(PLEASANT EXPERIENCE OF INVENTION)
Once we received a request from a local paint manufacturer for a cooling tower. The client could not afford it, and was in a dead-end situation: no cooling tower - overheated equipment - poor quality of product - no income.
As we drank piping hot tea discussing his and other problems, we noticed that by pouring tea from one cup to another we accelerate the process of water cooling. And if we pour tea through a tea strainer, it cools down even quicker. The task appeared to be very simple: if we disperse water, then when falling down, it will carry along the surrounding cold air. And if air resistance is minimum, then the amount of sucked air will be no less then from a fan.
We made all the necessary calculations, and could not believe the results: with an innovative configuration of the spray nozzle we could achieve a very high surface-to-volume factor (up to 33,000 m2 of mass-exchange surface per 1 m3 of water) under a very little water pressure on spray nozzles (0,15 MPa)!
In one week we constructed a cooler at the paint manufacturer using only steel sheets and pipes, and made some measurements. One cubic meter of water can suck 1500 to 8000 m3 of air. The temperature of cooled water was 10% lower then at the traditional cooling tower due to the increase in the ambient air humidity to 100%.
The initial temperature of feed water can be up to 80C and brought down to a certain desired point. The height of a water cooler ranges from 4 to 9 meters.
Later we developed a tested methodology for the design and application of ejector-type water coolers.
That water cooler was not a big earner, but a pleasant experience of invention.
The same principle can be used in heating water with outgoing warm gases, regulated air humidification and other applications.