Selection of Swimming Pool Sand Filter and Matters Needing Attention in Use
Selection of Sand Fliter
Regardless of the material, generally speaking, the size and quantity of durable swimming pool sand filter used in swimming pools are determined by the size of swimming pools. The specific calculation method is:
Pool water capacity V= length x width x average depth
Circulation flow Q= pool water capacity X1.05÷ circulation period 4h
Note: The swimming pool cycle is 4 hours.
For example, if a swimming pool is 25m in length, 16m in width and 1.4m in average depth, the water volume of the pool is 25mX16mX1.4m=560m³, and the circulating flow is 560m³X1.05÷4h=147m³/h = 147m/h if it is filtered once every 4 hours.
The circulating flow rate of the swimming pool is 147m/h, so according to the medium-speed filtration (25m/h), according to the actual demand, four swimming pool sand filter with a diameter of 1400 can be selected for filtration (unit: mm).
（FENLIN Top-mount Pool Sand Filter↑）
Note: The filtration rate is the amount of water filtered in unit time per unit filtration area. In order to standardize the filtering speed of the circular swimming pool sand filter and facilitate the design and selection, when the filtering speed v≤10m/h, it is called low-speed filtering; When the filtration rate is 11-30m/h, it is called medium-speed filtration; When the filtration rate is 31-50m/h, it is called high-speed filtration.
Practice has proved that the filtration rate is within the range of 10-25m/h, and the filtration effect and pressure loss of the filter are directly proportional to the filtration rate. If the filtration speed exceeds 25m/h, the filtration efficiency will decrease rapidly, that is, with the increase of filtration speed, the quality of filtered effluent will deteriorate continuously. Therefore, in order to ensure that the filtered water quality meets the requirements of hygiene, health and clarity, the filtration rate of public swimming pools should be ≤ 25m/h.
（FENLIN Side-mount Pool Sand Filter↑）
The Matters Meeding Attention In The Use of Sand Fliter
1. Check before startup.
① Before starting, the multi-way valve of the swimming pool sand filter should be adjusted to the filtering state;
② Check whether the corresponding valves on the pipeline are in the correct state;
③ Check whether the hair collector is blocked, and if so, clean it up first; Check whether there is air in it, and if there is, exhaust the air first;
④ Check whether the commercial swimming pool sand filter cover is tight and airtight. If it leaks, tighten the tank cover to make it tight and airtight; Check whether the liquid medicine pipe of each dosing system is normal and free of blockage, whether there is liquid medicine in the medicine barrel, and whether the valve of the dosing device has been opened to ensure that the dosing system is in a ready state;
⑤ Check whether there is air accumulated in the main backwater pipeline, if so, it must be eliminated by the drain valve;
2. Boot sequence
① Turn on 1 pump motor first; After the water pump motor runs normally, turn on the water pump in turn, and the standby pump does not need to be turned on;
② Record the pressure gauge index on the filter and check whether backwashing is required; Check the operation of the water pump, whether it runs smoothly and without noise; Check whether each dosing system is running normally; Go to the pool and visually check whether the water from each water injection port is normal.
（Swimming Pool Sand Filter FENLIN Factory Real Scene↑）
Steps and Precautions for Changing Sand
1. Sand changing step of swimming pool sand filter:
(1) Quartz sand selection: the sand used in the filter sand tank is quartz sand, which is a regular hexahedron with eight corners.
⑵ Open the swimming pool sand filter and clean up the original sand and dirt.
(3) Stacking of quartz sand: During stacking of quartz sand in sand tanks, there will be gaps between the edges and corners of each quartz sand. These gaps can make water pass through smoothly, but impurities larger than the gaps can't pass through, which can play a purifying role.
However, the size of the gap determines the filtration accuracy of the swimming pool sand filter. When the gap is small, the filtration accuracy is high. However, if the gap is too small, the water output of the whole sand layer will be reduced, thus affecting the water output of the swimming pool sand filter.
Therefore, the gap between quartz sands determines the filtration effect, and the size and integrity of quartz sands directly determine the gap size of quartz sands. Therefore, it can be known that the size of quartz sand and the integrity of quartz sand are crucial factors for sand tank filtration.
(4) After the quartz sand is paved, install the swimming pool sand filter, and check the tightness.
（FENLIN's Swimming Pool Sand Filter Case Project↑）
2. Matters needing attention in sand replacement of filter sand cylinder:
(1) Before changing the sand, completely cover the original water pump with impervious materials such as plastic to prevent water from entering the pump and causing the pump to burn out.
⑵ When filling quartz sand, the central pipe should be sealed with raw tape to prevent quartz sand from entering the middle pipe.
⑵ When cleaning quartz sand, be sure to wash it first and then backwash it. Pay attention to the pressure gauge during backwashing. If the pressure exceeds 3kg during backwashing, you should immediately hit the front washing.
(4) The filling volume of quartz sand should not exceed 70% of the total volume, so as to have backwashing space.
（5） Generally, the original water pump should be turned on for cleaning, and the pressure of tap water is not enough to clean it, unless the pressure of raw water is very high.
（Swimming Pool Sand Filter Should Be Placed On A Flat Ground↑）
Equipment From The Flatness of The Ground
When the swimming pool sand filter is filled with sand, the overall weight is very large, so the ground on which the sand cylinder is placed is required to keep a certain levelness. Because the base of the pool sand filter is designed on a very flat ground, if the ground in the equipment room is uneven after installation, the filter sand base will be deformed.
Anti-freezing In Winter
When the swimming pool sand filter is not used in winter, all the water in it should be drained through the lower sewage drain valve. To prevent the water from freezing and expanding in the cylinder body and bursting the multiple models swimming pool sand filter body.
