How to calculate the volume of a water tank for cleaning
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The company has installed a water treatment system that uses reverse osmosis membrane units, with two stages: 22 membrane modules in the first stage and 15 membrane modules in the second stage. (8 inches) While cleaning the system, it was found that the capacity of the cleaning tank is too small. How can I calculate the capacity of the cleaning tank?
Without a membrane shell, it’s 34-55 liters, plus the volume of the pipes. By the way, how is your level 1 arranged?
The calculation of the volume of a cleaning tank should take into account the following two aspects: (1) The internal volume of the pressure vessel: V1=πd²L, where d is the radius of the vessel. Length of container L; total volume of the container V2 = V1 × N, where N is the number of pressure containers in the first section. (2) Pipe volume: V3 = πr²L, where r is the radius of the pipe and L is the length of the pipe. The total volume V = V2 + V3. The volume of the cleaning tank = the empty volume of the pressure vessel + the pipe volume + a margin
For the calculations above, the volume required for cleaning the security filter should also be added, which is generally around 0.3–0.5 m3； It is advisable to have a headroom of around 1 m3 (taking drainage into account at the beginning of cleaning). Additionally, in the case of segmented cleaning, the volume of pressure vessels generally only needs to take into account the number of segments; if there are no segments, then the total number of pressure vessels must be considered.
The water treatment unit is of two stages and two sections: the first stage and first section consist of 15 membrane housings, while the second stage and first section have 7 membrane housings; the first stage of the second stage has 10 membrane housings, and the second stage of it has 5 membrane housings. When calculating the volume of pressure vessels, should it be based on a single-stage membrane shell or a two-stage single-membrane shell?
Cleaning is carried out in stages; based on 17 membranes, each membrane requires at least 34 L of volume, and the volume of the pipes and filters is added to this amount. Finally, a coefficient of 1.3 to 1.5 is applied (taking into account the need for water in the tank for circulation)
Calculate the water volume based on the maximum operating conditions; the volume can then be determined using the density at that time
It seems unnecessary to add a security filter, as the chemical cleaning solution goes straight into the reverse osmosis system; generally, cleaning devices already come equipped with their own filters
If segmented cleaning is not performed, consider the volume of the 22 membrane shells anyway； If cleaning is done in segments, then only the cost of 15 shells needs to be calculated. The volume should be: the total volume of the membrane shell + the volume of the pipelines + the volume of the cleaning filter + the volume reserved for circulation. It is generally recommended to reserve 1 m3 as this amount. If cleaning is done in segments, and no new solution is prepared after cleaning one segment before moving on to the next, the amount to be retained must be increased further to prevent insufficient circulation volume after discharge.