Electric Actuators are a vital component in processing aggregates for use in the cement industry.

Cement Composition and Concrete Variability

The main ingredients that make up cement are limestone, clay, silica sand, along with other materials like gypsum and iron ore. Cement acts as a binding agent when mixed with water and aggregates to form concrete. Different types of concrete can be made by combining different combinations of aggregates. Blending different sizes of aggregates can customize the concrete mixture to meet specific performance criteria for a variety of applications. Fox example, different recipes would be used for structural, decorative or high-performance concrete.

In addition, these different mixtures also affect the mechanical properties of the concretes including compressive strength, tensile strength and impact resistance.

Aggregate Handling and Delivery in Cement Production

In many cement producing facilities, large silos that can be 80-100 feet tall, are filled with different sizes of aggregates and are arranged in a row. Each silo has a metering gate situated at the bottom, that is opened and closed by a RACO electric actuator. The specific recipe will ultimately determine which mixture of aggregates is used. The RACO actuator must be precise in their operation to ensure the correct mixture is produced. Therefore, they can be equipped with electronic end of stroke limit switches and an absolute encoder that can produce a 4-20mA feedback signal to allow for these precise operations. Furthermore, the actuators must be able to stand up for the harsh environment and rigorous operating conditions they are exposed to every day. By operating the gates, the RACO actuators release the correct mixture of aggregates on to a conveyor belt which runs below the silos. This conveyor belt then transports the aggregate mixture on to waiting railcars, where the aggregate mixtures are then delivered to the customers to fulfill their specific concrete recipe.