US3252448A

US3252448A - Forced circulation water-cooled furnace door with monolithic lining

Info

Publication number: US3252448A
Application number: US469615A
Authority: US
Inventors: Ottwin L Braun
Original assignee: Reliance Steel Products Co
Current assignee: Reliance Steel Products Co
Priority date: 1965-07-06
Filing date: 1965-07-06
Publication date: 1966-05-24
Anticipated expiration: 1983-05-24

Description

O. L. BRAUN FORCED CIRCULATION WATER-COOLED FURNACE DOOR WITH MONOLITHIC LINING May 24, 1966 2 Sheets-Sheet 1 Filed July 6, 1965 Pa -.L J-:.:r

W mm M EN mm H m N m ATTORNEYS y 24, 1966 o. L. BRAUN FORCED CIRCULATION WATER-'CQOLED FURNACE DOOR WITH MONOLITHIC LINING Filed July 6, 1965 2 Sheets-Sheet OTTWIN L. BRAUN.

ATTORNEYS United States Patent 3,252,448 FORCED CIRCULATION WATER-COOLED FUR- NACE DOOR WITH MONOLITHIC LINING Ottwin L. Braun, Pittsburgh, Pa., assignor to Reliance Steel Products Company, McKeesport, Pa., a corporation of Pennsylvania Filed July 6, 1965, Ser. No. 469,615 3 Claims. (Cl. 122-498) The present application is a continuation-inpart of my application Serial No. 185,960, filed April 9, 1962, now abandoned.

This invention is for a water-cooled refractory-faced furnace door which is especially designed for use on openhearth furnaces, but which is not limited to such use.

Water-cooled doors are commonly used in combination with water-cooled door frames. Consequently, when the door is closed, its periphery is in contact with watercooled metal. It is common also to construct watercooled doors with two spaced plates, one being an inner plate which faces the interior of the furnace, and one being an outer plate that faces the exterior. The two plates have their peripheral edges turned inwardly and welded in such manner that the inner plate is recessed and surrounded by a hollow rim. Water is circulated in the space between the two plates, including the rim to cool the door. The recess so formed on the inner face of the door is filled with refractory to protect it from the furnace heat. Various arrangements have heretofore been provided to provide keys to retain the refractory panel in place, including water-cooled studs and ribs of various kinds. Such a construction is shown in my application Serial No. 142,371, filed October 2, 1961, now Patent 3,156,218, granted November 10, 1964.

The present invention relates to such a door, and provides an improved construction in which water-cooled keys are provided for forced circulation of cold water therethrough in such manner that the central area of the door is most effectively cooled and the cooling water circulated in a manner-to best utilize the flow of water for cooling the entire door. This is accomplished by dividing the stream of incoming water in such manner that one part goes first to the central area of the door and then flows laterally toward the sides, the circulation being forced. The other part of the stream enters the space between the two plates forming the door, and the first stream is discharged into the second in this space to create turbulence and prevent laminar flow. The combined stream is withdrawn through a common discharge.

The invention may be more fully understood by reference to the accompanying drawings, wherein:

FIG. 1 is a front elevational view of the furnace door;

FIG. 2 is a top view of the door partly in section;

FIG. 3 is a vertical sectional view of the door taken along the lines III-III of FIG. 1 looking in the direction of the arrows;

FIG. 4 is the rear view of the furnace door prior to the application of a monolithic lining;

FIG. 5 is a fragmentary sectional view taken along the lines VV of FIG. 4, but with a monolithic lining cast in situ;

FIG. 6 is a fragmentary sectional view taken along the lines VIVI of FIG. 4;

FIG. 7 is a fragmentary sectional view takenalong the lines VII-VII of FIG. 4; and

FIG. 8 is a view similar to FIG. 7 but showing the opposite side of the door and illustrating a modified construction.

Referring now to the drawings Where like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1, which illustrates a preferred embodiment, a furnace door 11 suit- 3,252,443 Patented May 24, 1966 sists of a rigid frame portion 16 having a recess 17 within which is rammed a refractory lining 18, FIG. 5. The rigid frame portion 16 is composed of the front or outer plate 13 with a rearwardly or inwardly-turned peripheral flange 19 which is continuous around the top, bottom, and sides of the door, and a back or inner plate 21 which is spaced from the front plate. The inner plate 21 has an inwardly and laterally-extending peripheral portion 22, the edge of which is sealed to the flange 19 of the front plate 13. Accordingly, the. front plate is separated from the back plate a sufficient distance to form a cavity or chamber 23 which extends across the face of the door as shown in FIG. 1 and across the sides,.t0p and bottom of the door by the spacing between the peripheral portions 22 and flange 19 of the inner and outer plates, respectively.

Fixed within the recess 17 to the inner plate 21 are horizontally-spaced ribs 24 of trapezoidal cross-section, for example, flow connected to vertically aligned, centrally-disposed keys comprising the rib 25. Both the horizontal ribs 24 and the vertical keys 25 are suitably sealed by welding to the recessed exposed area of the inner plate 21 of the door. The horizontal ribs 24 open into

side channels

26 and 27 of the door as shown best in FIGS. 4 and 7.

An inlet conduit 28 is passed through the top of the door and is coupled to a T fitting 29, which is contained wholly within the side channel 27 at the top of the door 11. From the T fitting 29 a horizontally-extending pipe 31 is posi tioned within the top channel 32 of the door and opens only into the vertical keys 25. A conduit 33 is also connected to the T fitting 29 and depends vertically within the side channel 27 of the door to open at point just above the bottom channel 34 of the door. An outlet pipe 35 is connected through the top of the door at the side opposite the inlet conduit 28 and is in open communication with the side channel 26. The top channel 32, bottom channel 34 and

side channels

26 and 27 form a continuous hollow rim about the door periphery which opens into the chamber 23.

When the door is lifted to the open position, the bottom is still exposed to the furnace heat so that unlikeother areas of the door, it is practically continuously exposed, for which reason it is especially, and in this regard, a maximum amount of circulation is necessary in this area of the door. Water is therefore forced under pressure through the inlet conduit 28 with more than fifty percent of the volume of flow continuing downwardly through the conduit 33 to empty into the bottom section of the door, the balance being directed through the horizontal pipe 31 through the vertical key 25 and horizontal ribs 24 and outwardly through apertures or ports 36 into the

side channels

26 and 27. For maximum cooling it was discovered that 62 percent of the incoming water should be fed to the bottom section of the door through the conduit 33. The horizontal ribs and keys embedded in the monolithic lining assist in supporting the monolithic lining particularly when the lining approaches a fiuxing temperature, while at the same time the forced circulation of cold incoming water down the center of the door, first through the vertical keys 25 and then laterally to each side, effectively cools the central area of the door. Water discharged under pressure from the ends of the horizontal ribs into the space between the two plates combines with and imparts turbulence to the body of water inthis space, disturbing laminar or quiescent flow, and aiding in avoiding any stagnant areas. Suitable cleanout openings 37 are provided through the bottom of the door.

As shown in section in FIG. 5, the refractory monolithic lining is positioned in the recess and is anchored therein principally by means of the ribs 24. In some instances it has been found desirable to utilize welding studs 38, which project from the ribs 24 and the keys 25 at regular intervals and which are also embedded in the lining material in order to more effectively tie the lining onto the door.

The metal structural members of the door in direct surface contact with the lining 18 such as the back plate 21,

.keys 25, and ribs 24, transfer by conduction the heat absorbed by the lining 18, which has radiated from the combustion zone of the furnace, for example, to a coolant such as water which is circulated in the chamber 23,

channels

26, 27, 32 and 34, from the ribs 24 and the conduit 33. The water is fed directly via the conduit 33 to the bottom area of the door in an amount greater than that fed through the pipe 31, keys 25, and ribs 24. In this manner the circulation system indicated by flow arrows in FIG. 4 is most effective in cooling the door lining, thereupon extending the useful period of service of the door.

In the modification shown in FIG. 8 where like reference numerals are used for those parts that correspond to FIG. 7, the passages in the horizontal keys open directly into the space 23 through ports 22a in the panel 21 near the outer ends of the keys, instead of into the

vertical channel portions

26 and 27. more effectively imparts turbulence to the water in the chamber 23 and more effectively diffuses the two streams of water before the water is carried out through the common discharge pipe 28, especially near the central area of the door.

It is manifest that the above-described embodiment of the invention is merely illustrative and that numerous modifications may be made within the spirit and scope of the invention.

I claim:

1. A furnace door having a top, bottom and sides and having front and rear faces comprising spaced front and rear plates defining between them a water-circulating space, the two plates having marginal flanges that are sealed together forming a hollow rim about the rear face of the door defining a refractory receiving recess about the rear plate, the hollow interior of the rim forming a part of said water-circulating space between the two plates, a pair of transversely-extending spaced hollow ribs in the recess sealed to the rear plate forming water-circulating ducts across the rear plate, a vertical rib in the recess extending downwardly from said hollow rim from the top approximately midway between the sides of the door and opening into said transversely-extending hollow rim, a water supply pipe extending down the interior of the door at one side and terminating near the bottom for introducing water directly into the circulating space between the plates, a branch pipe leading from said water supply pipe through the water-circulating space at the top of the door and opening only into said vertical rib whereby water therefrom flows from the supply pipe into the vertical rib at the center of the door and thence from the vertical rib it divides first into each of the transverselyextendin-g ribs where the stream again divides and the flow is from the center laterally toward each side of the door, the ducts provided by said transversely-extending ribs opening through ports adjacent-their ends into the water- This arrangement circulating space between the plates so that the water discharged from the ducts is forced into the water in said space to commingle with the water introduced directly into said space through said supply pipe, said ribs forming pockets over the recessed area of the door and watercooled keys for retaining refractory material in the recessed area of the door over and around the keys, said water supply pipe having an external connection near the top of the door for connection with a source of water under pressure, and a water discharge pipe leading from the water-circulating space through the door at the top at the side opposite the water supply pipe.

2. A water-cooled furnace door comprising:

(a) inner and outer spaced metal plates having inwardly-turned edge'fianges, the plates providing between them a water-circulating space,

(b) said inwardly-turned flange portions being welded together to provide a hollow rim about the door that forms a continuous part of the water-circulating space between the plates, a recess being formed about the exposed face of the inner plate surrounded by said rim,

(c) a plurality of vertically-spaced hollow keys secured to said inner plate within the recess and extending horizontally thereacross from one side to the other and forming with the inner plate horizontal ducts,

(d) a duct-forming vertical hollow key in the recess similar to the horizontal keys extending down from the rim at the top of the door at the center thereof and intersecting and opening into each of the horizontal ducts,

(c) said horizontal ducts having discharge ports near the opposite ends thereof through which water may be discharged from said ducts into the water-circulating space between the plates,

(f) a water supply pipe extending through the door at the top, said pipe having one branch inside said space extending downwardly inside the door and terminating in the lower portion of said space,

(g) said pipe having a second branch inside said space opening only into said vertical duct-forming key near the top of the door and so connected that the stream of water supplied thereto flows down the vertical duct and the flow is then divided into each of the horizontal ducts, whereby such water is coldest at the central area of the door and flows laterally from the center of each horizontal duct in opposite directions toward the sides, finally discharging into and effecting the flow pattern of the water entering said door through the first branch,

(h) an outlet pipe for the discharge of water in the upper part of the door spaced from the supply pipe, and

(i) a refractory lining in the said recess on the inner face ofthe door confined therein by said rim and the duct-forming keys.

3. A water-cooled furnace door as defined in claim 2 in which said branch pipes are so proportioned that the flow of water in the first branch is greater than the flow through the second branch.

References Cited by the Examiner UNITED STATES PATENTS 806,381 12/1905 Weller l22497 2,766,736 10/1956 Del Buono 122-498 2,864,345 12/1958 Reighart 122498 3,019,775 2/1962 Robinson 122498 0 KENNETH w. SP'RAGUE, Primary Examiner.

Claims

1. A FURNACE DOOR HAVING A TOP, BOTTOM AND SIDES AND HAVING FRONT AND REAR FACES COMPRSING SPACED FRONT AND REAR PLATES DEFINING BETWEEN THEM A WATER-CIRCULATING SPACE, THE TWO PLATES HAVING MARGINAL FLANGES THAT ARE SEALED TOGETHER FORMING A HOLLOW RIM ABOUT THE REAR FACE OF THE DOOR DEFINING A REFRACTORY RECEIVING RECESS ABOUT THE REAR PLATE, THE HOLLOW INTERIOR OF THE RIM FORMING A PART OF SAID WATER-CIRCULATING SPACE BETWEEN THE TWO PLATES, A PAIR OF TRAVERSELY-EXTENDING SPACED HOLLOW RIBS IN THE RECESS SEALED TO THE REAR PLATE FORMING WATER-CIRCULATING DUCTS ACROSS THE REAR PLATE, A VERTICAL RIB IN THE RECESS EXTENDING DOWNWARDLY FROM AID HOLLOW RIM FROM THE TOP APPROXIMATELY MIDWAY BETWEEN THE SIDES OF THE DOOR AND OPENING INTO SAID TRANSVERSELY-EXTENDING HOLLOW RIM, A WATER SUPPLY PIPE EXTENDING DOWN THE INTERIOR OF THE DOOR AT ONE SIDE AND TERMINATING NEAR THE BOTTOM FOR INTRODUCING WATER DIRECTLY INTO THE CIRCULATING SPACE BETWEEN THE PLATES, A BRANCH PIPE LEADING FROM SAID WATER SUPPLY PIPE THROUGH THE WATER-CIRCULATING SPACE AT THE TOP OF THE DOOR AND OPENING ONLY INTO SAID VERTICLA RIB WHEREBY WATER THEREFROM FLOWS FROM THE SUPPLY PIPE INTO THE VERTICAL RIB AT THE CENTER OF THE DOOR AND THENCE FROM THE VERTICAL RIB IT DIVIDES FIRST INTO EACH OF THE TRANSVERSELYEXTENDING RIBS WHERE THE STREAM AGAIN DIVIDES AND THE FLOW IS FROM THE CENTER LATERALLY TOWARD EACH SIDE OF THE DOOR, THE DUCTS PROVIDED BY SAID TRANSVERSELY-EXTENDING RIBS OPENING THROUGH PORTS ADJACENT THEIR ENDS INTO THE WATERCIRCULATING SPACE BETWEEN THE PLATES SO TAHT THE WATER DISCHARGED FROM THE DUCTS IS FORCED INTO THE WATER IN SAID SPACE TO COMMINGLE WITH THE WATER INTRODUCED DIRECTLY INTO SAID SPACE THROUGH SAID SUPPLY PIPE, SAID RIBS FORMING POCKETS OVER THE RECESSED AREA OF THE DOOR AND WATERCOOLED KEYS FOR RETAINING REFRACTORY MATERIAL IN THE RECESSED AREA OF THE DOOR OVER THE AROUND THE KEYS, SAID WATER SUPPLY PIPE HAVING AN EXTERNAL CONNECTION NEAR THE TOP OF THE DOOR FOR CONNECTION WITH A SOURCE OF WATER UNDER PRESSURE, AND A WATER DISCHARGE PIPE LEADING FROM THE WATER-CIRCULATING SPACE THROUGH THE DOOR AT THE TOP AT THE SIDE OPPOSITE THE WATER SUPPLY PIPE.