Register to reply

Relationship between differential pressure and airflow through a filter

Share this thread:
Apr12-12, 11:08 AM
P: 2
I have a question regarding the relationship between differential pressure across a filter, the airflow through the filter and the size of the orifice that the aire is moving through. I would like to be able to predict differential pressure required to maintain a constant airflow as the filter I am using blocks over time.

I am having trouble finding a suitable expression online and Filter Manufacturers do not supply this information with their filters.

Can anybody tell me if there is a simple expression which can be used please?

Thanks in advance to anybody who can assist me!

Phys.Org News Partner Physics news on
Refocusing research into high-temperature superconductors
Neutron tomography technique reveals phase fractions of crystalline materials in 3-dimensions
Tiny magnets, huge fields: Nanoscale ferromagnetic electrodes create chemical equivalent of solid-state spin valve
Apr12-12, 08:29 PM
P: 22,248
Welcome to PF!

I'm sorry, but this can't work because you have one unknown driving the other: You would have to know the loading of the filter to find the pressure drop on a table or via a formula but the only way to measure filter loading is by measuring the pressure drop!

What you need is to maintain a constant dp across a device known to be fixed, such as a cooling or heating coil. Then the pressure across the filter can fluctuate while keeping the airflow constant.
Apr13-12, 06:32 AM
P: 2
Thanks for the welcome Russ. I am not an engineer so I am taking time to get through things that probably seem very basic.

In relation to the pressure drop and loading I am working through correlating the two through measurements.

I am using a vacuum pump to generate the flow through the filter but cannot control the pressure or loading accross the filter. I know the pressure before and after the filter but not the airflow. Am I dealing with too many unknowns? Thanks for your help.


Register to reply

Related Discussions
Static pressure and airflow at reduced fan speeds Mechanical Engineering 0
Pressure and Volume relationship Chemistry 1
Air pressure/temperature relationship Classical Physics 1
Relationship between static pressure and CFM Mechanical Engineering 1
Airflow/Pressure relationship Mechanical Engineering 8