Spray or Vaporization Cooling of Permanent Molds-In this cooling system design,vertical passages in the mold are sprayed with water from nozzles located in the top manifold.

As water contacts the hot surface of the passages, it changes its physical state from liquid to steam. The necessary energy required for this state change is captured from the mold heat. Therefore, this significantly reduces the temperature of the mold. The condensed water then is collected at the bottom by the collector manifold.

The cooling passages can be cast into the mold blank or machined so that an elliptical cross-section (rather than a circular one) is achieved. The elliptical shape provides greater surface area for more effective heat transfer. The commonly used mold materials for this cooling method are iron or copper.

While this process is one of the most effective methods of mold cooling, it is a less uniform method. This lack of uniformity causes more thermal shock to the mold and, therefore, reduced the mold life.