Method for configuring temperature rise heat exchanger of sulfur dioxide conversion in series

Abstract

This invention discloses a method for series disposition of two heat exchangers for SO2 conversion and heating. The method comprises: (1) connecting two heat exchangers in series, introducing high-temperature flue gas from the combustion furnace into the top of the first heat exchanger, and and exhausting from the bottom into the second heat exchanger; (2) introducing SO2 process gas into the second heat exchanger, performing reverse-flow heat exchange with the high-temperature flue gas, introducing into the first heat exchanger, performing reverse-flow heat exchange with the high-temperature flue gas, and exhausting from the second heat exchanger; (3) completely exhausting tail flue gas by induced draft fan. The series connection of two heat exchangers can enlarge heat exchange area, and improve heat exchange effect. The utilization of the induced draft fan for exhausting tail flue gas can increase the heat utility, lower the exhausting temperature, and lower the consumption of diesel for heating. When high-temperature flue gas is introduced into the top of the first heat exchanger, the support of the tube plate is not directly contacted with the flue gas, thus the problem of ablation deformation can be solved. Therefore, the restriction crack phenomenon of the heat exchangers does not occur, and the service life of the equipment is largely prolonged.

Description

technical field [0001] The invention relates to a process method for converting sulfur dioxide into a temperature-raising heat exchanger, in particular to a method for configuring the temperature-raising heat exchanger in series. Background technique [0002] Sulfuric acid production uses pyrite, sulfur or other sulfur-containing substances as raw materials to produce SO 2 gas, then SO 2 The gas is oxidized and converted to SO in the catalytic bed at a temperature higher than 400°C 3 , and then react with water in the absorption tower to obtain sulfuric acid. In the catalyst bed, before the start-up enters normal operation, the process gas entering the bed should be heated by a heating heat exchanger, so that the catalyst bed can reach a temperature above 400°C required for start-up. The existing method uses a single heating heat exchanger, which takes a long time during the heating process, and it is difficult to raise the temperature after the temperature reaches 380°C ...

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Problems solved by technology

The existing method uses a single heating heat exchanger, which takes a long time during the heating process, and it is difficult to raise the temperature after the temperature reaches 380°C in the late stage of heating. ), the over-temperature operation can meet the heating requirements of the conversion system; secondly, the heat utilization efficiency of a single heat exchanger is low, and the exhaust gas temperature of the heat exchanger reaches 350°C or higher and it is directly vented

The lower tube plate of the heat exchanger is overheated due to direct ablation of high-temperature flue gas during the heating process, resulting in deformation of its support

The lower tube plate bears weight and high temperature at the same time, which may easily cause heat exchange tubes to crack and leak process gas (SO 2 ), resulting in high maintenance costs, which is not conducive to the production of the device

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