US 3612501 A
Description (OCR text may contain errors)
United States Patent Inventors Frank A. Berczynski Williamsville; Herbert L. Benz, Orchard Park, both of N.Y.
Appl. No. 861,742
Filed Sept. 29, 1969 Patented Oct. 12, 1971 Assignee A. E. Anderson Construction Corporation Buffalo, N.Y.
FURNACE-COOLING APPARATUS 9 Claims, 4 Drawing Figs.
US. Cl 263/44, 266/32 F27b 1/24 263/44; 266/32  References Cited UNITED STATES PATENTS 1,030,792 6/1912 Roberts 266/32 2,711,311 6/1955 Affleck et a1. 266/32 2,824,731 2/1958 Schwengel 266/32 Primary Examiner-John J.. Camby A t t0rneyChristel & Bean ABSTRACT: An annular liquid-distributing chamber encircles the exterior shell of a furnace and has an open space in the bottom wall thereof extending the entire length of the chamber. A resilient sealing strip attached to the chamber bottom wall extends across the open space into contact with the exterior shell so as to distribute cooling liquid therealong. One or more conduits deliver cooling liquid to the chamber behind a weir over which liquid flows to the sealing strip. A trough spaced below the chamber receives cooling liquid after it has traveled downwardly along the shell surface.
FURNACE-COOLING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to cooling of the exterior shell of a furnace and, more particularly, to furnace-cooling apparatus of the type which causes a sheet or film of cooling liquid to flow along the outer surfaces of the furnace shell.
One area of use of the present invention is in the cooling of the exterior shell of ablast furnace although the principles of the invention'can be variously applied to cooling of other types of furnaces. A method commonly employed heretofore consists of spraying water onto the furnace exterior shell, butthis method is unsatisfactory in several respects. The fine mist formed in connection with the water spray can be carried by air currents to surrounding surfaces and structures rendering the surfaces slippery and hazardous and accelerating corrosion or deterioration of the structures. With particular reference to blast furnaces, spray cooling is unacceptable for certain areas of the furnace due to the possibility of water accumulation in areas where iron and slag are being handled. By its very nature a spray results in uneven cooling which in many applications is unsatisfactory. In addition, spray cooling is undesirable when the region surrounding the furnace is exposed to winter temperatures because settling water results in ice formation and an obvious safety hazard to operating personnel.
An alternative cooling arrangement has been proposed wherein a sheet or film of cooling liquid, often water, is caused to flow along the outer surface of the furnace shell. This arrangement presents several design requirements which must be met if the surface is to be cooled evenly. One is control of the velocity of the liquid film so as to prevent any disturbance in the continuity of the film, which otherwise would cause uneven cooling, and to prevent the film from being deflected from its path by irregularities in the furnace shell surface. Another requirement is that the cooling liquid be introduced to the furnace shell continuously around the circumference thereof which is complicated by the fact that liquid usually is supplied at discrete points by individual, circumferentially spaced conduits.
Arrangements of this general type heretofore available have been limited to cooling of vertical surfaces or surfaces directed downwardly and outwardly. This is because prior arrangements have included an opening in the distributing reservoir encircling the shell and the surface tension of the liquid causes it to cling to edge of the opening and flow outwardly along the reservoir undersurface and away from the surface to be cooled.
SUMMARY OF THE INVENTION It is therefore, an object of the present invention to provide apparatus for cooling the exterior shell of a furnace of the type whereby a continuous film of cooling liquid is caused to flow along the outer surface of the furnace shell regardless of the direction of inclination of the shell outer surface.
It is a further object of this invention to provide such cooling apparatus in which a circumferentially continuous film of cooling liquid is obtained from a plurality of discrete inlet or supply points.
It is further object of this invention to provide such cooling apparatus which is simple in construction and convenient and economical to manufacture and maintain.
The present invention provides apparatus for cooling the exterior shell of a furnace including a continuous annular distributing chamber encircling the shell to which chamber cooling liquid is supplied at discrete locations. A sealing strip of resilient material extends from the chamber into contact with the shell. A weir in the chamber provides a circumferentially continuous flow of liquid at a reduced velocity onto the sealing strip which flexes in response to the force of the liquid whereby a thin film of liquid is caused to flow onto and along the outer surface of the furnace shell.
The foregoing and additional advantages and characterizing features of the present invention will become clearly apparent upon a reading of the ensuing detailed description of an illus trated embodiment thereof together with the included drawing depicting the same.
BRIEF DESCRIPTION OF THE DRAWING FIGURES FIG. I is a fragmentary vertical section view of a furnace provided with cooling apparatus of the present invention;
FIG. 2 is a fragmentary plan view thereof taken about on line 22 in FIG. 1;
FIG. 3 is an enlarged view of a portion of the cooling apparatus, taken about on line 3-3 in FIG. 2; and
FIG. 4 is a fragmentary elevational view thereof taken abut on line 44 in FIG. 3.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT FIGS. 1-4 show a preferred form of cooling apparatus provided by the present invention as it would appear in use for cooling the exterior shell of a blast furnace 10. It should be understood that blast furnace 10 is merely illustrative of one of the many types of furnaces in which the cooling apparatus of the present invention can be employed. Blast furnace 10 includes, briefly, a hearth area 11, a bosh area 12 and stack area 13. A lining of refractory material 14 surrounds the furnace hearth and bosh areas 11, I2 and the lower portion of the stack area 13 shown in FIG. 1. Refractory lining I4 is surrounded by an exterior shell 15 which is cooled by .the apparatus of the present invention. In this illustrative blast furnace I0, shell 15 is of steel and includes a hearth jacket portion l5a, a tuyere jacket portion [5b, a bosh jacket portion l5c and a stack shell portion l5d. A mantle 16 and mantle flange 17 are included between the bosh jacket I50 and stack shell l5d.
In accordance with the present invention, furnace exterior shell 15 is cooled by apparatus which causes a thin film of cooling liquid, in many instances water, to flow along the outer surface of the shell. The present illustrative example includes two similar arrangements of apparatus for cooling the bosh jacket I50 and hearth jacket 15a portions of shell 15 although it will be appreciated that additional arrangements or in some instances a single arrangement can be employed, the number and vertical location thereof depending upon the size and shape of the particular furnace to be cooled.
Referring now to FIG. 1, the cooling apparatus of the present invention includes means for distributing cooling liquid over the exterior of the furnace shell in the form of chamber 20. Chamber 20 in preferred form is annular and continuous, completely encircling furnace shell 15, in particular bosh jacket portion 150, and includes a generally horizontal bottom wall 21 and a generally vertical sidewall 22 extending upwardly from bottom wall 2l. The top edge of sidewall 22 can be joined in a suitable manner to the bottom surface of a generally horizontal member 23 which serves to enclose or cover the top of chamber 20. Member 23 conveniently can be a horizontal extension of furnace shell portion l5c or a separate ring member joined to shell portion 15c and to mantle flange 17. Chamber bottom wall 21 and sidewall 22 each can comprise, for convenient assembly and structural rigidity, a plurality of sections joined to each other and supported from shell 15 at spaced locations.
A conduit designated 25 in FIG. 1 extends through sidewall 22 for the purpose of supplying liquid coolant, for example, water, to the interior of chamber 20. While a single inlet conduit is shown in FIG. 1, it is to be understood that a plurality of similar conduits can be provided through sidewall 22 at spaced locations around the circumference thereof. Each conduit 25, in turn, is connected at the other end to a source of cooling liquid (not shown).
Chamber 20 has a liquid discharge portion adjacent the furnace shell, and in this particular example bottom wall 21 terminates a short distance from furnace shell 15 whereby chamber 20 is provided with an open space or portion facing furnace shell 15 and disposed circumferentially of shell 15 substantially in a horizontal plane. The open portion thus defines an edge along the length of chamber 20 and spaced from furnace shell 15. In order to provide a circumferentially continuous flow of cooling liquid at a reduced velocity onto the furnace shell there is included a weir in the form of baffle plate 30. Plate 30 is spaced from furnace shell 15 and extends for the entire length of chamber 20 and can be attached at one end to bottom wall 21 in a suitable manner, one particular arrangement to be described hereafter. For convenience in assembly, weir 30 can comprise a plurality of plates joined endto-end so as to encircle furnace shell 15. Alternatively, and if adjustability is not desired, weir 30 can comprise an integral extension of bottom wall 21 bent or formed so as to extend into chamber 20 Weir 30 preferably is inclined relative to chamber bottom wall 21 and in a direction upwardly away from furnace shell 15, but also could be disposed in a plane perpendicular with respect to the plane of bottom wall 21.
The cooling apparatus of the present invention also includes a sealing strip or wiper 35 of resilient material encircling the furnace shell and connected to chamber 20, strip 35 being disposed in wiping relation to the furnace shell when chamber 20 is attached thereto. in particular, sealing strip 35 is connected to chamber 20 so that one edge of the strip is at or near the edge of the open space in chamber 20. The opposite edge of sealing strip 35 is in wiping contact with the outer surface of furnace shell 15. That is to say, strip 35 contacts shell 15 but resiliently flexes to distribute a thin film of cooling liquid thereacross. Actually, sealing strip, 35 would comprise a plurality of sections in end-to-end contact whereby the composite strip extends for the entire circumference or length of chamber 20. Each of the sections, in turn, would be attached to chamber 20 in a suitable manner, one arrangement of which will be described hereafter.
Sealing strip 35 can be of any resilient waterproof material which will reflex slightly in response to the force or weight of liquid thereon so as to allow a thin sheet or film of the liquid to flow from chamber 20 onto the outer surface of furnace shell 15. The resilient restoring force of the seal distributes the liquid in a thin film or sheet across the shell. Strip 35 preferably is of rubber and inclined in the manner shown in FIG. 1, that is disposed in a plane parallel or coincident with the plane or weir 30. It should be noted that strip 35 alternatively could be disposed in a generally horizontal plane with one edge thereof in wiping contact with the outer surface of furnace shell 15.
A preferred arrangement for adjustably attaching baffle plate 30 and sealing strip 35 to chamber bottom wall 21 is shown in the enlarged views of FIGS. 3 and 4. Bottom wall 21 terminates in an inclined lip 36 which is spaced from shell 15 in a manner defining an open space or portion in chamber 20 as previously described. Baffle plate 30 is attached to lip 36 by a suitable fastener 37. In addition the extent to which baffle plate 30 projects into chamber 20 can be adjusted by having fastener 37 of the releasable type, for example a bolt and nut, and by the provision of a slot in either plate 30 or lip 36 disposed along the direction of desired adjustment and adapted to receive fastener 37. Sealing strip 35, in turn, is attached to baffle plate 30 by a suitable fastener 38 and, in addition, the extent to which it projects toward furnace shell l preferably is made similarly made adjustable by the provision of a releasable fastener and elongated slot in either strip 35 or plate 30. A relatively narrow plate 39 can be included and secured to sealing strip 35 by fastener 38 to prevent leakage through the adjustment slot.
The cooling arrangement of the present invention finally comprises an annular trough 40 for receiving cooling liquid after it has traveled along furnace shell a given distance. In this particular illustration trough 40 includes a bottom wall 41 which conveniently is supported by an annular ledge 42 provide in furnace lining 14 between tuyere jacket 15b and bosh jacket 15c. Trough 40 includes an outer sidewall 43 which encircles bosh jacket portion I50 and is generally concentric therewith. The lower portion of jacket l5c defines an inner sidewall of trough 40. A conduit 44 extends through outer sidewall 43 for the purpose of draining liquid from trough 40, and it should be noted that additional drain conduits can be provided circumferentially spaced around trough 40.
The cooling arrangement thus described causes a film or sheet of cooling liquid to flow along a particular zone or portion of the furnace shell 15, in particular bosh jacket l5c which is directed downwardly and inwardly. A similar arrangement is included in the illustration of FIG. 1 for coolinghearth jacket portion 15a of furnace shell 15 wherein the primed numbers indicate similar elements. A liquid-distributing chamber 20' encircles hearth jacket 15a and includes a bottom wall 21 and upstanding sidewall 22'. ln this particular arrangement a separate ring-shaped member 50 provides a top cover for chamber 20. A liquid supply conduit 25 extends through sidewall 22' and additional conduits can be included for the same purpose. A weir in the form of baffle plate 30' extends into chamber 20' and a resilient sealing strip 35 extends from chamber 20' into wiping contact with the outer surface of shell portion 15a. Baffle plate 30' and sealing strip 35' can be adjusted by an arrangement like that shown in FIGS. 3 and 4. A trough 40' and outlet conduit 44' are included for receiving and draining cooling liquid after its travel down shell portion 15a.
The cooling apparatus of the present invention operates in the following manner. Cooling liquid is introduced to compartment 20 through conduit 25 at a discrete location relative to the continuous outer surface of furnace shell 15. In reality, several circumferentially spaced conduits supply liquid to chamber 20 at a corresponding number of discrete locations. The liquid is delivered to the interior of chamber 20 on the side of weir 30 remote from the furnace. The liquid proceeds to fill the interior region of chamber 20 defined by bottom wall 21, sidewall 22 and weir 30, and when the liquid rises to a sufficient level it overflows weir 30 and travels downwardly over the surface thereof and toward sealing strip 35.
The inclusion of weir 30 in chamber 20 provides two significant results which insure an even cooling of furnace shell 15. One is a continuous introduction of cooling liquid to furnace shell 15 around the circumference thereof. Cooling liquid is introduced to chamber 20 discontinously in a plurality of separate flows by virtue of the discrete spacing of inlet conduits, but by accumulating in chamber 20 and rising to a level sufficient to overflow weir 30, the liquid flows over the top edge of weir 30, which is concentric with furnace shell 15, a circumferentially continuous manner. This, in turn, provides a continuous sheet or film of cooling liquid around the circumference of furnace shell 15 thereby insuring an even cooling thereof.
A second result provided by the inclusion of weir 30 in the chamber is the elimination of the component of liquid velocity contributed by its flow through inlet conduit 25. As a result, the only velocity is that contributed by gravity as the liquid flows down furnace shell 15. This net reduction in velocity of the liquid film reduces the possibility of disturbances in the continuity of the film which otherwise would cause uneven cooling. The lowering of the liquid velocity also reduces the change of portions of the film being deflected from its path by any irregularities which may be present on the surface of the furnace shell. The effect of weir height on these results is easily varied by means of the adjustment arrangement described in connection with FIGS. 3 and 4.
Upon overflowing the top edge of weir 30, the cooling liquid flows down over the surface thereof and onto sealing strip 35, the edge of which in wiping contact with furnace shell 15. The resiliency of sealing strip 35 causes it to flex slightly in response to the weight or force of liquid thereon whereby the outer edge thereof will move slightly out of contact with furnace shell 15 and thereby cause a thin film or sheet 51 of liquid to flow downwardly along furnace shell 15. The cooling liquid ultimately is collected in trough 40 from which it is drained by conduit 44.
The provision of sealing strip 35 in the apparatus of the present invention provides several results heretofore unobtainable with arrangements of the flowing liquid film type. One is the ability to cool a surface which is directed downwardly and inwardly from the distributing chamber such as bosh jacket portion is c of the furnace shell. This is because the edge of sealing strip 35 is in wiping contact with the surface to be cooled and due to the resiliency thereof flexes out of contact herewith only by an amount determined by the force or weight of liquid thereon and in a manner wiping the liquid on the shell. ln other words, the wiping edge of sealing strip 35 becomes spaced from the surface to be cooled by a distance detennined by the flow properties of the liquid and the resilient restoring force of the strip. This, in turn, prevents liquid from flowing outwardly around the edge of sealing strip 35 and otherwise away from furnace shell 15.
In arrangements of this general type heretofore available, an edge of the liquid-distributing component encircles the surface to be cooled and is spaced therefrom. When applied to a downwardly and inwardly directed surface such as bosh jacket l5 c, such arrangements function improperly because the liquid, due to surface tension effects, flows around and outwardly from the edge, clinging to the surface of the distributing component and thus away from the surface to be sealed.
The arrangement of the present invention also functions equally well in, cooling of generally vertical as well as downwardly outwardly directed surfaces.
Another significant advantage provided by the apparatus of the present invention is that it is convenient and easy to maintain. The resiliency of sealing strip 35 enables a cleaning implement to be inserted between furnace shell and strip 35 by a worker with a minimum of effort and as he walks around the furnace. Thus, any impurities such as dirt or scale in the cooling liquid which tend to accumulate in the cooling apparatus can be removed easily therefrom. If necessary, the edge of strip 35 can be moved a distance from shell 15 by means of the adjustable arrangement described in connection with FIGS. 3 and 4. Actually, the accumulation of large amounts of impurities may be minimized or prevented entirely due to the flexing ability of sealing strip 35. The weight of any accumulation between strip 35 and furnace shell 15 may cause strip 35 to flex by a greater amount thereby allowing the flow of liquid to carry the accumulation therefrom. As a result, the cooling apparatus of the present invention is readily compatible with recirculating liquid systems which are becoming increasingly popular.
Should any portion of sealing strip 35 become worn, the necessary replacement is a simple task whereby the particular portion of segment of strip 35 can be easily removed and a one substituted. This plus the fact that strip 35 is of a relatively low cost material such as rubber renders this aspect of maintenance economical.
It is therefore apparent that the present invention accomplishes its intended objects. While a single embodiment of the invention has been described in detail, this has been done by way of illustration without thought of limitation.
1. Apparatus for cooling the exterior shell of a furnace comprising:
a. an annular liquid-distributing chamber adapted to be attached to the furnace so as to encircle the exterior shell thereof and having a liquid discharge portion adjacent the furnace shell;
b. a sealing strip of resilient material encircling the furnace shell and connected to said chamber, said strip being disposed in wiping relation to the furnace shell when said chamber is attached thereto; and
c. means for delivering cooling liquid to the interior of said chamber;
(1. whereby in response to the weight of cooling liquid thereon said sealing strip flexes so as to cause a film of cooling liquid to flow downwardly along the furnace shell.
2. The cooling apparatus defined in claim I further including means for receivin and draining liquid adapted to be attached to said furnace be ow said chamber so as to receive cooling liquid flowing downwardly along the shell.
3. The cooling apparatus defined in claim 1 further including a weir in said chamber extending along the entire circumferential length thereof and positioned so as to deliver a circumferentially continuous flow of cooling liquid onto said sealing strip.
4. The cooling apparatus defined in claim I wherein said sealing strip comprises a plurality of rubber sections positioned in end-to-end contact.
5. Apparatus for cooling the exterior shell of a furnace comprising:
a. an annular liquid-distributing chamber adapted to be attached to the furnace so as to encircle the exterior shell, said chamber having a bottom wall which terminates a distance from the shell so as to define an open space therebetween and disposed circumferentially thereof;
b. a sealing strip of resilient material encircling the furnace shell, said strip being attached to said chamber bottom wall and being disposed so as to extend therefrom into wiping contact with the furnace shell when said chamber is attached thereto;
c. a weir in said chamber attached to said chamber bottom wall and extending for the entire length of said chamber; and
. conduit means for delivering cooling liquid to the interior of said chamber on the side of said weir remote from the furnace.
6. The cooling apparatus defined in claim 5 further including trough means for receiving and draining liquid adapted to be attached to said furnace below said chamber so as to receive cooling liquid flowing downwardly along the shell.
7. The cooling apparatus defined in claim 5 wherein said chamber bottom wall is disposed in a horizontal plane and wherein said weir and said sealing strip are inclined relative to said bottom wall.
8. The cooling apparatus defined in claim 5 wherein said weir and sealing strip are adjustably attached to said chamber bottom wall.
9. The cooling apparatus of claim 1 on a furnace having a downwardly inclined shell portion, said sealing strip being in wiping relation to said downwardly inclined shell portion.