Rotary Dryer

What is Rotary Dryer?

A rotary dryer, also known as a drum dryer, is a commonly used dewatering equipment in industrial settings. Its primary function is to reduce the moisture content of materials. Rotary dryers have a drum-shaped design, hence the name. Over time, industrial development has led to the optimization and improvement of rotary dryer structures.

Modern rotary dryers have been developed to meet the diverse requirements of various materials, such as fly ash, kaolin, silica sand, gypsum, iron sulfide, coal, sawdust, slag, limestone, and more. Zoneding, as a professional rotary dryer manufacturer, continually optimizes their rotary dryers and offers a range of drying equipment options to suit different needs.

Rotary Dryer

Reasonable Structure ensures the Drying Efficiency

With advancements in drying technology, the structure of rotary dryers has been optimized for improved processing efficiency. Each part of the rotary dryer plays a specific role in achieving this.

The main body of the rotary dryer is a horizontally positioned drying cylinder that rotates through gears. It includes a feeding port, discharge port, and the cylinder itself. A spiral feeding plate is installed at the feeding port for easy material feeding, while a material-holding ring is placed at the discharge port to prevent the expulsion of disqualified material. Inside the cylinder, lifting plates are welded on the inner wall to enhance the drying process. These plates can be welded into different angles and shapes based on the specific requirements.

The drying cylinder is supported by a supporting device comprising a wheel belt, supporting wheel, and thrust rollers. The wheel belt covers the cylinder and is supported by wheels, while the thrust rollers control the axial movement of the cylinder within 5mm.

To ensure smooth operation and minimize temperature fluctuations, the supporting device is filled with water and oil, with the oil often being recycled waste oil.

The driving device of the rotary dryer operates similarly to other machines. The cylinder is driven by a triangle belt, big gear, small gear, and reduction gear.

Special attention is given to the sealing plates used in Zoneding rotary dryers. These dryers typically have multiple stainless steel plates at the joints of the feeding and discharge ports, which varies depending on the model. Stainless steel plates provide good elasticity, heat resistance, and adaptability to the cylinder’s bouncing motion during rotation. This design minimizes heat loss and enhances drying efficiency.

For a better understanding of how the supporting device operates and how the gears function, you can refer to the provided video showcasing a Zoneding rotary dryer in action at a working site.

The Application of Rotary Dryer

Rotary dryers find extensive applications in various industries for drying particles and granules that are smaller than 5mm. In cases where the material is too large, it is recommended to use a small crusher machine for initial breaking.

The strong adaptability of rotary dryers makes them suitable for use in cement plants, coal industry, mines, and building material production, among other industrial fields.

For instance,

In cement plants, rotary dryers are used to dewater fly ash, pozzolana, and other similar materials to meet the requirements of cement production.

In the recycling field, rotary dryers are utilized for drying sludge and other waste materials that contain rich organic matter, which can be recycled as fertilizer.

In mining, rotary dryers are commonly used in ore beneficiation plants after the wet grinding process. The rotary dryer helps to dry the ore pulp after the pressure filter, resulting in the production of fine powder.

These are just a few examples of the applications of rotary dryers. Their versatility and effectiveness in drying various materials make them indispensable in several industries.

 

Examples of Rotary Dryer Applications

The Classification of Rotary Drum Dryer

The classification of rotary drum dryers is based on their structure and heat transfer mode.

Structure-wise, rotary dryers can be classified as single-cylinder type and multi-cylinder type. The single-cylinder rotary dryer has a simpler structure and is easier to maintain, while the multi-cylinder dryer is more complex and maintenance can be more challenging.

Heat transfer-wise, rotary dryers can be categorized as direct type and indirect type. The co-current rotary dryer and direct dryer are commonly used for most applications. The co-current type ensures effective drying for materials with small particle size to prevent backflow.

However, in certain cases, counter-current rotary dryers and indirect heat transfer dryers are recommended. Counter-current dryers are suitable for products with a moisture requirement below 5% and have higher drying efficiency. Indirect heat transfer dryers are used to prevent material contamination from direct combustion.

These classifications provide guidance for selecting the appropriate type of rotary drum dryer based on specific drying needs and considerations.

The working principle of a rotary dryer is based on gravity and heat exchange. Let’s take the counter-current rotary dryer as an example to explain the process:

The dryer is positioned horizontally at a slight angle (usually around 5°). The material to be dried is introduced into the cylinder of the dryer.

The cylinder is rotated, causing the material to move forward through the dryer. This movement is facilitated by lifters or plates inside the cylinder that lift and drop the material as the cylinder rotates.

At the same time, hot air is introduced into the dryer from the opposite end. The hot air flows in the opposite direction to the movement of the material, creating a counter-current flow.

As the material and hot air move in opposite directions, heat exchange occurs. The hot air transfers its heat to the material, causing the moisture within the material to evaporate.

The evaporated moisture is carried away by the hot air, resulting in the drying of the material.

The length of the cylinder is carefully calculated to ensure that the material is dried to the desired moisture level by the time it reaches the outlet of the dryer.

Once the material has reached the desired moisture level, it is discharged from the outlet of the dryer.

This working principle applies to rotary dryers in general, with some variations depending on the specific type of dryer used.

Figure-1. Rotary Dryer Working Principle

Zoneding offers rotary dryers with several advantages that make them suitable for different types of factories:

1. Optimal drying efficiency: Zoneding rotary dryers have a carefully calculated ratio of length and diameter, ensuring the ideal retention time for materials inside the dryer. This helps achieve a satisfactory drying effect. Additionally, the designed angle of the lifting plates increases the thermal contact area without damaging the materials, improving heat exchange efficiency.
2. Strong adaptability: Zoneding rotary dryers are simple in structure and can be designed to meet the drying requirements of various materials. The ratio of length and diameter can be adjusted to accommodate different material characteristics. This adaptability extends to the site requirements as well, allowing for customization based on available space.
3. Versatile heat sources and fuels: Zoneding dryers offer the flexibility to choose the most suitable heat source and fuel based on factors such as cost and environmental considerations. The dryers can be heated by oil, gas, wood, steam, or other sources, while the fuel options include oil, electricity, and more.
4. Easy maintenance and operation: Zoneding rotary dryers are designed for easy maintenance, ensuring smooth and hassle-free operation. The operation of the dryers is simple and user-friendly, making it convenient for factory personnel to operate and maintain the equipment.

Overall, Zoneding rotary dryers provide efficient and adaptable drying solutions for a wide range of materials, with options for heat sources and fuels, easy maintenance, and simple operation.

Benefits of Rotary Dryer

Rotary Dryer Shipment

Rotary Dryer Manufacturer

Zoneding Machine is a reputable manufacturer of rotary dryer machines. With extensive experience in dewatering technology, Zoneding offers reliable and customized drying solutions to meet the specific requirements of customers. Our team of professional engineers provides expertise in designing and optimizing drying flowcharts.

Zoneding Machine operates a specialized factory with experienced operators, ensuring the production of high-quality rotary dryers. Our commitment to quality ensures that customers receive reliable and efficient drying equipment.

In addition to manufacturing, Zoneding Machine also offers competitive prices for rotary dryers, making them affordable for different budgets. We understand the importance of pricing in the decision-making process, and we strive to provide cost-effective solutions without compromising on quality.

Furthermore, Zoneding Machine has a dedicated after-sales service team that is responsive and reliable. We are committed to providing excellent customer support, addressing any inquiries or concerns promptly and effectively.

From the initial customized drying solution to competitive pricing and reliable after-sales service, Zoneding Machine is a trustworthy choice for rotary dryer manufacturing.

service provided to customer

General Specification

Spec./m (Dia.×Length)	Shell Cubage (m³)	Capacity (t/h)	Installation Obliquity (%)	Highest Inlet Air Temperature (℃)	Main Motor (kw)	Weight (t)
Φ1.2×8.0	9.0	1.9～2.4	3～5	700～800	7.5	9
Φ1.2×10	11.3	2.4～3.0	3～5	700～800	7.5	11
Φ1.5×12	21.2	4.5～5.7	3～5	700～800	15	18.5
Φ1.5×14	24.7	5.3～6.6	3～5	700～800	15	19.7
Φ1.5×15	26.5	5.7～7.1	3～5	700～800	15	20.5
Φ1.8×12	30.5	6.5～8.1	3～5	700～800	18.5	21.5
Φ1.8×14	35.6	7.6～9.5	3～5	700～800	18.5	23
Φ2.2×12	45.6	9.7～12.2	3～5	700～800	22	33.5
Φ2.2×14	53.2	11.4～14.2	3～5	700～800	22	36
Φ2.2×16	60.8	13.0～16.2	3～5	700～800	22	38
Φ2.4×14	63.3	13.5～16.9	3～5	700～800	37	45
Φ2.4×18	81.4	17.4～21.7	3～5	700～800	37	49
Φ2.4×20	90.4	19.3～24.1	3～5	700～800	45	54
Φ2.4×22	99.5	21.2～26.5	3～5	700～800	45	58
Φ2.6×24	127.4	27.2～34.0	3～5	700～800	55	73
Φ3.0×20	141.3	30.1～37.7	3～5	700～800	75	85
Φ3.0×25	176.6	37.7～47.1	3～5	700～800	75	95
Φ3.2×25	201	42.9～53.6	3～5	700～800	90	110
Φ3.6×28	285	60.8～76.0	3～5	700～800	160	135

Technical parameters of indirect heat dryer:

Shell  diameter ×shell  Length   Items	Inside  diameter  of outer  shell (mm)	Inside  diameter  of inner  shell (mm)	Shell  Length (m)	Shell  cubage (m³)	Shell  obliquity	Lifting  blade  form	Highest  inlet air  temperature (℃)	Dimensions (m)
Φ1.5×15m	1500	500	15	20.27	3-5%	Lifting form	850	16.2×2.7×2.7
Φ1.5×17m			17	22.97				18.2×2.7×2.7
Φ1.5×19m			19	25.68				20.0×2.9×2.9
Φ1.8×21m	1800	650	21	35.91	3-5%	Lifting form	850	22.5×2.7×2.7
Φ1.8×23m			23	39.33				24.5×2.9×2.9
Φ1.8×25m			25	42.75				26.5×2.9×2.9
Φ2.2×21m	2200	800	21	58.10	3-5%	Lifting form	850	—-
Φ2.2×23m			23	63.61
Φ2.2×25m			25	69.15

Please note that the information provided is based on the current data and technology available. As technology advances, the data and specifications may change without prior notice. The performance of the machine may also vary depending on the specific application and conditions.

For the most accurate and up-to-date information, I would recommend chatting online with Zoneding engineers. They will be able to provide you with detailed and customized solutions based on your specific requirements.