Chemical Container Overpressure Relief System Design And Research

Supperpress venting of vessel is an important safety issue in modern chemical plant. An explosion and great loss will be caused if the supperpress of the vessel will not be solved in good time. As a result, it is very significative for the property of the nation and the safety of the people to research how to vent the supperpress vessel in time. Yet a unitive and exact scheme still has not been worked out due to the complicated venting process. A lot of developed countries set the pace in this field. Many authoritative organizations such as API(American Petroleum Institute),ASME(American Society of Mechanical Engineers), ISO(International Standardization Organization) and NFPA(National Fire Protection Association) have presented integrated approach respectively aiming at different aspect.In this paper, venting of pressure, venting of deflagrations of gas mixture and venting of deflagrations of-dust mixture have been investigated. And a program for venting design which is used widely and easily and exactly is programmed.This paper summarizes the research status of this area. The emphasis is laid on the design strategies, design models and some comments are made on these respects. Based on the energy and mass balance, Two hydrodynamics ingredients which affect the compressibility factorC have been derivative,and the simple calculate formula is gained.Based on the analysis of the codes for venting of pressure, the program has been designed according to API520. And the method of design of the venting of deflagrations of combustible that is commendatory by NFPA68 has been discussed, and the excellence and shortcoming are analyzed. The program is designed according to NFPA68.The program which is written with Visual Basic 6.0 is used easily and the interface of the program is very friendly and visual. Because of the too many database of state characters founded by Access2000 in the program, not onlythe user of the program is free of data input, but also the function of automatization of the computer are realized adequately. The database is linked with the program by DAO(Data Access Object), and update by users is allowed. The program for venting design has been checked up by factual examples and the error of the design is under 6%,The users can do the following venting designs:(1) The supperpress venting of the vessel which is full of steam;(2) The supperpress venting of the vessel which is full of gas compressor;(3) The supperpress venting of the vessel which is full of liquefied gas;(4) The supperpress venting of the vessel which is full of liquid;(5) The supperpress venting of the vessel which is full of liquid and vapor;(6) The venting of deflagrations of gas mixtures in the low strength vessel ([P]<0.01MPag);(7) The venting of deflagrations of gas mixtures in the high strength vessel ([P]<0. 2MPag);(8) The venting of deflagrations of dust mixtures in the low strength vessel([P]<0.01MPag);(9) The venting of deflagrations of dust mixtures in the high strength vessel([P]<0. 2MPag);(10)The venting of deflagrations of combustible in the enlongated vessel;...