Ice Blasting Seminar

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  • Topic: Ice, Industrial processes, Water
  • Pages : 18 (3770 words )
  • Download(s) : 620
  • Published : September 30, 2011
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Chapter 1


1. Introduction
It's a process in which dry ice pellets are accelerated in a jet of compressed air that strike the coating to be removed at velocities up to the speed of sound. It cleans without the side effects of applications like water jet cleaning, sand blasting or solvents. It is a revolutionary alternative to traditional methods of cleaning. This technology is being utilized in Oil Fields, Power Plants, Mines, and a wide variety of other industrial and manufacturing industries. 2. History

The Department of National Defense in Canada contracted Dr. Sam Visaisouk to determine the feasibility of ice blasting for cleaning in confined spaces such as inside ships. The prospect of a dustless abrasive blasting process was very appealing on environmental and worker safety compliance grounds. This effort led to the first operating commercial ice blast machine in 1992. These ice blast machines had complex operating system controls and required frequent defrosting as very cold air was used for fluidizing and transporting ice particles from source to nozzle. At that time, any ice blockages were attributed to partial melting of ice particles, which would favor agglomeration. The use of very cold fluidizing air was deemed absolutely necessary. Periodic system defrosting was required as a result. During this period, other methods of ice blast were introduced elsewhere. Gary Settles of Penn State University patented a process in which a cryogenic fluid froze atomized water in a nozzle for blasting. A French version (briefly licensed by Schlick) utilized liquid nitrogen to freeze small water droplets to form ice particles for blasting. Both of these processes relied on cryogenic fluid at very low temperatures and could not be easily scaled up for robust industrial requirements. In 1996 Sam Visaisouk took a drastic change in the method of producing and fluidizing ice particles that resulted in patent US5, 913,711. He and Norm Fisher later produced a working model, patents US6, 001,000 and US6, 270,394. This breakthrough method remains the base of the state of the art ice blast systems to date till 2003. 1.3 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. A simple impact phenomenon involves 2 bodies. The projectile normally called the blast media can be spherical or angular, large or small, hard or soft, solid or liquid and projected at a variety of speed and angle towards the target. In general the user has no choice in terms of nature of target the user’s choice is in the media property and condition of blasting.

1.3.1 Abrasive Blasting
In applications where erosion is to be controlled, solid media of low abrasivity 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.

2. 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.

3. Ice Blasting
Ice blast is a cleaning technology which is essentially a hybrid between abrasive (i.e. sand) and non-abrasive (i.e....
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