Vaporizer

From GAWDAwiki

Vaporizers are used to convert cryogenic liquids in storage tanks into their gaseous forms. Ambient vaporizers are the most commonly used. These devices transfer heat from the surrounding air into the liquid moving through their coils. For situations requiring greater product flow, fan ambient, electric, steam and water vaporizers are also available.

Heat Transfer

The amount of energy required for a given heat transfer depends upon the quantity of gas required, how quickly it is needed, and the energy available. The speed and volume of air transferred can be determined by considering three factors.

Surface area (the area in which heat transfer occurs)
Temperature difference (the difference in temperature between the cold liquid and the heat source)
Heat transfer coefficient (a complex factor derived from experimental data and calculations)^[1]

When sizing a vaporizer, be sure to consider the duty cycle as well as the inlet pressure and desired pressure at the use point taking into consideration pressure drop. In some cases with heavy continuous usage, two vaporizers should be used with a diverter/timer switching assembly in order to allow for one of the units to thaw when not being used.^[2]