摘要:
A flexible tube for an exhaust pipe for an automobile includes a bellows member (10) corrugated to have alternate ridges (11) and furrows (12) along its outer periphery; outer braids (20) provided to enclose the bellows member (10); fixing caps (30) fitted onto both side ends of the outer braids (20) respectively; and a spring member (40) provided on a circumferential surface of the outer braids (20). The bellows member (10) has lower ridges (13) in its center as well as regular ridges (11) on both sides thereof to more effectively absorb over-vibration of an exhaust system of an automobile and to enhance durability of the bellows member (10).
摘要:
The method of preparing a chromium oxide catalyst for preparation of pentafluoroethane using a chloroethane compound includes heat treating chromium hydroxide powder at a temperature not higher than 300° C. to obtain chromium oxide powder, heat treating metal hydroxide, at a temperature not higher than 300° C. to obtain metal oxide powder, mixing 85˜99.5 wt % of the chromium oxide powder with 0.5˜15 wt % of the metal oxide powder to obtain a mixture, forming the mixture into a pellet, calcining the pellet at 200-300° C. using nitrogen gas, and fluorinating the pellet at 300-320° C. using a gas mixture including N2 and HF, and then at 320-380° C. using HF gas. The fluorination catalyst prepared using the method of this invention can be effectively used to prepare pentafluoroethane at a high yield using a chloroethane compound.
摘要翻译:使用氯乙烷化合物制备五氟乙烷的氧化铬催化剂的方法包括在不高于300℃的温度下热处理氢氧化铬粉末,得到不高于300℃的氧化铬粉末,热处理金属氢氧化物 ℃,得到金属氧化物粉末,将85〜99.5重量%的氧化铬粉末与0.5〜15重量%的金属氧化物粉末混合,得到混合物,将混合物形成颗粒,在200-300℃下煅烧沉淀 ℃,并使用包含N 2 H 2和HF的气体混合物,然后在320-380℃下使用HF气体在300-320℃氟化颗粒。 使用本发明的方法制备的氟化催化剂可以有效地用于使用氯乙烷化合物以高产率制备五氟乙烷。
摘要:
The present invention provides a flexible tube for an exhaust pipe for an automobile, which comprises a bellows member (10) corrugated to have alternate ridges (11) and furrows (12) along its outer periphery; outer braids (20) provided to enclose the bellows member (10); fixing caps (30) fitted onto both side ends of the outer braids (20) respectively; and a spring member (40) provided on a circumferential surface of the outer braids (20). The bellows member (10) has tower ridges (13) in its center as well as regular ridges (11) on both sides thereof to more effectively absorb over-vibration of an exhaust system of an automobile and to enhance durability of the bellows member (10).