US2007833A

US2007833A - Machine for drying sheet material

Info

Publication number: US2007833A
Application number: US667155A
Authority: US
Inventors: Charles B Norris
Original assignee: Reconstruction Finance Corp
Current assignee: Reconstruction Finance Corp
Priority date: 1933-04-21
Filing date: 1933-04-21
Publication date: 1935-07-09
Anticipated expiration: 1952-07-09

Description

y 1935. c. B. NORRIS MACHINE FOR DRYING SHEET MATERIAL Filed April 21. 1955 3 Sheets-Sheet l July 9, 1935. c. B. NORRIS 2,007,833

,MACHINE FOR DRYING SHEET MATERIAL Filed April 21, 1933 5 Sheets-Sheet 2 July 9, 1935.

c. B. NORRIS MACHINE FOR DRYING SHEET MATERIAL Filed A ril 21, 1933 3 Sheets-Sheet s Edema; mar/952%??? KL I Patented July 9, 1935' enrorrics MACHINE FOR DRYING SHEET MATERIAL Charles Norris, Grand Rapids, Mich assignor',

by mesma assignments; to Reconstruction Finance Corporation, a Federal corporation Application April 21,1933, Serial-Not 667,155

14 Claims.

In the manufacture of plywood wherein the: various plies are united with a synthetic resin adhesive, it is advantageous to apply the adhesive; in a liquid state and then to dry the adhesive.

It is desirable that the drying be done both' effectively and quickly. The object of the present invention is to produce a simple and novel machine. for thus drying glue sized sheets of veneer.

- shown there is an angle bard connected to every and the like. a

The various features of novelty whereby'my invention is characterized will hereinafter be pointed out with particularity in the claims; but for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description. takenin.

connection with the wherein: I -,Figure 1- is a top plan view of the machine emaccompanying drawings",

elevation of the machine, on a larger scale, only the two end portions being shown; Fig. 3 is an: end'view of the'maohine, on the same scale as Fig. 2, the middle portion being omitted; Fig. l

5 ing fluids have free access to substantially the entire surface area on both sides or faces of each:

sheet, and the currents of drying fluids being :so directed that the sheets will be carried alongiin substantially the same way as though they were passing through still air. i

The sheets to be dried can most conveniently be carried through the drying chamber while lying. on an -endless conveyor. I have therefor provided a large box-like casing or housing l closedat the top and at the sides and being sufficiently open at the, ends to permit veneers. or

the like. to be placed into the machine and removed: therefrom. Within this casing or cham-- spaced apart the. width of the machine and connected together at intervals by cross bars 4 bodying the present invention; Fig. 2 is a side The principle of my invention consists in the carrying of the sheet to be dried through a. drying" chamber where it isexposed to drying cur-. rents of air or other suitable fluids; the sheets being supported in such a manner that the drywhich, in the arrangement shown, are angle.

(or. ai -.12) f irons. The angle irons are arranged outwardly with respect to the chains. The bars iproject laterallybeyond the chains, resting at their ends upon. tracks or rails 5 and B, at least throughout the length of the upperrun of the conveyor. The

spaeebetween the twochains is also spanned by means that gives to-the conveyor the eifect of being. abroad belt or band. In the arrangement other link of each of the chains; each angle bar being welded to a, plate 7 wide as the length of alink and extendingfrom one chain to the other. Weldedor otherwise secured to each of the plates 1 is the marginal portion ofanother plate 8 which also extends across the entire width; of the conveyor andis wide enough to bridge the. gap between the plate 1 to which it is secured and the. next. adjacent plate fl. This arrangement permits the conveyor to travel around'suitable driving wheels, 9. The chains and their driving and supporting wheels-.inay be of any usual or suitable type; In the arrangement shown, the partof eachwheel that engages with its chain is octagonal in shape, each side of the octagon beingequal to the length of one of the links of thechain i The veneers sheets of which are indicated at A,. do not rest directly on the. conveyor but upon the upper edgesof thin partitions or vanes N1 welded to the angle bars and held thereby in suchpositions that they stand at right angles to the face of the conveyor. These vanes are. not only parallel with each other, but they are of .uniform height so that the upper edges of the vanes along the u-pper run of the conveyor liein the same horizontal plane. e

The front end of the-casing or housing has thereinan. opening 1-] just above the front end of the conveyor, through which opening the veneers. are inserted; The conveyor, driven, as will be hereinafter described, carries the veneer through the casing or housing to the opposite end' where the veneer-is discharged through an openingIZ." r 3 .While traveling through the casing or. housing theveneer is subjected topourrents of heated air forced through the interior of the'casing or housing in; the general direction. of the length of the vanes-on the conveyor. This air passes both aboveand below the veneers'and, where the velocity thereof is sufiicientrfor satisfactory drying, the. air will'blowthe veneer off the conveyor I toward one side of the casing Therefore, although the vanes onthe conveyor form, as it were, troughsthrough which warm air may'fiow in contact with the under faces of the veneers, while other air may flow across the upper faces of the veneers, means must be provided to keep the veneers from being blown away. I have found that the most satisfactory means for this purpose is a second endless belt-like device above and similar to the conveyor. The upper endless member consists of chains I3 and I4, similar to the chains 2 and 3, having associated therewith angle bars I5, plates l6 and I1, and vanes l8, similar to the angle bars 4, the plates 1 and 8, and the vanes of the carrier proper. The ends of the angle bars I project laterally beyond the chains, those along the lower run of the device riding on stationary rails l9 and 20, directly above the rails 5 and 6, so that the lower runs of the chains l3 and I4 are parallel to-the upper runs of the chains 2 and 3. The parts are so proportioned and adjusted that directly above each of the vanes ID on the straight portion of the upper run of the conveyor or carrier, there is a vane IS, the distance between the upper edge of each of the vanes l0 and the corresponding vane l8 being at least as great as the greatest thickness of veneer to be treated in the machine. It is not necessary that the vanes I8 touch the veneer, their purpose being to provide above each of the traveling troughs underneath a piece of veneer a corresponding inverted trough directly above the veneer. Consequently, when warm air is blown into the space between the conveyor and the upper endless member from one side of the machine, in a transverse direction, the air will be divided into a series of separate streams each flowing through its own tunnel or channel and each bounded on the sides by four vanes, two on each side, at the bottom by plates 1 and 8, and at the top by plates [6 and I1. Wherever there are sheets of veneer on the conveyor or lower belt, they divide these tunnels or channels into upper and lower sections; so that the streams of air are again divided, half of each flowing underneath the veneer and the other half across the top. The result is that the veneers lie quietly on the conveyor while it is being carried through the drying chamber, just as though they were not being subjected to strong air currents.

The air enters the right-hand side of the easing or housing, as viewed in Fig. 4, flowing in the direction of the arrow B; the rails and i9 and 6 and 5, together with the lower run of the upper endless belt and the upper run of the conveyor forming upper and lower walls of the air passage through the casing or housing. The air that first strikes the veneers remains in contact therewith across the entire width thereof; and, because it takes up moisture as fast as it can during the first part of its movement, it may be saturated before reaching the far side of the veneer and thus prevent the glue from drying evenly across the width of the veneers. I have found that, if means are provided to produce a turbulence in the air streams from the time they come in contact with the veneers, and thus permit all of the air to be effectively used to absorb moisture, this difficulty can be overcome and the glue be evenly dried. This can conveniently be accomplished by placing in the path of the main air stream, before it is divided, a bafile device extending lengthwise of the casing beside the path of travel of the veneers. In the arrangement shown, the baffle takes the form of an angle iron 22 so located that the two flanges or wings form angles of forty-five degrees with the veneers that are being dried, the plane of the veneers passing through the apex of the angle in the bar, and this apex pointing away from the veneers. Those strata of the air streams that would otherwise travel straight ahead in contact with the upper and under faces of the veneers are therefore deflected upwardly and downwardly, respectively, before they reach the veneers. By this means a disturbance or turbulence is set up in the air streams so that all parts thereof at one time or another come in contact with the faces of the veneers or, rather, with the glue on those faces.

The warm air or other drying fluid or fluids may be supplied and moved in any suitable way. In the arrangement shown, the fluid is simply re-circulated air; there being enough leakage of air at the ends of the casing or housing to cause the moisture that is taken up from the glue to escape gradually and thus leave the air in the system dry enough to effect its intended purpose. This recirculation of air may conveniently be effected by connecting the air passage through the casing or housing in a closed loop. Thus, the airmay enter the drying space or air passage in the casing or housing through a nozzle-like device 24 extending throughout the length of the upper run of the conveyor or carrier and so placed that its upper wall abuts or at least lies close to the upper rail 26, while its lower wall is similarly positioned with respect to the lower 1 rail 6. In other words, the horizontal flanges of the rails 28 and 6 in effect form continuations of the upper and lower walls of the nozzle. This nozzle is connected to and leads from a box-like structure or housing 25 beside the main casing or housing. In this box-like structure are suitable blower devices 28 that discharge into the nozzle. A C-shaped pipe 2'! is connected at one end to the box 25, passes across the top of the main casing or housing, and has its outlet end opening into the space between the rails l9 and 5, as best shown in Fig. 4. l'he cross section of the pipe or conduit 2? may conveniently be that of a rectangle one transverse dimension of which is many times as great as the other. In other words, what may be termed the width of the conduit is preferably about as great as the length of the horizontal portion of the upper run of the carrier, While the other transverse dimension need be only large enough to provide the proper cross-sectional area to permit the efficient re-circulation of the air. Within the pipe or conduit are suitable heat interchangers 28 that warm the air as it passes over them. The heat interchangers may be supplied with steam or other heating fluid that enters through a pipe 29 and leaves through a pipe 35.

The moving elements of the machine may be driven in any suitable way. The blower or blowers can conveniently be driven by a motor 32 and the endless belt-like members from a suitable variable speed drive device I have alless conveyor or carrier run over wheels 9 at the front end of the machine. These wheels are fixed to a transverse shaft 35. At the opposite end of the machine there are wheels 38 similar to the wheels 9. Likewise, the chains of the upper endless belt run over wheels 3? and 38 at the front and rear ends of the machine. wheels 36 are fixed upon a transverse shaft 39, and the wheels 3'! and 3B are fixed to transverse shafts 40 and M, respectively. On the shafts 46 and 4| are sprocket wheels 42 and 43 over which runs a sprocket chain 44. On the shaft 40 is The aoo'zgeae.

a pulley 45 and, running over this pulley and: a pulley 46 on the variable speed drive, is a; belt; The upper endless belt istherefore driven. directlyfrom the variable speed drive, The shatts M and 3% have thereon: like? gear wheels 14$ meshing with each other, so. that the endless conveyor o'rcarrier is drlven directly from the: shatt M at exactly the samelinear speed the upper endless'belt. v a

i If desired. the'lower run of eachoiithe chains of the endless conveyor or carrier may be'sup ported upon a. rai1f49 that may be: similar to the rails 61 and 5, and. theupper' run of each oi! the chains of the upper endless belt may be 15 1 supported by and run along a rail 50 similar to the: rails I 9 and 20 r With my improved machine 'I am able: thor oughlyto: dry glue-"sized veneers rapidly and. withno other laborthan that required: to lay the sheets, one at a time, on the. endlesszconveyor' at the: inlet end of the: machine, By supporting: the veneers on thenarrow edges of: thin; vanes, I am able not only to distribute the flowing air in such a manner that. the veneerstare' notblown about, but also to dry both sides at the/same time, wherebothzfaces of the veneer are glue sized. Bydryingquickly and making the drying process a continuous one, large quantities of: veneers. may be dried. in a single machine; and, furthermore, along with proper temperature: control, the-drying ofv synthetic resin glues carr be effected without objectionable .change in the."advancement of the glues.

While I have illustrated and described with particularity only a single preferred; form: of my invention, I do.- not desire to be: limitedtto the. exact structural details. thus: illustrated and .dc.- scribed; but intend. to cover all forms-1 and are rangernents which. come within the. definitions:- of. my invention constituting.theappended claims.

"lclaiinz a "1 In a. machine of the character described" two parallelmembers located one: above thei other and spaced a short distance aparhsaidi members being movable in the same direction and at the:

same speed, each of. saidr members having wide,

deep, closelyspaced troughs extending transversely across the same on the side toward the other member, and means for causing; currents of a drying fluid to flow through said. troughs in contact with veneers or the like lying on the lower member. I l Y 2. In a machine of the character described, two parallel members located one above the other and spaced a short distance apart to permit veneers or the like to be placed between them, said members being movable in the same direction and at the same speed, each of saidmembers having wide, deep, closely spaced troughs extending transversely across the sameon the side toward the other member, the troughs in the upper memher being inverted and approximately registering with the troughs in the other member, and means for causing currents of a drying fluid to flow through said troughs above.

3. In a machine of the character described, two parallel members located one above the other and spaced a short distance apart to permit veneers or the like to be placed between them, said members. being movable in the same direction and at the same speed, each of said members having wide, deep, closely spaced troughs extending transversely across the same on the side toward the other member, and means for causing turbulent currents of a drying fluid to flow through. said troughs in contact with: the veneers ta cause drying fluid to flow through said troughs and across the top of: sheets of veneer or thelike resting. on the carrier, and means above the carrier to cause the flow across the top of the said sheets to be divided. into streams similar to and. flbwlngin the same. directions as the streams through said troughs. l

5.. In machine of the character described, a horizontal, movable carrier having in the top Widadeep troughs arranged close together and extending. transversely across the same, means to: cause a drying fluid to flow through said, troughs-t beneath sheetsfof veneer or the like resting on the carrier and also across the tops 0t such sheets, means above the carrier to cause the: flow across the top ofthe said sheets to"v be divided into streams similar to and flowing in the: same directions as the streams throughv said troughs; and means toproduce turbulence in said streams;

.6. Ina machine of .thecharacter described, two horizontal endless belts arranged one above.- the. other, the upper run: of the lower beltbeing spaced apart from parallel with the lower:

run. of the upper belt,elements-on eachl belt co"- operating with the vanes to form along each. at

said. runs a series of open-ended troughs each:

closed at three: sides and; open at; the fourth side andxat the endatransverse vanes orrandiproj'ect ing; outwardly from each of thebelts, the: com

binect height of two vanes, one on each: bolt, be-- In a machine of. the character described,

two horizontal endless belts arranged one above the other,. the upper-run of thelower: belt being spaced, apart from and parallel: with. the lower run: 0d the upper belt, vanes; extending crosswise of each: belt. and: projecting outwardly therefrom atrightlangles thereto, elements oneach belt eooperating with the vanes to form along each ot said? runs. a series of open-ended. troughs each closed at three sides and open at the fourth side and at the ends, the vanes on the upper run of the lower belt registering with the corresponding vanes on the lower run of the upper belt but being spaced apart far enough to permit sheets of veneer or the like to be laid on the upper edges of the vanes along the upper run of'the lower belt, and means for causing a drying fluid to flow through the space between said runs of the belt in the direction of the length of said vanes.

8. In a machine of the character described, two horizontal endless belts arranged one above the other, the upper run of the lower belt being spaced apart from and parallel with the lower run of the upper belt, elements on each belt cooperating with the vanes to form along each of said runs a series of open-ended troughs each closed at three sides and open at the fourth side and at the ends, vanes extending crosswise of each belt and projecting outwardly therefrom at right angles thereto, the thickness of each vane being only a very small fraction of the distance between consecutive vanes the combined height of two vanes, one on each belt, being less than the distance between the aforesaid runs to permit sheets of veneer or the like to be laid on and be supported by the upper edges of the vanes along the upper run of the lower belt, and means for causing a drying fluid to flow through the space between said runs of the belts in the direction of the length of said vanes.

9. In amachine of the character described, two horizontal endless belts arranged one above the other, the upper run of the lower belt being spaced'apart from and parallel with the lower run of the upper belt, elements on each belt operating with the vanes to form along each of said runs a series of open-ended troughs each closed at three sides and open at the fourth side and at the ends, transverse vanes on and projecting outwardly from each of the belts, the thickness of each vane being only a very small fraction of the distance between consecutive vanes the combined height of two vanes one on each belt, being less than the distance between the aforesaid runs to permit sheets of veneer or the like to be laid on and be supported by the upper edges of the vanes along the upper run of the lower belt, and means for causing turbulent streams of drying fluid to flow crosswise through the space between said runs.

10. In a machine of the character described, a housing, two endless movable belts extending lengthwise through the housing one above the other, the upper run of the lower belt and the lower run of the upper belt being horizontal and parallel and, in eiIect, imperforate, conduit means connecting the space between said runs at one side of the housing to the same space at the opposite side of the housing, blower means in said conduit means to cause a circulation of air through said conduit means and said space,-

and means on said belts to supportsheets of veneer or the like about midway between said runs with substantially the entire surface of each exposed and at the same time divide the air flowing through said space into numerous individual streams flowing crosswise of the housing.

11. In a machine of the character described, a housing, two endless movable belts extending lengthwise through the housing one above the other, the upper run of the lower belt and the lower runof the upper belt being horizontal and parallel and, in effect, imperforate, conduit means connecting the space between said runs at one side of the housing to the same space at the opposite side of the housing, blower means in said conduit means to cause a circulation of air through said conduit means and said space, means to heat said air, and means on said belts to support sheets of veneer or the like about midway between said runs with substantially the entire surface of each exposed and at the same time divide the air flowing through said space into numerous individual streams flowing crosswise of the housing.

12. In a machine of the character described, two parallel members located one above the other and spaced a short distance apart to permit wood veneers to be positioned between the same and be supported on the lower member, each of said members being shaped to form with such veneers parallel open-ended tunnels, means for moving said members at the same speed transversely of the direction of length of said tunnels, and means for causing currents of a drying fluid to flow through said tunnels.

13. In a machine of the character described, two parallel members located one above the other and spaced a short distance apart to permit wood veneers to be positioned between the same and be supported on the lower member, each of said members being shaped to form with such veneers parallel open-ended tunnels, means for moving said members at the same speed transversely of the direction of length of said tunnels, means for causing drying fluids to flow through said tunnels, and means to set up a turbulence in such fluids upon entering the tunnels.

14. In a machine of the character described, two horizontal endless belts arranged one above the other, the upper run of the lower belt being spaced apart from and parallel with the lower run of the upper belt, transverse vanes on and projecting outwardly from each of the belts, the vanes on each belt forming with the latter a series of open-ended troughs closed on three sides and extending across the belt, the combined height of two vanes, one on each belt, being less than the distance between the aforesaid runs to permit sheets of veneer or the like to be supported by the upper edges of the vanes along the upper run of the lower belt, and means to cause a drying fluid to flow through said troughs both above and below said sheets.

CHARLES E. NORRIS.