US2217452A

US2217452A - Controlled cooling in a heat treating process

Info

Publication number: US2217452A
Application number: US158923A
Authority: US
Inventors: Clarence E Peck
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1937-08-13
Filing date: 1937-08-13
Publication date: 1940-10-08
Anticipated expiration: 1957-10-08

Description

c. E. PECK 2,217,452 CONTROLLED COOLING IN A HEA'I TREATINGPROCESS Get. 8, 1940.

Filed Aug. 15, 1937 .4 Sheets-Sheet 1 I INVENTOR C/arence E Pea/r.

ATTORNEY Oct. 8, 1940. c, E, P cK CONTROLLED COOLING IN A. HEAT TREATING PROCESS Filed Aug. 13, 1937 4 Sheets-Sheet 2 7 INVENTOR I Clarence E Peck.

l In" "I l l l A TTORNEY W! TNESSES Oct. 8, 1940. c, EcK

qmwnoumb COOLING IN A HEAT TREATING PROCESS Filed Aug. 13, 1937 4 Sheets-Sheet 3 11v VENTOR Clarence E Peck.

A'TTOR NE y Oct. 3, 1940. Q E, PE K 2,217,452

CONTROLLED COOLING IN A HEAT TREATING PROCESS Filed Aug.- 15, 1937- 4 Shoets-Sheet 4 d I HE fla m)..

WITNESSES 11v VENTOR Wfifl. 6% I C/aren'ce E Peck.

BY g i A TTOR/VEY Patented Oct. 8 1940 CONTROLLED COOLING In A HEAT TREATING rnocass Clarence E. Peck, Wilkinsburg, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a

Pennsylvania corporation of 1 Application August 13', 1937, Serial No. 158,923

Claims.

This application, is a continuation-in-part of my application Serial No. 113,196, filed November 28, 1936.

My invention relates to industrial furnaces and 5 more particularly to a cooling structure for cooling continuous sheets or the like, and controlled cooling in a heat treating process.

In the process of heat treating, particularly in the case of normalizing sheet steel and the like, the type of grain structure obtained depends upon the rate of cooling of the steel after it has reached the normalizing temperature. This grain structure will be very fine for a rapid rate, of cooling and will correspondingly increase in size with a decrease in the rate of cooling. It is, therefore, obvious that an operator may obtain any desired grain structure by merely adjusting the rate of cooling to correspond with the desired grain structure. Accordingly, it is an object of my invention to provide a method of and'means for cooling, andcontrolling and regulating the rate of cooling the hot material as it passes through the cooling structure.

Likewise, in the process of heat treating it becomes necessary to regulate the atmosphere in which the material is placed. By utilizing a protective atmosphere the accumulation of scale upon the niaterialis eliminated, whereupon the surface remains unchanged during the process, thus eliminating the necessity of pickling. It is, therefore, a further object of my invention to provide means for maintaining the presence of a protective atmosphere within the cooling structure and for preventing excessive escape of such atmosphere.

A further object of my invention is to provide means whereby the cooled sheet or the like may be delivered to the open air without permitting such air to enter into the cooling structure to contaminate the protective atmosphere therein.

A further object of my invention is to provide means for circulating the protective atmos- A further object of my invention is to provide means for creating a high velocity of atmosphere with respect to the charge and for preventing any tendency of hot and cold gases to stratify with 55. respect to the charge.

A further object of my invention is to provide means for sealing the various sections of the cooling structure to prevent any appreciable amount of the protective atmosphere from escaping therefrom and for maintaining the sealing 5 medium at a satisfactory low temperature.

A'further object of my invention is to provide means for sealing an entrance to such structure while a charge is being passed through such opening.

Other objects of my invention will either be V pointed out specifically in the course of the following description of one form of a system embodying my invention; or will be apparent fro such description.

In practicing my invention, I provide a con- I tinuouscooling structurewith means for attaching it to furnaces or similar structures, a plurality of rolls for conveying the charge throughthe structure, a plurality of fans located either on the top or the bottom or both, to circulate the protective gas which is within the structure and to absorb the heat from the charge as it passes therethrough, a plurality of baffles to direct the now of the atmosphere within the structure, and a plurality of pipes for absorbing the heat from the atmosphere, a heat absorbing medium circulating through such pipes to absorb the heat thereof and conductit to the outside of said cooling structure.

I also provide a plurality of curtaining devices located upon the last section for preventing the protective atmosphere from leaving, or the air from entering the structure as the charge is delivered therefrom.

In the accompanying sheets of drawings:

Figure 1 is a fragmentary elevational view of the complete cooling structure with a sectional view of an intermediate section and the end sections,

Fig. 21s a side elevational 'view of an intermediate section, p t

Fig. 3 is a sectional view taken along line 'III-III of the intermediate section" shown in Fi Fig. 4 is a sectional view taken along line IYIV of Fig. 3,

Fig. 5 is an exaggerated view showing the re-'- lationship between the fan guards and the bailies as taken along line V--V of Fig. 4,

Fig.- 6 is a plan view of the cooling pipes as attached to the top cover.

Fig; '7 is a sectional view taken along lin VII-VII of Fig. 1,

Figs. 8 and 9 are sectionalviews taken along lines VIII-NIH and IX-IX, respectively, of Fig. '7, and

Figs. 10, 11 and 12 are elevational views of the curtain as attached to the exterior curtaining device.

Referring to Fig. 1, I show a continuous cooling structure I I composed of a plurality of end sections l and 2 and one or more intermediate sections 3. The end or adapter section I may be constructed in any suitable manner so that the cooling structure H may be attached to any desirable heating or normalizing furnace or structure 5 without losing the protective atmosphere therein. However, it is preferred that the adapter section I be attached to the furnace by means of a flange 60. The flange 60 is rigidly attached to section I, preferably by welding, and may be rigidly attached to the furnace 5, either permanently or removably, to form a gas-tight junction between the cooling structure II and the furnace 5.

The end section 2 has located thereon a plurality of curtaining devices l3 and I4 which prevent the protective gas atmosphere within the cooling furnace from escaping to the air or the air from entering therein. An intermediate section 3 is shown, which is similar in construction to the other sections which are partially shown. A plurality of fans 25 may be located within the intermediate section 3. The exact location of these fans may differ in each succeeding section, namely; the first section may have two fans located upon the top and one upon the bottom of the structure, the next having one fan located upon the top and two upon the bottom, and each succeeding pair of sections may follow this sequence.

A plurality of rolls 52 are located within the furnace in such a manner as to convey a continuous sheet of steel or the like through the cooling structure from the normalizing furnace 5 out through the curtaining device l4 to the outside of the structure. These rolls 52 are driven in any suitable manner, such as by the sprocket and chain mechanisms 5| (Fig. 2), which may be operated by a suitable drivev shaft 50 which is driven .by any primary power source. This chain and sprocket gearing device may be located at one point upon each section, driving The cooling structure proper is contractiblyand expandibly mounted upon flash-plates 19 by means of an under-structure l1 and I8 and suitable rollers 2|. The flash-plates l9 are permanently embedded upon a suitable foundation 20. By mounting the continuous cooling structure l I upon the foundation in such a flexible manner, the danger of rupturing said structure due to the expansion and contraction thereof is overcome.

Referring to Fig. 2 andFig. 3, I show another intermediate section 3a. This section is similar in construction to section 3 shown in Fig. 1, except that in the section 3 one fan with blades 3| is placed upon the top and two fans having blades 32 are located upon the bottom thereof, while in this section 3a, as shown in Fig. 2, two fans 25 are located upon the top and. one upon the bottom.

Located within the sections 3 and 3a, as shown in Figs. 3, 4 and 5, are a plurality of rolls 52,

- tions.

two sections thereof upon the bottom of sectiona plurality of baiiles 28 and 21, a plurality of cooling pipes 28 and their necessary fittings 29 and the fan structures 25. The baflles 21 have a main or horizontalportion substantially parallel to the top and

bottom walls

24 and 24a, respectively, of the sections 3 or 3a and side portions which are substantially parallel to the side walls of the structure or perpendicular to the planes of the top and bottom walls of said sec- The cooling pipes 28 are in four sections,

3a and two sections upon the underside of the removable top 34 of section an. These pipes 28' are located within a space between the main or horizontal portion of baffles 21 and the top or bottom walls of the section 3 or 3a in such a manner as to permit the free circulation of the atmosphere through such space and about the cooling pipes. Baffles 26 are circular in shape and may completely circumscribe the fans 25 and may be attached to the top and bottom baflles 21 in any desirable manner. By locating the fans within the baflles 26, it is possible to force the atmosphere within the cooling structure through a predescribed orbit.

As illustrated in Fig. 3, the bailles 21 are attached to the top 34 by means of small angular brackets 4| and are spaced therefrom so that the cooling pipes 28 may be inserted within the space between baflie 21 and the top 34 or bottom 35. The fans 25 are attached to a shaft 38 having attached at the other end thereof a pulley 31 which may be operatively associated with a driving motor 60 by means of a belt 39 and a pulley 38. Each fan is, accordingly, operated as a separate unit, this permitting the operator to adjust the speed thereof to any desirable value.

Additional bailies 36 may be placed within the sections of the cooling structure, as shown in Figs, 3, 4 and 5, in such a manner as to divide the sections longitudinally into small zones. The baflles 36 may be attached to the bafiles 21 in any suitable manner. These bafiles 36 may extend substantially vertically downwardly and upwardly from the main or horizontal portions of baffles 21, located at the top and bottom of said sections, to within approximately 3 inches .of the plane of the charge, substantially as shown in Figs. 3, 4 and 5. By having the'bafiles 36 extending substantially vertically from the horizontal portions of bailies 21, and dividing the sections 3 or 3a longitudinally into small zones, such baftles 36 will be substantially perpendicular to top, bottom, and side walls of the sections 3 or 311, as well as the side portions of the bafile 21.

Accordingly, the bafiles 36, may act as guards for the fans. by preventing the charge from buckling up or deforming in such a manner as to hit Y them. as well as directing the flow of atmosphere within the cooling structure. These baflles 36 extend transversely across the whole section where there are no fans. However, at such points where the fans are located, thebaflle's 36 extend between the vertical portions of the baille 21 and the bailies 26-which enclose the fans.

The cooling pipes 28 are grouped in a manner substantially as shown in Fig. 6, and are attached to the bottom or the top of the respective sections by means of a plurality of brackets 42.

ture may then be used when there are either one Y sired to be passed over andthrough this cooling coil and fin construction. -These cooling coilsthen absorb the heat from the charge by convection from the protective gas atmosphere which protective gas atmosphere the movement of heated atmosphere which conveys such heat from the charge to the cooling coils 28, and the absorption thereof by such coils. In addition the cooling coils 28 absorb heat from the charge by means of direct radiation of heat from the charge to the baffles 21, conduction of heat through the bailies, and radiation of such heat from the baf-- fles 21 to the cooling coils.

It is preferred that the cooling coils 28 be made 'in small sections, each section of which is attached by means of suitable fittings 29 to the outside of the cooling structure. This then makes it possible to have a different rate of cooling throughout the various portionsof the.

cooling structure, by regulating the rate of flow of the cooling medium through the correspondis either equal to or greater than the distance between pipes 41. This particular type of strucor two fans located upon that particular side of the cooling structure. This may be shown by the two fan shafts 39 located one on each side of the cooling coils between pipes 41 and by the dotted circle 30a which illustrates the position of a single fan shaft 33 when the cooling coils' are 10-.- cated upon the reverse side of said structure. It is, therefore, obvious that the same construction of cooling pipes is interchangeable between the top or bottom portions of each section and is interchangeable between alternating sections 'of the cooling structure regardless of the number of fans located upon that particular section.

- It will be observed that the tops 34 of each section are removable, as shown in Figs. 1, 2,3 and, I

temperatures within thecooling structure, to use a liquid seal such as water, oil, glycerin, etc. Because the sealing trough i and the sealing medium 6 may attain a temperature which would vaporize or boil off such sealing medium 6, a cooling coil or pipe 8 is located within the trough 1..

Any desirable cooling medium, such as water, is then circulated within this cooling pipe 8, which is immersed in the liquid seal. The presence of such a seal between the top and the cooling struc-- Y ture enables the top to be removable, as well as effecting a gas seal which prevents the protective gas atmosphere from escaping from within the cooling structure.

It will be observed that the

baflie structures

36, 26 and 21, the fans 25 with their operatively associated motors ii] and the driving

mechanisms

30, 31, 38 and 39, cooling coils 28 with their fittings 29, being attached to the top section 34,

By convection I mean the phenom maybe lifted out of the cooling structure by removing the top section 34. This then makes it 5 possible for the cooling structure to be cleaned'or I repaired whenever desired without altering or removing any portion of the main cooling structure. The lower baffles .33; 26, 21, fans 25 and cooling coils 28 with their brackets 42 being permanently attached to the main cooling structure,

may be repaired and maintained while the top section 34 and its associated parts is removed therefrom. It is, therefore, obvious that due to the liquid seal and removable top structure, the cooling structure may be servicedwith a minimum amount of effort and time, without altering or-changing any predetermined settings.

By using the liquid seals, as heretofore described, it is possible to maintain within the cooling structure aprotectivegas atmosphere, preferably partially combusted or cracked hydrocarbon gas which is non-oxidizing.- This gas may be injected\ into the cooling structure at any of several desired positions throughout the length of the cooling structure, preferably through the top.

It is preferred that the pressure of said protec-. tive gas atmosphere be sufliciently greater thanthe atmospheric pressure, so that if there should be any slight apertures within the cooling structure, the greater pressure of the protective atmosphere would then prohibit the entrance of outside air into the cooling structure.

The protective gas atmosphere may also be injected into the cooling structure by means of the pipes 22 which have a plurality of small holes drilled and located therein in such a manner as to direct the gas upon the entrance-to the first curtaining device i3. This atmospheric curtain will then aid in preventing any air from leaking through said curtaining device by maintaining the pressure on the inner side thereof at a substantially greater value than the air on the outside of said cooling structure.

The operation-of the fans which induce a high velocity and turbulent action within the circulating atmosphere causes a small pressure diiference between the outside atmosphere located at the curtaining devices and the gas within thecooling structure proper. This small pressure difierence may be sufficient to draw air in from the outside.

Accordingly, the pressure of the gas used for the gas curtain must be greater than the difference in pressure caused by the fans at the inside of the opening of the curtaining devicei3, so as to prevent the air from creeping in and contaminating the atmosphere. This increased gas pressure will then produce a tendency for the atmosphere to force its way out through the plurality of curtaining devices [3 and l4 and further prevent the ingly, as the sheet'steel or the like travels through the cooling structure from one end to the other,

it readily enters and proceeds through the-plu' rality of curtaining devices i3 forcing the. plurality of sheet asbestos guards 9 apart and forming a good line contact therewith. Thisthen produces a good seal which prohibits theprotective atmosphere from leaving and the air from entering the working portions of the cooling structure while the charge is passing through the curtaining devices l3.

The exterior curtaining device M, which may be attached to the cooling structure by means of the front wall H in any suitable manner, shown in Figs. 1, 7, 8 and 9, may comprise a housing 23 and a plurality of rolls l5 and I6, resiliently, mounted within such housing. The top roll [5 is biased downwardly by means of spring l2 while the bottom roll i6 is biased upwardly by spring I211. The springs i2 and Ho are rigidly attached to the housing 23 by means of tabs BI and are preferably under tension. The elongated continuous yoke members 62 and 64 connect the rolls [5 and I 6 with the springs l2 and 12a, respectively, and act as guides for keeping the rolls in line, one on top of the other. The rolls l5 and I6 may be made of any desirable material, though it is preferred that they be covered with sheet asbestos. As a charge of sheet steel or the like proceeds through the preliminary curtaining devices i3 to the exterior curtaining device M, it contacts and rides between the resiliently mounted rolls l5 and IS. The rolls l5 and 16, due to the biasing effect of the springs l2 .and Ho, ride upon the charge, forming a line contact therewith, and a further seal against the entrance of the air into the cooling structure between such rolls and the charge.

Asbestos curtains 66 prevent gas leakage and the entrance of air around the ends of the rolls l5 and I6 or over and under such rolls. The curtains 66 are formed by two sheets of asbestos as shown in Figs. 10, 11 and 12. The top sheet is attached to an angular support 68 and the bottom 1 central portion 10 thereof is folded around the roll l5, as shown in Figs. 8. and 11, and then attached to the angular support 68. The bottom sheet is wrapped around the roll l6 and attached to support 69 in a similar manner. The side flapsl2 of the respective sheets are sewed together, and then rigidly attached to the front wall 14 of the housing 23 by means of plate 16 and rivets 18. It is obvious that the curtains thus prevent the passage of air or gas about the ends and around the top or bottom 'of rolls I 5 and I6.

Due to the operation of the fans, the protective gas atmosphere is circulated invarious circular orbits, the planes of which are at approximately right angles tothe longitudinal axis of the cooling structure. The atmosphere is forced either downwardly or upwardly depending upon whether or not it will be above or below the charge until it strikes the charge whereupon it spreads out in all directions.

A large portion of the atmosphere proceeds alongthe longitudinal axis upon the surface of the charge and in so doing encounters the vertical bafiles 36, which longitudinally divide the cooling structure into small zones. These bafiles perform a dual function in respect to the protective gas atmosphere by increasing the relative velocity of the atmosphere with respect to the charge and by acting to stir the atmosphere and introduce a turbulent effect therein which eliminates any tendency for hot and cold gases to stratify with respect to the charge. v

Because of the vacuum between the vertical side baffles 21 and the side walls of the cooling structure, that portion of the atmosphere which does not travel longitudinally along the charge is drawn directly to the side and upwardly or downwardly toward the fan and the cooling coils.

That portion of the atmosphere which progresses longitudinally along the charge is then drawn to the side along an arcual path except when being interrupted in its travel by the presence of the baiiies 36. After the gas is drawn upwardly or downwardly along the side of the cooling structure, it encounters and proceeds through the cooling coils located upon the top and bottom between the horizontal portions of baffles 21 and the top and bottom walls. and 24a, which absorb the heat that has been convected or conducted from the charge by the circulating atmosphere. The cooled atmosphere is then drawn through the fan and again blown upon the moving charge to continue its travel and conduction of heat therefrom.

In the operation of ,the continuous cooling structure II, the charge of continuous sheet steel or the like is delivered from any preheating or normalizing furnace 5 into the end section I, where it rides upon and is propelled by the plu- As the charge progresses ture, the velocity of the circulating atmosphere and the rate of flow of the cooling medium within the cooling coils.

Then as the charge leaves the last of the cooling sections, it proceeds on into the last section where it encounters and traverses the plurality of various curtaining devices. These curtaining devices act as filters which permit a small amount of the protective gas atmosphere to leave the cooling structure, but preventthe admission or creeping in of the air which would contaminate the non-oxidizing protective atmosphere within the cooling structure.

It is, therefore, obvious that by means of regulating the rate of flow ofthe gas and the rate of flow of the cooling medium 'within the cooling coils, I am able to cool and to variably control the rate of cooling of a charge of continuous sheets or the like as the charge progresses through the cooling structure and while enveloped by a protective gas atmosphere. By so regulating the rate of cooling the charge, the

-length of time a particular portion thereof is within the cooling structure is also a variable factor which may be regulated at the will of the operator.

It is also obvious that I have provided a high I 1y desirable and efficient means of absorbing the heat from the charge and of conducting such heat out of the cooling structure and at the same.

1 from the spirit and scope thereof, and I desire,

therefore, that only such limitations shall be placed thereon as are imposed'by theprior art and the appended claims.

' I claim as my invention:

1. A cooling structure for cooling continuous sheets and the like having therein a protective gas atmosphere, comprising the combination of a casing having a pair of top and bottom walls,-

comprising substantially U-shaped baffles, each' having intermediate portions located substantially parallel to and at a short distance from one of the walls of said pair of walls, and baflies transverse to said walls located substantially perpendicular to said intermediate portions of the U-' shaped baflies for directing the circulation of the atmosphere upon said moving sheets, means within the casing for absorbing heat from the atmosphere, and means for conducting such ab-. sorbed heat away from the absorbing means and out of the casing.

2. A cooling structure for cooling continuous sheets and the. like having therein a protective gas atmosphere, comprising the combination of a casing having a pair of top and bottom walls, with means for moving said sheets through said casing, means comprising fans located within the casing for circulatingthe atmosphere therein whereby said atmosphere may absorb and con- 4 duct the heat from the moving sheets, means comprising substantially U-shaped bafiies, respectively having intermediate portions located substantially parallel to and at a short distance from one oi the walls of said pair of walls, and

baflles transverse to said walls located substantially perpendicular to said intermediate portions of the U-shaped baffles for directing the circulation of the atmosphere upon said moving sheets,

means comprising pipes located within the casing spectively having intermediate portions located substantially parallel to and at a short distance 'from one of the walls of said pair of walls, and

bailies transverse to said walls located substantially perpendicular to said intermediate portions of the U-shaped baiiles for directing the circulation of the atmosphere upon said moving sheets, means comprising pipes located between said intermediate portions and the said walls for absorbing heat from said atmosphere, and means one of said walls and forming a space therewith,

said intermediate portion'extending in the 'general direction of the movement of the sheets,

a 5 spaced baflies disposed transverse to said direction and depending from said baffle in proximity to but spaced slightly from the path in which said sheets move, cooling means including pipes in the said space for absorbing heat from the atmosphere and conveying it outside the casing.

5. A cooling structure for cooling continuous sheets and the like while enveloped by a protective atmosphere, said structure comprising the combination of a casing having a pair of walls including a top and a bottom wall, and having side walls, with means for moving said sheets longitudinally through said casing, means for circulating the atmosphere within the casing, means for directing the flow of atmosphere within the casing, comprising a baffle having an intermediate portion locateda short distance from one ofsaid pair of walls, said intermediate por- -tion extending in the general direction of the movement of said sheets, said baiiie also having leg portions depending vertically from a pair of opposite edges of said intermediate portion, and

tive atmosphere, said structure comprising the.- combination of a casing having a pair of walls comprising a .top and a bottom wall, and having ends, with means for moving said sheets longitudinally through said casing, means for circulating the atmosphere within the casing, means for directing the flow of atmosphere within the casing, comprising a bailie having an intermediate portion located a short distance from one of said pair of walls, said intermediate portion extending in the general direction of the movement of said sheets, said baiiie also having leg porti ns depending from a pair of opposite edges of id intermediate portion, and extending toward and in proximity tothe path in which said sheets move, said baiiie terminating short of the said ends, means within the casing for absorbing heat from the atmosphere, and means for conducting such absorbed heat away from said absorbing means and out-of the casing.

7. A cooling structure for cooling continuous sheets and the like while enveloped by a protective atmosphere said structure comprising the combination of a casing having a pair 'of walls including a top and a bottom wall, and having side walls andends, with means for moving said for circulating the atmosphere within the casing, means for directing the flow of atmosphere within the casing, comprising a'baiiie having an intermediate portion located a short distance from sheets longitudinally through said casing, means one of said pair of walls, said intermediate portion extending in' the general direction of the movement of said sheets, said baiile also having leg portions depending from a pair of opposite edges of said intermediate portion, and extending toward and in proximity to the path in which said sheets move but spaced slightly therefrom, said leg portions being spaced from said side walls, said baiiie terminating short of the said ends,

means within the casing for absorbing heat from the atmosphere, and means for conducting such and out of the casing.

8; A cooling structure for cooling continuous sheets and the like while enveloped by a protective atmosphere, said structure comprising the combination of a casing having a top and a bottom wall, with means for circulating the atmos-,

phere within the casing, means for directing the flow of atmosphere within the casing, comprising substantially, U-shaped baflies, respectively having their intermediate portions substantially parallel to and a short distance from said walls, and

their side portions vertically directed toward the ing their intermediate portions substantially par.

allel to and a short distance from said ,walls, means to move said sheets longitudinally through said casing between said intermediate portions, said baiiie's having side portions extending toward and in proximity to the path in which said sheets move but spaced slightly therefrom, means within the casing for absorbing heat from. the atmos- .-phere, and means for conducting such absorbed heat away from the absorbing means and out of the casing.

10. A cooling structure for cooling continuous sheets and the like while enveloped by a proteclating the atmosphere within the casing, means for directing the flow of atmosphere within the casing, comprising substantially U-shaped baiiles, respectively having their intermediate portions substantially parallel to and a short distance from in which said sheets move but' spaced slightly therefrom, said bafiles terminating short of said ends, means within the casing for absorbing heat from the atmosphere, and means for conducting such absorbed heat away from the absorbing means and out of the casing. I

11. Acooling structure for cooling continuous sheets and the like while enveloped by a protective atmosphere, said structure comprising the combination of a casing having a pair of walls comprising a top and a bottom wall, and having side walls, with means for moving said sheets longitudinally through said casing, means for circulating the atmosphere within said casing whereby said atmosphere may absorb and conduct away heat 'from the moving sheets, means for directing the flow of atmosphere within the casing, comprising substantially U-shaped baffles respectively having their intermediate portions located substantially parallel to and a short distance from said pair of walls, said baflies having their side portions extending toward and in proximity to but spaced from the path in which said sheets move, and spaced from said side walls,

means within the casing for absorbing heat from the atmosphere, and means for conducting such absorbed heat away from the absorbing means and out of the casing.

12. A cooling structure for cooling continuous sheets and the like while enveloped by a protective atmosphere, said structure comprising the combination of a casing having a top and a bottom wall, and having side walls, with means for moving said sheets longitudinally throughsaid casing, circulating means for circulating the atmosphere within the casing, means for directing the flow of atmosphere within the caisng, comprising substantially U-shaped baffles, respective- I! having their intermediate portions substantially parallel to and a short distance from the saip top and bottom walls, said intermediate portions having apertures, said circulating means comprising air propelling means in said apertures, said baffies also having leg portions depending from a pair of. opposite edges of said intermediate portions and extending towards and in proximity to the path in which said sheets move but spaced slightly therefrom, said leg portions being spaced from said side walls, means within the casing for absorbing heat from said atmosphere, and means for conducting such absorbed heat away from the absorbing means and out of the casing.

13. A cooling structure for cooling continuous sheets and the like while enveloped by a protective atmosphere, said structure comprising the combination of a casing having a top and a bottom wall, and having side walls, with means for moving said sheets longitudinally through said casing, circulating means for circulating the atmosphere within the casing, means for directing the how of atmosphere within the casing, comprising substantially U-shaped baflies having their intermediate portions substantially parallel to and a short distance from the said top and bottom walls, said intermediate portions having apertures, said circulating means comprising air propelling means forcing air through said apertures, said baflles also having leg portions depending from a pair of opposite edges of said intermediate portions and extending towards and in proximity to the path in which said sheets move but spaced slightly therefrom, said leg portions being spaced from said side walls, means including fluid-carrying pipes in the spaces between the said intermediate portions and said top and bottom walls, said pipes having fluid inlet and fluid outlet means outside the casing.

14. The structure of claim 12 including spaced bailles extending between said leg portions.

15. A cooling structure for cooling continuous sheets and the like, comprising, a walled casing having a removable top wall section, a baflie supported from and in spaced relation to said top wall section, cooling means comprising pipes supported on said baffle, and having pipe inlet and pipe outlet means extendingthrough said top wall section, means supported by said top wall section for circulating atmosphere in said casing, and including an air propelling means in an aperture in said baffle, said bafile including depending baflles for directing the flow of atmosphere within said casing in orbital paths passing through said cooling pipes.

. CLARENCE E. PECK.