青州造纸厂纸袋纸纸机干燥部蒸汽冷凝水系统技术改造的探讨

Study on Technical Modification of Steam & Condensate System to Drying Section of Sack Kraft Machine in Qingzhou Paper Mill

青州造纸厂五十年代引进VOITH公司150t/d纸袋纸纸机干燥部蒸汽系统,经过两次重大技术改造,成功地引用先进节能装置——热压泵,充分使汽水分离器的二次蒸汽升再利用,以强化烘缸的蒸发能力,文章详细介绍了诙系统技术改造的工艺条件对比、控制原理,节能效果计算和相应的配套设施,对目前国内大型纸机的干燥部蒸汽系统向节能型技术改造,提出了探讨意见。

The paper machine imported from Voith Co. in the fifties, with the daily production of 150 admt, maximum speed of 450 m/min, was originally designed with a constant heating system in its drying section, including an ASKANIA steam control unit. As the system was found unbalanced and too much condensate was accumulated in the dryers at 360-380m/ min, and thus it was difficult to raise the speed of machine. The drying system was rebuilt according to the common three section steam system in 1974. After the rebuilding the speed reached 415m/ min, but the steam consumption was up to 3.6t/1 paper since the inlet dryness of wet web was no more than 30.5%.The paper machine was modified in 1984. Some main equipments such as approach flow section, wire section, press section and seperate drives as well as finishing section were introduced from Beloit Italia.With such a modification, the speed can reach as high as 650m / min, its capacity was increased from 180t / d to 250t / d. The introduction of the advanced energy saving unit -thermocompressor into steam system makes it possible to reuse and increase the pressure of secondary steam from steam-condensate seperator, thus to enhance the evaporation capacity of dryers. The steam system includes no Run, intermidiate, main and after Clupak section. The new type Beloit steam joint and rotary syphon are used in dryers. It's proved that the load on'seperate drives of drying section has been significantly decreased, the steam consumption has been reduced to 2.4t /t. A succeccful energy-saving has been achieved.Mill has developed a new kind of sack kraft - extensible kraft since the installation of Clupak unit. A Measurex-2002 Basic Weight/ Moisture Sensor has been adopted. The bag-typed ventilator and closed steam housing has been installed to improve its ventilation. Mill also introduced the synthetic canvas with good porosity. The guide roll of canvas is lubricated concentratedly by the weak oil to ensure the safety and reliability of drive parts.