Blowing Machine

a unit used for compressing and delivering air or some other type of gas. Blowing machines are classed according to their compression ratios: fans (up to 1.1), superchargers (above 1.1 without intermediate cooling of the air during compression), and compressors (above 2 with intermediate air cooling). Blowing machines are sometimes referred to as blast blowers (in the iron and steel industry) or draft blowers (in boiler units).