Ultra-high pressure abrasive blasting

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The English term ultra-high pressure abrasive blasting (UHPAB) refers to a belonging to the blasting process surface preparation method , that is, a method that has a surface for coating by scarfing prepared (see FIG. DIN EN ISO 12944-4).

In UHPAB is a combination of pressurized water jets ( ultra-high pressure blasting , UHP) and dry blasting (engl. Abrasive blasting , AB). What is special about the UHPAB process is a two-stage acceleration mechanism with which the solid abrasive is first accelerated conventionally using compressed air (AB) in a first stage . The mixture of blasting media and compressed air is then accelerated a second time using a high-speed water jet (UHP). The resulting three-phase flow (blasting media, air, water) is bundled and hits the surface to be processed at high speed. The speeds of individual phases or acceleration levels are listed below.

  • Speed ​​of the abrasive after the first acceleration (air pressure: 0.8 MP) = AB: 162 m / s
  • Speed ​​of the water jet (water pressure: 200 MPa) = UHP: 633 m / s
  • Speed ​​of the abrasive after the second acceleration (air and water pressure as above) = UHPAB: 500 m / s

Numerous successful applications of the UHPAB process are known, in particular in the areas of ship repair , steel hydraulic engineering , weld seam processing , pipeline stripping as well as when working on drilling platforms and large storage tanks. The process has a number of application-related and qualitative advantages. These include in particular:

  • low dust generation
  • low specific abrasive consumption
  • low specific water consumption
  • low specific energy consumption / diesel consumption
  • high efficiency due to the high speed of the abrasive
  • high cleaning effectiveness (salts, broken abrasive) thanks to the water phase
  • Generation of a projected surface roughness
  • Ensuring high adhesion between substrate and coating
  • very good corrosion protection

The effectiveness of the method depends heavily on the conditions under which it is used; this includes u. a. Object geometry, accessibility, work organization and equipment. Area outputs of up to 20 m² / h can be achieved. As with all blasting processes, more complex geometries of the processed structures lead to a reduction in effectiveness with the UHPAB. The costs of the procedure are also based on the conditions of application, with regional and local conditions (e.g. wage level, work and environmental protection requirements) also being added.

Individual evidence

  1. ↑ AW Momber: Hydroblasting and Coating of Steel Structures. Elsevier, London 2003, ISBN 0-08-097248-9 .
  2. ↑ DIN EN ISO 12944-4: Coating materials - Corrosion protection of steel structures by coating systems - Part 4: Types of surfaces and surface preparation, 1998, Beuth-Verlag, Berlin.
  3. ↑ AW Momber, R. Godoy: Preparing offshore platforms with ultra-high pressure abrasive blasting-basics and cases . In: Journal of protective coatings & linings . tape 24 , no. 4 , 2007, p. 36-47 .
  4. ↑ a b c A. W. Momber, S. Koller, HJ Dittmers: Effects of surface preparation methods on adhesion of organic coatings to steel substrates . In: Journal of Protective Coatings and Linings . tape 21 , no. 11 , 2004, p. 44-50 .
  5. ↑ a b A. Momber: Aspects of salt concentration on prepared steel substrates . tape 23 , no. 2 . Journal of Protective Coatings and Linings, 2006, p. M2-M8 ( PDF ).
  6. ↑ a b A. W. Momber, S. Koller: Effects of surface preparation methods on delamination of organic coatings applied to a metal substrate . In: Journal of Protective Coatings and Linings . tape 25 , 2008, p. 43-52 .