BLASTRAC EBE

A combination of enclosed and open blast-cleaning is a successful combination for the complete solution to a project.
However, for open surfaces Blastrac EBE enclosed machines will give the optimum result.
Using the very outdated method of open blast-cleaning, where an abrasive (usually copper slag, cool slag, garnet but sometimes dried sand) is driven onto the work surface under reasonably high velocity by the means of compressed air passing through a hose and nozzle system into which the abrasive has been automatically mixed at the abrasive container vessel, good surface preparation is usually achieved at the expense of major disadvantages.

Disadvantages of open blasting
 Labour extensive requiring a crew of two personnel per nozzle, which at best can only produce an average of six square metres per hour over a working day.
 Economically expensive, large capacity compressor required to give a minimum of 300 cfm of air at 100 psi per nozzle.
 Large amount of dust and debris produced by using a total loos type of abrasive, high capicity ventilation required to enable visibility for the nozzle operator.
 Impossible for any other trades to work within a tank that is being cleaned, also impossible to inspect the quality of the work whilst in operations are being performed.
 Very large clean up operation required before any painting can be carried out, and a massive tank cleaning project at the end of the operations, this clean will bring about tons of debris to be disposed of (about 1 tonne per 25 square metres).
Advantages of using open blast-cleaning system
 All surface areas can be processed without any accessibility problems.

Blastrac EBE Enclosed machine blast-cleaning.
The working principals of Blastrac EBE equipment is based on the law of kinetic and mechanical energy.
The cleaning operations are performed by steel abrasives (a steel shot, and steel grit mix) being thrown at high velocity against the surface to be cleaned up to an SA norm. The throwing action is achieved through centrifugal force, where the wheel blades located radially are rotated at high speed.

The shot is fed on to the revolving wheel and is fed in such a manner that it travels along the radial length of the blades and then is thrown off in high velocity streams at the surface to be cleaned, this abrasive is then cleaned and returned for re-use within the machine on a continuous basis.

The dust and debris cleaned from the abrasive are drawn into a remote Dust Collector usually positioned on the outside of the tank, or in the vecinity of the shot-blast machine.

Advantages of this system
 Two man crew per machine that will produce an average square metres per hour on a continuous basis (24 hour operation is possible if the machine operators are available on a shift basis and required maintenance checks are done)
 Economical, the cost of supplying power is very low when compared to compressed air costs.
 Dust free whilst cleaning operations are being carried out.
 Possible for other trades to work within a close proximity of the machine, allowing continuous inspection of the quality of cleaning produced, and over coating of previously cleaned areas. (dependant on the type of coating specified)
 Final clean up is not required, the minimal cleaning requirements that have to be carried out prior to painting can be done by means of vacuum cleaning as part of the painting operations, the total amount of debris produced only amounts to the corrosion removed from the work surface, and the very small amount of abrasive reduced to dust during the machine working operations.
 The quality of blast-cleaning/SA norm is continually monitored by the machine operator and the process controller, any blemishes found will be rectified immediately by reversing the machine, then re-blasting that small area (if applicable)
 Profile requirements for particular coatings are usually specified, profile produced on the work surface is controlled by the size and type of abrasive used, a typical starting mix would be a 75% steel shot size 460 together with 25% steel grit 25 size, the machine operator, advised by the contract controller usually determine the abrasive mix by trial and profile measurement at the start of the operations, as work progresses some wear on the abrasive is inevitable, shot and grit can be added to the mix by scattering it in front of the machine as it is working. The machine will pick it up and thus add it to the mix until the originally specified profile is produced, all this is an ongoing part of the quality control system used by the machine operator and the contract controller