US1034858A - Pair-heating-furnace hearth. - Google Patents

Description

"1,034,858. Patented Aug. 6, 1912.

3 SHEBTRBHEET 2.'

Fig.6

INVENTOR T/Iomas V. A I i5 WITNESSES TUV. ALLIS. v PAIR HEATING FURNACE HEARTH. APPLICATION FILED SEPT.21,'1908. RENEWED NOV. 21. 1910.

3 SHEETS-SHEET 3.

WI TNESSES //VVEN7'0R TAO/has V 14/015 A TTOR/VEY Patented Aug. 6, 1912.

for the reason that cold bars may UNITED STATE PATENT OFFICE.

THOMAS V. ALLIS, OF BRIDGEPORT, CONNECTICUT.

PAIR-HEATING-FURNACE HEARTH.

To all whom it may concern' Be it known that I, THOMAS V. ALLIs, a

citizen. of the United States, residing at- Bridgeport, in ,the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Pair- Heating-Furnace Hearths; and. I do hereby declare the following to be a full, clear, a'nd'exact description of the invention,such as will enable others skilled in the art to which it appertainsto make and use the same.

' My invention relates to pair heating furnaces and it consists of an improved hearth designed to be .-used in the heating chamber of such furnaces to uphold sheet bars laced thereon. supporting them upon one oi their sides and'a lower longitudinal edge in a position inclined laterally to the perpendicular, thereby economizing space and increasing the heating capacity of such chamber, and when: employed in -continuously heating such bars, it enables them to be forced alon the hearth in parallel rows. The bene ts derived from the use of my improved hearthinthe ordinary pair heating chamber of the present sheet mill furnace consist: First-,*"m the ability to charge a greater number of said bars therein all more advantageously located than now possible, thereby giving them the necessary time to become mellowed by the mild soaking heat required for that purpose. Second, byheating the bars slowly they are brought to the proper rolling temperature without raising damaging scale upon their surface. Third, more continuous working is possible soon be charged after the hot bars are taken out, so that, by the time the hot bars have been progressively withdrawn along the hearth,

those at the opposite end from which the 'not bars were last drawn are in condition 1.0 roll, thus a system of rotative heating is established. Fourth, more bars are heated per unit of fuel consumed, from the fact that the hearth constantly receives and discharges the bars uniformly. Fifth, the work of the heater is less laborious as he -is not, under all conditions, obliged to ma nipulate and pile the bars Within the chamher. All of the above described benefits Specification of Letters Patent.

Patented Aug. 6, 1912.

:A ppliea'tion filed September 21,1908, Serial No. 453,977. ltenewed'November 21, 1910. Serial No. 593,545.

accrue alike in the use of my herein described improved .hearth in heating sheet bars in a continuous manner.

Figure 1 of the accompanying drawings s a. horizontal section of a gas fired continuous heating furnace taken on line a, a of Fig. 2 and shows in plan, collections of sheet bars cut to length with theirends crossed in reverse angular abutment and upheld upon my improved hearth within the heating chamber of said furnace. Fig. 2 is a transverse Vertical section on line b, b of Fig. 1. Fig. 3 is a section broken from said hearth through its base and the center of a portion of its vertical projections, with sheet bars standing in the grooves thereon formed by said projections and in reverse angular abutment; two of the collections of bars are shown in cross section, and portions of two in end elevation, all enlarged. Fig. 4 is an enlarged plan view of my improved cast steel hearth shown in Figs. 1 and 2: the base has integrally connected individual projections disposed over its top surface, which form a series of parallel grooves suitable to uphold therein sheet bars in angular position. Fig. 5 is a transverse vertical section on line 0, c of Fig. 4., Fig. 6 is a plan view in longitudinal section on line (1, (Z of Fig. 7 and shows the improved hearth constructed of burned fireclay or other refractory material and located'in the heating chamber of an ordinary pair heating furnace, the fire box and bridge wall common to such furnaces beingshown. Fig. 7 is a vertical longitudinal section on line 6, e of Fig. 6. Fig. 8 is a plan view in longitudinal section on .line f, f of Fig. 9 and shows collections of sheet bars all upheld at one inclination upon said hearth with their adjacent ends separated. Fig. 9 is a vertical longitudinal scctiomon line g, g of Fig. 8. Figs. 10, 1-1 and 12 are sections of varied forms of the hearth which may be constructed of metal or refractory material. Fig. 10, like Fig.,3,,.shows sheet bars upheld upon the hearth in reverse angular position having their ends twice crossed but supported more obliquely. F 1g. 11', also like Fig. 3, shows sheet bars upheld upon t'he hearth in. reverse angular position. but unlike Fig. 3, their ends are but once crossed and the bars are supported at a more acute angle. Fig. 12, like Fig. 9, shows sheet bars upheld at one and the same inclination to the erpendicular, the bars of Fig. 12, however, eing supported at a more obhque angle by grooves and projections of saw tooth shape.

are sheet bars. 11 the improved .hearth of varied shapes. 12 one of a se 10 ries of parallel upholding grooves in said hearth formed by parallel vertical projections. 13 the parallel vertical .projections which form said grooves and constitute a part of the hearth. 14 the lateral angular 5 bar supporting base of said projections and 15 the upper bar supporting portion. 16 that portion of the projections of the hearth (see Figs. 3 and 11)'which is uncovered by sheet .bars while in heated. 17 of Fig. 1, a shelf at the charging end of the heating chamber. 18 of Figs. 6 and 8 the side of the heating chamber of an ordinarypair heating furnace in which the charging and discharging doors are located. They consist of a series of comparatively small doors that raise vertically and overlap each other at their sides,

so that, while the large opening will be en- 7 tirely closed when the doors are all down, all parts of the hearth are madeaccessible through said doors. Doors not shown in thedrawings. 19 the chargin end of the continuous heating chamber 0% Fig. 1 and 20 its discharging end.

The upholding hearth embodies two well known axioms, First, that a collection of rectangular shapes of given dimensions standing upright upon one of their longitudinal edges with their" sides in contact, 40 occupy less transverse space than the same number of such shapes lying fiat-wise with their longitudinal edges in contact, and while I do not place sheet bars upon my hearth in the first position'above described,

I do in a modified way, upholding them upon their lower longitudinal, edge and one of their sides at a greater or less inclination to the perpendicular.

The second axiom availed of is, that two rectangular pieces of solid material having their abutting-ends crossed, can not be forced past each other or one over the other and that the power applied to move one piece moves its contacting neighbor in the same sustained line and direction; 1 To utilize the above described axioms, I construct my improved hearth with a series of parallel grooves formed by a series of parallel projections, which together torm a hearth having suitable grooves to uphold sheet bars placed longitudinally therein in a position inclined laterally to the perpen- 'dicularand in conformity to the second "axiom, the groovesbear such transverse refifrlation to each other that when longitudithe process of being.

hearth nal rows of said bars are consecutively placed alternately, angle within the prgjections, they-will cross at their adjacent en s.

Fig. 3 shows bars in collections standing reversed. and atan angle of 45; however,

in sections, at a reverse grooves formed by said as the degrees of lateral inclination to the.

perpendicular are immaterial to my inventhe side of an angle extending from said lateral base 14 to said outer portion 15 as great as the entire width of the bars, if

desired, when the bars are not to cross at their ends-above the projections.

One of the important benefits inherent-to the use of my improved hearth is the following: Although the hearth of a heating chamber contains more bars per square foot when supported thereon at an angle of 45 or thereabouts, than can be placedin the same space when laid flatwise with edges and ends in contact, I still secure upon the a large area of uncovered space 16, Fig. 3. This uncovered space is exposed to the normal. heat of the furnace which it absorbs, so that, when sheet bars are being heated in a continuous manner with their ends crossed in reverse angular abutment, each collection of bars is brought over the freshly heated supports which have been exposed to thesame heat and for the same length of time as the bars. Hence, all of the. collections of bars at each of their advanced steps-are brought. over the uncovered heated spaces which are of the same general caloric condition as the furnace, which not only prevents the under side of the bars tron. becoming chilled, but is a means of augmenting their temperature. The same advantages accrue to the use of my hearth when placed in any ordinary pair heating furnace, where, instead of arranging the rows of bars singlycr in collection alternately at a reverse angle, the rows, may, if preferred, all be placed at the same angle and in one direction, as shown at Figs. 8 and 9, there being no danger of the bars overriding each other as there is no impelling force brought against their ends, each collection being ma nipulated separately. In event of the bars all standing at the same angle and direction as shown in Figs. 8 and 9; it is obvious that the opposite surfaces of the supporting projections being largely uncovered by bars,

than one-half the against them and at a reverse angle to the preceding charge, the bars rest upon hot supports, so that, by alternating the position of each charge, the bars all have hot supports to rest against.

Vhile the hearth of Fig. 12 does not possess the foregoing described characteristics of the hearths of Figs. 3, 9 and 11 for recuperating heat in the portion 16 of the equiangular projections 13 of those figures; the grooves 12 ofFig. 12 are closer together than grooves 12 of Figs. 3, 9 and 10and 11, which gives the hearth of Fig. 12 greater bar upholding capacity per square foot than the hearths of said figures, the same' number of bars being placed in respective grooves.

In operating my improved hearth in the heating chambtu' of an ordinary pair heating furnace, (see Figs. 6, 7, S and 9) the bars are charged thereon through doors located in side 18 of the chamber, (doors not shown) singly or in collection. standing either at the same or reversed inclination.

Before the commencement of a week or working period, and in order to gain time,

the hearth is charged with its full comple-' ment of bars early enough to bring them all to rolling temperature by the time the turn comes on. Following the withdrawal of the hot bars, at one end of the hearth, to be rolled, others are charged to occupy reverse angular hot spaces in the same grooves.

have been withdrawn. at which time the metal at the opposite ends of the chamber from which heated bars were last drawn is hot enough to roll; thus a rotative system of heating is established which continues throughout the Working period.

To recover heat in the hearth of Fig. 12, the bars are manipulated somewhatdiffer ently from those of Figs. 8 and 9', and the act is accomplished by leaving the first groove 12, at the left of the figure vacant at the time the hearth is first charged with bars, which is after the hearth and all parts of the furnace have become'thoroughly heated. \Vhen such bars are partially heated, those occupying the first groove at the right of the vacant groove 12 are turned over toward the left into said groove, this leaves the first previously occupied groove vacant and exposed to the normal temperature of the furnace which. it soon assimilates; the next row of bars at the right of this re-heated rooveis then turned toward the left into it, and as it is the hot top bar of the pair that comes in contact with the now re-heated'surface of the groove, such groove is robbed of but little heat. This operation is continued un-, til all of the barsv across'the hearth have been turned into temporarily vacated and This operation is continued until all of the bars extending over the hearthany. approved means.

re-heated grooves, at which, time, the first bars turned are sufiiciently hot to roll. After the hot bars occupying the first two grooves 12. at the left end of the hearth have been drawn, cold bars are charged into thesecond groove 12, which leaves the first groove again open and prepared for a duplication of the operation, whichis constantly repeated.

In operating hearth 12, or any hearth of my invention herein described where'the" bars are turned in process of heating, it ispreferableto heat and manipulate them' in pairs instead of greater collections.

The hearths shown in Figsfi, '7, 8, '9 and 12 are composed of burned fire clay or any suitable refractory material and may be employed with economical results in the pair heating furnace of generaluse-where there is but little sliding movement of bars'over the hearths surface, although the cast steel hearth nextbelow referred to is'preferred.

The hearth of Figs. 1, 2*, 3, 4, and 5 is the type preferably adopted in the heating chamber of my' continuous heating furnace.

' It is by choice cast steel which is sufiiciently refractory to withstand the mild soaking heat required to mellow sheetbars and kindred metal. The hearth extends out in the form of a shelf 17 (Fig. 1) beyond the charging end 19 of said chamber a sufficient distance to uphold thereon sheet bars of the greatest length. Upon this shelf transverse rows of the bars are placed singly or in collection, and in the laterally inclined and lineal position they are to retain while passing along the hearth which is in the longitudinal direction of thelrl'ength as indicated by 'the arrow, and preferably with their ends twice crossed in reverse angular abutment as shown in Figs. 2, 3, and 10, although, if the chamber be short, the rows of bars may be forced over the hearth, all

standing at the same angle and direction as shown in Figs. 8, 9 and 12. The shelf 17 being filled, the bars thereon are next forced within the chamber by an. hydraulic am or shelf is again refilled with similar rows of bars which are also forced within the chamber. This operation is continued until the hearth is filled with bars its entire length. This completed, the bars are allowed to remain within the chamber until the trans verse row at its discharge end 20 has reached the proper-rolling temperature. The bars'of this row are then withdrawn and rolled. After said transverse row of bars has been exhausted and the shelf 17 reloaded, the propelling mechanism is again applied to The thus emptied the exterior ends of the transverse rows of bars standing upon the shelf 17, which forces them into .the chamber and-at the same time advances ,the entire charge a dis-, v tance equal to the length of said row of bars which occupied the shelf. This action brings a transverse row of bars to the discharge end of the chamber properly heated and. in position to be withdrawn the same as; said first row. 'This operation is congatan'tly but intermittently repeated throughout'the week or working period, The plan nace in advance of the first of heating bars in a continuous heating furturn at the commencement of a working period is to be barso'r other ,metal of-rectangular form in heating furnace,

: "various lengths of. any suitable within the heating chamber type of heating furnace. Having described my invention, What I claim as new and for which I desire to se-' cure Letters Patent, is

1. The herein described hearth ofa pair having its upper side composed of a series of parallel grooves suitable in form to uphold in angular position, sheet bars placed longitudinally therein.

2. The herein described hearth of a pair heating furnace, having its upperside composed of a series of parallel grooves suitable in form to uphold in angular position, sheet bars placed longitudinally therein; the distance from the bottom of the grooves to their extreme outer bar supportingportions being greater than one-half the width of said bars. 3. The herein described hearth of a pair heating furnace, having its upper sidecolnposed of a series of parallel grooves which bear such transverse relation to each other that longitudinal rows of sheet bars, in sections, supported alternately at a reverse angle within the-grooves and against the sides thereof, will cross at their adjacent ends.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

THOMAS V. ALLIS.

Witnesses:

Enxsr FRANCKE, D. F. NISBET.

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