The condition of the evaporator valves is not very good; let’s discuss this
Thread Content
Hello everyone. There are several types of evaporators available (multi-effect, single-effect, MVR), and the materials used include sodium chloride, sodium sulfate, as well as solutions of calcium chloride and magnesium chloride. The discharge valves used in thick liquid handling, as well as the valves for self-circulating discharge and those located in rotary systems, have not been very reliable. Fluorocarbon-lined ball valves and 2205 soft-seal ball valves have been used; after half a year to a year, corrosion and erosion wear occur. Even titanium hard-seal ball valves have been tried, but they became problematic after one year of use. I would like to know how other professionals handle this issue – are there any good solutions?
Given that your medium appears to be quite viscous and contain many particles, its corrosivity is likely not very high, right? Fluorinated linings definitely won’t work; they aren’t wear-resistant. The main considerations should be wear resistance and resistance to sticking, so a wear-resistant V-ball valve could be an option to consider
Based on what you said, I’ll briefly outline the valve options that could be used: eccentric rotary valves and plunger-type material valves. The medium you mentioned has particles, is highly corrosive, and is viscous. If the viscosity is very high, a jacketed heater can be used to reduce it. However, it would be fine to use your fluorinated valves for half a year to a year before replacing them; from a cost perspective, that’s a good option.
This post was last edited by Instrumentation and Automation Design on 2022-12-7 at 12:48. Corrosion is severe; acid washing is required every little over a month. Can a hard-sealed V-ball solve the problem of scaling and sticking? Is the hard-seal stuck? Soft seals are not wear-resistant
If you’re using pickling treatment, then special materials are necessary; they are expensive. Imported DN50 units cost around 100,000 yuan. I’m not sure if your company can accept that price. If that doesn’t work, the fluorinated lining has to be replaced regularly.
How can centrifugation be carried out if the viscosity has decreased? It’s complete nonsense
The material contains sodium chloride, which is highly corrosive; how can corrosion protection be ignored?
One year of use for titanium materials – is that not enough? Typically, such valves last for at most half a year; those lined with fluoroplastic generally have a lifespan of 3 days, 316L variants last 10–15 days, and those made of 2507 last 1 month.
Ceramic valves are more suitable; they are wear-resistant, corrosion-resistant, and do not get clogged