一、概述随着我国化学工业的发展,近年来陆续从国外成套引进了一批大型化工生产装置。例如1973年以后,从国外引进的13套年产30万吨合成氨48万吨尿素的大型化肥厂,年产30万吨乙烯的大型石油化工厂等。这些装置中有不少超重、超限的大型 I. Overview With the development of China’s chemical industry, in recent years, a large number of large-scale chemical production facilities have been introduced from abroad. For example, after 1973, 13 large-scale chemical fertilizer plants that annually produced 300,000 tons of synthetic ammonia with 480,000 tons of urea, and large-scale petrochemical plants that produce 300,000 tons of ethylene per year were imported from abroad. Many of these devices are overweight and oversized