Plasma & Plasma-Arc
Plasma, often referred to as the "fourth state of matter" is a special form of ionized gas that conducts electricity. It exists in the "white glow" that surrounds lightening bolts and is the major component in stars, including the sun. Although plasmas can be generated in a wide range of temperatures reaching millions of degrees (e.g. for fusion reactors), typical industrial uses of thermal plasmas are at temperatures in the range of 5,000 - 10,000ｰC (9, 000-18, 000ｰF).
Plasma Thermal heating technologies were widely developed in the early 1960's in conjunction with space exploration and military applications programs in the US (NASA) and the former Soviet Union. In particular, plasma torches were developed to provide an effective method to test the effectiveness and durability of heat shields required for space vehicle re-entry. PEAT's plasma heating systems convert electrical energy into thermal energy. Controlled plasma arcs are generated when a steady flow of gas is forced between electrodes with a high electrical current flowing between these electrodes. This now ionized gas generates an intense heat in the form of a plasma arc column or "plume".
Plasma arcs create an ultra-high energy environment where the energy density is greater than the bonding energy between the elemental atoms that form molecules. When the molecules that form the waste are fed into the plasma arc, the molecules are dissociated into their basic elemental atomic constituents. This dissociation permanently and totally destroys the molecular compounds and their properties
PEAT's plasma heating system consists of DC-powered graphite electrodes rather than plasma torches, typically marketed by other companies. There are a number of benefits associated with using DC-powered electrodes.
. Minimization of capital costs as graphite electrodes generate plasma-arc directly with exposed anodes and cathodes without requiring an independent torch. Plasma torches are expensive and increase the capital costs associated with overall systems.
. Minimization of operational costs as graphite electrodes require no water cooling or any externally-supplied carrier gas (i.e. argon or nitrogen). This increases the electrical to thermal conversion rates (typically seen between 75-80% in PTDR systems). Plasma torches require water cooling, carrier gases and have lower efficiencies as their power output can be as low as 50% of the power input for small torches. This means that one half of the electricity of the torch is dissipated to the cooling water or efficiency of the power supply.