Research On The Corrosion Behavior And Inspection Strategy Of The Jacketed Stirred Tank Under The Circulation System Of Refrigerated Brine/Steam

Glass-lined stirred tanks,widely used in petroleum industries,chemical industries,pharmaceutical industries,food industries and various scientific research projects in universities,are often needed to pass frozen brine/steam to the jacket alternately to meet the cooling/heating production process requirements.In the process of project site inspection and safety inspection,it was found that the alternation frequency of frozen brine/steam,service cycles,concentration and p H value of the frozen brine,whether to add corrosion inhibitors,types and concentrations of corrosion inhibitors will affect the equipment jacket and its connecting pipelines.The above conditions might cause different degrees of corrosion,unplanned shutdown of equipment,and might affect industrial production and safety accidents,threatening the safety of equipment and workers.At present,literatures about corrosion of equipment in a single chilled brine system have been published at home and abroad.However,study on the corrosion of equipment in a chilled brine/steam cycle system was not researched.In the present article,firstly,the influences of different operating cycles and different exchange frequencies on the corrosion of the equipment in the system were obtained through the follow-up inspection and sampling analysis of the equipment in use;Secondly,by building a frozen brine/steam experimental system,the corrosion of Q235 B carbon steel pipe was studied and analyzed when the concentration of the frozen brine was 10% and 20%,service temperatures are 0? and room temperature,and the alternate frequency of frozen brine and steam was 5 min.and 10 min.,respectively.The methods of macroscopic inspection of appearance,microscopic analysis of pipe section metallographic microscope and ultrasonic thickness measurements were adopted for comparing and analyzing variation of wall thickness under different service conditions.The research results show that the faster the exchange frequency of frozen brine and steam,the faster the corrosion rate of Q235 B material in the steam/frozen brine system.The more the number of service cycles,the greater the amount of corrosion of Q235 B material.The quality of the insulation layer of the equipment in use also has a certain impact on the corrosion of the equipment,and the damage of the insulation layer will accelerate the corrosion of the materials under the insulation layer.According to the guidance of the experimental results,the optimal inspection strategy could be recommended during the device inspection.The optimal inspection plan could be recommended during the equipment inspection,and the user can formulate the optimal inspection plan and maintenance plan to ensure the safe operation and maintenance of the equipment.