Compilation of Case Studies on Solving (Accident) Issues in Sulfuric Acid Production Technology

It’s difficult; the specific manufacturing processes and parameters are hard to describe clearly in just a moment. Let me not go to work and focus on writing full-time; it will probably take about three to five years.

This post was last edited by yi*aofei001 on 2010-9-5 09:20. In 2008, Liu Shaowu wrote a book titled \"Causes and Solutions for Abnormalities in Sulfuric Acid Production,\" which provides a fairly comprehensive overview. You don’t need to write down everything you know; just include anything that comes to mind at any time or that is particularly memorable to you. It’s really frustrating when you encounter problems that can’t be solved, but once you manage to resolve them through your efforts, you’ll feel a great sense of accomplishment. The greater the difficulty of the problem, the higher your sense of achievement.

This post was last edited by Oath-taking on 2011-10-12 08:49. Let me start with one. A problem that arose just a few days ago: the finished product with 105% nicotinic acid content cannot be transferred to the large tank for storing finished products. (The pipeline leading to the finished product is a branch that comes off from the acid pipeline in the upper tower; the pipeline leading to the absorption tower does not have any flow meters or valves.) Relying entirely on a diaphragm valve at the pump outlet to regulate the flow rate (i.e., the pump current), I first assessed the possible sources of problems: 1. There may be blockages in the pipelines (as in the past, the mortar that seeped out from the gaps between the bricks used in building the circulation tank had blocked the acid delivery pipelines in that tank). 2. The valve core has fallen off. 3. There is a problem with the acid pump. Subsequent checks were carried out: blowing the pipelines with compressed air confirmed that they were unobstructed, and inspecting the valve stems during pipeline disassembly showed no issues; current measurements also indicated that there were no problems with the acid pump. For two consecutive days, this problem has not been resolved, and the cause of the issue has not been identified either. I really have no idea what to do anymore; I even replaced the acid pump with a spare one, but the problem still persists. At this point, we have to consider the worst possibility: could there be a problem with the tubular acid separation device inside the absorption tower, such as the acid separation holes becoming larger or there being an issue with the gaskets? Although the likelihood of problems occurring in this place is relatively low or even impossible, it still needs to be taken into consideration. Immediately replace the pressure gauges at the inlet and outlet of the acid cooler to measure the height of the finished product tank, calculate the pressure required to send the material to that tank, and conduct a comparison. The comparison result shows that the indenter is insufficient. But it’s not possible to stop the machine for inspection; therefore, maintenance personnel were immediately coordinated to connect a pipeline from the pump outlet to the valve that regulates the pump current, thereby linking it indirectly to the pipeline leading to the finished products. After 48 hours, 105% nicotinic acid was used to restart the operation. This approach can only solve problems temporarily; it is not a solution for the long term. First, the finished acid enters the large tank without being cooled, resulting in excessively high temperature that affects the service life of the pipelines and storage tanks. Second, the real cause has not been found; it is only a suspicion. Sometimes there’s really nothing you can do. This method is strictly speaking not advisable, but it can maintain production.

Why was the outlet pressure of the finished product cooler sufficient in the past? Hehe, I guess I went in the wrong direction. Since a spare pump has been installed, it indicates that there is no problem with the pump. I guess it’s very likely that there’s a problem with your cooler – is it a plate-type cooler or an anode protection system? Open the inlet of your cooler and check it; it might be blocked on the acid side, or it could be due to an air blockage – there is gas inside the cooler, which causes this air blockage. If you suspect a problem with the tower, then check the absorption rate; if the absorption rate is fine, it’s impossible for there to be such significant acid leakage inside the tower. Another question: Why is a diaphragm valve being used? ? ? ?

This post was last edited by yi*aofei001 on 2010-9-5 at 16:54. The main unit’s air circuit valves cannot be closed properly, so it’s not possible to open the cooler for inspection at the moment. If the cooler is blocked, the pump current won’t increase either; however, we’ve tested and found that the current of the acid pump is normal. There is also an electric control valve behind the diaphragm valve to regulate the flow rate to the storage tank. The solutions mentioned above are those that can be implemented without affecting the system’s operation.

This post was last edited by Oath-taking on 2011-10-12 08:50. Does your pump outlet have two parts? One part goes to the cooler and then to the acid tank, while another part goes into the tower for circulation? How much is the amount entering the tower, and how much is entering the acid tank? The amount entering the acid tank is estimated to be much smaller than that entering the tower; how could it possibly affect the pump’s current? Moreover, when the amount of coolant decreases, the amount entering the tower naturally increases. Can this be determined from changes in current?

The last edit to this post was made by yi*aofei001 on 2010-9-7 at 09:01. Reply to 7# binghe0374: The acid fed into the tower and the acid fed into the finished product tank are both cooled by acid coolers! So there is no such question as you mentioned above.

Personally, I think it’s the acid cooler that is clogged (not completely blocked).

I think it’s better to wait until the vehicle is parked for maintenance to draw a conclusion; I will inform everyone once we have one. This post is a compilation of production technology solution cases; please put some effort into it and stay on topic.

It’s likely that the finished acid cooler is blocked