【Q&A Question No. 093】2018.04.03
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【Q&A Question 093】April 3, 2018: Briefly explain the reasons for liquid presence in the circulating hydrogen stream and the hazards associated with this (in centrifugal pumps) Since liquids are incompressible, introducing a liquid into a compressor exerts a strong impact on the impeller and the casing, resulting in damage to them. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) Due to the limits on the number of posts in the “One Question per Day” section, “One Image per Day” has been moved to the registered devices section; you can access it through the directory I posted. For management purposes, if you need to access content from a few days ago, please go to the summary post below to enter the “My Registration Season” event – (Note: This event is currently underway in the Chemical Engineering section) https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=18978. Summary post of daily questions for the 2018 Chemical Engineering Technology Training section: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888971. Summary post of daily images for the 2018 Registered Equipment section: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888970. Summary post of Q&A questions for the 2018 Hydrogen Production and Hydrogenation Technology section: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888968. Summary post of daily questions for the 2018 LNG Technology Discussion section: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888973. Summary post of Q&A questions for 2017 (updates have started): https://bbs.hcbbs.com/thread-1657793-1-1.html. Summary post of daily questions for 2017 (updates have started): https://bbs.hcbbs.com/thread-1657794-1-1.html. Summary post of daily images for 2017: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1875160. List of daily questions for the 2017 LNG section: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1804162. Summary post of Q&A questions for 2016 (updates completed): https://bbs.hcbbs.com/thread-1597792-1-1.html
Since liquids are incompressible, introducing a liquid into a compressor exerts a strong impact on the impeller and the casing, resulting in damage to them.
1. Liquid slugging occurs, vibrations increase, causing damage to the bearings and seals； 2. Liquid enters the dry gas seal, damaging it ； 3. The load increases, leading to higher gas consumption and damage to the bearings and seals.
Since liquids are incompressible, introducing a liquid into a compressor exerts a strong impact on the impeller and the casing, resulting in damage to them. Liquid carried in the circulating hydrogen causes the circulating hydrogen compressor to smoke; in severe cases, it can lead to vibration of the compressor and forced shutdown, as well as an increase in system pressure.
Reason: The high liquid level is too high or the foam breaker is malfunctioning, causing the circulating hydrogen to contain oil； In units equipped with a circulating hydrogen desulfurization system, liquid carryover is caused by either an excessively high liquid level in the desulfurization tower or amine solution foaming due to hydrocarbons in the circulating hydrogen. Treatment: ① Increase the pressure relief valve from the hydrogen circulation machine inlet buffer tank to the cold low-pressure separator, and quickly adjust the liquid level in the inlet liquid separation tank to normal. ②Suspend the amine solution circulation in the cyclohydrogen desulfurization tower if necessary. Check whether the heat tracing steam at the inlet of the circulating hydrogen compressor is activated. After excluding the above factors, if the circulating hydrogen still contains liquid, the possibility of a failed defoamer screen should be considered; in emergency situations, shutdown procedures should be followed.
Primary function of recycled hydrogen: First, hydrogen is an essential reducing gas in the reforming process; second, it helps reduce energy consumption and operating costs by allowing the reuse of waste gases.
Answer: Since liquids are incompressible, introducing a liquid into a compressor exerts a strong impact on the impeller and the compressor casing, resulting in damage to them.
Liquids cannot be compressed; entering a press can cause cylinder collision, leading to severe leaks and explosions
Since liquids are incompressible, introducing a liquid into a compressor exerts a strong impact on the impeller and the casing, resulting in damage to them. Liquid carried in the circulating hydrogen causes the circulating hydrogen compressor to smoke; in severe cases, it can lead to vibration of the compressor and forced shutdown, as well as an increase in system pressure. When circulating hydrogen carries liquid, the following phenomena occur: ① The liquid level in the liquid separation tank at the inlet of the circulating hydrogen compressor is too high; when circulating hydrogen carries liquid, the flow rate of the circulating hydrogen compressor fluctuates, and in severe cases this can lead to vibration of the compressor and its shutdown due to failure. ②System pressure fluctuates. Reason: The high liquid level is too high or the foam breaker is malfunctioning, causing the circulating hydrogen to contain oil ； In units equipped with a circulating hydrogen desulfurization system, liquid carryover is caused by either an excessively high liquid level in the desulfurization tower or amine solution foaming due to hydrocarbons in the circulating hydrogen. Treatment: ① Increase the pressure relief valve from the hydrogen circulation machine inlet buffer tank to the cold low-pressure separator, and quickly adjust the liquid level in the inlet liquid separation tank to normal. ②Suspend the amine solution circulation in the cyclohydrogen desulfurization tower if necessary. Check whether the heat tracing steam at the inlet of the circulating hydrogen compressor is activated. After excluding the above factors, if the circulating hydrogen still contains liquid, the possibility of a failed defoamer screen should be considered; in emergency situations, shutdown procedures should be followed.
Since liquids are incompressible, introducing a liquid into a compressor exerts a strong impact on the impeller and the casing, resulting in damage to them. Liquid carried in the circulating hydrogen causes the circulating hydrogen compressor to smoke; in severe cases, it can lead to vibration of the compressor and forced shutdown, as well as an increase in system pressure. When circulating hydrogen carries liquid, the following phenomena occur: ① The liquid level in the liquid separation tank at the inlet of the circulating hydrogen compressor is too high; when circulating hydrogen carries liquid, the flow rate of the circulating hydrogen compressor fluctuates, and in severe cases this can lead to vibration of the compressor and its shutdown due to failure. ②System pressure fluctuates.
Since liquids are incompressible, introducing a liquid into a compressor exerts a strong impact on the impeller and the casing, resulting in damage to them.