<prompt> Translate the following text to EnglishKatika baadhi ya kesi, hata hivyo, mbinu preferred imekuwa kuweka SCR reactor juu ya ardhi karibu boiler na njia ductwork kwa na kutoka SCR reactor.  <response>: In some cases, however, the preferred approach has been to locate the SCR reactor on the ground near the boiler and to route the ductwork to and from the SCR reactor. 