Weighing Center Return Air
Series »WZU-KF«

Weighing Center Return Air Series »WZU-KF«


Laminar flow weighing center for a clean product, safety of the personnel and protection of the environment.
The air quality complies with:

  • ISO 14644-1 Cl. 5
  • the US Federal Standard 209e, Cl. 100
  • GMP recommendations are fulfilled.
  • Protection of personnel during work with highly hazardous substances is assured.

Video - Flow simulation:

Operation Principle

Laminar flow is a smooth unidirectional current of ultra clean filtered air flowing at a constant velocity. This air is drawn vertically downwards over the whole working area and flushes all air-borne particles liberated during work to the air intake ports. Depending on the requirements, the withdrawn air is passed either through a pre-filter or a combination of pre- and fine filters by means of a quietly running radial ventilator into the return air duct and then forced through the HEPA filter. The cycle starts again.

  • Air coolers can be mounted in the return air duct.
  • Cartridges with activated charcoal can be installed in the return air duct to adsorb vapours!
  • This equipment does not interfere with the laboratory air conditioning.

This arrangement guarantees:

  • Aseptic, highly clean Laminar-Flow working conditions
  • 99,999% removal of all air-borne particles Ø 0,3 µm
  • Optimal removal of dust over the pre-filter and final filtration through a HEPA filter.
  • Best personnel protection with a current of clean air flowing over the head of the worker.
  • 100% return air, low energy costs and long filter life.


  • The fine filter (Level 1) has to be changed after 3-6 months of use.
  • The fine filter (Level 2) has to be changed after 10-14 months of use.
  • The HEPA filter has to be changed after 7-10 years of use.

Quality Specification

Important for the proper function of the laminar flow equipment is the permanent and air-tight seating of the HEPA filter. We achieve this by means of an assembly system which is certified by the state authorities for use in nuclear plants.
Our laminar flow equipment complies with:

  • the Standard ISO 14644-1,
  • the GMP und PIC guidelines
  • and passes all FDA-inspections.

Air-tight seating of the HEPA filter is guaranteed.

Optional extras

  • Housing made of stainless steel 1.4404 (V4A) laquered both on inside and outside
  • Adaption to all kinds of power supplies and frequencies
  • Limits of Laminar Flow area made of transparent 0,5 mm thick PVC foil
  • Finely adjustable ventilators, explosion-proof fabrication (EExe II T4)
  • Laminar Flow limits finished with an antistatic film in explosion proof equipment
  • Also possible to suspend from the ceiling
  • Air intakes for floor and table weighers