Heat exchange and flame arrest

A gas evacuation system for a printing device, comprising:

• an evaporation channel defined in part by a surface of an intermediate transfer member (“ITM”), a nozzle of an air knife heated by a heat source, and a mixing zone, wherein the mixing zone is connected to a gas flow inlet of a heat exchange and fire arrest (“HEFA”) device;
• the HEFA device for use with a subject gas, the HEFA device including
• a core including the gas flow inlet, a set of cooling fins, and a gas flow outlet, wherein the gas flow inlet, the set of cooling fins, and the gas flow outlet collectively form a gas flow pathway;
• wherein the gas flow inlet is for receiving the subject gas from the mixing zone;
• wherein each cooling fin of the set is positioned to form a gap between that cooling fin and an adjacent cooling fin, the gap greater than quenching diameter for a subject gas;
• and
• tubing arranged to traverse the core, the tubing defining a cooling fluid pathway;
• wherein the combination of the gap between each cooling fin of the set and the cooling capacity of the cooling fluid pathway is sufficient to lower temperature of the subject gas to below a kindling point, and to at least partially condense the subject gas.