In the previous article we described the two basic types of blast cabinets. And we have focused mainly on projection systems. However, a cabin is much more than this.
Whenever we talk about abrasive spraying, the word powder comes to mind as a logical consequence.
Indeed, when an abrasive is sprayed on a surface, the following will unfailingly occur:
– We will remove material from the surface (either structural material or waste).
– We are going to have a fractionation of the projected abrasive (according to its friability)
And as a consequence we are going to generate dust… But there is a third element in this mixture, indeed! The abrasive that is still in good condition to be reused. Let us not lose sight of the fact that these machines work in a closed projection/recovery/projection circuit. In these conditions and depending on the application to be addressed, we must consider whether we need expansion boxes prior to the filter, or cyclones or selection towers in high-level applications such as shot peening and controlled roughness, which are required in fields such as aeronautics, wind power, or precision mechanics.
The booths must always incorporate a suction/filtration system. Residual dust even if there is no emission of dust to the outside of the booth is a problem. If we consider the different consumption elements and quantify them on an hourly basis, we will realize that all of them added together are low in relation to the cost/hour of the operator. Well, the dust and the lack of vision that comes with it waste costly time for the operator. A good blasting booth can be easily distinguished by the fact that it should be easy to see inside while the operator is blasting. The hourly cost and productivity depends on it.
And finally, the structure of the booth itself is of great importance; there is nothing more annoying for the operator than a booth that leaks dust. And this annoyance becomes detachment to the equipment, which leads to poor maintenance and consequently low productivity, entering a vicious circle.
The best carpentries are those that have been shaped as much as possible by folding, since the fewer joints, welds, etc… The more watertight they are.
The designs with hood-type cabins, which are raised frontally halfway up the cabin, are the ones that lose the most dust. Fortunately, it is an obsolete design that hardly anyone uses anymore. Access hatches should have seals and closures with progressive tensioners to compensate over time for seal caking.
These issues, together with good nozzle materials, laminated glass and good lighting, make the difference between a mediocre machine that generates dissatisfaction, dust and low production and a good machine that everyone is willing to use.