英国一家公司发明了一种新型气焊枪,它可以熔化钢块。与普通气焊枪不同的是,它可使用家用煤气或丙烷,而不使用昂贵的乙炔,同时不需要供氧。在原理上这是140年前德国化学家本生发明的气焊枪,但发明者在结构中加入了第二火焰,该火焰预先加热输送到焊枪中的燃气和空气达到50... A British company invented a new type of gas torch that melts steel. Unlike conventional gas torches, it can use domestic gas or propane instead of expensive acetylene and does not require oxygen. In principle, this was a gas torch invented by a German chemist 140 years ago, but the inventor added a second flame to the structure which preheated the gas and air delivered to the torch to 50 ...