As a high-performance heat exchanger, carbon fiber composite tubular graphite heat exchanger combines the advantages of carbon fiber composite materials and graphite materials, and has broad application prospects in the fields of chemical industry, energy, etc. Its manufacturing process is complex and delicate, and multiple key steps are required to ensure product performance.
The first step in manufacturing carbon fiber composite tubular graphite heat exchanger is material pretreatment. Carbon fiber needs to be pre-impregnated in thermosetting resin (such as phenolic resin, furan resin) to form a uniform composite material. The combination of resin and carbon fiber is achieved through an impregnation process, and then a curing agent is wrapped on the fiber surface to form a strong chemical bond through chemical reaction to prevent fiber fluffing. This step lays the foundation for the mechanical properties of the composite material.
Composite tube molding is the core link of the manufacturing process. The cured carbon fiber is heated to a viscous flow state, and it is wrapped on a core mold or graphite tube through a winding process to control the winding thickness (usually 10mm to 20mm or more). During the winding process, it is necessary to ensure that the fibers are evenly arranged to avoid gaps or stress concentration. After demolding, the composite tube is initially formed, and its structural strength and dimensional accuracy directly affect the subsequent performance.
In order to improve the thermal conductivity and corrosion resistance of the composite tube, it is necessary to carry out high-temperature graphitization treatment. The composite tube is placed in an inert atmosphere and heated to 1000℃ to 2800℃ to make the material undergo graphitization transformation. This process can significantly improve the thermal conductivity of the material and enhance its chemical stability. After high-temperature treatment, the internal structure of the material is more compact and suitable for high temperature and high pressure conditions.
After the composite tube is formed, the structure needs to be assembled. The two ends of the carbon fiber heat exchange tube are positioned through the auxiliary tube sheet, and the mechanical seal with the tube sheet is achieved by bonding process or O-ring. The adhesive must be compatible with the composite tube material to ensure sealing. During the assembly process, the baffle needs to be installed inside the jacket in an offset manner to increase the residence time of the shell-side fluid and improve the heat exchange efficiency.
Sealing treatment is the key to ensuring the safe operation of the equipment. When using O-rings, high temperature and corrosion resistant rubber materials (such as FKM, FFKM) must be selected, and the sealing must be achieved by screwing. The bonding process requires controlling the amount of adhesive and curing conditions to ensure bonding strength. Sealing performance directly affects the service life and reliability of the equipment.
After assembly, the heat exchanger needs to be fully tested for performance. This includes pressure testing (to verify sealing), thermal conductivity testing (to evaluate heat exchange efficiency), corrosion resistance testing (to simulate actual working conditions), etc. The test results must meet the design standards to ensure the stability of the equipment under extreme conditions such as high temperature, high pressure, and strong corrosion.
To improve the durability and aesthetics of the equipment, surface treatment is required. Spraying anti-corrosion coating or polishing process can be used to reduce the erosion of the material by the medium. The surface treatment needs to match the material properties to avoid affecting the heat exchange efficiency.
The manufacturing process of carbon fiber composite tubular graphite heat exchanger integrates multidisciplinary technologies such as materials science, thermodynamics, and mechanical engineering. Through strict quality control and technological innovation, efficient and reliable heat exchange performance can be achieved to meet the dual needs of modern industry for energy conservation and emission reduction and equipment safety.
