What causes the black and yellow spots on the resin?
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Resin with eight consecutive batches exceeding the limits for Hei-Yellow spots in polymerization? Is it due to operational reasons or something else? Is the main reason in polymerization or drying? The polymerization formula is also clean; the polymerization reactor has been heated, flushed, and cleaned, and it is also cleaned regularly? Is there a problem with the heating process in the spray kettle? Other shifts carry out this same operation, yet the resin produced there does not have any black or yellow spots. Also, how can I prevent the formation of black and yellow spots?
What type of resin is produced using what kind of process? How to granulate? This question is way too vague……
This post was last edited and replied to by clq20040107 on 2010-11-28 at 14:35. There are two main reasons for the black and yellow spots on the red resin: one is evaporation, and the other is drying. Stirring: 1. It is caused by impurities in the slurry fed into the stirring tower (due to failure to clean the filter, rinse it, or reverse its operation over an extended period of time). 2. It is caused by excessive temperature control in the stripping tower (mainly the temperature control at the top and bottom of the tower). 3. Residence time of the slurry in the tower. 4. Top pressure of the tower and pressure difference of the tower. Drying: 1. Caused by an excessively high temperature in the drying bed. 2. Caused by the accumulation of aggregates at the bottom of the air duct over time. 3. Caused by a dirty air filter
The problem is likely to lie mainly in the drying unit; a slurry filter should be installed before drying to remove slurry containing black and yellow particles
First, observe what type of impurities they are – whether they were brought in from the outside or generated within the system. Check whether there are any fluctuations in the operation of the stripping unit or any steam leakage through the column; such phenomena generally lead to the formation of impurities, primarily due to color changes in the resin； Next, it comes down to the drying system; air filters and discoloration of the materials within the system over time can both lead to excessive amounts of black and yellow spots. To prevent point overload, efforts must be made in terms of control and system cleanup!
Friend, the standard answer is to use segmented sampling – first take samples from different segments to determine which stage is having problems. Then I’ll tell you how to proceed and what to do next
There are many reasons for the black and yellow spots on the resin: factors such as stripping, drying, monomers, and water. In terms of stripping, it is caused by the temperature in the gas tower; in terms of drying, it is due to excessively high temperatures in the drying bed, accumulation of material at the bottom of the air flow ducts, and a dirty air filter. The quality of the monomer is poor, and the water is not pure
Take samples in accordance with the process sequence, and check things step by step