Apparatuses, devices and combinations thereof and members or components of such a nature, namely cleaning appliances using steam, disintegrators, condensors, catalytic converters, dust removing installations for cleaning purposes, gas condensors and air condensors, all of the foregoing for the removal of environmentally hazardous nitrogen compounds from waste gases by the reduction and/or removal of nitrogen (II) oxide (N20) through catalytic-chemical decomposition of nitrogen oxides (NOx) an...