In the following article, we analyze blasting booths and their function with the different types of technologies used to spray surface finishing abrasives.
In specific situations where it is not possible to spray abrasives using compressed air in enclosed areas, this can be done in the open air, also known as free jetting.
Large structures, whether civil works, buildings, silos, ships, are usually blasted by this method due to the physical inability to do it in an enclosure.
However, there are several disadvantages to consider: environmental, economic (it is difficult to recover the projected abrasive), and quality (since we cannot collect, we use abrasives of poor quality).
Whenever it is possible, therefore, and there is obviously a repetitiveness, we will use blasting booths or blasting rooms. We can differentiate them by these names cabins / rooms depending on whether the operator is outside the blasting area (cabin) or inside the blasting cabin (rooms). Although it is very common to call both types blasting or sanblasting cabins in Mexico and other Central American countries.
Also known as sleeve booths, because the operator accesses the manipulation of the nozzles or blasting guns by means of gloves or sleeves.
This type of machines can either fire in suction (or Venturi) or in direct pressure.
Blasting booths at Venturi
They are the most common and are easily recognizable because two hoses are attached to the trigger gun, which also looks like a pistol itself. One of them, the lower one, connects it to the abrasive, the other one connects it to the compressed air.
The operation is simple, the compressed air coming from the compressor generates a suction effect (Venturi) when it reaches the gun, which raises the abrasive from a lower tank until it reaches the gun, where it meets the jet of compressed air, mixing both and shooting out of the nozzle.
This type of machine is used in most applications for cleaning, satin finishing, deburring of alloys, etc. with abrasives such as glass beads or corundum.
Direct pressure blasting booths
When it is intended to address other applications where more intensity is required, such as paint stripping, creation of high roughness or simply to increase productivity, the firing system described above is replaced by a direct pressure or overpressure firing system.
For this purpose, the booth is connected to a sandblaster, blower or pressure group, whatever we want to call it. This group is usually installed under the cabin to receive by gravity the thrown material and close the circuit, or also located, for more technical applications and/or designs, on the side of the cabin and in many occasions with a cyclone above for the selection of abrasive/waste.