Regarding the loading and unloading of concentrated sulfuric acid
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Currently, work is being carried out on the design of the loading and unloading system for the tetrachloroethylene project, which involves the unloading of 98% concentrated sulfuric acid and the loading of 88% concentrated sulfuric acid. I would like to know what special precautions are required when handling these two types of sulfuric acid, such as the handling procedures, anti-corrosion measures, and considerations related to piping. Could you provide some information on the relevant handling processes? Thank you!
Thick solutions don’t require preservatives; thin ones are handled by the village authorities
Plastic lining with dilute acid, personal protective equipment during loading and unloading
It depends on what category your product falls into, such as ordinary industrial acids or battery acids. From the perspective of long-term operation and investment, the use of fluorinated-lined pipes results in a relatively lower iron content in the products, and they should be able to function properly for ten years; ordinary pipes start to leak acid after just over a year. During design, consideration should also be given to loading and unloading efficiency as well as the tank capacity. From a safety perspective, there should be a buffer tank or a small storage tank between the pump and the acid discharge outlet. A drain pipe also needs to be installed at the acid outlet to prevent the acid from dripping onto the ground after loading is complete.
Reply to 4# zrf1987: Question: 1. Will using Q235A pipelines for 98% concentrated acid still result in acid leakage after 1 year? 2. If a flow meter is used during loading, are buffers and metering tanks still needed? How does the drain tube on the flexible hose function? Thank you
1. Whether there will be leakage in 1 year depends on the flow rate and wall thickness. Generally, leaks occur easily at the elbows and behind them, but they usually don’t last just 1 year. It is recommended to use material of 304L or higher at the elbows, and to install leak-proof cloth or \"jackets\" on all flanges and welds. 2. A buffer tank is not necessary, but it is essential to ensure that any remaining acid in the pipe after filling can be discharged somewhere. 3. Ensure that the flow meter has sufficient straight pipe sections; choose imported or joint-venture brands, and opt for a higher level of accuracy whenever possible. An electromagnetic flowmeter or a mass flowmeter is recommended. However, the service life of mass flow meters is relatively limited.
Thank you for the prompt reply from the 6th floor. I’ve also looked up some information these days, but I’m still confused regarding the anti-corrosion issues of pipelines 1. For 98% industrial-grade concentrated sulfuric acid, if Q235A is used for the pipelines, what should be the minimum wall thickness required? What is the acceptable safe flow rate? I once read an article on Cai Haichuan’s website regarding the corrosion of carbon steel by sulfuric acid; it stated that it is necessary to strictly control the flow rate of sulfuric acid. DuPont’s data indicates a range of 25–70 mm/S, while design recommendations suggest 50 mm/s. If this standard is followed, a DN150 pipeline can only handle a flow rate of 3.18 m3/h. Yet the natural flow rate of sulfuric acid is faster than this, so how can it be loaded and unloaded? 2. I have also seen many articles discussing the requirements for welds and elbows. The specific reason? What about improvement measures? Thank you all for your help!