Practical Exercise on Purification Technology Version [023]
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This post was last edited by hai8487 on 2017-8-2 09:55. Most pumps are equipped with a minimum return line – what is its purpose? Answer: Three points: 1) When a centrifugal pump operates at low flow rates, fluid separation can occur inside the pump, which can lead to vibration and noise. By setting a minimum return line, it is ensured that a certain amount of fluid flows through the pump at all times after it starts up, thereby preventing cavitation. 2) When a centrifugal pump with high power operates with the outlet valve closed, the fluid inside the pump becomes increasingly hot; in severe cases, this can damage the bearings. By installing a minimum flow line, it is possible to ensure that a certain amount of fluid flows through the pump at all times while it is operating, thereby preventing such issues from occurring ； 3) When operating at low flow rates, the pump shaft is subject to additional radial forces. By installing a minimum flow line, it is ensured that a certain amount of fluid flows through the pump at all times during operation, thereby preventing the pump shaft from being subjected to excessive radial forces. Coalification Region Purification Technology Edition – 2017 Coal Chemical Industry “My Technical Upgrades” Contest (Generous Prizes Available) http://bbs.hcbbs.com/thread-1786290-1-1.html Registration for Chemical Engineers – Experience Sharing Event “Learning from Others’ Experiences” http://bbs.hcbbs.com/thread-1808158-1-1.html
Prevent cavitation, protect the pump, and safeguard the mechanical seal.
1) When a centrifugal pump operates at low flow rates, fluid separation can occur inside the pump, which can easily lead to vibration and noise. By setting a minimum return line, it is ensured that a certain amount of fluid flows through the pump at all times after it starts up, thereby preventing cavitation. 2) When a centrifugal pump with high power operates with the outlet valve closed, the fluid inside the pump becomes increasingly hot; in severe cases, this can damage the bearings. By installing a minimum flow line, it is possible to ensure that a certain amount of fluid flows through the pump at all times while it is operating, thereby preventing such issues from occurring ； 3) When operating at low flow rates, the pump shaft is subject to additional radial forces. By installing a minimum flow line, it is ensured that a certain amount of fluid flows through the pump at all times during operation, thereby preventing the pump shaft from being subjected to excessive radial forces.
1) When a centrifugal pump operates at low flow rates, fluid separation can occur inside the pump, which can easily lead to vibration and noise. By setting a minimum return line, it is ensured that a certain amount of fluid flows through the pump at all times after it starts up, thereby preventing cavitation. 2) When a centrifugal pump with high power operates with the outlet valve closed, the fluid inside the pump becomes increasingly hot; in severe cases, this can damage the bearings. By installing a minimum flow line, it is possible to ensure that a certain amount of fluid flows through the pump at all times while it is operating, thereby preventing such issues from occurring ； 3) When operating at low flow rates, the pump shaft is subject to additional radial forces. By installing a minimum flow line, it ensures that a certain amount of fluid flows through the pump at all times during operation, thereby preventing the pump shaft from being subjected to excessive radial forces
Its function is to protect the pump in case the pump outlet valve is not open.
Generally, only the minimum flow rate of the pump is specified to prevent it from operating at low load for extended periods, which could lead to overheating and increased wear, especially in pumps of types such as shielded pumps
Protects the pump from damage when the pump outlet valve is not open
1) When a centrifugal pump operates at low flow rates, fluid separation can occur inside the pump, which can easily lead to vibration and noise. By setting a minimum return line, it is ensured that a certain amount of fluid flows through the pump at all times after it starts up, thereby preventing cavitation ； 2) When a centrifugal pump with high power operates with the outlet valve closed, the fluid inside the pump becomes increasingly hot; in severe cases, this can damage the bearings. By installing a minimum flow line, it is possible to ensure that a certain amount of fluid flows through the pump at all times while it is operating, thereby preventing such issues from occurring ； 3) When operating at low flow rates, the pump shaft is subject to additional radial forces. By installing a minimum flow line, it is ensured that a certain amount of fluid flows through the pump at all times during operation, thereby preventing the pump shaft from being subjected to excessive radial forces.
The pump’s return line serves two purposes: it can act as a minimum return line, providing protection for the pump when the user flow is less than 30% of the pump’s rated flow； Secondly, it facilitates the flow of materials within the storage tank, preventing the formation of dead zones in certain areas of the tank where the materials might aggregate, settle, or deteriorate.
1) When a centrifugal pump operates at low flow rates, fluid separation can occur inside the pump, which can easily lead to vibration and noise. By setting a minimum return line, it is ensured that a certain amount of fluid flows through the pump at all times after it starts up, thereby preventing cavitation. 2) When a centrifugal pump with high power operates with the outlet valve closed, the fluid inside the pump becomes increasingly hot; in severe cases, this can damage the bearings. By installing a minimum flow line, it is possible to ensure that a certain amount of fluid flows through the pump at all times while it is operating, thereby preventing such issues from occurring ； 3) When operating at low flow rates, the pump shaft is subject to additional radial forces. By installing a minimum flow line, it is ensured that a certain amount of fluid flows through the pump at all times during operation, thereby preventing the pump shaft from being subjected to excessive radial forces.
1) When a centrifugal pump operates at low flow rates, fluid separation can occur inside the pump, which can easily lead to vibration and noise. By setting a minimum return line, it is ensured that a certain amount of fluid flows through the pump at all times after it starts up, thereby preventing cavitation. 2) When a centrifugal pump with high power operates with the outlet valve closed, the fluid inside the pump becomes increasingly hot; in severe cases, this can damage the bearings. By installing a minimum flow line, it is possible to ensure that a certain amount of fluid flows through the pump at all times while it is operating, thereby preventing such issues from occurring ； 3) When operating at low flow rates, the pump shaft is subject to additional radial forces. By installing a minimum flow line, it is ensured that a certain amount of fluid flows through the pump at all times during operation, thereby preventing the pump shaft from being subjected to excessive radial forces.