【Polypropylene】Reasons for the high amount of powder in loop-type polypropylene T502
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This post was last edited by Xiao Gong 1985 on 2016-5-15 08:54. In the process of operating the loop reactor, there is a particularly large amount of powder of T502. Apart from the catalyst being a possible cause, are there any other reasons? ! No powder discharge from T501!
Is it a blockage in the material discharge for S502?
How to determine a blockage in the S502 feeding system? ! Question!
1. Poor material discharge at S-502. Based on the outlet pressure of C-801, it can be determined that there is a pulse each time D-507 discharges material; the outlet pressure can be observed through the curve to make this judgment. When moving in a straight line or when the pressure change is minimal, it can be preliminarily concluded that material feeding is poor. Treatment method: D-507 backblowing 2. Reasons for excessive fine powder: It is related to the pre-polymerization effect, as well as the polymerization temperatures of reactors 201 and 202, and the temperature at which flash evaporation occurs. When there is a large temperature difference, the catalyst may be damaged; as a result, more fine powder is produced during polymerization
1. What is the nitrogen pressure before the HV530C valve for you? ! 2. What are the set times for valves A, B, C, and D? ! 3. Our prepolymerization temperature is 10, what about you? ! The loop tube temperature is around 69.x to 70! 4. Our catalyst is fine, including the preparation process! 5. After preparing the catalyst, did you shut down A106A\B? !
1. The pressure after pressure reduction before the valve is around 0.13. 2. The feeding time for S-502 is 600 seconds, while that for D-507 is 15 seconds. 3. The temperature range: the pre-polymerization temperature is 18.5–20 degrees, and the temperature of the loop reactor is controlled at 68–70 degrees. 4. After the catalyst is prepared, A-106 remains in operation continuously. After configuration, the temperature remains around 8 degrees.
? ? ? ? ? No! ! ! Solve!
1. Pressure after the valve: 0.3 MPa； 2. The unloading time for S502 is 60 seconds, while it is 24 seconds for D507 (if I remember correctly). 3. For pre-polymerization, T10; for the loop reactor, it’s around 69 degrees – that’s basically the temperature at all the measurement points ； 4. After configuration, stop A106, T, 10-13 ； Chilled water at around 3 degrees. A. Is it related to the pressure after the valve? ! B. At the beginning, the time setting was similar to that mentioned above; there was a lot of powder, and the pressure behind the valve was 0.7 MPa at that time ； It does matter whether the pressure is high; what is a reasonable pressure downstream of the valve? ! C. The nucleating agent mentioned upstairs has not been used, but in the two state-owned enterprises I’m aware of, A106 is always in use! But other people don’t have much powder, so they might need to retrieve it once every half month to a month! D. Moisture content of the powder? ! How did you all solve it? !
1. The pressure is too high; at the moment the valve opens, a pulse of air flow is generated, which affects the cyclone as well as the T-502 washing process. 2. The duration of the material discharge process is adjusted according to the amount of powder present, and it varies from one installation to another. 4. Treatment for high moisture content in powder materials: (1) Increase the amount of D-501 steam used. Check whether the drain from the three steam lines contains liquid. Adjust whether the amount of steam supplied to the vaporization unit is too high, as well as the saturated vapor pressure of steam at the corresponding temperature. If it is higher than the steam pressure corresponding to that temperature, steam will carry liquid with it, causing the powder to become moist. (2) Check the three make-up water valves using instruments, and verify the valves. (3) Increase the temperature of the dry nitrogen. At the same time, check the condensate drain at the fan outlet to see if there is any free water. Increase the bottom drain of D-508 and reduce the washing temperature of T-502. Whether it is the specific content or the moisture level of the powder, these are just superficial issues; identifying the root cause and taking appropriate action is necessary to resolve the problem (the above are merely my personal opinions for reference only)
When we discharge steam at D501, powder materials can clog the filter, so it needs to be removed and cleaned after some time. Is there a leak in the equipment? The jacket drain can also get clogged! The amount of powder used is a bit less than during operation, but it’s still relatively high. Based on my assessment, I think the pressure before the valve is too high, at 0.3 MPa. Secondly, the timing of I508 has not been properly adjusted to a interval suitable for the operation of our device (a problem at the management level). Third, the level of material in D502 may also cause powder to enter S502, increasing its load and reducing its separation efficiency. Fourth, the nitrogen volume for D502 is too high. The powder material will also be taken into S502. V. The processing capacity and inlet pressure of S502. Sixth, the temperature in D201 is low, at 10 degrees, while that state-owned enterprise keeps it at 15 degrees. The powder contains moisture; it is said that steam condensate was used for cooling some time ago.