US1878971A - Roll heater - Google Patents

Description

Sept. 20, 1932- ,1. MILNES ET AL ROLL HEATER Filed May 2, 1931 3 Sheets-Sheet N VE/V TO R5 Jzufles ill/2e35,

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.HTTORNEYJ' WITNESS Sept. 20, 1932. J. MILNES ET AL ROLL HEAT ER Filed May 2; 1931 5 Sheets-Sheet 2 WITNESS Sept. 20, 1932. 'J. NHLNES ET AL ROLL HEATER Filed May 2, 1931 5 Shee'ts-Sheet &

I)!!! Il'illl lll' Ill I Pil -kid 7 3 m B m m m 5 4 m 0 55m WW5 V g 7 dam VV/T/VESS may Patented Sept. 20, 1932 UNITED STATES J'AMES MILNES, OF STRUTHERS, AND RAY'Ei HOWELL, OF POLAND, OHIO ROLL HEATER Application fiied'Ma 2, 1931'. ,Serial No. 534,505.

The present invention relates to means for heating the rolls of a rolling mill preparatory to their being utilized for hot rollingsheets,

7 plates, and the '-like.

For satisfactory rolling of certain classes of these articles it is, requisite that the rolls J V, practiceis, however, unsatisfactory and un- 29 economical for, as the temperature of the rolls increases, their dimensions vary somewhat as the result of their expansion with consequent variation in the thickness of the'rolled sheets,

i while until the rolls attain the proper rolling temperature the finish on the material passa ing therethrough is more or less imperfect. As a result, many of the sheets rolled during the heating operation do not meet the re-' 'quired commercial standard and-must be 30 classed as'seconds, while as the" rolls are usuallygof relatively large mass the time requiredfor heating them in this way to the desired temperature is excessive with the re- .i sultthat the entire mill and associated mech anlsms are necessarlly engaged for several hours in relatively unproductive or at least inefficient operation before a proper rolling condition isobtained. i i

With, a view to obviatingthe disadvanges of the heating-up method to which reference hasjust been made, various forms of mechanical means have been suggested for heating the rolls either in'the mill stand or in an apparatus separate therefrom but, so far as r we are aware, all of them are open to the objection'that the rollsmust be rotated for the several hours required to heat them evenly and uniformly and therebyavoid the setting up of internal strains,cracking,burningf and other inim'ical effects incident to uneven ortoo rapid heating or impingement of a heating flame for too long aperiod on the roll surfaces,- Consequently, a very large amount of poweris unproductively expended in driving the rolls while they are being heated up, particularly, and as usually the case, when the rolls are of largesize and weight,iwhile a further disadvantage of this class of apparatus when designed to operate on the rolls while the latter are disposed in the mill stand resides in the fact that the mill isnecess'arily.

idle insofar as itsprimary function is concerned while the rolls are being heated, withv resultant lowering of its possible productive H capacity. k

For the reason last mentioned, the use of apparatus adapted to heat the rolls prior to their being placed in the mill is generally preferred but since, as just explained, it has hitherto been necessary to rotate the rolls when disposed in the heater in order to heat them uniformly and evenly, the cost of bringing the rolls to the proper temperature because of the power required to drive them during the heating operation has been excessive. Consequently, as the power so used is totally unproductive, some operators prefer todispense with a separate heater and t0 employ the heating up method to which We have'initially referred, since in that way the power expended for driving the mill is at leasttoxsome extent usefully employed even though much of the rolled material produced'before the rolls have attained the most desirable rolling temperature is not of first quality. j

A principal object of the present invention, therefore, is to provide a roll heater of the type in which the rolls are heated apart from the mill stand, yet of such character that the heating may be satisfactorily ac..- complished with. the'expenditure of a mini mum amount'of power; which may be operated by unskilled labor and substantially that to which reference has just been made in which the rolls remain stationary throughout the heating period and the heating means are oscillated with respect to the rolls ,so as to properly distributethe heat thereover with resultant negation of localized heating and the inimical effects incident thereto. 7

A still further object of the invention is the provision of a roll heater adapted to heat the rolls when stationarily supported-therein through the medium of a plurality'of'gas or other suitable burners disposed adjacent theretoand arranged for relative oscillationwith respect to the rolls incombinationwith means for effecting such".osc'illation, whereby as the massof-the oscillatory burners and.

simple yet rugged construction; which is not liable to get out of'order or become damaged under the conditions'of use towhich it is necessarily subjected in the performance of its intended function, and in which the heat iseffectively'usedwith resultant economy in operation.

Other objects, advantages and novel f ea-f tures of construction and arrangement comprehended by the invention are hereinafter more specifically mentioned or will be apparent from the following description of a preferred embodiment thereof, reference being had to the-accompanying drawings.

. As will hereinafter more fullyappear, that embodiment of the invention herein shown and described is intendedfor heating one pair of rolls "at a time, the rolls during the heating operation being substantially enclosed within a suitable casing which forms: the heatingv unit. or chamber and in which suitable burners are arranged in proximity to each of the rolls for relative oscillation with respect thereto. 'Howeven'if desired, plurality of the heating units may be pro..

vided, each designed to contain a pair of rolls andtheseveral burners respect vely d1s-' posed therem oscllla-ted from a slngle-power source or, under certain conditions, each heating unit may be arranged to contain more than a pair of rolls and the burners there n similarly oscillated from a single power source, all as hereinaftermoreparticularly. V v v necks; The coveris preferably provided with pointed out. p it I In the accompanying drawings,fFig. 1 is a top plan view: of, the roll heater showing a pair of rolls disposed therein position to be heated preparatory to being-transferred to the mill stand, portions of the cover. of the; heating unit being broken away for clearness;

ofillustration; Fig. 2 is a longitudinal vertical staggered section substantially on the,

Figzflis a detail top plan viewof one of the burners and associated parts removed from the heater, and Figyii 'is a side 'ele'vation of the structure shown in Fig. 4:, portions of the-branches of the burner being broken away into vertical section. In the several figures like characters are used to designate the same-parts. V

Broadly considered, the 7 roll heater illus; trated comprises means for supporting a pair of rolls in horizontal parallel relation within a casing which is substantiallyclosed during the heating operation and portions of which may desirably be heat insulated in. order to eifectconservati'on' of fuel .by. reducti on of radiation; within this casing gasburnersor other heating means are disposed adj acent.

the rolls and arrangedfor oscillation: with re; spect thereto, while suitablemeans are-provided for effecting. such oscillation inorder surfaces.- j

to "properly distribute the heat over the roll l M ore particularly, the heating unit, ener ally. designated 1, in which the rolls R; are disposed 'comprisesahollow, generally rectangular base ,2, conveniently a single unitary casting, the sides of which are provided intheir upper surfaces with longitudinally spaced transversely aligned semicylindrical recesses '3, 3 adapted to receive andform seats for, the necks of the rolls when the latter are lowered intoplace therein by IQO acrane'or other'suitable means. These recesses arev so arranged that the rolls when disposed therein. will lie in longitudinally spaced relation as best shownv in Figs. 1 and '2 with the central portionsor barrels of the rolls which are to be heated between the sides of the base which latter is desirably provided with a transversely extendingweb which servesto tiethe sides of the basetogethermidwayof its'ends; The upper horizontal surface ofthebase is fiat to form a seat for a remov able'cover 5 which is desire ably formed of sheetmetal suitably braced and so shaped, as best shown in Fig. 2, as to lie'fairly; closely adj acenttherolls when the latter areidisposed-in the unit, the sides of the coverbeingprovided with semicircular cut-outs to receivethe upper halfjof the roll aheat insulating lining 6.and with lifting eyes 7 to enable it-to be conveniently removed from theibase, while at its center a flu-e- 8,-

shown or may be connected with a chimney or the like so as to remove the spent gases '5 is removed the rolls R, R" can readily be lowered into position in the base and that when the cover is thereafter replaced, the

upper halves of the rolls will lie in a substanv tially closed chamber formed by the cover and the lower halves in the chamber formed in the base. I

Within the base beneath each roll and'ex tending up on each side thereof considerably beyond its axis, is disposed a jacket 10 in which the burners are secured, and since the arrangement of the jacket, burnersand'other parts is the same for each roll, we shall refer moreiparticularly to those adjacent the roll R, the corresponding parts adjacent the other roll being designated by the same numbers with the addition of a prime (1) Each jacket, which may desirablyhbe a unitary and relatively light casting although under certain conditions it may be made of sheet metal suitably strengthened and reinforced, fol lowsin transverse section the contour of a circle of somewhat greater diameter than the barrel of the adjacent roll but is cutaway on its upper side sufficiently to permit the roll to be lowered into and removed from the roll seats in the base; is arranged coaxially with the roll, and is supported for oscillation thereabout on semi-circular oppositely, in-

wardly directed flanges 11 integral with the sides of the base, bearing shoes 12 of hardened steel,bronze or the like beingdesirably interposed between theifianges' and the'adjacent ends of the jacket so as to minimize wear;

The adjacent inner ends of the flanges desir ably merge into the transversely; extending web c'and their outer ends'into the adjacent upper marginal portion of ,the'base,

Within each jacket is arrangedaheating burner, the -construct1on of which is best shown in 'Figs; 4 and 5, from which it will be noted that each burner comprises a plu:

rality of parallel circumferentially spaced pipes M adapted to extend axially ofthe roll and which are perforated, on their inner faces for the passage of the heating gas. These pipes, four of which are usually provided, are connected bya transversely ex tending header 15 suitably curved to con nected to a flexib-letube" 17 of metal or-rubher in turn connected at its lower endto a horizontally disposed pipe 18 extend ng to a swivel joint 19 communicating with "the main supply pipe 20 as-best shown in 8. Thus, when the jacket oscillates as herein,-.

after described, the horizontal pipe 18 can swing about theswivel joint 9 while the flexible tube 17 can move upon itself'as required so that the flow'of gas to the burner pipes of the movements ofthejacket. For convenience of illustration, thepipe 18 and adjacent parts are omitted from Fig; 2. r y r 1 The burner pipes 14, header 15 and pipe 1lis at all times maintained irrespective "tov 16 may desirably be welded togetherso as to form .asingle unitary structure, which after disposition in the jacket is rigidly connected to the inner surface thereof by strap-s 22 extendingover theipipes 14 at'suitable intervals'or in any other convenient way;

It will thus'b-e apparent that eachjacket with its contained burner is capable .of axial oscillation with respect to the roll about which'it is disposed and suitable means are provided for effecting this oscillation of both jackets simultaneously during-the heating lower end of a rocker arm29 extending generally vertically and mounted on a'horizontally extending shaft '30 carried in, suitable pedestals 81, the rocker arm comprising either a pair of similar elements disposed on opposite sldes of the connecting rod. Thearm is extended above .theshaft 30 and there'pivsource of power adapted to rotate the shaft 34. It will, of course, be understood that the form and'construction of; the reduction gear is a matter of choice, so long as it is effective to bring about a suitable reduction in speed between the motor shaft" and the shaft 34 and, incidentally,corresponding increase in power. .As shown, the motor and reduction gear may conveniently be mounted on a suitablebase adjacent the pedestal 81, which,

a single element or preferably, and as shown,

iot-

iio

under ordinary conditions, will be located quite closely adjacent the base 2 so asto reduce the length of the connecting rod 26.

'As-the arms 25, 257arebothconnected to the rod 26, the generally reciprocating move-; ment of the latter communicated thereto by;

the rocker arm- 29 is effective to oscillate the jackets-10, 10' and burners carried thereby about the rolls R, Rsimultaneously, the va- 9 are desirably made as narrowas may he without interfering with the passage of the rolls;

rious parts through'whichthe oscillation of the jacketsi's'brought about being preferably so arranged that the amplitudeof movement is suflicienttomove each of the burner pipes 14 "through overlapping; or substantially overlapping arcs so as to'efi'ect aneven' dis tribution of the heat from the several burner,

pipes over the surface of the adjacent'rolL I In theparticular. embodiment of the inven tion shown, the partsare so arranged that narily immaterial since the temperature in the upper part of the'heating unit is usu- V ally considerably greater than at lower levels therein, but it will readily be apparent thatby giving the'jackets a slightly greater am; plltude of oscillation through a suitable arrangement ofthe driving means the paths of the burners '14 adjacent the top of'the' roll can be'cau'sedfto overlap and the entire surface of the'roll thereby exposed to the direct action of the. heating flames." q s It will be noted that the diameter of the ackets is suflicient to'afl'ord an ample clearance between the burner pipes and the sur- 7 face of the rolls and that the jackets are desirably provided withinwardly directed end flanges 40 whose inner edges lie more closely adjacent the roll surfaces to assist in prevent ing the escape of" heat endwise therefrom,"

while the openings in the jackets through which the rolls are introduced and removed- While the apparatus shown in thedrawdings comprises'but a single heating unit 7 adapted to receive a pair of rolls, a plurality of such units ifdesired may readily be'dis posed in longitudinal alignmentand therespective jackets and burners thereof oscillated from the'same'sourceof power by mere ly' continuing the connecting re d' 26 through the several units 'as 'indicated in broken lines in Figs. 1 and 2,or eachunit maybe arranged" to receive morethan a single pair of rolls,

thus in either caseenablinga plurality' of pairs of rolls to be heated'at the same time.

Since the combined mass of'the moving parts including the jackets and burners is relatively light iii comparison to the-mass of the rolls with which they are operatively associated, the power required-for 'o'scillating them is relatively small in comparison to that which would be required 'fordriving the rolls so that, through the medium of'ou-r' invention, theadvantages incident to heat-'- a ing the rolls apart from the mi'll stand can be secured without entailing thelarge 'exv appended claims; is

" 2. A roll pense?forunproductivespowei' incidentsto the use "of separate heaters in which the rolls must be rotated orderto: properly heat them. Moreov'er, since: the heating flames are constantly-being moved over thesurface of the rolls while the heatingis in progress, the chance of localizedheating is obviated, while :as vthe heat is-efliciently applied and retained in proximity to the rolls the heating of the. latter isuniformly, evenlyand rapidly eifected with a'minimum expenditure offuelfl 'While; we have. described oneembodiment of our invention with considerable partieu larity,-'we :dovnot thereby desire orintend to specifically confineor 'limitburselvesthere? to'or toia'ny precisedetails in the design and construction of the various parts, as numer 1 ous changes and modifications may be made bothinithe: general arrangement of-the principal elements and ,in constructional details thereof without departing" :from the spirit and scopeof the invention: as' defined in the Having thus described our invention, we

claim anddesire to protectbyLettersPatent of the United States: .1 1; A roll heater comprisingmeans adapted to support the roll/to beheated,heatingmeans,

meansfor'supporting saidheating means adjaoent the roll when disposed-in heatingposit-ion, and means for causing rotativ motion of said heating means relative to the roll surfaces 1* H I I h'eater comprisingmeans adapted to support a ro'll to be heated, heating means, means forsupporting said'heating means ad-f jacent the surface of'the roll-when disposed in heating position, and means operable to move the heating means relatively to-the roll in a'path substantially concentric therewith; 3. A rolllheatefcomprising meansadapted 'to stationarily support therolltobe heated, a heatingbu'rner adapted to partially surround and to'direct a' 'plurality of flames toward "the surface of the roll when disposed in'heating position,"means for supporting the burner for limited oscillation;circumferen said supportingmeansr- 1 .7 p V 4; A roll heater comprising abase arranged tosupport'the roll to -be heated, a removable cover for the base adapted tosubstantially enclose the roll when disposed in heating position, a burnerhavinga plurality of annutiallv of the roll, and means for oscillating larly spaced branches, means for "supporting.

the burner coaX-iallyvvith the roll, and means foroscillating said supporting mea'ns and the burner relatively tothe roll." a

5; Aroll heater comprising a base provided over the base and adapted to' substantially I withseats for supporting thenecks of the rolls to be heated, 'a' removable cover extending;

operative to partially surround the roll, a burner disposed in the interior of the'jacket operative to direct heating flames toward the roll, and means for oscillating the burner and the jacket as a unit relatively to the roll.

6. A roll heater comprising a hollow base provided'with seats for receiving the necks of the roll to be heated and inwardly directed, substantially semi-circular flanges arranged coaxially with said seats, a jacket sup-V portedon said flanges and adapted to partially surround the roll, a burner disposed in the interior of the jacket and having a plurality of branches extending parallel to the axis thereof, means for conducting a heating medium to the burner, and meansifor oscillating the jacketon said flanges.

7. A roll heater comprising a hollow base provided with seats for receiving the necks of the roll to be heated and inwardly directed, substantially semi-circular flanges arranged coaxially with said seats, a jacket supported on said flanges and adapted to partially surround the roll, said jacket having an opening in its upper portion through which the roll can be introduced, a burner disposed in the interior ofthe jacket and having a plurality of branches extending parallel to the axis thereof, means extending through the wall of the jacket for conducting a heating medium to the burner, and means for oscillating the jacket on said flanges. r

8. A roll heater comprising a hollow, substantially rectangular base provided with seats adapted to receive the necks of the roll to be heated and with inwardly oppositely directed, substantially semi-circular flanges respectively disposed adjacent and coaxially with said seats, a removable cover for the base, a jacket supported on said flanges and having an opening through which the roll to be heated may be disposed inside the jacket and on said seats, a burner having a plurality ofbranches extending parallel'with the axis of the jacket and secured in the interior thereof, means for supplying a heating medium to the burner, and means including a connecting rod extending to a po1ntremote from the base, a rock shaft, and means for actuating the rock shaft operable to oscillate the jacketabout its axis to thereby cause the'burner to reciprocate circumferentially about the roll through a limited are.

jacket about its axis with an amplitude sufficient to cause the paths traveled by adj acent branches of the burner to overlap.

10. A roll heater comprising a base having seats adapted to receive the necks of the roll which is to be heated, a jacket adapted to partially surround the roll when disposed on i the seats and extending within the base,

axes in parallel spaced relation, a jacket v adapted to partially surround each roll when so supported, means operative to support the jackets for oscillation about their respective I axes, a burner disposed in each jacket, means for supplying a heating medium to the burners, and means for oscillating both jackets simultaneously about theirrespective axes.

12. A roll heater comprising means for stationarily supporting a pair of rolls with their axes in parallel spaced relation, a jacket adapted to partially surround each roll when so supported, means operative to support'the jackets for oscillation about their respective axes, a'burner disposed in each jacket and comprising a plurality of circumferentially spaced branches extending parallel to the axis I of the jacket, means for supplying the heating medium to the burners, and means for oscillatlng both jackets simultaneously about their respective axes through anarcsufiicient to cause the paths traveled by adjacent branches of the burners to overlap.

13. A roll heater comprising means adapted to support a roll to be heated, heating means, means for supporting said .heating means adjacent the roll when disposed in heating position, and means operable to oscillate the heating means relatively to the roll.

14. A roll heater comprising means adapted to support a roll to be heated, heating means, means for supporting said heating means adjacent the roll when disposed in heating position, and means operable to oscillaiiti. the heating means about the axis of the ro In witness whereof, we have hereunto set our hands this 29th day of April, 1931.

JAMES MILNES.

E. HOWELL. f

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