Water quality issues in circulating water systems
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The circulating water tank is filled with a large amount of foam, and its turbidity is very high. The oil content is normal, and there are no obvious leaks in the heat exchanger. The cod content is high. A large number of replacements are being carried out at present, with poor results. Dear experts, what is the cause of this?
What factory? Isolate the heat exchangers that are suspected to be the problem, and then the source of the leak can be identified. The media in our plant becomes acidic when it comes into contact with water; therefore, pH meters are installed in the recirculating water return pipelines. Once acidity is detected, we immediately drain the water from the heat exchangers that tend to leak, in order to check them on site. You refuse to accept anything and just ask for reasons; who the hell knows the background or circumstances?
Treated by oxidation method – no water change required, no chemical additives needed, automatic sludge separation, with turbidity reduced to below 1.
A high COD level definitely means there’s a leak somewhere; it can’t appear out of nowhere. The amount seems quite significant, so it’s necessary to investigate promptly.
At the refinery, we took samples from the inlet and outlet ports of more than thirty heat exchangers in their aqueous phase, and analyzed them. By comparing the values at the inlet and outlet, we found that the COD levels differed by little, and no significant leaks were detected. Is there any way to directly detect what substances in the water are causing the COD level to be too high? This way we can conduct targeted inspections; otherwise, there are too many heat exchangers to monitor effectively.
It has persisted for a long time without an identified cause. Most of our heat exchangers are used for heat exchange with oil, but the oil content in them is very low, and there are no oil droplets on the water surface.
In refineries, heat exchangers are primarily used for heat exchange with oil; water samples at the inlet and outlet of each heat exchanger were checked, and no abnormalities were found. .
There has been a leak; the emulsification of oil turns the water milky white, so no oil bubbles are visible on the surface.
Check out the acid gas treatment (desulfurization) units and the aromatic extraction units; these two types of units use media other than oils for heat exchange, namely alcohol amines and extraction solvents, and both of these media are soluble in water.