JPS5952020B2 - Ladle heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a method in which a flame is directed into the chamber of a ladle and hot gases heat the incoming air and fuel forming the flame through a heat exchanger. This invention relates to a ladle heating device, such as one that is discharged from a ladle.

References to Related Applications Priority is claimed to U.S. Patent Application No. 22,687, filed March 21, 1979, and U.S. Patent Application No. 0,609,374, filed November 8, 1979.

BACKGROUND OF THE INVENTION In the ferrous and non-ferrous molten metal industry, ladles and similar metal receivers, such as holding vessels and vacuum furnace chambers, receive charges of molten metal.

Typically, the receiver is lined with a refractory material to prevent solidification of the inner surface of the metal upon contact, and to protect against the refractory liner of the receiver between the metal and the cold inner surface of the receiver. In order to avoid thermal shock and thus prevent deterioration of the liner, it is desirable to preheat the receiver before receiving molten metal.

The preheated ladle is also used in a ladle where the metal is
It reduces heat loss during transport from the furnace to the injection location, thus helping to maintain the molten metal at a sufficiently high temperature for use in the casting machine or mold.

The usual conventional technique for heating ladle and other molten metal receivers prior to charging molten metal is to direct an open natural gas flame into the open chamber of the ladle.

This allows the combustion gases from the open flame-heating blade to escape into the surrounding atmosphere.

Thus, a significant amount of thermal energy can be dissipated without its useful use, resulting in a disproportionate amount of gas being wasted.

Furthermore, the ladle is heated too much in some areas and not heated enough in other areas.
With an open flame, it is difficult to heat the ribs evenly.

Additionally, if the ladle is first heated and then achieves its desired temperature before it is time to introduce molten metal into the ladle, the ladle is maintained in its heated state. Sometimes it is desirable to do so.

In this situation, the open flame heating procedure continues to waste energy and hot spots are more likely to form within the ladle.

SUMMARY OF THE INVENTION Briefly stated, the present invention comprises an improved apparatus for heating ladles and similar molten metal receptors in which a sealing member is provided on the rim of the ladle. The air is directed through the heat exchanger and the heat exchanger and is mixed with fuel to form a flame within the livery chamber, and gases from the flame are directed through the heat exchanger and the heat exchanger. It is discharged back through the container.

The heat in the exhaust gas is partially subtracted into the heat exchanger by being transferred to the incoming air, and the flame formed in the ladle causes the inner surface of the chamber to Thermal cleaning is controlled in such a way as to avoid hot and cold spots.

Exhaust gas is directed through an exhaust hole in the sealing member that is approximately coaxial with the rim of the ladle.

In one embodiment of the invention, the sealing members formed to the rim of the ladle each consist of a network of refractory fiber modules formed from a web of refractory fibers, the webs comprising an accordion fold. It is formed of.

and the modules are arranged on a common surface,
The folds of each module are maintained in compression by the closure support frame.

When the sealing member is compressed into abutment with the rim of the rivet, the module tends to conform to the shape of and seal around the rim of the rivet.

The ability of the sealing member to be compressed tends to compensate for irregularities in the ladle rim that may be caused by cuts or rough surfaces present on the ladle rim or by slug formation.

According to one embodiment of the invention, the heat exchanger is shielded from direct radiation from the flame in the ladle chamber.

The heat exchanger is optionally multi-stage with a first heat exchanger receiving the hottest gas formed of a material having a thermal resistance superior to that of subsequent heat exchangers. Consists of a heat exchanger.

The apparatus of the invention includes means for sensing the temperature of the ladle and means responsive to the temperature sensing means for adjusting the output of the fuel burner to maintain the ladle at a predetermined temperature. There is.

The device also includes a means for sensing the amount of oxygen passing through the exhaust outlet passage and a variable means for minimizing the amount of unburned oxygen in the exhaust outlet passage in order to maximize the efficiency of combustion. and means responsive to the oxygen sensing means for adjusting the composition of the fuel and air mixture provided to the fuel burner by the fuel supply means.

Such regulating means responsive to the temperature of the ladle and the amount of unburned oxygen are interrelated in the device according to the invention, so that the regulation responsive to the unburned oxygen is such that the operation of the burner is This is done at any intensity taken by regulating means responsive to the temperature of the ladle.

Thus, the ladle heating device according to the invention has the advantages of energy efficiency resulting from careful control of fuel consumption, recovery of wasted heat and the ability to maintain the ladle at a desired high temperature with minimal energy consumption. .

It is thus an object of the present invention to provide a heating device that efficiently heats ladle and other chambers with flame in a controlled environment.

Another object of the present invention is to be effective in forming a seal around the rim of a ladle of different sizes and configurations and to prevent chips, crevices or other defects present in the rim of the ladle. Improved integrity and to compensate for the formation of slag on the rim of the ladle and to avoid the propagation of noise due to gas or irritation escaping between the ladle rim and sealing member assembly. It is an object of the present invention to provide a ladle heating device with a closed assembly.

Another object of the present invention is to provide a method and apparatus for recovering and using wasted heat generated by a ladle heating device.

Another object of the present invention is to provide a method and apparatus for heating a ladle in which a control device is provided to efficiently maintain the ladle at a predetermined temperature.

Another object of the invention is to provide a ladle heating device that is inexpensive to construct and operate, conserves energy, is durable, and easy to repair.

Other objects, features, and advantages of the present invention will become more apparent from the following specification, taken in conjunction with the accompanying drawings.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a ladle and a ladle heater, with some parts omitted to illustrate the inside of the ladle and ladle heater of the present invention. An embodiment is shown. FIG. 2 is a rear view of the ladle heater of FIG. 1, with the carriage omitted. 3 is a side view of the ladle heater of FIG. 1 with the carriage removed; FIG. FIG. 4 is a front view of the ladle heater of FIG. 1 with the carriage removed, showing the surface of the closure assembly; FIG. 5 is a detailed exploded perspective view of several refractory fiber modules and the upright sealing support plate of the ladle heater of FIG. 1; FIG. 6 is a perspective view similar to FIG. 1, illustrating a second embodiment of the ladle heater. FIG. 7 is a perspective view of a third embodiment of the ladle heater. FIG. 8 is a schematic diagram of a control device for controlling the operation of the ladle heaters of FIGS. 1 to 7. FIG. FIG. 9 is a side view and shows a portion of the fourth embodiment of the ladle heater in cross section. FIG. 10 is a side view of a fifth embodiment of the ladle heater. FIG. 11 is a schematic diagram of a control device for controlling the operation of the ribbed heaters of FIGS. 9 and 10. FIG. DETAILED DESCRIPTION To refer in more detail to the drawings, over several figures:
Like numerals indicate like parts, and FIG. 1 illustrates a ladle heater for heating a ladle, such as ladle 11. FIG. The ladle 11 is mounted on a support block 12 and a shim 13,
It is shown as being placed on its side, and with its rim 14 facing the side. The ladle 11 is lined with refractory brick or other suitable heat resistant material. ) The rim 14 is generally circular in shape, but can have an injection spout or other non-circular shape. In some instances, slag formation is present on the ladle rim 14, or said ladle rim is chipped, cracked, or otherwise.
The shape is incomplete. The ladle heater 10 has a carriage 18 mounted on wheels 19, said wheels movable along a track 20. The sealing assembly 21 is mounted on the carriage 18 , the heat exchanger 22 is also mounted on the carriage 18 , the blower 24 is mounted on the carriage 18 and the air conduit means 25 is blower 2
a blower exhaust duct 26 extending upwardly from 4; a heat exchanger tube 29; a second heat exchanger header 30 disposed on the other side of said heat exchanger tube; Vessel 29
branch conduits 31 and 32 extending downwardly through the sealing assembly 21 and rotating inwardly through the sealing assembly 21. Burners 35 and 36 communicate with air conduit means at the intersections of branch conduits 31 and 32 and sealing assembly 21. A filter 34 is mounted on the inlet of the blower 24. The exhaust gas conduit means 38 connects the burners 35 and 36 with a duct member 4o extending firstly in a horizontal leg 41 through the aperture 39 and then upwardly as far as the heat exchanger 22 in a vertical leg 42. Through the sealing assembly 21 between
An aperture 39 is defined. An exhaust duct 44 then extends upwardly from the heat exchanger to disperse the exhaust gases from the ladle heater. The damper 45 is located inside the exhaust duct 44,
The exhaust gas conduit means is arranged to selectively prevent or restrict the movement of gas. As will be apparent, the heat exchanger 22 is connected to the exhaust gas conduit means 38.
The flame 15 in the chamber 15 of the ladle 11 does not radiate heat directly to the heat exchanger. Also, the duct member 40 of the exhaust gas conduit means is thermally insulated. A frame structure 46 is mounted on the carriage 18 and includes various upright, vertical and diagonal support beams for supporting the seal assembly 21 and the heat exchanger 22.
It contains air conduit means, exhaust gas conduit means and associated components thereof. As illustrated in FIGS. 2 and 3, the sealing assembly 21
The upright lateral frame elements 49 and 50, the upper horizontal frame element 51. and a lower horizontal frame element 52 and a containing support frame 48. Upright steel support plate 54 has its edges in abutment with frame elements 49-52. Frame elements 49-52 are channel members each having one flange abutting upright steel plate 54 and its outer flange disposed in common plane and forming a frame rim. have. A network of refractory fiber modules or insulation blocks 55 is mounted within the support frame 48 and forms a refractory fiber surface on the inside of the frame element. The adjacent frame element 49-52, the refractory fiber module 55, is partially connected to the channel-shaped beam 49-5.
2, each module 5
5 is attached to an upright steel support plate 54. Each refractory fiber module or batt 55
(See Figure 5) is formed from a web or blanket of refractory fibers, the web being in the form of an elongated sheet. The sheet is folded in a zigzag or accordion arrangement to have a series of layers 56 with side edges 58 and folds 59 exposed on the front side and similar folds 60 on the rear side of the module. . The modules 55 are rectangular in shape and are each held in an accordion-fold configuration by a band wrapped around the module until it is mounted within the support frame 48 and then held in an accordion-fold configuration. , the band is removed. The band tends to hold the module in compression until the band is removed. Each of the modules includes a support bar 61 that extends between the layers 56 at the fold line 60 at a later stage of the module, and a connecting tab 62 extends from this and projects from the layer plate at the fold line 60. ing. Channel-shaped connector blanket 63 defines a slot therethrough for receiving support rod tab 62. When the tabs 62 are inserted into the apertures, they
Planchers 1-63 are bent to be fixed to the module. The channel-shaped blanket channels are then attached to protrusions 64 mounted on the upright support plate 54 to secure the module to the support frame 48. A more detailed description of similar insulation blocks can be found in U.S. Pat.
No. 001996. The module 55 is loaded within the support frame. Once these are properly positioned and packed within the support frame, the oars (not shown) are removed and the modules remain compressed due to their abutment with each other. easy to become. It goes without saying that each module 55 is oriented at right angles to the fold line of the next adjacent module. Thus, a parkerato or other crease effect is formed across the frame structure of the closure assembly. Each of the layers 56 is generally cubic in shape, and in the disclosed embodiment is approximately one square foot. However, other dimensions and other shapes can be used if desired. When the ladle heater 10 and ladle 11 are moved into engagement with each other as shown in FIG. 1, the ladle rim 14 is moved into abutment with the closure assembly 21. The sealing assembly 21 has a frame structure of refractory fiber modules 55, each formed in an accordion arrangement, as shown in FIG. They tend to protrude and migrate into the surface of the seal assembly being formed. As the rim is pushed against the module 55, a depression is formed in the refractory fiber. The rim and seal assembly are moved together with a force of 2 pounds per square inch or more, preferably 4 to 10 pounds per square inch, so that the rim It tends to penetrate the surface and a good seal is required around the berim. The desired depth of the recess in the closure assembly is approximately 3 inches. The density of refractory fiber modules is approximately 8 pounds per square inch. Thus, a strong seal is created around the ladle rim 14 and a substantial thickness of refractory fiber material remains between the ladle rim and the upright steel plate 54 supporting the fiber module 55. There is. Module 55 not directly engaged by the ladle rim
is not compressed by the rim and tends to retain all of its thermal resistance characteristics, thus closing the ladle aperture on the inside of the ladle rim, so that the sealing assembly closes the exhaust aperture 39. functions as a lid or closure wall for the chamber of the ladle. Through the openings burners 35 and 36, temperature testing or other elements protrude. With this arrangement, the refractory fiber web material of module 55 shields other components of the ladle heater from direct heat radiation from the flame inside the ladle. Preferably, said ladle 11 and sealing assembly 21 are arranged such that the aperture 39 of the exhaust gas conduit means 38 is arranged coaxially with respect to said rim 14, so that: The exhaust gas is directed from the ladle chamber 15 through the center of the aperture formed by the ladle rim 14. The burners 35 and 36 are arranged on opposite sides of the aperture 39, so that the flame is injected into the chamber on the opposite side of the exhaust hole 39. Preferably, the burners 35 and 36 are located in the ladle chamber 1.
5 is constructed and arranged to direct the flames toward the central portion of the bottom of the ladle, said flames merging with each other at the bottom wall of the ladle, thus The bottom surface tends to be thoroughly cleaned with flame. This tends to apply the hottest heat to the thicker bottom wall of the ladle, the flames and gases of combustion tend to sweep backwards along the annular side wall of the ladle, and finally the exhaust It is discharged via the opening 39 and over the exhaust gas conduit means 39. This tends to heat the ladle evenly; any heat that is not propagated to the ladle from its flame and gases is absorbed by the exhaust aperture 39.
is transported along with the gas. A reversible motor 53 is mounted on the carriage 18 and is in driving relation to the platform wheels 19, thus urging the sealing assembly and the rim of the ladle into a compressive relationship with each other. work as a means of Heat exchanger 22 is located in the upper portion of ladle heater 10, which is easily accessible for inspection and repair. This position of the heat exchanger also corresponds to the chamber 15 of the rib 11.
By placing it at a distance from the flame applied within the chamber, the heat exchanger does not radiate heat directly to the flame within the chamber. Thereby, the heat exchanger does not radiate any further heat, while the heat exchanger is fully exposed to convective heat from the exhaust gas traveling via the exhaust gas conduit means. Because heat exchanger 22 is formed from a porcelain material, it can withstand temperatures of over 2000 degrees Fahrenheit. When heating of the ladle is accomplished by ladle heater 10, the normal procedure is to extinguish the flame within the ladle chamber by terminating the fuel and flow to burners 35 and 36, and venting. The damper 45 in the duct 44 is closed and the ladle 11 and the ladle heater 10 are moved apart, after which the ladle 11 is oriented in an upright position and filled with molten metal or the like. transported to the desired location. When the damper 45 is closed, atmospheric air is substantially prevented from flowing through the exhaust gas conduit means 38 and the heat exchanger 22. This prevents the heat exchanger 22 from cooling too quickly, thus reducing the difficulty of damage to the heat exchanger due to rapid shrinkage. Also, if the ladle heater 10 is used again within a short period of time, the heat exchanger 22 retains a significant amount of its heat for the next cycle of operation. As illustrated in FIG. 6, in which a second embodiment of the present invention is disclosed, the heat exchanger comprises a first stage 65 disposed within the relatively low exhaust gas conduit means 38 and one A multistage heat exchanger can be constructed, with one or more additional heat exchangers arranged in series therewith. In the illustrated embodiment, the intermediate or second stage heat exchanger 66 is disposed on top of the first stage heat exchanger and the upper or third stage heat exchanger 67 is arranged above the second stage heat exchanger 66. The exhaust gases are directed sequentially through first, second and third heat exchangers, with first stage heat exchanger 65 receiving the hottest gases of combustion. Air from the blower 24 first passes through the upper or third stage heat exchanger, then through duct 68 to the second stage heat exchanger 66, and then through the first stage heat exchanger. through ducts 1 to 69 to 65, and then burner 35
and 36 through branch conduits 31 and 32. An exhaust blower 24A is located above the third stage heat exchanger 67 and introduces a flow of hot gas from the ladle across the heat exchanger. Preferably, the first stage heat exchanger 65 operates at 2000°F.
Manufactured from magnetic materials that can withstand temperatures above. The second and third heat exchangers 66 and 67 are made from stainless steel and carbon steel, respectively, materials that cannot withstand the high temperatures that magnetic materials can withstand. For example, magnetic heat exchangers are made to withstand temperatures up to 2600°F, and stainless steel heat exchangers are made to withstand temperatures up to 1800°F, and carbon steel heat exchangers are made to withstand temperatures up to 1800°F. The vessel is constructed to withstand temperatures up to 1000°F. The temperature of the gas exiting the third stage heat exchanger is expected to be approximately 600°F. The air displaced from blower 24 is approximately 100°F.
is received in the third stage heat exchanger 67 at a temperature of
exiting the stage heat exchanger and entering the second stage heat exchanger 66 at a temperature of approximately 500°F;
It is expected to enter the first stage heat exchanger 65 at a temperature of °F. The temperature of the air as it exits the first stage heat exchanger 65 and reaches the burner is approximately 2000°F. Although specific materials from which the best heat exchangers may be made are disclosed, other materials may be used, and different sizes, types, and numbers of heat exchangers may be used, if desired. I can do it. As illustrated in FIG. 7, the ladle heater seal assembly can be reoriented from a vertical position to a horizontal position to engage the rim of an upright ladle. The sealing assembly 70 consists of a support frame 71;
A network of refractory fiber modules (not shown), similar to the modules illustrated in FIGS. 4 and 5, is supported within the horizontal support frame. The support frame includes upright threaded jack screws 72.
and 73, said exhaust gas conduit means 75 extending from an aperture (not shown) in the seal assembly 71 to the heat exchanger 74 through members 721 to 76.
and an exhaust duct 78 directs the exhaust gases away from a heat exchanger 74 away from the ladle heater. Blower 79 directs air via conduit 80 to the upper header 81 of the heat exchanger. The air is then directed downwardly through heat exchanger 74 , then lower header 82 , and branch conduits, such as conduit 84 , to a burner, such as burner 85 . The ladle heater of FIG. 7 is mounted on a carriage 86, and the carriage 86 is mounted on wheels 88 for movement along a track or the like. The reversible motor is mounted on the platform 18 and is arranged to drive the wheels of the ladle heater so that the ladle heater can be moved towards or away from the ladle. It can be moved along a trajectory 20. In other cases, the ladle heater of FIG.
Can be mounted in a stationary position. The jackpot serves as a means for biasing the sealing assembly and the rim of the ladle into a compressive relationship with respect to each other. As illustrated in FIG. 8, a controller is provided for controlling the operation of the ladle heater illustrated in FIGS. 1-4. Similar controls are provided for ladle heaters of the type illustrated in FIGS. 6 and 7. Air is supplied via air conduit means 25 and to heat exchanger 22
through the burners 35 and 36 and through the closure assembly 21 to the ladle 11. Air control valve 90 regulates the flow rate of air from blower 24 via the air conduit means. Position controller 91 adjusts the position of valve 90. The position controller 91 is actuated by a thermocouple 92 which senses the temperature of the exhaust gas traveling through the exhaust gas conduit means 38. Thus, when the temperature of the exhaust gas is higher than a predetermined value, the position controller 91 and air control valve 90 act to reduce the amount of air moving to the ladle. Fuel is supplied from the supply means to the fuel line 94 under pressure.
through the high temperature shutoff valve 95.
The flame is passed through safety shut-off solenoid valves 96 and 97 to burners 35 and 36. Thermocouple 99 senses the temperature of the exhaust gas flowing through exhaust gas conduit means 38 and regulates isolation valve 95. For example, when the temperature of the exhaust gas is too high, the valve 95
When closed, the flame from both burners 35 and 36 is extinguished. A fuel control valve 100 is also positioned in the fuel line 94. A fuel and air regulator 101 regulates the fuel valve 100 and its sensing conduit 102 communicates with the air supply conduit means 25. Sensing conduit 102 contains an air bleed line 104;
Valve 105 regulates bleed air via bleed air line 104. Position controller 106 is regulated by oxygen sensor 108 and oxygen transmitter 109. If an excessive amount of oxygen is detected in the exhaust gas conduit means 38, the oxygen I transmitter 109 causes the position controller 106 to close the valve 105, and thus the fuel air regulator 101 also causes the fuel valve 100 to close. Let it open. This provides additional fuel to burners 35 and 36, thus helping to provide sufficient fuel to complete combustion of the air-supplied oxygen to the ladle. When the sealing assembly 21 and ladle 11 are separated, the differential pressure sensor 112 senses the pressure change in the exhaust gas conduit means 38 and the differential pressure transmitter 114 actuates the position controller 115 to control the exhaust gas conduit means 38. Damper 45 is closed to prevent atmospheric air from passing through the heat exchanger. Ultraviolet sensors 118 and 119 are connected to each burner 35.
and 36, each of which in response to a flame from its burner activates its solenoid valve 120.
Alternatively, 121 may be activated to operate, thus immediately ending fuel flow to that burner. Referring now to FIG. 9, another embodiment is illustrated in which the ladle 2]2 is disposed on a support pedestal 218, the ladle being oriented 190 degrees from its normal vertical orientation. Because it is tilted, the open end 216 of the ladle is horizontally open. The ladle 212 may be a conventional ladle having a steel outer wall 214 and a refractory inner backing 215. These can be brick-shaped. Ladle heating apparatus 210 according to this embodiment of the invention includes a burner assembly 220 that also has a heat exchanger and a refractory or otherwise heat resistant inner lining 221. The heat exchanger and burner assembly 220 has an open end 222 defined by a horizontally opening port 224 in the side of the heat exchanger. The mouth 224 defines a mating aperture for receiving the open end 216 of the ladle 212 and carries a circular sealing member 225 of magnetic fiber-tight material. The material of the sealing member 225 is selected from the ladle 21 to prevent excessive leakage between the inside of the ladle and the outside air.
2 when engaged by the open ends 216 of the two. Optimal air is directed into assembly 220 along air inlet duct 228 by blower 230 . The air inlet duct 228 branches into two branches before entering the assembly 220. The volume of air transmitted by the blower 230 is adjusted by a variable orifice valve 231 disposed before the duct 228 branches. After entering the heat exchanger and burner assembly 220, the branches of the air inlet duct 228 are joined to a pair of heat exchange units 228 in the heat assembly 220, only one of which is shown in FIG. has been done. Each heat exchange unit 229 contains an air inlet passage and an exhaust outlet passage. The air inlet passageway is disposed within the assembly 220 and oriented to direct flame and combustion gases into the ladle 212 to uniformly heat the refractory lining 215 of the ladle 212. The fuel burner 233 is connected to one of a pair of fuel burners 233. The exhaust outlet passage defined within each heat exchanger unit 229 opens at 232 to the interior of rib 212 . Within the aperture 232 is a conventional temperature testing means 234 such as a thermocouple and a conventional temperature testing means 234 for sensing the amount of oxygen in the gas surrounding the test member by measuring changes in the electrical resistance of the gas. Oxygen testing means 235 is provided. An exhaust outlet passage defined within heat exchange unit 229 is also joined to an insulated exhaust duct 36 that communicates with the surrounding atmosphere, either directly or through a filter or other pollution control device. The interface between the air inlet passage and the exhaust outlet passage of the heat exchanger unit 229 must be constructed of sufficient material to withstand the heat of the combustion gases generated by the burner 233, which can be greater than 2000°F. . A suitable heat recovery device for this purpose is a tubular heat exchanger in which the single-passage cross-flow shell and internal components are constructed of porcelain material. A suitable burner for use in all embodiments of the invention uses natural gas as fuel and is 5.8xl OBTU/
"HI'TRANS" made it possible to output heat over time
The burner 233 includes a main fuel control valve 240 and an oxygen-responsive control valve 241 downstream from the main valve 240. It is supplied with natural gas via a fuel supply line 239 from a gas supply means 238 (schematically shown in Figure 11).Controls used to operate the ladle heating device 210 of the present invention A schematic diagram of the ladle heating device of the present invention having a device is shown in FIG. 11. A signal is received from the temperature checking means 234 in the temperature controller circuit 248. The construction of a controller circuit 248 for the purpose of Compare the predetermined temperature with the actual temperature of the ladle 212 and the empirical measurement of the temperature measured by the test means 234 at the aperture 232 to the exhaust outlet passage of the heat exchanger unit 229. The predetermined temperature represents the temperature of the ladle equal to the temperature at which it is desired to heat the ladle before being charged with molten metal. The temperature of the ladle can range from 1600 to 2600 degrees Fahrenheit depending on the type of molten metal disposed in the ladle. When the temperature measured by test means 234 exceeds a predetermined temperature, the controller circuit 248 starts starter 256 to operate motor 257 for a short period of time. Motor 257 is mechanically coupled to both air population valve 231 and main fuel valve 240 by coupling device 258, and Thus, valve 231 reduces the amount of air conveyed within air inlet duct 228, and valve 240 in fuel line 239 reduces the amount of fuel transmitted to burner 233. Similarly, When the temperature measured by the temperature testing means drops below a predetermined temperature, the control circuit 250 causes the valves 231 and 240 to increase the amount of air and fuel supplied to the burner by operating the motors in opposite directions. Oxygen test means 235 disposed within aperture 232 of heat exchange unit 299 sends a signal to oxygen controller circuit 249 which is responsive to fuel line 23
1 operates to regulate the oxygen response valve 241 in FIG. The oxygen controller circuit 249 is also within the ability of those skilled in the art and is commercially available from The Hague International Company under the product designation "QxSen". Oxygen Testing Means Whenever the amount of oxygen in the combustion gases, as measured by 235, rises above a predetermined valve indicating effective combustion, the controller circuit 249 causes the starter 254 to turn on the motor 255 for a short period of time. The motor 255 operates via a mechanical coupling device 259.
It is connected to valve 241 . The valve 241 is then slightly mechanically opened to somewhat increase the amount of fuel delivered along the fuel supply line 239 and mixed with air from the air inlet duct 288 and within the burner 233. be burned. Similarly, if the oxygen measured by the test means 235 indicates that the fuel and air mixture is too rich for a predetermined value of oxygen content, the control circuit 249 The valve 241 is connected to the motor 255
By operating in the opposite direction, the amount of fuel supplied to burner 233 is reduced. The heat exchanger and burner assembly 220 also contains a flame exiting from the safety fuel closure device. Ultraviolet sensor 23 is schematically illustrated in FIG.
7 is disposed within the assembly 220 in a suitable position to monitor the radiant flame emitted by the burner 233 when it is in operation, if for any reason the flame of the burner is turned off while being supplied, the lack of radiation is sensed by the ultraviolet sensor 237 and a signal is sent to the solenoid controller circuit 250.
is received from sensor 237 at . The circuit 250 is operatively coupled to a solenoid operated valve 242 in the fuel supply line 239 and closes the valve 242 in response to a flame signal from a sensor 237. The controller circuit 250 is of conventional construction and is commercially available. Assembled heat exchanger and burner assembly, blower
230 and ducts 288 and 236 are mounted on a motorized transport device 244 that runs on wheels 245 along rails 246. The assembly 220 may be moved by any conventional propulsion means (not shown) known to those skilled in the art.
It is selectively moved horizontally along rail 246. The travel of the transport device along said rail 246 is limited by end stops 247. In operation of the ladle heating device 210, the ladle 212 is first moved from its side to the platform 21 at the end of the rail 246 by any conventional means such as an overhead crane.
It is placed on 8. A conveying device 244 is first disposed in spaced relation from the end stop member 247, and then the conveying device 244
Leaning against the end stop member 247 and the sealing member 225 in the heat exchanger mouth 224, the burner assembly 2
20 engages open end 216 of ladle 212. At such times, operation of blower 230 is initiated to blow air along artificial duct 228. After passing through the inlet air passage of the heat exchange unit 229, the air is mixed with fuel from the fuel line and the mixture is ignited in the burner. The flame and combustion gas from the burner 233 are transferred to the ladle 21
Heat the refractory lining 215 of 2. The hot combustion gas is transferred from inside the ladle 212 to the heat exchanger unit 229 through the apertures 232 in the heat exchange unit 229.
escapes into the exhaust outlet passage. While passing through the heat exchanger unit 229, the hot exhaust gas transfers heat to the artificial air passing through the inlet air passage of the heat exchanger unit 229. Preheating the inlet air before mixing with fuel for combustion makes the operation of burner 233 more efficient. After passing through the exhaust outlet passage of the heat exchange unit 229,
Hot combustion gases are exhausted via an exhaust conduit. As the combustion gas passes through the oxygen testing means 235, the amount of oxygen in the combustion gas is monitored by the testing means and a signal providing such information is sent from the oxygen detection means 239 to the oxygen controller circuit 249. will be transmitted up to. If the amount of oxygen measured by the testing means 235 is higher than a predetermined value, the controller circuit 249 causes the oxygen response valve 241 to mix more fuel with the inlet air to Allows the oxygen in the inlet air to be more fully combusted. If the amount of oxygen measured by the test means is too low, the proportion of fuel and air is reduced in order to maintain optimal combustion conditions in the burner 233. The hot combustion gases also pass through temperature checking means 235 which monitor the temperature of the gases as they enter heat exchange unit I-229. In response to the measured temperature rising above a predetermined value, temperature controller circuit 248 reduces the output of burner 233 by simultaneously gradually closing blower valve 231 and main fuel valve 240 in fuel line 239. let Thus, when the burners are first lit, they can be operated at full capacity and the relatively cool ladle 12 quickly absorbs the heat of the combustion gases. When the ladle is heated, it absorbs heat less easily and the temperature checking means 234 rises. For example, an unheated 55 ton ladle costs about 110,000
Heat is initially received at a rate of 00 BTU/hour. However, eventually a stable state is reached. In this situation, only about 2000000B
TU/hour is required to maintain the high temperature of the ladle. By maintaining the temperature of the combustion gases at a predetermined value, the controller of the present invention heats the ladle 212 at the highest possible rate, while heating the ladle at any particular time. The ladle 212 also maintains energy efficiency by operating the burner 233 to provide the highest level of heat it can absorb. Thus, the intensity of the burner is gradually reduced from maximum power to minimum power during the course of a typical ladle heating operation. If, after the ladle has been heated to the temperature required to receive molten metal, the temperature of the combustion gases falls below a predetermined value during the hold period, controller circuit 248 controls valves 231 and 240 to increases the intensity of the burner, thus keeping the rib in its heated state. As will be apparent, the controller includes oxygen controller 24
The excellent coordination of fuel and air provided by 9
In response to the temperature of the combustion gases as measured by the temperature testing means 235 and regulated by the temperature controller, the burner 233 operates effectively at whatever level of intensity it assumes. When the ladle reaches the desired temperature and is required to receive a charge of molten metal, the conveying device 244 removes the heat from engagement with the open end 216 of the ladle 212. To remove exchanger 220, it is moved horizontally along rails 246. The ladle 212 is then removed from the furnace 218 and sent to a station for receiving molten metal from the furnace. Needless to say, the ladle heating device 210 also includes:
The conveying device can be fixed in place, and the conveying device is spaced apart from the fixed device in the position illustrated in FIG. The ladle 212 is disposed between the two locations. Further, the ladle heating device 210 can be oriented vertically, otherwise, to receive the ladle in an upright position. That is, a suitable operating device is required to move the devices and/or ladles into contact and away from each other. Another embodiment of the invention is shown in FIG. 10, which displays a ladle heating device 260. The ladle heating device 260 is equipped in all respects with two additional heat exchangers, a stainless steel heat exchanger 252.
The apparatus is similar to that shown in FIG. 9, except that a carbon steel heat exchanger 253 and a carbon steel heat exchanger 253 are included in the apparatus. Thus, the blower 230 directs air to the inlet air passage in the heat exchanger 253 via the artificial conduit 228a and to the artificial air passage in the heat exchanger 252 via the connecting rod 228b. , and thereafter, artificial air duct l-22
A burner 23 that engages the ladle 212 via 8C.
to a porcelain heat exchanger and burner assembly 220 containing 3. After heating the inlet gas in the assembly 220, the hot combustion gases pass through exhaust duct l-236a to the exhaust passage in carbon steel heat exchanger 253, and then into duct l-262. is emitted to the atmosphere via The three heat exchangers of the embodiment illustrated in FIG. 10 cooperate to recover as much wasted heat as possible from the combustion gases leaving the ladle 212. The porcelain heat exchanger and burner assembly 220 includes 200
Constructed from a material capable of withstanding combustion gas temperatures greater than 0° F. and transferring heat from such gases to the inlet air stream. Stainless steel heat exchangers can withstand moderate temperature exhaust gases after the heat has been extracted by the porcelain heat exchanger. Similarly, carbon steel heat exchanger 253 is effective in transferring heat from relatively low temperature exhaust gases prior to venting the gases to the atmosphere. Operation of the embodiment of the invention illustrated in FIG.
It is substantially similar to that described for the embodiment shown in the figures. Having examined the ladle heating device of the present invention in detail, it will be obvious to those skilled in the art that the principles of waste heat recovery and heating control can be applied to heat sources other than natural gas flame burners. It is possible to apply it to devices that have been used. Although the above description relates to apparatus and methods for heating ladle, it will be appreciated that a variety of other objects may be heated by the disclosed apparatus and methods. It will, of course, be obvious that the above description relates only to the preferred embodiments of the invention and that many variations and modifications may be made.
What may be done without departing from the spirit and scope of the invention as set forth in the appended claims. Embodiments of the apparatus and method for heating the ladle are shown below. (1) An apparatus for heating a ladle or the like having a chamber having an aperture and a rim around the aperture, the apparatus comprising: a sealing assembly for sealing engagement with the rim of the ladle; a plurality of refractory fiber modules mounted on a support frame in a common plane; a heat exchanger mounted adjacent to a sealing assembly; air conduit means extending through said sealing assembly for directing air through said sealing assembly and into a ladle in sealing engagement with said sealing assembly; an exhaust gas conduit means extending through the heat exchanger for directing exhaust gas from the ladle in sealing engagement with the sealing assembly through the heat exchanger and through the conduit means and the exhaust gas conduit means; a blower means for inducing a flow of air through the exhaust gas stream and for directing a flame into a ladle that supplies fuel to said air conduit and is in sealing engagement with said sealing assembly; a burner means, said sealing assembly comprising a support frame having a width greater than the rim of said ladle, each said module being compressible and capable of being compressed by said frame; The device is held in lateral compression by mutual lateral engagement with the plurality of modules positioned on the support frame in sealing engagement with the rim of the ladle. (2) said exhaust gas conduit means has a single aperture through said seal assembly, and said air conduit means has an aperture through said seal assembly on an opposite side of said exhaust gas aperture; and a burner means for supplying fuel in each air conduit aperture.
The device described in item 1). (3) the air conduit aperture and the burner means are constructed and arranged to direct a flame toward a surface of the ladle opposite the rim of the ladle and into the ladle chamber; The device according to item (2) above. (4) the sealing assembly, the exhaust gas conduit means, and the heat exchanger are configured such that flame present within the ladle chamber is substantially shielded from direct radiation to the heat exchanger; characterized by being and arranged,
The device according to item (1) above. (5) Each of said refractory fiber modules is comprised of a web of material having a web formed in a zigzag arrangement with parallel overlapping layers, said layers of each module being such that the rim of said ladle is Device according to clause (1), characterized in that it extends along its length generally towards the position of the ladle so as to be able to compress the layer. (6) the layer of the module is oriented at right angles to the next adjacent layer of the module;
The device according to item (5) above. 7. The apparatus of claim 1, further comprising means for biasing the sealing assembly and the ladle rim into compressive engagement with each other. (8) The support frames are arranged so that the support frames are fixed to each other;
(9) The heat exchanger according to paragraph (1), characterized in that it has an outer support flange surrounding the refractory fiber module for supporting the eyebar module in compression. , consisting of multiple heat exchangers 1
and wherein the air conduit means extends continuously through the heat exchanger, and the exhaust gas conduit extends in series through the heat exchanger. The device described in paragraph (1). (10) The device according to item (9), wherein the heat exchanger to which the exhaust gas is first directed is a porcelain heat exchanger. (11) The refractory fiber module of said sealing assembly is supported by a support frame on an upright surface, and means for moving said sealing assembly toward or away from the rim of the ladle. The device according to item (1) above, characterized in that it consists of: (12) refractory fiber module i of said sealed assembly;
is supported by said support frame in a substantially horizontal position and further comprises means for raising and lowering said sealing assembly towards or away from the rim of the ladle. characterized by
The device according to item (1) above. 13) A device according to claim 1, further comprising damper means in the exhaust gas conduit means for restricting the movement of gas through the exhaust gas conduit means. (14) a sealing member of a refractory fiber module disposed substantially in common plane with a force sufficient to force the rim of the truffle into the sealing member and compress the fibers of the module with which the rim engages; , engages the rim of the ladle and directs air into the ladle through the heat exchanger and through the seal, mixing the fuel and air and causing the mixture to pass through the seal and into the ladle. igniting the mixture upon entering the interior;
A method for heating a ladle, etc., comprising steps for discharging gas from the ladle via the sealing member and a heat exchanger. (15) The step of discharging the gas through the sealing member and the heat exchanger and from the rib comprises discharging the gas through a plurality of heat exchangers arranged in series.
The method according to item (14) above. (1) The step of discharging the gas from the ladle through the sealing member and the heat exchanger is to prevent the heat exchanger from direct radiation to the flame in the ladle and discharging the gas. Said No. 14J, characterized in that it consists of
The method described in section. 0'7) The above method, further comprising the steps of: preventing the discharge of gas through the heat exchanger and disengaging the rim of the ladle and the sealing member after the ladle has been heated; The method described in Section 1. (18) the step of engaging the ladle rim with the sealing member of the refractory fiber module consists essentially of closing an aperture in the ladle formed by the ladle rim; The method according to paragraph 14. a closed assembly such that each of the modules is supported by the other modules and by the support frame in compression across a common plane; and a device for heating a ladle or the like. (20) Each refractory fiber module is arranged such that the prayer seams of the block are exposed on opposite sides of the block and are arranged in overlapping zigzag folds 1"-1" in the folds of the block. consisting of a web of refractory fibers formed in a flat elongated sheet with a sheet provided thereon, said supporting frame substantially in a common plane with a fold on its side and with the next adjacent module. The combination according to item (19), characterized in that the module is supported by a fold line of each module extending at right angles to a fold line of the module. (21) For heating a ladle, etc. a movable lumbar support frame in sealing abutting relationship with the rim of the rivet; a sealing member supported by the support frame and engaged with and about the rim of the rivet; a sealing assembly comprising a layer of compressible refractory fibrous material arranged in a configuration to form a rim of the ladle, the layer of compressible refractory fibrous material being adapted to engage the rim of the ladle; Said combination, characterized in that it consists of a plankera of material folded in an accordion arrangement, with exposed filament folds. a porcelain fiber compressed material sized and shaped to mate with a sealing means defining an aperture; a porcelain heat exchanger defining an air outlet passageway for communicating with the interior of the ladle; and an air inlet passageway for directing hot combustion gases into the open end of the ladle through an aperture in the sealing means. a means for a fuel burner coupled thereto; variable fuel supply means for mixing air and fuel from the air inlet passageway and supplying the mixture to the means for the fuel burner; a blower means for moving air along an air inlet passageway, such that said sealing means forms resilient contact with the open end of said ladle and from said blower means. the air passes through the fuel supply means through the heat exchanger, travels through the fuel burner and the openings in the sealing means, and forms a flame to heat the inner surface of the ladle; Hot gas from inside the ladle returns to the heat exchanger via the sealing means and the heat exchanger, and preheats the air moving from the blower means via the heat exchanger. device for heating a ladle with an open end. (a) means for sensing the temperature of said ladle; and means responsive to said temperature sensing means for adjusting the output of said fuel burner means to maintain said ladle at a predetermined temperature; The apparatus according to paragraph (1), further comprising: (24) a porcelain heat exchange means for receiving the heat directly from the inside of the ladle; said porcelain heat exchange means (a double threaded stainless steel heat exchange means) for receiving said heat combustion forces from said stainless steel heat exchange means; carbon steel heat exchange means coupled to a stainless steel heat exchange means, the air inlet passageway passing through the carbon steel heat exchange means and through the stainless steel heat exchange means;
Apparatus according to clause (1), extending from the blower to the fuel burner means via the porcelain heat exchange means. (25) the porcelain heat exchanger has a multi-stage heat exchanger, the first stage is formed from a porcelain material for receiving the hottest gas from the ribs, and
Item 22), characterized in that at least one heat exchanger is made of another material for receiving hot gas, in succession from the porcelain heat exchanger. Device. (26) The open end of the ladle is surrounded by a heat exchanger, the heat exchanger defining an exhaust outlet passage that communicates with the interior of the ladle and the air inlet passage, and the air and fuel heating the air traveling along the air passageway by mixing the mixture with a fuel burner, directing the heated air into the ladle, and combusting the mixture in a fuel burner; heating the air traveling in the heat exchanger with hot gas traveling in the discharge outlet passage in the heat exchanger before mixing the air and the fuel; and, responsive to the amount of oxygen in the exhaust outlet, to maintain the amount of oxygen in the exhaust outlet passage at a predetermined value. A method of heating a ladle having an open end, comprising the steps of conditioning an air mixture. (27) sensing the ladle and adjusting heating of the air traveling in the air passageway by the fuel burner in response to a temperature of the ladle being other than a predetermined value; The method according to item (26), further comprising steps of maintaining a temperature of . (Se) Define an air inlet passage and a discharge outlet passage, and
a heat exchanger defining an open end at a side of the heat exchanger for receiving and enclosing the open end of the heat exchanger; a means for a combustion burner in communication with the air intake passageway for directing hot combustion gases into the ladle; a means for mixing air and fuel from the air inlet passageway and supplying the mixture to the fuel burner means; a blower means for moving air along the air inlet passageway to the burner means; means for sensing the temperature of the ladle; means responsive to the temperature sensing means to adjust the output of the fuel burner means to maintain a predetermined temperature; and means for sensing the amount of oxygen passing through the exhaust outlet passage. said oxygen sensing for adjusting the composition of said fuel and air mixture provided by said variable fuel supply means to said fuel burner means in order to maintain the amount of oxygen passing through the discharge outlet passage at a predetermined value; means for heating a ladle having an open end, the discharge outlet passageway being in communication with the interior of the ladle. (29) Said means for adjusting the amount of fuel provided to said fuel burner means in order to maintain the amount of oxygen passing through said discharge outlet passage at a predetermined value. (28), characterized in that it operates at any particular power level of said fuel burner means, as measured by said means for adjusting the power output of said fuel burner means, in order to maintain said fuel burner means at a certain value; Equipment described in Section. (g) a heat exchanger defining the air intake passageway and the exhaust outlet passageway, and further defining an open end for matingly receiving and surrounding the open end of the ladle; and the open end of the heat exchanger. a means for a combustion burner in communication with said air inlet passageway for directing hot combustion gases through said air inlet passageway; and a means for mixing air and fuel from said air inlet passageway and supplying said mixture to said fuel burner means. a blower means for moving air along the air inlet passageway to the burner means, and the exhaust outlet passageway and the air inlet passageway communicating with the interior of the ladle via the open end of the exchanger, the heat exchanger having porcelain heat exchanger means for receiving the hot combustion gases directly from the interior of the ladle. a stainless steel heat exchange means in communication with the porcelain heat exchange means for receiving the hot combustion gas from the porcelain heat exchange means; and a stainless steel heat exchange means for receiving the hot combustion gas from the stainless steel heat exchange means; carbon steel heat exchange means in communication with the stainless steel heat exchange means, the air inlet passageway being connected to the carbon steel heat exchange means through the carbon steel heat exchange means;
Then, via the stainless steel heat exchange means,
and an apparatus for heating a ladle having an open end, such as extending through said porcelain heat exchange means to said blower shell and said fuel burner means.

Claims (1)

[Claims] 1 Apparatus for heating a ladle having a lid assembly, the lid assembly comprising a support frame having a width greater than the rim of the ladle and a plurality of retractable latches interchangeably mounted on the support frame. comprising a plurality of refractory fiber modules, each of the plurality of stretchable refractory fiber modules being arranged in the support frame in a compressed zigzag or accordion shape and perpendicular to the folds of other adjacent modules. The support frame and the ladle are arranged substantially over the entire surface and maintain a constant thickness between the support frame and the ladle, resulting in direct contact between the support frame and the rim of the ladle. This prevents damage to the rim of the pan, and at the same time, when the ladle is pressed, it is depressed to form a sealed state between the ladle and the support frame, and waste gas is sent to the heat exchanger to heat the introduced air. and sufficiently protrudes from the support frame to act as a heat insulator and an insulator, blocking radiant heat and heat conduction from inside the ladle and the flame, and preventing overheating of the lid assembly and the heat exchanger. A device for heating a ladle designed to prevent heat.