General Spray Condensers

A spray condenser is a type of direct-contact condenser. One advantage of such a condenser is that it is relatively simple and inexpensive to produce. It also offers a greater efficiency than shell and tube condensers, due to a greater surface area for heat transfer produced by the droplets. The method is simple; water cooled below the dew point of the air in the condenser is sprayed at an optimum droplet size, and the water vapor condenses while releasing a latent heat of condensation.  This latent heat can be utilized by a heat exchanger, and thus converted into energy for other uses in the desalination process.  Also increasing efficiency, part of the exit stream of water leaving the condenser may be recycled and used as the spray for the humid air. 

A diagram of a typical spray condenser is shown in Figure 8.

Spray Condenser

1. Water inley

2. Spray

3. Incondensables outlet

4. Inlet of humid vapor

5. Condensates outlet

As seen in Figure 8, the process of a spray condenser is relatively straightforward.  In the design depicted in the diagram, water is sprayed at point 1. At point 4, the humid vapor is introduced into the spray condenser. Point 5 is where the condensed water exits the condenser.  Any incondensible materials leave the condenser at point 3.  Although the spray condenser design for this particular project differs from this particular figure, this is an adequate model to conceptually explain spray condensers.

Next
Condenser Design
Specific Design Considerations
Calculations and Computer Analysis