Liquefaction hydrate, formation

The atmospheric-pressure hydrate formation temperature of 9.6°C quoted above is one of the constraints on operating temperatures in chlorine cooling. Later, we shall also consider the effects of chlorine hydrate in liquefaction systems (Section 9.1.7.2C). The same problem of equipment plugging may occur there, and the melting or decomposition of hydrate when equipment is taken out of service and allowed to warm can result in severe corrosion. International Critical Tables data for the decomposition pressure of chlorine hydrate, which extend to 16°C, fit the equation... 

We saw above that in the early stages of liquefaction water tends to accumulate in the gas phase. This keeps the liquid-phase concentration of water low and works against the formation of solid hydrate. In addition, the temperature is often higher in these early stages. This fact increases the solubility of water in the liquid chlorine, again discouraging hydrate formation. Hydrate accumulates more frequently in the later stages. 

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