Calculates the pressure drop or the dynamic pressure drop of
a channel part suction or blowing air (ventilation channel).
For circuits composed by different parts with different sections is necessary
calculate separately and sum the results of each part.
Data input
Pipe characteristic.
Selection of tube material
Notes on the material
Absolute roughness of the inner wall
mm
Inner diameter of the tube
Ø i (mm)
Gas velocity in the channel.
Required flow rate
m3/h
Normal values for civil and silent applications.. Conditioning public places, home and office, space heating in general, air recirculation system, fume exhaust.
Normal values for industrial applications. Heating or cooling system, circulating ovens at a low temperature, air recirculation system for environments, fume extraction and harmful gases.
Normal values for special applications. Suction shavings, pneumatic conveying of solids (eg plastic granules), pieces cooling after molding, power cyclones separators powders, implants for compressed air and other gases.
Gas characteristics.
Selection of the gas to be carried
Gas density
kg/m3
Circuit components.
Channel lenght
m
Angle deviation
n.
90 degrees curve (in 3 parts)
n.
Ratio R/D
R (mm)
90 degrees curve
n.
Ratio R/D
R (mm)
Results
Gas velocity in the pipe
m/s
Relative roughness on the inner wall
r/d
Reynolds number
Friction coefficient (Colebrook)
Result of dynamic pressure drop
mm H2O
Notes.
Curves with R/D ratio greater than the maximum available can be ignored
(add the development of the curve on the lenght of the pipe).
The gas velocity in the yellow zone are used for pneumatic transfer of various
chips or pellets, not usable for the suction or ventilation plants.
Increasing the curve radius decrease the pressure drop due to the change of
the direction of the gas, but increase the lenght of the tube with apparent greater
pressure drop, for a correct valuation insert the real lenght in the straight
pipe by substrating the part occupied by the curves.
Instructions
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Notices
The apps about pressure drop.
For air and other kind of gases, (round pipe).
For air and other kind of gases, (squared or rectangular channel).
For fluid at liquid state, (general hydraulic plants).