Industrial filtration for the chemical industry

What is filtered, and why

Reaction media and mother liquors come first: a solid is separated from a liquid, a product is recovered, or the next step is protected from carry-over of particles. Filtration is part of the process there, not part of maintenance.

Clarification of finished products next, where the requirement is no longer only to retain but to add nothing: a medium that releases fibres or extractables into a product intended for sale is a quality defect, not a filtration defect. That constraint is specific to this sector, and it steers the choice towards constructions whose behaviour is known.

Solvents, acids and bases in service, whose filtration protects circuits, pumps and seals.

And finally air, in two forms: air handling for the rooms, and dust capture at powder handling stations. Activated carbon comes in when it is gaseous species that must be retained, which particulate filtration does not do.

The constraints of the environment

Chemical compatibility is the subject, and it is not settled by a table. It depends on concentration, temperature and exposure time taken together: a material that withstands a dilute acid when cold may degrade in a concentrated one when hot. We therefore start from the product safety documentation and from the medium manufacturer’s compatibility table, and decide case by case. It is also why our medium selection guide publishes the temperature scale that is genuinely evidenced and does not publish a compatibility matrix: one wrong line in such a matrix leads to choosing a medium that dissolves.

Solvents add a mechanism that corrosion does not have: swelling. Some materials deform without degrading chemically, and a swollen element loses its seal inside its housing — the failure is mechanical while the cause is chemical.

Temperature adds to chemistry and shifts the limit of the complete element: medium, frame, adhesives and gaskets each have their own, and the lowest one governs.

And finally campaign changeovers. An installation producing several products in succession requires cleaning, sometimes an element change between two batches, and always a compatibility check against the new medium.

What outsourcing the purchasing function changes here

Requirements are numerous, individually modest, and spread across workshops that do not buy together. This is the configuration in which the purchasing function costs the most per reference, and the one where outsourcing it changes the most.

We identify the right element from the medium and the objective, approach several manufacturers for the same requirement, and group a site’s supplies. When no market reference fits — a non-standard dimension, a medium imposed by the process — the element is made to drawing or to sample.

What to tell us

The medium and its safety documentation; the service temperature and pressure; the flow; the fineness expected, or the result expected if you do not know the fineness; the dimensions of the element in place and its marking; the type of housing. Do say whether the filtered product is intended for sale: that changes which constructions are possible.