Electric air heaters are employed to preheat air and gases in the chemical and pharmaceutical industries. In process engineering, set process temperatures are often required, for example when paper webs are dried in printing machines, vessels and solvent containers are dried with hot air after cleaning, or reactions are initiated with streams of heated gas.
When the pressure of a gas is reduced, its adiabatic expansion is accompanied by a fall in temperature, which can be calculated from the ideal gas equation (Tompson effect). In order to prevent ice forming in valves, fittings and piping, the gas stream is heated up prior to the reducing valve by the calculated temperature difference required. We supply the explosionproof heaters together with pressure vessels up to a maximum pressure rating of 150 bar. This not only ensures safe operation but also guarantees the greatest possible availability of the gas. The pressure vessels of course comply with the requirements of the Pressure Equipment Directive 97/23/EC and the AD 2000 Code drawn up by the German Pressure Vessel Association.
Various concepts are available for heating liquids. Flanged heaters with welded-in heating elements are manufactured with flameproof enclosures and terminal boxes with increased safety 'e' type of protection. Large storage vessels are equipped with heaters whose heating element can be exchanged without draining the vessel. For applications requiring particularly small dimensions, heating elements with a diameter of 12.8 mm, connected at one end, can be used.
Our thermal fluid units are available for heating reactors. These are designed as complete systems, consisting as a rule of a pump, an electric heater, possibly a cooler, an expansion vessel and the associated piping.
Our complete series of PID temperature controllers is designed for incorporation into explosionproof control units. An intrinsically safe remote control system permits operation from outside the hazardous area. The temperature sensors with Zener barriers provide accurate results, since the software compensates for the internal resistance.