Viscous fluid reaction apparatus

A viscous fluid reaction apparatus, comprising:

• a glass reaction vessel comprising an inlet, an outlet, and a stirrer opening;
• a gas-tight inlet assembly disposed in the inlet;
• and
• a gas-tight stirrer assembly, a portion of which is disposed in the stirrer opening, the gas-tight stirrer assembly comprising:
• a stirrer opening adapter disposed in and configured to interface with the stirrer opening,
• a stirrer coupling comprising a stirrer shaft seal connected to the stirrer opening adapter,
• a stirrer shaft comprising one or more stirrer blades located at a blade end of the stirrer shaft,
• a motor coupling connected to the stirrer shaft, and
• a motor connected to the motor coupling,
• wherein the stirrer shaft passes through the stirrer coupling and the stirrer opening adapter such that the stirrer blade(s) are disposed in the glass reaction vessel at a blade height and the stirrer shaft is configured to rotate about a stirrer shaft axis being driven by the motor without compromising a gas-tight seal formed by the stirrer shaft seal,
• wherein the stirrer coupling defines an annular space about a portion of the stirrer shaft proximal to a coupling end of the stirrer shaft, wherein the annular space comprises an annular space seal comprising one or more perfluoroeslatomer O-rings that is gas-tight and allows the stirrer shaft to rotate, and
• wherein the stirrer coupling further comprises a purge gas inlet configured to provide a purge gas to the annular space.