Flocculator Tank Maintenance

Cleaning Tank

The flocculator needs to be cleaned as regularly as flocs start to build up in the tank otherwise they will affect turbidity measurements at the end of the tank. It should be obvious from looking at the last unused section of the flocculator that the tank needs cleaning. Flocs will have filled the the entire section. A pump and hose for cleaning the tank are next to the flocculator. Waste from the tank must be drained down the sink located in the far left corner of the plant (across from the tank). Waste cannot go into the grit chamber because the sludge contains aluminum compounds. Care should be taken when cleaning the tank- the sink clogs easily and floods the surrounding area. If the sink floods, the wet-vac is the easiest way to clean up the mess. When cleaning is finished, water can be emptied from the hose by detaching it from the pump and elevating the end. Walking the length of the hose while elevating it should empty the entire hose.

Running Tank

The pump for the tank can be plugged in on the far side of the plant above the rapid mix.

If pump is not working or there is very low flow:
The level in the plant grit chamber rises and falls. Sometimes air gets caught in the pump line and blocks the flow. The air can be released by loosening the threads in the line located by the rapid mix.

The alum pump is controlled by process controller. Each semester should create a folder with records of process controller method files and data.

Tube Settlers

Tube settlers should be rested at a 60 degree angle on the baffle connections and against the side wall of the tank. When they are connected the sampling line they should be submerged to fill them with water. If they are not submerged, the tube settlers will fill very slowly. The seal between the tube settler and the turbidimeter must be air tight otherwise the turbidimeters will not fill. Check to be sure the sampling line is all the way in the bulkhead fitting if the tube settlers are not filling.

Turbidimeters

Turbidmeters should be checked before any test is run in the flocculator. If they are dirty they should be cleaned with distilled water and kim wipes. If the turbidimeter reads dessicant, the dessicant needs to be changed. This can be done by unscrewing the lid of the turbidimeter and replacing it.

Sampling line

The sampling lines from the tube settler to the tank are easily clogged. Back washing them should solve this problem. Some times clogs form the inlet valve for the raw water sampling line. Toggling the valve to increase and decrease pressure in the line should solve this problem.