CA1043728A - Method and apparatus for floatation conveyance of strip materials - Google Patents
Method and apparatus for floatation conveyance of strip materialsInfo
- Publication number
- CA1043728A CA1043728A CA267,851A CA267851A CA1043728A CA 1043728 A CA1043728 A CA 1043728A CA 267851 A CA267851 A CA 267851A CA 1043728 A CA1043728 A CA 1043728A
- Authority
- CA
- Canada
- Prior art keywords
- curved
- plenum
- nozzle
- nozzles
- strip
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B13/00—Machines and apparatus for drying fabrics, fibres, yarns, or other materials in long lengths, with progressive movement
- F26B13/10—Arrangements for feeding, heating or supporting materials; Controlling movement, tension or position of materials
- F26B13/101—Supporting materials without tension, e.g. on or between foraminous belts
- F26B13/104—Supporting materials without tension, e.g. on or between foraminous belts supported by fluid jets only; Fluid blowing arrangements for flotation dryers, e.g. coanda nozzles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H23/00—Registering, tensioning, smoothing or guiding webs
- B65H23/04—Registering, tensioning, smoothing or guiding webs longitudinally
- B65H23/24—Registering, tensioning, smoothing or guiding webs longitudinally by fluid action, e.g. to retard the running web
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2406/00—Means using fluid
- B65H2406/10—Means using fluid made only for exhausting gaseous medium
- B65H2406/11—Means using fluid made only for exhausting gaseous medium producing fluidised bed
- B65H2406/112—Means using fluid made only for exhausting gaseous medium producing fluidised bed for handling material along preferably rectilinear path, e.g. nozzle bed for web
Abstract
METHOD AND APPARATUS FOR FLOATATION
CONVEYANCE OF STRIP MATERIALS
Abstract of the Disclosure A method and apparatus is provided to convey materials in strip form by air pressure floatation. Plenums are provided along the path of floatation to alternately create positive and negative air pressure support areas which induce a wave-like conveying motion to the strip.
CONVEYANCE OF STRIP MATERIALS
Abstract of the Disclosure A method and apparatus is provided to convey materials in strip form by air pressure floatation. Plenums are provided along the path of floatation to alternately create positive and negative air pressure support areas which induce a wave-like conveying motion to the strip.
Description
Disclosure Known methods for floatation guidance of material webs or strips such as textiles, paper, plastic, metal or the like generally are divided between techniques for support-ing heavy strips and techniques for supporting light strips.
In heavy strip floatation, systems are available with high lifting capacity essentially achieved by the establishment of gas cushions or pillows between an air nozzle system and the material. ~Iowèver, the jet forces acting normally upon the material are so great that such an application for light weight strips,and in particular foils, is not feasibleO To support light weight material strips, nozzle systems are employed whose gas jets are to a large extent tangentially directed toward the material. In this manner, the vector of the jet impulse acting perpendicularly to the light weight strip material can be kept relatively small, ~hereby avoiding excessive vaulting of the material. ~ever-theless, with a system ~mploying tangential jet forces there is a tendency for the strip to flutter, requiring special precautions to be taken in the case of very light strips.
For instance, in the West German patent art, DT-OS 1 954 880 discloses a method in which the gas jet . q ,~
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comes from a nozzle arranged at right angles to the strip and is then deflected by a profiled surface element to direct the gas flow at a very small distance from the surface to be treated, such as in the order of 1 mm. ThP
steady guidance of the strip is essentially determined by the accurate dimensioning of the nozzle slots and by proper coordination of the dimensions of the profiled ~urface element to the nozzle slots. With such a small clearance between the strip and the nozzle, unserviceable for many applications, ~ `
10 small changes in the shape and/or width of the nozzle slot ;
have a considerable effect on the strip.
West German DT-OS 1 774 126 discloses a nozzle system in which nozzle ribs in the area facing the material web are formed in the proflle of an airfoil wing. In addition to the high cost of manufacturing this kind of nozzle rib, because of the small clearance between the strip and the nozzle system, this construction has the further disadvantage that a steady ~;
and flutter free floating guidance is not obtainable with a unilateral blast.
Finally, from West German DT-OS 1 938 529 a device -is known for the guidance of a moving strip which consists es~entially of an air nozzle with the cross section o~ a flat rectangular channel from which aix is discharged in the direc-tion of the goods and sweeps tangentially over a venturi surface arranged behind the nozzle. The vertical clearances of the nozzle duct slots are in this construction limited to relatively sma~l values, such as 0.76 cm maximumO This is disadvantageous for the usual application, because in the case of such small slots the usually desired high heat transfer capacity as well as a suf~icient carrying capacity can be achieved only with .
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relatively high air velocities which in return require a highly efficient air impeller means. Also in the case of this nozzle system the disadvantages already mentioned above are inherent since the clearance between the strip and the venturi surface is very small. It is also not possible to construct the nozzle with a venturi surface which has a .
greater clearance from the strip than the boundary of the nozzle channel facing the material web, whereby the distance between strip and venturi surface would be enlarged, since with a greater clearance a carrying capacity no longer exists.
It can therefore be established that the essential disadvantage of the nozzle systems described hereinabove, as well as other prior art nozzle systems not discussed here in detail, for the floating guidance of strips of light material lies in the fact that, for the desired steady supporting behavior of the strip, the gas jet discharged tangentially to the web has to be guided in itQ immediate proximity by means --- - o a guide surface which has a smooth, rounaed shape or that of an airfoil wing profile. The smal:L clearance required between strip and guide surface excludes the application of these known methods in many fields, particularly in view of the high cost of fabrication of precision airfoil guides.
According to a broad aspect, the invention relates to an apparatus for jet flotation conveyance of strip materialst the improvement in flotation means comprising: a plenum ~ -adapted to receive a pressurized gas therein; said plenum having a pair of spaced apart side members; a top flat member spaced intermediate said side members and spaced apart therefrom to define a pair of nozzles therebetween; one edge of said top member being curved downwardly~ the top edge of the side member adjacent said top member curved edge extending upwardly and curved inwardly to project over said top member at an acute ~ : , t ~
angle thereto to define an aperture parallel to and greater than the width o the adjacent nozzle; a spoiler exterior of said plenum between said nozzles; the top edye of the other of said side members being curved outwardly away from said top plate and then extending to form an acute angle with said other side portion; and a pair of plates secured to the~
underside of said top member and projecting downwardly therefrom and parallel to said nozzles; the bottom edges of said plates being curved inwardly.
It is therefore an object of this invention to provide a method and apparatus for flotation of light weight materials in which the disadvantages of the above described prior art are overcome.
It is a particular object of this invention to provida a light weight material flotation system in which thin sensitive webs or strips can be steadily guided for long distances.
It is another object of this invention to provide a :, ' ,'' ,~
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material floatation system in which a tangential flow of gas is interrupted beneath a small clearance of a light weight matexial wherein a zone of high pressure is produced.
It is another object of this invention to provide a light weight material floatation system in which plenums may be positioned on either side of the material or on both sides of the material.
It is another object of this invention to provide a material floatation system wherein thin sensitive strips or webs may be supported by nozzles at a greater distance from the material than prior art systems.
It is another object of this invention to provide a material ~loatation system advantageously utilizing a zone of high pressure ollowed by a zone of low pressure.
It is another o~ject of this invention to provide a material floatation system which induces a wave type motion in a strip material wherein undesirable~canoeing of the strip material is diminished or elimin ted. ~ -It is another object o~ this invention to provide a material floatation system in which a plane anterior nozzle is arranged parallel to the strip being conveyed and a guide surface is provided upwind of the anterior nozzle wherein, by considerable widening of the cross section between the nozzle and the guide surface, detachment of the tangential flow of gas from the nozzle is achieved by virtue of the inclination of the guide surface.
It is another object of the invention to provide a material floatation system in which jet nozzles can be con-structed for considerably less cost than a prior art guide surface in the shape of an airfoil wing profile.
- 4 _ ~ '7~J
It is another object of the invention to provide a ~ -material floatation system in which very high heat transfer coefficients can be achieved by the emplo~ment of spoilers to provide high mono~ellular turbulence of the jet stream used for material floatation.
It is another object of the invention to provide a material floatation system in which jet or mechanical spoilers may be employed to increase monocellular turbulence of gas beneath the material being floated.
It is ano~her object of the invention to provide a material ~loatation system in which a jet stream spoiler is ~
shiftable to vary the zone of higher pressure beneath the ~ -material, whereby the lifting capacity clearance relatlonship of the system may be accurately adjusted.
It is another object of the invention to provide a material floatation system in which an adjus~able spoiler makes possible the use of inexpensivè mass produced nozzles which are readily adjusted by said spoiler. `
With the foregoing and other objects and features of ~;~
the invention which will become evident from a reading of this specification, the invention consists of certain novel features o design and arrangement as illustrated in the ac~ompanying drawings, and particularly pointed out in the appended clalms, ~-it being understood that various changes in the form, pro-portion, size and minor details of the invention may be :- .
made without departing from the spirit, or sacrificing any of the advantages of the invention~
For the purpose of facilitating an understa~ding of the invention, there i8 illustrated in the ac~ompanying draw-ings a preferred embodiment thereof~ from an inspec~ion of -,: . ' ' ~ ' ' :
which when considered in connection with the following descrip-tion, the invention, its mode of construction, assembly and application and many of its advantages, will be readily understood.
Reference is now made to the drawings in which the same characters of reference are employed to indic~te corresponding or similar parts throughout the several Figures of the drawings, in which: .
FIGURE 1 is a curve in which lifting capacity is plotted against material clearance in a preferred embodiment of the invention;
FIGURE 2 comprises a plurality of curves in which floatation pressures are plotted against strip longitudinal travel;
FIGURE 3 is an elevational view in section of a pre-ferred embodiment of the inventionJ and, FIGURE 4 is a perspective view of the preferred embodi-ment of the invention also shown in section in FIGURE 3. :.-' ' ; `
. .' :' . .
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Reference will now be made to the drawings in greater deta~l~ In FIGURE 1 is shown a curve in accordance with the invention graphically illustrating material lifting capacity along the vertical coordinate versus material clearance along the horizontal coordinate. It will be seen that the resultant force acting upon the material is a ~unction of the distance of the material from the nozzles measured in millimeters along the horizontal coordinate. The force-distance parameters of FIGURE 1 i~L~L ~ 7 ~
are met by the present invention with the plenum and nozzle system shown in FIGU~ES 3 and 4, wherein a plenum 10 includes a base plate 12 and vertical side plates 14. vertically spaced apart from bottom plate 12 and parallel ~hereto is a top plate 1, which in turn is spaced apart from side plates 14 to define transverse nozzle slots 9 and 11. End plate 13, shown partially in section in FIGURE 4, encloses one end of plenum 10, and the opposite end is enclosed with end plate 13a and duct work 13b connected to a bloweL,not shown. According to the 10 representation in FIGURE 3, nozzle 9 is formed by the curved -edge lb of the top plate 1 and a curved elongation of the left side plate 14. Thereby is produced a guide surface 3 acting as ~ -a capping which extends over the curved edge lb. The guide ;
surface 3 is inclined against the top plate 1 at an angle 15 between 10 and 30 from the horizontal. The radius of sur- ;
~ace 3 is between 30 and 50 mm, from which extends a straight portion appxoximately 10 to 30 mm in length. curved edge lb is rounded off on its front edge with a radius between 5 and 15 mm. Thereby is produced a slot-shaped nozzle orifice with a width between 2mm and 16mm.
Top plate 1 is completely flat and parallel to the material web 13 which is conveyed from left to right, as shown by tne arrow in FIGURE 3. On the top plate 1 is a spoiler 7 which can be formed, for instance, by an angle iron whose leg 7b is slidably fastened to top plate 1. ~he other leg 7a axtends upwardly normal to top plate 1, toward the material web 13 and extends transversely to the traveling direction -of the web 13, and is equal in width to top plate 1 between ;
end plates 13 and 13a. In tha preferred embodiment of the invention, the distance of the spoiler 7 from curved edge lb ;' ~ " ~ ~: , .
. . .
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is between 40 to 100 mm. The spoiler 7 can be shifted in the direction of the web travel in order to harmonize the zone of over pre~sure and that of under pressure, as still shall be explained. For this purpose closeable slots 8 can be provided in the top plate 1 in which the spoiler 7 is fixed for instance by bolts and nuts 8a. In lieu of a mechanical spoiler 7, a jet spoiler may be used wherein a plurality of transversely arrayed apertures 8b may be formed in top plate 1.
As seen in the travel direction of the web another nozzle aperture 11 is provided behind the spoiler 7 which is formed by the reax straight edge la of the top plate 1 and the curved front edge of a diffuser sheet 5. The width of the rear nozzle il is between 2 mm and 16 mm. The distance of the highest point 5a of the diffuser sheet 5 from the material web 13 is less than the distance of the top plate 1 from the material web 13. Departing from point 5a the distance of the diffuser sheet 5 from web 13 increases, since the diffuser sheet extends at a small angle from the horizontal in the direction of the base 12.
For better control of lateral chargin~ of the plenum 10 with the gas, guide baffles 16 are provided heneath nozzle slots g and 11. For this purpose flanges 15 and 15a are pro-vided to project downwardly from top plate l adjacent the nozzle slots 9 and 11, respectively. Between these 1anges 15 and 15a and t~e lateral sur~aces 14 o~ the plenum 10 are ;
located the individual guide baffles 16 which are formed by ~mall plates curved toward end pLate 13 in their lower portions.
The guide baffles 16 are set up in series in the nozzle clearances 9, ll perpendicularly ~o the lateral sUrfaCeS 14 of the plenum 10.
- i .
. , . `
.
In heavy strip floatation, systems are available with high lifting capacity essentially achieved by the establishment of gas cushions or pillows between an air nozzle system and the material. ~Iowèver, the jet forces acting normally upon the material are so great that such an application for light weight strips,and in particular foils, is not feasibleO To support light weight material strips, nozzle systems are employed whose gas jets are to a large extent tangentially directed toward the material. In this manner, the vector of the jet impulse acting perpendicularly to the light weight strip material can be kept relatively small, ~hereby avoiding excessive vaulting of the material. ~ever-theless, with a system ~mploying tangential jet forces there is a tendency for the strip to flutter, requiring special precautions to be taken in the case of very light strips.
For instance, in the West German patent art, DT-OS 1 954 880 discloses a method in which the gas jet . q ,~
~'~
.
.. . .
;. :
.
,. ... . . .
: `, . ~ , ~0~3~
comes from a nozzle arranged at right angles to the strip and is then deflected by a profiled surface element to direct the gas flow at a very small distance from the surface to be treated, such as in the order of 1 mm. ThP
steady guidance of the strip is essentially determined by the accurate dimensioning of the nozzle slots and by proper coordination of the dimensions of the profiled ~urface element to the nozzle slots. With such a small clearance between the strip and the nozzle, unserviceable for many applications, ~ `
10 small changes in the shape and/or width of the nozzle slot ;
have a considerable effect on the strip.
West German DT-OS 1 774 126 discloses a nozzle system in which nozzle ribs in the area facing the material web are formed in the proflle of an airfoil wing. In addition to the high cost of manufacturing this kind of nozzle rib, because of the small clearance between the strip and the nozzle system, this construction has the further disadvantage that a steady ~;
and flutter free floating guidance is not obtainable with a unilateral blast.
Finally, from West German DT-OS 1 938 529 a device -is known for the guidance of a moving strip which consists es~entially of an air nozzle with the cross section o~ a flat rectangular channel from which aix is discharged in the direc-tion of the goods and sweeps tangentially over a venturi surface arranged behind the nozzle. The vertical clearances of the nozzle duct slots are in this construction limited to relatively sma~l values, such as 0.76 cm maximumO This is disadvantageous for the usual application, because in the case of such small slots the usually desired high heat transfer capacity as well as a suf~icient carrying capacity can be achieved only with .
- ` :. .
3~
relatively high air velocities which in return require a highly efficient air impeller means. Also in the case of this nozzle system the disadvantages already mentioned above are inherent since the clearance between the strip and the venturi surface is very small. It is also not possible to construct the nozzle with a venturi surface which has a .
greater clearance from the strip than the boundary of the nozzle channel facing the material web, whereby the distance between strip and venturi surface would be enlarged, since with a greater clearance a carrying capacity no longer exists.
It can therefore be established that the essential disadvantage of the nozzle systems described hereinabove, as well as other prior art nozzle systems not discussed here in detail, for the floating guidance of strips of light material lies in the fact that, for the desired steady supporting behavior of the strip, the gas jet discharged tangentially to the web has to be guided in itQ immediate proximity by means --- - o a guide surface which has a smooth, rounaed shape or that of an airfoil wing profile. The smal:L clearance required between strip and guide surface excludes the application of these known methods in many fields, particularly in view of the high cost of fabrication of precision airfoil guides.
According to a broad aspect, the invention relates to an apparatus for jet flotation conveyance of strip materialst the improvement in flotation means comprising: a plenum ~ -adapted to receive a pressurized gas therein; said plenum having a pair of spaced apart side members; a top flat member spaced intermediate said side members and spaced apart therefrom to define a pair of nozzles therebetween; one edge of said top member being curved downwardly~ the top edge of the side member adjacent said top member curved edge extending upwardly and curved inwardly to project over said top member at an acute ~ : , t ~
angle thereto to define an aperture parallel to and greater than the width o the adjacent nozzle; a spoiler exterior of said plenum between said nozzles; the top edye of the other of said side members being curved outwardly away from said top plate and then extending to form an acute angle with said other side portion; and a pair of plates secured to the~
underside of said top member and projecting downwardly therefrom and parallel to said nozzles; the bottom edges of said plates being curved inwardly.
It is therefore an object of this invention to provide a method and apparatus for flotation of light weight materials in which the disadvantages of the above described prior art are overcome.
It is a particular object of this invention to provida a light weight material flotation system in which thin sensitive webs or strips can be steadily guided for long distances.
It is another object of this invention to provide a :, ' ,'' ,~
,,p~, .
:: , . ..
. . .
. .. : . . . . .
:
: .: , . . . .
.: . :. .
.
3;~
material floatation system in which a tangential flow of gas is interrupted beneath a small clearance of a light weight matexial wherein a zone of high pressure is produced.
It is another object of this invention to provide a light weight material floatation system in which plenums may be positioned on either side of the material or on both sides of the material.
It is another object of this invention to provide a material floatation system wherein thin sensitive strips or webs may be supported by nozzles at a greater distance from the material than prior art systems.
It is another object of this invention to provide a material ~loatation system advantageously utilizing a zone of high pressure ollowed by a zone of low pressure.
It is another o~ject of this invention to provide a material floatation system which induces a wave type motion in a strip material wherein undesirable~canoeing of the strip material is diminished or elimin ted. ~ -It is another object o~ this invention to provide a material floatation system in which a plane anterior nozzle is arranged parallel to the strip being conveyed and a guide surface is provided upwind of the anterior nozzle wherein, by considerable widening of the cross section between the nozzle and the guide surface, detachment of the tangential flow of gas from the nozzle is achieved by virtue of the inclination of the guide surface.
It is another object of the invention to provide a material floatation system in which jet nozzles can be con-structed for considerably less cost than a prior art guide surface in the shape of an airfoil wing profile.
- 4 _ ~ '7~J
It is another object of the invention to provide a ~ -material floatation system in which very high heat transfer coefficients can be achieved by the emplo~ment of spoilers to provide high mono~ellular turbulence of the jet stream used for material floatation.
It is another object of the invention to provide a material floatation system in which jet or mechanical spoilers may be employed to increase monocellular turbulence of gas beneath the material being floated.
It is ano~her object of the invention to provide a material ~loatation system in which a jet stream spoiler is ~
shiftable to vary the zone of higher pressure beneath the ~ -material, whereby the lifting capacity clearance relatlonship of the system may be accurately adjusted.
It is another object of the invention to provide a material floatation system in which an adjus~able spoiler makes possible the use of inexpensivè mass produced nozzles which are readily adjusted by said spoiler. `
With the foregoing and other objects and features of ~;~
the invention which will become evident from a reading of this specification, the invention consists of certain novel features o design and arrangement as illustrated in the ac~ompanying drawings, and particularly pointed out in the appended clalms, ~-it being understood that various changes in the form, pro-portion, size and minor details of the invention may be :- .
made without departing from the spirit, or sacrificing any of the advantages of the invention~
For the purpose of facilitating an understa~ding of the invention, there i8 illustrated in the ac~ompanying draw-ings a preferred embodiment thereof~ from an inspec~ion of -,: . ' ' ~ ' ' :
which when considered in connection with the following descrip-tion, the invention, its mode of construction, assembly and application and many of its advantages, will be readily understood.
Reference is now made to the drawings in which the same characters of reference are employed to indic~te corresponding or similar parts throughout the several Figures of the drawings, in which: .
FIGURE 1 is a curve in which lifting capacity is plotted against material clearance in a preferred embodiment of the invention;
FIGURE 2 comprises a plurality of curves in which floatation pressures are plotted against strip longitudinal travel;
FIGURE 3 is an elevational view in section of a pre-ferred embodiment of the inventionJ and, FIGURE 4 is a perspective view of the preferred embodi-ment of the invention also shown in section in FIGURE 3. :.-' ' ; `
. .' :' . .
: `
Reference will now be made to the drawings in greater deta~l~ In FIGURE 1 is shown a curve in accordance with the invention graphically illustrating material lifting capacity along the vertical coordinate versus material clearance along the horizontal coordinate. It will be seen that the resultant force acting upon the material is a ~unction of the distance of the material from the nozzles measured in millimeters along the horizontal coordinate. The force-distance parameters of FIGURE 1 i~L~L ~ 7 ~
are met by the present invention with the plenum and nozzle system shown in FIGU~ES 3 and 4, wherein a plenum 10 includes a base plate 12 and vertical side plates 14. vertically spaced apart from bottom plate 12 and parallel ~hereto is a top plate 1, which in turn is spaced apart from side plates 14 to define transverse nozzle slots 9 and 11. End plate 13, shown partially in section in FIGURE 4, encloses one end of plenum 10, and the opposite end is enclosed with end plate 13a and duct work 13b connected to a bloweL,not shown. According to the 10 representation in FIGURE 3, nozzle 9 is formed by the curved -edge lb of the top plate 1 and a curved elongation of the left side plate 14. Thereby is produced a guide surface 3 acting as ~ -a capping which extends over the curved edge lb. The guide ;
surface 3 is inclined against the top plate 1 at an angle 15 between 10 and 30 from the horizontal. The radius of sur- ;
~ace 3 is between 30 and 50 mm, from which extends a straight portion appxoximately 10 to 30 mm in length. curved edge lb is rounded off on its front edge with a radius between 5 and 15 mm. Thereby is produced a slot-shaped nozzle orifice with a width between 2mm and 16mm.
Top plate 1 is completely flat and parallel to the material web 13 which is conveyed from left to right, as shown by tne arrow in FIGURE 3. On the top plate 1 is a spoiler 7 which can be formed, for instance, by an angle iron whose leg 7b is slidably fastened to top plate 1. ~he other leg 7a axtends upwardly normal to top plate 1, toward the material web 13 and extends transversely to the traveling direction -of the web 13, and is equal in width to top plate 1 between ;
end plates 13 and 13a. In tha preferred embodiment of the invention, the distance of the spoiler 7 from curved edge lb ;' ~ " ~ ~: , .
. . .
~ ~L~ ' Z~
is between 40 to 100 mm. The spoiler 7 can be shifted in the direction of the web travel in order to harmonize the zone of over pre~sure and that of under pressure, as still shall be explained. For this purpose closeable slots 8 can be provided in the top plate 1 in which the spoiler 7 is fixed for instance by bolts and nuts 8a. In lieu of a mechanical spoiler 7, a jet spoiler may be used wherein a plurality of transversely arrayed apertures 8b may be formed in top plate 1.
As seen in the travel direction of the web another nozzle aperture 11 is provided behind the spoiler 7 which is formed by the reax straight edge la of the top plate 1 and the curved front edge of a diffuser sheet 5. The width of the rear nozzle il is between 2 mm and 16 mm. The distance of the highest point 5a of the diffuser sheet 5 from the material web 13 is less than the distance of the top plate 1 from the material web 13. Departing from point 5a the distance of the diffuser sheet 5 from web 13 increases, since the diffuser sheet extends at a small angle from the horizontal in the direction of the base 12.
For better control of lateral chargin~ of the plenum 10 with the gas, guide baffles 16 are provided heneath nozzle slots g and 11. For this purpose flanges 15 and 15a are pro-vided to project downwardly from top plate l adjacent the nozzle slots 9 and 11, respectively. Between these 1anges 15 and 15a and t~e lateral sur~aces 14 o~ the plenum 10 are ;
located the individual guide baffles 16 which are formed by ~mall plates curved toward end pLate 13 in their lower portions.
The guide baffles 16 are set up in series in the nozzle clearances 9, ll perpendicularly ~o the lateral sUrfaCeS 14 of the plenum 10.
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.
2'd In operation, from the nozzle orifice 9 a jet is -~
discharged which strikes the web of material 13 nearly tangentially. Due to the shape of the guide surface 3 the jet is detached from the curved edge lb and top plate 1 and adheres to the guide surface 3. The detachment of the jet from top plate 1 is assisted by the spoiler 7 which tends to confine the jet in the space 17 between the anterior ~ -nozzle slot 9 and the spoiler 7. The spoiler 7 obstructs the flowing of the jet from the space 17 by providing a ;~
10 constricted throat 15 between the spoiler 7 and the material ~
web 13 which is narrower than the cross section of the space ~ :
17 between the top plate and the material web 13. In the space 17 a gas cushion is therefore formed with higher pressure, .~`
which is similar in effect to an air cushion. This air cushion `.
15 is the more pronounced the smaller the distance of the material :~
web 13 is from the top.plate 1, so that as shown in area I of FIGURE 2, with a decreasiny distance of the material web 13 from the top plate 1 the lifting capacity is extraordinarily increased. -.
: 20 In ~onsequence of the constricted throat 15 caused by the spoiler 7, ~he flow of gas is accelerated through ~he throat -~-15. There is created a pressure drop and the gas emerging from ~`
the nozzle slot 11 is thereby accelerated. There is a lower pressure area between the material we~ 13 and the diffuser sheet 5 which is further reduced to nearly ambient pressure by the diffuser-like widening of the diffuser sheet 5 ~rom the material web 13. Thi~ diffuser area is substantially filled by the gas that flows therein.from the nozz.le.slot 11.
In FIGURE 2 the pressure distribution over the length of the plenum 10 is shown for several clearances between the -- ' _ 9 _ ..
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material web 13 and the top plate 1. The ranyes of high pressure and low pressure are separated from each other by a null point where the pressure curves at 20 mm and 30 mm clearance intersect. It is apparent from this curve that the pressure drops with an increase of the clearance of the material web 13 ~rom the top plate 1, until at about 50 mm clearance the pressure is substantially zero, or under certain circumstances slightly negative. Thus fox a large range of weights per unit area of material a state of equilibrium can be established between the material and the plenum by proper selection of jet force and material clearance ~rom the plenum wherein a satisfactory, flutter free guidance of the material can be maintained.
In application, a plurality of plenums are employed, the actual number depending on the distance required to convey the material. By locating the plenums beneath the material and spaced apart from center line to~center line between two and three times the cross-sectional width of a plenum the high pressure zone over each plenum and the low pressure zone be-tween each plenum, as shown in FIGURE 2, induces in the materiala sinusoidal or wave-like motion whereby the material is conveyed from plenum to plenum. This wave-like motion has been found to be quite advantageous in that it prevents canoeing ...
~ o~ the material as it is being conveyed. `It will be appreci-ated that this is so becausa each reversal of position of the material from trough to peak of the sinusoid inhibits any tendency of ~he material to canoe between troughs and peaXs.
This invention is suitable to convey many t~pes of materials including paper, plastics, textiles and ferrous and non-errous metals so long as the unit weight of the material . ~`"'~.
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.
" ~ : '' '' i7~
does not exceed the lifting force of the jet. In the pre-ferred embodiment described a nozzle pressure of 1" water column with material strip tension in the order of 1 kilogram per square mm has proved to be satisfactory. The nozzles in ~-the preferred embodiment are spàced apart approximately 500 mm, and spacing between plenum center lines from 1,000 to 1,500 mm -has yielded good results. -For certain materials a more positive control of the low pressure area may be desirable. In which case, the plenums may be placed vertically on opposite sides of the material in a staggered relationship whereby both positive and negative - -pressures will be produced directly by the plenum nozzles in lieu of developing a low pressure zone by virtue of decay of pressure outside of the high pressure zone such as charted ~ ~
15 in FIGURE 2. In this application high and low pressures are ~ ~ ;
only relative terms, both pressures being produced by positive ~`~
nozzle pressure. With staggered plenumi the top plates 1 will be adjacent the material and the bottom plates 12 will be remote from the material as shown in FIGURE 3, irrespective of whether a plenum is considered to be relatively above or below the material. In another application the material may - be conveyed in a vertical plane when the catenary effect on the material is not objectionable. In this application, of course, the plenums will be positioned horizontally on opposite sides of the material, instead of above and below the material, with the nozzle material relationship of FIGURE 3 remaining the same.
It is believed that the invention, its method and apparatus, and its advantages will be understood from the foregoing description, and it is further believed that, while , .
.. . . .
72~
preferred embodiments of the invention have been shown and described for illustrative purposes, the structural details are nevertheless capable of variatior. within the intent and scope of the invention as defined in the appended claims.
- '~;
: ' , .~
- .~ ::
.
discharged which strikes the web of material 13 nearly tangentially. Due to the shape of the guide surface 3 the jet is detached from the curved edge lb and top plate 1 and adheres to the guide surface 3. The detachment of the jet from top plate 1 is assisted by the spoiler 7 which tends to confine the jet in the space 17 between the anterior ~ -nozzle slot 9 and the spoiler 7. The spoiler 7 obstructs the flowing of the jet from the space 17 by providing a ;~
10 constricted throat 15 between the spoiler 7 and the material ~
web 13 which is narrower than the cross section of the space ~ :
17 between the top plate and the material web 13. In the space 17 a gas cushion is therefore formed with higher pressure, .~`
which is similar in effect to an air cushion. This air cushion `.
15 is the more pronounced the smaller the distance of the material :~
web 13 is from the top.plate 1, so that as shown in area I of FIGURE 2, with a decreasiny distance of the material web 13 from the top plate 1 the lifting capacity is extraordinarily increased. -.
: 20 In ~onsequence of the constricted throat 15 caused by the spoiler 7, ~he flow of gas is accelerated through ~he throat -~-15. There is created a pressure drop and the gas emerging from ~`
the nozzle slot 11 is thereby accelerated. There is a lower pressure area between the material we~ 13 and the diffuser sheet 5 which is further reduced to nearly ambient pressure by the diffuser-like widening of the diffuser sheet 5 ~rom the material web 13. Thi~ diffuser area is substantially filled by the gas that flows therein.from the nozz.le.slot 11.
In FIGURE 2 the pressure distribution over the length of the plenum 10 is shown for several clearances between the -- ' _ 9 _ ..
:~3'72~
material web 13 and the top plate 1. The ranyes of high pressure and low pressure are separated from each other by a null point where the pressure curves at 20 mm and 30 mm clearance intersect. It is apparent from this curve that the pressure drops with an increase of the clearance of the material web 13 ~rom the top plate 1, until at about 50 mm clearance the pressure is substantially zero, or under certain circumstances slightly negative. Thus fox a large range of weights per unit area of material a state of equilibrium can be established between the material and the plenum by proper selection of jet force and material clearance ~rom the plenum wherein a satisfactory, flutter free guidance of the material can be maintained.
In application, a plurality of plenums are employed, the actual number depending on the distance required to convey the material. By locating the plenums beneath the material and spaced apart from center line to~center line between two and three times the cross-sectional width of a plenum the high pressure zone over each plenum and the low pressure zone be-tween each plenum, as shown in FIGURE 2, induces in the materiala sinusoidal or wave-like motion whereby the material is conveyed from plenum to plenum. This wave-like motion has been found to be quite advantageous in that it prevents canoeing ...
~ o~ the material as it is being conveyed. `It will be appreci-ated that this is so becausa each reversal of position of the material from trough to peak of the sinusoid inhibits any tendency of ~he material to canoe between troughs and peaXs.
This invention is suitable to convey many t~pes of materials including paper, plastics, textiles and ferrous and non-errous metals so long as the unit weight of the material . ~`"'~.
.
.
" ~ : '' '' i7~
does not exceed the lifting force of the jet. In the pre-ferred embodiment described a nozzle pressure of 1" water column with material strip tension in the order of 1 kilogram per square mm has proved to be satisfactory. The nozzles in ~-the preferred embodiment are spàced apart approximately 500 mm, and spacing between plenum center lines from 1,000 to 1,500 mm -has yielded good results. -For certain materials a more positive control of the low pressure area may be desirable. In which case, the plenums may be placed vertically on opposite sides of the material in a staggered relationship whereby both positive and negative - -pressures will be produced directly by the plenum nozzles in lieu of developing a low pressure zone by virtue of decay of pressure outside of the high pressure zone such as charted ~ ~
15 in FIGURE 2. In this application high and low pressures are ~ ~ ;
only relative terms, both pressures being produced by positive ~`~
nozzle pressure. With staggered plenumi the top plates 1 will be adjacent the material and the bottom plates 12 will be remote from the material as shown in FIGURE 3, irrespective of whether a plenum is considered to be relatively above or below the material. In another application the material may - be conveyed in a vertical plane when the catenary effect on the material is not objectionable. In this application, of course, the plenums will be positioned horizontally on opposite sides of the material, instead of above and below the material, with the nozzle material relationship of FIGURE 3 remaining the same.
It is believed that the invention, its method and apparatus, and its advantages will be understood from the foregoing description, and it is further believed that, while , .
.. . . .
72~
preferred embodiments of the invention have been shown and described for illustrative purposes, the structural details are nevertheless capable of variatior. within the intent and scope of the invention as defined in the appended claims.
- '~;
: ' , .~
- .~ ::
.
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In apparatus for jet flotation conveyance of strip materials, the improvement in flotation means comprising: a plenum adapted to receive a pressurized gas therein; said plenum having a pair of spaced apart side members; a top flat member spaced intermediate said side members and spaced apart therefrom to define a pair of nozzles therebetween; one edge of said top member being curved downwardly; the top edge of the side member adjacent said top member curved edge extending upwardly and curved inwardly to project over said top member at an acute angle thereto to define an aperture parallel to and greater than the width of the adjacent nozzle; a spoiler exterior of said plenum between said nozzles; the top edge of the other of said side members being curved outwardly away from said top plate and then extending to form an acute angle with said other side portion; and a pair of plates secured to the underside of said top member and projecting downwardly therefrom and parallel to said nozzles; the bottom edges of said plates being curved inwardly.
2. The apparatus of claim 1, including a plurality of curved baffle plates spaced apart and normally secured between said side members and said downwardly projecting plates.
3. The apparatus of claim 1, including means to shift said spoiler longitudinally between said nozzles.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2556442A DE2556442C2 (en) | 1975-12-15 | 1975-12-15 | Device for the floating guidance of material webs |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1043728A true CA1043728A (en) | 1978-12-05 |
Family
ID=5964442
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA267,851A Expired CA1043728A (en) | 1975-12-15 | 1976-12-14 | Method and apparatus for floatation conveyance of strip materials |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US4074841A (en) |
| CA (1) | CA1043728A (en) |
| DE (1) | DE2556442C2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8061055B2 (en) | 2007-05-07 | 2011-11-22 | Megtec Systems, Inc. | Step air foil web stabilizer |
Families Citing this family (52)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2802610C2 (en) * | 1978-01-21 | 1983-05-05 | Vits-Maschinenbau Gmbh, 4018 Langenfeld | Blow box for floating guidance and / or conveying of webs or sheets |
| DE2836103C2 (en) * | 1978-08-17 | 1985-03-21 | Jagenberg-Werke AG, 4000 Düsseldorf | Air nozzle for a nozzle dryer |
| US4201323A (en) * | 1978-10-12 | 1980-05-06 | W. R. Grace & Co. | High velocity web floating air bar having a recessed Coanda plate |
| US4197973A (en) * | 1978-10-12 | 1980-04-15 | W. R. Grace & Co. | High velocity web floating air bar having air flow straightening means for air discharge slot means |
| SE429770B (en) * | 1978-12-06 | 1983-09-26 | Flaekt Ab | DEVICE FOR DRYING OF COATED MATERIAL |
| DE3026132A1 (en) * | 1980-07-10 | 1982-02-11 | Carl Prof. Dr.-Ing. 5100 Aachen Kramer | NOZZLE SYSTEM |
| US4329315A (en) * | 1980-10-24 | 1982-05-11 | Monsanto Company | Sheet stress relaxation |
| US4738407A (en) * | 1980-11-20 | 1988-04-19 | Monsanto Company | Manipulating large sections of artificial turf |
| US4399954A (en) * | 1980-11-20 | 1983-08-23 | Monsanto Company | Manipulating large sections of artificial turf |
| US4414757A (en) * | 1981-10-07 | 1983-11-15 | Overly, Incorporated | Web dryer nozzle assembly |
| US4606137A (en) * | 1985-03-28 | 1986-08-19 | Thermo Electron Web Systems, Inc. | Web dryer with control of air infiltration |
| US4601116A (en) * | 1985-05-16 | 1986-07-22 | Worldwide Converting Machinery, Inc. | Coanda nozzle dryer |
| US4718178A (en) * | 1985-11-29 | 1988-01-12 | Whipple Rodger E | Gas nozzle assembly |
| JPS62167162A (en) * | 1986-01-21 | 1987-07-23 | Fuji Photo Film Co Ltd | Floating type web transportation device |
| SE458860B (en) * | 1986-02-06 | 1989-05-16 | Itronic Process Ab | DEVICE FOR A HEAT TREATMENT OF TREATED ARTICLES ORGANIZED TREATMENT ESTABLISHMENT |
| DE3604819A1 (en) * | 1986-02-15 | 1987-08-20 | Bayer Ag | PROMOTION OF FILAMENT COVERING THROUGH WIDE CONVEYOR |
| US4698914A (en) * | 1986-05-29 | 1987-10-13 | E. I. Du Pont De Nemours And Company | Setting/drying process for flexible web coating |
| US4785986A (en) * | 1987-06-11 | 1988-11-22 | Advance Systems, Inc. | Paper web handling apparatus having improved air bar with dimensional optimization |
| ATE68221T1 (en) * | 1987-07-07 | 1991-10-15 | Hilmar Vits | DEVICE FOR CONTACTLESS GUIDE OF MATERIAL WEBS. |
| DE3822624A1 (en) * | 1987-07-07 | 1989-02-09 | Hilmar Vits | Apparatus for the contactless guidance of material webs |
| FI78525C (en) * | 1987-11-02 | 1989-08-10 | Valmet Paper Machinery Inc | infra-drying |
| JP2782516B2 (en) * | 1988-09-19 | 1998-08-06 | 富士写真フイルム株式会社 | Non-contact web transfer device |
| GB8823815D0 (en) * | 1988-10-11 | 1988-11-16 | Molins Plc | Pneumatic web feeding |
| US5184555A (en) * | 1989-04-19 | 1993-02-09 | Quad/Tech, Inc. | Apparatus for reducing chill roll condensation |
| US5347726A (en) * | 1989-04-19 | 1994-09-20 | Quad/Tech Inc. | Method for reducing chill roll condensation |
| FI96125C (en) * | 1991-09-05 | 1996-05-10 | Valmet Paper Machinery Inc | Arrangement of suppressor nozzles intended for treatment of webs and method of an arrangement for suppressor nozzles intended for treatment of webs |
| US5370289A (en) * | 1992-02-21 | 1994-12-06 | Advance Systems, Inc. | Airfoil floater apparatus for a running web |
| DE4229804A1 (en) * | 1992-09-07 | 1994-03-10 | Erich Dipl Ing Hansmann | Device for generating an air flow system for the treatment of continuous sheet material |
| DE4240700C2 (en) * | 1992-12-03 | 2003-11-06 | Carl Kramer | Device for floating guidance of a moving material web |
| DE4301023C3 (en) * | 1993-01-16 | 2001-07-26 | V I B Systems Gmbh | Device for increasing the gloss and / or smoothness of a paper web |
| DE19619547A1 (en) * | 1996-05-15 | 1997-11-27 | Vits Maschinenbau Gmbh | Air cushion nozzle and device for heat treatment of a continuously moving web with air cushion nozzles |
| CA2190563C (en) * | 1996-11-18 | 1999-10-26 | Ralph Mancini | Device and method to stabilize sheet between press section and dryer section of a paper-making machine |
| US5851357A (en) * | 1997-03-03 | 1998-12-22 | Valmet, Inc. | Combination saveall and blowbox system |
| FI108870B (en) * | 1997-05-30 | 2002-04-15 | Metso Paper Inc | Fan Drying Unit |
| US6260287B1 (en) * | 1997-08-08 | 2001-07-17 | Peter Walker | Wet web stability method and apparatus |
| EP0965546A1 (en) * | 1998-06-17 | 1999-12-22 | E.I. Du Pont De Nemours And Company | Web transport system |
| DE10007004B4 (en) * | 2000-02-16 | 2006-04-06 | Lindauer Dornier Gmbh | Method for guiding a material web and heat treatment device |
| US6514072B1 (en) * | 2001-05-23 | 2003-02-04 | Harper International Corp. | Method of processing carbon fibers |
| US6564473B2 (en) * | 2001-10-22 | 2003-05-20 | The Procter & Gamble Company | High efficiency heat transfer using asymmetric impinging jet |
| US6936137B2 (en) * | 2001-10-24 | 2005-08-30 | Honeywell International Inc. | Air clamp stabilizer for continuous web materials |
| US7530179B2 (en) * | 2004-04-13 | 2009-05-12 | Megtec Systems, Inc. | Step air foil |
| DE102004039652A1 (en) * | 2004-08-11 | 2006-02-23 | Octagon Process Technology Gmbh | Thickness profile measuring device for thin-layered measuring objects |
| US7311234B2 (en) * | 2005-06-06 | 2007-12-25 | The Procter & Gamble Company | Vectored air web handling apparatus |
| US7694433B2 (en) * | 2005-06-08 | 2010-04-13 | The Procter & Gamble Company | Web handling apparatus and process for providing steam to a web material |
| ITFI20060205A1 (en) * | 2006-08-11 | 2008-02-12 | Perini Fabio Spa | DEVICE AND METHOD FOR FEEDING SAILS OF TWO-TONE MATERIAL |
| US8568125B2 (en) | 2008-04-14 | 2013-10-29 | Microgreen Polymers Inc. | Roll fed flotation/impingement air ovens and related thermoforming systems for corrugation-free heating and expanding of gas impregnated thermoplastic webs |
| US8083895B2 (en) * | 2008-04-18 | 2011-12-27 | Honeywell Asca Inc. | Sheet stabilization with dual opposing cross direction air clamps |
| US8088255B2 (en) * | 2008-04-18 | 2012-01-03 | Honeywell Asca Inc | Sheet stabilizer with dual inline machine direction air clamps and backsteps |
| US8083896B2 (en) * | 2008-09-26 | 2011-12-27 | Honeywell Asca Inc. | Pressure equalizing baffle and coanda air clamp |
| CA2976789C (en) | 2009-06-05 | 2019-12-31 | Megtec Systems, Inc. | Method of drying a web of printed material |
| JP6434160B2 (en) * | 2015-02-12 | 2018-12-05 | ボブスト メックス ソシエテ アノニム | Web support and stabilization unit for a print head and printing station equipped therewith |
| FI127350B (en) * | 2015-09-07 | 2018-04-13 | Raute Oyj | Nozzle box and dryer |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE975243C (en) * | 1951-04-03 | 1961-10-12 | Artos Maschb Dr Ing Meier Wind | Device for non-contact guiding of webs to be dried |
| DE1474239C3 (en) * | 1964-09-03 | 1979-10-25 | Vits-Maschinenbau Gmbh, 4018 Langenfeld | Method and device for stabilizing the position of floating webs of material under the action of a blowing agent |
| DE1774126B1 (en) * | 1968-04-13 | 1972-07-13 | Vits Maschb Gmbh | Device for stabilizing the position of sheet or arch-shaped workpieces |
| US3559301A (en) * | 1968-07-29 | 1971-02-02 | Egan Machinery Co | Air flotation system for conveying web materials |
| US3587177A (en) * | 1969-04-21 | 1971-06-28 | Overly Inc | Airfoil nozzle |
| US3763571A (en) * | 1970-04-27 | 1973-10-09 | Vits Maschinenbau Gmbh | Apparatus for contactless guiding of webs |
-
1975
- 1975-12-15 DE DE2556442A patent/DE2556442C2/en not_active Expired
-
1976
- 1976-12-09 US US05/749,109 patent/US4074841A/en not_active Expired - Lifetime
- 1976-12-14 CA CA267,851A patent/CA1043728A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8061055B2 (en) | 2007-05-07 | 2011-11-22 | Megtec Systems, Inc. | Step air foil web stabilizer |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2556442A1 (en) | 1977-06-23 |
| US4074841A (en) | 1978-02-21 |
| DE2556442C2 (en) | 1984-09-06 |
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