Vacuum Suction Box For Paper Machine On-line Case

# TYPE: Coating Board Paper Making TIME: 2017-07-19

    The pulp consistency is between 2~3%.  Dehydration capacity of chopping board and vacuum chopping board decreased significantly. Dehydration here must be done with a vacuum suction tank with a vacuum range of 10~33KPa. 

    When the net passes through the vacuum suction tank, at the beginning it removes moisture from the sheet only, but then the air passes through the net, and the air and water are pumped into the vacuum tank. Where there is a lot of moisture, the reflection of the light is strong, such as the mirror surface. The air penetrates the slurry layer, which is called "water line", sometimes called the "main line"". In general, the thickness of the water line is about 7%. In the new high-speed network (network stack, network folder etc.) of paper machine, line forward, can not see the water in the box.

    The suction tank dewatering is based on the suction action of the vacuum pump, producing high pressure difference between the upper and the lower parts of the paper, and dewatering the wet paper.，It is hoped that the wire section can be delivered to the press section with a higher dryness sheet, not blindly increase the degree of vacuum forced dehydration, which speeds up the wire section increase of wear, drive net power, improve the wire tension, have adverse effects on the life.

Number of Vacuum Box

    The number of the vacuum box is generally 7~9, according to the paper type, paper machine type, paper making speed is different.  in the network folder or stack of paper machine, the wet paper dry degree is greatly improved, the number of suction box is greatly reduced, usually using 2~5, without even. In order to adapt to the change of dryness of wet paper, vacuum degree of suction tank should be increased step by step.

    In the suction vacuum pump, water tank water air mixture from the suction tank out into the standpipe and water absorbing tank connected to the water under the action of gravity and air separation, white water drops to the water seal tank, air duct by converge to the vacuum pump suction.