Quartz sand rotary dryer Introduction

Quartz sand dryer is a kind of industrial drying equipment that can dry various minerals, such as quartz sand, river sand, and silica sand. Quartz sand is a kind of sand that is rich in silicon dioxide and is widely used in glass, ceramics, metallurgy, chemical industry, and other fields. Quartz sand dryer can reduce the moisture content of the quartz sand to the required level by using hot air or gas as the heat source. Quartz sand dryer is an important equipment for the quartz sand industry, it can improve the value and utilization of the quartz sand and meet the market demand.

Quartz sand rotary dryer structure

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 quartz sand rotary dryer

The design principles of a sand rotary dryer are centered around efficient drying of sand or other materials through the use of a rotating drum and hot air flow. The primary goal of a sand rotary dryer is to reduce the moisture content of the material to a level suitable for its intended use. Here are the key design principles of a sand rotary dryer:

Advanced design: Tongli Sand rotary dryer the overall length is 60% shorter than that of a single-cylinder dryer, which is conducive to process layout. Reduce the building area of the plant, save about 40% of the project investment.

Rotating Drum: The core component of a sand rotary dryer is a rotating drum or cylinder. This drum is inclined slightly from the horizontal and rotates on its axis. The material (in this case, sand) is fed into one end of the drum and moves slowly towards the discharge end due to the rotation.

Heat Source: A heat source is required to provide the energy necessary for drying. This is  achieved by introducing hot air or combustion gases into the rotary dryer. Common heat sources include natural gas burners, coal-fired furnaces, or even waste heat from other industrial processes.

Conduction: The wet quartz sand comes into direct contact with the hot surfaces inside the rotary dryer, which are heated by various heat sources. Conduction facilitates the transfer of heat from the hot surfaces to the material, leading to moisture evaporation.

Convection: As the wet quartz sand rotates inside the dryer, it is exposed to a stream of hot air or gases. This convective heat transfer helps in carrying away the evaporated moisture from the material surface, maintaining a concentration gradient that promotes continuous drying.

Radiation: In addition to conduction and convection, thermal radiation plays a role in heat transfer. The hot surfaces emit infrared radiation, which is absorbed by the wet material, further contributing to the heating process.

Flights or Lifters: Flights or lifters are attachments mounted on the interior surface of the drum. They help to lift and cascade the material as the drum rotates. This movement exposes the material to the hot air, ensuring even and efficient drying by maximizing the contact between the material and the hot air.

Material selection: Tongli Sand rotary dryer adopts heat-resistant and wear-resistant alloy steel plate, which is 4 times more wear-resistant than ordinary steel plate. Long service life and easy maintenance.

Efficiency: Tongli Sand rotary dryer features thermal efficiency, the outer barrel temperature is lower than 60 degrees (the single-cylinder dryer outer barrel temperature is as high as 150 degrees), the outlet temperature is low, and the discharge temperature is lower than 60 degrees.

Scalability: Tongli Sand 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.

Specifications of sand rotary dryer

Note: *The initial moisture is assumed to be 2~6% and final moisture is 1~4%; Inlet temperature of hot air is 150~250 Celsius and outlet temperature is 70~90 Celsius; Production Capacity will vary according to the composition and moisture of the material.

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Industry Knowledge extension

What is the application of quartz sand?

Dried quartz sand, also known as silica sand or industrial sand, has a wide range of applications due to its unique properties. Here are some common applications of dried quartz sand:

Construction: Dried quartz sand is used in construction as a key component in concrete and mortar mixtures. Its high silica content contributes to the strength and durability of concrete.

Glass Manufacturing: One of the most significant uses of quartz sand is in the production of glass. It is a primary ingredient in glassmaking, contributing to the clarity, strength, and thermal resistance of glass products.

Foundry Casting: Quartz sand is used in foundries to create molds and cores for metal casting. Its high refractory nature makes it suitable for withstanding the high temperatures of molten metals.

Ceramics and Pottery: In the ceramics industry, dried quartz sand is added to clay formulations to enhance the strength and firing properties of ceramic products.

Water Filtration: Quartz sand is used as a filter media in water treatment and purification processes. It effectively removes impurities, sediments, and suspended particles from water.

Oil and Gas Industry: In the oil and gas industry, quartz sand is used as a proppant in hydraulic fracturing (fracking). It helps keep fractures open and allows the extraction of oil and gas from underground reservoirs.

Electronics and Semiconductors: Quartz sand is used in the production of silicon wafers for the semiconductor industry. The high purity of quartz is crucial for the manufacturing of integrated circuits and other electronic components.

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.