25th October 2018
Our client needed a reliable solution for a polymerization process, in which a pump continuously circulates the polymer reactants through the reactor until the process is complete.
- During the reaction, the viscosity steadily rises from 25 to 18,000 mPas.
- After each batch, the system and pump must be cleaned in place with a flushing agent (1 mPas).
- The solvent is circulated using the same pump.
We opted for a stainless steel MAAG gear pump with heating jacket and double mechanical seal. The selected drive train enables the pump to run at low speed during the polymerization process, while allowing a much higher speed for the flushing cycle.
Moreover, the drive design takes account of the different torques needed for each step in the process, as well as during flushing. If necessary, the drive can even provide sufficient torque for a cold start with extremely viscous polymer (55,000 mPas).
The double mechanical seal is supplied with barrier fluid under pressure from a thermosyphon system equipped with cooling coil and level monitoring. The pressure vessel of the sealing system has sufficient capacity for the pump to run under normal operating conditions without a refill for at least 6 months. In that event, because the sealing system is also equipped with a manual filling pump, the barrier fluid can be replenished even while the system is running.
The drive geometry was chosen by the customer in advance. This meant that a compact and alignment-free construction on a pedestal was impractical, and the pump and its drive therefore needed to be built as a complete assembly on a skid frame. It was then logical to mount the sealing system on the same skid.
Pic1: Support foot and grout hole provide pump unit with additonal stability
Pic 2 Adjustment bolts for fine positioning of the pump unit
- Pump mounted on skid frame with adjusting screws for precise positioning
- Support foot to further stabilize the motor
- Integrated drip tray
- Integrated hoisting eyes to facilitate placement
- Grout holes enable the skid base to be filled with concrete for additional stability
Scope of supply:
Pump: MAAG stainless steel TX 110/110 THERMINOX®, with heating jacket and double mechanical seal
Sealing system: Aerni thermosyphon system with cooling coil, level monitoring and manual filling pump
Drive: Siemens e-motor with reduction gearbox