Pharma

The top-mounted filter unit with Wash-in-Place (WIP) function (here series 05) is placed on a tank. The raw gas chamber can be flushed with water by means of built-in tank cleaning heads. An optional lifting/swivelling device facilitates the removal of the filter elements on the clean gas side for the cleaning process.

Integrated cleaning systems are often used in dust extraction systems wherever increased demands are made on hygiene. Here, an application example from the pharmaceutical industry is used to demonstrate how the cleaning effect of a filter unit with WIP function (Wash-in-Place) can be proven. Furthermore, criteria are explained that must be taken into account when designing filter units for efficient cleaning and with regard to other industrial requirements.

Qualitative cleaning validation by means of a fluorescence test.

Fluorescence tests (e.g. the riboflavin test) are used, for example, in the pharmaceutical or food industry to check the cleanability of containers and their internals. The purpose is to identify areas that cannot be cleaned, which may be caused, for example, by geometric surface characteristics such as sharp edges, cracks, holes, undercuts, drill holes, narrow gaps or recesses. Riboflavin is a water-soluble vitamin of the B group with an intense yellow fluorescent colour. Non-cleanable areas are made visible in the riboflavin test by illumination with UV light due to the fluorescence of the marker molecule used (e.g. riboflavin).

Chemistry

The filter unit with bulk material discharge was extended here by an integrated filling by means of suction conveying.

• Due to the process, the filling level should not fall below a minimum level. The fill level is monitored by two level indicators.
• A customised suction nozzle is connected to a pinch valve for conveying the product.
• The suction is controlled via a second pinch valve.
• If the upper level indicator signals that the maximum filling level has been reached, the pinch valve to which the suction nozzle is connected is closed and the pinch valve with the connected suction unit is opened.
• The control and fan are active during the entire process.