Can a second-stage drying tower be added?

It should be possible; however, two drying towers can share one circulation tank. The control of the acid circulation process remains the same as before, and the circulation tank can be enlarged

Theoretically, it should be possible; in practice, however, it is not scientific. It is necessary to identify the reasons for the excessive levels of moisture and acid mist, and install electrostatic mist eliminators to remove such acid mist.

Disagree! The reasons are as follows: 1. The setup for two-stage drying is quite precise; the concentration of acid in the first stage must be maintained at around 76%, otherwise the results will not be good! It’s like two people are each able to drink half a jin of alcohol. When 6 liang of alcohol passes through these two people in sequence, the first person drinks half a jin, while the second person only gets 1 liang – clearly, this represents a waste of capacity! 2. Using two additional drying stages increases energy consumption and the number of equipment, which is not beneficial for production control. If there is money to add a drying tower, it would be better to upgrade the existing one instead.

It’s not necessary; no matter the scale of the sulfuric acid production facility, primary drying is more than sufficient to meet the process requirements. The question is: are there any issues with your company’s drying setup? If so, they need to be addressed at their root cause.

I agree with Pinzhi’s opinion. Find the real cause and address it accordingly! ! ! The reasons are nothing other than electric demisting, inlet temperature for drying, foam catchers, and the concentration and temperature of the circulating acid.

There’s no need for that; it’s a waste of resources. One drying tower is sufficient. It’s necessary to identify the real cause and then take appropriate action, which will resolve the problem.

The purification process for sulfuric acid production in our plant follows a wash-and-rinse procedure using water; it is an old facility from the 1960s. After several upgrades, its current annual sulfuric acid production capacity is 40,000 tons. The main reason for this situation is that our plant uses some ferrous sulfate with a high moisture content in its production process; hence, as I mentioned at the beginning, it is not possible to make significant changes to the current operating conditions. I am very grateful for your sincere guidance.

It’s still the water washing and purification process; it would be better to change \"wen pao wen\" to \"wen pao jian dian\" or \"wen wen jian dian\", and then the moisture and acid mist levels will be within acceptable limits.

Change it to the text--soak--electricity process. The foam tower needs to be adjusted according to the operating conditions; it is used in a water washing process, so an intercooler is not required.

The electro-water washing purification process was developed by the late Mr. Sun Shibai from the former Shanghai Sulfuric Acid Plant; it is used for the washing and purification of sulfuric acid produced from pyrite in capacities of up to 100,000 tons. It requires less wastewater, and even in hot weather it enables the acid mist to meet the required standards. This process has been in use in Suzhou for twenty years.

Exceeding the moisture specifications at the outlet of the drying tower is a common phenomenon, and its negative consequences are quite evident. Such as the degradation of the conversion catalyst, blockages in the pipes due to wear and tear after three or four replacements, corrosion and imbalance of the main fan impeller, and smoke emission from the chimney. According to the introduction of the sulfuric acid industry by the Shanghai Sulfuric Acid Plant in 1989, it is best to keep this value at 0.05; there is a precedent of operating without shutdowns for one entire year. But in reality, there are many cases where the moisture level exceeds 0.1. Currently, there are methods to modify the filler, to alter the acid distribution devices, to reduce the inlet air temperature, as well as the use of demisters after drying. There are also issues related to air leakage in the pipelines, and adjustments are made to the amount of acid pumped in and to the acid concentration. But I’ve never heard of connecting dryers together before; it’s definitely not necessary.

Rather than adding another drying tower, it is better to carry out a comprehensive acid cleaning and renovation of the purification system.

It’s better to thoroughly examine and analyze the current operating parameters in order to identify the root cause and take appropriate action – check the acid concentration, the amount of acid added, and whether the acid distribution is even Is the packing filled properly? Is the height sufficient, and are there any short circuits? Is there a leak in the negative pressure pipeline? Wait. If these issues are not resolved, it’s pointless to use even two more drying stages.

I want to say what everyone else has said: there’s no need for secondary drying.»

There’s nothing to do about it – some small enterprises have to grow gradually from a capacity of 10,000 tons; it’s extremely difficult. The problems mentioned above are mainly due to too high gas velocity in the drying tower, high resistance inside the tower, and severe foaming at the outlet. I’ve been to a factory where the moisture content was as high as 0.8, yet the exhaust gas seemed fine; the issue was simply the severe foaming. You could consider replacing the packing with structured packing, or installing another drying tower in parallel – series connection isn’t feasible. Replacing the two-stage system with an electrostatic mist system can resolve both of these problems.

Using two levels of drying is not advisable. Rather than spending money to upgrade the drying level, it’s better to invest in an additional level of electrostatic fogging, or an additional level of power waves (power waves generate significant resistance, so the fan needs to be modified) ； The electrical fog resistance is not too high; if the fan has sufficient capacity, no modification is necessary). In fact, the most cost-effective option might be to optimize the existing system, or to modify or replace the current purification equipment.

Everyone’s analysis makes sense; the original poster should also consider the situation carefully. :lol

Theoretically, it is feasible; by identifying the cause, one can install a wire mesh demister in the drying tower to see if that can solve the problem.