Applied Research On The Paper Machine’s Vacuum System Of Kraft Paperboard

The vacuum part of paper machine is a complicated system, many factors should be considered. By scientific calculation and reasonable layout, it can achieve ideal effect. The wet vacuum system of papermaking not only affects the paper forming quality, but also relates the dryness of paper entering dryer. Thus it decides the steam consumption of paper manufacture. In the past, the production scale of paper machine is small, the structure is simple, and the vacuum configuration is simple, the vacuum system design did not pay attention in domestic. At present, the scale production and quality of paper is improving in domestic. But the problems that are wet part’s dewatering is uneven, power consumption is large and vacuum distribution is unreasonable are caused by vacuum system are prominent increasingly. In foreign papermaking engineering calculation is more rigorous than in domestic, but the technical is secret. Hence we cannot get some technical information and computing formula of the vacuum configuration.The composition of paper machine vacuum system and the principle of it’s different parts are introduced in this paper. Combined with the author’s years’ experience in work, referencing the related empirical data of 400, 000 tons and 450,000 tons board paper projects’ vacuum system, it is concluded that the layout of the vacuum components. By simulating the stock consistency and dehydrating amount of each vacuum working point, and combining the relevant empirical data, the vacuum pressure and flow rate of each vacuum operating point can be obtained. According to the vacuum pressure levels and experience, group the vacuum points. After grouping, select appropriate pump by calculating the air flow on the basis of Boyle Law. High efficiency and low comprehensive cost vacuum pump, reasonable vacuum pump arrangement, suitable vacuum pipeline arrangement, meeting the technology requests’ group and modern paper making automation control system are the basic requirements of efficient vacuum system configuration. The research results are applied in the project of Zhejiang Yongtai Paper Group Co., Ltd’s paper machine’s vacuum system of 500,000 tons high-grade wrapping paper(kraft paperboard and corrugated paper). The theoretical basis of paper machine vacuum system and the technical route are analyzed and researched deeply in this paper. It can get the goal of design and optimization the vacuum system. It also can improve the speed of paper machine, production capacity, the utilization rate of equipment, the quality of the final paper, and save energy and reduce consuming, and reduce the production cost of per ton paper. It can achieve the objective of the enterprise market competitiveness eventually.