How to eliminate scaling in the tube layers of the first-stage and second-stage urea heaters.
Thread Content
Please discuss: how to eliminate scaling in the tube layers of the first-stage and second-stage urea heaters. This post was last edited by ymtuegj12 on 2009-2-19 08:36.]
The best method is to use a high-pressure water gun for jet cleaning; it is the best approach we have identified after repeated experimentation and attempts
I think we should consider the causes; the main component of the scale layer is sludge, and the source of this sludge is primarily urine as well as air compressors. The oil content in urine comes from various high-pressure pumps, ammonium carbonate tanks, and raw carbon dioxide – so it’s quite clear where control measures should be applied.
What was said on the 3rd floor is correct; however, no matter how well control is exercised, some oil will still enter the system and carbonize to form scale inside the heat exchanger (in the high-temperature area), which affects heat exchange. Once scaling occurs, the system must be shut down for cleaning. If the scaling is not severe, it might be possible to clean it off using a high-pressure water gun. But if the scale layer is thick, it is difficult to remove it with a high-pressure water gun in such cases, and chemical cleaning could be considered. There are professional cleaning services available, or a combination of high-pressure water guns and chemical cleaning can be used.
High-pressure water is still the better option, though the pressure needs to be quite high, around 60 to 80 MPa. If the scale buildup is thick, an even higher cleaning pressure is required, which makes the process time-consuming and labor-intensive. The issue of oil in air compressors is difficult to deal with; people are reluctant to spend money on oil-free versions, so they have to use more force. It would be great if there were an air separation unit available.