External gas tank

Externer Biogasspeicher inkl. techn. Komponenten

External gas tanks offer additional gas storage capacity in order to compensate for production fluctuations, consumption fluctuations, volume changes due to variations in temperature and consumer devices becoming idle, as well as to store already produced gas for future use.

  • Gas storage volumes up to 5,000 m³
  • Gas operating pressures between 20 and 35 mbar



Anchoring the gas tank:
The gas tank is anchored to the concrete floor slab using attachment rings made out of stainless steel (inner membrane, outer membrane). No components need to be embedded into the floor slab during its manufacture.

Technical features:
A continuously operating fan constantly keeps the outer shell under pressure. ATEX-certified construction and spark-proof housing. Steel structure with high-quality protective epoxy coating.

Filling level gauge:
An ultrasound probe enables the level of the stored gas to be gauged by measuring the deflection of the membrane, thus allowing efficient determination of total volume.

Hydraulic guard:
This protects the gas container against excess pressure. Its switch-off pressure is set to a fixed value. The hydraulic guard must be present in order to ensure the safety of the gas container. Material: stainless steel (316).

Regulating damper:
An adjustable damper enables a constant pressure to be maintained in the outer shell. It operates according to the following principle:

  • The damper is opened to maintain a specified pressure in the outer shell (a reminder: the air supply runs constantly).
  • When the pressure in the outer shell drops (which is the case when the gas container is being emptied), the damper reduces the area of the opening.
  • When the pressure in the outer shell rises (which is the case when the gas container is being filled), the damper enlarges the area of the opening.
  • The damper is fitted with a balancing system in order to maintain a defined pressure in the outer shell. Material: stainless steel (304).

Gas pressure sensor:
We offer a pressure transducer that can be fitted to the gas pipes close to the gas storage tank. It is suitable for use in explosive atmospheres (ATEX II 1/2G EEx ia IIC T6) and is calibrated for 0–30 or 50 mbar.

Biogas outlet monitor:
The damper can optionally be fitted with a CH4 detector. This measures the gas concentration in the atmosphere between the membranes. It is positioned at the entrance to the damper, i.e. at the point where the air circulating between the membranes has to flow through. It ensures that the inner membrane is constantly checked for leaks by measuring the CH4 content of the sediment, as a percentage. If the gas is detected, this device enables a safety procedure to be initiated in real time, for example stopping the supply of gas and discharging stored gas to the safety flare stack.