【Q&A Question No. 094】2018.04.04
Thread Content
【Q&A Question 094】April 4, 2018: Briefly explain why, when releasing pressure after testing a tower, it is necessary to carry out venting from the top and draining condensate from the bottom at the same time. Towers are generally tested using steam; after testing, the pressure inside the tower is high. If only the drain for condensate at the bottom is opened during pressure release, the tray layers will be subjected to strong downward pressure, which can easily cause them to deform or even collapse. On the contrary, if venting occurs only at the top of the tower, the trays will be subjected to pressure from below, which causes them to deform and leads to floating valve stripping. If venting at the top is combined with condensate drainage at the bottom, the pressure on the trays can be **reduced; as a result, the trays do not deform and the accessories inside the tower are not damaged. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) Due to the limitations 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 ongoing in the Chemical Engineering section). https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=18978 For the daily questions section related to chemical engineering technology training in 2018: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888971 For the daily image section related to registered equipment in 2018: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888970 For the Q&A section related to hydrogen production and hydrogenation technologies in 2018: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888968 For the daily questions section related to LNG technology in 2018: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888973 For the Q&A section from 2017 (updates have started): https://bbs.hcbbs.com/thread-1657793-1-1.html For the daily questions section from 2017 (updates have started): https://bbs.hcbbs.com/thread-1657794-1-1.html For the daily image section from 2017: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1875160 For the list of daily questions related to LNG in 2017: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1804162 For the Q&A section from 2016 (updates are complete): https://bbs.hcbbs.com/thread-1597792-1-1.html
The tower is generally pressurized with steam; after pressurization, the pressure inside is high. When releasing this pressure, if only the bottom drain valve is opened, the tray will be subjected to strong downward pressure, which can easily cause it to deform
The tower is generally pressurized with steam; after pressurization, the pressure inside the tower is high. When releasing this pressure, if only the bottom drain valve is opened, the tray layers will be subjected to strong downward pressure, which can easily cause them to deform or even lead to the collapse of the tower. On the contrary, if only the top of the tower is vented, the trays will be subjected to a pressure difference from below, which again causes the trays to deform and the floating valves to be blown off. If venting at the top and draining condensate at the bottom are carried out simultaneously, the pressure exerted on the trays can be **reduced**, preventing the trays from deforming and avoiding damage to the accessories inside the tower.
If not done simultaneously, it prevents the tower from collapsing.
The tower is generally pressurized with steam; after pressurization, the pressure inside the tower is high. When releasing this pressure, if only the bottom drain valve is opened, the tray layers will be subjected to strong downward pressure, which can easily cause them to deform or even lead to the collapse of the tower. On the contrary, if only the top of the tower is vented, the trays will be subjected to pressure from below, which likewise causes the trays to deform and the floating valves to be blown off. If venting at the top and draining condensate at the bottom are carried out simultaneously, the pressure exerted on the trays can be **reduced; as a result, the trays will not deform and the accessories inside the tower will not get damaged
The tower is generally pressurized with steam; after pressurization, the pressure inside the tower is high. When releasing this pressure, if only the bottom drain valve is opened, the tray layers will be subjected to strong downward pressure, which can easily cause them to deform or even lead to the collapse of the tower. On the contrary, if only the top of the tower is vented, the trays will be subjected to pressure from below, which likewise causes the trays to deform and the floating valves to be blown off. If venting at the top and draining condensate at the bottom are carried out simultaneously, the pressure exerted on the trays can be **reduced; as a result, the trays will not deform and the accessories inside the tower will not get damaged
Drainage under pressure allows for more thorough removal of the liquid remaining in the tower
Prevent excessive upward or downward forces from causing damage to the internal components of the tower
The tower is generally pressurized with steam; after pressurization, the pressure inside the tower is high. When releasing this pressure, if only the bottom drain valve is opened, the tray layers will be subjected to strong downward pressure, which can easily cause them to deform or even lead to the collapse of the tower. On the contrary, if only the top of the tower is vented, the trays will be subjected to pressure from below, which likewise causes the trays to deform and the floating valves to be blown off. If venting at the top and draining condensate at the bottom are carried out simultaneously, the pressure exerted on the trays can be **reduced**, preventing the trays from deforming and avoiding damage to the accessories inside the tower.
Answer: The tower is generally pressurized with steam. After pressurization, the pressure inside is high; when releasing this pressure, if only the bottom drain valve is opened, the tray will be subjected to strong downward pressure, which can easily cause it to deform or even collapse. On the contrary, if venting occurs only at the top of the tower, the trays will be subjected to pressure from below, which causes them to deform and leads to floating valve stripping. If venting at the top is combined with condensate drainage at the bottom, the pressure on the trays can be **reduced; as a result, the trays do not deform and the accessories inside the tower are not damaged.
The tower is generally pressurized with steam; after pressurization, the pressure inside is high. When releasing this pressure, if only the bottom drain valve is opened, the tray will be subjected to strong downward pressure, which can easily cause it to deform or even collapse. On the contrary, if venting occurs only at the top of the tower, the trays will be subjected to pressure from below, which causes them to deform and leads to floating valve stripping. If venting at the top is combined with condensate drainage at the bottom, the pressure on the trays can be **reduced; as a result, the trays do not deform and the accessories inside the tower are not damaged.