Two basic systems for dry ice blasting
The first is a direct acceleration (single pipe) system: this system introduces dry ice particles into the air stream at the funnel rather than at the nozzle opening, which allows dry ice to be faster at 900 ft/s (1 ft = 3
0.48 cm). Get out of the nozzle port (300 ft/s if using the dual pipe system described below) for better cleaning results. If you do not need such a large amount of cleaning energy, simply lower the pressure of the compressed air to reduce the spray of dry ice particles.
The second is the Venturi system (dual pipe system): this system is at the nozzle opening, where small dry ice particles are drawn into the air by vacuum and the nozzle opening is facing the mold surface. This system is less expensive than a single pipe system, but it is difficult to remove the heavy residue and dirt on the mold because it cannot achieve the high speeds that can be produced by a single pipe system.