Water Quality Requirements for Misting System

The working principle of the high-pressure misting system is the industrial plunger water pump pressurizes the purified and filtered clean water to 70 bar/1000 psi, and transports it to the mist nozzle through high-pressure pipes, then the high-pressure water is sprayed out from the specially designed holes of the nozzles and atomized into mist droplets with a diameter of 5-20μm, are sprayed into the air. These spray particles can increase air humidity, eliminate static electricity, reduce dust, and lower temperature. In addition, adding disinfectant to the water tank also play the role of disinfection and deodorization.

The application of high-pressure misting systems in production is very common. Especially for the overall and local humidification of the space in industries such as textiles, tobacco, electronics, printing, and coating. It can also be to dust suppression in coal mines, steel plants, cement plants, mixing stations, and stone factories. It can also be used for landscape fogging in parks and scenic spots, vill, sales offices, etc. It can be used for cooling in train stations, bus stops, gas stations, and factory roofs. It can be used for deodorization andinfection in landfills, breeding farms, sewage plants, and chemical plants.

The high-pressure misting system has specific requirements for water quality. Filtering treatment is the key link to ensure the stable operation of the system. Moreover, in some spray places where people are present, human skin and respiratory tract will come into contact with and inhale these fine water mist, so the water quality must be strictly controlled.

Water Quality Requirements

Since the diameter of the mist nozzle is small, the misting system has strict requirements for water quality, otherwise, the nozzle is prone to blockage. The water must be filtered through a reverse osmosis system to pollutants such as salt, calcium, aluminum, magnesium, etc. These substances act as electrolytes and can cause serious corrosion of the nozzle.

Recommended Water Sources

  • Municipal tap water is preferred because it contains less impurities and the treatment cost is relatively controllable.
  • If using non-standard water sources such as river water, well water, or lake water, additional strengthening of filtration measures (such as adding a softening device) is required.

Hardness of Water Treatment

For high hardness water sources, it is necessary to configure a soft water treatment system to remove calcium and magnesium ions through ion exchange or reverse oosis technology, preventing scale from blocking the nozzle and corroding equipment.

Prohibited Use Excessive Impurities Water Source

Water sources containing a large amount of mud, rust, or microisms need to be strictly filtered, otherwise, it will accelerate equipment wear and reduce the uniformity of the spray.

Filter System Configuration The filter level needs to be flexibly adjusted according to the application scenario and water quality difference.

Normally, the system shall use water which meets the manufactures requirements. As a minimum the water shall meet the following requirements:

  • Equivalent of a potable water supply
  • Colorless and odorless
  • Non corrosive
  • Chloride concentration < 50ppm (=50mg/l)
  • pH value 7.0 – 9.0
  • Iron (Fe) and Manganese (mN); sum < 0.3mg/l
  • No free chlorine

Ordinary Small Places

Some small spray places, such as coffee shops, outdoor barbecue shops, villas etc., can use tap water for the misting systems after simple filtration, and the cost of this filtration device is low.

It is best to use three-stage filtration:

  • First-stage: filtration uses polyphosphate filters to soften hard water.
  • Second-stage: filtration uses 15 micron PP filter, filtering impurities above 15 microns.
  • Three-stage: filtering impurities above 5 microns.

Scenarios for High-Precision Filtration

For places with strict water quality requirements (such as landscape fogging, direct drinking spraying), it is necessary to add an RO reverse osmosis membrane and activated carbon behind it to make the water quality close to the standard for direct drinking.

The Necessity of Filter System

  • Anti-blocking: Multi-level filtration can intercept more than 99% of impurities, significantly reducing the probability of nozzleage
  • Extend the life of equipment: Red the wear and tear of high-pressure pumps and pipelines caused by scale and particulate matter, and reduce maintenance costs
  • Improve the effect of spraying: Pure water atomizes more evenly, which can enhance the efficiency of cooling and dust reduction

Maintenance Suggestions

Filter Element Replacement: Replace PP filter cotton every1-3 months (depending on water quality), and replace activated carbon and ultrafiltration membrane every 6-12 months. Even if the equipment is used infrequently it is necessary to replace it on time, because water that remains in the system for a long time will form scale and microorganisms.

For RELAB's fine mist nozzles, normally we use a 10-15 micron filter plug, such as FF, FE, FG and FJ series.