Precautions for the use of graphite heat exchangers: It is strictly prohibited to operate over temperature and pressure during use, and sudden changes in temperature and pressure should be prevented. All valves should be opened slowly, and gradually adjusted to the maximum or minimum. When the steam is heated to prevent the violent impact of the steam, the equipment will rise slowly during operation. When the temperature of the graphite parts is averaged, the pressure will be increased slowly until the normal operation is reached. Pressure and the operation of the preheating process are very important. Operation steps: The cold carrier (material medium) should be passed through first, and the heat carrier (steam or hot water) should be passed through after the equipment is filled; the heat carrier (steam or hot water) should be stopped when the machine is stopped, and the cooling should be stopped after the equipment is cooled The carrier (material medium) checks the acidity and alkalinity of the condensate from time to time, analyzes the material composition of the tube side and the shell side regularly, and verifies whether the leakage occurs.
Clear the debris in the process pipeline before starting the graphite heat exchanger to prevent blockage of the graphite channels. Minimize the number of equipment startups and stops to extend the service life of the equipment. When the heat transfer of the equipment can be reduced, it should be stopped for inspection. If the equipment is severely scaled, it can be cleaned by appropriate physical or chemical methods; if the inside of the tube is blocked by crystals, it can be heated and melted for cleaning. Because graphite is a brittle material, mechanical methods are strictly prohibited. The highest (low) part of the shell is equipped with an exhaust (clean) pipe. Valves should be installed during the installation, and then the exhaust (clean) pipe should be connected. It is strictly forbidden to blindly die with a blind plate. Before using the equipment, open the drain valve on the top of the shell and close it after the air in the shell is completely removed. During operation, the non-condensable gas at the top of the shell side and the condensed water at the bottom must be discharged frequently.
The larger the particle size of the graphite base material, the smaller the volume density of the material and the lower the mechanical strength. The larger the holes between the particles, the more through holes may be exposed when drilling holes, and the porosity increases. In order to achieve the required compactness, the amount of impregnant will increase, which will affect the quality of impregnation and the thermal conductivity of impermeable graphite. The greater the density, the greater the mechanical strength. Therefore, using base materials with high bulk density (fine particles, grade B) to stop the immersion and heat treatment, the quality of the equipment for processing and consumption is stable and safe, and the application effect is good. The graphite heat exchanger impregnating agent fills the gaps in the graphite base material. The different types of impregnating agents will directly affect the corrosion resistance of impermeable graphite. The amount of immersion will affect the temperature and corrosion resistance of impermeable graphite. The impregnation vacuum is large and the pressure is high, which can reduce the number of impregnations, and the heat exchange effect is better than the traditional impregnation process (three times of impregnation, three times of heat treatment).