PTFE membrane, commonly known as “Teflon” has been widely used on cookware for the past 60 years because of its superior non-stick qualities. It’s also very useful when applied to outerwear, because it is waterproof and breathable at the same time. When viewed up close under a microscope, PTFE material is covered in tiny microscopic holes that looks similar to swiss cheese. These tiny holes allow vapors and gases such as air, water vapor to cross through the material easily while stopping denser materials including liquids, and dust particles from crossing through, making it the perfect filter material to use in dust collector applications.
How PTFE Membrane Works:
On a normal filter bag, dust begins to collect on the surface of the bag and creates a build-up of dust called a filter cake. In the cake, the particles come together and create a fairly good efficiency, typically about 99.97% or better. The filter acts only as the support for the cake and does not provide much filtration at all. When the bags are pulsed to clear the filter cake, some of the cake releases, but over time, the dust particulate embeds itself into the fabric causing failure or plugging of the system.
Conversely, when PTFE membrane is added to a bag it acts as the filter cake. The efficiency of the membrane is higher, exceeding 99.99% and can reach as high as 99.999%. The membrane allows for very little dust to stick to the bag so when the bags are pulsed, they clean very well. The dust stays on the surface and never gets embedded into the fibers of the bag.
This increases bag life but also allows the system as a whole to perform more efficiently. PTFE membrane bags don’t require pulsing as frequently as normal filter bags because the bags stay cleaner and the membrane itself reduces filter cake. Less pulsing means less wear and tear on the bags and on the system. Not only will the bags perform better longer, but the pulse valve solenoids and diaphragms won’t need to be replaced as often.
On-demand cleaning allows for the bags to clean only when the differential pressure gets to a high range as set by the operator and then pulse down to a lower range. The cleaning then pauses until the high range is again reached, thereby only cleaning when demanded. The cost of the cleaning timer and module required is insignificant compared to the savings in cost from bag wear, change-outs and plant down-time.
Benefits of Using PTFE Membrane and On-Demand Cleaning:
- Longer bag life (up to and exceeding 2 times normal life)
- Bag fibers do not become entrained with dust
- Bags require less pulsing, reducing wear on the bags.
- Labor savings on bag change outs (not required as often)
- Bags can withstand some moisture and still perform well
- System will rarely plug because bags do not become blinded
- Less compressed air consumption resulting in less energy consumption
- Pulse valve diaphragms and solenoids will last longer (due to less usage)
- Less maintenance and related plant down-time due to dust collector issues
- More consistent and increased air flow due to a lower pressure drop
- Better pick-up velocities and better plant hygiene due to better air flow
With the use of PTFE membrane bags and on-demand cleaning, your system should perform at its peak and provide all the benefits mentioned above. We recommend that these bags and timers be utilized in nearly every application to save costs all around and allow peak system performance.