Method of degassing of aqueous PVC dispersions
    1.
    发明授权
    Method of degassing of aqueous PVC dispersions 失效
    PVC水分散体脱气方法

    公开(公告)号:US4367331A

    公开(公告)日:1983-01-04

    申请号:US001527

    申请日:1979-01-08

    IPC分类号: C08F6/16 C08F14/06

    CPC分类号: C08F14/06 C08F6/16

    摘要: In the process for reducing the residual vinyl chloride monomer in an aqueous polyvinylchloride dispersion comprising the steps of depressurizing an aqueous polyvinylchloride dispersion containing emulsifiers and/or protective colloids as obtained from pressure polymerization in a polymerization zone, subjecting the same to a vacuum with heating, passing the gasses and foam of liquid constituents resulting from said depressurizing step and said vacuum treating step to a confined space wherein said gasses are separated from liquid constituents, and recovering an aqueous polyvinylchloride dispersion having a reduced residual vinyl chloride monomer content, the improvement consisting in passing said gasses and foam of liquid constituents to a confined space having a volume of not more than 331/3% of the volume of said polyvinylchloride dispersion and returning said foam of liquid constituents to said polyvinylchloride dispersion in said polymerization zone through an elongated zone of small cross-section below said confined space and at such a rate that said confined space is never completely filled with said foam of liquid constituents. According to the invention, the amount of liquid or foam accumulating in the confined space is pumped back into the degassing (polymerization) autoclave by means of a pump arranged underneath the confined space. The advantages consist in a better utilization of the separating capacity, a better and more uniform degassing of the product, and shorter degassing cycles.

    摘要翻译: 在聚氯乙烯水分散体中还原残留氯乙烯单体的方法中,包括如下步骤:在聚合区中从压力聚合得到的含有乳化剂和/或保护胶体的聚氯乙烯分散体水分减压,同时加热进行真空, 将由所述减压步骤和所述真空处理步骤产生的液体成分的气体和泡沫通入密闭空间,其中所述气体与液体组分分离,并回收具有减少的残余氯乙烯单体含量的聚氯乙烯分散体,其改进包括 将所述气体和液体组分的泡沫通过体积不大于所述聚氯乙烯分散体体积的331/3%的密闭空间,并将所述液体成分泡沫体通过细长区域的所述聚合区域的所述聚氯乙烯分散体返回到所述聚合区域中的所述聚氯乙烯分散体 sma 在所述限制空间下面的横截面,并且速率使得所述密闭空间从未完全填充有所述液体组分的泡沫。 根据本发明,通过设置在密闭空间下方的泵将积聚在密闭空间中的液体或泡沫的量泵送回脱气(聚合)高压釜中。 优点在于更好地利用分离能力,更好和更均匀的产物脱气以及更短的脱气循环。

    Gas injecting valve for suspensions
    2.
    发明授权
    Gas injecting valve for suspensions 失效
    悬浮液气体注入阀

    公开(公告)号:US4261389A

    公开(公告)日:1981-04-14

    申请号:US90594

    申请日:1979-11-02

    摘要: A valve arrangement for injecting a gas into a polyvinyl chloride fluid suspension, through an inlet port in the bottom of the suspension tank. The valve includes an overhanging upper disk with a hollow foraminated cylinder, so that the gas exits the cylinder under pressure through the foraminations, thus keeping the operating portion of the valve free of the suspension, with the valve disk overhang providing additional protection against intrusion of suspension material into the clearance space between the valve cylinder and surrounding injection tube. The valve disk overhang terminates in a pointed ridge which engages the top of the injection tube to form a seal.

    摘要翻译: 一种用于通过悬浮罐底部的入口将气体注入聚氯乙烯流体悬浮液的阀装置。 该阀包括具有中空的有机气瓶的悬垂上盘,使得气体在压力下通过该孔离开缸体,从而保持阀的操作部分没有悬架,阀盘突出端提供额外的防止入侵的保护 悬挂材料进入阀筒与周围注射管之间的间隙。 阀盘突出部终止于与注射管的顶部接合以形成密封件的尖锐的脊。

    Process for prevention of foaming when steam-stripping residual monomer
from aqueous polymer dispersions
    3.
    发明授权
    Process for prevention of foaming when steam-stripping residual monomer from aqueous polymer dispersions 失效
    当从水性聚合物分散体中汽提残余单体时,防止发泡的方法

    公开(公告)号:US4224437A

    公开(公告)日:1980-09-23

    申请号:US944404

    申请日:1978-09-21

    CPC分类号: C08F6/16

    摘要: In the process for steam-stripping residual monomer from an aqueous polymer dispersion comprising injecting steam into an aqueous polymer dispersion containing residual monomers and the customary amounts of emulsifiers and/or protective colloids, said dispersion having a solids content of from 15% to 55% by weight with simultaneous evacuation of the gas space above the dispersion whereby said gas space is maintained at a subatmospheric pressure and said residual monomers are volatilized, the improvement consisting of injecting a sufficient volume of steam into said aqueous polymer dispersion whereby from 5% to 50% by weight of the injected steam passes through said dispersion uncondensed, thereby substantially preventing formation of foam above said dispersion.

    摘要翻译: 在从含水聚合物分散体蒸汽汽提残余单体的方法中,包括将蒸汽注入含有残余单体的水性聚合物分散体和常规量的乳化剂和/或保护胶体中,所述分散体的固体含量为15%至55% ,同时排出分散体上方的气体空间,由此所述气体空间保持在低于大气压的压力下,并且所述残余单体挥发,其改进包括将足够体积的蒸汽注入所述聚合物水分散体中,由此5%至50 注入蒸汽的重量%通过所述分散体未冷凝,从而基本上防止在所述分散体上形成泡沫。