In order to estimate how large the pressure drop (pressure loss) will flow through the air through a filter consisting of more or less regular particles, I created the following program (in Excel).
![](https://www.lukaskolik.cz/wp-content/uploads/2019/05/Tlaková-ztráta-na-filtru-rozhraní-Kozeny-Carman-rce_new.jpg)
Graphical interface of calculator with used Kozeny-Carman equation
The version shown is based on the Kozeny-Carman equation, which is:
![](https://www.lukaskolik.cz/wp-content/uploads/2019/05/Tlaková-ztráta-na-filtru-Kozeny-Carman-rovnice_EN.jpg)
This equation is particularly suitable for low flow velocities where turbulence does not occur. At higher speeds, the flow becomes turbulent and such turbulence is energy intensive. The energy loss is then reflected in an increase in the difference between the inlet and outlet pressures (pressure drop), where the outlet pressure is lower and the speed also. In practice, however, the transition velocities between linear and turbulent flow are usually so low (0.1 m / s) that this equation is no longer satisfactory and more accurate is needed. The equation is several, I have chosen Ergun for this purpose and implemented it in the calculation.
![](https://www.lukaskolik.cz/wp-content/uploads/2019/05/Tlaková-ztráta-na-filtru-Ergunova-rce_EN.jpg)
The graphical interface preview of the newly created calculator is below.
![](https://www.lukaskolik.cz/wp-content/uploads/2019/05/Tlaková-ztráta-na-filtru-rozhraní-Ergunova-rce_new.jpg)
If you are interested in this kind of calculators, please contact me for your own project and we will come up with something. I will answer.
Kind regards
Lukáš Kolík, author
18.4.2019
Note: This article was not corrected. Original version was written in Czech. This is still artifically transleted.