Synthetic VCM
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Why is compression performed before synthesizing VCM, and in how many stages is it carried out? Why is a pre-machine cooler used before compression? What is the principle of the pre-machine cooler? This post was last edited by shizhiyong001 on 2009-3-25 14:57.]
1. After compression, cooling is carried out to liquefy all of the monomer; at 0.5 MPa, the liquefaction point of vinyl chloride is 46°C, which enables distillation to take place； Old-style piston compressors require two stages of compression, while modern screw compressors can meet the system requirements with just one stage of compression. 2. Function of the pre-compressor cooler: First, to increase the gas extraction volume of the compressor; second, for cooling and dehydration. It is generally cooled below 10°C.
The properties of the material determine the process selection, which is the standard production method.
It is recommended that the poster first become familiar with the properties of the materials, as things will be easier thereafter.
We’ve learned it; the original poster solved the problem, and we newcomers have also acquired knowledge
If compression is not carried out, a large amount of cooling energy is required to liquefy the vinyl chloride gas, and this results in high energy consumption
It is recommended that the original poster consult books such as \"Polyvinyl Chloride Technology\" or \"Production and Operation of Polyvinyl Chloride\"; these books provide explanations to the questions raised by the poster
I think there might be something wrong with what the building manager asked Or am I misunderstanding something? The compression of VCM takes place after synthesis, that is, after the converter and not before it; the VCM after synthesis passes through a mercury remover, a foam sieve tray tower, a water wash tower, and an alkali wash tower before reaching the pre-cooler before the machine. As I understand it, precoolers serve two main purposes. The first is to lower the temperature of the gas in order to improve the efficiency of the compressor (which I think is the main factor); since for a compressor operating according to the equation PV=NRT, the amount of gas drawn in at a given pressure and volume is inversely proportional to the temperature. The second purpose, I suspect, is to prevent the high temperature of the gas after compression from triggering polymerization reactions Or could it be dangerous? Second, some of the water needs to be removed, as water has a significant impact on the system. As for why compression is necessary, it is mainly for liquefaction. There are two methods for liquefying gases: reducing the temperature or increasing the pressure. To save cooling energy, increasing pressure is a more feasible option; of course, the temperature must be below its critical temperature for liquefaction to occur. Therefore, compression is used primarily to remove impurities from the high- and low-boiling towers.
Yes, it is compressed after synthesis; what I mean is the compression before it enters the distillation tower. Sorry, that was a typo……:$
The main function of pre-cooling is to remove moisture from the crude VC gas coming from the purification system; if the gas contains liquid, it can damage the compressor. Introducing moisture into the distillation system can cause it to polymerize, thereby blocking pipes and tower equipment.