Questions & Answers

Frequently asked questions

Please feel free to contact us if you have any questions or should you require technical advice and more detailed product information.
General Questions

What exactly is an Eckrohr (Corner Tube) Boiler?

An Eckrohr (corner tube) boiler is a natural circulation single drum water-tube boiler with its characteristic water-steam cycle and a pre-separation of the steam-water mixture occurs outside of the drum and in the unheated down comers. The Eckrohr Boiler is self-supporting and stands on its own down comers.

How many Eckrohr boilers exist?

More than 6100 around the world.

How many Eckrohr boilers exist which are fired on municipal waste?

More than 600 over the world especially in Japan and Germany.

Where can I buy an Eckrohr boiler?

Please refer to our list of licensees in the download section.

Can Eckrohr Boilers be designed and fired with multiple fuels?

Yes. The Eckrohr Boilers can be designed for multiple fuels firing as well. The Eckrohr Boilers are designed and used as Waste Heat Boilers too.

Is it also possible for ERK to design a Bi Drum Boiler?

Yes, ERK has also gathered noteworthy experience in designing of Bi Drum boilers. But, ERK Engineers prefer to have an Eckrohr boiler because this design has more technical and economical advantages than a Bi Drum boiler.

Does ERK Eckrohrkessel GmbH have any online Case studies, success stories?

Please refer to the files available in ‘’Downloads’’ section for the press releases and the case studies done by ERK Eckrohrkessel GmbH.

Does ERK Eckrohrkessel also manufacture Boilers?

No. ERK Eckrohrkessel GmbH is only an engineering consulting company. But with a renowned and worldwide experience with different Licensees, we obviously recommend manufacturers who have experience and expertise in manufacturing the Eckrohr Boilers.

Is it possible to visit an Eckrohr Boiler in operation with an ERK Engineering team?

Yes. Please stay updated with the news and events of ERK Eckrohrkessel GmbH in menu ABC. One can find the next visits to Eckrohr Boiler.

What can be an expected average life span of an Eckrohr Boiler?

The design of the boiler is according to the material strength for minimum 25 years with normal operation periods. Some boilers exist with operation time more than 40 years. Due to some corrosive fuels like for municipal waste reparations or changes of the corroded heating surfaces has to be done earlier.

License Related Questions

How can I get a licence?

Please contact us for a step by step and detailed process of signing an agreement.

Is it possible to place an order although I am not a Licensee of ERK?

Yes. It is possible to place an order for an Eckrohr Boiler. Apart from the Boiler ERK also offers Water Circulation calculations, Heat, Mass and Energy Transfer calculations, FEM and CFD calculations.

What are the exclusive services offered by ERK to the Licensees?

The Licensee receives the technical know how of ERK Boilers in detail and continuous support from the experienced engineers in the ERK Team. Apart from that ERK organises an official conference every two years where experiences, motives, interests and state of the art technology used by ERK is exchanged with the licensees.

Technical Questions

What are the different fuels which can be used to fire an Eckrohr Boiler?

Almost every fuel can be used to fire an Eckrohr Boiler. The fuels which are commonly used in the USA, Europe and Pacific Countries are:

Solid – Biomass like (Bagasse, Rice Husks), Coal, Industrial waste, Lignite,Organic matter, Rubber-wood, Scaly Bark, Solid waste, Sludge, Wood, Woodchips.

Liquid – Heavy oil, Light Oil, MFO (marine fuel oil), Oil.

Gas – Fuel gas, khuff gas, Natural Gas, Methane.

Are there any combustion technologies offered by ERK?

Yes but only combined with an ERK Eckrohr boiler design. ERK offers the combustion technology like, Fluidized Bed Combustion (FBC), the inclined water cooled grate, vibrating grate and Torsional Combustion Chamber (in coop with our Licensee Berkes from Uruguay). Any kind of waste heat and burners and grates can be used to fire an ERK Boiler.

What is included in basic engineering design for an Eckrohr Boiler?

Basic engineering within a project for a licensee

1. Heat transfer calculation for maximal load and one part load

2. General drawing: basic construction, schematic sketch with main Dimensions for price calculation

In case of an order

3. Update and optimization of thermal calculations (3 further load case)

4. Check-up water circulation

5. Tube-layout of boiler tube cage

What is the normal range of an Eckrohr Boiler in terms of thermal capacities?

ERK Eckrohr Boilers have been ranging from 0, 3 to 250 MWth

Advantages of Eckrohr Boiler

How compatible is an Eckrohr Boiler with respect to a burner and space available?

ERK boilers can be designed to for any combustion system available in the market, also the customizability for an ERK Boiler has a wide range it can be extended in horizontal and vertical direction both in case of limited space.

How fast the Boiler can be fired to full load capacity?

Eckrohr Boilers can be fired to full load capacity really fast and quickly. The drum in an Eckrohr boiler is smaller and hence the thickness of the drum is lower as compared to that of other boilers. The lower thickness is responsible for a higher rate of change of temperature. We claim to have the rate of change of temperature as of at minimum 2Kelvin/ min*.

How fast is the rate of change of steam load in an Eckrohr Boiler?

When operating on variable loads the Eckrohr Boiler needs very short time to cope up and operate at changing load while maintaining the same pressure. This is because the water level remains calm. Also the larger diameters of unheated down comers prevent the formation of steam bubbles at pressure fluctuations or higher change of steam load.
We claim that the rate of change of steam load is at (least) 20% per minute for an Eckrohr Boiler*.

How low is the rate of change of pressure in an Eckrohr Boiler?

The Eckrohr Boilers are capable to cope up with the change in pressure quickly without disturbing the water steam cycle in case of a sudden release of pressure. The diameter of vertically oriented downcomers (which also act as frame for support and makes ERK boiler selfsupporting) is relatively large which prevents the formation of steam bubbles at pressure fluctuations or higher rate of change of load.  We claim the rate of change of pressure is 0.5bar/min*.

What are the advantages of an Eckrohr Boiler over Bi Drum Boiler?

There are numerous advantages when comparing an Eckrohr Boiler to that of a Bi Drum boiler. Please download the file ‘Bi-Drum and ERK Boiler comparison’ from the link „Bi Drum and Eckrohr Boiler comparison’’ in the submenu Downloads for an overview. 

* subject to change in specific cases. Please contact us for further queries.