Industrial filtration
Industrial filtration separates solid particles from gas or air streams and is indispensable in every form of powder processing. For manufacturers in pharma, chemical, food and the battery industry, the filtration strategy determines whether a process runs dust-free, safe and GMP-compliant. HECHT designs filtration solutions that combine operator protection, product retention and process efficiency. This page explains the available techniques, how to select a filter, and what to consider regarding OEB bands, ATEX and hygienic design.
Why filtration is critical in powder processing
Every transfer, conveying step or dosing operation releases fine dust. That dust poses three risks at once: operator exposure, cross-contamination of product and explosion hazard with combustible powders. Effective filtration captures particles before they spread, keeps the working environment clean and protects downstream equipment from wear.
Correct filtration also lowers your OPEX. Less dust loss means higher yield, less cleaning and longer service life for pumps and fans.
Key filtration techniques
The choice depends on particle size, flow rate, dust load and the required separation efficiency.
- Cartridge filters — compact, high filter area per volume, ideal for fine dust and continuous operation
- Bag filters — robust at high dust loads and coarser particles, easy to maintain
- HEPA/ULPA filters — for critical separation up to 99.995%, essential in pharma and cleanrooms
- Cyclones — pre-separation of the coarse fraction, reducing the load on the main filter
- Sintered lamellas and metal filters — for high temperatures, aggressive media and cleanable applications
Cleaning: jet-pulse and mechanical
A filter inevitably becomes saturated. Cleaning during operation determines continuity. Jet-pulse cleaning uses a short blast of compressed air to release the filter cake from the medium, so the process need not stop. For containment applications, bag-in-bag-out (BIBO) designs let you replace the filter without exposure. Differential pressure monitoring tracks saturation and signals the right moment to clean or replace.
Filtration and OEB bands
For active pharmaceutical ingredients (APIs), the OEB band is decisive. The higher the OEB band, the lower the permitted exposure and the stricter the requirements for filtration and containment.
- OEB 1–2 — standard dust extraction with cartridge or bag filter often suffices
- OEB 3–4 — closed systems with HEPA final filtration and safe filter replacement
- OEB 5 — isolator technology, dual HEPA filtration and validated BIBO procedures
ATEX and explosion safety
Many powders are combustible. As soon as a dust-air mixture is ignitable, the installation falls under the ATEX directive. Filtration systems must then be designed with explosion-pressure-resistant housings, pressure relief, spark detection or an ignition-source-free design. HECHT supplies ATEX-compliant filter units with the correct zoning and documentation.
Hygienic design: GMP and EHEDG
In pharma and food, cleanability matters as much as separation. Filtration components built to GMP and EHEDG guidelines have smooth surfaces, no dead zones and are CIP/WIP-cleanable. Stainless steel 316L, FDA-compliant seals and validated cleaning procedures prevent cross-contamination between batches.
Filter selection in practice
Good selection starts with process data: which powder, which particle size distribution, which flow rate and which separation efficiency. From there you define the filter class, the cleaning principle and the containment requirements. HECHT calculates the filter area based on the permitted filtration velocity, so you neither over- nor under-dimension.
Frequently asked questions about industrial filtration
Which filter class do I need for pharmaceutical powder?
For APIs with a high OEB band, HEPA H13/H14 is the starting point, often combined with a pre-filter and validated BIBO replacement.
What is the difference between a cartridge and a bag filter?
Cartridge filters offer more area in less space and perform better with fine dust. Bag filters are more robust at high dust loads and coarser particles.
How often must I replace filters?
That depends on dust load and cleaning principle. With jet-pulse cleaning filters last longer; differential pressure measurement indicates the right replacement moment.
Is my process subject to ATEX?
As soon as a combustible dust-air mixture can form, ATEX applies. A dust explosion analysis determines the zoning and the required protection.
Can I combine filtration with existing equipment?
Yes. HECHT integrates filtration into existing conveying, dosing and filling lines, including the correct containment connections.
Related guides
Tailored advice from HECHT
Want to know which filtration solution suits your powder, OEB band and process? HECHT's specialists analyse your situation and design a system that protects operators, retains product and complies with GMP and ATEX. Contact us for a no-obligation consultation.