US1952402A

US1952402A - Annealing furnace

Info

Publication number: US1952402A
Application number: US682092A
Authority: US
Inventors: Wilson Lee
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-07-25
Filing date: 1933-07-25
Publication date: 1934-03-27
Anticipated expiration: 1951-03-27

Description

March 27, 1934. 1.. wlLsoN 1,952,402

ANNEALING FURNACE Filed July 25, 1955 2 She'etS-Sheet l March 27, 1934. L. WILSON ANNEALING FURNACE Filed July 25, 1933v INV TOR ATToR N EY Patented` 27,1 1934 1,952,402 ANNEALING FUBNACE Lee Wilson, Cleveland, Ohio Application July 25, 1933, Serial No. 682,092

9 Claims.

This invention relates broadly to annealing furnaces, and more particularly to a furnace for heat treating or annealing metal sheets, strips, coils, plates, and the like, in-a controlled and non-oxidizing atmosphere. Y

The present invention aims to provide a fur nace in which the material may be efficiently heat treated or annealed by exposing the same in the furnace, free from any covering whatsoever, in an atmosphere heated by radiation and free of products of combustion or other harmful gases.

A further object of the invention is to. provide a furnace in which the material may be treated in a fraction of the time consumed under existing methods and with present structures, the.

annealing also being accomplished with the consumption of a minimum amount of fuel.

A further object is to provide individually con-` trolled heat radiating units for regulating the temperature of the furnace, as may be desired.

erence being had to the accompanying drawings,

in which- Figure 1 is a vertical cross sectional view of a furnace constructed in accordance with my lnvention, the section being taken on line A-A, Fig. 3;

Figure 2 is a vertical cross sectional view' of the removable bell or hood removed from the stationary base or foundation, a portion beingbroken away; and- Figure 3 is a section on line B-B, Fig. 1.v

The furnace is preferably composed of two principal parts- 'permanent base or foundation, and a mova le bell or muille type heating furnace.

The base is permanently and stationarily constructed on the floor level and consists of a foundation 1 of common brick upon which is superimposed the base 2, the latter being made of an appropriate insulating material. This construction provides a raised platform, rectangular in top plan view and wh'ose plane dimensions are greater than the sheets 3 to be annealed. AEncircling said base and at a spaced distance therefrom is a U-shaped channel 4, designed to contain oil, water, molten lead, or other appropriate sealing agent. l

The movable bell or mullle type furnace herein described is also rectangular in shape and consists of two 'side walls 5a, two end walls 5b, and a roof or crown 5c, all of refractory-material, the bell being housed in ametal casing 6. The inside dimensions of the furnace exceed' the corresponding dimensions of the elevated platform, as shown in Fig. 1, the lower ends of said furnace being shaped to correspond with the base 2, and

-the lowermost edge of the furnace resting upon the floor level about the foundation when in operating position.

' A plurality of vertically extending tubes '7 are positioned along the two parallel side walls 51,. the upper ends thereof being reduced somewhat in diameter and protrude outwardly through the crown 5, dampers 8 being present in each of said tubes: Said tubes rI are maintained in rigid relation interiorly of the furnace by means of hooks 9 which embrace said tubes, the Shanks of said hooks extending outwardly through the side walls of the furnace and being fastened by nuts.

The lower ends of said vtubes 'l are connected to and supported by elbow joints l0, the opposite right angle end of each elbow being connectedto a sleeve 11 which extends in length throughout the thickness of the furnace walls, terminat-I ing exteriorly of the furnace wall. Each of said sleeves 11 is composed of a hollow tubular casing lined with refractory or insulating material. As shown in the drawings, the elbows l0 rest upon a ledge 12 formed interiorly of the furnace wall adjacent the bottom.

Firing into each of the sleeves 11, which latter, in conjunction with the elbows 10, serve as combustion tunnels, is an individual gas or oil burner 13, supplied with fuel through the manifolds 14 carried by the furnace, as by means of the brackl ets 15. A valve 16 is provided with each burner whereby the operation of the latter may be regulated. y

In practice, the material 3, as steel sheets, to

. bev-treated is stacked upon the raised base 2 and thel furnace is then lifted and placed over and about the base 2 by means of an overhead lifting crane, supporting eyes 17 being provided at opposite corners on the furnace to facilitate moving.

When lowered about the base 2, the outwardly and downwardly extending annular skirt 18,

lief

lthe inside of thefurnace'from the atmosphere,

as depicted in Fig. 1. The burners 13 are then ignited and the burning of the fuel'in the vsleeves 11 and elbows 10 results, of course, in the crea-- 1y fired unta such time es the material is brought .up to the required temperature and there maintained for a predetermined period of time.v f

when the heating cycle is eomp1eted, the burners are closed and the furnace'may'be cooled by passing air through the tubes, or itmay be cooled solely by loss Yof heat through radiation, after which the furnace is lifted and removed to permit removal of the material, after which the operation may berepeated. e I 4 y Upright pins 20 may be statlonarily xed to the oor and project upwardlytherefrom at opposite sides of the base so as' to receive thereabout loops or eyes 19 extending outwardly from the furnace, this arrangement affording means for guiding the latter to correct seating position with respect tothebase. e From the above description it will be noted that the furnace described provides a structure in which annealing may take place efficiently. economically and with considerable saving of time. It will alsobe observed that the construction presented aords an annealing chamber in which substantial variations in temperature at different points of the furnaceis eliminated. Under exi isting methods, the top of the furnace or the pack is always hotter than the bottom, this difference at times amounting to as muchv as 500 F. This condition produces sheets. that are not uniform in anneal, many being over-annealed and 'many having to be returned for further annealing. One reason for the diierenceintemperature in the top and bottom of the pack or furnace is due to.

the concentration of weight or mass that must be heated adjacent the bottom. Inbox annealthe sheet supporting plate-like tray, ball rollers, and sand seal are located at the bottom, and these elements alonel lcontribute one-fourth to one-half of the total mass to be heated to annealing temperature. Too, as is well. known in the art, it is difficult to force and maintain heat adjacent the bottom of any furnace.

Due to the fact that the ame fired from the yburners 13 of the herein described structure is While I havev herein described the furnace as being of rectangular-shape, it will be understood that other and different shapes may more readily be adapted for certain purposes. For instance, a circular shape may be utilized for the annealing of coils and the like. Y f

It is thought that the construction and operation of the furnace and the function. of its various elementswill readily be understood from the yinterfree v f foregoing description. Further, while I have described the invention more or less in detail, it will be understood that I do not limit myself to Adetails of construction and arra ement of parts` except as may be required by4 a air interpretation of the terms of the appended'claims.

What is claimed isze y l. In an annealing furnace, a base, a bell side and end walls and a roof movably mounted on the base, a series of vertical heating tubes in vthe bell disposed along each side wall ofthe latter andhaving upper open ends extending through the roof and having lateral portions at ,theirI lower ends ppening through the side walls at the lower parts of the latter, and a manifold connected to each side wall of the bell and having a series of burners, one for each tube, which burners are in register with the open ends of the lateral portions of the tubes,'the upper ends of the tubes being attenuated and having dampers disposed exteriorlof the roof,

2. In an annealing'furnace, abase, a bell having side and end walls and a roof movably mounted on the base, aV series of vertical heating tubes in the-bell disposed along each side wall of the latter and: having` upper open ends extending through the roof and having lateral portions at their lower ends opening through the side walls at the lower parts of the latter, and a manifold connected to each side wall of the bell and having a series of burners one for each tube which burners are ,in register with the open ends of the lateral portions of the tubes.

3. In an annealing furnace, abase, a bell having side and end walls and a roof cooperable with the base, a series of vertical heating tubes in the bell. disposed along each side wall of the latter andv having upper open ends extending through the roof and having lateral portions at their lower ends opening through the side walls at the lower parts of the latter, and a series of burners one for each tube which burners are in register with the open ends of the lateral portions of the tubes., v

- 4. In an annealing furnace, a base, a bell cooperable with the base, a series 'of vertical heating tubes in the bell disposed along opposite sides of thel latter and extending substantially throughout the height of the bell, and having portions extending through said sides of the bell, and means for supplying heat to each of said portions of the tubes.

5. In an annealing furnace, a base, a bell cooperable withv the base, a series of vertical heating tubes in the bell disposed along opposite sides of the latter and extending substantially throughout the height of the bell, and having portions extending through said sides of the bell, and a burner for each tube in register with said portions thereof.

6.*In a heat treating furnace, a base, a bell located over said base, ya series of vertical heating tubes inthe bell disposed along each side wall of the latter and having vtheir upper ends extending exteriorly of the bell adjacent the roof of the latter, and a series of gaseous fuel burners, one foreach tube, whereby each tube may be individually fired.

.7. In a furnace, the combination with a'heatling chamber and a hearth therefor, a plurality distance above said hearth, and a gaseous fuel burner located in the lower end of each of said tubes whereby each tube may be independently red. i

8. In a furnace, a base, a movable bell cooperof the tubes.

9. In a furnace, a heating chamber, a series of vertically disposed heat-radiating tubes arranged along the walls of said heating chamber, and having their lower portions extending exteriorly of the furnace adjacent -the hearth, a gaseous ,fuel burner for each tube in register with each of said portions whereby controlled heat v treating temperatures may beindividually intro. duced into each of said tubes.

WILSON.