Help! Solutions for red color of boiler water in low-pressure boilers
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We have 2 steam boilers, each with a capacity of 20 tons and operating at a pressure of 0.5 MPa. Last September, the chemicals used in these boilers were replaced; instead of trisodium phosphate, a new type of chemical was used, one that offers multiple functions such as deoxygenation, scale prevention, and pH regulation. This new chemical does not contain phosphates. At the beginning of its use, the water in both boilers became cloudy and took on a red color. After carrying out waste discharge procedures, the water in Boiler No. 1 returned to normal, with no phosphates detected and all other parameters within normal ranges. However, the water in Boiler No. 2 remained red and cloudy, with phosphate levels reaching 5, and sometimes even around 10. The situation worsened when the boiler was restarted after being shut down, and increasing the amount of waste discharged did not yield satisfactory results. Recently, there has also been an abnormal increase in the pressure in the steam drum. We seek advice from experienced technicians to understand what is causing this issue and what solutions can be applied. Urgent! Urgent! Urgent!
Check carefully to ensure that the waste discharge is effective. Talk to the pharmaceutical manufacturer for guidance. The new chemical does not contain phosphorus, and the current high phosphate level in the boiler water is likely due to scaling that occurred previously inside the boiler. Could an abnormal increase in steam pressure be due to an improved heat transfer effect after scale removal? If you are concerned, you can reduce the amount of the new chemical added gradually; once things return to normal, you can resume the normal dosage. During this period, continue to increase the amount of waste discharged
Thank you for your suggestion! I talked to the manufacturer before, and they said to increase the amount of waste discharged; if that doesn’t work, then reduce the dosage of chemicals first, and resume normal dosing once the water quality returns to normal. The main issue is that the two furnaces differ significantly from each other. If scaling is the problem, it’s possible that one of the furnaces is suffering from more severe corrosion. With the scale falling off, there is a concern that tube leaks might occur later on, which could affect production. After all, it’s difficult to carry out maintenance during winter.
If the furnace tubes become fouled, they will overheat and have a shorter lifespan. Scale is not a coating; it has very low strength, and one cannot rely on it to prevent leaks
Dude, the new phosphorus-free agents have been in use for almost 2 years now. How effective are they, and are there any drawbacks? I’ve just started using them here, so I’d like some advice
I haven’t been here for a long time; I just saw it. It works well; during the major repair last year, the old piping was replaced, and now the water quality parameters are normal. There has been no more occurrence of the boiler water turning red.