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Floating rate of cooling tower

Author： Views: Time:2025-09-17

　　The floating rate should be calculated according to Appendix F of "Mechanical Ventilation Cooling Towers Part 1: Small and Medium sized Open Cooling Towers" (GB/T 7190.1-2018). Drift rate: the ratio of the amount of water that floats out of the cooling tower outlet to the amount of water that enters the tower per unit time.

　　measuring point arrangement

　　According to the diameter of the air outlet, divide the top of the cooling tower air outlet into 3-5 equal area rings, with 2 symmetrically arranged in each ring.

　　Experimental steps and calculations

　　After drying the filter paper, place it in a plastic bag, weigh it with a balance, take out the filter paper, and use auxiliary facilities to horizontally place the filter paper at each measuring point, and record the time. Leave it for 1-5 minutes depending on the floating water situation, quickly remove it, and time it. Put it in the original plastic bag and weigh it with a balance. Obtain the difference between two consecutive weighings, accurate to 0.01 g. Calculate the total amount of floating water Q based on the total increment, total area, outlet area, and placement time of the filter paper, and compare it with the inflow water flow rate. Calculate the buoyancy rate. Calculate by the following equation:

　　The floating water in the cooling tower is mainly caused by the following reasons:

　　1. Excessive wind speed

　　The fan speed is too high or the designed air volume is too large, causing the airflow to carry water droplets and overflow.

　　When the natural wind is strong (especially in open cooling towers), it exacerbates the dispersion of water droplets.

　　2. Packing problem

　　Blockage, aging, or uneven distribution of fillers prevent the water flow from being evenly dispersed, resulting in large water droplets that are easily blown away by the wind.

　　3. Defects in the sprinkler system

　　The nozzle is blocked, the angle is improper, or the pressure is too high, causing water droplets to splash.

　　Uneven distribution of spray, excessive water flow in local areas

　　4. Unreasonable setting of inlet water temperature for equipment

　　The inlet water temperature of the cooling tower is too high, resulting in a large temperature difference between the inside and outside of the tower. When humid and hot air encounters cold air outside the tower, it condenses into mist or small water droplets.

　　5. The device is not equipped with anti floating water measures

　　The cooling tower has not taken anti floating measures, such as V-shaped water collectors or water blocking plates.

　　solution

　　The methods to reduce the floating rate of cooling towers are as follows:

　　1. Optimize wind speed and airflow

　　Adjust the fan speed or replace the variable frequency fan to control the air volume.

　　2. Regular maintenance of equipment packing

　　Regularly clean or replace the packing to ensure even distribution of water flow.

　　3. Spray system adjustment

　　Clean or replace the nozzle, adjust the spray angle and pressure.

　　4. Properly cover the air outlet.

　　5. Equipped with anti floating devices.