Activated carbon, a functional material with a highly porous structure and strong adsorption properties, is widely used in a variety of fields, including water treatment, air purification, chemical engineering, food processing, and pharmaceuticals. The activated carbon rotary kiln, a core piece of equipment in its production process, directly determines the quality and efficiency of the activated carbon product.

The activated carbon kiln is a continuous heat treatment device specifically designed for the production of activated carbon. Based on the general operating principle of a rotary kiln, it heat-treats (activates) carbonaceous raw materials (such as wood, fruit shells, and coal) at high temperatures to produce activated carbon products with specific pore structures and adsorption properties.

Compared to static kilns, rotary kilns provide a more uniform heat treatment environment, thereby enhancing the activity and adsorption capacity of the activated carbon. By precisely controlling the calcination conditions, activated carbon with tailored pore structures and adsorption properties can be produced to meet the needs of diverse applications.

Working principle of activated carbon kiln

The operating principle of an activated carbon kiln is based on the rotary motion of the drum and the high-temperature pyrolysis and activation processes. Activated carbon raw materials enter the preheater at the kiln’s rear end and then into the drum. Because the drum is tilted and slowly rotates, the material undergoes two types of motion within the kiln: tumbling in a circular direction and axial movement from the upper end to the lower end.

During this process, the material undergoes three main stages:

Drying stage: This removes volatile components and moisture from the raw materials.

High-temperature carbonization stage: At temperatures reaching 800-900°C, organic matter in the raw materials boils, vaporizes, and desorbs, or undergoes decomposition reactions to produce small hydrocarbons, which are then desorbed. The remaining components become “fixed carbon.” To prevent oxidation, this stage is typically performed under vacuum or an inert atmosphere.

Activation stage: This cleans the activated carbon’s micropores and restores its adsorption properties, a critical step in the entire production process. The resulting exhaust gas is treated and discharged to the atmosphere through an exhaust pipe.

Activated Carbon Kiln Equipment Structure

An activated carbon kiln primarily consists of the following components:

Cylinder: Made of high-quality steel plate and lined with refractory bricks, it serves as the heat treatment chamber for the material.

Support: This includes a roller assembly and a retaining wheel assembly, which support and secure the rotary kiln to ensure stable operation.

Drive: This includes a main drive and an auxiliary drive system, with the auxiliary drive preventing deformation of the kiln body during power outages.

Kiln Head and Kiln Tail Sealing: The kiln head utilizes a shell-type seal, while the kiln tail is equipped with an axial contact seal to ensure reliable sealing.

Airflow System: This regulates the kiln atmosphere and controls the pyrolysis and activation process of the activated carbon.

Control System: This utilizes a PLC automatic control system to monitor and control parameters such as the rotary kiln’s speed, temperature, and feed rate.

Technical Advantages of Activated Carbon Kiln

Activated carbon kiln offer several significant advantages over traditional production equipment:

Easy Operation: Utilizing a PLC automatic control system, all operating steps are reflected on a computer terminal, allowing easy operation of the equipment via computer control, streamlining the process and reducing operating costs.

Environmentally Friendly and Energy-Saving: Virtually no dust is emitted during operation, and no exhaust gas is discharged. The equipment utilizes a sealed design, internal heat recycling, and a filtration function to effectively prevent the generation and emission of exhaust gas.

Low Energy Consumption: Utilizing advanced combustion technology, exhaust gas can be reused as energy, reducing environmental pollution, utilizing waste, and significantly reducing production costs.

High Production Efficiency: Continuous automated operation improves production efficiency.

Stable Product Quality: Precisely controlling temperature, atmosphere, and material residence time enables the production of activated carbon products with uniform pore size distribution and excellent adsorption properties.

Activated Carbon Kiln Process

The activated carbon kiln process includes the following key steps:

Raw Material Preparation: Carbon-rich materials such as wood, fruit shells, and coal are selected as raw materials and initially crushed and screened.

Feeding: Raw materials are added to the kiln outlet via a feeder and slowly moved toward the kiln outlet, driven by the kiln’s tilt and rotation.

Heating and Activation: A fuel chamber is located at the kiln outlet, allowing hot gases generated by the combustion of coal gas or crude oil to enter the kiln directly, moving from the kiln outlet to the kiln outlet. During this process, the raw materials undergo three stages: drying, high-temperature carbonization, and activation.

Cooling: The activated activated carbon is discharged from the kiln outlet and cooled in a cooler.

Post-Processing: The cooled activated carbon undergoes screening, packaging, and other processes before becoming the finished product.

In actual production, the temperature can be adjusted according to the amount of material to achieve the desired result. The secondary air entering the kiln can also be preheated to above 700°C, fully utilizing waste heat and saving energy.

Key Points for Operating an Activated Carbon Kiln

Proper operation is crucial to ensuring the proper functioning of the activated carbon kiln and ensuring product quality:

Temperature Monitoring: Timely monitoring of the kiln temperature allows for accurate understanding of the kiln’s temperature trends, providing a basis for adding external fuel.

Applications of Activated Carbon Kiln

Activated carbon produced by activated carbon rotary kilns is widely used in the following areas:

Water Treatment: Used for adsorption and decolorization in water treatment processes, removing organic pollutants and odors.

Air Purification: Used for adsorption and purification of harmful gases in air purification systems.

Chemical Industry: Used in catalyst preparation to improve reaction efficiency.

Environmental Protection: Used for exhaust gas treatment and waste disposal to reduce environmental pollution.

Food and Beverage Processing: Used for food decolorization, deodorization, and purification.

Pharmaceutical Industry: Used in pharmaceutical purification and separation processes.