Four Practical Operation Skills of Swimming Pool Sand Filter
If the swimming pool pump is the heart of the swimming pool water treatment system, providing a steady stream of power, then the swimming pool sand filter is the lung of the swimming pool water treatment system, filtering impurities and returning water to clean! According to FENLIN17's 17-year working experience, some experience in the selection and use of swimming pool sand filter is sorted out and shared with friends in need.
( FENLINC Swimming Pool sand filter factory↑)
1. Selection of sand filter in swimming pools
We often meet customers' inquiries. What size of sand filter should I choose for my swimming pool? Generally speaking, the size and quantity of sand filter used in swimming pools are determined by the swimming pool size and cycle time.
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 sand tanks with a diameter of 1400 can be selected for filtration (unit: mm).
(FENLIN side mount of 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 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.
2. Sand cylinder head and multifunctional valve
All along, the usage of the functions of the sand cylinder head and the six-position valve is also one of the hot consultation questions. How to install several interfaces on the sand cylinder head? There is a simple and easy-to-understand slogan: upper and lower side drainage. The meaning is straightforward. The diagram shows:
Functions and operation methods of six positions of sand cylinder multi-way valve:
1. FILTER: press the handle on the cylinder head controller and push it to (FILTER) for normal filtration, then start the water pump to filter normally.
2. BACKWASH: the sand in the Pool sand filter constitutes thousands of water passages, and various impurities are filtered and left in the Pool sand filter, and the water passages gradually decrease with the increasing of impurities. That's why the pressure will reach over 30 kpa. Under this pressure, the Pool sand filter can't play any filtering role, so it must be cleaned according to the following steps: turn off the water pump, open the multi-way valve to the "backwashing" position, and open the bottom drain and loop valves. Start the water pump for about 3 minutes. When the operation is completed, the agglomerated impurities will be removed.
3. RECIRCULATE: at this position, multiple valves control the water flow from the pump to the pool water directly, without making the water flow through the inside of the Pool sand filter.
4. WASTE : If the pool water needs to be drained, you can use the filtered water pump. For this reason, put a number of valves in the WAST blowdown position. When the motor is running, fully open the drain valve to make the water pump fully absorb water.
5. RINSE: After BACKWASH the FILTER, if the multiple valves are put back to the normal filtering position of the filter, the water flow will be turbid for several seconds. Therefore, to prevent muddy water from entering the pool, the multiple valves should be put in the RINSE position.
6. CLOSED: This position is used to close the water flow from the filter to the water pump, and is used when the water pump hair collector is turned on.
3. How often do you backwash?
There is no formula for the backwashing cycle of swimming pool sand filter. Just like eating, you can eat as long as you are hungry. Besides, the swimming pool sand filter is widely used in different industries, and the backwashing cycle is different with different factors such as the amount of impurities. The following factors affecting the backwashing cycle are analyzed:
1) Different places of application. For example, some customers use sand filter to filter impurities in mountain spring water. In this case, mountain spring water is generally clear, so it is also possible to backwash once every ten days and a half months. However, some customers are used to filter impurities in urban sewage, which may be backwashed once a day.
2) Different selection of swimming pool sand filter. The flow rate of filter sand tank will vary with the pump flow rate, sand thickness, sand size, filter area and other factors. With the same suspended matter content and the same flow rate, theoretically speaking, the bigger the sand filter, the larger the filtration area and the smaller the resistance of water flow. The higher the filtering accuracy. The shorter the period of backwashing.
3) Customers' subjective judgments are different. Because some customers have subjective differences in the judgment of sewage after backwashing. Therefore, the backwashing cycle varies with his judgment.
Solution: A cycle can be determined according to the turbidity of the previous backwashing sewage and the reading of the pressure gauge. For example, during normal filtration, the count of the pressure gauge is 0.1MPa. When the reading of the pressure gauge reaches 0.2MPa, we backwash it once and find that the discharged sewage is not so dirty. Then we know that the next backwashing time can be extended. Repeatedly, every time we recorded this time interval. An optimal backwashing cycle will be obtained.
(FENLIN Top mount pool sand filter↑)
4. When does the 4.swimming pool sand filter need to be changed?
The quartz sand of fiberglass swimming pool sand filter should be replaced once every 1-2 years for the following reasons:
1) When backwashing, the filter layer will swell up by 1.2 to 1.3 times of volume, and the upward water flow will drive the filter layer to flow up and down, causing the filter particles to collide with each other. Because the materials are the same, the hardness is the same, and therefore, some of the filter materials will break into tiny particles, which will be lost with backwashing water;
2) Some quartz sand will be fused when the acid-base changes because of its insufficient purity;
3) After long-term use, the inside of the filter layer will be partially surrounded by colloid due to uneven distribution of water flow, and it will lose its function; Therefore, the longer the time goes by, the worse the filtration effect of the swimming pool sand filter will be. As backwashing will consume and take away some sand, we need to replace the sand in the sand tank within the specified time limit.
How to choose a good factory price swimming pool sand filter Fenlin swimming pool sand filter manufacturer, teaches you how to buy pool sand filter. If you want to know more about sand filter, please feel free to contact us!