Heaters with feed and air preheated by hot flue gas and hotresidue oil respectively have attracted extensive attention.
管式加热炉采用“冷进料、热油预热空气”以提高热效率，受到了广泛的注意。
2
Before use, wash in hot soapy water, rinse and try thoroughly to remove any residue which may remain form the crafting process.
使用前﹐用热的肥皂水清洗﹐沥干并仔细移除任何在工艺加工中可能留存的残余物。
3
At this point residue or dirt particles are controlled to not build up or attach to hot engine parts or build up in the oil since the particles are suspended inside the oil.