Publish Time: 2025-11-28 Origin: Site
The production efficiency and energy consumption of the paper machine press section are closely related, and the energy consumption of the vacuum system accounts for a considerable proportion of the total energy consumption of the press section. Therefore, setting up a reasonable vacuum system in the press section and optimizing the configuration of the vacuum system are important ways to provide efficient and energy-saving solutions for paper machines.
1) Vacuum Suction Roller and Vacuum Suction Box
The main function of vacuum suction rollers and vacuum suction boxes is to help the paper web smoothly transfer from the mesh to the press section. Currently, suction rollers (boxes) are mostly used in the form of contacting the paper web through the press felt. The suction volume should not be too high, and the vacuum degree should be maintained at 30-50kPa.
2) Vacuum Suction Box
There are vacuum suction boxes, vacuum dehydration tanks, and vacuum washing boxes used in the press section. Due to their different functions, there are inevitable differences in their technical parameters and requirements.
The structural design of the press felt should meet the requirements of the paper machine. After leaving the felt suction vacuum box, the moisture content in the felt is generally about one-third of its own weight. Excessive vacuum configuration does not help reduce the moisture in the felt, but instead exacerbates its wear and tear. The minimum width of the felt suction box slot should be controlled at around 12mm to prevent fiber bridging, blockage, and suction. The maximum width should not exceed 20mm to prevent the felt from being sucked into the seam and exacerbating its wear. The vacuum suction box is generally used on the back of the paper making felt before the pressing zone. Its function is not only to absorb the moisture transferred from the wet paper sheet in the felt, but also to evenly adsorb the wet paper sheet onto the surface of the felt, preventing it from entering the pressing zone and causing bubbling and wrinkling. The vacuum degree of the felt suction box is generally between 30~40kPa.
3) Felt Suction Box
The felt suction box is a specialized vacuum box used for washing and controlling the moisture content of felt during their return journey. The felt washing vacuum box is divided into two types: low-pressure vacuum box and high-pressure vacuum box. When the speed of the papermaking locomotive is low, a single box double slot suction box is generally sufficient. When the machine speed is greater than 600 and producing higher grade paper, in order to strengthen the cleaning of the felt, both a low-pressure vacuum box and a high-pressure vacuum box can be used simultaneously. The low-pressure vacuum box has a double slot opening with an opening width of 12-18mm and a vacuum degree of 20-30 kPa; The high-pressure vacuum box has a single slit opening with a width of 10-16mm and a vacuum degree of 20-40kPa.
4) Vacuum Suction Press Roll
Vacuum press and vacuum composite press are one of the main press types of paper machines, which are widely used in paper machines due to their higher dewatering efficiency than ordinary flat roll press and groove press. Generally, the vacuum suction rolls used for upper and lower roller vacuum pressing have a vacuum chamber width ranging from approximately 10 to 15cm; The vacuum composite press roller generally has two vacuum chambers, one is a low-pressure vacuum chamber and the other is a high-pressure vacuum chamber. The vacuum degree of the low-pressure vacuum chamber is generally between 30-40 kPa, and the vacuum degree of the high-pressure vacuum chamber is generally between 40-60 kPa. The size of the vacuum degree is determined by the pressing and dewatering state of the paper machine. If the vacuum degree is too high, it is easy to have vacuum marks on the paper surface, as well as problems such as excessive hair removal and wear on the press felt, and energy waste; If the vacuum degree is too low, the dehydration characteristics of vacuum pressing cannot be fully utilized.