這幾句該怎麼翻譯才順呢?The PURASPEC vessels? 1. The PURASPEC vessels should be depressurised at a rate that ensures that the bed does not fluidise and is not damaged. In any event, the rate should not exceed 10 bar/minute above 10 barg or 1 bar/minute below 10 barg. 2. It is recommended that the system is pressurised at rates of not greater than 1 bar per minute below 10 barg and 10 bar per minute above 10 barg. This is normally achieved by the use of small bypass valves. 3. The vessels should be purged with nitrogen until the purge gas is free of hydrocarbon. A heated nitrogen stream may allow the purging to be completed over a smaller time period. This should begin at the earliest stage that the shutdown procedure allows and will enable any hydrocarbons, which may be adsorbed onto the PURASPEC material to vent off. During this period the operator will regularly monitor the vessel for signs of hydrocarbons in the purge stream.查看更多1个回答 . 4人已关注
can still benefit of 是什么意思(脱金属催化剂)? These first catalysts (demetallization catalysts) have the main job, in the refining objective, to remove the main part of the contaminants of the feed and especially to retain the majority of the metals contained in the feed. To do this, these catalysts must be able to convert preferentially the resins and asphaltenes in which most of these metals are found, and to have a considerably greater retention capacity than that of refining catalysts and then to protect them. Therefore, in order to protect the refining catalyst and to reduce at the same time the catalyst consumption in the downstream RFCC unit, the use of a specific demetallization catalyst is mandatory. This solid, thus must have a large pore volume and a pore distribution specially designed with macropores, so that resins and asphaltenes can move quickly through the grain mass and mesopores, so that these large molecules can still benefit of a large active surface area. 关于脱金属 催化剂 的,最后一段不好理解,特此请教标红句的翻译(或理解)。 查看更多4个回答 . 5人已关注