US2507274A

US2507274A - Furnace

Info

Publication number: US2507274A
Application number: US723766A
Authority: US
Inventors: Earnest D Sevenich
Original assignee: Cold Metal Products Co
Current assignee: Cold Metal Products Co
Priority date: 1947-01-23
Filing date: 1947-01-23
Publication date: 1950-05-09
Anticipated expiration: 1967-05-09

Description

May 9, 1950 E. D. ISEVENICH FURNACE Filed Jan. 25, 1947 INVENTOR Patented May 9, 1950 UN lT-ED STAT ES QFFlCE 2,507,274-

FURNAGE;

Earnest D. Sevenic'h; Youngstown; ohm; assignor to The Cold Metal Products'cbmpany, Younge twn, 0hio; a corporatinn ofi Ohio Application. January 23, 1941, SerialNo.v 72327.66"

( Cll 263- -7 T 4-Claims." 1?

This invention relates to furnaces and heating methods, particularly furnaces for heating material, as, for example, annealingfurn-aces, and methods of heat treating (e. g;', annealing) material. It has to do with furnaces in which and methods in accordance with which. a charge'is advanced relatively to. a series of heating means whereby. the charge is subjected successively to the action of the respective heating means. In certain of its aspects the invention is concerned with-furnaces of the type havinga material support and a hood over the support, the heating: or heat treatment being carried on continuously or progressively during relative movement between the material and the hood, and with methods of heating or heat treating material byyuse of furnaces of that type.

It has heretofore been known to disposematerial to be heated on an elongated material support and move the support beneath a stationary hood of le'sslength' than the support'toheat the material as it advances. In furnaces of'the' type used for such a procedure the elongated'material support may be straight or curved; for example, it may be arcuate or even circular, and the hood isofcourse shaped to conform to the shape of the material support but is of smaller dimension inthe direction of its length. than the support. The words elongated and length as herein used apply to material supports-and hoods of various shapes, even" circular or arcuate, the length or direction of elongation of a circular or arcuate support or hood being the direction along the arc.

For purposes of explanation and illustration the invention will be described asembodied in a heat treating furnace having a generally circular material support and an'arcuate hood of less than 360 over the support. Furnaces of this general type are disclosed in copending applications Serial- No.-497,523, now Patent No; 2,4171063; and Serial No. 629,085, later abandoned. In thefur naces of those applications the arcuatehood'or heating chamber of less than" 360" is stationary and the circular material support moves therein; The charge to be heat treated, as, for'example, coils of metal strip; is placed upon'the material support or hearth at intervals therealong and as the hearth moves beneath the hood burners disposedzin series at opposite sides'of the hood heat the charge. The 'heat'treatment is efiecte'dby predetermining' the amount of heatsupplied by the r spective burnersto the charge'at'various points alongthe pathpi'the'charge:

t is desirable to be able to predeterminewith substantial" accuracy the" temperature" of the charge being heat-treated in a? furnace of the type above referred to at each point along'the path of the chargeiduringt'he heat treatment, i. e., during preheating;soaking; slow cooling and rapid cooling. Accurate 'predetermin'ation" of the temperature 'of' the charge'at particulanpoims in the furnace is difiicult due to the factv that the hood longitudinallyopen'" and temperature effect's, either heatingorfcooling; from one zonein the furna'ce'may be'felt in unpredictable magnttude at'other points or'zones longitudinally're-f moved "therefrom: This" maybe due to various factors such asd'rafts, variations'in outside tern perature, variations in fuel or burner adjustment, etc;

I provide a furnace and a heating method over coming-the disadvantages above referred to; According *to my heating method material to be heated is disposed in a travelable" compartment, the compartment is moved" successively into sitions in which certain of" a-series of heating means supply heat to the material and the amount of; heat supplied-by the-respective heating means" is predetermined whereby to subject the material "to-desired temperatures as it advances. My method-is especially well adapted for the heat treatment ofc'oils' of metal strip or the like. A coil-or the like maybe disposed in a-travelable compartment;- the compartment maybeadvanced intermittently and'brought to rest successively iii positions in which certain of a seri'es'of burners are" directed to discharge into the compartment general-1y tangentially ofthe coil o'rthe like to supplied by" therespective burners may be predeterminedw'hereby"'to subject the coil or the like-to desired temperatures as' it advances. Burners may bedisposed in opposed relationship to discharge from opposite sides into the'compartment; The-compartment may be advanced inter"- mitten'tly and broughtto rest successively positions in which opposed burners di'schargefrom opposite side'sinto the compartment" generally tangentially of the material.

I further provide"- a furnace comprising a sesies ofheating means and a: compartment adapt= ed to-contain material to be heated trave'lable relatively"to-the-heatingi means so"that the respectiveheating means successively heat material disposed in the compartment." The heating means are preferably 'burn'ers arranged so that as the compartment travels theb'urners are-successive'ly'directedthereinto; Desirablythebumer-s l'are inrr opposed "series;groups lasy for *exam support adapted respectively to contain material to be heated, the respective heating means being adapted successively to heat material in the respective compartments as the support moves relatively to the hood. The heating means preferably comprise opposed series of burners arranged at intervals along the hood and the elongated material support desirably has thereon partition means cooperating with the hood .to provide segregated compartments on the support adapted respectively to contain material to be heated, successive groups of opposed burners being adapted successively to heat material in the respective compartments as the support moves relatively to the hood.

Provision is preferably made for the discharge from the burners to swirl around the material in the compartments. discharge into a compartment eccentrically thereof to cause the collective discharge from the burners to swirl around the material in the compartment. The compartment is also preferably shaped to assist in bringing about swirling action of the discharge from the burners.

.Other details, objects and advantages of the invention will become apparent as the following description of a present preferred embodiment thereof and a present preferred method of practicing the same proceeds. In'the accompanying drawing I have shown a present preferred embodiment of the invention and have illustrated a present preferred method of practicing the same in which the figure is a fragmentary horizontal cross-sectional view through the heatin chamber and portions of the material support of a rotating annular hearth annealing furnace, the section being taken just above coils which are shown as being heat treated in the furnace.

Since the furnace is of the type fully disclosed in said copending applications it is unnecessary to show it in detail, the invention being fully illustrated in the single figure. There is provided a circular material support or hearth 2 adapted to turn within a stationary hood 3. The hearth is travelable within the hood, being advanced by any suitable mechanism such, for example, as concentric series of rollers underlying the hearth at least some of which are driven to advance the hearth. The hood has spaced generally vertical side walls, the inner side wall being designated 4 and the outer side Wall 5. The hood also has a top or roof arch which is not shown in the drawing but which extends between the side walls 4 and 5 at their upper extremities and overlies the hearth and the charges disposed thereon to close the furnace at the top. The side walls 4 and 5 of the hood may be sealed to the traveling hearth by any suitable means, as, for example, sand or water seals.

, The hearth is provided with longitudinally spaced partition walls 6 which are mounted thereon and are of such shape so as to substan- Desirably opposed burners tially fill the hood transversely. In other words, the partition walls 6 cooperate with the hood to provide segregated compartments 1 on the hearth adapted respectively to contain material to be heated. A coil of metal strip 8 is shown in each of the compartments 1.

An inner series of burners 9 and an outer series of burners H? are provided in the walls 4 and 5 respectively of the hood for heating the material disposed in the compartments 1 as the hearth travels within the hood. The inner and outer burners are arranged in groups or generally opposed pairs so that when the compartments are in predetermined positions one inner burner and one outer burner will discharge into each compartment. This is shown in the drawing. The burners are let through the inner and outer walls 4 and 5 respectively at an angle to the radial direction and generally opposed burners are disposed relatively to each other so that they cooperatively discharge into a compartment when the compartment is predeterminately positioned with respect thereto so as to cause the collective discharge to swirl around the coil in the compartment. The burners may discharge at a level below the level of the coils so that the discharge therefrom swirls around the coils and also rises whereby a very effective heating of the coils is brought about. The swirling of the discharge from the burners is assisted by the shape of the partition walls 6. Each such wall as shown flares out in both directions at both ends so that there are no corners within the compartments and hence there is no substantial tendency to interfere with continuous swirling movement of the gases therein.

While the hearth may be advanced continuously it is ordinarily preferable to advance it intermittently, stopping it with a compartment disposed to receive the discharge from opposed burners so as to create therein a swirling mas of heating gases as above described.

The heat supplied by each burner is predetermined so that the material being heat treated may be subjected to rather accurate temperature control as it progresses through the furnace. The burners may be controlled manually or automatically. Desirably they are controlled so that each charge as it progresses through the furnace is first preheated, then soaked, then slowly cooled and then rapidly cooled.

While I have shown and described a present preferred embodiment of the invention and a present preferred method of practicing the same, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

I claim:

1. In a furnace comprising a movable hearth, a hood enclosing a space over said hearth, and walls on the hearth extendin transversely of the hood to form an enclosure in which material may be heated when the hearth reaches a predetermined position relative to the hood, the improvement comprising burners set in the hood and opening into said enclosure to project flames into said enclosure, each of said burners being positioned adjacent one of said walls with the central axis of the burner extending toward said adjacent wall, whereby a swirling motion is imparted to the flames and heated gases in order to heat material in the enclosure with speed and uniformity.

2. In a furnace comprising a movable hearth,

a hood enclosing a space over said hearth, and walls on the hearth extending transversely of the hood to form an enclosure in which material may be heated when the hearth reaches a predetermined position relative to the hood, the improvement comprising burners set in the hood and opening into said enclosure to project flames into said enclosure, each of said burners being positioned adjacent one of said walls with the central axis of the burner extending toward said adjacent wall, and said walls each having a portion adjacent said hood curving toward the adjacent burner, whereby a swirling motion is imparted to the flames and heated gases in order to heat material in the enclosure with speed and uniformity.

3. In a furnace comprising a movable hearth, a hood enclosing a space over said hearth, and walls on the hearth extending transversely of the hood to form an enclosure, in which material may be heated when the hearth reaches a predetermined position relative to the hood, the improvement comprising burners set in the hood and opening into said enclosure to project flames into said enclosure, said burners being positioned diagonally across the hearth from each other in the enclosure and each of said burners being adjacent one of said walls with the central axis of the burner extending toward said adjacent wall, whereby a swirling motion is imparted to the flames and heated gases in order to heat material in the enclosure with speed and uniformity.

4. In a furnace comprising a movable hearth, a hood enclosing a space over said hearth, and walls on the hearth extending transversely of 6 the hood to form a series of enclosures in which material may be heated when the hearth reaches a predetermined position relative to the hood, the improvement comprising burners set in the hood and opening into said enclosures to project flames into said enclosures, said burners being positioned diagonally across the hearth from each other in each enclosure and each of said burners being positioned adjacent one of said Walls with the central axis of the burner extending toward said adjacent wall, and said walls each having curved portions adjacent the hood on each side of the hearth to form rounded corners in the enclosures, whereby a swirling motion is imparted to the flames and heated gases in order to heat material in the enclosures with speed and uniformity.

EARNEST D. SEVENICI-I.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,362,296 Hagan et a1. Dec. 14, 1920 1,617,955 Kutchka Feb. 15, 1927 2,049,950 Dixon et a1. Aug. 4, 1936 2,191,438 Breeler Feb. 27, 1940 2,231,956 Schwier Feb. 18, 1941 2,296,791 Keener et a1 Sept. 22, 1942 FOREIGN PATENTS Number Country Date 273,894 Italy May 5, 1930