Problem of easy vacuum formation when starting a constant-bottom pump
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This post was last edited by fye002 on 2011-6-9 at 23:04. When the atmospheric pressure tower bottom pump is started up, cavitation can occur, causing the tower to become full; as a result, it becomes very difficult to transport the oil from the bottom of the tower, which may lead to the shutdown of the facility – a very troublesome situation. Do any of you have any good experiences that can help prevent or reduce such issues, or any effective methods for dealing with them? Please share your ideas!
Before starting the pump, try to remove all residual water and gas from the pipelines. Additionally, avoid temperatures at which vacuum formation is likely to occur during the heating process, and activate the electrodesalination tank in a timely manner to enhance desalination and dehydration…
The key during the startup process is to remove water effectively and to get through the dehydration phase quickly in order to avoid pump cavitation; proper dehydration through a cold-cycle process is necessary, and the constant temperature of 150 degrees should be maintained for a sufficient duration to evaporate the water contained in the crude oil； Between 180-280 degrees, the temperature should be raised rapidly to pass through the evacuation period (at this temperature range, the water contained in the oil is at its evaporation temperature, making it easy for vaporization to occur and lead to pump evacuation); generally, the constant-temperature phase at 250 degrees should not be extended compared to a constant-temperature phase of 150 degrees or 300 degrees ； By enhancing systematic dehydration, evaporating water at low temperatures, and rapidly passing through the evacuation phase, the pump essentially does not experience evacuation during the startup process of the device
It is likely due to insufficient dehydration; therefore, the constant-temperature dehydration process should be prolonged as much as possible to ensure thorough dehydration. Once all the moisture has been removed, vacuuming should not occur.
Do these temperature ranges refer to the bottom temperature of the tower? Or the furnace outlet temperature? Shouldn’t a closed-loop system make it easier to remove all the water from the system?
During constant-temperature dehydration, intensify the dehydration process and switch to the backup pump in a timely manner to prevent water from the backup pump from entering the tower and causing vacuum.
The key is to remove water and quickly pass through the dehydration phase; it is necessary to switch to the backup pump in a timely manner to prevent the backup pump from carrying water.
The key is to remove water from the system and to quickly get past the dehydration phase in order to prevent the pumps from running dry; it’s also necessary to switch to a backup pump promptly. Generally, for a temperature of 250 degrees, it’s not advisable to extend the heating period at 150 degrees or at 300 degrees
2.1 is the guarantee for cyclic constant temperature time； Second, establish a mechanism to prevent water from entering the tower during reflux.
Reply to 3# linweihua6: Generally, for a constant temperature of 250 degrees, it’s not necessary to add an additional 150-degree constant temperature phase or a 300-degree constant temperature phase. I’m wondering – the statement you made seems a bit difficult to understand. Could you please explain it in more detail? Thank you
A constant temperature of 250 degrees is not required; instead, extend the constant temperature period by 150 degrees at the beginning of operation and by 300 degrees as well； By enhancing systematic dehydration, evaporating water at low temperatures, and rapidly passing through the evacuation phase, the pump essentially does not experience evacuation during the startup process of the device