Is the resistance of the absorption tower normal?
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For a 200kt/a sulfur-based sulfuric acid production plant, the diameter of one absorption tower is 4700 mm; the absorption pump used is of the JHB450-30 type, and a fiber mist eliminator is installed. Is it normal for the pressure drop to be only 1000 Pa? An acid discharge nozzle is installed at the inlet of the third shell side, capable of discharging 300–350 ml of condensed acid per day. I hope an expert can give some guidance. Thank you.
The resistance feels a bit low. Do you often analyze the amount of acid mist at the exhaust port?
It depends on what percentage of the system’s designed airflow you are achieving. If the airflow is low, 1000 Pa might be sufficient; but if the airflow has reached more than 2/3 of the designed level (under normal conditions for acid spraying), then 1000 Pa would be too low.
200kt/a, with a daily production of 560 tons. Mainly, acid piles were not installed in the previous years; this phenomenon did not occur during the first three years of operation. It is suspected that there is a problem with the fiber mist remover
The resistance of the fiber mist eliminator cannot be less than 1000 Pa either
The last edit to this post was made by chuanhengmpq on 2016-3-28 at 11:25. The DCS shows a pressure of 9.024 kPa at the inlet of the first absorption tower and 7.9 kPa at its outlet; when using a U-tube manometer, the pressure at the inlet of the first absorption tower is 11296 while it is 8263 at the outlet. The instruments are broken again
Trust the results of the U-tube manometer
If the instrument readings deviate from normal values, a U-tube gauge is used for measurement; the U-tube gauge operates on a principle-based method and provides very accurate results. As a supplementary point, a pressure difference of 1000 Pa for fiber mist eliminators has also been observed; this value is related to factors such as air volume, temperature, acid mist concentration, filtration area, and the material of the fibers. I can help you calculate it specifically.
By replacing the fiber foam remover, the system resistance changed, and the previous balance was disrupted; it is necessary to readjust this balance. Using the previous air volume, the outlet pressure decreased while the air volume increased significantly. It’s inevitable that acid will be present in such a situation. When carrying out chemical production, it is essential to pay attention to maintaining balance – this is a simple principle that does not require any calculations. It is sufficient to keep the previous inlet negative pressure; the negative pressure should not be too high, as this would equivalent to increasing the air volume
There is a high possibility of a short circuit in the fiber bed. Recently, I was on a business trip near Xi’an, and I heard from a client that an expert from a sulfuric acid plant had been hired. This expert went inside the second absorption tower equipped with full protective gear to examine the domestically produced fiber mist eliminators, and observed that the fiber bed sank due to the presence of acid. After stopping the operation and removing the fiber mist eliminator, the fiber bed returns to its original state as it loses the acid retention capacity.