GB964123A - Improvements in means for conditioning paper in web form - Google Patents

Abstract

964,123. Web treating apparatus. GREENBANK ENGINEERING CO. Ltd., and EASTON & JOHNSON Ltd. April 18, 1963 [April 27, 1962], No. 16107/62. Heading D1L. A machine for the addition of predetermined controlled amounts of moisture to a paper web, comprises two drums around which the web is passed, arranged with their axes one above the other, a pressure box arranged below the peripheral surface of the lower drum, a second pressure box arranged above the peripheral surface of the upper drum, each box having a surface concentric with a portion of the surface of the drum through which humidified air can be blown on to the web as it passes round the drum, a chamber in which the drums are located, means for supplying air under pressure to the pressure boxes, a humidifying device through which the air passes during its travel to the boxes, an outlet duct from the chamber adapted to be connected to atmosphere or to the air inlet side of the means supplying air under pressure to the boxes, a fresh air inlet on the inlet side of aforesaid means, and means for controlling the direction of travel of the air after passing out of the chamber. The machine shown comprises an insulated chamber A having an inlet a and an outlet a<SP>1</SP> for a web w of paper coming direct from the calender of a paper making machine. Two drums B<SP>1</SP> and B<SP>2</SP> adapted to be rotated at the same peripheral speed as the speed of the web are mounted in the chamber A and the web is guided around the drums as shown. Humidified air is supplied to the surface of the web as it passes round the drums B<SP>1</SP>, B<SP>2</SP> by pressure boxes C<SP>1</SP>C<SP>2</SP> supplied by suitable ducts D<SP>1</SP>, D<SP>2</SP> from a common pump D and humidifying d which may be provided with a heater d<SP>3</SP>. Dampers d<SP>1</SP> and d<SP>2</SP> are provided for regulating the supply. The peripheral surfaces of drums B<SP>1</SP>, B<SP>2</SP> may be perforated and ducts E<SP>1</SP>, E<SP>2</SP> connected to the interiors of the drums. Dampers e<SP>1</SP>, e<SP>2</SP> allow recirculation of the air from ducts E<SP>1</SP>, E<SP>2</SP> discharge to atmosphere. Humidified air in chamber A passes out via duct D<SP>3</SP> which is open to atmosphere and to duct D<SP>4</SP> leading to the inlet side of pump D. Fresh air may be let into the system through direct d<SP>4</SP> by damper d<SP>5</SP>. The drums B<SP>1</SP>, B<SP>2</SP> are preferably formed with an outwardly spirally wire-wound surface to produce a lateral spreading effect on the web.