Regarding the issue of high initial reactor pressure in the polymerization reactor
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I have a question: For 70m3 polymerization reactors, recently it has been observed that the initial reactor pressure is on the high side after feeding the material into the reactor – it is 0.03–0.05 MPa higher than before. This phenomenon occurs in all of these polymerization reactors. We conducted a self-check on the soft water flow meter feeding into the reactor, the feed wash water flow meters (for dispersant and initiator), and the water injection flow meter at the bottom of the reactor – all of them showed no abnormalities. The pressure on the DCS is also consistent with the pressure gauge on site. The viscosity number of the PVC resin is also normal, which should indicate that the temperature in the polymerization reactor is also normal. Since the resin particles are normal, it can also be inferred that the amount of monomer is normal. I earnestly ask for guidance from experts; thank you!
The inert gas has not been completely removed. Such as nitrogen.
This is mainly caused by inert gases; in winter, the exhaust pressure at the condenser is lower and cannot match the set pressure in summer, so more inert gases need to be released.
Our factory also encountered such a problem before; inert gases are one of the causes. Another reason is the temperature of the circulating water
For a 70-cubic-meter reactor, if there is no cooling at the top of the reactor, then no nitrogen will be introduced into the entire system! I wonder if the owner’s unit has a top-mounted cooler! Several reactors are experiencing this issue; either the public measurement instruments are not functioning properly, or the temperature of the soft water fed into them is higher than usual.
The real problem is that the temperature of the soft water used for feeding is relatively high, which causes an increase in the saturated vapor pressure of the monomer
Has the reaction time also increased a bit? The replacement wasn’t done thoroughly. The method is to adjust the recovery pressure to its lowest level and carry out a thorough recovery and replacement process, to remove gases such as air from inside
The temperature of the soft water used for feeding is not high; when producing SG-3 resin, the temperature of the hot water is 78–80℃
The last edit to this post was made by tfx511024 on 2012-1-19 at 17:59. Reasons for the increase in initial reactor pressure: 1. Inert gases – this is an increase in initial reactor pressure caused by inert, non-condensable gases; attention should be paid to the pumping pressure and vacuum level, and it’s important to verify the instruments as well as the on-site primary meters carefully. 2. The increase in the temperature of the material entering the reactor leads to a higher saturated vapor pressure at that location compared to what was previously estimated, which results in an increase in reactor pressure after the initial feeding. Make sure to check the thermometer. By examining the relationship between the saturated vapor pressure of a material and temperature, relevant parameters can be obtained. 3. Check whether the formula includes volatile additives. 4. Whether the instrument needs to be recalibrated. 5. Are there any minor leaks in the process pipelines, such as those related to nitrogen purging?
After the discharge from the polymerization reactor was completed, the purity of the gas phase inside the reactor was measured to be over 94%, so the recovery efficiency is satisfactory