Selection of transfer pumps for high-temperature, high-viscosity materials.
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Our company has a magnetic gear pump that has recently been experiencing frequent bearing failures and demagnetization of the internal magnets. We are providing details about the operating conditions; we would like everyone to take a look and suggest ways to resolve this issue. Materials: A mixture of paraffin oil and liquid sodium (leakage must be prevented). Temperature: 230–270°C. Viscosity: Normally around 50 cts; it may reach 120 cts if the reaction does not proceed well. Pressure: Normally 0.3 MPa; it may reach 0.6 MPa if the reaction is poor. Head: Over 20 m. Flow rate: 10 m3/h. Air pumping may occur.
Is it because the material is quite viscous, which leads to poor internal circulation in the magnetic pump, inadequate lubrication of the rotor bearings, and wear of these bearings due to dry friction?
More or less, we analyze that there could be several reasons: first, high temperatures lead to a shorter service life of the bearings; second, poor material flow can cause damage to the bearings; third, it occurs when the pressure at the pump head exceeds the rated value. But there’s no solution.
The medium conditions are too harsh; the temperature is a bit high for magnetic pumps, and the viscosity is high, which certainly makes lubrication difficult. Could the ordinary centrifugal pump Plan32+53 solution be considered?
Perhaps there is an issue with your seal selection; use a gear pump designed specifically for high temperatures. The viscosity is 30 CST, which seems low; normal gear pump operation will be no problem
A high-temperature magnetic pump can be used; this viscosity can also be transported by a centrifugal pump, so an API-compliant magnetic centrifugal pump should be chosen.
Could you please send me some materials? Email: 15689851103@163.com
First, find a way to solve the issue of empty strikes. Idle running can easily cause bearing damage and demagnetization of the internal magnet
“...There are several reasons: first, the high temperature reduces the service life of the bearings; second, poor flow of the material can cause the bearings to be damaged due to dry running; third, it occurs when the pressure at the pump head exceeds its rated value... 1. A temperature of 250°C makes it easy for the internal magnets to lose their magnetism. 2. If there is dry running, it can easily lead to the vaporization of the medium, resulting in dry friction that damages the bearings； 3. If the outlet pressure of the gear pump exceeds the rated value, a safety valve can be installed in series with the outlet line; the discharge from this safety valve goes back to the inlet. 4. In addition to addressing issues such as dry running and overheating, it is also possible to choose a different type of pump, such as a single-screw pump equipped with a double-end face seal (options like Plan54~53a).
Thank you for your reply, but our materials are extremely dangerous and must not be leaked. Can a double-ended seal ensure no leakage?