A durable lightweight:
the charging racks made of Keramikblech®

Thin-walled frame con­struc­tions made of sheet ceramic, (Keramik­blech), have proven to be robust after more than 400 success­ful cycles. The material proper­ties, weight and mechan­i­cal strength were ex­pli­citly adapted to the extreme challenges at the site of appli­ca­tion.

Charging racks made of Keramik­blech offer special ad­van­tages for long-­term appli­ca­tions up to 1000 °C, not only due to their low thermal ex­pan­sion (approx. 50 % of steel), their thermal shock resist­ance, but also due to their stabil­ity and light­ness.

The material reli­abil­ity also enables ex­cellent service life. There are hardly any limits to the variety of shapes.


The homo­geneous bending strength level of iso­tropic CMC materials makes them suitable for multiple appli­cations.

Bending tests of iso­tropic and aniso­tropic CMC plates provide new view into the inter­action of fiber and matrix.

The samples of the material FW12 have been tested in 7 direc­tions: 0°, 15°, 30°, 45°, 60°, 75° and 90°. Sig­nif­i­cant dif­fe­rences in the bending behav­iour of iso­tropic and aniso­tropic material samples could be found:

Bending strength behaviour of the aniso­propic plate:
 

  • Maximum loads can be absorbed in the fiber direc­tion 0° and 90°. At an angle of 45°, a flexural strength of only approx. 50% of the 0° and 90° fiber direc­tion is measured. (Graphic: blue curve)


Bending strength behaviour of the isopropic plate:
 

  • The samples are showing a nearly constant bending strength at all test angles, (0° – 90° in 15° steps). In the course of the tests carried out, a maximum devi­a­tion of only about 15% occurred. (Graphic: red curve)


Conclusion:

The iso­tropic OCMC material suits far better for multi-axis stress condi­tions than the aniso­tropic OCMC material.

 

Full details of the experi­ment can be found in the original doc­u­ment at:

„Biegeversuche an anisotropen und isotropen oxid­keramischen Faser­verbund­werk­stoffen (OCMC)” (German)

Test implementation: Sandra Leonhardt and Frank Walter, Author: Sandra Leonhardt, published by: © Walter E. C. Pritzkow Spezial­keramik, (as of march 2021)


With new 3M Nextel® 610 fabrics, component costs can be reduced enormously.

At the same time our customers do not have to give up on quality.

The 3M Nextel® 610 oxide fibre fabric is an essential “basic material” of OCMC’s1. Therefore, its purchase price is a decisive cost factor in the produc­tion of simple and complex parts made of Keramikblech®.

As a result of a series of develop­ment stages with 3M Nextel® 610 fabrics, the DF11-3000 fabric had already proven itself in the pro­duction of OCMC last year. This had already made a cost reduc­tion of ten to fifteen percent in the produc­tion of Keramikblech® possible2.
 

Depending on the require­ments and com­plexity of the com­po­nents, the new type DF13-4500 allows a cost reduc­tion of up to 67%

Our com­po­nents made of Keramikblech® have to endure a lot and before their use they have to pass through the "torture chamber": tempera­ture, thermal shock and mechan­i­cal stress. The results of the qual­ity tests using the new fabric were en­cour­aging in this regard. Even more exciting: the price-per­formance ratio.
 

Go-ahead for use in Keramikblech® manufacturing

DF13-4500 is expected to be available for component manufacturing from April 2021.

1 OCMC = oxide ceramic matrix composites


The focal point of energy technology

Solar absorber compo­nents made of Keramikblech®:

Recently, sheet ceramic com­po­nents for a volumetric receiver of the Noor III solar tower plant have been com­pleted. Due to its excep­tional properties, sheet ceramic is interest­ing for hot gas gen­era­tion in this type of solar energy conversion, where thermally and mechanically highly loadable com­po­nents are required.

The American company Wilson Solarpower Corporation had devel­oped the tech­nical basis for the Brayton Cycle CSP* system, which there­upon has been marketed as 247Solar Plant™ by 247Solar Inc. This pro­pri­etary CSP* tech­nol­ogy uses hot air as a heat transfer medium instead of the usual steam or nitrate salt.

The solar absorber, designed as a volumetric receiver, is a central com­po­nent of the Noor III solar plant in Morocco. On top of the solar power tower, it heats the air passing through up to 970 °C. In combi­na­tion with a micro­turbine, this hot air is used to generate solar elec­tri­city. 

The basket like struc­ture made of sheet ceramic, (Keramikblech), holds the ceramic SiC foams together, where the heated air flows through. The combi­na­tion of SiC foams as the absorber material and the sup­porting struc­ture made of sheet ceramic, make the absorber per­fectly suited for these extreme challenges and will guarantee a long-term use at the same time.

In order to make a contri­bu­tion to the energy supply of our common future, we were glad about this task.

Thanks to our cus­tomers and part­ners for their great co­op­er­ation. 

*CSP = Con­cen­trating Solar Power
 

Further infor­ma­tion on this subject: 

  247solar.com

  247Solar Plants 3D Animation, (YouTube)


First test drive with an exhaust mani­fold made of sheet ceramic

In close co­opera­tion with Formula Student „Boden­see Rac­ing Team“ Con­stance an ex­haust mani­fold made of sheet ceramic was pro­duced. In early No­vem­ber, this ex­haust sys­tem was installed in the rac­ing car for a test drive.

Com­pared to metal, the fibre-re­in­forced ceramic does not corrode, is light, ther­mal in­sulat­ing and ex­tremely heat-resist­ant. The sheet ceramic com­po­nent could easily with­stand the vibra­tions during the test drive. Work­ing on the exhaust sys­tem was possible a few minutes after the test drive, because the ceramic ma­te­rial cools down much faster than metal. We are looking for­ward to the fur­ther devel­op­ment of this pro­ject.

More in­for­ma­tion about the pro­ject: homepage.brt-konstanz.de
 


Dawn of VTOL with sheet ceramic tech­nol­ogy

September 17, 2018:
Jetoptera, Inc. has commenced the Ver­ti­cal Take Off and Land­ing (VTOL) test cam­paign, demon­stra­ting capa­bil­i­ties to vertically take off and hover a test­bed of more than 50 kg.

A vertical launch of ground­breaking success:
the tests show an ex­cel­lent thrust vector control via a swiv­eling Fluidic Propulsive System™, (FPS™), which can be rotated more than 90 degrees out of the hori­zon­tal posi­tion for VTOL. The plat­form demon­stra­ted the excellent ma­neu­vera­bility and vertical takeoff capa­bil­i­ties. In addition, findings on demonstrate Short Take-Off and Landing / STOL capa­bil­i­ties.

This is the first time that the thin-walled thrusters made of sheet ceramic were employed for a VTOL test and its low weight properties enable the FPS™ capa­bil­i­ties.

All Jetoptera products except the J-55, including the four-seat VTOL aircraft “Jetoptera 4000”, are employing the pro­prie­tary fluidic propulsive system FPS™.

Further information can be found on the www.jetoptera.com

jetoptera.com/news/    the-J2000-flying-car


Jetoptera FPS system completes another flight test campaign

A second model – this time a glider – took to the skies on July 5th, 2018, powered solely by the Fluidic Propulsion System.

The successful test flight demon­strates the flexibility of the propulsion FPS™ concept used on various config­ura­tions of the airframe. The glider will be used as test bed for future shapes of the thrusters, including round and non-round, enabled by Walter E.C. Pritzkow special ceramics construc­tion method.

The advantages of the system: small size, distributed thrust and high speeds, low weight, simplicity, consider­able payloads and exceptional maneu­verability are obvious, and its scalability can be extended to the new concepts of urban air mobility.

These successful flights strengthen the coopera­tion between Walter E. C. Pritzkow special ceramics and Jetoptera, Inc. The ultralight ceramic sheet thrusters were key to keeping the weight of the FPS low and the thrust to weight ratio high. The flight and further technical details can be seen on the Jetoptera, Inc. Company website:

jetoptera.com/news/


Lift-off: „Keramikblech“ thrust nozzles in test flight of an unmanned aerial vehicle (UVA)

For the first time a component made of sheet ceramic, built into the model “J55”, takes to the skies. Edmonds / Washing­ton-based Jetoptera, Inc. devel­oped the Fluidic Propulsion System™, an innova­tive propulsion concept for an unmanned aerial vehicle. For the first time the fluidic pro­pul­sion technol­ogy was imple­mented on the airframe. A consistent devel­op­ment of fluid mechan­i­cal components, the imple­menta­tion of the latest ceramic tech­nol­ogies and innova­tive manu­fac­turing tech­niques are com­po­nents of the compact, revolutionary design.

The sheet ceramic were incor­po­rated into the thrusters of the model Jetoptera J55, due to the low density of the ceramic material, which is only 36% of the steel density, as well as its high thermal load capacity, especially devel­oped for this challenging task.

The test flight of the Jetoptera prototype on April 26 this year was a world premiere in terms of design and drive tech­nol­ogy for unmanned aerial vehicles, but also in regards of the wide range of applica­tions of the oxide ceramic fiber composite "sheet ceramic" in industry and research.

  More about: „Jetoptera“, article „Fluidic propulsion™ takes off“, Jetoptera on Linkedin 


“Keramikblech” flame tubes 15 years in successful use

Already 15 years ago, in 2002, flame tubes made of “Keramikblech” (sheet ceramic), were delivered for burners from the company Weishaupt for the first time. The first flame tube was installed by the large bakery Wendeln near Munich, (at that time already Kamps), in a baking line, on which the crispbread “Lieken Urkorn” was produced. This production line was sold in 2003 to Wolf Süsswaren in Arnstadt, Thuringia, where a second baking line was also equipped with flame tubes made of “Keramikblech". Both plants are still in operation. Today this industrial bakery is called “Grabower Süsswaren”.

The lifetime of metal flame tubes in 2002 was approximately 1000 hours. The durable flame tubes made of sheet ceramik are only replaced if they are mechanically damaged during maintenance. Therefore a more than 50,000 hours lifetime of “Keramikblech” flame tubes is about 50 times higher than the lifetime of metal flame tubes.

Further flame tube types for “Weishaupt burners” are mainly used in crematoria. In these applications the lifetime of 10 weeks is extended to more than 2 years.

  See also: Burner Components


Sliding carriage of the first generation after 2800 cycles:

The sliding carriage of the 1st generation, shown above, passed through 2800 cycles by now but still works with its fissures. The sliding carriage of the 2nd generation currently passed through 920 cycles.

The application temperature of these sliding carriages is between 1000 – 1140 °C. The cycle time amounts approx. 2 hours. It's loaded with test bodies, is pushed into the hot stove and pulled out again after a not known residence time.


Article of the magazine Ceramic Applications 2/2015

Further publications you can download as PDF file.