US1738130A - Continuous-heat annealing furnace - Google Patents

Description

F, .11.. WINDER Wemm 3 1929},

CONTINUOUS HEAT ANNEALING FURNACE Filed March 50, 1928 2 Sheets-Sheet l INVENTOR.

ATTORNEYS.

IF 3, 192%, PL J. WINDER 1,733,130

CONTINUOUS HEAT ANNEALING FURNACE Filed March 50, 3.928 2 Sheets-Sheet 2 m j z .flv: 3 y 2 5 INVENTOR.

BY jjzgm 4L ATTORNEYS.

Iii

ously moving i atented Dec. 3, 1929 UNITED STATES PATENT OFFICE WK 3'. WINDEB, OF BBAGKENBIDGE, PENNSYLVANIA, ASSIGNOR '10' AIJIEGHENY STEEL COMPANY, A. CORPORATION OF PENNSYLVANIA GQNTINUOUS-HEAT ANNEALING FURNACE Application filed larch 30, 1928. Serial No. 265,924.

This invention relates to the annealing of steel, iron, or alloy metal. a In the manufacture of all types of sheets, i it is advisable, as far as possible, to secure flatness and it is therefore advisable to have the sheets fiat during annealing thereof. It is also advisable to prevent scratching or otherwise marring the sheets during annealing. y

In the manufacture of certain types of sheets, such as full finished sheets, it is advisable to carry on the annealing in a nonoxidizing or in a reducing atmosphere, while with other types of sheets, such as silicon steel sheets, it is advisable to carry onthe annealing in such a manner that the gases given off from the material during annealing are carried away in order to prevent re-absorption thereof.

With sheets such as full finishedsheets, it is advisable to hold the same in the nonoxidizing or reducing atmosphere until they are cooled to a point rapid oxidization or free scaling occurs and it is advisable from many angles with all types of sheets to carry on the annealing as a continuous process.

An object of this invention is to provide a method of and apparatus for carrying on the continuous annealing of steel iron or alloy sheets in suspended and flat or substantially flat condition and out of contact with any supporting means except along the upper edge thereof.

Another object is to provide a method of and apparatus for carrying on the continuous annealing. of sheets in such a manner or by sucha means that the sheets are suspended and depend from a support capable of continthe sheets during the annealing operation and until the same have cooled to the desired temperature.

Another object is to provide a method of and apparatus for carrying out the continuous annealing of sheets, wherein the aparatus is provided with an improved means or supporting the sheets durmg the annealing operation, such means being capable of supporting two rows of sheets and continuthe sheets during the annealbelow that at which ing operation and thereby increasing the production of such sheets and rendering this production less expensiye;

Astill'further object is to produce an anhealing furnace which, by but slight changes. is adapted for carrying on the annealing of sheets in either a reducing or non-oxidizing atmosphere or in such a manner that free circulation is provided, whereby gas given off from the sheets during annealing may be rapidly carried away in order to prevent reabsorption thereof. 1

In a general way, the method consists in suspending the sheets along one edge thereof to a support adapted to carry them edgewise and in succession through a relatively long annealing chamber. In the case of full finished sheets, the chamber is more or less tightly sealed against the ingress of air and is preferably heated in such a manner that either a non-oxidiaing or reducing atmosphere is obtained within the chamber.

In the case of other types of sheets in which it is not necessary to maintain any particular kind of atmosphere, the ends of the annealing chamber are left open in order to provide more or less circulation through the same.

These as well as other objects which will be I apparent to those skilled in this particular art are attained by means of the method and apparatus :described in the accompanying specificatlon and the more or less diagrammatic illustration in the drawings accompanying and forming a part of this application.

In the drawings, Fig. 1 is a broken top plan view partly in horizontal section of a furnace embodying the invention and Fig. 2 is an end elevation partly broken away looking towards the discharge end at the left of Fig. 1. V

The annealing furnace is preferably of such length and is so heated that a relative- 17 cool zone is provided through which the sheets to be annealed must pass before being subjected tothe annealing temperature and in which thesheets are preliminarily heated before being subjected to the final annealing temperature. As desired, the furnace may be provided with a non-oxidizing or reducing atmosphere and the furnace is preferably of such a length suflicient to allow the sheets passing therethrough to be pre-heated therein, .then raised to the annealing temperature, maintained at that temperature the reguired furnace is sup- Burner openprovl'ded at sultable intervals throughout its length for accommodating the urners employed for heating the interior of the furnace chamber and these burners are preferably of the type known as surface combustion. Obviously the furnace may also be designed for employing other kinds of fuel such as coal, coke and the like. The furnace is also provided with a grate 17 for the well known purpose.

The inner surfaces of the walls 12 and 13 and roof 14 are provided with a lining 18 composed of a refractory metal such as an t alloy having a high chromlum content and capable of withstanding the heat of the fur- The walls and roofs of the furnace with relatively narrow slits or openings 19 in each endfor the entrance of sheets thereto and discharge ofsheetsfrom the furnace chamber.

areas as to prevent ingress of air to the th furnace against the furnace pressure. Each opening or passage 19 may, if desired, be normally closed by yieldingly mounted doors 21, which may be 'yieldingly pressed into closed position by any suitable mechanism, not shown.

Provision is made for rows of sheets continuously through the furnace. These sheets may be of the same or different gauge and the drawings illustrate the furnace as equipped for two such rows, each row comprising two rows of sheets and the sheets of through the furnace at any predetermined speed independent of the sheets of the other row.

The sheets are continuously moved edg wise through the furnace by mechanism provided.

passing separate furnace chamber,

openings 26 at one end one row may be conveyed and emerging from the chamber through an aligned opening 26 at the opposite end. The chains pass around associated sprocket wheels 27 mounted on supporting shafts 28 adapted to be rotated from any suitable source of power 29 through any desired reduction gear 31. At the other end of the furnace, each chain is mounted upon an associated idler sprocket'wheel 32 and adapted to pass around the associated sprocketwheels in a continuous manner.

The roller chains 22 are supported and kept in position throughout the entire length of the furnace by bearing castings 33, 34 and 35. he bearing castings 33, 34 and 35 are positioned in the respective side walls and held in position with one another by any suitable means, such as shown at 36. The side walls 12 and 13 are supported by suitable buck-stays embedded in the concrete base 15 and extended upwardly the entire height of the furnace and the bearing casting 34 is further re-enforced by suitable metal supports 37 riveted or otherwise fixed to the buck-stays 40 and extending inwardly and engaging the top of the bearing casting 34 o prevent any upward movement of this casting.

The chains 22 are provided with spaced arms 38 extending outwardly into the furnace chamber. These arms terminate in a downwardly extending arrow shaped end 39 and thereby provide projections 41 and 42 for engaging the bent edges of the sheets. The arms 38 may be integral with the links 23 or riveted, bolted, or otherwise firmly secured ereto.

It can be seen from the above that the roller chain is supported throughout the length of the furnace and is held in position by the bearing castings 33, 34 and 35. The present roller chain, which is supported and maintained in position throughout the length of the furnace, provides a sheet supporting means capale of supportin two rows of sheets and will not sag due to t e weight of the sheets during their passage through the furnace.

sheets are readily removed from th as it emerges from the furnace.

An important advantage of: the present structure is the positioning of the conveyors so as to be supported by the side walls and the particular construction of the conveyor which renders it capable of carrying through the furnace, a greater number of sheets, to be annealed and thereby reduces the cost of such sheets.

Another important advantage of the present constructionis the lining of the inner surface of the furnace with a refractory metal e conveyor the sheets are heving suithcient cherecteristics to Withstnnd the heet oi the "furnace end therehy prevent the crnching end teihng ed ot the tnetetied :troni which the side neiis ere constructed. this does not only prevent undesirehie perticies troin conning in contact with the sheets heing treeted, hut maintains the furnace pressure end increeses the iite of the furnace intense/tr hheets ot diherent gauges may he sirnuiteneousiy nnneeied hy suspending those ot one geuge trons one conveyorend those ot nnother geuge throw the other conveyor, The speed ot the conveyors vviiil then he reguieted so es to ceuse the sheets to he suhj ected to the temperature tor periods proportioned to the gnnge thereof.

Whet it cieini es new and desireto secnre by Letters iPntent is i "the conehinetion in e continuous turnece, ot e heeting cheniher, n conveyor cheniher 'ioceted on top ot one side vveii of the heating cheniher end heiovv the root thereot, n conveyor having one run thereot rnovehie through seid conveyor chninher end sheet supporting menihers carried hy said conveyor end extending 'h'om said conveyor chamber

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