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仪化公司涤纶一厂纺丝装置的中压蒸汽加热系统,其疏水器采用日本热静力型双金属片疏水器.投运后,出现中压蒸汽未能在金属加热辊筒中较好地放出热量就窜入冷凝水系统中的现象,导致加热不足,同时冷凝水集中系统无法正常回收二次蒸汽,造成能源浪费.一、改造前存在的问题1.加热辊筒换热不均匀每套纺丝装置的第三牵伸机有12个金属加热辊筒.加热时,用2.2MPa中压蒸汽在2.2s时间内将含一定水分的高速丝束温度升至100℃.为加快蒸汽放热,必须迅速排除饱和凝结水,但日本热静力型双金属片疏水器只能排出过冷度达20～30℃的过冷凝结水,因此,造成凝结水排除不及时,辊筒升温慢,上下辊筒温差大.为达到工艺要求,不得不开启疏水器旁通阀帮助疏水.但由于12个金属辊各配一套疏水器,八套纺丝装置又采取并联回水形式,一旦开启一个疏水旁通阀,未及放热的中压蒸汽直接窜入回水系统,造成回水背压升高,又减少其它加热辊凝结水排量,只得增开其它辊疏水旁通阀,继而影响到其它生产装置的加热,形成恶性循环.
The medium-pressure steam heating system of the spinning facility of the Polyester 1 Plant of Yihua Chemical Co., Ltd. uses a Japanese thermostatic type bimetallic sheet steam trap as its steam trap. After commissioning, the medium-pressure steam cannot be discharged well in the metal heating roll. The phenomenon of heat intrusion into the condensate system leads to insufficient heating. At the same time, the condensate water concentrating system cannot recover the secondary steam normally, resulting in energy waste. First, the problems existing before the transformation 1. Heat roller uneven heat transfer Each spinning The third drafting machine of the wire device has 12 metal heating rollers. During heating, 2.2MPa medium pressure steam is used to raise the temperature of the high-speed tow with certain moisture to 100°C in 2.2s. To speed up the steam heat release, Saturated condensate water must be quickly eliminated, but Japanese thermostatic type bimetal traps can only discharge super-condensed water that has a degree of supercooling of 20 to 30°C. As a result, condensate is not discharged in a timely manner, and the temperature of the roller is slowly increased. The temperature difference between the rollers is large. In order to meet the process requirements, the steam trap by-pass valve has to be opened to assist in the drainage. However, since 12 metal rollers each have a steam trap, the eight spinning devices adopt the parallel water return mode once they are opened. Bypass valve, not exothermic medium pressure steam Directly fleeing backwater system, resulting in the return back pressure, but also reduce other emissions condensate heating roller, other rollers had to open the bypass valve hydrophobic, thereby affecting the production of other heating means, a vicious circle.