Compound fertilizer dryer Introduction

Compound fertilizer rotary dryer is a kind of drying equipment that widely used in the compound fertilizer production line, after the fertilizer come out of the rotary drum granulator, it will enter the rotary drum dryer, through rotational motion and the hot air contact, the material is being dried. The specification of the compound fertilizer rotary drum dryer is determined based on the local weather and also the characteristic of the raw materials. Tongli compound fertilizer rotary dryer usually are designed in pairs to ensure a better drying effect and precise process control, the fertilizer produced by our dryer has a better quality. After the granular fertilizer is added to the dryer, it is evenly distributed and dispersed in the dryer under the agitation of the flights or lifting plates, and fully contacts with the hot air in parallel (countercurrent) flow, which accelerates the drying heat transfer and mass transfer.

Compound fertilizer dryer structure

A compound fertilizer rotary dryer is a type of industrial equipment used to dry and process compound fertilizers. The purpose of a rotary dryer in the context of compound fertilizer production is to remove moisture from the granules or particles of the fertilizer mixture. This drying process is important because excessive moisture in compound fertilizers can lead to issues such as clumping, caking, reduced shelf life, and decreased effectiveness of the nutrients when applied to plants. The Compound fertilizer rotary dryer is composed of, dryer shell, dryer riding ring, dryer girth gear, dryer transmission unit, dryer hood cover and so on.

Dryer Shell: The rotary dryer shell is the main body of the dryer, where the material is loaded and rotated. It has a cylindrical shape and is equipped with lifting plates or flights to lift and disperse the material. The drum is heated by hot air or gas that flows through it, either in parallel or countercurrent direction. The drum transfers heat to the material and evaporates the moisture.

Dryer Flights: Rotary dryer flights, also known as "flights" or "lifters," are the inclined, curved structures that are attached to the internal shell of a rotary dryer. A rotary dryer is a device used to remove moisture from materials like powders, granules, and bulk solids through the process of drying. It consists of a large cylindrical drum that rotates while the material is fed into one end and is discharged from the other end after being dried.

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

Dryer pinion: The pinion is an essential part of the rotary dryer drive system, responsible for transmitting rotational motion and torque from the driving mechanism to the rotary dryer 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 dryer. When the pinion is rotated by the drive system, it drives the girth gear, causing the rotary dryer to rotate.

Dryer bearing housing: The bearing housing serves as the support structure for the dryer's rotating motion and is responsible for holding and guiding the dryer's trunnion bearings. Trunnion bearings are large, heavy-duty bearings that support the weight of the dryer 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 dryer. The bearing housing provides a stable mounting point for the trunnion bearings and ensures proper alignment of the dryer's rotation. It is typically designed to accommodate the axial and radial forces generated during the rotation of the dryer.

Dryer Hood Cover: The rotary dryer hood is located at the discharge end of the kiln and provides sealing to retain heat and gases. The rotary dryer 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 dryer Transmission device: The transmission device of the rotary dryer 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 dryer, 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 dryer and the quality of the products being processed. Usually, the rotary dryer 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 compound fertilizer rotary dryer

Counter-flow design: In order to achieve the best drying effect, Tongli Compound fertilizer rotary dryer adopts the counter-current drying method. The material and the heat source enter the drying equipment from the other side. Compound fertilizer rotary dryer has the feature of high temperature resistance, and can use high temperature hot air to quickly dry the materials.

Flights: The equipment has made many technical innovations in the lifting device system, especially adopting a new type of multi-combination lifting device, which overcomes the “wind tunnel” phenomenon of traditional dryers.

Structure: Tongli Compound fertilizer rotary dryer has achieved innovation in the internal structure, strengthened the cleaning and heat transfer effect on the dispersed materials, and eliminated the sticking phenomenon on the inner wall of the drum.

Versatility: Tongli Compound fertilizer rotary dryer has strong scalability, and the design considers the production margin. Even if the output increases slightly, there is no need to replace the equipment.

Feeding and discharging: Tongli Compound fertilizer rotary dryer uses a new type of feeding and discharging device, which prevents the Compound fertilizer rotary dryer from feeding blockage, discontinuity, unevenness and return phenomena, and reduces the load of your dust removal system. 

Specifications of compound fertilizer dryer

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

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Industry Knowledge extension

What is the difference between rotary dryer and rotary kiln?

Rotary dryer: A rotary dryer is used to remove moisture from materials, such as minerals, ores, chemicals, food products, and biomass. The primary purpose of a rotary dryer is to reduce the moisture content of the material through the application of heat and the movement of the material within the drum. In a rotary dryer, materials are fed into the rotating drum, and hot gases or air are introduced to evaporate the moisture. The material is tumbled and agitated as it moves through the drum, allowing for efficient drying. Rotary dryers operate at elevated temperatures to facilitate drying, the temperatures used are generally lower compared to those in rotary kilns. Rotary dryers are used in industries such as agriculture, mining, chemicals, and food processing to remove moisture from bulk solids, powders, and other materials.

Rotary Kiln: A rotary kiln is designed for high-temperature processes, such as calcination, sintering, pyrolysis, and other thermal treatments. It's used to process raw materials or products at elevated temperatures, often in a controlled atmosphere, to bring about physical or chemical changes in the material. In a rotary kiln, materials are typically fed into one end of the kiln and gradually move towards the other end. The kiln is heated to very high temperatures, and the material undergoes chemical reactions, phase changes, or thermal treatments as it progresses through the kiln. Rotary kilns operate at much higher temperatures, often reaching well over 1000 degrees Celsius (1800 degrees Fahrenheit), depending on the specific process. These high temperatures are necessary to achieve the desired chemical or physical transformations in the material. Rotary kilns are used in industries such as cement production, lime calcination, metallurgy, and waste incineration. They are designed for processes that require high-temperature reactions, phase changes, or material transformation.

What is the difference between incineration kiln and rotary kiln?

The fundamental difference lies in the purpose of the equipment. Rotary kilns are used for various high-temperature material processing operations, while incineration kilns are specifically designed for waste combustion and disposal.Rotary kilns process raw materials, minerals, and other materials for various industrial applications. Incineration kilns process waste materials, aiming to reduce waste volume and ensure proper disposal.

Rotary kiln: A rotary kiln is primarily used for high-temperature processing of materials. It is widely used in industries such as cement, lime, minerals, and more. Its primary purpose is to carry out processes like calcination, sintering, roasting, and other thermal treatments. In a rotary kiln, the material to be processed is placed on a rotating refractory-lined drum. The material moves through the kiln due to the rotation of the drum, and it is exposed to high temperatures for the desired thermal transformation.

Incinerator kiln: An incineration kiln is specifically designed for the thermal treatment of waste materials, typically with a focus on waste disposal and environmental considerations. It is used to combust waste materials at high temperatures to reduce their volume and convert them into inert residues. In an incineration kiln, waste materials are introduced into a controlled combustion environment, where they are subjected to high temperatures and combustion gases. The process is designed to break down organic materials and reduce waste to ash and gas.

Both types of kilns involve high temperatures, but incineration kilns are operated at even higher temperatures to achieve complete combustion of waste materials.Incineration kilns are subject to strict environmental regulations due to the potential emission of pollutants. Special measures are taken to control emissions, ensure clean combustion, and minimize environmental impact. Rotary kilns also have environmental considerations, but the focus is primarily on optimizing the thermal processes.