Why Is Sand Washing Aggregate Needed

The sand washing aggregate belongs to different operation purposes. The cleaning is an action performed when the backwashing efficiency is reduced. The backwashing is to remove the contaminants captured in the filter and make the filter The function can continue to operate, as detailed below.

1. Backwash operation

The efficiency of the filter is mainly judged based on the decrease of the circulation pipeline flow rate per unit of time. In practice, the pressure rise of the filter is used to judge the efficiency of the filter, which is the so-called pressure difference or head loss. This is because, in the circulating filtration of pool water, pollutant particles are accumulated and collected in the filter layer of quartz sand, which causes the surface of the quartz sand particles to thicken, which hinders the flow of water and increases the pressure of the filter. With the help of backwashing to eliminate accumulated pollutants, reduce the pressure of the filter, and increase the filtration flow; the main consideration is because the filtration system of the swimming pool is a cyclic filtration type, which not only takes care of the conditions of filtration efficiency, It is also necessary to consider the ability to promote water circulation. Therefore, the control of head loss is generally recommended to be maintained at about 0.5kg/cm　, that is to say, beyond this pressure difference range, although the filtered water quality is better, the filtered water will be reduced. , The thrust is also insufficient, so that the circulation efficiency is not good, and it is easy to have dead spots. In addition to the continuous pollution of swimmers, the water quality of the pool will not be improved due to the filtration at this time, but will get worse and worse; In the differential pressure range, although the number of water cycles increases and the thrust is sufficient, the filtered water quality is not very satisfactory. Moreover, the frequency of backwashing is too frequent, which will cause a waste of water resources; therefore, from the filtration pressure (initial pressure) after backwashing, plus 0.5kg/cm2　 (pressure difference) is the pressure for backwashing (final pressure) ), that is, the initial pressure plus 0.5kg/cm2 is the pressure to be back washed.

2. Cleaning the quartz sand filter

The reason is the accumulation of grease rather than the calcification of the sand layer. Because the water in the swimming pool or massage pool contains a lot of suspended human lipids, these fatty substances will accumulate on the surface of the quartz sand particles if they are not properly impacted, making the quartz sand affect the fat Re-exclusion, and then the fat will continue to penetrate into the depth of the filter layer, and eventually occupy the entire filter layer. At this time, the fat will be completely unable to be captured by the filter due to the rejection of the overall filter layer. There is white, green, or even yellowish turbidity, even backwashing can not improve the water quality, so we have to change the water or replace the filter material to solve the problem. But it didn’t take long for this situation to recur, and this kind of situation is especially easy to find in high-temperature pools. The commercially available filter cleaner is a medicine used in this situation, and it is used to clean the organic lipids attached to the surface of the filter material. When the following situations occur, it is time to clean the filter:

1) The number of backwashing of the filter is frequent, and the effective operation period becomes shorter.

2) The initial pressure of the filter cannot be reduced after routine backwashing.