[Recommendation] Production Technology: 【Daily Question】Wednesday, 07/06/2011

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This post was last edited by *nyang3390 on 2011-7-7 08:54. Production Technology: 【Daily Question】Wednesday, 2011.07.06 1. Regarding the design pressure for chemical processing equipment, which of the following four statements is correct? (　). A. The maximum operating pressure of a chemical processing equipment can be used as the design pressure for that equipment. B. Design pressure refers to the highest pressure that a vessel can withstand. C. Design pressure denotes the maximum pressure at the top of the vessel, and this value is not lower than the highest pressure encountered. D. Design pressure is the maximum operating pressure of the vessel, plus any additional pressures resulting from the conditions in the process system, representing the pressure that may occur within the vessel. 2. In extraction, the selectivity coefficient β corresponds to which parameter in distillation? （　） A. Volatility v B. Saturated vapor pressure of the component P0 C. Relative volatility a D. Phase equilibrium constant K Please hide restore 1. [Answer] C [Explanation] The design pressure refers to the maximum pressure at the top of the container (including any additional conditions imposed by the process), and this value must be equal to or higher than the highest pressure that occurs. A is the wrong answer. The maximum operating pressure refers to the highest pressure that can be reached at the top of the container under normal operating conditions. Since the container must be able to withstand the pressures that may occur under various operating conditions, it cannot be used as the design pressure for the equipment. B is the wrong answer. D is the wrong answer. The maximum pressure that can be reached at the top of the container, resulting from the container’s maximum operating pressure plus the additional conditions in the process system, refers to the peak pressure. The reference pressure used to determine the design pressure of a container is not the design pressure itself; the design pressure of a container must be at least as high as the maximum pressure. 2、C