Laminar air flow units protect high risk areas of bottling machines in Spanish cream milk production

© Freudenberg/Getty

HEPA filters of H14 filter class for final filtration in the laminar flow units. © Freudenberg

F45 R pocket filters for prefiltration in the fan filter unit /AHU and MVP 95 V08 cassette filters for final filtration in the AHU. © Freudenberg

Laminar flow units on top of the conveyor belt line protect open bottles during transport to the filling machine area. © Freudenberg

3D drawing of fan filter unit - to increase indoor air quality. © Freudenberg

Introduction

A Spanish food & beverage specialist in cream milk production had contamination problems in the filling lines and wanted to improve the hygienic air quality of the cleanroom and the conveyor belt and filling machine areas. The user was experiencing several process impairments with regard to air distribution and negative pressure in the high-risk areas. The analysis of the weak points lead to a clean engineering project with several solution approaches.

The initial situation

Our technical inspection of the production site showed the following weak points:

- Poor distribution and insufficient regulation of filtered air from the air handling unit leading to the cleanroom zone.
- No permanent control system for the air handling unit to check the performance i.e. the final pressure drop of each filter stage.
- Leakages on the room walls and access doors to the cleanroom.
- Negative pressure in the cleanroom compared to adjacent rooms and poor air changes per hour.
- Duct installation without air flow regulation dampers.
- Originally installed HEPA filters of the old laminar flow units produced detachment of solid particles from gel gaskets and painted protection grids passing to the cleanroom.

The Viledon® solution

The scope of this individually customized engineering project included engineering, manufacture, construction and assembly of new fan filter units and laminar flow units and an automatic data control & regulation system for monitoring of all laminar flow units. The filter stages of the existing air handling units were replaced by an efficient and energy saving filtration solution. Supervision for commissioning and start-up were also part of our project scope.

- Bigger laminar air flow units compared to the previous ones have been installed to avoid product contamination, to improve the air quality in the conveyor belt area and to create an overpressure into the highrisk area.
- In the final stage of all laminar flow units HEPA filters (filter class H14) with gel gasket and with AISI 304 protection grids were installed.
- To obtain overpressure and to increase air quantity and quality for the cleanroom, four new fan filter units were designed in AISI 304 and equipped with F45 R prefilters followed by HEPA filters of filter class H14.
- The existing air handling units were fitted with a 2-stage filtration system including F45 R pocket filters for prefiltration and MVP cassette filters in the final filter stage. Additionally, new air ducts with air flow regulation dampers were installed.

Customer benefits

- The hygienic indoor air quality, both in the conveyor belt line area and in the cleanroom filling machine area, is significantly improved and contamination is reduced to a minimum.
- The new engineering installations ensure that the air changes per hour are increased and the necessary overpressure on top of the conveyor belt lines is continuously achieved.
- All customer requirements for obtaining ISO 8 classification for previous rooms, ISO 7 classification for the cleanroom production room and ISO 6 for the conveyor belt zone could be met.
- The filter replacement in the air handling unit with F45 R reverse pocket filters in the 1st stage and MVP 95 V08 cassette filters in the final stage pays off through energy savings. Furthermore, due to their coalescing properties, the F45 R filters collect submicron moisture droplets, thus substantially reducing humidity ingress to the downstream filter stage.
- HEPA filters of H14 filter class with AISI 304 grids installed in the laminar flow and fan filter units ensure an effective control of contamination hazards for the high hygiene zones.