3 Design of Mixing Units - Herbst Planetary Mixer

3.3 Application of Mixing Units in Ex-Zones 21• Tooth Pastes• Eye Shadows• Perfumes• light curing finger nails3.2.3 Food Industry• Flavourings• Fruit Concentrates• Chocolate Products• Salad Dressings• Delicatessen salads• Cream Cheeses• Marinades• Spice Mixtures3.3 Application of Mixing Units in Ex-Zones3.3.1 IntroductionIn the past it was sufficient to design the electronic construction parts of a mixing unitaccording to their intended application in ex-zones. Since this transition period ended onJune 30th 2003 all mixing units have to be designed according to ATEX regulations [2].As a result (in the following) also all mechanical components of a mixing unit will have tocomply with the special requirements of an operation in Ex-zones. Further informationon explosion protection see [3, 4, 5, 6].3.3.2 Ex-Protection in Mixing UnitsStirring and mixing units are classified as Other Operating Equipment(supplies) of GroupII. Table 3 shows a survey of the design significant datas.Classification of areas, the establishing of temperature classes and explosion groups is theresponsibility of the operator. The result of the danger assessment is to be recorded in theexplosion protection document and up-dated continually. This data allows the equipmentmanufacturer to design the mixing unit accordingly. The following is a prerequisite forthe design of agitation and mixing equipment for ex-zones.