The design of the special vulcanizing machine for rubber conveyor belts should revolve around the core requirements of the vulcanization process, involving multiple aspects such as structure, heating, pressure control, and safety. The following is a specific analysis:
Structural design
Frame and pressure-bearing components: The frame design must have high strength and rigidity to withstand the tremendous pressure during the vulcanization process. The frame of the main beam can be customized with an internal screw type according to customer requirements to enhance structural stability. Pressure-bearing components such as vulcanizing drums should be made of materials that can withstand high-pressure steam. Steam should be passed through the interior for heating, and the temperature can be controlled and adjusted according to the vulcanization conditions. The outer sleeve of the drum has a ring-shaped groove vulcanizing die with the same cross-sectional shape as the conveyor belt, which can be replaced according to different models of the conveyor belt.
Vulcanization chamber design: The vulcanization drum and the electric heating cover form an arc-shaped vulcanization chamber. The pressure belt woven with steel wire is tensioned and then pressed onto the conveyor belt blank placed in the annular groove of the vulcanization die. The vulcanizing machine meets the requirements of various vulcanization times. The vulcanizing drum is driven by a variable-speed transmission device and rotates together with the pressure belt to meet the conditions of the three elements of vulcanization (time, temperature and pressure).
Modularization and scalability: The design should take modularization into account to facilitate adjustments according to specifications such as the width and length of the conveyor belt. For instance, the combined vulcanizing machine is suitable for conveyor belts with a width of 4200mm. The length of the vulcanized adhesive tape can be freely spliced as single or multiple units as needed.
Heating System Design
Heating method selection: The vulcanizing machine is divided into three forms: electric heating, steam heating and heat transfer oil heating. Electric heating has the advantages of precise temperature control and rapid temperature rise. Steam heating is suitable for large vulcanizing machines. The heating is uniform but the temperature control is relatively complex. Heat transfer oil heating has the characteristics of good thermal stability and wide temperature control range.
Temperature control: A high-precision temperature control system must be equipped to ensure that the vulcanization temperature can be adjusted freely within the range of 0-200℃ and maintain temperature uniformity. For instance, the vulcanization temperature of the conveyor belt is generally set at 147-151℃, and the vulcanization time is usually around 20-30 minutes.
Design of Pressure Control System
Pressure generation and regulation: The pressure required for vulcanization is generated through the hydraulic system, which must have a stable pressure output and precise pressure regulation function. Precise pressure control can be achieved by using components such as relief valves and proportional valves.
Pressure synchronous control: For multi-hydraulic cylinder systems, it is necessary to achieve pressure synchronous control to ensure that all parts of the conveyor belt are evenly stressed during the vulcanization process. The pressure of each hydraulic cylinder can be monitored in real time through a closed-loop control system by using sensors and adjusted through control valves.
Design of Auxiliary Devices
Stretching device: As the circumference of the conveyor belt blank is gradually stretched and increased during the heat vulcanization process, it needs to reach the standard length by the end of vulcanization. Therefore, a stretching device is required. The stretching drum of the stretching device needs to rotate and move at any time to keep the billet in a tensioned state all the time.
Cooling system: After vulcanization is completed, the conveyor belt needs to be cooled. A water cooling system can be designed to control the water cooling time. For example, the time to cool from 145℃ to below 70℃ is 6 minutes.
Safety protection devices: including overload protection, leakage protection, over-temperature protection, etc., to ensure the safe operation of the equipment. For instance, the electric heating press adopts digital temperature control to control and display the temperature of the heating plate, and it also has the function of automatically identifying incorrect instructions and avoiding accidents caused by incorrect operations.
Operation and maintenance design
Operation interface: An intuitive and user-friendly operation interface is designed to facilitate operators in setting vulcanization parameters and monitoring the vulcanization process. It can be controlled by PC or manual mode, with reliable performance and a high degree of automation.
Maintenance convenience: The structural design of the equipment should take maintenance convenience into account, such as easily disassembled heating plates, hydraulic cylinders and other components, to facilitate the daily maintenance and troubleshooting of the equipment.