Activated carbon rotary kiln Introduction

Activated carbon rotary kiln is a kind of equipment specially designed for calcining activated carbon. Activated carbon is a carbon-based adsorption material produced from various carbon-containing materials through appropriate processes. Due to its huge specific surface area, excellent adsorption performance and stable physical and chemical properties, it has been widely used in various fields. Rotary kiln for calcination (two-stage kiln) carbonization. During the operation of the activated carbon rotary kiln, the slurry that has been homogenized to meet the is fed requirements into the kiln by the feeder at the kiln head to calcine the activated carbon raw material, and the fuel is injected from the kiln head and burned in the kiln, and the heat emitted is heated to the raw material. The raw material is calcined and finish product is discharged from the bottom of the kiln shell, enters the cooling machine, and is collected after cooling.

Activated carbon rotary kiln structure

Rotary kiln thrust roller：The thrust roller is a critical part of the rotary kiln system. It serves the purpose of supporting the kiln's weight and maintaining its axial position, ensuring that the kiln remains properly aligned along its axis. The thrust roller is typically positioned on the downhill side of the kiln and is attached to the kiln shell, it consists of a central shaft or journal and a roller assembly.

Rotary kiln pinion: The pinion is an essential part of the rotary kiln drive system, responsible for transmitting rotational motion and torque from the driving mechanism to the rotary kiln itself. It consists of a gear wheel with teeth that mesh with the teeth of a larger gear, often referred to as the "girth gear" or "ring gear." The girth gear is attached to the outer shell of the rotary kiln. When the pinion is rotated by the drive system, it drives the girth gear, causing the rotary kiln to rotate.

Rotary kiln bearing housing: The bearing housing serves as the support structure for the kiln's rotating motion and is responsible for holding and guiding the kiln's trunnion bearings. Trunnion bearings are large, heavy-duty bearings that support the weight of the kiln and allow it to rotate smoothly. These bearings are subject to high loads, extreme temperatures, and potentially harsh environments due to the nature of the processes occurring inside the rotary kiln. The bearing housing provides a stable mounting point for the trunnion bearings and ensures proper alignment of the kiln's rotation. It is typically designed to accommodate the axial and radial forces generated during the rotation of the kiln.

Kiln Shell: The rotary kiln shell is a thick, steel cylindrical structure that provides the necessary strength and rigidity to withstand the high-temperature environment inside the kiln. It also serves as a containment vessel for the materials and gases during the manufacturing process. Inside the kiln shell is the refractory lining usually refractory bricks or sometimes refractory castable. Tongli kiln shell has good sealing performance, the edge of each shell is machined smoothly, enhance the sealing and service life of the rotary drum.

Kiln Hood Cover: The rotary kiln hood is located at the discharge end of the kiln and provides sealing to retain heat and gases. The rotary kiln operates under the negative pressure, therefore Tongli implied SS304 lining plate and ceramic felt both in the front and back end to prevent heat leakage.

Rotary Kiln Transmission device: The transmission device of the rotary kiln is mainly composed of main transmission, auxiliary transmission, mechanical thrust roller/hydraulic thrust roller, motor, gearbox and other components. The unique design of tongli transmission can greatly improve the service life and safety performance of the equipment.

PLC control system: A PLC is a digital computer-based system that is designed to control various industrial processes automatically. In the context of a rotary kiln, a PLC is used to monitor and control parameters such as temperature, rotation speed, air flow, fuel flow, and other critical variables that affect the performance of the kiln and the quality of the products being processed. Usually, the rotary kiln control system is integrated in the whole factory’s plc system, therefore we will provide the on-site cabin and a signal cable to the central plc.

Design principles of activated carbon rotary kiln

High Temperatures: The kiln operates at elevated temperatures to cause chemical reactions that activate the carbonaceous material. These reactions involve the removal of volatile compounds and the development of the material's characteristic porous structure.

Rotational Movement: The kiln rotates to ensure even heating and thorough mixing of the material. This rotational movement helps achieve consistent activation throughout the material.

Controlled Environment: The kiln's environment is carefully controlled to prevent excessive combustion of the carbonaceous material while still promoting the necessary chemical reactions for activation. This might involve adjusting the flow of air or steam into the kiln.

Retention Time: The material spends a specific amount of time within the rotary kiln to allow the activation process to occur. The retention time is carefully controlled to achieve the desired level of activation.

Cooling Zone: After activation, the material exits the high-temperature zone of the kiln and enters a cooling zone. This prevents further activation and allows the material to cool down before being collected.

Specifications of activated carbon rotary kiln

Note: *The diameter is the inner diameter, Weight excludes refractory material.

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Industry Knowledge extension

What is the application of activated carbon?

Water Purification: Activated carbon is used to remove organic compounds, chlorine, and other impurities from drinking water and wastewater. It helps improve taste, odor, and overall water quality.

Point-of-Use Filters: Activated carbon filters are commonly used in household water filtration systems, including pitchers, faucet attachments, and under-sink filters.

Municipal Water Treatment: Activated carbon is used in larger-scale municipal water treatment plants to remove organic matter and residual disinfection byproducts.

Indoor Air Quality: Activated carbon filters are used in air purifiers to remove volatile organic compounds (VOCs), odors, and airborne pollutants from indoor air.

Industrial Gas Processing: Activated carbon is used to purify gases in industrial processes, such as removing impurities from natural gas and hydrogen.

Soil and Groundwater Cleanup: Activated carbon can be used in remediation projects to adsorb and remove contaminants from soil and groundwater, such as volatile organic compounds (VOCs) and heavy metals.

Gold Mining: Activated carbon is used in the extraction of gold from cyanide solutions in the gold mining industry. Gold ions are adsorbed onto the carbon surface, which is then collected and further processed to recover the gold.

Toxin and Drug Poisoning: Activated carbon can be administered orally or through gastric lavage to adsorb ingested toxins and drugs, preventing their absorption into the body.

Food and Beverage Processing: Activated carbon is used to decolorize, deodorize, and remove impurities from food and beverage products, such as sugar, edible oils, and alcoholic beverages.

Chemical Purification: Activated carbon is used in various chemical processes to purify chemicals and remove impurities.

What is the difference between rotary kiln and vertical roller mill?

The rotary kiln and vertical roller mill are both essential pieces of equipment in the cement manufacturing process, but they serve different purposes and are used at different stages of the process.

The rotary kiln is a large cylindrical vessel used for calcining raw materials at high temperatures. It's a core component of the cement manufacturing process and is responsible for transforming raw materials, particularly limestone and clay, into clinker. In the rotary kiln, the raw materials are heated to temperatures exceeding 1400°C (2552°F), where chemical reactions occur that result in the formation of clinker nodules. And they need to be ground into a fine powder to produce cement. This final grinding process is often performed using a vertical roller mill. The clinker is mixed with gypsum and possibly other additives to create the final cement product.

Vertical Roller Mill (VRM): The vertical roller mill is a grinding machine that grinds materials into fine powders, after the raw material is crushed by the crusher, it enters the vertical roller mill. It is typically used for grinding raw materials, clinker, and additives in the cement manufacturing process. The VRM operates by applying hydraulic pressure and vertical force to the grinding rollers, which then grind the materials between the rollers and the grinding table. This grinding process results in a fine powder that is later used as a key ingredient in the production of cement which is important for the subsequent chemical reactions in the rotary kiln.