1. Feed machinery and equipment accessories press roller assembly product introduction
In the pelletizing process of feed production, the press roll assembly is one of the key components of the pelletizing machine. It works closely with the press die to exert pressure on the feed raw materials to form pellets through the die holes of the press die. The performance of the press roll assembly directly affects the quality of feed particles, the pelleting efficiency and the overall stability of the pelleting machine.
2. Structure composition
Roll body
The roller body is usually cylindrical, and its outer surface is in direct contact with the feed material and exerts pressure. The diameter and width of the roller body are determined according to the type and production requirements of the granulator, generally between 100-300 mm in diameter and 50-200 mm in width. The surface roughness of the roller body is low to reduce the friction between it and the feed raw materials, and its cylindricity and coaxiality need to be strictly controlled to ensure that the pressure of the feed raw materials can be evenly applied during the rotation process to ensure the molding quality of the pellet feed. In the interior of the press roll body, there is usually a shaft hole for installing the press roll, and the interference fit or key connection between the shaft hole and the press roll is adopted to ensure the connection between the press roll body and the press roll and the synchronous rotation.
Press roll shaft
The press roller is the core supporting part of the press roller assembly, which undertakes the dual tasks of transmitting torque and supporting the press roller body. The material of the press roller is generally selected as high-strength alloy steel, such as 40Cr, 42CrMo, etc., to ensure that it has sufficient strength and stiffness to withstand the pressure and torque during the granulation process. The two ends of the roller are usually designed with bearing mounting positions for mounting bearings through which the roller assembly is mounted on the body of the granulator and ensures that the roller can rotate flexibly. At one end of the roller, there may also be a keyway or other connection structure for connecting with the transmission device to receive power from the motor or reducer and rotate the roller around the shaft.
Bearing and bearing seat
Bearing is the key part of the press roller assembly to ensure the flexible rotation of the press roller, the common bearing types are deep groove ball bearings, cylindrical roller bearings and so on. Deep groove ball bearing is suitable for bearing small radial load and a certain axial load, has a high speed capacity, in some small granulators or high speed requirements of the application of more; Cylindrical roller bearings have a large radial load capacity, suitable for large granulators or high radial load requirements. The bearing seat is used to install the bearing and fix the bearing to the body of the pelletizer, whose structure needs to ensure the installation accuracy and stability of the bearing, while being able to withstand the vibration and impact force generated during the pelleting process. Bearing housing is generally made of cast iron or cast steel material, with good shock absorption and strength.
Sealing device
In order to prevent feed raw materials, dust and other impurities from entering the bearing, affecting the normal lubrication and service life of the bearing, the press roll assembly is provided with a sealing device. The sealing device usually includes an oil seal, a sealing ring and other components, which are installed between the press roll and the bearing seat and the gap between the press roll body and the press roll. The oil seal is generally made of rubber material, has good elasticity and sealing performance, and can effectively block the entry of impurities; The sealing ring can be made of rubber or other polymer materials, which can be selected according to different sealing requirements. The good performance of the sealing device is one of the important factors to ensure the stable operation of the press roll assembly, which can reduce the maintenance cost and downtime of the equipment.
Regulating device
The press roll assembly is also usually equipped with a regulating device to adjust the gap between the press roll and the die. The gap between the roller and the die directly affects the molding quality and pelleting efficiency of feed particles. The adjustment device is generally realized by screw, nut, hand wheel or hydraulic system and other components. According to the characteristics of feed materials, production requirements and other factors, the operator can precisely adjust the gap between the roller and the die by adjusting the device. For example, when producing feed pellets of different sizes, the gap size needs to be adjusted accordingly; When the humidity of the raw material is large or hard, it is also necessary to adjust the gap appropriately to ensure the smooth progress of the granulation process.
3. Material characteristics
Press roller body material
The material of the roller body needs to have high wear resistance, hardness and certain toughness. Commonly used materials are alloy cast iron and alloy steel. Alloy cast iron such as high chromium cast iron, containing a high proportion of chromium element, after special heat treatment, the surface hardness can be as high as HRC50-60, with strong wear resistance, can effectively resist the wear and corrosion of feed raw materials, suitable for the treatment of various hardness and properties of feed raw materials, widely used in the feed pelletizing industry. Alloy steel materials such as 42CrMo, after tempering and surface quenching treatment, the surface hardness can reach HRC45-55, which has good comprehensive mechanical properties, while ensuring wear resistance, but also has a certain toughness, can withstand the impact load in the pelletizing process, not easy to break or break, in some occasions with higher requirements for roller performance, Such as large feed granulator or processing special feed formula use.
Press roller material
As mentioned earlier, the press roller is generally made of high-strength alloy steel, such as 40Cr, 42CrMo, etc. After the tempering treatment, the hardness of 40Cr alloy steel can reach HB241-286, which has good strength and toughness, and can meet the performance requirements of the general pelletizing machine press roller. 42CrMo alloy steel has more advantages in strength and hardenability, after tempering and surface quenching treatment, the surface hardness can be increased to HRC50-55, in large, heavy duty granulator, can better withstand large torque and radial force, to ensure that the press roll in a long time, high strength working conditions stable and reliable operation, Reduce equipment failure due to shaft deformation or damage.
Bearing and bearing seat material
Bearing material is usually used bearing steel, such as GCr15, bearing steel has high hardness, high wear resistance and good fatigue life characteristics, to ensure that the bearing in high-speed rotation and bearing a certain load under the case of stable work. Bearing housing is generally made of cast iron or cast steel. Cast iron bearing seat such as gray cast iron HT200, HT250, etc., has good shock absorption, casting performance and cutting performance, relatively low cost, suitable for general granulator; Cast steel bearing housing such as ZG230-450, ZG270-500, etc., higher strength and toughness, can withstand greater impact force and vibration, in large or heavy duty granulator more applications, can effectively protect the bearing and other parts of the press roll assembly, improve the overall reliability of the equipment.
Seal material
The oil seal and sealing ring in the sealing device are mainly made of rubber or polymer materials. Rubber material such as nitrile butadiene rubber (NBR), has good oil resistance, wear resistance and elasticity, can adapt to the feed production environment of grease, dust and other conditions, effectively prevent impurities into the bearing; Fluororubber (FKM) has better resistance to high temperature and corrosion, and is suitable for pelletizing machines working in high temperature environments or occasions dealing with corrosive feed raw materials. Polymer material sealing rings, such as polyurethane (PU) sealing rings, have high strength, wear resistance and aging resistance, and are also used in some press roll assemblies with high sealing performance requirements.
4. Performance characteristics
Efficient extrusion capacity
Through the tight fit between the press roll and the die, strong pressure is applied to the feed raw material, so that it can smoothly pass through the die hole of the die, forming feed particles with regular shape and uniform density. Factors such as the material, surface roughness and the adjustment of the gap between the roll body and the die have important effects on the extrusion capacity. For example, the high hardness and low surface roughness of the roller body can better transfer the pressure to the feed raw materials and improve the molding quality of the particles; The precisely adjusted gap between the roll and the die ensures that feed materials of different types and characteristics can be properly squeezed, improving the pelletizing efficiency. In large feed pelleting production lines, the efficient press roller assembly can quickly process a large number of powdered feed raw materials into pellets to meet the needs of the market.
Good wear resistance and durability
Because in the pelleting process, the press roll assembly needs to be in contact with the feed raw material for a long time and withstand great friction and pressure, so good wear resistance is an important performance characteristic. The roller body adopts alloy cast iron, alloy steel and other materials as well as surface treatment technology, so that it can effectively resist wear and reduce surface loss. At the same time, the material selection and manufacturing process of the roller, bearings and other components also ensure their durability under high load working conditions. For example, after processing a large number of feed raw materials, the high chromium cast iron roll body can still maintain a good surface shape and dimensional accuracy, reducing the frequency of replacing the roll assembly, reducing the maintenance cost of the equipment, and improving the utilization rate of the production equipment.
Stable operating performance
The bearing, sealing device and regulating device in the press roll assembly together ensure its stable operating performance. High-quality bearings can ensure that the roller is flexible and smooth during rotation, reducing vibration and noise; The sealing device effectively prevents the entry of impurities, protects the bearing and other components, and avoids the failure caused by impurities; The adjusting device can precisely adjust the gap between the press roll and the die according to the production demand to ensure the stability of the pelleting process. In the feed pelletizing process, the stable operation of the press roller assembly ensures the consistent quality of the feed particles produced, reduces downtime caused by equipment failures, and improves production efficiency and product quality stability.
5. FAQ
Q: What is the main material of the press roll assembly?
A: The press roll assembly is usually made of high-strength steel or alloy steel to ensure that it has sufficient strength and wear resistance. These materials can withstand high loads and long periods of use.
Q: What are the surface treatment processes of the press roll assembly?
A: The common surface treatment process of the press roll assembly includes quenching, carburizing and nitriding. These processes can improve the hardness and wear resistance of the surface and extend the service life.
Q: How to ensure the transmission efficiency of the press roll assembly?
A: In order to ensure the transmission efficiency of the press roller assembly, the coordination accuracy between the shaft and the press roller should be ensured, and the lubrication system should be checked and maintained regularly to keep the lubricating oil clean and appropriate.
Q: How long is the replacement cycle of the press roll assembly?
A: The replacement cycle of the press roll assembly depends on the frequency of use, the working environment and the operating condition of the equipment. In general, when significant wear, deformation or inability to effectively drive is found, a new press roll assembly should be considered.
Q: What are the special requirements of the press roll assembly in different application scenarios?
Answer: In different application scenarios, the press roll assembly may have different special requirements. For example, the press roll assembly used in high temperature environments needs to have high temperature resistance; For use in corrosive environments, corrosion-resistant materials are required.
