What to do if the dissolved oxygen level in boiler feedwater is too high?
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Who can tell me what to do if the dissolved oxygen level in the boiler feed water is too high, and what is the appropriate ratio for adding deoxidizing agents?
If the dissolved oxygen level in the boiler feed water is too high, a deoxidizer can be added for chemical deoxidation; such deoxidizers include propyl oxime and hydrazine. For example, the amount of propyl oxime to be used is approximately 5 times the weight of the dissolved oxygen.
Normal thermal deaeration can solve this issue; check whether the water distribution pipes and packing in the deaerator are evenly distributed
Check whether the deaerator is operating under overload conditions; if it is within the specified load, then verify whether the feed water temperature meets the requirements and whether the steam supply volume is sufficient. If everything is fine, then inspect the deaerator’s distribution pipes and packing to ensure even distribution； If it operates under overload conditions, chemical deoxidation by adding chemicals is required
This post was last edited by zgj2405 on 2011-6-5 08:33: increase the temperature of the deaerator appropriately, and also raise the amount of hydrazine added.
If the dissolved oxygen level is high: 1. Check whether the deoxygenation system is operating under overload； 2. Check the inlet flow and temperature control curves, as well as whether the flow and temperature of deaeration steam vary steadily ； 3. During the major maintenance, open the manhole to check whether the nozzles and gaskets are in good condition, and whether the arrangement of the nozzles complies with the specifications ； 4. The temperature and pressure can be appropriately increased to test the deoxygenation effect ； 5. Check whether the sampling device is in good condition ； 6. If the sampling point is at the outlet of the feed water pump, check whether there is any internal leakage in the pump’s seal, as this can also lead to high dissolved oxygen levels. The dosage of the additive needs to be determined based on the water quality and actual production conditions. These are just some of my experiences; I hope they can be helpful to you.
If the dissolved oxygen level is high: 1. Check whether the deoxygenation system is operating under overload； 2. Check the inlet flow and temperature control curves, as well as whether the flow and temperature of deaeration steam vary steadily ； 3. During the major maintenance, open the manhole to check whether the nozzles and gaskets are in good condition, and whether the arrangement of the nozzles complies with the specifications ； 4. The temperature and pressure can be appropriately increased to test the deoxygenation effect ； 5. Check whether the sampling device is in good condition ； 6. If the sampling point is at the outlet of the feed water pump, check whether there is any internal leakage in the pump’s seal, as this can also lead to high dissolved oxygen levels. The dosage of the additive needs to be determined based on the water quality and actual production conditions. These are just some of my experiences; I hope they can be helpful to you.