Although the isolator target Operator Exposure Level (OEL) was <10µg/m3 the isolator is designed to the same specification as a system required to operate at OELs of <1µg/m3; the actual OEL achieved by the system when third party tested using micronised lactose was <0.01µg/m3.
In operation the drum is loaded onto the tipper, de-lidded and the safety gate closed. The pneumatic circuit is interlocked and will not allow the tipper to operate unless the gate is closed. The drum is raised, tipped and docked with the isolator; the drum rim and outer liner are sealed to the isolator using the Hosokawa drum dock system, which uses both compression seal and inflatable seal technology.
The bagged powder is removed from the drum into the transfer chamber and then moved into the charging chamber via the transfer door. The bag is opened using a Hosokawa safety knife and charged into the reactor below.
The discharge hopper is fitted with a grid to prevent bags and other objects falling into the vessel. Waste materials are removed via the continuous liner bag out port system. The isolator is ergonomically designed to ensure ambidextrous flexibility and offer overall user friendly functionality.
The system is certified for use in an ATEX II 3G (Zone 2) area. The main electrical cabinet is air purged, which prevents exposure of live electrical equipment to flammable gases. All electrical field equipment including pressure transmitters and proximity switches are connected via galvanic barriers to give intrinsically safe operation. The isolator operates with a nitrogen inerted, negative pressure internal atmosphere and the system controls a variable speed extract fan and incorporates interlocks to allow the safest possible operation.
HEPA filtration is used for the nitrogen inlet and the isolator extract and a HEPA filter is also installed between the transfer chamber and charging chamber to give a pressure cascade through the isolator to reduce the risk of the transfer chamber becoming contaminated. The system incorporates the Hosokawa safe change filter system as well as safe change gloves.
Contact T +44 1928 755100 F +44 1928 714325 {encode="info@hmluk.hosokawa.com" title="info@hmluk.hosokawa.com"} www.hosokawa.co.uk