Production of liquid and gas air separation products (nitrogen, oxygen, argon, etc.) needed for metallurgical, chemical, and other industries is a complex technological process. Important parts of this process include monitoring the concentration of the components (the composition of the impurities, moisture, etc.) in the process streams and apparatus, and the methods used to obtain products (liquid or gas) of a specified degree of purity. Modern requirements for a high level of automation in air separation installations (corresponding to international standards) has made us think about designing high-reliability and promising methods and devices for gas analytical monitoring, and are why we need to systematize the knowledge accumulated by the Kriogenmash OAO during studies av.d operating experience with air separation installations, from the viewpoint of analyzing the operation of the algorithms and regulation loops for both individual units and for the installation as a whole.As an example, in Table 1 we give a list of analytical parameters which we must monitor for operation of a medium-capacity air separation installation with automatic control and regulation.Analyzing the data presented, we should note that along with a broad spectrum of gas analysis monitoring problems, we also need to solve the problem of automatic regulation of the gas components in the process streams and the pure products. In this case, the number of automatic regulation loops steadily increases. For example, comparative analysis of the technical and economic effieieneies of different approaches to solving the problem of providing the user with product nitrogen of the required quality has shown the advantages of the method of automatic stabilization of the volume fraction of oxygen (as the major impurity) in pure nitrogen at a level below the permissible value [1].In order to understand the essentials of the problem, let us consider the results of investigating a mathematical model for a system for regulating the volume fraction of oxygen in pure nitrogen via response to the flow rate of pure nitrogen reflux [2]. Without dwelling on the possible alternatives for realization and the advisability of designing multiloop systems for automatic regulation of the purity of the end product [3, 4], we note that the major problem from the standpoint of gas analysis is to ensure the required metrologieal and dynamic characteristics of the measurement channels. If this problem is not solved, the automatic regulation method is not very effective and is no longer appropriate.For example, let us consider one of the problems: the variation in the time required to establish the readings To 9 in the measurement channel in gas-analytical monitoring. In fact, the time To 9 is the basic dynamic characteristic and determines the time over which the readings (the output signal) of the gas analyzer are changed by the amount a=o,9{ c~-Co),after a change in the concentration of the analyte component at the inspection point, where Co is the initial concentration ...
