US2348528A - Cooling means for rolls handling hot-rolled metal strip - Google Patents

Description

y 1944- A. E. E. DE wlTz 2,348,528

COOLING MEANS FOR iROLLS HANDLING HOT ROLLED METAL STRIP Filed March 12, 1942 4 Sheets-Shegtl INVENTOR May 9, 1944. A. E. DE WlTZ 48,

' COOLING MEANS FOR ROLLS HANDLING HOT ROLLED METAL STRIP Filed March 12, 1942 4 Sheets-Sheet 2 INVENTOR bis-4299mm;

May 9, 1944. A. E. E. DE wrrz I COOLING MEANS FOR ROLLS HANDLING HOT ROLLED METAL STRIP Filed March 12, 1942 4 Sheets-Sheet 3,

m 0 f M 5 m A i 1944- A. 'E. E. DE WITZ 2,348,528

COOLING MEANS FOR ROLLS HANDLING HOT ROLLED METAL STRIP Filed March 12, 1942 4 Sheets-Sheet 4 Patented May- 9,

, COOLINGM'EANS FOR ROLLS HANDLING HOT-ROLLED METAL STRIP Alfred E. E. De Wits, Bedford, Ohio, assignor to The American Steel and'Wire Company of New Jersey, a corporation of New Jersey Application March 12 1942, Serial No. 434,402

9 Claims.

In the hot rolling of steel strip there is frequently employed a unit referred to as a vibrator unit, which is positioned in alignment with the last finishing roll, for receiving the stripfrom the last finishing roll and retarding the speed of travel of the strip so as to render possible the inspection and gaging of the strip and 1 also to makepossible the manual insertion of the first end of the strip for the reeling,

or coilins, operation.

Such vibrator unit includes, essentially, two vertically mounted feed rolls, both of which are driven, the axis of one of the rolls being flxed,

while the other, is adjustable in order to enable crank mechanism operated from a motor and speed reducer separate from v drives the vibrator rolls.

the motor which The flipper unit is given a' back and forth motion which gives the hot strip a waving mo 'tion as it leaves the vibrator and distributes the strip on the run-out table in an edgeways wavy ribbon fashion, such distribution of thestrip from side to side on the table making'suflicient only a comparatively short run-out table, thus conserving on equipment and mill space.

As the strip at the vibrator unit is at rather high temperatures, say, for example, 1450- F., to 1650 F., and with ,a lineal speed of the strip at the vibrator unit anywhere from about 583 feet per minute to about 2633 feet per minute,

the vibrator rolls become hot, and serious difliculties have been experienced on account of overthe rolls, bearings, shafts; and

. "obviating/these difliculties, and many attempts have been made,'but unsuccessfully, to cool the parts afiected by the heat. The cooling problemv is complicated by the fact that, where high carboncontent strip is being produced, any cooling fluid employed for cooling the rolls and associated parts must'not'tome in contact with the hot strip because 'of the likelihood of .the

strip being quenched bysuch contact, and its structure changed thereby with attendant-dimculties in the reeling.

Among the attempts that have been made to eifect the requisite cooling, there may be mentioned the attempted use of cooling fans, of compressed air, and' water applied directly to the 5 rolls. The former attempts succeeded poorly, and the latter attempts were inoperative on account of the above-mentioned quenching ,,efl?ects on'the strip. Operating dimculties and the loss of bearings and gears through such over-heating showed that the problem involved in the successful operation of vibrator units in the production of hot rolled strip is to cool the vibrator at as near the source of heat as possible without interfering 16 with, or changing, the structure of hot rolled strip.

The source of heat referred to above is the hot strip itself, the vibrator rolls contacting therewith, and serving to feed the strip onto the mm- 20 out table without, however, reducing, deforming, or otherwise altering the strip.

In view of the failure of the attempts abovementioned to provide effective cooling, various changes were made in the lubrication system, all

.26 of which were ineflectual.

The problem of cooling the vibrator at as near to the source of heat as possible, without interfering with, or changing, the structure of high carbon hot rolled strip, flnally was solved through 80 the use of caps on the top of the vertically disposed :vibrator rolls into which caps water is allowed to flow at a rate slightly in excess of the rate of evaporation, the flow of water being under close control so as to avoid contact thereof with the strip being rolled.

The invention will be understood more clearly from the accompanying drawings, which show several forms of the invention.

In the drawings: 40 Fig. 1 is a plan view of a vibrator unit embracing the improvements of the present invention, the view including the flipper unit and run-out table, the direction of travel of the hot rolled strip being indicated by the arrow adjacent to the strip; V

' Fig. 2 is a fragmentary sectional elevation taken on the line II-II of Fig. 1, looking in the direction of the arrows:

Fig.- 3 is an enlarged plan view of the improved to vibrator unit of the present invention, heavy arrows showing fluid flow:

Fig. 4 is a fragmentary sectional elevation taken on the line IVIV of Fig. 3, looking in the direction of the arrows;

f Fig. 5' is a sectional elevation through the such accommodation.

entire vibrator unit, showing the drive mechanism for the vibrator rolls, as well as further details of the cooling means of the present invention;

Fig.6 is a sectional plan view on the line VI- VI of Fig. 5, looking in the direction of the arrows;

. to the housing 50..

Fig. 7 is a sectional elevation of a modified Q form of the invention, the view showing a fragment of a vertically disposed roll with the illustrated form of the invention applied thereto;

Fig. 8 is a plan view of the modification of I Fig. 7;

Figs. 9, 10 and 11 are fragmentary sectional elevations of further modified forms of the invention as applied to vertically disposed rolls, and,

Fig. 12 is asectional elevation of a modified form of the invention as applied to horizontal rolls.

Referring more particularly to the drawings,

' the vibrator unit is indicated generally at A, it

having a roll assembly generally indicated at .8, either vertlcalor horizontal, which is adapted to engage a hot rolled steel'strip C, and which is driven by a motor E. A flipper arm F is illustrated generally for pushing the strip C back and forth on a run-out table (3.

The vibrator unit A-comprises the roll assembly B, which includes two rolls l4, US which are generally similar, and which engage the hot strip C sufliciently to feed the strip onto the run-out table G. Both of the rolls are enclosed in a guard I8, which will be referred to further hereinafter, and both rolls are driven positively from a suitable source of power, such as motor E.

Roll I4 is shown as being mounted on a shaft 22, and roll I6 is mounted on a shaft 24. Shaft 22 has a bevel gear 26 keyed thereto, the said gear meshing with a bevel pinion 28 carried on the drive shaft 30, power from the motor thus being transmitted to shaft 22 for causing such shaft to revolve. Shaft 22 carries a gear 32 and shaft 24 carries a gear 34, suitable intermediate driving gears completing the gear train for driving the shaft 24 from the shaft 22 and motor E.

The shafts and power-transmitting means, therefore, are enclosed in a'housing 36 having a removable top portion 31 "arranged to be dismantled readily by removal-of bolts 39 for access into the interior of the housing for servicing the mechanism contained therein. Also, the bottom of the housing is provided with an opening, which is closed normally by a closure 38, .for providing access to bearing 40. Also housing 42 for driving shaft bearings 44, 46, may be dismantled'readily for permitting access to the bearings. Lubricating means for lubricating the lower portion of shaft 22 and its associated parts may be of any suitable type, such lubricating means being illustrated generally at'48.

As the mechanism is called Lpon to handle strips of different gages, adjustment of the spacing between rolls l4 and It must be provided for For this purpose, it is required that only one of the rolls be adjusted which, in the drawing. is shown to be theroll 18.

For adjustment of this roll, the shaft 24 and roll are arranged to be displacable laterally sufficiently to allow strips of different gages to pass between the rolls, as well as varying gages in one strip. The shaft 24, therefore, is enclosed in a housing 50 which contains the bearings 52 and 54 for the shaft, and adjustment of the shaft is effected by adjustment of springs 56, 50, actin on the housing 50 through a yoke 60 connected Vibratory movement of the unit A is efiected through a lever mechanism 62 operated by motor 63.

From the foregoing, it will be seen that the rolls l4 and i6 will become hot through contact with the strip C, heat also being conducted from the rolls through the driving shaft and driving mechanism, with destructive effect, were it not for the interposition of the means of the present invention which are designed to cool the rolls and associated parts of the mechanism.

The cooling means comprise, essentially, cuplike retaining devices positioned on the outer end of each roll, which devices are adapted to hold water which is supplied thereto at a rate slightly in excess of the evaporation rate, so that the outer end of the rolls will be enclosed in a continuously supplied body of water. Since means are provided for withdrawing excess of water, it will be apparent that the outer end'of each of the rolls is enclosed in a water'jacket through which water is maintained in continuous and vigorous circulation, whereby heat is withdrawn continuously from therolls, which are kept at temperatures below the boiling temperature of circulating water.

In addition to the mere cooling of the rolls, provision must be made to prevent access of the cooling water to the strip, on account of the fact that any contact of the water with the hot strip causes the strip to be modified unwantedly in its properties.

Various specific means embracing the same inventive thought are illustrated in the drawings.

In this connection, reference is made to Fig. 5,

the walls of which are the hubs 69, ll of the rolls and an annular flange 68, I0, the cap members 64 and 66 being secured to the flanges 68, 10 by means of bolts Ill. The resulting joints between the cap members and the rolls are made watertight by the provision of seals 12 and 14, the caps 64 and 66 thus defining with the ends of the rolls, a cooling jacket for each roll through which water is kept in continuous circulation, as will be described hereinafter.

1 Various means for circulating the cooling water are shown in the drawings. In Figs. 3, 4, and 5,'water enters through pipes 14, I6 and is withdrawn through pipes 18, 80, these latter being under suction through pumps 15 and 11, which outer pipes are included desirably, although optionally. Each of the pipes I4, 16.1s provided with a control valve 32, 84, for controlling the inflow of the water.

As has been pointed out above herein, it is important that contact be avoided between the water and the sheet or strip C. The intake and outlet pipes are positioned in tubular projections 88, of the cap members 64, 66, which projections communicate with the interior of the water jacket. for providing means of escape forv the steam produced from the water, which wateris introduced, as has been pointed out above hereinafter, at a rate slightly in excess of. the rate of evaporation. .The exhaust pipe in the cooling C, which space is .covered by a drain 06, the -retion 31 of the housing 36. The juncture between the housing 36 and its top portion 31 is made tight by a suitable sealing ring I06.

As will be seen from Fig. 5, the flow of water I is regulated bylthe valves 82, 84, so that the quantity of water admitted to the cooling jackets is under continuou control so as to be maintained in proper excess of I the rate of evaporation.

Naturally, a certain amount of the water retained in the jackets is thrown off tangentially from the top edge'of the cap projections 00. 90. The design ofeach roll guard housing 02, 04 is such that it almost completely encircles its roll;

All of this sprayed water, with the exception of that thrown on in the small angle above the drain 96, lies inside of the roll guards02, 94 runs down inside the guards, drops on the housing top 31 and drains off without interference with the strip C. The slight amount thrown ofl'above the spray-catcher 96 is caught thereby, and is drained away through the pipes I02, I04.

While from the foregoing, it will be seen that the outlet pipes and 80 and the pumps 16 and 11 may be eliminated, and the entire excess water allowedto spray out as described above, in practice it is found tobe desirable to provide such pipes for effecting closer control or balance of the water supply in the cooling jacket, particularly at roll speeds that are insutflcient to spray out the water as described above.

With the employment of the outlet pipes 10 and 00. it may be unnecessary to provide a spraycatcher. as it is possible to control water intake and outflow so that no water at all is sprayed cut of the jacket. But in practice, as a complete safeguard. it is desirable to utilize the spray- 'catcher 06.

When the spray-catcher is used, it is desirable to make it a component part of the roll guards 92, 94, the resulting assembly becoming thereby a unitary structure.

Fig. 7 shows a construction similar to that of Figs. 1 to 6,'inclusive; except that the straight- 9 shows a modiflcatiomwherein drainaie is effected through hole in the end web of the roll. In this view, the roll I is mounted on shaft I22 In housing I24 and is provided with a water cap I26, similarly as described above. Intake-pi e I20, provided with control valve .130, supplies water to the interior of the cooling jacket.

The end web I32 of the roll I20 is provided with holes I04. The water flows in from pipe I20 in controlled flow, and fills the jacket, draining out through holes I34 in the web I32, to the top of the vibrator housing, represented at I36 in Fig. '1. flowing from there to a drain not shown, contact between the water and strip thereby being avoided.

In Fig. 10 the roll itself is modified for internal cooling. The roll is indicated at I00, which is" mounted on shaft I40 in housing I42, this construction being the same a in preceding views. Water is supplied to the jacket I44 from a pipe I46 provided with a valve I40. The interior of the roll, which is hollow, is divided by a top web I50 and a bottom web I52, which define between them a coolirfg chamber I54. Holes I56 pass through the top web and holes I68 pass through the bottom web, through which holes water passes, the flow being controlled so that the chamber I64 15 filled. The water flows out from the roll through bottom holes I50, and over the top I60 of the vibrator housing, as-has been described above, without contacting with the strip.

Fig. 11 shows a further modification wherein ".e roll. I62 has an open end and a water spray I64 'is insertedwithin the roll to cool it through the cooling eil'ects of jet of water sprayed into the roll. The excess water drains over the vihratc-r housing, as has been described above, and it does not contact with the rolled strip.

Fig. 12 shows a modification as applied to horizontal rolls. The rolls are indicated at I66, I66; water caps I10. I12 are applied thereto through which enter the water supply pipe I14 and drain pfpe I16. The supply pipe I14 ha a curved end I-18 for supplying water to the outer wall of the water jacket and pipe I16 is curved as indicated at I00 to withdraw water from thecylindrical layer I82 thereof, which is formed by centriiug'al force incident to omrative rotation of the rolls. Pipe I16 acts as a syphon to remove excess water from the cooling jacket. a suction pump I 04 being inserted in the pipe I16 if desired.

ended outlet pipe of Fig. 5 is replaced by an out-"1 let pipe having a curved end-which is designed to reduce further any amount of water sprayed from the cooling jacket. In Fig. 7, the roll Hi6,

which is entirely similar to the rolls I4,-.I6 is mountedon a shaft I01 enclosed. in a housing I00, and i provided with a water cap I08, similar to the caps 64, 66. The water intake pipe is indicated at 0, and is controlled by a valve H2. The drain pipe is indicated at H4, which. in the present modification, hasa curved end II6 ,which is placed so that its opening I I0 is-disposed ol Positely to the direction of rotation of the roll. The motion of rotation of the roll produces a pumping action which forces the water from the jacket. although, of course, the action may be augmented by the useof 'a suction pump, if such is found to be desirable. S nce the end IIB of pick up. water thrown to the periphery by centrifugal force of rotation.

In all of the illustrated forms, it will. be seen.

that as the rolls turn, the speed of rotation forces the water into the shape of a cylinder which is held by the outer wall of the cooling, chamber and adjacent to the zones of max mum heating of the roll. Also, the outlets are positioned so that the heated water is withdrawn continuously as it becomes hot. and immediately and continuously becomes replaced by fresh cold water. Therefore,

- there is maintained the maximum coolingetfects the patbs'of heat flow are mainly. through these outer portions of the roll, so that destructive heat is prevented fr m passing into the body ofthe rolls to the drivingishaft upon which the roll is mounted, thereby giving the max mum cooling eifects.

I claim:

1. Apparatus for feeding hot rolled steel strip onto a run-out table, which comprises the com-' bination with a pair of feed rolls adapted to engage a hot strip and to become heated thereby,

rate somewhat in excess of the rate of evapora-' tion, outlet means for the water, causing the said water to be constantly withdrawn, whereby a substantially constant amount of water is retained in thecooling chamber, the said chamber having an outer wall adapted to retain a cooling cylinder of the water produced by centrifugal force of rotation of the roll,the said cylinder being located adjacent to the areas of maximum.

heating of the roll, and in heat exchanging relation thereto, whereby excessive heat is prevented from passing into the body of the roll, and means for preventing heated water being withdrawn from contacting with the hot strip being handied-by the rolls, the said outlet means being positioned to continuously withdraw water from zones of maximum heat, thereby enabling continuous replenishment thereof with fresh cold water.

2. Apparatus for feeding hot rolled steel strip onto a run-out table, which comprises the combination with verticall disposed feed rolls adapted to engage both sides of a hot strip and to become heated thereby, each of the said rolls presenting a top end, cooling means on the top ends of the rolls coextensive therewith, the cooling means including a cap mounted on each of the rolls, each cap defining with its roll a chamber adapted to contain water in heat exchange relation with the roll, means for continuously introducing water into the chamber, means for controlling admission of water to the chamber at a rate somewhat in excess of the rate of evaporation of the water, outlet means for the water causing the said water to be constantly withdrawn, thereby preventing overflowing of the chamber and assuring continuous circulation of fresh cold water in the chamber, the said chamber including an outer wall adapted to retain a continuously renewed cylinder of cooling water produced and maintained by centrifugal force of continuously renewed cylinder of cooling water produced and maintained by centrifugal force of rotation of the roll, the said cylinder being located adjacent to the areas of maximum heating of the rolls and in heat exchanging relation thereto, whereby excessive heat is prevented from entering substantially into the body of the roll.

4. Apparatus for feeding hot rolled steel strip onto a'rnn-out table, which comprises the combination with vertically disposed feed rolls adapted to engage both sides of a hot strip and to become heated thereby, each of the said rolls presenting a top end including a web, of cooling by preventing overflowing of the chamber and assuring continuous circulation of fresh cold water in the chamber, the said chamber-including an outer wall adapted to retain a continuously renewed cylinder of cooling water produced and maintained by centrifugal force of rotation of the roll, the said cylinder being located adjacent to the areas of maximum heating of the roll and in heat exchanging relation thereto, whereby excessive heat is prevented from entering substantially into the body of the roll.

5. Apparatus for feeding hot rolled steel strip onto a run-out table, which comprises the combination with vertically disposed feed rolls adapted to engage both sides of a hot strip and to become heated thereby, each'of the said rolls presenting a top end, cooling means on the top ends of the rolls coextensive therewith, the coolrotation of the roll, the said cylinder being 10- cated adiacent to the areas of maximum heating of the rolls and in heat exchanging relation thereto, whereby excessive heat is prevented from entering substantially into the body of the roll, and means for preventing heated water being withdrawn from contacting with the hot strip being handled by the rolls.- 1

3. Apparatus for feeding hot rolled steel strip onto a run-out table, which comprises the combination with vertically disposed feed -ro1ls adapted to ,'engage both sides of a hot strip and to become heated thereby, each of the said rolls presenting a top end, cooling means on the top ends of the rolls coextensive therewith, the cooling means including a cap mounted on eachof the mils, each cap defining with its roll a chamber adapted to contain water in heat exchange relation with the'roll, means for continuously introducing water-into the chamber, means for controlling admission of water to the chamber at a, rate somewhat in excess of the rate of evaporation of the water, and outlet means for the water causing the said water -to be constantly withdrawn, thereby preventing overflowing or the chamber and assuring continuous circulation of fresh cold water in the chamber, the said chamber including an outer wall adapted to retain a ing means including'a cap mounted on each of the rolls, each cap defining with its roll a chamber-adapted to contain water in heat exchanging relation with the roll, means for continuously introducing water into the chamber, means for controlling admission of water to the chamber at a rate somewhat in excess of the rate of evaporation of the water, and an outlet pipe extending into the chamber and having-its open end disposed in opposition to the direction of rotation of the rolls, thereby -causing water from the chamber to be withdrawn constantly from the chamber, thereby preventing overflowing of the chamber, and assuring continuous circulation of fresh cold water in the chamber, the chamber including an outer wall adapted to retain a continuously renewed cylinder of .cooling water produced and maintained bycentrifugal force of rotation of the roll, the said cylinder being lo? cated adjacent to the areas of maximum heating onto a run-out table, which comprisesthe combination with feed rolls adapted to engage both sides of a hot strip and to become heated thereby, cooling means for the rolls comprising a cap mounted on an end of each roll defining with theroll a chamber adaptedto contain water in heatexchanging relation with the roll, means for introducing water into the chamber, means for con- .ing chamber while avoiding overflowing of the, chamber, the said chamber having an outer wall adapted to retain a cooling cylinder of the water produced by centrifugal force of rotation of the roll, the said cylinder being located adjacent to the'areas of maximum heating of the rolls and in heat exchanging relation thereto, whereby excessive heat is. prevented from passing into the body 7 oi!v the roll, guard means for the rolls substantially enclosing the rolls, and meansmounted on,the

guards for receiving and retaining spray ejected from the said chambers during rotation of the rolls and projected beyond the limits oi the, roll guards, thereby preventing contact of water with the hot strip being handled by the rolls.

7. Apparatus for feeding hot rolled steel strip onto a run-out table, which comprises the combination with vertically disposed reed rolls adapted to engage both sides 01 a hot strip and to become heated. thereby, each of the said rolls presentlng a top end, of cooling meanson the top ends of the rolls coextensive therewith, the cooling means including a cap mounted on each or the rolls, each cap defining with its roll a chamber adapted to contain water in heat exchanging relation with its roll, means for continuously introducing water into the chamber, means for controlling admission of water to the chamber at'a rate somewhat in excess of the rate oi evaporation or the water, and outlet means in the roll for the water causing the said water to drain through the interior of the. roll, thereby preventing contact of water with the hot strip being handled by the rolls and preventing overflowing oi the chamber while assuring continuous circulation of fresh cold water in the chamber, the said chamber including an outer wall adapted to retain,a continuously renewed cylinder of the water produced and maintained by centrifugal force of rotation of the roll, the said cylinder being located ad- Jacent to the areas of maximum heating of the roll and in heat exchanging relation thereto,-

whereby excessive heat is prevented from entering substantialhr into the body of the roll. 8. Apparatus for feeding hot rolled steel strip onto a run-out table, which comprises the combination with horizontally disposed feed rolls adapted to both sides of a hot strip and to become heated thereby, each of the said rolls presenting and outer end, cooling means on the outer ends of the rolls coextensive therewith, the cooling means including a cap mounted on each oi the rolls, each cap defining with its roll a chamber adapted to contain water in heat exchange relation with the roll, means for continuously introducing water into the chamber, means for controlling admission of water to the chamber at a rate somewhat in excess or the rate of evaporation or the water, and syphonic outletv means for the water causing water to be withdrawn continueously from the .chamber, thereby preventing overflowing of the chamber and assuring continuous circulation of fresh cold water in the chamber;

the said chamber including an outer wall adapted to retain a continuously renewed cylinder of cooling water produced and maintained by centriiugal force of rotation of the roll, the said cylinder being located adjacent to the areas or maximum heating of the rolls and in heat exchanging relation thereto, whereby excessive heat is prevented irom entering substantially into the body of the roll.

9. Apparatus for feeding hot rolled steel strip onto arun-out table, which comprises the combinationewith ieed rolls adapted to engage both sides of a hot strip and to become heated thereby, each of the said rolls being hollow, and cooling spray means positioned interiorly of the rolls adapted to spray cooling fluid against the rolls,

the said rolls having an open end and having a portion defining a protective apron enclosing the spray means and preventing engagement of the spray fluid with the hot strip being handled by the rolls,

' ALFREDEEDEWITZ.

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