Boiler water dissolved oxygen content is too high
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The methods of increasing temperature, increasing pressure, adding N2H4, opening the deaerator vent valve, etc. have all been adjusted and the dissolved oxygen content has always been high. Have any of you encountered a similar situation?
I guess your deoxidation tank is running overload. Have similar problems occurred before this phenomenon occurred?
I have looked for the reasons you mentioned. Then it depends on whether there is a problem with the analysis or the equipment, or the quality of the hydrazine.
First, check whether the temperature is around 104 degrees and whether the concentration of the hydrazine solution is low? It is usually around 1%. Has the quality of hydrazine been checked? Also, are there any problems with the analysis mentioned on the third floor?
Are there any problems with the deaerator internals? Is it because the feed water and steam cannot fully and evenly contact each other, resulting in poor thermal deaeration effect?
Reply 4# 654262293 I mentioned it when the temperature was around 130.
Now the oxygen is not that high, the operation and adjustment are somewhat inappropriate, and there are also some problems with analysis.
As long as the problem is solved, ammonia is very broad and profound, and sometimes a small problem can defeat an experienced expert. The pH value of our boiler water has been continuously low, only about 8.5. I don’t understand the reason? Everything is normal, including the water supply.
The temperature measurement point of the deaerator is more particular. If the temperature measurement point is below, 100℃ or above is enough. If the temperature measurement point is above the defogger, it must reach 104℃. The pressure does not need to be too high. This has happened to us before. The main problem is internal parts. The water takes a shortcut and the steam cannot heat the return water and directly enters the water tank. You can ask the manufacturer to take a look. In addition, check whether your water seal is connected correctly. This is critical.
Our factory is now trying to air separate excess nitrogen and use the original deaerator to remove oxygen at low temperature. The effect is good and can save 3-5 tons of steam. Everyone is welcome to try it! Moreover, the steam deoxygenation effect is better compared with the same period last year, and the dissolved oxygen in some samples is less than 10ug.
Our factory has also had the same problem as the original poster, and so far it still often exceeds the standard. I have also tried increasing the temperature, increasing the pressure, adding N2H4, and opening the deaerator vent valve. I have also checked the distributor and deaerator head in the deaerator. It turns out that the load of the deaerator is only about 90% of the design, which is still excessive. Generally, it can only be 7-8 micrograms, and it is difficult to be less than 7. There will be a big deviation in the analysis. We have tried it before. Different people got different results with the same equipment at the same time, and the results were very different.