Sight window for a chemical reactor

A reactor is a classic place for a sight window: the operator needs to see the reaction course, foam, colour and the moment of crystallization or phase separation.

The window works at jacket pressure and temperature, often in an aggressive medium and with washing — this defines the fitting class and the materials of the pack.

Typical process conditions

• excess pressure and vacuum in different modes;
• working temperatures with peaks during steaming;
• aggressive media and solvents;
• mixing with foaming.

What visibility is required

Usually one or two circular DN 80–DN 150 windows with lighting are sufficient: light is critical in turbid media. Foam is better visible with a larger free diameter.

Limits and checks

• the medium-contact gasket follows the chemistry of the medium, the compensating one follows thermal cycles;
• thermal shock when charging a cold component;
• vacuum modes require separate confirmation;
• a wiper for polymerizing media.

Questions for the vessel designer

• which pressure and temperature modes does the jacket and the body allow?
• is vacuum present in the process and how deep?
• which documents are required for the fitting and the glass?
• where are the windows located relative to the mixer and the injection points?

Which classes to consider

For weld-in mounting — DIN 28120-type constructions; for existing flanges — DIN 28121 with a compatibility check. The final version is confirmed by the manufacturer with the complete data.