1070-4272/05/7804-0674 C 2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 4, 2005, pp. 674!676. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 4, 2005,
Original Russian Text Copyright + 2005 by S.Sokol’skii, Fedosov, A.Sokol’skii, Barulin.
Thermal Treatment and Hydrophobization of Components
of Fire-Extinguishing Powders
S. A. Sokol’skii, S. V. Fedosov, A. I. Sokol’skii, and E. P. Barulin
Ivanovo State Academy of Architecture and Building, Ivanovo, Russia
Ivanovo State University of Chemical Engineering, Ivanovo, Russia
Received October 28, 2004; in final form, January, 2005
Abstract-Experimental data on the thermal treatment and hydrophobization of components of fire-ex-
tinguishing powdered formulations in an apparatus with active hydrodynamics of a two-phase flow are
Fire-extinguishing formulations have the form of
a powdered mixture of various inorganic salts and
dopants. Depending on the fire-extinguishing capacity
of their components, the mixtures can contain am-
monium sulfate, ammophos, carbon white, nepheline,
talcum, sodium hydrocarbonate, aerosil, potassium
chloride, sodium chloride, etc. The main active com-
ponents of fire-extinguishing powdered mixtures are
ammophos and ammonium sulfate, which form a fu-
sion cake at 1603200oC and thereby screen an inflam-
mation site from interaction with atmospheric oxygen.
The rest of the additives, such as talcum and carbon
white, impart fluidity to the fire-extinguishing powder
and protect it from caking. The moisture content of
the components of fire-extinguishing mixtures should
not exceed 0.5 wt %.
To prevent caking and to raise the fluidity of pow-
ders, a mixture is hydrophobized. Such organosilicon
liquids as GKZh-94, Penta-804, MN-15, et al. are
used as water repellents . Most frequently, either
main active components or additives introduced into
the formulation are subjected to hydrophobization .
In the industry, the components are dehydrated in var-
ious drying apparatus, and then some of the dried-up
substances are subjected to hydrophobization. To save
expensive water-repellent agents, that component of
the mixture is treated, which has the highest capacity
for moisture absorption under normal atmospheric
conditions. It would be the most expedient to combine
the processes of thermal treatment of a component
and its hydrophobization. Such combined processes
can be carried out effectively in vortex apparatus in
a high-temperature heat carrier under conditions of
a high relative velocity of the interacting phases,
which provide an intensive removal of moisture from
the material and a high degree of polymerization of
a water repellent.
The components of fire-extinguishing powdered
formulation were heat treated and hydrophobized in
an installation shown schematically in Fig. 1. The in-
stallation contained the following units: whirlpool
Fig. 1. Schematic of the experimental installation.