Technical
EVAPORATIVE COOLING AND
HUMIDIFICATION SPRAY NOZZLES
By Monitor Distributors T / A Hawk Pumps
Anyone who uses high-pressure pumping equipment for professional purposes knows that every nozzle is different .
For those in the know who would like to know even more , in this article experts highlight some of the benefits of evaporative cooling and humidification spray nozzles .
There are many applications where micro-fine water droplets are required . Generally , micro-fine droplets come into play for applications that need any water spray to evaporate before wetting the surroundings . This method serves two purposes – evaporative cooling and humidification .
EVAPORATIVE COOLING When water evaporates , energy in the air ( heat ) dissolves the droplets , effectively removing some of the heat and resulting in cooling of the air . It ’ s a bit like when a dog or a chicken pants when it is hot and the air flow evaporates their saliva , counteractively cooling the animal internally .
A typical example of the effect of cooling by evaporation is where a restaurant has rows of nozzles on pipes with a highpressure pump forcing water through extremely fine jets . The droplets are so small that the water evaporates completely before reaching the customers , but the air temperature drops significantly , cooling the customers down as they walk through the spray .
The same principle is used in chicken runs as another example . In some areas , the high air temperature can kill the birds and evaporative cooling saves them .
All images : Hawk Pumps
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HUMIDIFICATION Water evaporation will obviously increase the amount of water dissolved in the air ( humidity ), and there are many examples where an increase in humidity , is an asset .
Experiments have been conducted where increases in the humidity surrounding day-old chicks effectively improved the ratio of food consumption to weight gain of adult chickens , allowing the slaughter weight to be reached earlier .
Timber drying sheds at sawmills require careful humidity control to stop logs cracking .
Textile weaving sheds need humidity to avoid static electricity build-up , which causes threads to snap .
1 and 2 : Humidification nozzles used in a warehouse storing polystyrene . This was done to keep static electricity under control , reducing the risk of fires .
An example of connectors with an MPT nozzle used in an evaporative cooling system .
www . hvacronline . co . za RACA Journal I March 2022 57