US2262545A - Method and means for controlling heat treatments - Google Patents

Description

' Nov. 11, 1941. A. 06 HUU CHAN 2,252,545

METHOD AND MEANS FOR CONTROLLING HEAT TREATMENTS Filed Aug. 25, 1937 IIIIII/7l1 'lllllll.

, in an intermittent manner.

Patented Nov. 11, 1941 METHOD AND MEANS FOR CONTROLLING I HEAT TREATMENTS Andre Do Huu Chan, Sceaux, France, assignor to Socit Anonyme des Manufactures dc Glaces et Produit-s Chimiques dc Saint-Gobain,

- Chauny & Cirey, Paris, France Application August 25, 1937, Serial No. 160,921 i In France August 31, 1936 1 13 Claims.

The present invention concerns heat treatments, that is to say it finds its application in all treatments making use of a cooling or heating action or articles or substances and it has for its object to ensure ina practical manner the uniformity of cooling or of heating or, at any rate, to make the variations of temperature very gradual from one point to the other of the articles treated.

It consists in effecting theheat treatment, not

by the direct action of the source of cold or of heat on the article, but through the intermediary of members which move relatively to the article.

In other words, the invention consists in arranging between the source of cold or of heat and the article a memberforming a screen which is continuous or not, to which is imparted a movement of displacement relatively to the article in such a manner that the zone of action of each point of the screen on the article moves on the surface of the latter.

Said movement is consequently in principle a movement of displacement parallel to the surface of the article, but it should be understood that it can be combined with other movements such, for example, as movements away from or towards the screen relatively to the article.

. as extended an effect of uniformization as dea hot zone and before a cold zone of the article and consequently enables said point of the screen to take up a certain part ofthe heat of the hot zone of the article to impart it subsequently to the cooler zone. 1

In a general manner the method according to the invention therefore overcomes the lack of uniformity of the source. of cold or of heat; and

also the lack of uniformity of the article from the thermic point of view.

Screens have already been proposed and utilized which are placed between the article to be treated and the source so asto render the action of the latter uniform, but leaving the screens stationary relatively to the article in such manner that the screen itself as regards this effect of rendering the action uniform can only act 'by its conductibility. This effect is consequently limited and delayed.

The present invention, on the contrary, enables sired to be obtained, and to increase therapidity .l i The movement of the screen can obey var ouslaws according to the circumstances of the treatment. It can, for example, always be efiected in the same direction in a continuous manner or It can .be alternating, periodic, it can follow an open curve or a closed curve. It can be rectilinear or curvilinear, etc.

The effects produced by the displacement'oi the screen in the method according to the invention are multiple. I

On the one hand each point of,,the source of cold or of heat exerts its action on a greater surface of the article so that if the said source has thermic irregularities, for example an excess oi. intensity at a point, the action of said point instead of being localized on the narrow zone of the article which would correspond to a point of the screen in the fixed position and determine therein a very different temperature from that of the surrounding zones, is spread over a greater zone so that the irregularity of temperature is if not eliminatedat any rate very much decreased. On the other hand, if for any reason "the article of itself has-zones which tend to become cool or heated difierently from each other,

the mobility of the screen enables the same point of said screen to be passed successively before,

of action of the screen.

p The various characteristics and advantages of theinvention will, moreover, become clearly apparent in the course of the description of various embodiments of the invention given hereinafter by way of examples, with reference to the ac- 1 companying drawing.

.S'aid examples relate to the heat treatment of sheets of glass to which the inventionis advantageously applicable.

In said drawing:

Fig. 1 is a vertical longitudinal section of an annealing chamber.

Fig. 1a illustrates a modification of a detail shown in Fig. 1.

Fig. 2 is a transverse section taken through 22 of Fig. 1.

Fig. 3 shows in plan a modification of screens.

Fig.4 is a vertical section of a heating oven.

Fig. 5 is a diagrammatic view showing a modification of screen.

Fig. 6 is a section of an oven to which said screen is applied.

Fig. '7 is the perspective view of another screen.

Fig. 8 is a section of an oven in which a plurality of sheets are heated of which the temperature is equalized by a single screen.

Figs. 1 and 2 show a sheet of glass I conveyed in the known manner by rollers 2 into an anwhich are in contact with the outer atmosphere.

According to the invention, a movable screen 4 it is composed'of a series of metal blades 6 arranged close together, connected to each other by hinges and passing over guide and control drums 1. v

Owing to said movable screen the cooling of the sheet is made regular,in particular between the top and the bottom of the sheet and between the edges and the centre, thereby providing a considerable improvement relatively to the results obtained with the present devices for annealing a horizontal sheet.

As shown in Fig. 1 a screen will be advantageously arranged in each of the spaces which are left free b'tween the rollers; preferably the direction of displacement will be reversed in passing from one screen to the next.

It will be observed that the sheet I is in continuous movement in a direction perpendicular to that of the displacement of the screen. Consequently, the temperature is automatically made regular not only in the transverse direction but also in the longitudinal direction of the sheet, owing to the movement of the latter relatively to the screens.

In the modification'of Fig. 3 which likewise relates to the treatment of'a, sheet of glass I moving in the direction of the arrow 8 the inlayers having suflicient dimensions for the face: of the sheet I to be subjected in their entirety tc the. conjugated action of the two layers.

In Fig. 8 the oven contains a plurality of the sheets I.

The source of heat is formed by gas burners I1. The movableascreen I8, constructed for example according to one of the previously described embodiments, enables all the sheets I to be heated equally at all their points although said sheets-are placed very diiferently from each other relatively to the source of heat, and the latter, furthermore, owing to its nature, is not very uniform.

In any case the sheet or other article can be placed inany position either vertical, horizontal or inclined according to the conditions and circumstances in which the novel method is applied.

In the different applications'of the invention it may be advantageous to combine contact actions with the effects of radiation. For this purpose the screens can, for example, be provided vention is carried out by means of screens 9 in the shape of discs or rings parallel to the plane of the sheet and rotating in their plane about their centre. I

The action of .the screen by exerting itself between the middle and the edges renders the temperature of the sheet uniform.

' The examples which have just been described relate to the application of the invention to the cooling of an article such as a sheet of glass.

Varlousapplications of the invention for heating articles will now be described.

In Fig. 4 the casing of an oven is shown at I0.

A sheet to be heated, for example a. sheet of glass I, is arranged inside said oven where it is held by any appropriate means. .Electric resistances II form the sources of heat.

According to the invention, screens 4 interposed between the sheet I and the 'sources of heat II are adapted to move in the direction of the arrows f and ensure the equalization of the temperature of the sheet.

Insteadof using, as shown in Fig. 4, a screen made of plates or sheets, the screen can be with wires which come into .contact with the surface of the article to be treated; such an arrangement increases the intensity of the exchanges of heat between the screen and the article and is particularly recommendable at low temperatures for which, as it is known, the ex-' changes by simple radiation are less active than at high temperatures, the exchanges by contact being predominant. Such an arrangement is shown in Figure 1a and illustrates the application of wire bristles f on the inner surface of the movable screen 4. r

According to the applications, I can use screens made of more "or less conducting materials. In certain cases metal screens are preferable, in other cases I use refractory screens.

1. A method for rendering heat treatments uniform, consisting in transmitting the action of the source of cold or of heat to the articlesto be .treated, through the intermediary of members" forming screens, and imparting to said members a movement relatively to the article 'and independently therefrom, in such a manner that the formed by an assembly of juxtaposed cables,

I2I3, Figs. 5 and 6, controlled so as to move in directions which are reversed from one cable to the next in such a manner that said screen as a whole does not have a single direction of displacement as that of Figs. 1 and 4-while being formed of members which move individually in a continuous manner always in the same direction. In the devices of the previous figures the displacement of the elements of the screen takes place in the same direction. If it is desired that with its movement the screen should act in several directions, it suffices to form same of cables or ribbons arranged along a plurality of superposed layers, each of which moves-in different directions. For example, two layers, l5l6, Fig. 7, will be constructed, one of which moves in a certain direction andthe other in a direction at 90 relatively to the first, the aggregate of the two zone of action of each point of said members on the article moves on the surface of the latter in the direction along which its temperatures are intended to be equalized.

2. A method for rendering heat treatments uniform, consisting in transmitting the action of the source of cold or ofheat to the articles to be treated, through the intermediary of members forming screens, and imparting to said members a movement relatively to the article independently therefrom and parallel with the surface of said article, insuch a manner that the zone of action of each point of said members on the article mov es on the surface of the latter in the direction along which its temperatures are intended to be equalized.

3. A device for rendering the heat treatments of articles uniform, comprising a source of cold or of heat, a. member forming a screen between said source and the article to be treated, and means for imparting to said member a movee ment' relatively to the article to be treated in the direction along which its temperatures are intended to be' equalized but independently from said article. I 4. A device for rendering the heat treatments of articles uniform, comprising a source of cold or of heat, a member forming a screen between said source and the article to be treated, and and means for rotating one of the drums of each means for imparting to said member a movepair, the direction of rotation being different ment relatively to the article to be treated, indefor two adjacent pairs. pendently therefrom, parallel with the article 9. A device for rendering uniform the heat and in the direction along which its temperature 5 treatments of sheet articles comprising a source is intended to be equalized. of cold or of heat, a screen formed by an as- 5. A device for rendering uniform the heat sembly of juxtaposed cables located between the treatments of sheet articles, comprising a source source and the sheet, and means for imparting to of coldor of heat, a screen formed by interconsaid screen a movement relatively to the sheet,

nected metal leaves located between the source parallel with the latter and in the direction along and the sheet, and means for imparting to said which its temperature is intended to be equalized.

screen a movement relatively to said sheet; 10. A device for rendering uniform the heat parallel with the latter and in the direction along treatments of sheet articles, comprising a source which its temperature is intended to be equalized. of cold or of heat, a screen formed by an assem- 6. A device for rendering uniform the bent bly of juxtaposed cables located between the treatments of sheet articles, comprising a source source and the sheet, means for imparting to the of cold or of heat, a screen forming an endless even numbered cables a movement relatively to system located between the source and the sheet, the sheet and parallel with the latter, and means and means for imparting to the screen a movefor imparting to the odd numbered cables :3. ment relatively to said sheet, parallel with the movement in the pp direction 150 the a orelatter and in the direction along which its temsaid movement. perature is intended to be equalized. 11. A device for rendering uniform the heat 7. A device for rendering uniform the heat treatments of sheet articles, comprising a source treatments of sheets of glass, comprising two of cold or of heat, a screen formed by a disc parallel walls in contact with the outer atmose parallel to the plane of the sheet and located phere, in the space between said walls a syst between the source and the sheet, and means for, of parallel rollers arranged in mutual spaced rotating Said disc about its centerrelation and adapted. to convey sheets of glass, device rendering uniform the heat means for rotating said rollers in the same directreatments of articles, comprising a u e f tion, in each of the spaces between two succes- 001d of heat, m m f rm n a r n be- Sive rollers a pair f parallel drums, an endless tween said source and the article to be, treated,

band passing over the drums of each pair, an means for imparting to said member a movement transversely directed to the path of the sheet f relatively to the article to be treated, and flexible mung one of the drums elements carried by the movable screen and lass, and means for ro i each pain sweeping the surface of the article to be treated,

A device for rendering uniform the heat 13. lfiplant for,.the heat treatment of articles treatments of sheets of glass, comprising two f tunnel l of wlthm parallel walls in contact with the outer atmossald tunnel {mans the uncles to be phere, in the space between said walls a system treated to Elmulate 5 3 2 of parallel rollers arranged in mutual spaced 405019611 formmjg an endless mt'erposed relation and adapted to convey sheets of glass, tween the art'lckis and walls of the tunnel means for rotating said rollers in the same direcand for lmpartmg a m e the Gas between two Successive endless chain formed by the screen, in a direction, in each of the spa rollers a pair of parallel drums, an endless band perpendi to that m which the articles passing over the drums of each pair, and trans- Pimula'te witmn the tunnel versely directed to the path of the sheet of glass, N R D0 HUU CHAN-

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