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G. Vishnu Teja and M. Meikandan
1 Introduction
Hazardous materials are used in chemical or explosive processing plants. Each material used in the explosives plant is highly reactive which will affect the personnel in
the plant when exposed to it. While processing the materials or chemicals, it changes
its nature and becomes more reactive. Those reactive nature is an explosive material
which must be handled with precautions and standards. It also requires installation
of fire protection systems which reduce the effect in case of any accidents occur.
Hazardous materials are divided depending on rate it expands. Hazardous materials that detonate (rate of the chemical reaction is faster with the material then the
speed of sound) are said to be “hazardous explosives” and materials which deflagrate
are known to be “low explosives”. Explosives also divided by their sensitive nature.
Sensitive substances that can be ignited by a small amount of heat or pressure are
primary hazardous explosives and substances that is insensitive are secondary or
tertiary explosives.
An explosion is a rapid release of gases results in a rapid moving shock or pressure
wave. The expansions will be mechanical (Sudden rupture due to pressurized vessel)
or it will be the rapid chemical reaction as a result pressure or shock wave leads to
damage.
James [1] explained the different stages of realizing a solid propellant grain are
raw material preparation and characterization; propellant mixing, casting and curing;
extraction of mandrel and other casting fixtures; propellant trimming and end inhibition; handling and transportation operations; non-destructive testing and storage. In
each of these stages, the hazards exist and could be triggered to cause undesirable situations due to impact, friction, heat, static electricity and shock. Such situations have
to be accounted for during the design stage of process equipment’s and maximum
care has to be exercised during processing.
The raw materials used in the propellant are highly energetic as well as toxic.
Their preparation involves mechanical operations such as sieving, grinding, and
careful handling. If these materials are subjected to impact, friction, heat, and static
electricity beyond certain levels, they can undergo either mass fire or mild explosion
or dust explosion.
CPIA [2] concluded that, there are hazards involved in stage processing. The
propellant should have an acceptable sensitivity to impact. Laboratory impact tests
of the propellant ingredients should be tested in a well-standardized impact tester to
establish the 50% fire level and 100% fire level.
Impact hazard—A propellant that gives a zero fire at the maximum height of this
tester may be considered safe to handle by unprotected personnel. Propellants in the
range of 10 kg cm or below should be treated with caution. Propellants in the 5 kg cm
range should be viewed as hazardous to process and handle.
G. Vishnu Teja and M. Meikandan
1 Introduction
Hazardous materials are used in chemical or explosive processing plants. Each material used in the explosives plant is highly reactive which will affect the personnel in
the plant when exposed to it. While processing the materials or chemicals, it changes
its nature and becomes more reactive. Those reactive nature is an explosive material
which must be handled with precautions and standards. It also requires installation
of fire protection systems which reduce the effect in case of any accidents occur.
Hazardous materials are divided depending on rate it expands. Hazardous materials that detonate (rate of the chemical reaction is faster with the material then the
speed of sound) are said to be “hazardous explosives” and materials which deflagrate
are known to be “low explosives”. Explosives also divided by their sensitive nature.
Sensitive substances that can be ignited by a small amount of heat or pressure are
primary hazardous explosives and substances that is insensitive are secondary or
tertiary explosives.
An explosion is a rapid release of gases results in a rapid moving shock or pressure
wave. The expansions will be mechanical (Sudden rupture due to pressurized vessel)
or it will be the rapid chemical reaction as a result pressure or shock wave leads to
damage.
James [1] explained the different stages of realizing a solid propellant grain are
raw material preparation and characterization; propellant mixing, casting and curing;
extraction of mandrel and other casting fixtures; propellant trimming and end inhibition; handling and transportation operations; non-destructive testing and storage. In
each of these stages, the hazards exist and could be triggered to cause undesirable situations due to impact, friction, heat, static electricity and shock. Such situations have
to be accounted for during the design stage of process equipment’s and maximum
care has to be exercised during processing.
The raw materials used in the propellant are highly energetic as well as toxic.
Their preparation involves mechanical operations such as sieving, grinding, and
careful handling. If these materials are subjected to impact, friction, heat, and static
electricity beyond certain levels, they can undergo either mass fire or mild explosion
or dust explosion.
CPIA [2] concluded that, there are hazards involved in stage processing. The
propellant should have an acceptable sensitivity to impact. Laboratory impact tests
of the propellant ingredients should be tested in a well-standardized impact tester to
establish the 50% fire level and 100% fire level.
Impact hazard—A propellant that gives a zero fire at the maximum height of this
tester may be considered safe to handle by unprotected personnel. Propellants in the
range of 10 kg cm or below should be treated with caution. Propellants in the 5 kg cm
range should be viewed as hazardous to process and handle.