Method and device for guiding a paper web or the like

Abstract

The invention relates to a method and device for guiding a paper web, or corresponding web-like moving track, by using jets of compressed air as an aid. There are two jet directions, one essentially facing the arrival direction of the web ( 1 ) and the other essentially facing the departure direction of the web ( 1 ), in which case the jets form an area of vacuum between them. Compressed air is fed from one or more inlet ducts ( 3, 6 ).

1 . Method for guiding a paper web, or corresponding web-like moving track, by using jets of compressed air as an aid, characterized in that the web is guided with the aid of a vacuum created on the surface ( 2 ), or in the immediate vicinity of the area between two air-jet discharge openings that are oriented essentially in the arrival direction of the web and in the departure direction of the web. 
   
   
       2 . Method according to  claim 1 , characterized in that the surface between the discharge ducts ( 4 ,  5 ) of the air jets is made to be essentially flat and impermeable by air. 
   
   
       3 . Method according to  claim 1 , characterized in that a single inlet duct ( 3 ) and two air-jet ducts ( 4 ,  5 ) leading out of it in two directions are used to feed the compressed air. 
   
   
       4 . Method according to  claim 1 , characterized in that two separate inlet ducts ( 3 ,  6 ), which feed air in two different directions, are used to feed the compressed air. 
   
   
       5 . Method according to any of the above claims, characterized in that the air-jet ducts ( 4 ,  6 ) are located over essentially the entire width of the web being guided. 
   
   
       6 . Method according to any of the above claims, characterized in that the air is fed through air-jet nozzles located in shoulders ( 11 ,  12 ). 
   
   
       7 . Device for guiding a paper web, or corresponding web-like moving track, by using jets of compressed air as an aid, characterized in that in the device there are compressed-air jet nozzles ( 4 ,  5 ) on either side of a surface that is essentially impermeable by air, of which the nozzles on one side are oriented essentially in the arrival direction of the web ( 1 ) and the nozzles on the other side are oriented essentially in the departure direction of the web ( 1 ), which jets form an area of vacuum between them. 
   
   
       8 . Device according to  claim 7 , characterized in that the air-jet nozzles ( 4 ,  5 ) are located on the two sides of an essentially smooth surface ( 2 ), the nozzle surfaces of the jets being essentially on or below the plane of the surface. 
   
   
       9 . Device according to  claim 7 , characterized in that there is only one inlet duct ( 3 ) for feeding the compressed air to the jet nozzles. 
   
   
       10 . Device according to  claim 7 , characterized in that there are two inlet ducts ( 3 ,  6 ) for feeding the compressed air to the jet nozzles. 
   
   
       11 . Device according to  claim 7 , characterized in that the air-jet nozzles are formed of rows of jet holes located on the surface ( 2 ) and essentially transversely to the direction of travel of the web being guided. 
   
   
       12 . Device according to  claim 7 , characterized in that the air jets feed by the jet nozzles form mutually approximately a straight angle. 
   
   
       13 . Device according to  claim 7 , characterized in that the discharge openings of the airjet are located in shoulders ( 11 ,  12 ).