Sight glasses for visual control of digester. Photo: F.H. Papenmeier GmbH & Co. KG
Sight glasses for visual control of digester. Photo: F.H. Papenmeier GmbH & Co. KG

Sight glasses - visual control

Sight glasses allow an instant visual control of the anaerobic digester content. Forming of floating crusts, function of mixers or biological desulfurization can be easily inspected.


Sight glasses normally consist of a stainless steel frame with a rubber sealing and a special soda-lime glass according to DIN 8902. A wiper mechanism plus a spray-cleaning nozzle completes the sight glass.

 

The safety regulations for anaerobic digesters stipulated by professional farming associations require, amongst other things, that any sight glass fittings and electrically operated equipment attached to anaerobic digesters needs to be gas-tight and explosion-protected.

 

Sight glasses and ancillary equipment has therefore to be in accordance with ATEX 95 or comparing U.S. explosion protection standards. This is especially important when anaerobic digesters are run under thermophilic conditions.

 

The installation of two closely situated sight glasses allows the dazzle free vision into the digester.