US 2546538 A
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Description (OCR text may contain errors)
March 27, 1951 J. E. ERHARDTQ JR 2,546,538
APPARATUS FOR HANDLING AND BRIGHTENING METAL INVEN T012.
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APPARATUS FOR HANDLING AND BRIGHTENING METAL Filed Oct. 30, 19454 l2 SheeiS-Sheet 9 BYGWZAawMJ-U APPARATUS FOR HANDLING AND BRIGHTENING METAL Filed oct. 5o, 1945 March 27, 1951 J. E. ERHARDT, JR
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APPARATUS FOR HANDLING AND BRIGHTENING METAL Filed oct. 50,'1945 NIH mwN/MLA March 27, 1951 J. E. ERHARDT, JR 2,546,538
APPARATUS FOR HANDLING AND BRIGHTENING METAL Filed Oct. .'50, 1945 12 Sheets-Sheet l2 IN VEN TOR.
Patented Mar. 27, 1951 APPARATUS FOR HANDLING AND BRIGHTENING METAL John E. ErhardtyJr., Baltimore, Md., assignor to Crown Cork & Seal Company, Inc., Baltimore, Md., a corporation of New York Application October 30, 1945, Serial N0. 625,505
The present invention relates to apparatus for handling and brightening metal. Certain features of the invention relate to brightening fusibly coated metal, while other features involve handling metal strip, whether or not it bears a fusible coating.
Another object of the invention is to provide improved apparatus for use in brightening fusibly coated metal.
Previously developed methods and apparatus for brightening electroplated tin strip have involved heating the strip to a suicient temperature to fuse the tin and then cooling the strip so that the tin coating would be left bright. However, by the previous systems, it was necessary to maintain the strip in a non-oxidizing or non-reducing atmosphere during the brightening and in order to prevent the strip from being pitted or burned. Maintenance of a non-oxidizing or non-reducing atmosphere required the use of special fuel and extremely close regulation of conditions within the furnace. In addition, the strip was moved through several vertical runs during the brightening, the reason for so moving the strip having been to enable it to be gradually brought to a temperature which would fuse the plating. Movement of the strip through a plurality of runs necessitated a structure including a great number of elevated heavy rolls to guide the strip in the various runs, as well as the provision of suitable walls in the furnace to separate or define the chambers through which each run passed. These two factors increased the initial and maintenance cost of the furnace.
i An object of `the present invention is to provide apparatus whereby a plated strip may be brightcned in an atmosphere which includes oxygen but whereby pitting of the strip will be entirely avoided.
Another object of the invention is to provide an apparatus for brightening fusibly coated strip and whereby the brightening is accomplished during movement of the strip through a single vertical run.
Because fusing of the coating or plating and its cooling are accomplished by the present invention during a single vertical run, it is unnecessary to have the strip engaged by rollers or other guiding means whilel the coating is at a high temperature. Aside from eliminating the use of a large number of heavy rollers, marring of the tin-plate by Contact with. rollers and while the tin is soft is also avoided.
A further object of the invention is to provide an arrangement which will maintain the 4strip lin 6 Claims. (Cl. 266-3) the furnace at a low temperature if movement of the strip is stopped, and thereby protect it from being oxidized and burned through.
Another object of the invention is to provide a novel type of cooling or quenching bath for use in brightening plated metal strip, for example, tin-plate. f
Still another object of the invention is to provide a rinsing chamber structure which is useful at numerous points in processes for handling metal strip.
Most rinsing operations performed upon moving metal strip have heretofore been carried out in tanks. The use of a tank necessitates the provision of lrollers around which the strip moves in passing down into, through, and out of the tank. The rinsing chamber of the present invention is of such design that it can be positioned along a horizontal run of a strip. However, the chamber is so constructed that the washing or rinsing liquid will be confined to the chamber.
Another object of the invention is to provide a roll structure for use at submerged points in liquid containing tanks such as are provided at various points in strip handling processes.
Still another object of the invention is to provide a bearing for a submerged roller. the bearing being of such design that the liquid in which the bearingr and roll are submerged cannot reach the bearing surfaces or elements.
A still further object of the invention is to provide an apparatus for drying the strip.
The drying apparatus included in the present invention is of such design that a flow of air at a controlled temperature can be directed against the strip.
Other obiects and advantages of the invention will be apparent from the following specification and attached drawings wherein:
Figure la is a diagrammaticrelevation showing certain apparatus through which a strip is passed before the brightening operation.
Figure lb is a diagrammatic elevation of the brightening apparatus of the present invention, numerous portions of the apparatus being shown in vertical section.
Figure 2 is a transverse section of a. rinsing chamber, the view being taken on the line 2-2 of Figure 5,
Figure 3 is a sectional View on the line 3-3 of Figure 2 as Well as the line 3 3 of Figure 5.
Figure i is an enlarged sectional view of a Chamber structure.
Figure 5 is an elevation of the rinsing chamber, the view looking toward the top of the views shown in Figures 2 and 3.
Figure 6 is an end elevation of the rinsing chamber, the view being taken looking toward Figure 3 from the left.
Figurey '7 is a diagrammatic view illustrating the arrangement of the heating burners in the brightening furnace. More particularly, the lefthand wall of Figure 7 shows the heating elements on the left-hand wall of Figure 8 while the righthand portion of Figure 7 shows the heating elements on the right-hand portion of Figure 8`.
Figure 8 is a vertical sectional view of the fusing chamber portion of the brightening furnace and showing the fuel supply connections to the burners.
Figure 9 is an enlarged sectional detail of a burner hose connection such as used in the' assembly of Figure 8.
Figure 10 is a transverse vertical sectional View of av quenching tank, the section being taken on the line lil-l0 of Figure 11.
Figure 11 is a vertical sectional View on the line H-ll of Figure 10.
Figure 12 illustrates the strip cooling device, the view being a vertical section taken on the line |2--l2 of Figure 13.
Figure 13 is a top plan view of the strip cooling mechanism.
Figure 14 is a vertical sectional view on the line llilll of Figure 13.
Figure 15 is a longitudinal sectional View showing a roll structure and a bearing therefor, the view being taken on the line l5-l5 of Figure 16.
Figure 15a shows an enlarged detail of the Figure 15 structure.
Figure 16 is a top plan view of the roll structure of Figure 15.-
Figure 1'7 is a transverse sectional view on the line IT-I'l of Figure 16.
Figure 18 is a side elevation of the blower duct used with the furnace and connected to the strip drier.
Figure 19 is a sectional view on the line l9--l 9 of Figure 18, the view showing one drier element or Vbox in elevation;
Figure 20 shows the structure of Figure 18 in top plan.
Figure 21 is a detail section taken on the line 2l-2I of Figure 19.
Figure 22 is another showing of the duct, blower and drier assembly, this view being taken look-A ing toward Figure 18 from the right of the latter figure, and
Figure 23 is a sectional view of the drier taken on the line 23-23 of Figure 22.
The principal elements of the present apparatus and their general operation are as follows: Referring to Figure la a strip of metal S, ordinarily a steel strip of a width of approximately thirty inches, is passed through a picking tank 25, then between pinch rolls 26, into a rinse tank 21, and then through the apparatus 23 which will electro-plate a tin coating upon strip S to 'produce the plated strip S. The pickling, rinsing and electro-plating operations just referred 'to are described in the application of William B. Cooper and Charles E. Glock for Apparatus and Method of Coating, led December 24, 1941, Serial No. 424,402 now abandoned. The plated strip S then moves over a roll 29 and through a rinse chamber 30 illustrated in detail in Figures '2 to 6. In the rinse chamber the strip is subjected to a spray of water or other suitable wash liquid, the chamber 30 being of such construction that no liquid can be jetted therefrom. In addition, the rinse chamber 30 includes rubber-covered rolls 32 which remove all surplus water or rinsing liquid from the strip before the latter leaves the rinse chamber.
The strip S then moves upwardly (Figure 1b) to a roll 33' positioned above the brightening furnace 34 and passes down about roll 33 for movement in a vertical run through the furnace. A strip cooling device 35 shown in detail in Figures 12 to 14 is positioned immediately below roll 33. The purpose of device 35 is to enable water to be jetted upon the strip in the event that movement of the strip should be stopped. The water thus jetted upon the strip will flow downwardly along the vertical run to prevent the portion of the strip within the furnace 34 from being burned and thereby disintegrated by the oxidizing action which will occur when the strip is stopped while the furnace is at normal operating temperature.
The brightening furnace 34 is illustrated in detail in Figures 7 to 9, with an additional showing of its lower end structure appearing in Figures 10 and 1l. Generally speaking, the brightening furnace 34 comprises a tower open to atmosphere only at its upper end and with burners positioned adjacent its lower end so that rising products of combustion will pre-heat the strip S as it moves downwardly through the upper portion of the furnace. The lower end of the furnace 34 has a water-sealed connection with a quench tank 36 illustrated in detail in Figures 10 and 11. During its movement past the burners of the brightening furnace 34, the tin coating on the steel strip will be fused so that it will iiow. While the coating is in this condition, the strip moves into the quench tank 36 and the coating is thereby instantly hardened so that the strip will be brightened, i. e., all small protuberances upon or other roughness of the surface of the strip will be smoothed out and a bright mirror-like finish will be imparted to the strip.
A roller 3'! of the detailed structure best shown in Figures l5 to 17 is journalled at the bottom of the quench tank 36, the roller 31 being rubbercov-ered and provided with a bearing structure which includes means to prevent the quenching liquid reaching the bearing surfaces. After movement about roller 31, the strip moves upwardly and between rolls included in a wringer roll assembly 38 which removes surplus quenching liquid from the strip. After movement through a short horizontal run, the strip moves in vertical runs through a chemical treatment tank 39. During movement through the tank 39, the strip will be subjected to known treatments whereby its surface will be given an adequate ainity for lacquer or other coatings. Tank 39 preferably comprises two compartments 40 and fil. The strip moves through the compartment di) in vertical loops, this compartment being filled with the treating solution. Compartment 4l is ordinarily empty and is used to store the treating solution when the treating solution compartment 4D is being cleaned. A pump, as shown, may be included in the tank structure to enable the treating solution to be moved from one compartment to the other.
After the strip S leaves the chemical treatment tank 39, it will be passed through wringer rolls 42 which will remove excess treating liquid from the strip. Then, in a, horizontal run, the strip passes through rinse chamber 30a which is identical in structure with the previously described rinse chamber 30. Beyond rinse chamber 30a the strip moves in a vertical run through a drier 43 designed to remove all moisture from the strip.
The drier 43 and the duct and blower system associated therewith are illustrated iny detail in Figures 19 to 23. Generally speaking, the drier 43 comprises two outlet boxes 44v and 45, one positioned on each side of the strip as shown in Figures 1b and 23. Each outlet box is provided with outlet openings through which air of the proper temperature is directed against the strip as it moves through the drier. The outlet boxes are supplied with air of the desired temperature by a blower and duct system shown in Figures 18, 20 and 22. The air is forced through the ducts by the blower 46 which also serves to create a forced draft in the upper portion of the brightening furnace 34 through a duct 4l. The temperatureV of the air directed against the strip S by the drier 43 may be controlled by a heater 48 mounted in the duct system between blower 46 and drier 43.
After the strip S has been dried, it moves through a series of main pinch rolls 56. As is shown in my divisional application S. N. 180,683, iiled August 21, 1950, for Apparatus for Handling Metal Strips, the lower pinch roll 5I of the series 56 is driven by a motor. The pinch roll structure 50 imparts the necessary drive and tension to move the strip through the elements shown in Figures la and 1b and which are in advance of the rolls 50 and to the rear of the auxiliary pinch rolls 26 of Figure la. The auxiliary pinch rolls 26 diagrammatically illustrated in Figure la exert tension upon the strip to move it through the pickling tank and the usual elements in advance of tank 25. In short, the strip is driven by the auxiliary pinch rolls 26 while it is moving through the infeed portion of the electrolytic coating apparatus and the portion of the strip moving through the remainder of the electrolytic apparatus and through the apparatus of Figure 1 is driven by the main pinch rolls 50. The motor 54 for the auxiliary pinch rolls is electrically connected with the motor 52 of the main pinch rolls 50 as schematically shown in Figure lb so that both sets of pinch rolls will be driven in synchronism. The provision of main pinch rolls at a point in the brightening apparatus which is beyond all of the strip treating elements is highly advantageous because it insures that the strip will be under uniform tension during its movement through all 'of these elements.
As is shown in Figure lb, the strip S moves from the main pinch rolls 56 directly to the outlet looper 55. Looper 55 includes an upper 'vertically movable sheave carrying platform 56. As best shown in Figure 1b, the platform 56 is connected by suitable cables passing through a main sheave and auxiliary sheaves to counterweights 51. In order to control the anti-crash braking system, strip breakage detectors 58 and 59 (Figure lb) are provided immediately in advance of the drier 43 and immediately beyond the looper 55, respectively. These detectors are electrically connected with the brake. Location of these detectors at the points` specified, i.l e., the points of greatest tension, insures that the anti-crash devices will be highly responsive to any breakage.
Immediately beyond the second detector 59 the strip S moves through a pair of rolls designated by the numeral 6l) and by means of which the strip may be gripped. From the roll 60 the strip is directed to coiling drum 6| upon which the strip may be wound into a coil. Shearing means, not shown, will be positioned between the tension rolls 60 and the coiling drum 6l. In accordance with usual practice, when a full coil has built up on the coiling drumH 6l, the tension rolls 6i] will be held against movement so that the strip will be clamped between these rolls. The strip will then be sheared between the tension rolls and the coiling drum and the full coil removed from the coiling drum. During this interval of time, the looper 55 will take up the supply of strip which is moving through the apparatus. 'Ihe sheared end of the strip will then be connected to the coiling apparatus and the tension rolls 60 released for normal operation and during which operation the looper will gradually feed out the strip which has accumulated thereon during the stoppage.
The detailed construction and operation of each element of the apparatus is hereinafter disclosed.
Rinsmg chamber The rinsing chambers 30 and 30a are identical in construction, and therefore, only the detail construction of the chamber 36 will be described. Figures 2 to 6, inclusive, illustrate the rinsing chamber 30, which is of rectangular box-like shape including a bottom wall 16, a top wall 1l, side walls 'l2 and end walls 13 and 14, respectively.U It is to be understood that the designation of these walls as top, side or end walls is for the purpose of the present description because, as is hereinafter explained, the rinsing chamber 30 need not be positioned in a horizontal plane and with the various Walls in the positions shown in Figure lb.
The various walls of the rinsing chamber 30 are rigidly secured together except that the top wall 1 l is pivoted as indicated at 'Ha to the end wall '54, thereby making the interior of the chamber accessible. The free end of the top wall 1| is secured in closed position by means of the fastening devices 1lb.
The strip S moves into the chamber through a slot T5 provided in the end wall 13 as best shown in Figure 3. The strip then passes between rolls 32 of a pair 16, then between spray nozzles 'E1 positioned inwardly cf the roll pair "i6, and then moves between a roll pair 78. Immediately beyond the last mentioned pair of rolls the strip moves out of the chamber through a slot 'I9 formed in the end wall 14.
As best shown in Figure 6, the slot I5 in the end wall 13 is of slight width but is of a length Which closely approximates the width of the strip S. As best shown in Fig. 3, anges inwardly from wall 13 along both of the long edges of the slot. These anges converge to a point adjacent the roll pair E6 and so that their free ends will be close to the strip. The ends of the flanges are closed by walls 86. The slot 19 in the opposite end wall 14 of the chamber is provided with flanges 86a which converge, toward the interior of the chamber and near the roll pair T8 in a manner identical to that described in connection with the anges 86.
As best shown in Figure 3, the side walls 'l2 are provided with slide-ways 82, one slide-way being provided at each end of each wall 12 so that the chamber includes a pair of opposed slideways at each end thereof. A plate 83 and a plate 84 are mounted inveach slide-way, the plates 84 being the lowermost plates in Figure 3. The plates 8e are secured against movement in the slide-ways but the plates 83 are slidable longitudinally of the slide-ways, being held in the adjusted position by means of adjusting bolts 85 which extend to the exterior of the wall 1| and are threaded in bosses 86 on that Wall. Each plate 83 and 84 has a bearing 81 mounted therein for one of the rolls 32 of the pairs 16 or 11. It will be observed that by this construction the position of each uppermost roll 32 with respect to its opposed lower roll may be adjusted so that rolls will closely contact with the strip. Suitable piping such as generally indicated by the numeral 88 may be provided to enable the various bearings 81 to be supplied with lubricant from a lubricant fitting 89 mounted in the top wall 1i of the chamber.
Water or other rinsing liquid may be supplied to the rinsing chamber through a manifold 90 (Figures and 6) connected to a suitable source of supply. Manifold 90 has branches 9| secured to it which extend toward the lower and upper walls 10 and 1| and, as best shown in Figures 2 and 3, these pipes extend to upper and lower headers 82 and 93, respectively, which extend parallel to the rolls. It will be observed from Figure 3 that a number of headers are provided on each side of the strip. Each header is fitted with a number of nozzles 11, the nozzles including deflectors 95 which serve to spread the water moving from the nozzles as shown in Figure 2 and also direct the jet toward the sheet along a line which is at an obtuse angle with respect to the sheet as best shown in Figure 3. Figure 3 indicates how the sheet moves through the chamber 80 from the left to the right of that gure and it will be observed that the jets face toward the approaching sheet.
The end walls 13 and 14 and the bottom wall 10 are provided with threaded outlets 9B, 99 and |00, respectively. When the chamber is used in connection with the strip moving in a horizontal run, the outlet |00 will be tted with a water outlet line |0| because the outlet |00 will then be the lowermost outlet. At such time the outlets 98 and 99 will be closed with suitable plugs. However, if the casing is mounted adjacent a vertical run, either of the outlets 98 or 99 may have an outlet line connected thereto, depending on which outlet is lowermost. In such case the other end wall outlet and the outlet |00 will be plugged.
The rinsing chamber 30 described above insures that a rapidly moving strip may be thoroughly rinsed and without the necessity of any large tank structure. The rolls 32 positioned adjacent the inlet slot 15 cooperate with the converging ange structure of that slot to prevent Water from moving outwardly through the slot. The rolls 82 positioned adjacent the outlet slot 19 have a similar cooperation with the anges of that slot. In addition, by having the rolls 32 in close engagement with the strip, excess water is remove-d from the strip by the rolls.
The rinse chamber structure included in the present invention is highly advantageous in a strip line because it enables a strip to be rinsed or washed at any point in the line and without the necessity of providing a tank or the rolls necessary to guide a strip downwardly into a tank, and then upwardly, and then over the edge of the tank.
As has been indicated above, the chamber 30 can be positioned in any plane. In any posi- 8 tion, the rolls and converging flanges will prevent liquid from reaching the exterior of the chamber. It will also be understood that if the strip is to move in a direction opposite to that shown in Figure 3, the nozzles may be turned 180 to cause water to impinge upon the advancing sheet.
Brightening furnace As best shown in Figure 1b, the brightening furnace 34 is in the form of an enclosed tower with vertical beams |05 extending above it to support the journals for the roll 33. The furnace includes an outer casing formed of metal plates and designated by the numeral |08. Two opposite walls |01 and |08 are somewhat wider than the width of the strip to be passed through the furnace. The remaining walls |09 and ||0 lie opposite the edges of the strip and therefore are of less width than the walls |01 and |08. At the extreme upper end of the enclosed portion, a pair of spaced ducts and ||2 communicate with the furnace to withdraw the products of combustion therefrom as hereinafter explained. Above these ducts, the furnace is closed by plates ||2a adjustable with respect to each other to define a slot ||2b (Figure 20) through which the strip enters the furnace.
From a point downwardly of the ducts and ||2, the furnace is lined with rebrick ||3. At a point approximately three-fifths of the distance from the ducts to the lower end of the furnace, the rebrick lining extends inwardly to form a ledge as indicated at H4, and thereby reduce the furnace bore at this point. Below this ledge, the wider walls |01 and |58 have burner nozzles ||5 extending therethrough and tted between rebrick elements as best shown in Figures 8 and 10. As best shown in Figure 10 the burner nozzles ||5 are arranged in horizontal rows in the walls |01 and |08. However, as indicated in Figure 11 and also in Figure 7, the horizontal rows of nozzles of the respective walls are vertically staggered with respect to each other. Each nozzle |5 has a flexible tube or line ||6 extending therefrom to a manifold, a manifold being provided for each row of nozzles. As shown in Figure 8, a manifold ||1 for a horizontal row ||5a of burners in the wall |01 is connected by a line |8 to the manifold H9 for the substantially opposite ro-w ||5b of burners in the other wall |08 and a valve |20 (Figure 1) may be provided to control the connected pair of manifolds. The valve |20 is mounted in a branch line |2| which connects the pairs of manifolds to the main fuel supply line |22.
It will be observed that by connecting the opposed manifolds in pairs and providing a valve |20 for each pair, the burners in the furnace can be separately controlled in horizontally extending banks.
The valves |20 are hand-operated valves for emergency shut-off and flow of fuel ordinarily will be controlled by a solenoid operated valve |20 (Figure 1b) positioned adjacent each valve |20. For the purpose of clarity, Figure l shows valves only for every other pair of manifolds.
The fuel supplied to the burner nozzles is a "premixed gaseous fuel. However, for the reasons hereinafter set forth, the fuel need not be non-oxidizing.
The operation of the brightening furnace in connection with the movement of a strip therethrough is as follows: Ihe strip S moves downwardly over the roll 33 at a speed ranging from 200 to 550 feet per minute, depending upon the width and thickness of the strip and the thickness of its coating, a narrower and thinner strip, with a thin coating, movingA at the higher range. With a thirty inch wide strip, having a thickness of .009 of an inch, and with a onehalf pound per base-box coating, the strip would move at approximately 380 feet per minute. With the burners in operation, the temperature in the lower or fusing portion |23 of the furnace, i. e., the portion below ledge Ht, will range from 2300o F. to 2500 F. However, the rapid movement of the strip will cause the latter to be heated to from 450 to 590 F. The above temperature gures are given for the case of tin coated steel plate, tin having a fusing temperature of 449.5" F. It will be observed that the tin coating will be fused by passage of the strip through the burner equipped lower zone o1' portion |23 of the furnace. rlhe downwardly moving strip and inwardly extending ledge or baffle Ilfi slightly retard upward movement of the gases of combustion from the burners and so that an area of high temperature will be provided in the portion |23 beneath ledge llt. However, the gases of combustion will rise past the ledge ||li and into the upper portion or zone |211 to maintain a temperature there which will be somewhat lower than that in the fusing zone |23 so that the tin may not become molten while movingthrough zone |23. Nevertheless, the tin will be pre-heated in the zone |24 to a suicient extent that the tin coating will be only slightly below fusing temperature by the time that it enters the fusing zone |23. The major portion of the products of combustion will be drawn off through the ducts and H2 as hereinafter explained.
As is illustrated in Figures and ll, the extreme lower end of the furnace is closed by a horizontally extending wall |26 including an opening |27 therein through which the strip may move from the furnace. However, as is subsequently described, this end of the furnace is sealed against the entrance ofV atmospheric air by the quench tank 36.
It will be noted that the brightening furnace 34 is of such design that no roll contacts with the strip during its descent through the furnace. Also, no rolls are mounted in the hot atmosphere of the furnace, roll 33 being well above the furnace. Therefore, when any area of the strip is moving over the upper roll 33, that strip area is at normal temperature so that its coating of tin or other fusible material is still hard. During the remainder of its downward travel, the strip has no contact with any guiding means. Therefore, when the tin becomes heated to a fusing temperature, it will fuse to a smoothly flowing coating without any possibility of being marred or scratched in any way before` it is again hardened by quenching as subsequently explained.
In a furnace designed for movement of a strip therethrough at a speed of the range stated above, the fusing zone |23 would be approximately six feet long, pre-heating zone |24, in-
Strip cooling device Thestrip cooling device 35 is best illustrated in Figures l2 to 14 although Figure 1b shows its relationship to the upper end of the furnace 34 and the roll 33. As best shown in Figure l2, the strip cooling device 35 comprises apertured pipes |3i and |3| which extend horizontally and parallel with the opposite faces of the strip S. Each of the pipes |30 and |3| has a tray or plate |32 and |33, respectively, secured thereto with the plates inclined downwardly and to- .ward the strip S. The lateral ends of the plates have walls |34 extending upwardly therefrom. The pipes |36 and |3| are supported -on brackets 35 secured to the vertical beams |95 and each pipe is connected at one end by a fitting |36 to a line |3'E which leads to a pressure regulator E33. A solenoid actuated valve |39 is connected in the supply line ll which delivers water to the pressure regulator |38 from which it flows to the horizontal pipes |30 and I3I. The pipes i3d and |3| have ports Ml spaced along the same, the ports preferably being drilled on axes which extend substantially parallel with the plates or trays |32 and |33, respectively, and facing the free ends of the trays. A deflector plate |42 is secured to each of the ported pipes |33 and |3| `as illustrated in Figure 12, i. e., to deflect the jets from the pipes downwardly for flow upon` the trays |32 and |33 and then upon the strip S.
The operation of the strip cooling device is as follows: 1f it becomes necessary to stop the movement of the strip S for any reason and while the furnace is at normal Yoperating temperature, the solenoid valves |20 of the burner fuel supply lines will immediately be operated tot extinguish the burners ||5. However, the temperature of approximately 2300o F. and the oxidizing atmosphere in the fusing zone |23 would almost immediately burn and destroy the length of strip S which is in that zone. Operation of solenoid controlled valve |39 in the water supply line |40 will result in a flow of water fromthe apertured pipes |30 and |3| which will cause both sides of the strip to be completely covered and thereby protected by a sheet of water from a pointv just below the strip cooling device 35 to the surface of the liquid in the quench tank 36. When water first reaches the portion of the strip in the fusing zone |23, it will be converted to steam by the high temperature, but the steam will protect the strip and its protection eventually will be augmented by the continuously descending sheet of water. When the temperature of the furnace drops to a point below oxidizing temperature, the flow of water may be out off.
The provision of the strip cooling device 35 eliminates the necessity of maintaining nonoxidizing atmosphere in the furnace. It is found that with a furnace supplied with a gas which results in oxidizing products of combustion, a tincoated strip will completely burn and disintegrate within a few seconds if its movement through the furnace is stopped while the furnace is at the operating temperature indicated above. However, provision of the strip cooling device prevents this burning and disintegration because even though the water owing down the strip may be converted to steam, it adequately blankets the strip at such a point against the surrounding temperature. For that reason, the provision of the strip cooling device 35 eliminates one of the principal reasons for maintaining a non-oxidizing atmosphere in a brightening furnace. Because the cooling water moves down along the strip into the quench tank from which it can overflow through an overflow arrangement hereinafter described, no water will come into contact with the furnace structure.
Quench tank The quench tank 36 is best illustrated in Figures 10 and 11 and is of open-topped formation including a bottom wall and four lside walls. Tank 36 is positioned directly beneath the lower end of the furnace 34 and a substantially rectangular duct |50 extends downwardly from the bottom wall |26 of the furnace to a point below the upper edge of tank 36. The duct |50 includes two long walls which extend parallel to the long walls |01 and |08 of the furnace 34 and are somewhat longer than the width of the strip. The two remaining walls of the duct are sufficiently far apart to permit the strip to readily move through the duct. The lower end of the duct |50 has a trough |52 secured thereto, the trough preferably being rectangular in radial cross section but being open on its upper and inner quarter so that water or other quenching liquid in the tank 36 may flow over the inner edge |53 of the trough. An outlet pipe |54 extends downwardly from the trough |52 at one point in the length of the latter.
The roll 31 journaled in the lower portion of the quench tank is so positioned that the strip S may move in a straight vertical run from the roller 33 down to the roller 31 as best shown in Figure 1b, the strip passing about roll 31 and moving up out of the quench tank along a run which may be at an angle to the vertical. Quenching liquid, preferably water, is supplied to the quench tank through two delivery pipes |55 which open to the tank through the side wall |56 whichis furthest from the trough |52 as shown in Figure 1l. The diagrammatic showing of these pipes |55 included in Figure illustrates their position with respect to the strip roll 31; that is, the inlets are below the strip roll 31 and are beyond the edges of the strip moving about that roll.
The temperature of the quenching liquid in the quench tank 36 is controlled as follows: In handling tin-plate it is desirable that the quenching liquid have a temperature slightly below 200 F. at the point at which the molten tin coating iirst contacts with the liquid, i. e., in the portion of the liquid bounded by the trough |52. If the temperature of the liquid in this area rises above 200 F., the water will become agitated and splash upon the descending strip so that quench marks will appear on the strip. Such marks detract from the desired bright finish.
When the quench tank 36 is to be placed in operation, the water in the tank may be brought to such a temperature that the heated strip will not raise its temperature above 200 F. This heating is obtained by means o'f va steam coil |56a immersed in the tank, the ow of steam being controlled by a valve controlled by a thermocouple 15617v responsive to the temperature of the quenching liquid. When the movement of heated tin-plate into the tank begins, the incoming water will be supplied at a rate determined by the thermocouple, the latter being so adjusted that the water within the area bounded by trough |52 will not have a temperature in excess of 200 F. In the area immediately bounded by the trough |52, the descending strip at a temperature of between 450 F. and 500 F. will raise the water in that area to 200 F. but this water will immediately ow into the vtrough |52 and leave the tank so that the temperature there will never exceed 200 F.
The construction of the outlet trough |52 is highly desirable because it withdraws water at the point at which the water reaches its highest temperature. In addition, because the trough |52 is located at the lower end of the duct |50, the trough forms a seal about the lower end of the furnace 34 and prevents any upv/ard drafts from entering the furnace. Air entering the furnace at this point would reduce the furnace temperature.
Submerged roll bearing structure The detailed construction of the bearing for the submerged roll 31 is illustrated in Figures 15 to 17. Referring to Figure 15, roll 31 includes a stub shaft |60 at each end thereof. The purpose of the present bearing structure is to prevent the liquid surrounding the bearing' from reaching the interior of the bearing.
The support |6| for each bearing is secured to a bracket |62 secured to a side wall of the tank 3, the support being held to the brackets by threaded studs and spaced nuts as indicated at |63 in Figure 17. The support i0! is of two-piece form so that it readily can be disassembled. A housing |04 of sleeve-like form is positioned within the support and the inner surface |65 of the support |6| is spherically concave to receive a central enlargement |06 on the housing, the enlargement being spherically convex. This arrangement eliminates the necessity of having the supports |6| at each end of the roll 31 exactly7 in alignment. However, a pair of diametrically opposite pins |61 may be provided in the support |6| to loosely engage sockets in the housing |64 and thereby limit movement of the housing in the support.
IThe inner end |63 of the housing |04 extends to a point closely adjacent the end of the roll 31 and a pair oi sealing members |39 are positioned within this end of the housing to bear upon the surface of the stub shaft |60 which is preferably enlarged at this point as indicated at |60a.
As shown in Figure 15a, each sealing member |69 includes a ring |10 of compressible and resil'ient material, the ring being enclosed in an outer metal collar |1| and an inner metal collar |12, the outer collar |1| including an outer wall |13 and a side wall |111. The other edge of wall |13 is turned inwardly as indicated at |15 and the inner collar |12 is positioned within the short iiange thus provided. Inner collar |12 carries a short flange |16 at its inner edge and this flange lies against the outer wall |11 of a groove |18 in one side of ring |10 to thereby x the position of the body of the ring |10 with respect to the periphery of the stub shaft or supported element |60. The portion of the ring |10 inwardly of the groove wall |11 is in the form of a tongue |19. including a surface |60 'adapted to bear on the periphery of the shaft |00 and the groove |18 provides an annular space which lies outwardly of this tongue.
As best shown in Figure l5, the two sealing members |69 are so positioned that they will be spaced apart and their' grooves |16 will face each other. An air pressure line |8| is threaded in the housing it-between the two sealing members so that air pressure flowing through the pipe |8| from a suitable source will move into the grooves |18 and thereby act upon the outer surfaces |82 of the tongues |19 to hold the inner surface |80 of those tongues in close engagement with the periphery of stub shaft 60.
A roller bearing assembly designated by the numeral |86 and including inner and outer raceways is positioned in the housing 54 outwardly of the sealing members |89 and a thrust bearing |85 is positioned in the housing between the bearing |85 and a cap |37 threaded upon the outer end of the housing. A lubricant line |88 opens to the cap and the housing and the bearings are suitably grooved so that the lubricant may move to the same. The bearing assemblies |85 and |86 support the stub shaft or supported element |60.
'Ihe action of the sealing members |59 is as follows: Air is supplied through the tube |8| under a pressure greater than the head of the liquid in the quench tank 35, this pressure holding the inner surfaces |82 of the tongues Ile in sealed contact with the periphery of each stub shaft |60. As a result, the liquid in the tank 35 cannot move past the sealing members |52 to reach the bearing assemblies. The fact that the outer end of the housing assembly |62 is sealed by the .screw cap will prevent liquid from entering the housing at that point.
Strip drier The strip S moves from the quench tank 35 along an inclined run |95 as best shown in Figures lb and 11. In order to remove the maximum amount of water or other quenching liquid from the strip at this point, a wringer roll assembly 33 is secured to the upper edge of the quench tank as best shown in Figure 11. Referring to Figure lb, the run |95 extends to a roller |55 about which the strip moves to pass in a horizontal run and over a roller |92 beyond which the strip moves downwardly into liquid contained in a compartment 45 of a tank 39. The strip movesabout a number of vertically spaced rolls associated with the tank compartment 4|) so that it will pass through the liquid in the compartment in vertical runs. The submerged rolls provided in the compartment 45 may be mounted in the same manner as the submerged roller 3l illustrated in Figures 15 to 17 so that the liquid in compartment 45.y will be excluded from the bearings.
The liquid in the compartment 4|) is of such nature that it will give the strip a proper affinity for lacquer or other coating or decoration.
Tank 39 preferably includes a second and storage compartment 4! which is normally empty. When it is necessary to clean the treating compartment 45, the treating liquid may be moved from compartment 4l) to the storage compartment 4| by operation of a pump |98.
On leaving the compartment 40, the strip S moves through wringer rolls 42 which remove surplus treating liquid from the strip. The strip then moves about a roller 255 to pass, in a horizontal run, through a rinse chamber 30a, which is identical in construction with the rinse chamber 35. The rinse chamber 33a will remove all treating liquid from the strip and also all surplus water or whatever other liquid is used to wash the strip in chamber 55a. However, it is necessary at this point that the strip be thoroughly dried and, for that purpose, the strip moves from rinse chamber 30a, about a roller 206 and between outlet boxes 44 and 45 included in a drier 43.
As best shown in Figures 19, 21 and 23, each of the outlet boxes 44 and 45 includes a body portion which is of rectangular and box-like form to include an inner wall 2|5, an outer wall 2|6, and three edge walls 2|'l which join the inner and outer walls. Each inner Wall 2 l 5 is provided with'vertically spaced slots 220 (Figure 19) of a length approximating the width of the strip and ang-led members 22| best shown in Figure 21 are positioned on the outer face of the inner wall 2 5 immediately adjacent the edges of the slots 220. Each angled member 22| includes a portion 222 which lies upon the wall 2|5, the Walls 223 of the two members 22| associated with each slot diverging toward their outer ends so as to direct air in a V-shaped stream against the opposite surface ,of the strip S.
The boxes are supplied with air under pressure h by the following system: A blower 4B driven by a suitable motor 224 is positioned adjacent the brightening furnace 34 and has its outlet 225 (Figure 22) communicating with a duct 223 leading to a nozzle 222 positioned at the lower end of the furnace stack 228 so that air blown through the nozzle will move upwardly in the stack 223 to create a strong draft therein. The outlet ducts and ||2 at the upper end of the furnace 34 open to the stack 228 so that products of combustion will be withdrawn from the furnace by the action of the blower 45. The outlet ducts Il! and ||2 may be provided with clampers 23o to regulate the Volume of combustion gases moving therethrough so that the gases will not be drawn too rapidly from the furnace.
A duct 235 (Figure 22) also leads from the outlet 225 of the blower 46 and opens to a duct 235 includingan outlet or waste 2360, leading to the exterior of the plant. A damper 237 is positioned in the outlet 225 between the ducts 235 and 226. By swinging this damper to the right or left as viewed in Figure 22, the volume of air delivered from blower 46 may be divided between the stack nozzle Z and the duct 235 as conditions require.
Duct 235 also communicates with a duct 23 leading to a steam-operated heater 18 and a damper 24B at the junction of the ducts 236 and 238 enables some or all of the air directed through duct 236 to move into the duct 238 and then to heater 48. A duct 24| leads from the outlet of heater 48, the duct 24| diverging into two branches 242 which respectively open tothe outlet boxes 44 and 45 of drier 43 as shown in Figures 19 and 20.
In operation, referring to Figure 22, the blower will supply air to both of the ducts 226 and 235, the proportion delivered to each being determined by the damper 231. If conditions are such that drier 43 does not require all of the air blown through duct 235, damper 240 may be positioned to divert the excess through waste duct 235er. The remainder will pass through heater 48 and thence through duct 24| to the drier. If movement of the strip S is stopped and if blower 45 is still being operated at such time, damper 223 may be operated to direct all air supplied to duct 235 to waste duct 23511.
It will be observed that the duct system just described and the action of drier 43 will enable the strip to be thoroughly dried without the necessity of a blower other than the stack blower 46. Also, the construction of the vslotted port outlet boxes 44 and 45 enables the strip to be dried without movement through a closed chamber or about ani7 rolls.
The terminology used in the specification is for the purpose of description and not of limitation, the scope of the invention being indicated in the claims.
.1. In a strip handling apparatus, a vertically extending furnace Structure, means to move a strip downwardly in a vertical run through said structure, means adjacent the lower .portion of the structure to heat the strip, and means adjacent the upper portion of the structure to cw a 'cooiing liquid upon the run withinthe structure.
2. In a strip handling apparatus, means to move a strip of metal in a substantially vertical run, means to apply heat to the strip at a point on said run, and means above said last-named means to direct Ycooling liquid upon the -strip so that the liquid will iow downwardly and substantia'lly :cover the strip.
3. In combination, a liquidecontaining tank, i
means above the tank to heat 'a metal strip, means to guide the strip in a run through said heating means, downwardly into the liquid in the tank and upwardly out of the liquid, a horizontally disposed endless trough 'surrounding the downward run 'of the strip at a 'p'oi'nt adjacent the to'p of the tank, a liquid overflow line communicating with said trough, and liquid inlet means adjacent the bottom of .the tank, said inlet means being positioned on the opposite side of said upward and outward run from said downward run.
4. In a strip brightening apparatus, a furnace including heating elements, means to -move the strip through said 'furnace means to apply cooling liquid to the portion of the strip in the furnace, and means lresponsive to strip breakage to render said strip moving means and the furnace heating elements inoperative and cause said liquid applying means to apply liquid to the strip.
5. A strip handling 'apparatus of the character defined in claim 1 wherein the means lto iiow 'a cooling liquid upon the strip includes a tray 'inclined downwardly toward the run.
16 6. A strip handling apparatus of the character defined in claim 2 wherein the means to ydirect cooling liquid upon the strip includes a tray infclined downwardly toward the run.
JOHN ERHARDT, JR.
' REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number I Name D ate Re. 20,673 Meyers Mar. 15, "1938 496,208 Procunier Apr. 25, 1893 1,798,718 Brown Mai-.81, 1931 1,811,522 shover et a1 June 23, 1931 1,890,065 Meehan Dec. '6, 1932 1,945,776 Hait Feb. 6, `10934 1,991,817 vNachtman Feb. 1'9, 1'9'3'5 1,998,192 Haswell Apr. 1'6, 1935 v2,086,503 Russell Apr. 7, 1936 2,141,108 HOak De'C. 20, 1938 2,141,382 Ferm Dec. 27, 1938 2,215,080 Ness Sept. 17, 1940 2,240,265 Nachtman Apr. 29, 1941 2,250,138 sheperdson July 22, 1941 2,280,943 FerrnY Apr. l28, 1'942 2,292,511 -Fei'm Y Y Aug. 1l, l1942 2,309,748 Nachtmah Feb. 32'0, 1945 2,395,437 Venable Feb. 26, 1946 2,418,088 Nach-tman Mar. 25, 1947 2,420,377 Jones May 113, 1947 2,428,362 Egge l(Det. A7, 1947 2,434,599 Stoitz Jan. 13, 1948 FOREIkG- PATENTS Number Country Date 258,633 Great Britain Sept. 21, 1926 357,575 Great Britain Feb. 23, l1931 492,066 Great Britain Y 1May -14, 1938