The present invention provides a closed and pressure-controlled extraction process for nylon 6 chips. During extraction, the overall pressure in the extraction tower is increased by isolating the atmosphere and controlling the pressure. In order to solve a series of drawbacks, such as low extraction efficiency, slow extraction speed, difficult manipulation, etc., which have seriously affected the yield and quality of the slices, the present invention improves the process water temperature by pressurizing and reduces the vapor volatilization without affecting the extraction water and the orderly movement state of the slices in the original extraction column. At the same time, the process of the invention reduces the operation cost of the equipment, reduces the amount of materials such as heating steam, desalted water, cooling water and electricity, and greatly reduces the production cost of the nylon 6 chip. The maneuverability of the process is improved, and the difficulty of process control is reduced.
【技术实现步骤摘要】
一种密闭且加压可控的锦纶6切片的萃取工艺
本专利技术涉及一种锦纶6切片的萃取工艺,尤其涉及一种密闭且加压可控的锦纶6切片的萃取工艺。
技术介绍
在锦纶6切片的生产中,聚合物达到平衡时,己内酰胺的转化率一般在90%左右,这意味着聚合物中还残余10%左右的己内酰胺与低聚物(低聚物指的是在聚合过程中所产生的低分子聚合物。一般来说,定义低聚物的范围是指从一聚体到十聚体的低分子聚合物,包括线状低聚物和环状低聚物)。大量的己内酰胺和低聚物如果随切片进入纺丝工段,不仅会对纺丝工艺造成严重的后果,同时也是对原料的极大浪费。锦纶6切片生产过程中,萃取工序是一个对切片质量有着重大影响的关键工序。萃取是为了除去切片中大部分低分子物,使低分子物含量低于0.5%,以符合高速纺丝要求。由于单体和低聚物可溶解于热水,可利用热水作为萃取剂。在热水与切片的接触过程中,水分子不断的渗透到切片内部,低分子物不断从切片中扩散出来溶解于热水中,使切片中低分子物不断减少。为了最大限度地萃取完切片中的单体和低聚物,所以采用逆流分段连续萃取。上段用含一定浓度单体和低聚物的循环萃取水溶液,以萃取低聚物为主,下段用热水以萃取单体为主,并及时移走上段部分萃取水溶液去回收,上段减少的萃取水由下段热水补充。提高萃取温度是提高萃取效果的重要手段。现有大多数锦纶6切片的萃取是常压联通大气的,当塔内萃取水在相应温度下的饱和蒸汽压大于所在位置处的压力时就会发生气化沸腾。气泡翻腾会严重影响萃取塔内萃取水的有序流动进而影响了切片从高位槽向下移动,使得萃取塔难以操控。所以萃取水水温的限制严重制约了萃取的效果。为了防止水气化翻腾 ...
【技术保护点】
1.一种密闭且加压可控的锦纶6切片的萃取工艺,其特征在于:萃取时,通过隔绝大气且加压控制的方式提高萃取塔内整体的压力。
【技术特征摘要】
1.一种密闭且加压可控的锦纶6切片的萃取工艺,其特征在于:萃取时,通过隔绝大气且加压控制的方式提高萃取塔内整体的压力。2.根据权利要求1所述的密闭且加压可控的锦纶6切片的萃取工艺,其特征在于:所述加压控制是将萃取塔顶端的压力控制在0.15Mpa。3.根据权利要求1所述的密闭且加压可控的锦纶6切片的萃取工艺,其特征在于:在所述萃取塔的顶部加装压力表和气压调节器,从而实现加压控制。4.根据权利要求3所述的密闭且加压可控的锦纶6切片的萃取工艺,其特征在于:所述气压调节器包括气体增压阀和放空阀,所述气体增压阀通过增压...
【专利技术属性】
技术研发人员:张悦,
申请(专利权)人:长乐力恒锦纶科技有限公司,
类型:发明
国别省市:福建,35
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