What is a good cleaner for cleaning the brine heater E153?
Thread Content
This post was last edited by sunjl1981 on January 6, 2013, at 22:11. Recently, it has been difficult to raise the temperature of the brine in the E153 brine heater. Upon disassembly, I found a layer of scale along the brine pathway. What is the main composition of this scale? The heater is made of titanium; what kind of cleaning agent would be suitable for it? # hcbbs
During the heating process, whether heated with hot water or steam, most of the impurities are rust and scale, which can be removed through acid cleaning. At low temperatures, most of the scale consists of divalent metal compounds such as magnesium hydroxide, calcium carbonate, barium sulfate, and barium carbonate; this can be addressed through acid washing. The problem is that for plate heat exchangers, online acid washing isn’t an ideal method; instead, they must be disassembled for individual acid washing. For a plate heat exchanger with a surface area of 160 m², two people can complete the process in just half a day.
Soak in dilute hydrochloric acid with a corrosion inhibitor for 10 minutes, then scrub with a brush, and finally rinse thoroughly with clean water.
Our E-153 is a shell-and-tube heat exchanger; its tubes are made of titanium, while the shell is made of Q235 steel. The tube side is treated by soaking in dilute hydrochloric acid. The steam on the shell side is relatively clean. Basically, there’s no need to remove dirt
Apart from divalent metal precipitates, which are presumably mainly crystalline salts, recently the concentration of the secondary brine has always been on the high side, and the scale layer is very resistant to removal. After adding hydrochloric acid and allowing it to circulate for 6 hours, some degree of cleaning can be observed; normally, a 3-hour treatment with hydrochloric acid is sufficient to remove such scale layers. Why is crystalline salt so hard, and why does it dissolve so slowly? Please share your thoughts on how its structure differs from that of industrial salt
The shape of sodium chloride crystals has not changed much; however, due to the absence of impurities, the crystals are continuous and dense, making it easy for them to form a single mass within the pipeline. As for the dissolution speed, hehe, that’s because the water temperature isn’t high enough. It is recommended to use low-pressure steam to dissolve the salt deposits directly. Don’t make the concentration of the brine too high either; 310 is sufficient.
For shell-and-tube heat exchangers, high-pressure water jet cleaning can be considered. It doesn’t damage equipment and causes no pollution.
They need to be separated one by one for cleaning; the online cleaning effect isn’t ideal.
For our saltwater plate exchangers, online cleaning is used, but the results aren’t very good； Remove for cleaning; installing the back gasket can lead to leaks
In the shell side, this problem can be resolved by washing with dilute acid mixed with a corrosion inhibitor. Care should be taken to control the pH level; generally, it should not be lower than 2； Because it’s heated with steam, there’s mostly rust. In a monitor, high pressure can be used