Method and apparatus for drying paper on a yankee dryer

Abstract

Abstract PAPERMAKING APPARATUS IS DISCLOSED WHICH INCLUDES STEAM SUPPLY MEANS ADAPTED TO APPLY STEAM TO THE SURFACE OF A WET PAPER WEB TO BE DRIED IN THE REGION IMMEDIATELY PRECEDING THE POINT WHERE THE PAPER WEB CONTACTS THE SURFACE OF THE YANKEE DRYER. ONE EMBODIMENT OF THE METHOD AND APPARATUS DISCLOSED INVOLVES CONTACTING A WET PAPER WEB WITH STEAM IMMEDIATELY BEFORE IT PASSES INTO THE ON-RUNNING SIDE OF A DRYING NIP FORMED BY A PRESSURE ROLL IN CONTACT WITH THE YANKEE DRYER. EMBODIMENTS OF THE METHOD AND APLPARATUS ARE DISCLOSED IN WHICH THE ABOVE FEATURE IS UTILIZED IN CONJUNCTION WITH SUCTION PRESSURE ROLLS, AND SOLID ROLLS, SUCH AS BLIND DRILLED ROLLS AND GROOVED ROLLS. A FURTHER EMBODIMENT IS DISCLOSED IN WHICH STEAM IS ALSO APPLIED TO THE EXPOSED SURFACE OF A WET PAPER WEB CARRIED ON A YANKEE DRYER BETWEEN TWO SUCCESSIVE PRESSURE ROLLS. ONE DISCLOSED FORM OF THIS EMBODIMENT INVILVES THE USE OF A HOOD BETWEEN THE PAPER WEB AND THE FELT LOOP RUNNING FROM ONE PRESSSURE ROLL, AROUND A GUIDE ROLL AND TO A SUCCESSIVE PRESSURE ROLL. ANOTHER DISCLOSED FORM OF THIS EMBODIMENT INVOLVES ENCLOSING THE ENDS OF THE SPACE DEFINED BY THE FELT LOOP AND THE SURFACE OF THE YANKEE DRYER AND THE INSERTION OF STEAM INTO THAT SPACE TO ELEVATE THE VAPOR PRESSURE INSIDE THE SPACE AT LEAST TO THE VAPOR PRESSURE OF THE WET PAPER WEB CARRIED ON THE YANKEE DRYER AND, PREFERABLY, SUBSTANTIALLY TO ATMOSPHERIC PRESSURE.

Inventors

• 👤 Dean C Douglas
• 👤 Richard L Elderkin
• 👤 Donald F Pohlman

Bibliographic Details