Lauber-EnergieNutzZentrale

A versatile bulk material drying system combined with intelligent heat utilisation

he L-ENZ serves, in combination with special ventilated hook-lift / roll-off containers or static drying bays, as an efficient and powerful system for drying bulk solids such as sawdust, wood chips, chopped wood (firewood), grain, maize, hay and biowaste such as digestate. The drying system is delivered ready for connection, including an integrated technical room and a flexible control system. High-quality components such as radial fan, frequency converters and heating technology are fully installed and ready for operation.

The warm air generated by the L-ENZ is forced through flexible air ducting or insulated air ducts into the ventilation system and flows through the bulk material.

The entire system is versatile and individually adaptable to on-site conditions, offers flexible connection options and is modular and expandable. With the LAUBER L-ENZ, you receive a low-maintenance and highly efficient complete solution from a single supplier. From the clarification of the hydraulic integration into your heating network to the selection of the suitable drying container, the LAUBER team advises and supplies you in a reliable and professional manner.

Optimised for all common heat sources

The L-ENZ can utilise warm water-based heat from

• biogas plants
• biomass boilers
• wood gasification plants
• biomass combined heat and power plants
• carbonisation plants
• and others.

Thanks to the fully automatic control system of the L-ENZ, the dryer can be used as a heat sink for the heating network, while other heat consumers (such as a district heating network) are always given priority.

CHP plants are reliably cooled – excess heat is not discharged unused via emergency coolers.

The L-ENZ drying system is a fully EEG-compliant solution for the economical and effective utilisation of excess heat and is compatible with energy incentive schemes such as the UK Renewable Heat Incentive (RHI).

The L-ENZ drying system is available either with a weather-proof housing for outdoor installation or alternatively as a steel frame design without housing.

Fresh air is drawn in via a weather protection grid with filter fleece by means of a high-performance radial fan and forced through the water-to-air heat exchanger.

The special fan design allows higher pressure levels at lower electrical power consumption compared to freely rotating radial fans, which are often installed in other drying systems.

The system is pressure-optimised on both the water and air sides, thus ensuring the lowest possible operating costs. On average, only 1–3% electrical energy is required to utilise 100% thermal energy. For example, when utilising 300 kWh/h of thermal energy, the L-ENZ dryer operates with only 3 to a maximum of 9 kWh/h of electrical power consumption, depending on the material being dried and the water flow and air inlet temperature.

The heated air is supplied via flexible air ducting and insulated air ducts into various types of drying containers such as hook-lift drying containers or stationary drying boxes, which are equipped with appropriate ventilation floors.

By means of individually adjustable air shut-off dampers, the air is distributed automatically according to defined parameters or manually. The air outlet side of the L-ENZ (ducting, containers, etc.) can be extended individually at a later stage.

The L-ENZ continuously generates high air outlet temperatures close to the available hot water flow temperature of the heating system. High air outlet temperatures are a key requirement for efficient drying, as air temperature has a decisive influence on moisture absorption capacity and therefore on drying time.

The optimal hydraulic integration into your heating network

Efficient heat utilisation and drying start with the correct hydraulic integration of the drying system.

We explain why integration into the system return line is fundamentally incorrect and why a costly system separation is not required for the safe operation of an L-ENZ dryer.

The L-ENZ is supplied with a complete heating package, including water flow control individually designed for the on-site heating network. Thanks to its high flexibility, the L-ENZ can be easily integrated into an existing district heating pipeline or connected directly to a buffer tank.

The L-ENZ control system regulates not only the fan operation but also the hot water supply according to various control strategies. In addition to buffer tank monitoring, this ensures reliable operation even with strongly fluctuating heat availability throughout the year.

Utilisation of up to 1.4 MW heat with one system

The L-ENZ is available in nine different standard sizes. The number of containers that can be ventilated simultaneously depends on the available heat output, the desired air outlet temperature and the type of bulk material.

We also realise larger-scale projects, for example systems in which two or more L-ENZ units are controlled by a single control system.

Extensive and versatile accessories on the air outlet side

The L-ENZ can be combined with a wide range of different drying containers.

Individually designed and insulated air ducts as well as flexible air ducting are used to connect the L-ENZ to the drying containers. The air ducts are aerodynamically optimised, reduce ongoing electricity costs and, due to lower pressure losses, allow higher heat utilisation compared to (excessively) long flexible ducting.

All duct components offer high continuous pressure resistance and are suitable for air temperatures well above 110°C.

Depending on on-site requirements and logistical conditions, bulk materials can, for example, be dried in

• LAUBER TroCo hook-lift drying containers with universal ventilated floors
• LAUBER heavy-duty ventilated drying floor for building stationary drying bays (front-loader filling)
• LAUBER drying tables for hay bales
• as well as third-party systems such as walking floor dryers or self-built drying containers or trailers.

The modular system design allows individual expansion and capacity increase at any time.

With the L-ENZ, you can economically and gently dry virtually all air-permeable bulk materials, including for example:

• Wood chips for the provision as a storable renewable substitute fuel
• Logs / firewood to increase calorific value
• Corn/maize and grain to achieve storability and reduce transport costs
• Seeds / herbs / hemp plants for seed increase and for the pharmaceutical industry
• Biowaste such as horse manure (as bedding for cows) or the sieve discharge from waste management companies
• Animal feed such as crushed sugar beet as a rot-free feed supplement
• Substitute fuels from waste with high moisture content to reduce transport volume and costs

As standard, the control system of the L-ENZ includes dedicated functions for the gentle drying of temperature-sensitive materials. Alfalfa, which forms the basis for the production of high-quality hay milk, retains its valuable nutrients thanks to controlled drying with the L-ENZ. Seeds maintain their germination capability.

Efficient and fully automatic operation thanks to intelligent control

A machine is only as economical as its operation allows. An intelligent control is an essential requirement for the efficiency, operational safety and ease of use of a drying plant.

Therefore, the touch panel control builds an essential part of every L-ENZ dryer. It monitors all operating parameters and controls all actuators. From the water supply to the air volume generation and distribution, the L-ENZ control system controls both the heat consumption and the entire drying process.

Individual extensions also allow the monitoring of external equipment such as a buffer storage and provide features such as the active grain cooling after drying.

Benefit from our experience!

Today, more than 1,300 L-ENZ systems are in operation worldwide.

The portfolio of completed projects ranges from an L-ENZ 80 with a 20 m² drying box connected to a 75 kW biogas plant to an L-ENZ 1250 with a 60-metre air duct and 24 simultaneously ventilated hook-lift drying containers at a biomass combined heat and power plant.

Whether as the sole heat consumer connected to a biomass boiler or as an energy utilisation centre with buffer tank control and fully automatic air damper control based on material temperature or combined with vehicle load cells – the L-ENZ is a central all-in-one technical solution, combining heating network monitoring, economical heat utilisation and efficient drying in one system.

In operation worldwide

Numerous customers outside Europe appreciate the experience of LAUBER.

Whether a research centre in Canada, a veneer plant in Ivory Coast or a local power generator in Japan, companies worldwide rely on the reliability of the L-ENZ.

For overseas projects, LAUBER offers the L-ENZ in a special design installed in an intermodal shipping container. Containers or trailers sourced locally can be cost-effectively equipped with LAUBER ventilation components and used for drying.

If required by regulations in the destination country, we offer project-specific machine inspections and certifications carried out by authorised testing bodies.

Operation with alternative heat transfer media – it does not always have to be water

Your heating network works on thermal oil basis with high flow temperature?
You have large amounts of heat available in the form of steam and you want to dry bulk solids?
In times of low feed-in tariffs, you would like to use a part of your photovoltaic energy for drying high-quality seeds?

Then please contact us! We will be pleased to offer the proven L-ENZ technology in combination with alternative heat transfer media, tailored to your specific application.