L-ENZ: Lauber dryer for bulk solids

Utilisation of water heat from biogas plants, biomass CHP plants, cogeneration units of heat and power, wood gasifiers

Lauber dryer L-ENZ for bulk solids serves in combination with special ventilated hook lift containers as an efficient and powerful system for drying bulk solids like e.g. wood chips and firewood, digestate, grain and maize.
Warm air produced by the Lauber dryer L-ENZ is pressed through flexible air tubes or insulated air channels to special ventilated hook lift containers. These containers are equipped with a ventilation bottom to allow the warm air to pass equally through the bulk solids from underneath.

When working with a higher quantity of containers simultaneously, the use of air channels (ventilation ducts) is recommended. Air channels are insulated and designed for low flow resistance to allow an optimized air distribution. The typical drying time for wood chips is approx. 2 days.
The drying containers are used both for transporting as well as housing in which the bulk solids will be dried. Thus the wood chips can be filled, dried and transported in the same container which saves time-consuming reloading.

The Lauber dryer L-ENZ comes completely assembled and ready for immediate operation.
The control room contains the flexible control system, high-quality components like radial fan, two frequency transformers (for fan as well as for the heating pump), heat exchanger as well as heating engineering.
In cases no housing is needed, all high-quality components are mounted on a steel frame and will be delivered as L-ENZ equipment without housing.

Besides using containers there are other possibilities!
Ventilation systems for trailers provided by customers or drying boxes for vehicular access can also be ventilated by a Lauber dryer L-ENZ. Aerodynamic devices in the bottom and air funnels provide an equal air distribution.

Wood chips as regenerated fuel can substitute the fossil and limited energy sources like oil, coil and gas. Wood chips as energy source help to reach a long-lasting, sustainable and crisis-free energy supply. The demand for dried wood chips will increase in future steadily.

Wood chips are in most cases cheaper than pellets and ensure as well a high operation safety of heating systems. For refurbishing wood from the forest and producing woodchips only low technical effort is needed.

To use dry wood chips in a burning process saves thermal energy!

Heizwert von Hackschnitzel

The usable heating energy (calorific value) of wood chips depends much more on the water content in the wood chips than on the species of wood. Fresh wood chips with a water content of 55 % (W55) provide approx. 2000 kWh in energy per ton. By drying the wood chips to 20 % water content (W20), the calorific value is virtually doubled and increased up to around 4000 kWh per ton.

Or in other words: in a burning process of one ton of dried wood chips approx. 400 l of heating oil can be substituted.


Source: „Doubling“ the forest – Increasing calorific value by drying wood chips in simple facilities; presentation of Prof. Dr.-Ing. Horst Kreimes at CARMEN congress “Alternative raw materials for biomass“ on Nov 7th, 2008.

getrocknete Hackschnitzel

Using a surplus of heat
Using water heat from biogas plants and CHPs or available surplus of heat during summer, a viable, economic and renewable energy yield is achieved. Furthermore the dryer L-ENZ for bulk solids can substitute in many cases the function of an emergency cooler.

Reduction of heat for energy networks at too high return temperature
Lauber dryer L-ENZ allows a moderation in heat extraction in situation of a varying energy demand. Energy demand can be regulated according to following different purposes: return temperature, pressure differential or manual working mode. According to a desired value of energy demand, the drying process of woodchips varies in longer or shorter drying times.

Several pictures of Lauber customers

Technical data

Technical data of Lauber dryers L-ENZ :

L-ENZ 80       3,0 kW electrical /     80 kW thermal » Connections for 2 containers
L-ENZ 150     5,5 kW electrical /     150 kW thermal » Connections for 2 containers
L-ENZ 280     7,5 kW electrical /     280 kW thermal » Connections for 4 containers
L-ENZ 370     11,0 kW electrical /    370 kW thermal » Connections for 4 containers
L-ENZ 650     18,5 kW electrical /    650 kW thermal » Connections for 6 containers
L-ENZ 800     30,0 kW electrical /    800 kW thermal » Connections for 8 containers
L-ENZ 1000   45,0 kW electrical /    1000 kW thermal » Connections for 10 containers

The values above are nominal values and depend on the environmental conditions.

By working with installed frequency transformers, electrical consumption is optimized. By drying wood chips from W50 to W20, electricity consumption is approx. 2-4 kWh / m³ wood chips. On average 1-3% electrical performance is needed to use 100% thermal heating.