Issues with the settings of the electric furnace after catalyst heating and reduction are completed when changing positions
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For the electric furnaces in our company whose operating roles have been changed, previously the system was isolated from them using valves or blind flanges after the catalytic heating and reduction process was completed; now, after the heating and reduction are finished and normal production resumes, these furnaces are connected to the system. Dear sea friends, please discuss which of these two approaches is better.
It is convenient to connect in when the system is powered on, and there is no need to install blind flanges. However, some electric furnace designs have a pressure rating lower than the system pressure, so a blind flange must be added after heating.
If the shift process employs a full low-temperature shift process and the shift reactor is equipped with an insulating lining, then during a short-term shutdown (of no more than 5 days), it is possible to restart the shift system without raising the temperature in order to allow gas flow; heating and sulfiding are required only after the catalyst is replaced. In such a case, not only must the design pressure of the electric furnace match that of the operating system, but this also leads to increased manufacturing costs. Moreover, the presence of such elements within the system in contact with the process gas can cause corrosion. If medium-low or medium-low-low processes are used, the shift converter is prone to temperature collapse, making it more convenient to use in such systems.
I think it’s better to cut off the system by installing blind flanges; having it connected to the system will make the process pipelines longer and more complex. If the design pressures of the two are different, it can also pose safety risks. As long as the operating procedures are followed strictly, a temperature collapse in the conversion process will not occur. It is certainly not advisable to keep the production running under such risks just to prevent an extremely rare occurrence of a temperature collapse.
In the medium-string low-flow process, the medium-voltage furnace is normally connected in series within the system; after all, during production there can be significant reductions in flow rate or the presence of water, which leads to a drop in the temperature of the catalyst layer, necessitating heating by the electric furnace. The low-voltage transformer is usually isolated from production, and its temperature can generally be raised using a hot feed line connected to the reaction zone of the medium-voltage transformer.
It is more convenient to have medium-low-low voltage transformation furnaces connected in series within the system
In many current cases, built-in electric furnaces are used for medium-low-low or medium-series-low configurations, while external electric furnaces are used for full-low configurations; this is related to the process design.