... maintenance 5.ISO9001-2008:SGS Chain Grate Hot Air FurnaceHigh heat transfer efficiency with an overall efficiency of no less than 75 ... mechanized, stable running, and convenient operation Adaptable for various coals with heat generation value of no less than 4,500Kcal/kg ... , feedstuffs, chemicals, building materials, minerals, and more Chain Grate Hot Air Furnace with high efficiency