An
essential equipment for processing gas in all gas plants, a gas generator is
actually a propellant mixture that burns to produce large volumes of gas.
Gas generators provide an onsite supply of gas, humidity (water vapor) or
vapor removing the requirement for delivery in gas cylinders, which can be
bulky and may have special storage requirements. The basic purpose of gas
generators is to provide a continuous supply of high purity gas from
existing compressed air. Besides being used in gas plants, gas generators
are used in a variety of applications like general industrial, general
laboratory, wastewater treatment and disinfection, chromatography, odor
control, air pollution and calibration.
The working process
The working mechanism is similar to a rocket propellant but designed
specially to produce large volumes of cool gas. The low temperature in the
generator allows the gas to be put to use more easily in many applications.
The gas generator works on the principle of disassociation of water/moisture
to produce ultra-high purity gas. All generators use a combination of
filtration and molecular sieves to produce different gases suited to
different instruments. There are different types of gas generators depending
on the gas to be produced in the gas plant.
Types of Gas Generators
Gas Generation Technologies
Common gas generation technologies are as follows:
- Exothermic
- Endothermic
- Cryogenic
- Dissociation
- Membrane or molecular sieve
- Vacuum pressure swing adsorption (VPSA}
- Water electrolysis or electrolytic
Types of gases produced by Gas Generators
- Chlorine dioxide
- Humidity or water vapor
- Hydrogen
- Nitrogen
- Oxygen
- Ozone
- Zero air
Technical specifications
There are several parameters to consider in specifying gas generators. They
are as follows:
- Concentration: Refers to the gas generated. Expressed in
parts per million (ppm).
- Purity: The purity of the gas is expressed as a percentage.
- Flow rate: Refers to the flow out of the generator of the gas
generated.
- Inlet pressure: It is the maximum pressure of inlet gas that
the generator can bear.
- Outlet pressure: It is the maximum outlet pressure of the gas
generated that the generator can bear.
Other features to consider are:
- Portability
- Overheat shutdown
- Optional air compressors
- Replaceable desiccant cartridges to provide minimum humidity
- Some gas generators in addition to gaseous products may also produce
liquid gas products.
Gas
Generator
