The TB-DV series.

Dehumidifier with valves for indoor & outdoor use

GIEBEL Adsorber® of the TB-DV series are disposable dehumidifiers especially for transformers. They are suitable for indoor and outdoor use.
The plastic housing is filled with GIEBEL Xdry®. The desiccant mixture ensures effective drying of the supply air. In addition, the dehumidifiers have a stable valve part made of fiberglass-reinforced polyamide and an oil reservoir. When the adsorber is saturated, the cartridge can be unscrewed and replaced.
The suspended version is available with all common connections for transformers. The series has an activated carbon layer to separate escaping oil mist. This ensures cyclic self-regeneration and thus very long maintenance intervals.

Mode of operation.

Adsorption – drying of the supply air

  • The filling level of the system decreases

  • Humid air is sucked in

  • Valves open at approx. 6 mbar

  • Uniform flow through the adsorber

  • Air is dried to 2% rH

  • GIEBEL Xdry® discolors as saturation increases

  • Air is filtered to 2μm


Dry and clean supply air


Desorption – separation of oil particles

  • The filling level of the system increases

  • Dry, oily air is squeezed out

  • Activated carbon absorbs the oil mist

  • Dry, oil-free air regenerates the desiccant

  • GIEBEL Xdry® partially recovers its color


Self-regeneration and oil-free exhaust air

Technical data.


The sucked-in air opens the valves in the lower part of the adsorber already at approx. 6 mbar. After flowing into the adsorber, the air is evenly distributed over the cross-section. The pre-filter disc frees the air from coarse dirt particles.

When flowing through the desiccant, the water molecules are reliably removed from the air. The gap volume of the granulate is optimally selected with 2 to 5 mm grain size and guarantees a minimum pressure build-up with very good drying efficiency at the same time. Thus, a residual air humidity of max. 2 % rH and a dew point of -40 °C are achieved at the beginning of the drying process. A 2 µm particle filter ensures that all dirt particles are separated from the ambient air and the GIEBEL Xdry® fill and that the connected plant is not contaminated.

When air is discharged, the 2µm particle filter and a layer of activated carbon prevent oil particles and oil mist from entering the desiccant, thus enabling the adsorber to self-regenerate.

As saturation increases, the orange silica gel grains of the GIEBEL Xdry ® fill turn green. If the silica gel grains have turned completely green, the adsorber must be replaced.

Pressure ratios.

Replacement cartridges.

We have developed replacement cartridges for the TB-DV series. To do this, open the locking clips and attach the new cartridge. Unscrew the valve part from the old cartridge and screw it onto the new one.

Adsorber Replacement cartridge