Gas Distribution Structure and Control Method of Divided Plate Distillation Column

Abstract

The invention discloses a gas distribution structure of a clapboard-type rectification tower. In the regions on both sides of the clapboard and between two adjacent mass transfer areas, several layers of pressure-adjusting and dropping tray assemblies are arranged along the height direction of the tower. It includes trays, gas risers, downcomers, and caps. One of the gas risers is equipped with a gas flow meter; the tower wall is equipped with a feed port and a liquid collection port, and the circulation between the liquid collection port and the feed port The pipeline is equipped with a liquid flow meter, a regulating valve and a circulation pump, and a pressure gauge is installed in the area formed between the adjacent pressure drop trays; the sensitive plates in the mass transfer area on the left and right sides of the partition are respectively equipped with a temperature gauge. Table; process parameters are transmitted to DCS, circulation pump and regulating valve are controlled by DCS. The present invention designs a brand-new internal structure and external control process for changes in parameters such as energy consumption indicators, raw material composition, feed state, and product quality, which reduces the difficulty of overall control of the partition tower and enhances the overall control of the partition tower and The adaptability and controllability of its control system.

Description

technical field [0001] The invention relates to a gas flow distribution and control system on both sides of a partition plate rectification tower in chemical engineering, in particular to a highly flexible and robust gas flow distribution and flow control method for gas-liquid mass transfer. Background technique [0002] The industrial distillation process is a high-energy-consuming operation unit, so engineers and researchers from various countries in the world are studying the problem of how to separate multi-component systems at low cost and low energy consumption, and have extensively and deeply explored various The process, equipment and operation mode, especially thermally coupled rectification represented by clapboard rectification, have successfully realized many industrialized devices. Since 1985, BASF Company, UOP Company, Kohn-Glitch Company, Linde Company, Kellogg Company, Companies such as Kyowa Yuka and Sunitomo Heavy Industries have begun to use partitioned re...

AI Technical Summary

Problems solved by technology

The main disadvantages of this technical solution are: firstly, since the gas phase is extracted and the gas phase re-enters the tower, it is necessary to install a gas phase redistribution device in the tower, so the tower height and the complexity of the internal parts are increased; secondly, for the larger production capacity In the bulkhead tower, the diameter of the bypass gas-phase pipelines 54a, 54b will be very large, and the installation and maintenance of related components will be inconvenient; again, for the bypass gas-phase pipelines 54a, 54b with regulating valves 56a, 56b and flow meters 58a, 58b, Not only does the tower height increase, but the characteristics of the gas flow pressure drop will also become very complicated. If the pressure drop is too large, the downcomer 48 below the partition 120 will flood, and the system will not work normally; finally, the adjustment valves 56a, 56b The size varies with the size of the device, and the investment will become very expensive. More importantly, among the valve types in the prior art, there is almost no valve that can sensitively and accurately regulate the gas phase flow in a lower resistance drop range

The main design defects of this device include: firstly, there are irregular control performance curves in the adjustment of gas flow by the square valve plate, it is not easy to realize fine-tuning, the regulation control is poor, and the gas volume is nonlinear; secondly, due to the gas volume feedback to the upper side of the partition After the mass transfer area, the resistance drop reaction of the gas on both sides of the partition 22 will lag behind, and there will be negative feedback after being fed back to the controller 33. The square valve plate does not have fine-tuning characteristics, which will cause the square valve plate adjustment mechanism to continuously perform positive and negative adjustment actions , it is difficult to achieve stable regulation; thirdly, due to the use of a square valve plate to adjust the opening, the airflow behind the valve plate is mainly in the form of turbulent flow, and it is difficult for the flow detection device to accurately detect the actual gas flow rate; finally, due to the transmission parts in the tower, the lubrication It is difficult to solve the problem of wear and tear, which will affect the long-term normal operation of the equipment

[0008] Due to the fact that there are many operating variables in the thermal coupling process of the clapboard rectification column, and many parameters are coupled with each other, especially the physical relationship between the gas flow on both sides of the clapboard and other variables is relatively complicated, so many scholars and researchers at home and abroad believe that this Parameters cannot become directly controllable variables. However, the effective distribution and robust control of gas on both sides of the partition is an important means to ensure product indicators and reduce energy consumption. If the process control target cannot be achieved, then the advancement and economy of the partition tower will be greatly discounted

There are still many defects in the existing technical solutions of air distribution control methods at home and abroad, and there is an urgent need for advanced technical means to solve this industrial problem

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