Vertical roller mill used in cement plants

A vertical roller mill is a type of industrial equipment used to crush or grind materials into small particles. It is widely used in the concrete and cement manufacturing industry due to its high efficiency and energy-saving capabilities. In this article, we will explore the key features, working principles, and benefits of vertical roller mills used in cement plants.

The primary function of a vertical roller mill is to grind materials into extremely fine powder for use in various industrial processes. The raw materials used in cement production, such as limestone, clay, and iron ore, are crushed and homogenized into a mixture called raw meal. This raw meal is then heated in a preheater and kiln system to produce clinker, which is the intermediate product in the cement manufacturing process. The clinker is further ground with gypsum and other additives to produce cement.

Here are the key features and components of a typical vertical roller mill:

Grinding table: It is a flat surface where the raw materials are pulverized. The grinding table is driven by a motor and rotates on a horizontal axis. The material is fed onto the grinding table and is crushed and ground by the rollers.

Rollers: The rollers exert pressure on the grinding table and grind the raw materials. They are typically made of steel and can be adjusted to control the fineness of the ground material.

Grinding rollers: These are the primary grinding components in a vertical roller mill. They rotate around their own axis and exert pressure on the material on the grinding table. The rollers can be individually or jointly suspended on a spring-loaded system to maintain a constant grinding pressure.

Separator: The separator is responsible for separating the ground material from the airflow in the mill. It ensures that the desired product fineness is achieved and that oversized particles are returned to the grinding table for further grinding.

Working principles of a vertical roller mill:

Material feed: The raw materials are fed into the mill through a central chute or by means of a conveyor belt. They fall onto the grinding table and are crushed and ground by the rollers.

Grinding: The rollers exert pressure on the grinding table and grind the material. The ground material is transported by the airflow generated by the mill’s fan and is collected by the separator.

Separation: The separator separates the ground material from the airflow. The fine particles are carried by the airflow and collected in the product cyclone or bag filter, while the coarse particles are returned to the grinding table for further grinding.

Benefits of vertical roller mills in cement plants:

High efficiency: Vertical roller mills have a higher grinding efficiency compared to ball mills, which results in lower energy consumption. This is because the vertical design of the mill allows for more effective grinding and better utilization of the available mill power.

Space-saving design: Vertical roller mills have a compact design, which makes them suitable for installation in confined spaces. They require less floor area compared to traditional ball mills, allowing cement plants to optimize their layout and use the available space efficiently.

Flexibility in grinding: Vertical roller mills can grind various materials, including raw materials, clinker, and slag. They offer flexibility in terms of adjusting the fineness and particle size distribution of the ground material, allowing cement producers to produce different types of cement to meet market demands.

Low maintenance: Vertical roller mills require less maintenance compared to traditional ball mills. They have fewer moving parts, which reduces the risk of mechanical failures and lowers the overall maintenance costs for cement plants.

Environmental benefits: Vertical roller mills produce less noise and dust compared to traditional ball mills. They also have a lower environmental impact due to their lower energy consumption, which contributes to the sustainability efforts of cement manufacturers.