Dry ice blasting generally uses one of two delivery systems to combine compressed air with ice and accelerate particles out of the delivery nozzle:
Single-hose technology uses a single hose to deliver air blasts and dry ice. The single hose system can use a longer hose than the double-hose counterpart without a significant drop in pressure when the ice leaves the hose. The additional power comes at the cost of increased complexity. Single-hose systems are used when the surface to be cleaned has a heavier build-up or when the surface to be cleaned is vertical or at a greater height than the hopper and air compressor.
Double-hose dry ice blasting was developed before the single-hose system. Compressed air is delivered in one hose, and ice pellets were sucked out of a second hose by the venturi effect. Compared with a single-hose system, the two-hose system delivers ice pellets with less force than a single-hose system. Theoretically two-hose systems have a limit to the vertical distance between the machine and applicator. This limit however is well in excess of 7.62m or 25 feet. Two-hose systems are generally less costly to produce due to a much simpler delivery system and they allow finer particles of ice to be delivered with lower velocity as the late combination of warm air with cold ice results in less sublimation in the hose. The latter properties allow for more delicate surfaces to be cleaned.
Dry ice blasting is truly, and completely, environmentally friendly.