US1507665A - Method of furnace operation - Google Patents

Description

Sept. 9, 1924.

.H. H. CLARK METHOD OF FURNACE OPERATION Filed Oct. 26. 1921 j a E j.

Patented Sept. 9, 1924.

UNITED STATES HORACE H. CLARK, OF O'AK PARK, ILLINOIS.

METHOD OF FURNACE OPERATION.

Application filed October 26, 1921. Serial No. 510,551.

To all whom it may concern: I

Be it known that 1, Homer. H. CLARK, a ,citizen of the United States, residing at Oak Park, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Methods of Furnace Operation, of which the following is a specification.

My invention relates to a method of furnace operation whereby the materials may be melted or otherwise subjected to heat treatment in a furnace atmosphere that is non-oxidizing or inert and immobile, and without the expense and complication of a hood or enclosure within the furnace to protect the articles from the immediate results of the combustion through which the furnace temperature is developed.

This application relates to an improvement upon the method of furnace operation described in my application Serial No. 403,001, filed August 12, 1920.

One object of my invention is to provide a method of furnace operation wherein the articles to be treated will not only be protected from direct action of furnace heating flame or violent convection of furnace gases which would result from continuing the combustion during the treatment, but in which the products of combustion are largely or wholly removed from the furnace prior.

to the introduction of the goods.

A further object of my invention is to pro:

vide an improvement in the method of treatment which consists in directly heating the urnace by means of gas or other suitable fuel, interrupting the supply of fuel, and

subjecting the articles to be heated to the heat of the furnace only during the period that the fuel supply is cut off, by which improvement products of combustion will be applied to the furnace more effectively, under better control, and therefore more economically than has heretofore been proposed.

In carrying out my invention, I provide a furnace having an open chamber therein, which is spaced from the walls of the furnace proper, and which space may be filled with some heat insulating medium to prevent too rapid heat losses within the furnace chamber. Fuel is supplied to the furnace chamber directly and burned therein, and I prefer to employ gas or oil as fuel. The gas or oil is supplied to suitable burners disstood by charging'into the furnace at a plurality of symmetrically disposed points around the walls thereof, and substantially at the level of the furnace floor, and means are provided for regulating the supply of fuel. The bottom of the chamber may be provided with supports, on which the articles to be subjected to the heat are supported, to permit the heat to engage as great a portion of the surface of the articles as maybe found de sirable. The door of the furnace opens up the heat treating chamber substantially down to the level of the floor, and preferably throughout the transverse section of the chamber so that when combustion is arrested and the door is opened to-introduce the goods to be treated, the furnace automatically scavenges itself by the inrush of relatively cool atmosphere directly over the floor of the furnace, with displacement of the products of combustion upwardly and outwardly by the inrushing air.

My invention will be more fully underreference to the accompanying drawings, wherein- Figure 1 is a top plan view. partially in section, showing a furnace constructed in accordance with the preferred embodiment of my invention.

Figure 2 is a front elevation of the furnace of Figure 1; and,

Figure 3 is a vertical section taken in the plane of line 3-3 of Figure 1.

Referring to the drawings, the furnace of my invention includes a furnace chamber designated by reference character A, and

which is defined by side walls 5 and 6, bottom 7, and arched roof 8.' Surrounding the chamber A, and spaced therefrom is an enclosing structure comprising walls 9 and 10, and arched roof 11, the relation of the parts being such as to define a space B between the furnace chamber A and the surrounding structure. If desirable, suitable heat insulating material may be inserted in the space B. The front end of the chamber A has a door 12 here shown as being hinged at 13 to one of the side walls, the drawings showing the hinges as being on wall 6, and a latch 14, or other suitable fastening device being fixed to the door to permit the same to be opened and closed. The method of mounting the door is to be taken as merely typical of any means for mounting a door in movable relation to the front end of the chamber A, but it is to be noted that the chamber A and the corresponding walls 9' the cham r A.

{door corresponds in dimensions to substantially the entire sectional area of said chamber, so that when opened the air circulation through the chamber can take place directly over the bottom of the chamber, so that no pockets'nor-spaces remain in which to itrap product's -of combustion and interiere" with complete scavenging of the cham- Fuel burners 15 extend through the side walls 5 and 6 and the back walls of the and 10 of the enclosing structure and are arranged to burn the fuel Within the chamber A or otherwise insure the presence of products of combustion in cgmplete contact with the confines of said chamber. These burners are adapted for connection to a source of fuel supply by means not shown, but which may be of any well known form. The fuel I prefer to employ is of a liquid or gaseous form. The inner ends of the burners are shown arranged so that the discharge therefrom may be within the chamber A near the bottom 7 thereof. It is preferable that the burners be arranged near the bottom. Extending upwardly from the top of the chamber through the arched tops 8 and 11 are outlets 16 for the escape of the products of combustion, and these outlets may be closed by suitable dampers or valves if desired. On the bottom 7 of the chamber, at suitable intervals, are provided supports or standards 17, on which the articles to be heated are placed.

The enclosing structure may be tied together by suitable upright supports 18, which in the drawings are shown as channels, and which are connected to the top and bottom by bolts 19 and 20. I 7

The operation of my invention is as follows:

Fuel is introduced into and ignited within the burners15 or otherwise manipulated to develo products of combustion within It is understood that a sufiicient amount of air or other gas is introduced through the burners to perfect combustion. When my method is used for annealmg, the chamber-A is supplied with the fuel a ength of'time sufficient to heat the same to a temperature sufiicientlyl high for annealing purposes, and which temperature is approximately 1800 F. When the desired temperature has been reached, which may be ascertained by any well known means, the

fuel suppl is interrupted or cut oil, whereupon the cor 12 is opened with consequent scavenging of the chamber A of the products of combustion, and the articles to be heated are placed in the chamberon the supports '17. The articles under treatment are permitted to remain in the chamber until the treatment is completed. Whereupon the perature has been reached, the fuel supply is again interrupted and another lot of arti- .cles to be treated are placed in the chamber and the cycle continued as long as desired.

An advantage of my invention is that'the fuel consumption is cut down enormously and the cost greatly reduced. Another advantage is that the furnace necessary in carrying out my invention consists of nothing but a chamber with a surrounding wall, whereas a mufile furnace is much more complicated and requires frequent and expensive repairs. Further advantages are that the goods are not affected by products of combustion or by violent heat waves incident to convection thereof.

A still further advantage is that the articles being treated are very evenly heated in a quiet atmosphere, out of contact with any impinging flame.

For ascertaining the temperature within chamber A, any instrument may be used. ,I

have found that a pyrometer may be successfully employed, as by such an instrument the temperature within the chamber may be readily observed at all times.

The furnace bperation herein described will be found to be of particular advantage in annealing articles which it is desired to especially protect against oxidation, such, for instance, as annealing metal sheets in the production of tin plate; annealing wire to remove hardness in the process of draw-. ing it; malleablizing castings, &c. It may be evident to those skilled in the art that many changes could be made in the detailed construction of the parts which are described without departing from the I spirit and scope of my invention.

I claim:

1. A method of subjecting metals, refractory materials, and the like to high temperatures, which consists in heating a furnace chamber until a desired temperature is ob-- tai'ned, stopping the .source of heat opening the chamber to atmosphere down to the floor of the chamber, placing 'the temperature approximately that to which the metal is to be subjected, then "discon tinuingthe supply of fuel to the chamber opening substantially the entiretransverse area of the chamber to atmosphere and thereby, scavenging products of combustion therefrom, introducmg thereinto' the material to be treated, tightly closing the chamber, and leaving the material to the'action of radiant heat from the walls of the chamber.

' 3. The process of subjecting to high temperature effects in inert and immobile environment metals and other materials of high heat resisting capacity, which consists in discharging heating medium immediately over the floor of a furnace chamber until the walls thereof acquire a temperature approximately that to which the metal is to be subjected, then discontinuing the supply of heating medium to the chamber opening the chamber to atmosphere down'to the floor thereof, introducing thereinto the material to be treated, tightly closing the chamber, and leaving the material to the action of radiant heat from the walls of the chamber; delivery of heating medium to the furnace chamber being renewed after completion of. the treatment of the material and its removal from said chamber, before introducing a a successive charge of material,

' thereby maintaining the required temperaout impairing the immobile condition of the chamber dur ng the heat treatment.

4. A method of furnace operation for treatment of metals and other materials of high heat resisting capacity and the like at high temperatures, which consists in.

heating a furnace chamber into which the articles to be treated are to' be placeed by the vdelivery of heating medium substantially parallel to and immediately over the floor of such chamber, and continuing the same until apredetermined temperature is attained, stopping the source of heat opening substantially the entire transverse area of the chamber to atmosphere, immediately placing the articles to be treated within and closing said chamber and after suitable time withdrawing said articles, again applying heat to said chamber to restore the former temperature thereof for the reception of another lot of articles to be treated and controlling the temperature of the chamber sothat at the time the fuel supply is cut ofi the temperature is never in excess of that desirable for treatment of the particular articles to be-treated.

Signed at Chicago, Illinois, this 14th day of October, 1921.

Homer: H. cram;

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