My filters are clogging too quickly. What can I do?
At first glance, filtration (liquid-solid separation) is an operation that may seem simple, but in fact it involves a complex set of physical, electrostatic, chemical phenomena which are all governed by the laws of fluid flow.
The principle of filtration being to retain particles by means of a media or support the first phenomenon that will be observed is the clogging of the pores of the media or support by the undesirable particles. The result that follows is simple : it must be replaced or cleaned. If this operation is not carried out in time, you will notice a drop in flow rate and therefore productivity, or an increase in pressure, depending on the type of pump used, with repercussions in terms of productivity, risks of deterioration of your equipment, risks for your operators and energy consumption for your entire installation. In some cases, clogging can even lead to mechanical failure of the filter media, which will then release all retained particles.
Proceeding with filter replacement or cleaning is essential, but it is also an operation that requires shutting down production while maintenance is performed. Therefore, the frequency of these shutdowns should be minimized.
To avoid premature clogging of your filters, it is important to choose them well and size them correctly. In the event of too frequent clogging, the first step is to have a detailed assessment of existing filtering devices performed by an expert in the field, in order to find the best possible replacement solution. The initial extra cost of this operation will be quickly amortized thanks to the financial savings made in terms of maintenance and energy consumption. In addition, slowing down clogging will reduce the waste produced.
What aspects should be considered to slow down clogging?
As previously mentioned, there are numerous factors influencing filtration and they interact together.
A precise knowledge of the nature of your solution to be filtered will allow you to make a relevant technological choice on the type of filtration to use:
- The type of particle size distribution, usually represented by a Gausse curve, will indicate whether you need to work with a media with clarifying or classifying properties.
- The nature of the particles (crystallization, chemical nature, hardness,…) will influence the need to use a depth, surface or adsorption media
- The quantity of solids to be retained, the desired flow rate and the need to work continuously or in batch are notions to be taken into account.
- It is also very important to take into account the conditions of your process. The temperature is an important element because it can condition the choice of the media. Temperature variations also have an impact on the media because the structural deformation of a filtration media linked to a strong temperature variation influences the clogging.
- The chemical nature of the fluid and the particles to be retained is an important factor because an incompatibility can lead to a destruction of the media or a pollution of the filtered solution by the dissolution of compounds.
- The viscosity of the solution is also a factor to be taken into account because its impact on the pressure drop is directly proportional.
Which solutions?
An early clogging of a filter is not an easy thing to solve because the factors are multiple and can add up. An analysis of your parameters, of your process allows you to know if you should :
- Add a pre-filtration stage (in case of high load, particle size distribution with several balance populations)
- Increase your filtering surface to avoid a too important initial pressure drop
- Reduce the specific filtration rate in case of compressible and deformable solids
- Check the compatibility of the media (chemical, temperature)
If you would like advice, to benefit from our experience, to reduce your filtration costs, do not hesitate to contact us so that we can help you find a more suitable solution!