Tongli rotary drum cooler Introduction

Tongli rotary cooler is a type of cooling equipment jointly developed by the compound fertilizer Institute and our factory. The cooling method adopts cold air counterflow, and the induced draft fan is used to draw cold air from the rear of the equipment to the material in reverse contact with the material for forced cooling, so that the material can be cooled rapidly. This equipment adopts a novel lifting plate structure, which changes the unreasonable cooling of bulk materials in the traditional cooling machine lifting plate structure. Therefore, the equipment has the characteristics of reasonable design, good cooling effect, stable operation, high output, and simple operation method, and is an ideal cooling device in compound fertilizer equipment.

Tongli rotary drum cooler structure

The rotary cooler is composed of, cooler shell, cooler riding ring, cooler girth gear, cooler transmission unit, cooler hood cover, cooler flights and so on. 

Cooler Shell: The rotary cooler shell is the main body of the cooler, 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.

Riding Rings(Tyre): The rotary cooler shell is supported on multiple riding rings usually 2~3, which are attached to the shell with point-welded padding on the inside. The rotary cooler riding rings allow the cooler to rotate smoothly on its axis and help distribute the cooler's weight. The thickness of the plate under the riding ring is increased to facilitate strength of the shell.

Girth Gear: The rotary cooler girth gear is a large gear ring encircling the cooler, usually mounted on the cooler shell. It is driven by a pinion gear, and together they form the primary drive unit to rotate the cooler. Under the girth gear is the spring plate, the function of the spring plate is to reduce heat transfer from the shell to the girth gear to prolong the service life time of the equipment.

Supporting Device: rotary cooler supporting device is composed of the supporting roller and thrust roller, the shaft is a forged object to prolong the service life time of the rotary cooler. One thing features about Tongli Supporting device is all the metal casting are produced by our own, the quality is guaranteed. All the metal casting supporting roller, metal casting thrust roller are machined and heat treated, the performance measure is reliable.

Cooler Hood Cover: The rotary cooler hood is located at the discharge end of the cooler and provides sealing to retain heat and gases. The rotary cooler 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.

Flights: The term "flights" in relation to a rotary cooler refers to the material lifters or fins that are attached to the internal rotating drum of the cooler. These flights play a crucial role in the cooling process by lifting and cascading the material through the heated air stream, enhancing heat and mass transfer for efficient drying.

Cooler transmission device: The transmission device of the rotary drum cooler 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 cooler, 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 cooler and the quality of the products being processed. Usually, the rotary cooler 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.

Tongli rotary drum cooler design principle

Heat Transfer Efficiency: The primary purpose of a Tongli rotary cooler is to transfer heat from the hot material to a cooling medium (usually air or water) in an efficient manner. To achieve this, maximize the contact area between the material and the cooling medium, often by using features like lifting flights or baffles inside the cooler drum. This enhances heat transfer and promotes even cooling.

Air Flow and Distribution: Proper air flow and distribution are crucial for effective cooling. The cooling air should be evenly distributed across the material bed to prevent dead zones or uneven cooling. Consider designing the internal structure of the cooler drum and the layout of the air distribution system to achieve uniform air flow.

Retention Time: The material should have sufficient time inside the cooler drum to achieve the desired cooling. Retention time is influenced by the cooler's dimensions, rotational speed, and the angle of inclination. Calculations based on material properties and cooling requirements will help determine the optimal retention time.

Material Movement and Mixing: The rotary motion of the cooler drum aids in mixing the material, which can lead to more efficient heat transfer. Proper flight design and drum inclination contribute to effective material movement and mixing.

Controlled Discharge: The cooled material should be discharged uniformly and without causing segregation. Design the discharge mechanism (e.g., adjustable baffles or discharge chutes) to prevent material buildup and ensure consistent product quality.

Insulation and Sealing: Insulation around the cooler drum can help minimize heat loss and increase energy efficiency. Additionally, effective sealing at entry and exit points prevents the ingress of ambient air, which could disrupt the cooling process.

Specifications of tongli rotary drum cooler

Note: * Diameter refers to the inner diameter.

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Zhejiang Tongli Heavy Machinery Manufacturing Co., Ltd (Formerly known as Tongxiang Coal&Mining Machinery Factory) established in year 1958 is a member of the Chinese National Building Material Machinery Association. Tongli is on the vendor list of designated production enterprise of the Ministry of Coal Industry. ISO9001、ISO14001、ISO45001 certified, accredited as High-tech & new technology enterprise of Zhejiang Province. With 65+ years of experience, Tongli has earned first class R&D and manufacturing capabilities, dedicated to provide satisfactory manufacturing equipments for global customers.   

Industry Knowledge extension

What is the application of rotary cooler?

Cement Industry: In the cement manufacturing plant, clinker (a heated mixture of raw materials) is produced in a kiln. This clinker is then passed through a rotary cooler to reduce its temperature before being transported to subsequent processing steps. The cooling process helps prevent the clinker from re-absorbing moisture and agglomerating, which could affect the quality of the final cement product.

Fertilizer Production: In the fertilizer production line, materials are often heated to create the desired chemical compounds. Rotary coolers are used to bring down the temperature of these materials to prevent agglomeration and ensure uniform distribution of nutrients.

Chemical Industry: Chemical reactions in various industrial processes often generate high temperatures. A rotary cooler can be used to cool down the reaction products or intermediates, ensuring that they are stable and can be further processed or packaged without degradation.

Metallurgical Industry: In metal smelting and refining processes, molten metal or alloys are often subjected to cooling to solidify them into a usable form. Rotary coolers can be employed to rapidly cool down the molten metal, enabling it to solidify uniformly and achieve desired material properties.

Food Processing: Certain food products, such as breakfast cereals and extruded snacks, are produced by cooking and extruding raw ingredients. A rotary cooler can be used to rapidly cool these products after the cooking process, preventing overcooking and maintaining their texture and flavor.

Biomass and Biofuel Industry: Biomass materials and biofuel pellets produced through processes like pyrolysis or torrefaction can be extremely hot. A rotary cooler can help lower the temperature of these materials to levels suitable for storage, transport, and subsequent processing.

Pharmaceutical Industry: Some pharmaceutical manufacturing processes involve heating and drying of intermediate products. Rotary coolers can be used to cool down these products before they are packaged or further processed into medications.

Petrochemical Industry: In the production of certain petrochemical products, such as polymers, cooling may be necessary to ensure that the material solidifies into the desired form. Rotary coolers can help control the cooling rate and prevent defects in the final product.

What is the difference between ball mill and vertical roller mill?

Both ball mills and vertical roller mills plays a vital role in the cement grinding plant. Ball mills are versatile and cost-effective, suitable for various materials and simple to maintain. On the other hand, vertical roller mills offer superior energy efficiency and particle size control, making them ideal for cement and ore grinding applications. The choice between the two depends on specific requirements, budget constraints, and technical expertise.