Double membrane-gas storage on tanks
Tank covering with integrated gas storage for high pressures and large volumes
Outer shell protecting against climatic conditions – spherical or cylindrical
is external loads such as wind, snow and climatic conditions. With the help of clamping rails the outer and inner membranes are clamped to the tank in such a way that they are leak-proof and will never tear out.
The actual gas storage is located inside and thus protected against atmospheric conditions.
The SATTLER DMGS TM in spherical shape enables high pressures and large volumes.
The CENO DMGS TM in cylindrical shape (23° and 32°) enables a working pressure of up to 5 mbar and mean storage volumes.
Inner shell for gas storage
The inner membrane represents the gas-proof covering of the fermenter. The gas chamber is located between the inner membrane and the soil. The pressure within the support air space spreads to the biogas via the inner membrane. The inner membrane floats between the outer membrane and the brace system in different heights depending on the filling level.
The pressure in the gas chamber is limited by the overpressure valve.
Brace system
In case of excessive evacuation of the gas storage the brace system prevents the inner membrane from sinking down to the soil where it could be damaged by the mixers.
Measuring the filling level
The position of the inner membrane is measured by ultrasonic sensors or rope length measuring systems. These measured values can be transformed into filling level values and serve for the plant control.
Storage volume
The storage volume results from the tank diameter, its overall height and the shape of the storage.
Working pressure
The external shape and dimension of the storage have the greatest influence on the maximum working pressure of the storage. Spherical storage tanks are more suitable for higher working pressures than cylindrical tanks. The higher the working pressure, the higher the permissible wind speeds and snow loads. The pressure inside the gas system is limited by overpressure and low pressure safety valves.
Membrane material
Membranes are made of polyester fabrics which are PVC-coated on both sides. Different membrane types are used depending on static requirements, statutory provisions and customer requirements.