In industries such as pharmaceuticals, biotechnology, medicine and food, purity is of utmost importance. Contamination-free ambient air and a work station made of high-quality stainless steel are therefore particularly important. Through the use of an air-technical protective measure, the Laminar Air Flow Booth, airborne particles and microorganisms are removed from the ambient air. The booth thus serves in particular to protect people and to keep the product clean.
The Laminar Airflow Booth provides a dust and particle-free environment with a HEPA filter. A laminar (low-turbulence) flow is generated over the entire ceiling surface, directed vertically towards the floor ("Laminar Down Flow"). With a high air velocity of 0.475 m/s, airborne particles are effectively pushed downwards in the entire working area and extracted near the floor - airborne substances are thus captured in a controlled manner.
Typical use cases/areas are:
Product sampling areas
The suitability of air protection measures, such as the laminar air flow cabin, must be determined depending on the occupational exposure limit values (OEL) to be complied with.
The OEL limit values are assigned to so-called Occupational Exposure Band (OEB) classes in six interval gradations. For example, a substance with an OEL value of 3 µg/m³ corresponds to OEB 4. The classification is associated with different requirements for the technical system.
DENIOS guarantees an OEB class 3 (Hazardous) for the Laminar Air Flow cabin, which corresponds to an OEL of 10-100 µg/m³. Lower classes are also fulfilled. In addition, it is possible to achieve higher OEB classes by having individual approvals and tests carried out by external testing companies.
Potentially contaminated air is drawn in via the rear wall. There, the air is first treated by a pre-filter, for example an ISO Coarse filter. This is followed by a second filter stage ePM1-80%. An additional HEPA filter stage (HEPA 13) is then installed. For demanding requirements, a terminal police filter (HEPA 14) can be installed, which brings an additional filter stage and more safety into the process if the air is run in recirculation mode. In this case, the filtered air corresponds to clean room class ISO 5 according to ISO 14644-1.
Of this filtered air, 90% is returned to the working area via the ceiling area. The remaining 10% is blown out in front of the working area via the front blow-out plenum in the ceiling area. Thus, a negative pressure is created in the work area and the remaining air is taken from the area in front of the work area. Workers are effectively protected from exposure by the high air exchange rate and the targeted air routing. In addition to personal protection, a laminar air flow booth in this design offers increased room and product protection, as the airborne particles cannot escape from the booth due to the negative pressure.
1: Extraction grid
2: Coarse dust pre-filter
3: Fine dust filter
4: HEPA filter
5: Air flow control
Equipment and configuration options
The choice of equipment for the laminar air flow booth should be made in cooperation with the operator, as he knows his work processes best and can therefore define which tools, media and other elements are required. The required equipment should be determined before the booth is commissioned so that these components can be taken into account during the design phase. Subsequent installation is often only possible with great effort or not at all.
The tasks to be performed should also be clearly defined so that any special requirements can be taken into account in the design. On the construction side, media interfaces must be provided for electricity, network, technical gases and other supply lines, for example. The corresponding transfer points must be defined and coordinated in advance to ensure problem-free installation and commissioning.
Examples of special equipment:
Fully automatic air flow control
Extraction, fine dust and HEPA filters in safe-change filter casings for safe filter replacement
Supply air with heating/cooling elements
Electrical components in accordance with the ATEX directives for potentially explosive atmospheres
checked for proper installation, function and set-up before they are put into operation for the first time,
inspected at regular intervals, but at least once a year in the case of particulate air pollutants or at least every three years in the case of gaseous air pollutants; and
inspected after modifications that require
be inspected by a person qualified to carry out the inspection. The results of the tests must be entered in a test book or a test report, kept and can be used as a basis for the recurring tests.
It is recommended to replace air filters of the 1st filter stage after one year at the latest, and further filter stages after 2 years. In active pharmaceutical ingredient areas as well as in food applications, it is common practice that the 2nd filter stage is also changed annually. The sensitivity of the application, possible external audits, an unfavourable air humidity at the place of use or special risks may make a complete filter change necessary, e.g. if a long-term bacterial growth due to the dusts stored in the filter cannot be excluded.
Service and maintenance from DENIOS
The manufacturer's regular maintenance and servicing ensure that your product retains its value and protects your employees. Learn more about our service offer.