Drop erosion
As drops erosion or drop impact is called erosive wear by liquid droplets . Drop erosion is microscopic water hammer .
This effect occurs when drops hit a surface at high speed. Although water as a liquid is apparently "soft", the drops have an abrasive , eroding effect due to the incompressibility of the liquid and the high momentum and inertia . This leads to wear and tear on the surface if exposed to permanent effects .
Since high speeds usually occur in technical gas and steam lines and flow machines (local to supersonic ), the drops have a particularly strong effect, since the momentum is very high and since every deflection of the flow has a strong centrifugal separation effect.
Examples:
- Water injection coolers where there is insufficient distance for the droplets to evaporate until they are first deflected
- End blades of condensing turbines
- Drops of rain or mist when entering the turbo compressor of a jet engine or a gas turbine
The undesirable effect of drop erosion is harnessed in waterjet cutting.
literature
- Herbert Sigloch: Turbo machines . Basics and applications, Carl Hanser Verlag, Munich, ISBN 978-3-446-43242-0 .
- Karlheinz G. Schmitt-Thomas: Integrated damage analysis . Technology design and the system of failure, 3rd edition, Springer Fachmedien, Wiesbaden 2015, ISBN 978-3-662-46133-4 .
Web links
- Drop erosion and corrosion fatigue on a turbine blade (accessed August 2, 2018)
- Thomas Nemitz: Service life analysis and calculation of the remaining service life of turbo machines using the example of steam turbines in a power plant of a refinery and investigation of aspects of replacement procurement. (accessed on August 2, 2018)
- Network for erosion and corrosion protection layer development to increase the life cycle efficiency of systems relevant to energy strategy (accessed on August 2, 2018)