The steam economy in a single effect evaporator system refers to the efficiency of steam usage in the evaporation process. It is defined as the ratio of the amount of water evaporated to the amount of steam consumed.

The steam economy can be calculated using the following formula:

Steam Economy = (Amount of Water Evaporated) / (Amount of Steam Consumed)

In a single effect evaporator system, only one stage of evaporation is used. This means that the system operates with a single set of steam and condensate circuits. The steam is used to heat the feed liquid, causing evaporation to occur. The resulting vapor is then condensed to produce the concentrated product, while the condensate is either recycled or removed from the system.

The steam economy in a single effect evaporator system is typically lower compared to multi-effect evaporator systems. This is because in a single effect system, all the heat required for evaporation is supplied by the steam. Therefore, a larger amount of steam is needed to evaporate a given quantity of water compared to a multi-effect system, where the latent heat of the vapor is used to heat the subsequent effects.

In summary, the steam economy in a single effect evaporator system is generally less efficient compared to multi-effect systems, as it requires a higher amount of steam to evaporate a given amount of water.