Performance of a Evaporator

There are three main measures of evaporator performance:

  1. Capacity (kg water vaporized/time)

  2. Economy (kg water vaporized/kg steam input)

  3. Steam Consumption (kg/time)

Note that the measures are related, since \[\text{Steam Consumption} = \frac{\text{Capacity}}{\text{Economy}}\]

  • Economy calculations are determined using material and energy balances.

  • The key factor in determining the economy of an evaporator is the number of effects.

  • The economy of a single effect evaporator is slightly closer to but less than 1. Multiple effect evaporators have higher economy in proportion to the number of effects.