The circulating cement sand has a large volume and high turbidity; can a flocculant be added to cause it to settle?
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In our company’s 12,500/h circulating water system, the water becomes turbid during operation; the dirt and sediment accumulated in the heat exchangers are washed into the reservoir. When the filter is activated, it takes a long time for things to return to normal. Is it possible to use flocculants to cause these substances to settle, so that they can be removed during major maintenance?
I haven’t encountered this issue; it’s probably a water quality problem. You can add flocculants to cause sedimentation, and then clean it up during major maintenance. Give it a try
There is definitely an effect, but there are also risks. Can it be ensured that the accumulated dirt and sediment won’t be drawn out? In fact, attention should be paid during normal operation: the side filtration system should run continuously on a daily basis, rather than being used as a solution only when problems arise. If the normal operation of the side filtration system still does not meet the system’s requirements, it is because the designed flow rate for side filtration is too low (usually around 10% of the circulation volume) ； Or the side filtration isn’t effective.
You can add a flocculant for side filtration; give it a try.
Here are several reasons for turbid circulating water, for reference: 1. Turbid water added to the circulating water system; 2. Insufficient amount of backwash; 3. Inadequate control of microorganisms and algae. The causes can be identified from these aspects. During major maintenance of the system, it is necessary to thoroughly clean the sediment at the bottom of the reservoir.
Poor precipitation due to the use of flocculants leads to an increase in the turbidity of the circulating water, thereby increasing the likelihood of scaling and corrosion. The best approach is to divert the circulating water for flocculation sedimentation or air flotation treatment.
Floculants cannot be added; there is no place in the process for adding them, unless an additional sedimentation tank is installed (so far, floculants have not been used in the closed-loop system). If the turbidity of the raw water is above the acceptable level, flocculation can be employed. At present, the only option is to increase water replacement – by draining and refilling large amounts of water, as well as increasing the amount of water filtered through the side filters (which should always be in use). If bacteria are the cause of the problem, then disinfection efforts need to be intensified; after each disinfection session, when turbidity increases significantly, water replacement should be carried out. During maintenance, if possible, the tank should be cleaned. If there is no bottom discharge outlet, sludge pumps can be used to remove the sludge, followed by manual cleaning. After refilling the tank with water and starting the circulation again, if the water remains turbid, further replacement and enhanced drainage are necessary
It probably won’t work; adding a flocculant might even increase the turbidity, as the water keeps being stirred. Fresh water can be added for replacement, and the tank is cleaned during major system overhauls.