Fig. 9.4 Gas-flow furnace for generating very small oxygen pressures

The closed-system analysis can be applied to this open system by considering the gas to consist of small packets (circles in Fig. 9.4) in which equilibrium is attained. The method is useful when the required oxygen pressures are too small to be reliably maintained in an He/O2 gas mixture.

Typical applications where the oxygen pressure is critical are corrosion testing and control of the oxygen contents of ceramics.

Example The C02/C0 ratio in the gas entering a furnace at 2000K is 2 and no 02 is present. Because the equilibrium concentration of oxygen in the hot zone is quite small (about 1% in the closed-system example above), a good approximation is to set the C02/C0 ratio in the equilibrium gas equal to 2 as well. Using Eq (9.27), this yields the result:

Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

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