 61 and 64 in Fi~. 2) intended to make the liquid turn along wall 8 so as to cool this latter.
of course, the above explanation of the beakdown of the movements executed by the mass of liquid leaving port 13 is theoretical and, in practice, these movements are intercombined (arrows 62 in ~ig. 1). To this end, it is provided that the inner surface 16 of the inner end wall 10 is formed to have hollows or projections 17 constituting blades in the form of s~iral sections dispos-ed all around port 13 and acting as deflectors for the liquid ~rojected by port 13 situated axially opposite, so as to communicate thereto a rotational component.
Thus, from injection port 13, the stream of liquid strikes the inner face of nose 6 and, from this moment on, is deflected by the inner end wall 10 at the same time as it is rotationnaly deflected by blades 17 (arrows 61 and 64).
So that the rotational movement of the liquid mass takes place evenly and without turbulence, it is further-more desirable for the discharge of the liquid through port 14, at the opposite end of box 1, to take place tangentially and for a discharge ~ipe 18 to be suitable dis~osed in relation to wall 8 of jacket 7. Due to the fact that the inner surface 12 of wall 8 of jacket 7 is smooth and that the inlet ~i~e 15 is coaxial to the axis of revolution 4 of jacket 7, it is certain that, under the action of the tangential speed component of the 1 ~ 6Sl 1 ~

liquid injected through port 13, the mass of liquid is propelled with an undisturbed rotational movement and that the liquid flows smoothly from the inner end wall 10 towards the outer part of the box while continuously licking the wall 8 o~ jacket 7.
In the cooling box 65 of Fig. 3, an inlet pipe 66 bringing cooling liquid has a diameter a little greater than that of pipe l5 of the box of Figs. 1 and 2.
In box 65, the deflector means are formed by two projecting walls, respectively 67 and 68, forming respect-ively arcs of two spirals wound one in the other. Similar-ly, in the preceding examnle, these two projecting walls are carried by an internal face of a nose of the cooling box 65.
As shown in Fig. 3, wall 67 comprises a central part 69, i.e. located in a zone of low radius of curvature of the spiral, disposed across a supply port 70 of the inlet pipe 66 , this central part 69 presents two regions, of substantially equivalent lengths, having opposite curva-tures, i.e. the central part 69 has the general shape of an S.
Beyond the central part 69 (towards the left in Fig.
3), the projecting wall 67 develops along a spiral, with a continuously increasing radius of curvature, substan-tially over a complete turn. At this point, it joinsagain at 71 a side wall 72 of the box 65.
As for the other projecting wall 68, it is initiated substantially on the radius joining the axis o~ revolution ~ ~ ~5 1 ~ ~

of the box 65 to zone 71 along the side wall 72 of the box 65, and cancels out disturbances sustained by streams of liquid at the point of their change of guiding surface, i.e. from the internal face of the nose of the box 65 to the in-ternal face of the side wall 72.
When the cooling liquid leaves the supply port 70 of the inlet pipe 66, it is divided into two streams by the S-shaped region 69. A first part of the liquid is rotated following arrow 74 and flows along the wall 67, then between the wall 68 and the o~lter wall 72 of the box 65. A second part of the liquid is rotated following arrow 75 and flows first between the walls 67 and 68, then between the walls 67 and 72.
Because of the lengths of the walls 67 and 68 are appreciably greater than those of blades 17 of the coolinq box of Figs~ 1 and 2, t:he liquid can be more evently set in rotation, the liquid being guided for a longer period of time.
In order to improve the effect obtained, S-shaped region 69 of wall 67 can be made to penetrate a little inside tne inlet pipe 66, thus the liquid is di~7ided into two streams and its rotation may be initiated a little before it leaves through the supply port 70.
Of course, the deflector means may just as well be carried by the end of the inlet pipe 66 which is situa-ted around the supply port 70.
Furthermore, so as to extend the guiding of the streams of liquid, the walls 67 and 68 may be extended ~ ~ 6 ~

for a short distance.
Figs. 4 and 5 show a coolinq box 80 in which a part of the deflector means is carried by the end of a liquid inle~ pipe 82 (creating a primary rotation) whereas another part of the deflector means is carried by an internal face 86 of a nose 87 of the cooling box 80 (and completes the setting of the liquid in rotation).
As shown in Figs. 4 and 5, the cooling box 80, which may be formed as a whole like the box 1 of Fig. 1 is provided with an annular jacket 81 surrounding the liquid inlet ~ipe 82, and defining with an outer wall 83 of the box 80 an annular chamber 84 in which the cooling liquid is intended to flow helically in the Eorm of a relatively thin layer and at high speed.
Towards its outlet 82a, the liquid inlet pipe 82 is provided with a deflector 85 partially engaged in the pipe 82 and disposed end to end with the internal face 86 of the nose 87 of the box 80.
A deflecting member 85, in cross-section, is in the form of a four-legged cross-piece, each leg 88 being axially curved so as to form a deflecting trough 89.
Deflecting member 85 is an insert in the end of pipe 82.
Moreover, the internal face 86 of nose 87 of box 80 is not flat, but is substantially in the shape of a truncated cone with a central ~art in the shape of a spherical skull-cap, the whole forming a prominence directed inwardly of box 80. Furthermore, this internal ~ 3 B~

face 86 carries deflecting walls 90, 91, 92, 93 in the shape of arcs of a spiral, projecting parallel to the axis of revolution of the enclosure.
The first wall 90 is situated opposite one of the deflecting troughs 89 of deflecting member 85 and develops, with a curvature identical at the start to that of the trough, along an arc of a s~iral for approximately a complete turn, the radius of curvature increasing conti-nuously.
The second wall 91 starts substantially at the free end of the first wall 90, while being located inwardly of the spiral described by wall 90 at a distance e thereErom.
Furthermore, walls 90 and 91 face each other over a curvilinear length 1. ~all 91 clevelops in its turn along an arc of a spiral approximately over a quarter of a turn.
The third wall 92, beginni.ng at a distance e from wall 91 and situated opposite t:hereto over a length 1, develc~ps along an ars of a spiral approximately for a quarter of a turn~
Finally, the fourth wall 93, situated at distance e from wall 92 and also from wall 90, extends over an arc of a spiral for approximately a quarter of a turn parallel to wall 90.
In addition, as can be best seen in Fig. 4, the free edges of the deflecting walls 90 to 93 are coplanar and the front end of annular jacket 81, which is also flat, is disposed end to end against the free edges of deflect-ing walls 90 to 93. Thus, there is defined an assembly of spiral passages of variable and increasing widths (taken in the directlon of flow of the liquid) intercommu-nicating through necks of lengths 1 and widths e.
With this arrangement, the cooling liquid brought by pipe 82 begins to be set in rotation by the deflecting member 85 with troughs 89 before it leaves through outlet 82a of pipe 82. At thls moment, the rotational movement continues to be communicated to the liquid by deflecting walls 90 to 93.
Because of the relative positions of walls 90 to 93, the liquid is caused to pass through a neck of width e, irrespective of the ~ath followed. Because of the rela-tive narrowness of these necks, the liquid is accelerated during its passage therethrough, which ensures that the cooling liquid will begin to follow a helical path, in annular chamber 8~, with a rotational speed component sufficien-tly high for it to reach the o-ther end of the cooling box at a tangential speed which allows discharge thereof by simple inertia. Experiments have shown that, in order to obtain this result, it is advisable for the rotational component to be about ten times greater than the axial component directed towards the outer end of box 80.
By way of modification, a one ~iece independent part may be formed obtained for example by moulding, compris-ing deflecting member 85 and deflecting walls 90 to 93, this independent part being fitted into the end of pipe 82 and disposed end to end against the internal face 86 of nose 87 of coollng box 80.
The deflecting member 85 may also be formed by moulding to form a single piece with nose 87 of coollng box 18 and wlth deflectlng walls 90 to 93; under these conditions, member 85 flts lnto the end of pipe 82 when this latter is positioned in box 80 and contrlbutes to facllitatlng this posltlonlng.
Referring to Figs. 6 and 7, there will now be des-cribed another embodlment of the invention.
Here a cooling box has a flattened shape and in the art is called a "cooling plate". This terminology will be adopted in the continuation of the description.
Such plates are not disposed in the refractory like the elongate boxes previously described but between the refractory and the internal face of the plating so as to form a continuous or discontinuous thermal screen, depending on the gap left between two consecutive plates, between the heat source and the plating.
These plates are, like the elongate boxes, made from a heat conducting and mechanlcally resistant material, such as steel, cast iron or co~per.
Referring to Figs. 6 and 7 in which is shown a plate 20, this plate 20 has a flattened shae, its parallel faces 21 and 22 being respectively in contact wlth ~lating 23 and the refractory 24 of a blast furnace, and it ls hollow to allow cooling to flow.
Faces 21 and 22 are round. An injec-tlon port 25 opens into plate 20 tangentially to a substantlally cylindrical sidewall 26.
A discharge port 27 ooens tangentially adjacent the center of plate 20 and a discharge pipe 28 coils towards the center of the plate and is bent so as to leave the plate through the face 21 in the center thereof. Liquid inlet 25a and dischar~e 27a pi~es are disposed substan-tially perpendicularly to the plate.
Plate 20 has the general aspect of a snail shell.
It will be noted that the axes of the injection 25 lo and discharge 27 ports are respectively at distances R
and r from the center C of box 20. For this reason, so that the inlet and outlet flows of liquid may be equal, it is necessary for section S of the dischar~e oort to be ~reater than section 5 of the in~ection port.
The equality of flows produces as a consequence :
Vl S = V2 . S

V1 and V2 designating the inlet and outlet speeds which are in the ratio of distances R and r, i.e. :

=
R r The following geometrical condition must then be achieved :
R _ S
r s Similarlv, as in the case of the elongate box 1 of Fig. 1, it is necessary for the internal walls of olate 20 to oresent no roughness so as not to create turbulence ~ ~6~14 within the mass of liquid in motion.
During operation, because of the tangential injection of liquid through port 25, the liquid mass is propelled with a rotational movement and evenly licks each point of S walls 21, 22 of plate 20. It can be considered that the stream of liquid, introduced through port 25, coils round within the inner volume of the plate before reaching discharge port 27.
With the setting in rotation of the mass of cooling liquid, with the help of suitable deflector means, and by disposing the injection and discharge ports for the liquid in o~posite regions of the device, it is ensured that each zone of walls 21, 22 to be cooled is licked by the li~uid and is thus efficiently cooled.
By arranging for walls 21, 22 not to have any rough-ness and for nothing to opose the rotational motion of the liquid mass, this latter is the seat of no turbulence and all the zones of walls 21, 22 to be cooled whichever they are and wherever they are located, are cooled in the same manner and with the same efficiency. Furthermore, pressure losses in a hydraulic circuit supplyin~ plate 20 are practically eliminated.
lt is thus ~ossible to calculate very accurately the minimum flow of liquid to be injected into plate 20 so as to obtain a predetermined cooling and so as th achieve substantial economies on the amount of liquid necessary and, conse~uently, on the cost price of the cooling.
The flow of the liquid can also be accurately calcul-~ ~6~1~4 ated so that it heats up to a high tem~erature, this heating up going ~ossibly far enough to cause vaporization, which allows the efficiency of the device to be further increased due to the fact that the vapors, while escaping, help in the movement of the remaining liquid mass.
The geometrical shaes of the component parts of ~late 20 are simplified. This reduces the amounts of mate-rial necessary and the manufacturing cos-ts and so the overall cost price of the device. Thus, manufacturing of plate 20 from steel, cast iron or cop~er may be considered.
It is possible to mount several plates 20 or boxes 1, 65, 80 in series by intercoupling them ; thus there can be provided for exam~le several intercoupled elongate cooling boxes, coupling between a cooling box and a cooling plate or intercoupling between several cooling plates.
DifEerent particular embodiments of heat exchange devices of the flat type appropriate for certain particular applications will now be described.
Referring first of all to Figs. ~ and 9 concerning a first embodiment, cooling box 60 comprises an enclosure 61 cylindrical in revolution having a flattened shape, i.e. its height is small in relation to its diameter.
A duct 62 for supplying cooling liquid opens tangen-tially into enclosure 61.
For discharging the li~uid there is provided, on the one hand, an outlet 63, substantially diametrically oppo-site the ~ort of suDply pi~e 2 and, on the other hand, a ~ :1 6 ~

channel 63 extending radially a-proximately from the center to the periphery of enclosure 61 ; channel 63 is situated at the same distance from flat walls 64 of the enclosure and lt is flattened and shaped, as can be seen S at 65 in Fig. 9, so as to only disturb the liquid flow to a lesser degree.
Two holes 66, pierced respectively in the lateral faces thereof and contered at the center of the enclosure, allow the cooling liquid to pass from the enclosure into channel 63.
To facilitate this passage, there is furthermore provided, on each side of channels 63 (i.e. between each face 67 of the channel and each wall 64 oE the enclosure), a deflecting device 68 formed from blades wound in the direction of the center of holes 66.
Channel 63 extends towards the rear of cooling plate 60, i.e. opposite the zone (or nose) 69 intended to be directed towards the reg`ion of the blast furnace to be cooled when the box is installed in its operating posi-tion.
Channel 63 opens into a discharge chamber 70, conti-guous with enclosure 61 and situated therebehind.
A duct 71 for discharging the cooling liquid opens into chamber 70, preferably op~osite the port through which channel 63 opens into chamber 70 or opposite port 63a.
The cooling liquid (in general water), supplied by duct 62 (arrow 72) arrives in enclosure 61 in which, ~ J6St~4 considering the form thereof, there is created a spiral movement (arrow 73). A ~art of the liquid of -the external stream, which is in fact the most heated in contact with the wall of nose 69, passes directly through port 63a (arrow 73a) to be discharged. The rest of the mass of water, once in the vicinity of the central region of the enclosure, is recovered by the deflecting devices 68 (arrow 74) and penetrates into channel 63 from where.it passes into chamber 70 (arrow 75) then leaves through duct 71 (arrow 76).
It will be noted that the whole of cooling box 60 is comprised between two ~arallel planes containing the faces 74 of the enclosure. The result is that box 60 may be easily introduced through the plating of -the blast furnace into its housinrJ provided in the refractory material. Conversely, it may be easily removed therefrom, for exam~le with a view to its replacement.
Fig. 10 (in which the elements identical to those in Figs. 8 and 9 are designated by the same reference number) shows a so-called "vaporization" cooling box 77 whose construction corresnonds in a general way to that of box 60 of Figs. 8 and 9, with the excention of channel 63 which is transferred to the outside of the enclosure.
More precisely, there is associated with one of the walls of the enclosure (in the present case the one 78 which is disposed at the to~ in the mounted ~osition of the box on the plating of the blast furnace, such as shown in Fig. 3), an elongate shell 79 defining with wall 78 an outer channel 80.
A supply duct 62 opens tangentially into enclosure 61, for example in accordance with the configuration of Fig. 1 or in accordance with any other configuration, whereas a discharge duct 71 leaves from channel 80. Just as in the preceding embodiment, vanes 68 are provided for causing the liquid to pass through a hole 66 communi-cating enclosure 61 with channel 80.
Another hole 81 is provided for connecting discharge chamber 70 with channel 80.
During operation, the vapor bubbles which form particularly in contact with the wall of nose 69, the most exposed to the heat, are torn away as fast as they are created and carried by the rotating liquid mass into enclosure 61.
Considering the gravitational field which reigns within the liquid mass, the vapor bubbles are brought to the center of enclosure 61 where they pass into channel 80. Since the liquid is in continuous circulation within the enclosure, there cannot be formed, alont the internal face of the walls, particularly in the nose, a vapor veil preventing heat exchanges neither a vapor plug stopping circulation of the water.
The cooling box 83 shown in Fig. 11 is designed, contrary to the proceding ones, with a central inlet and a tangential discharge.
A supply duct 84 opens into the center of an enclo-sure 85 cylindrical in revolution, the liquid penetrating perpendicularly to the circular face 86 of the enclosure.

~ 3 16$1 ~ ~

Deflecting means 87, formed for example like those 68 of Figs. 8 to 11, impart to the liquid a tangential compo-nent so that it is set in rotation and describes a spiral path from the inside to the outside of the enclosure (arrow 88).
A discharge duct 89 extends tangentially and recovers the heated liquid.
Fig. 12 shows yet another embodiment of a cooling box in accordance with the invention. Box 90 of Fig. 12 is designed from plate 60 of Figs. 8 and 9 all the elements of which it employs (the same reference numbers have been kept in Fig. 12).
There ist however added a second enclosure 91 which is simply formed by a tubular duct bent in a semi-circle so as to assume the rounded shape of nose 69 of plate 60 of Fig. ~. Tubular duct 91 is connected to the outside hydraulic network by means of supply 92 and discharge 93 ducts.
It will be noted that, in enclosure 61 and in duct 91, the flow directions for the liquid are opposite (respecti-vely arrows 94 and 95).
The result is that in the vicinity of discharge duct93, where the liquid already heated by its travel through duct 91 is less efficient, beneficial cooling is provided by the cold liquid arriving through duct 62 and emerging into enclosure 61. And conversely in the region of ducts 71 and 92. It is thus possible to obtain better distribu-tion of the cooling of the refractory and, in a general ~ 3~114 way, improved eficiency.
It will be noted that in Fig. 12, cooling box 91 has been shown in an operational position, i.e. as has already been explained morever above, the plate extends practi-cally perpendicularly to the plating 96 of the blastfurnace to which it is fixed in an appropriate way by means of an intermedia-te shoe 97 and it penetrates into the refractory 98, its nose 99 being -turned towards the hot re~ions of the blast furnace.
Figs. 13 and 14 show a cooling plate lOOr for insert-ing (as has already been indicated above) between the plating 101 of a blast furnace and the refractory wall (not shown).
Cooling plate 100 has an enclosure 102 cylindrical in revolution, a supply duct 103 for the cooling liquid and a discharge duct 104 for this liquid.
The two ducts 103 and 104 ex-tend, at least in a zone adjacent the coolinq plate, substantially perpendicularly to that one 105 of the walls of the enclosure which is turned towards plating 101. Furthermore, the two ducts 103 and 104 are coaxial, duct 104 bein~ inside duct 103, which surrounds it.
By way of example, the arrangement for the cooling plate may be the following.
Supply duct 103 communicates with a channel 106, provided on the outer face of said wall 105 of the enclosure, which opens into enclosure 102 at the peri-phery thereof through a port 107. A deflecting wall 108 J 1 ~

is provided in front of port 107 to deflec-t the liquid flow so that it gushes tangentially into the enclosure.
Diametrically opposite port 107 is an outlet port 109 by means of which enclosure 102 commu'hicates with a channel 110 (also situated outside wall 105 for example) ending in a central chamber lll of the enclosure. This central chamber communicates with the rest of the enclo-sure through apertures 112. In chamber 111 are also disposed deflecting vanes 112 situated opposite the port through which discharge duct 104 opens into said chamber 111 .
For fixing cooling plate 100 in the blast furnace, a hole 1l3 wlth a diameter corresponding substantially to the outer diameter of supply duct 103 is bored in plating 101 ; duct 103 introduced into hole 113 is welded to the plating. Cooling plate 100 is thus securely fixed to the plating solely by its central region, represented by duct 103 serving as a fixing sleeve.
Whatever the deformations which the cooling plate may undergo through the action of the heat, i-t will be able to freely expand without it being the seat of des-tructive stresses as was the case with the prior cooling plates presenting a plurality of fixing zones.
Of course, it will be understood that the arrangements which have just been described and combining the supply and discharge means for the cooling liquid with the fixing means are not dependent on the particular configuration of -the enclosure shown in Figs. 13 and 14, and which has ~ ~S~4 only been given by way of example, and that they may just as readily be associated with other enclosure configuration, such as those previously described.
Fig. 16 shows an arrangement combining cooling plates 100, such as those which have jus~ been described, disposed in a staggered arrangement and cooling boxes lOOa disposed in the free sectors between the ~lates.
Thus deep coollng of the refractory, provided by the boxes, may be combined with surface cooling, intended to lC protect the plating, created by the plates~
Fig. 15 shows a cooling plate 114 which is a variation of the cooling plate 100 of E`igs. 13 and 14.
Plate 114 comprises an axial annular chamb2r 115 surrounding an axial cylindrical cavity 116 open at both its ends.
~nnular chamber 115 is subdivided into two semi-cylindrical half ehambers 117 and 118 in whieh emerge respeetively the supply 119 and diseharge 120 duets for the eooling liquid.
For the rest, the eooling plate may be arranged in a substantially identical way to plate 100 of Figs. 13 and 14 or be construeted in aceordanee with one or other of the preceding examples.
Plate 114 as a whole is formed so that the axial cavity 116 has a sufficient transverse dimension for a cooling box 121 (preferably, but not exelusively, a cooling box constructed in accordance with the arrangements described in the parent patent).

` ` 116511~

It is thus possible to form cooling plate + box assemblies which provide, in the same zone of the blast furnace, cooling of the reEractory wall (deep cooling) and cooling between the plating and the refractory wall (surface cooling or thermal screen effect).
Fig. 17 shows the combination of such cooling assem-blies (plate 114 + box 121) disposed in a sta~gered arrangement with cooling boxes 122 alone (which may also be preferably, but not exclusively, of the type described in the parent patent) disposed in the sectors left free (arrangement at the corners of a hexagon circumscribed on plates 114).
It is thus possible to create veritable thermal barriers, whose action extends not only in depth in the refractory but on the surface and which, through the arrangement oE the cooling boxes, provides good anchorage for the refractory.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A heat exchanger comprising a body shaped substan-tially as a body of revolution and having first and second end walls and a curved wall extending therebetween, the first end wall and tue curved wall being heat-transfer walls and at least the curved wall having a substantially smooth inner surface, a heat-transfer fluid supply port adjacent to the first end wall and adapted for tangentially supplying heat transfer fluid into the body, a heat-trans-fer fluid discharge port adjacent to the periphery of the second end wall and adapted for tangentially discharging the heat transfer fluid from the body, whereby in use, tangentially supplied heat transfer fluid flows from the supply port outwardly and with a rotational motion about the axis of the body over the inner surface of the first end wall and thence, with a free helical motion around the axis of the body, over the inner surface of the curved wall to the discharge port.

2. A heat exchanger according to claim 1, in which deflecting members are provided for deflecting the heat transfer fluid supplied by the supply port to flow outwardly and with the said rotational motion.

3. A heat exchanger according to claim 2, in which a heat-transfer fluid supply pipe extends axially through the interior of the body to the supply port which is adjacent to the center of the first end wall.

4. A heat exchanger according to claim 3, in which the fluid-deflecting members extend into the fluid-supply pipe.

5. A heat exchanger according to any of claims 2 to 4, in which the fluid-deflecting members comprise curved vanes on the inner surface of the first end wall.

6. A heat exchanger according to claim 5, in which at least a portion of the vanes is formed as a member attached to the fluid supply pipe.

7. A heat exchanger according to claim 2, in which the deflecting members impart to the fluid a rotational speed component which is approximately ten times a speed component directed axially towards the second end wall.

8. A heat exchanger according to claim 1, in which the first end wall has a central, inwardly-domed portion.

9. A heat exchanger according to claim 3, having an internal sleeve extending coaxially with the fluid-supply pipe from the second end wall to an internal wall, the internal wall being adjacent to the first end wall and extending between the sleeve and the end of the pipe which is adjacent to the first end wall, the sleeve defining an annular space for the helical flow of liquid between itself and tue curved wall.

10. A heat exchanger substantially as hereinbefore described with reference to any of Figs. 1 to 5 of the accompanying drawings.

11. A heat exchanger comprising a body shaped sub-stantially as a body of revolution and having first and second end walls and a curved wall extending therebetween, he first end wall being a heat-transfer wall, a supply port and a discharge port for heat-transfer fluid, the ports being spaced-apart radially, the supply port being adapted for tangentially supplying the heat-transfer fluid into the body and the discharge port being adapted for tangentially discharging the heat-transfer fluid from the body, so that, in use, the fluid flows between the parts in a spiral path over the inner surface of the first end wall, the body having no internal obstacle to such flow.

12. A heat exchanger according to claim 11, in which one port opens tangentially into the body adjacent the curved wall, the other port is adjacent the center of the first end wall, and a deflecting member is provided adjacent the supply port for deflecting the fluid to flow tangentially into the body.

13. A heat exchanger according to claim 12, in which said fluid deflecting member is a curved vane.

14. A heat exchanger according to claim 11 , in which the supply port and the discharge port are respectively adjacent the periphery and the center of the first end wall.

15. A heat exchanger according to claim 11 , in which both ports are spaced from the axis of the body and the ratio of the areas of the ports is the inverse of the ratio of their radial distances from the axis.

16. A heat exchanger in accordance with claim 11, in which the means for tangential injection of the liquid opening tangentially into the enclosure at the periphery or in the vicinity of the periphery thereof and the means for the tangential discharge of the liquid being situated at the center of the enclosure, the tangential discharge means comprise at least one assembly of deflecting means situated in the center of the enclosure and a duct opening into a face of the enclosure opposite said deflecting means.

17. A heat exchanger according to claim 16, in which the discharge duct extends radially from the center of the enclosure to the periphery of the enclosure.

18. A heat exchanger according to claim 17, in which the radial discharge duct is inside the enclosure and extends substantially at the same distance from two lateral walls of the enclosure and wherein there are provided two assemblies of deflecting means, these two assemblies being situated on each side of said duct.

19. A heat exchanger according to claim 18, in which the radial discharge duct is shaped outwardly so as to offer minimum resistance to the rotating liquid in the enclosure.

20. A heat exchanger according to claim 17 , in which the radial discharge duct opens into a transit chamber, outside the enclosure and comprising a water outlet port.

21. A heat exchanger according to claim 17, in which the radial duct is situated in tue upper part of the enclosure and preferably outwardly thereof.

22. A heat exchanger according to claim 16 or according to claim 11, in which the tangential discharge means comprise a duct opening tangentially into the enclosure, at the periphery thereof, the port of said duct being diametrically opposite the port of the tangential injection means.

23. A heat exchanger according to claim 11, in which the tangential injection means opening into the central part of the enclosure and the tangential discharge means being situated at the periphery of the enclosure, the tangential injection means comprise at least one supply duct for the liquid opening into at least one face of the enclosure and substantially in the center of said face and at least one assembly of deflecting means situated opposite the port of said duct, so as to impart a tangen-tial component of force on the liquid emerging into the enclosure.

24. A heat exchanger according to claim 16 , in which, for the supply and discharge of the liquid, it comprises connection means situated side by side and connected to the enclosure through ducts which extend between the two planes containing the two sub-stantially parallel faces of the enclosure, whereby the heat exchanger is able to be mounted on the wall of the blast furnace perpendicularly thereto, in the manner of a cooling box.

25. A heat exchanger according to claim 16 , in which there is further provided a second enclosure covering at least the front part of the first enclosure and wherein there exists no communication for the cooling liquid between the first and second enclosure.

26. A cooling device according to claim 16 , the injection and discharge means comprising respectively a liquid supply duct and a liquid discharge duct, in which the two ducts extend approximately perpen-dicularly to one of the walls of the enclosure, at least in the vicinity of said wall, substantially from the central zone of said wall, wherein the two ducts are concentric at least in the vicinity of said wall, and wherein means for securing the device to the plating of the blast furnace are provided which comprise, on the one hand, that one of said ducts which is outside the other and, on the other hand, an orifice provided in the plating and adapted to receive said outer duct, securing means being used to secure the outer duct to the edge of the orifice or to a zone of the plating surrounding the orifice.

27. A cooling device according to claim 16 , in which there is provided an axial cavity open at both ends, the enclosure surrounding the cavity and the supply and discharge ducts surrounding at least partially the cavity, the transverse dimensions of the cavity being sufficient for it to be possible to introduce therein an elongate and cylindrical cooling device.

28. A heat exchanger substantially as hereinbefore described with reference to Figs. 6 to 17 of the accompanying drawings.