How to minimize pressure drop across filters to receive the maximum performance

The difference between inlet and outlet pressure is known as pressure drop or differential pressure. It cannot be recovered and caused by the filter, mainly due to frictional drag on the fibers of media. Differential drop may increase as the particulate rating or efficiency of the filter. Pressure drop increases with increasing in loading of the filter due to contaminant.

Various factors responsible for pressure drop

Filter media: Media is definitely, the major component influencing the pressure drop, certainly it causes pressure drop. Which is why due to low friction, high flowing media is essential. It is feasible to control the fiber size and distribution pattern throughout the media mat and still enable the smooth, nominally interrupted fluid flow.

Dirt contaminants

With catching dirt in the media, it eventually starts to accumulate and fill the mesh holes. With shrinking of openings, the differential pressure increases which is known as restriction. Too much dirt in the media can cause dirt migration or even filter damage. Dirt migration occurs when the restriction is high that the differential pressure pushes dirt deeper in the media and finally through the media and back into the system. Filter damage occurs when the restriction is increased too much that filter cartridge damages or bursts to relieve the upstream pressure. Inconel mesh for filter media offers the suitable performance by offering minimum pressure drop.

To prevent this damage, it is recommended to use a filter service indicator. It states the pressure throughout the filter, then signals when the filter is full and requires to be changed.

Flow

Higher flow causes higher pressure drop. With quickly running hydraulic  fluid, more friction causes higher pressure drop throughout the media.

Fluid viscosity

Fluid viscosity states the resistance to fluid to flow. With increase in fluid viscosity, higher pressure drop occurs as thicker oil has a tougher time flowing through the layer of media mesh. Cold fluid is a common example of high viscous fluid.

Filter media, magnitude of contamination, flow rate, fluid viscosity are factors which should be considered to size the filter for system requirements. Filters which are very small cannot handle the system flow rate and will create wide pressure drop from the beginning. The outcomes could be filter service in the bypass mode, filter failure, component malfunction, or extreme system failures. Filters which are very small cannot handle the system flow rate and will cause very high pressure drop from the beginning. Large size filters demand more system oil and higher cost replacement filters. Medium sizing is recommended.

The filter media function should be evaluated while removing particles. Fluid analysis and field monitoring are the best ways to get the correct measurements. To determine which media is best to protect your component,  contact Heanjia. Engineers need to make tough decisions about which filters they should choose that they can afford and which ones will offer the best service. So much depends on the cleanliness of the component, service conditions and duty cycle of the equipments and other factors.  You should get in touch of Heanjia to receive the best assistance.