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Postal addres:
Derustit Holland B.V.
It Dok 1
8447 GL Heerenveen,
The Netherlands.
Tel: +31 (0)513 610215
Fax: +31 (0)513 620225
Email: info@derustit.nl
K.V.K. nr: 01057316
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Introduction to Blasting
Blasting in General
Blasting refers to a high-speed impact of a projectile on a target. The projectile can be either discrete, as in solid media blasting, or continuous, as in water blasting. Solid media have a range of abrasivity, hardness, angularity and size. Solid media has been traditionally used for material erosion and is commonly known as abrasive blasting. When abrasivity decreases, erosion rate also decreases, as shown in Figure 1.
Abrasive Blasting
In applications where erosion is to be controlled, solid media of low abrasively such as plastic media, starch media, glass beads, etc. are used. For solid media of low abrasivity, the impact action is mainly displacement. One aspect of solid media blasting is the generation of dust and secondary solid waste from spent media. Therefore, abrasive blasting is not a cleaning process.
Water blasting
Water Blasting is non-abrasive therefore its applications relate mainly to cleaning. Although at very high pressures, water is used for cutting as in water jetting. For effective cleaning, normally detergents or other cleaning chemicals are added to the water. The impact action is primarily rinsing. In many applications the water is recycled, thereby requiring water treatment as additional process and cost. Generally water blast uses a large volume of water, in the range of 1000-2500 Liters per hour. The treatment cost for such a high volume can be considerable. |
Figure 1. Erosion by Abrasive Blasting |
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Ideal Blast
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Clean but No Damage |
In an ideal cleaning application,
the deposit is removed completely with no damage to the substrate.
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Figure 3. Ideal Blast Cleaning
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Figure 4. Ice is a phase change media |
Ice as media
Ice is a phase change media. Ice starts as a solid and changes into a liquid. Therefore it possesses the combined characteristics of both solid and liquid blasts. Ice is not abrasive, therefore is only marginal in erosion applications. Erosion by ice blast is a result of impact fracture, not abrasive action. Being a phase change material, ice does not generate dust on impact and does not require a large volume to do useful work.
Ice is a phase change media. Ice starts as a solid and changes into a liquid. Therefore it possesses the combined characteristics of both solid and liquid blasts. Ice is not abrasive, therefore is only marginal in erosion applications. Erosion by ice blast is a result of impact fracture, not abrasive action. Being a phase change material, ice does not generate dust on impact and does not require a large volume to do useful work. |
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Crystalline Ice as blasting media
combines the characteristics of both solid and liquid blast
The mechanism and benefits of ice blast will be discussed in greater detail in next section.
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