Precautions for Operating Quartz Sand Filter

The main factors that affect the operation of sand filters include filtration rate, backwashing and water flow uniformity.

(1) The filtration speed of the sand filter cannot be too slow. Because the filtration speed is too slow, the amount of water processed per unit filter area is small. In order to achieve a certain amount of water output, it is necessary to increase the filtering area and increase investment. However, if the filtration speed is too fast, it will not only increase the head loss, but also shorten the filtration cycle and reduce the quality of the effluent. The filtration speed is generally 10-12m/h.

(2) Backwashing is used to remove mud in the filter layer to restore the filtering capacity of the filter material. In order to wash away the mud, a certain backwash speed and time are necessary. This is related to the size and relative density of the filter material, expansion rate and water temperature. The backwash intensity of quartz sand used as filter material is 15L/(m2·s). During backwashing, the expansion rate of the filter layer is 25%-50%, and the backwashing time is 5-6 minutes. Only when the backwashing effect is good can the sand filter operate well.

(3) Uniformity of water flow, whether during operation or backwashing, the water flow in each section is required to be evenly distributed. To make the water flow even, the main thing is that the drainage system must be good. Only the uniformity of water flow can achieve good filtration effect.

Sand Carbon Replacement Steps

1). Tools required for replacing sand carbon: pipe wrench, sand suction pipe, raw tape.

2). Before replacing the sand carbon, conduct a comprehensive inspection of the filter to see if there are any broken parts in the customer's filter. If so, explain to the customer in time and record each operating parameter, especially quartz sand. , the water inlet pressure of activated carbon.

3). To shut down the equipment, first of all, if there is reverse osmosis, you must first stop the reverse osmosis host pump, then stop the original water pump, and then close the water inlet of the original water pump.

4). To disassemble the equipment, for larger sand carbon canisters such as the 2472 canister, you can use a pipe wrench to open the core filler. For smaller equipment, such as the 1354 canister, you can directly lift it open by hand. Use a sand suction can to suck out the sand carbon in the tank. The sand carbon suction uses the siphon phenomenon. Be careful to exhaust the air in the suction pipe.

5) . When replacing sand carbon, it is generally necessary to replace the carbon first and then the sand, because the newly installed activated carbon must first be soaked in water to make it fully moist and eliminate the air between and inside the carbon particles so that the carbon particles do not float. On the water, it is also to save time. First put a small amount of water at the bottom of the carbon canister, and then fill it with activated carbon.

6). The filling volume of activated carbon is about 70% of the total volume of the carbon canister. In order to leave enough backwash space. After loading the carbon, pour water into the carbon can so that the water can completely soak the activated carbon.

7). Before changing the sand, a small amount of water should also be injected into the sand tank. The quartz sand should be filled in the order of large sand at the bottom and small sand at the top. The filling volume of sand is about 70% of the sand tank.

8). After filling the sand, reinstall the equipment. Washable quartz sand, before washing, make sure the valves are opened correctly, that is, the water inlet valve and the upper discharge valve, and close the activated carbon water inlet valve. Then turn on the original water pump, wash forward first, and then backwash. Then forward and backwash are performed alternately. Wait until the water coming out of the waste water valve is clear.

9). Confirm that the quartz sand has been washed clean, start the original water pump to clean the activated carbon, first wash forward and then backwash until the water is transparent, colorless and free of fine particles before it can be put into use. Turn off the water supply to the softener when cleaning activated carbon.