Blasting of ship's hull with CO2 ice pellets
Abstract
Newly built ships made of steel covered with primer are cleaned of residue, oxides and soot from welding and gas cutting using CO2 pellets and a manual blasting equipment (pressed air operated), thereafter another corrosion protection paint is applied.
Description of the substitution
Newly built ships made of steel covered with primer are cleaned of residue, oxides and soot from welding and gas cutting using CO2 pellets and a manual blasting equipment (pressed air operated), thereafter another corrosion protection paint is applied.
On outside surfaces burnt in iron oxide has to be removed by angle grinder, this is a requirement set by the paint suppliers. Ships hull inside (cabins etc.); area of 300 m2 is cleaned during night shift.
The equipment used is Cryomax, manual CO2 blasting equipment driven by compressed air.
Before sandblasting was used as a cleaning method.
The example includes
Safety and health at work:
Yes
Environment:
Yes
Technical requirements the product must fulfil
On outside surfaces burnt in iron oxide has to be removed by angle grinder, this is a requirement set by the paint suppliers. Paint supplier determines the process since the guarantee depends on an approved surface treatment.
The hull has to be free of oil and grease, dry. Cleaning quality: absence of oxide, mill scales, mineral oils (from engraving), and cutting oils on the metal surfaces of the piece.
The subsequent process is long term corrosion converting coating (more than one year), Primer (airless).
What problems made you look for a substitution?
-
What substance or product did you use before?
Before sandblasting was used as a clenaning method.
What solution did you find?
Manual CO2 blasting
Assessment of the solution
Since the agent is produced from waste gases, a closed loop is achieved on global level. The agent sublimes, so only the dirt remains, which can be disposed of via municipal channels.
If rust has crept already under the first primer layer this CO2 pellets process must not be applied, also fat and coffeine containing dirts need to be pre-treated (may be with a solvent)
Blasting with CO2 dry ice-pellets or snow flakes: On ships (or something like a ship) the German statutory accident insurance (BG, "Gesund + Sicher" 11/2002) recommends in addition to TRGS 507 the following safety measures:
One blast-operator per room
The blast-operator should use a breath protection independet from the surronding air
The room should have exhaust and forced air (capacity of exhaust min. 9000 m3/h)
Efficiency of exhaust should be checked
Exhausted air should be led into the open, the space around the discharge nozzle should be roped off 5m
Lower rooms should be blocked and aerated
Blasting equipment and blasted object should be connected to ground
Work should be conducted outside normal working time
What other solutions did you try/assess?
Breakdown into industries
Iron and metal, electronics and automotive industries
Who entered the example?
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Company:
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Cooperation Centre Hamburg
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Name:
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Klaus Kuhl
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Address 1: |
Besenbinderhof 60
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Address 2: |
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Zip code: |
20097
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City: |
Hamburg
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E-mail: |
k.kuhl@kooperationsstelle-hh.de
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Type: |
Organisation
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Created by:
Klaus Kuhl
Wednesday, June 25, 2008
Last edited by:
Klaus Kuhl
Wednesday, June 25, 2008
569
k.kuhl@kooperationsstelle-hh.de
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