<prompt> Translate the following text to EnglishFGD mifumo ya mapema walikuwa iliyoundwa na kutoweka tofauti, au prescrubber, mifumo ya baridi flue gesi kuja mbali kifaa cha kudhibiti chembe.  <response>: Early FGD systems were designed with separate quenching, or prescrubber, systems to cool the flue gas coming off the particulate control device. 