Gear pumps in polymerization

The prepolymer is the precursor of the actual polymer, which is usually a reactive oligomer. In terms of its consistency and properties, the prepolymer is still significantly more free-flowing, i.e. lower viscosity, than the end product itself. In the course of the polymerization process, the desired polymer is produced from the prepolymer. In the process, the melt passes through a number of different process stages and aggregates.

The prepolymer process stage

The prepolymer pump conveys the prepolymer from a light vacuum into the reactor. In this process stage, the polymer is produced from the pre-polymer melt.

The challenge: Depending on the plant requirements, a very wide control range for the volume flow must be covered by the pump. In addition, the pump is to be used in an ATEX zone, which means that increased safety must be ensured here as well.

Landscape

The characteristics of the pre-polymer pump

The prepolymer pump is a pump of the CHEM series. This is otherwise preferably used for low-viscosity media with poor lubricating properties. For safe and leak-free operation, this pump is equipped with a vacuum-tight shaft seal. As a rule, a threaded shaft seal with a buffered stuffing box is used. Because the CHEM series is extremely flexible, it can be equipped with a wide range of features.

For particularly demanding processes, a double flange seal with nitrogen overlay may also be necessary.

Design

Pump size
CHEM 3200-180-180
Throughput
6.000 up to 35.000 kg/h
Viscosity
up to 15 Pas
Temperature
275 - 290 °C
Pressure
up to 15 bar

Easy-to-maintain chemical pump for pre-polymer delivery

  • Gear pump CHEM
  • Moveable cart
  • Cardan shaft

  • Gear pump CHEM

    The CHEM series is an extremely flexible chemical pump. Depending on the application, different sizes, material combinations and sealing systems are available. Due to its high chemical resistance, the CHEM pump is particularly suitable for reliably conveying the low-viscosity prepolymer solution to the next process stage.

  • Moveable cart

    As a rule, the conditions in the plant are limited. For maintenance-friendly assembly and disassembly in the plant, the pump is installed on a spring-mounted, moveabile cart. The pump is decoupled from the drive unit and the reactor and can then be moved out from under the reactor to change wear parts or for maintenance. Disassembly is thus easily possible in the plant.

  • Cardan shaft

    A cardan shaft is used to transmit the power or torque from the drive unit to the pump. This can compensate for any height differences between the individual units and also absorbs thermal expansion.

Easy-to-maintain chemical pump for pre-polymer delivery