OUBER Engineering Conversion

The table of OUBER evaporative air cooler' s air change rate (suggest)

OUBER Engineering conversion

Air inlet volume = intake air volume cross-sectional area * average wind speed * time

Air outlet volume = outlet air volume cross-sectional area * average wind speed * time

Air volume: m2/h; Cross-sectional area: m2; Wind speed: m/s; Time: h (3600s).

Characteristic of OUBER Centrifugal Fan

The centrifugal fan must be operated with the rated current, otherwise the motor will be destroyed, if the current is over the rated current. The centrifugal fan adjusts the current of the fan motor by adjusting the outlet cross section. When the fan is maximum outlet, it cannot be run over the rated current, or the motor will also be destroyed. Therefore, there must be enough resistance at the outlet to make sure the fan motor is operated at the rated current. For any conditions, it cannot not be run under the condition of the outlet fully open.

The centrifugal duct is 45m, and the air supply efficiency is about 90%. The section of duct should be the same as the outlet, and when air supply in both directions, it should be careful that the possible problem of current exceeds the rated caused by overlay of the duct section.

Characteristic of OUBER Axial Fan

It is the best for operating axial fan under situations of max air outlet area and min air outlet resistance. The smaller the duct section or the more the bend, the greater the air resistance. The greater loss on air volume, the less actual air outlet. Under any circumstances, it should keep running in the form of max air outlet area and air intake area with min air resistance.

High tension axial fan has high wind pressure, large air volume, stable air outlet and big noise in operation. It is suitable for installation project with long distance duct, and the occasion of big environmental noise. The air supply efficiency is about 50%, if the air supply length of the straight pipe is about 30m. Long duct should have a reducer in every 10m to piecewise reduce cross section for keeping wind pressure. Short straight duct has a big cross-sectional area, and high air supply efficiency, however, long curved duct has a small cross-sectional area, and low air supply efficiency. Low tension axial fan has low wind pressure, large air volume, stable air outlet and smaller noise in operation compared to high tension axial fan. There will be a great loss, when using duct for air supply. It leads to few actual air outlet, and it is not suitable for long duct air supply mode.

For the occasion of high standards of noise, generally a muffler with centre line of more than 1.5m will be matched. The actual wind section of the muffler≥the main duct section, and it will not form the air supply barrier. The use of the muffler may reduce the actual air outlet volume.

Calculation of position cooling diffuser quantity

The main machine is the high tension, axial and air volume of 18000m3/h. Using long duct for air supply, and the distance between the duct and the ground is 2.2m. The length of duct is 30m (First part: 800mm X 500mm; Second part: 700mm X 500mm; Third part: 600mm X 500 mm). The wind speed of diffuser air outlet cross section is 0.039m2. Calculate how many position cooling diffuser can be set up with conditions above.

Calculation method:

Actual Air Volume/Time/Outlet Wind Speed = Outlet Area/Single Outlet Area = Quantity of Position Cooling Diffuser

18000 m/h X 50% = 9000 m/h /36000s/4 m/s= 0.625m2/0.0396m2= 15 pcs

The whole cooling space and equipment quantity

Target Cooling Range (area X height) X Air Exchange Rate (time/h)/ Single Machine Air volume : (intake), if the factory is higher than 5m, still calculate at 5m. Assume that the area of the smelly factory is 5000 m2, and its height is 7m. Check out Ventilation Cooling Air Exchange Frequency Table, air exchange and cooling at 50 times/h. The exhaust air rate of single negative pressure horn exhaust fan is 46,000 m3/h, as 60% of total supply air rate. Calculate separately using evaporation air cooler Model 18 and Model 46, and negative pressure horn exhaust fan Model 46. Measure the quantity for installation, according to different conditions provided above. Calculation method:

5000X 5= 25000X 50= 1250000/18000= 69 set; exhaust fan: 1250000 X 0.6= 75000/46000= 16 set

5000X 5 = 25000X 50= 1250000/46000= 27 set; exhaust fan: 1250000 X0.6 = 75000/46000= 16 set