Sight window for a silo and bulk-material vessel
Level and bridging observation without excess pressure; dusting and cleaning.
On silos a window is needed to control the product level, bridging and the filling boundary. There is no pressure, but there is dust and sticking.
Glass fouling is the main problem of this application: a window without a wiper quickly becomes useless.
Typical conditions
- no excess pressure or vacuum;
- heavy dusting at loading;
- abrasive products;
- ambient temperatures and solar heating.
What visibility is required
The lower filling boundary and the possible bridge zone. Often two windows at different heights or an oblong window along the axis are installed.
Limits
- abrasive dust — resistance of glass and wiper;
- non-pressure windows are not allowed where pressure appears;
- safe access for servicing windows at height.
Questions for the vessel designer
- is the absence of pressure guaranteed at pneumatic loading?
- which dust is expected and how abrasive is it?
- how are windows at height serviced?
Which classes to consider
Non-pressure constructions with a wiper; for pneumatic conveying with pressure — pressure fittings per calculation.