As we all know, the pool sand filter is indispensable equipment for swimming pool water treatment. The main function of the pool sand filter is to physically treat the pool water, filter the pollutants, floats, and gel flocculants in the pool water through the filter layer filter material, so that the filtered water can be returned to the heating and disinfection process, so as to realize the recycling of water and achieve the purpose of environmental protection, savings and safety. According to the different needs of users, pool sand filter manufacturers have developed different types of sand filter cartridges, such as commercial sand filter cartridges, jet sand filter cartridges, side sand filter cartridges, horizontal sand filter cartridges, etc.
Precautions for using a pool sand filter
- Do not exceed the maximum pressure load of the sand filter cartridge during operation.
- When the working pressure exceeds the specified value for a long time, it will cause the filter sand cylinder, valve cover, valves, and other pipe fittings to burst, resulting in serious accidents, if the circulation system need to withstand high pressure, you need to install automatic valves or pressure regulating valves in the circulation system, so that the minimum working pressure of each component of the circulation system can automatically release pressure.
- When the sand filter is running, do not twist the screws on the head of the sand filter. The sand filter cartridge will move under high pressure during operation.
- When a certain part of it (joint, pump, sand filter cylinder, valve, etc.) is opened and needs to be repaired, air will enter the system, change the atmospheric pressure, compress the gas and cause the shell or valve to explode, causing casualties or property damage and other serious consequences, so do not tighten the screws on the head of the sand filter cylinder during operation.
- The water temperature flowing through the filter should not be higher than 45°C(plastic pool sand filter, inner tank) or 50°C(glass fiber pool sand filter).
- Be sure to stop pump operation before switching valve’s position
- Clean the pump filter screen and water distributor regularly to avoid pump damage or filter system failure
- The sand filter should run continuously at a medium filtration rate, for example,at low swimming load and at night, it should run at 50% or 35% filtration rate
- If the filtration rate needs to be increased, it should be increased slowly.
Daily maintenance of pool sand filter
- The pressure gauge connection pipe and the observation window should be cleaned once a month, and the working condition of the exhaust valve should be checked.
- Gauge and flowmeter readings should be checked for accuracy every three months and corrected.
- A manhole should be opened once a year to check the corrosion of the filter medium and the contact surface of the filter and the quality of the sand layer, and a new filter material should be added at the design height.
- With the increase of normal filtration time, the filter cake will gradually become thicker, and the filtration resistance will gradually increase. This is evident when the pressure increases to 30% above the normal pressure, as indicated by the pressure gauge reading (for example, from a normal pressure of 1.0 kg/cm2 to 1.3 kg/cm2).
Pool sand filter daily cleaning precautions
Pool sand filter cleaning method
It is necessary to clean the filter. Push the handle on the cylinder head controller back to wash, and the water will enter the filter header and drain through the filter pipe at the bottom of the cylinder block. The water will rise from the bottom to remove the dirt from the sand layer, and then push the controller into the cleaning tube to remove the dirt from the sand cylinder. After about half to 1 minute, press the handle to resume normal filtering. (Note: When changing the valve or cylinder head control position, the pump power should be turned off first)
Conditions requiring immediate backwashing of pool sand filter
- If, after the last backwash, the pressure gauge on the filter sand cylinder reads more than 50kPa higher than the initial reading, it needs to be backwashed immediately.
- The continuous running time reaches 5 days.
- Backwash is required if the pool is scheduled to be closed for more than five days.
Precautions for backwashing of pool sand filter
- The backwash time is generally chosen after the end of the swim every day and cannot be carried out during the swim.
- When there are multiple filters in the pool, it should be carried out one by one, and it is not allowed to backwash 2 or more sets at the same time.
- Backwash must control the backwash speed and time, backwash time 5~6 minutes or observe the backwash water until there is no suspended matter.
- If, during backwashing, the system pressure cannot be effectively reduced, this indicates that the quartz sand has compacted. Open the sand cylinder, mechanically stir the filter layer, and soak in a weakly alkaline sodium (sodium carbonate) saturated solution for 4 hours. Then proceed with sewage discharge and backwashing. If the effect is still not satisfactory, the filter needs to be replaced.
- In the process of replacing quartz sand, care should be taken to protect the filter tube to prevent damage and sand leakage. After replacing the quartz sand, the subsequent operations are the same as those for a newly installed sand cylinder. If the device is not used for a long time, leave the filter sand tank empty.