Temperature monitoring settings for butadiene spheres, anti-corrosion inside the tank
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This post was last edited by Memories of Tomorrow on 2020-4-8 at 15:07. Regarding butadiene spherical tanks, I have two questions for everyone: 1. Temperature monitoring inside the tank: For large-diameter spherical tanks (3000 cubic meters or larger), it seems to me that using thermocouples placed at the bottom of the tank, as is done with ordinary liquefied hydrocarbon tanks, cannot accurately reflect the temperature distribution throughout the butadiene spherical tank. In actual design, how should temperature measurement devices be installed to ensure accurate and uniform measurement of the butadiene temperature within the tank? What measures should be taken when the temperature exceeds the set limit to prevent the butadiene from polymerizing? 2. Internal anti-corrosion: For butadiene spheres made of carbon steel, rust may form during use due to factors such as moisture in the medium. I would like to know whether there are any precedents for implementing internal anti-corrosion measures on butadiene spheres I welcome suggestions from colleagues regarding the issues above~
Let me try to answer this myself: 1. Can temperature monitoring at different heights inside the tank be achieved by using multiple thermocouples inserted from the temperature sensor opening at the top? 2. To what extent does rust inside the butadiene tank actually affect butadiene polymerization, and is its impact less significant compared to that of relative temperature? I would also appreciate any guidance from fellow sailors who have practical experience in managing operations in this area~
1. This requires regular cyclic cooling, and top spray feeding can be used； Keeping the oxygen content in the tank below 50 PPm can reduce polymer formation ； It is safer to keep the temperature between 15-18 degrees ； When the temperature exceeds 27 degrees, the consumption of the polymerization inhibitor TBC increases significantly, leading to the formation of polymers ； One thermometer each at the top, middle, and bottom is sufficient; when there is no circulation, there should be a noticeable temperature difference!
2. This mainly involves carbon steel tanks; the impact of the small amount of impurities present in butadiene on downstream industries varies depending on the specific operating conditions； In the traditional carboxybutyl styrene industry, where the polymerization temperature is high, small amounts of rust or water impurities have virtually no effect on it ； For applications with slightly higher requirements, such as in the traditional styrene-butadiene and nitrile rubber industries, butadiene must be treated with alkali and water washing before it can be used ； Industries that require higher-quality styrene-butadiene rubber, such as this one, need to dry the butadiene before using it ；
The last edit to this post was made by Memories of Tomorrow on 2020-3-25 at 12:12. It seems that most butadiene storage tanks are made of carbon steel; according to corrosion data sheets, butadiene does not have strong corrosive properties
Thank you for the advice and information sharing! Circulating cooling should be necessary. I have two more questions: 1. If the butadiene sphere tank is fed using top spraying, will it have an impact on pressure fluctuations inside the tank? What type of spraying device is generally used for top spray feeding? I’ve seen information suggesting that feeding from the bottom using nozzles can improve heat exchange of the material inside the tank; is it feasible to use a pipe inserted from the top for submersed feeding? 2. How significant is the impact of rust content on the polymerization of butadiene inside butadiene spherical tanks? Could it cause dimerization of butadiene in the spherical tank, or is its impact negligible in actual production, with the effect of rust being ignored? :)
The explanation is very detailed! Like it – I’ve learned something new, and it should be very helpful for other sailors who don’t know much about this topic:handshake
1. It has a very minimal impact on pressure; the upper half is equipped with ring-shaped spray nozzles； Submersed insertion will not be able to resolve the issue of high temperature in the gas phase at the top in the future ； In the future, this will lead to a higher vapor temperature at the top of the tank, making it relatively easier for polymers to cause blockages in the vapor lines. 2. A high rust content in the liquid phase is usually continuously removed along with the output, having little impact on the liquid phase (unless the content of anti-polymerization agents in the raw material is low) ； It has a greater impact on gas-phase pipelines (especially the blind areas of some pipelines)
Sorry, is it usually not half?； Additionally, since the temperature at the top of buried tanks is controllable, feed can be introduced by circulating liquid beneath them
Thank you for the answer! The gas phase temperature was indeed not taken into account; would using nitrogen purging help to prevent blockages? If a ring pipe structure is used at the top, the support for that ring pipe also needs to be taken into consideration. For large spherical tanks, precise horizontal alignment of the supporting elements may be required during on-site welding; would it be possible to send some pictures of the local ring pipe design and its supports so that I can study them? I haven’t seen this structure before. I wonder if it would be feasible to use the liquid-level lowering method of large storage tank foam fire tanks? It seems that the ring-type heat exchanger doesn’t offer as good performance:)