The gas generation and processing of the hydrogen plant is installed inside a cabinet or open skid. Several different solutions are available.
Fig. 1 Cabinet enclosure. Ventilation of the cabinet is obtained by natural air circulation. Air output is on the top of the cabinet. This kind of enclosure generates an ATEX II 3G zone around the cabinet, which must be installed in a correspondent classified room. Maintenance and plant inspection is executed through the front and back doors.
Fig. 2 Cabinet enclosure with air extracting fan. This solution is similar to the one displayed in Fig. 1 but the cabinet is equipped with an air extracting fan which evacuate outdoor possible hydrogen leakages thus avoiding the classification of the installation room. The air flow through the cabinet is actively monitored by the plant PLC and low flow alarms are activated.
Fig 3 & 4 Open skid. Different types of open skid structures are used depending on the size of the plant. The room where the open skid is installed gets classified ATEX II 3G. Advantage of this structure is the easy accessibility of all plant components also in case of large or very large plants.