Liquid generators, their operation is based on burning silver iodide acetone solution. The disadvantage of this design is:
small ice-forming activity of aerosols in the range -1 ÷-6 ° C,
which can be explained as an uncontrolled expansion of the ice-forming substances in the flame and the small size of the particles formed during combustion.
the complexity of the equipment used to run and maintain the operating mode of the generator
the need to store large amounts of pressure (100 - 200 liters) of flammable gases and liquids,
which poses a serious danger in case of emergency operation of the generator.
significant impact on the use of generators and has a very high cost of installation.
Generators that use refrigerants, namely LPG, CFC, liquid nitrogen.
Action of generators based on cooling of the working area of the fog droplets and freeze it.
Subsequently the frozen droplets act as nuclei of crystallization.
Although these generators have a high ice-forming activity in the area of temperatures ranging from minus 1оC, using variants of the generator
with liquid propane in some cases (airports) are forbidden because of the high fire danger refrigerant.
Used as a refrigerant CFC is highly desirable for environmental reasons.
Generators using liquid nitrogen have a limited operational readiness of the inability to store
liquid nitrogen for extended period of time (usually no more than a week).
Besides the use of generators is connected with the obligatory presence of the production of liquefied gases in a relatively short distance, since transportation of liquid nitrogen is also well-known difficulties.
All generators of this type have a common drawback: they are effective only within a supercooled fog.
Use them at a distance from the zone or zone of warm mist (which can then get into the zone with negative temperatures) is impossible.
Pyrotechnic generators designed for continuous operation, include pyrotechnic devices of considerable length.
These generators are more autonomous and fireproof as possible for simultaneous combustion of the entire mass of pyrotecnic composition,
however, due to the necessity of the item for at least 15-30 minutes (total running time of assembly should be up to 10 hours) must be
use of elongated charges, length of 30 cm or more. Under these conditions, under advancing flame front pyrotecnic composition inside the body of generator and as a consequence of
increase the time of location products of burning in the area of high
temperatures or deposition of combustion products on the cold walls, activity of the resulting aerosol is significantly reduced.
Situation to some extent, can improve the establishment of additional nozzles along the entire length of the charge, but this can lead to
more expensive technological decision, and it's don't lead to decision problem at whole.
So under burning the pyrotechnic systems in length about 50 cm ice-nucleation activity of aerosol in the end of work by 1-2 orders of magnitude
smaller than at the start of work of the generator.