Company: Our Innovations

Innovations by TLT-Turbo

Our mission to expand the position of TLT-Turbo GmbH being one of the world’s leading manufacturers of technology-driven industrial fans and ventilation systems, requires permanent adjustment and enhancement of the utilized technologies.

Our products must guarantee reliable and trouble-free operation for decades even under extreme conditions.

Increasingly complex market demands on systems and products, for instance in aerodynamics, acoustics, wear resistance, drive and automation engineering, and low energy and life-cycle costs, require customized solutions.

We meet these global challenges with the high flexibility and innovative drive of our employees in cooperative partnership with our customers. For special problems and questions we also collaborate closely and regularly with recognized research facilities.

Here are just a few examples representing the multitude of TLT’s innovative, successful solutions:

Innovations by TLT-Turbo
High-temperature Exhaust Fans With Adjustable Blades for Tunnel Ventilation With Additional Extreme Stability Requirements
In 2013, amongst other things, we supplied special exhaust fans with a diameter of nearly 3 m and a power consumption of 2.3 MW for the new Gotthard Base Tunnel in Switzerland.

As part of hot-gas tests at a certified testing laboratory, it could be proven that the requirement of the European standard EN 12101, a safe fan operation with external forced air cooling of the drive motor at 400°C over a two-hour period, is met. Furthermore, even if the forced air cooling fails, the fan can be operated for additional 90 minutes, this means much longer than required by other projects.

It is also worth highlighting that the structure of the fan components for alternating pressure shocks of up to +/- 10,000 Pa due to train movement must be designed to be safe in the long run.

A special TLT design of the fan components meets these extreme requirements.

Fans With Particularly Low Noise Level
In 2010, we supplied the by far quietest fan of its performance class (3500 kW) and diameter range (4.7 m) for the currently most powerful aero-acoustic wind tunnel worldwide in Braunschweig, Germany, called DNW-NWB being operated in the DNW foundation.

In order to reduce the noise of new airliners, as planned, by 50% up to the year 2020, the sound engineering of the NWB wind tunnel was reconstructed to the currently feasible lowest sound level in a far-reaching and innovative fashion.

The basic prerequisite to comply with the noise specifications of the NWB wind tunnel was to reduce the sound level of the main sound source, namely that of the wind tunnel fan.

Given decades of TLT experience in measuring and calculating the fan sound and in calculating, designing and producing silencers for fans and appropriate flow controls and in close cooperation with leading research institutes of DNW and DLR, we could significantly reduce the acoustic emissions of those large fans.

Through a giant leap forward TLT-Turbo GmbH succeeded in reducing the sound level of the NWB fan by more than 10 dB(A) compared to previous designs.

The knowledge gained from this project and the crucial aero-acoustic measures have been integrated in the design of TLT axial flow fans since then.

Cryogenic Wind Tunnel Fan
In 1994, we supplied a two-stage fan with variable speed drive, a maximum power consumption of 65,000 kW and a diameter of about 4.5 m for the European Transsonic Wind Tunnel (ETW) in Cologne, Germany. This wind tunnel is used to measure the aerodynamic quality of scaled aircraft models of international aircraft manufacturers with highest precision reaching the supersonic range.

During operation the main fan components, including a special silencer in the fan diffuser, have to regularly resist a temperature change between +40°C and approx. -190°C as well as simultaneous low-pressure or up to 4.5 bar (abs.) of overpressure.

These extraordinary demands required the application of a highest quality carbon fibre construction for the blades and special cryogenic steel for rotors and housings.

To date the highly stressed fan of the ETW regularly operates to the customer’s utmost satisfaction in this worldwide leading cryogenic wind tunnel.

Based on this experience, we are enhancing the fibre composite technology for the lightweight construction of our blades and over recent years we have successfully implemented this technology for highly dynamic fans with diameters of over 6 m in the sector of Formula 1 and motor vehicle wind tunnels.

TLT Oil Supply Units With Redundant Proportional Valve Control
The axial flow fans of TLT-Turbo GmbH are also used in macro-economically vital industry processes (e.g. power plants, refineries, tunnels etc.).The failure of a fan often also results in a significant reduction in operation or even in a failure of the whole system.

As the “availability” of a plant in recent years has become an issue of growing importance for technical and economical reasons, the TLT development of “redundant proportional valve control” has significantly increased in particular the availability of “blade adjustment”.

The option of “redundant proportional valve control” being available for the TLT oil supply unit twice comprises the control element of the blade adjustment unit. TLT-Turbo GmbH has been granted a patent for it.

Thus, the failure of a proportional valve does no longer come along with a contemporaneous failure of the blade adjustment unit. By switching over to the second, redundant hydraulic circle, the fan remains in the normal operation mode and the whole system remains available without restrictions.

Furthermore, it is also possible to upgrade fans of previous series with the innovative “redundant proportional valve control”. It is not necessary to modify the existing fan.

Professional Articles

Advanced Anti-abrasive Fan Coatings

by Dr.-Ing. Dieter Holzdeppe, Sabine Groh, Christopher Dahler
(PDF, 732 kB)

Particle Flow Erosion at Ventilator Components

by Dr.-Ing. Dieter Holzdeppe
(PDF, 3.7 MB)

Structural Statics and Dynamics on Axial Fan Blades

by Thomas Neff and Andreas Lahm
(PDF, 2.4 MB)

Origin and Control of Noise

by Hermann Wellmer
(PDF, 259 kB)