The cooling of sands coming from shakeout is extremely important in order to avoid problems due to excessive temperature, such as difficult bentonite activation, difficult control of prepared sand compactability, higher water demand, etc..
The aim is to obtain sand with a temperature below 45°C. We think it is likewise important to favour the maximum homogenization of the sand itself.
Operating Principle
The physical principle applied in this plant is the removal of evaporation heat of water in contact with sand by means of the forced suction of vapor formation in the tank.
Sand is continuously mixed by mixing tools. At the same time, fluidizing air is added to guarantee an increase of heat exchange surface between sand and air.
The cycle begins with the inlet of cooling and moisturizing water, then hopper opens and used sand is charged. Thus, the cooling cycle is active from the very first mixing instants.
The vapor formation due to contact between water and sand is continuously removed by the suction system.
Vapors removed must be treated with a dry filter in order to satisfy emission limits prescribed by positive law.
The cooler we usually use is a batch cooler, as we think it is a kind of process more easily controllable and less influenced by stops (for instance, change of templates, lack of cast iron, etc.).
In fact, a batch process (charge / cooling / discharge) determines incoming and outcoming parameters on defined parts of sand, so that it is extremely easy to add just the quantity of water required.