Sensors and interface devices for explosion protection

Wilhelm Niemann Maschinenfabrik based in Melle, Germany, manufactures mixers and mills for the production of paint, varnish, adhesives or silicones. The dissolver is suitable for mixing processes but also for dispersing – through which a rotating toothed disc splits solid materials into a liquid, mills it and mixes it. The result could then be a wall paint. The basket mill offers an even finer milling of predispersed material. The suction of a pump disc pulls the product through a basket filled with ceramic pearls with an action that is used by manufacturers of car paint. In order to move highly viscous products, the circular dissolver "Butterfly" features a centrally positioned butterfly tool to which scrapers are fitted on the outside. Depending on the requirements of the product, customers choose one of these basic types, but place far more requirements in practice on the quality of the machines

Safety in restricted space

Niemann generally follows two systems, with and without central control. Since many companies do not employ PLC programmers or bus technology is not necessary at all, variants with hard wiring instead of PLC are also offered. This sends signals from the operator button to the field via IMX12 isolating switching amplifiers from Turck. Devices from the IMX12 interface series are also used if users wish to pass certain digital or analog values from the Ex area. The data from proximity sensors or temperature values are thus run as intrinsically safe signals to the control cabinet. Turck's isolating switching amplifiers IMX12 were chosen here thanks to their narrow width of only 12.5 millimeters, but also due to their power supply via a power bridge.