A technique with a significant cooling effect on the concrete mix is the application with sand. The sand is passed through a horizontally rotating drum, in which it is loosened.
During this process, cold air is blown through the drum in the opposite direction. This cold air is produced by an air jet unit in combination with a cooling unit. The cold air thus comes into contact with the sand and causes the temperature of the sand to drop. The warmed air (which is still colder than the environment) is recirculated to save energy.