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Graphite heat exchanger
- 2019-12-10-

1,Graphite heat exchangerstructure
The base of the graphite heat exchanger is a cylinder with a hole with a diameter of 350mm in the middle, which turns the cylinder into a cylinder (see Figure 1). The cylinder has relatively stable structural strength, easy to seal, no cement is needed in the structure, and PTFE O-ring sealing medium is selected, and a pressure spring is installed as an active compensation mechanism for thermal expansion and contraction. The lower part has medium redistribution. Room, enhanced turbulence effect, high structural strength, strong heat and pressure resistance, good impact resistance, high volume utilization, high heat transfer efficiency, and easy maintenance.
2. Working principle of graphite heat exchanger
Graphite not only has acid corrosion resistance, but also has good heat conduction function. The graphite core is made into a block-hole structure separated from each other vertically and horizontally. When the two media pass through each other, the high-temperature medium continuously transfers heat to the graphite for heat exchange. The low-temperature medium continuously gets heat from the heat exchanger, thus realizing heat exchange.

3. Advantages and disadvantages of graphite heat exchanger
Advantages: 1. Corrosion resistance: Suitable for non-oxidizing or weakly oxidizing strong acids, alkalis, salt solutions, most organic solvents and composite media of organic acids.
2. High thermal conductivity: thermal conductivity is higher than many metals, second only to copper and aluminum, 2 times larger than carbon steel, 5 times larger than stainless steel, ranking first among non-metallic materials, suitable for making various heat exchange equipment
3. Small linear expansion coefficient, high temperature resistance, heat shock resistance.
4. The appearance is not easy to scale and no pollution.
5. Good mechanical processing function.
6. Low density and light weight.
Defects: Graphite heat exchangers are divided into two types: block-hole type and shell-and-tube type. The main defect of the block-hole graphite heat exchanger is that once leakage occurs, it is difficult to find and repair. The defect of the shell-and-tube graphite heat exchanger is that the strength of the graphite tube is relatively low, and the steam pressure used cannot exceed 0.15MPa; the flow rate of the heated medium is low and can only be controlled at 2 to 3m/s; the temperature difference between the inlet and outlet can only be controlled within 2~4℃, the heat exchanger has a large volume.
4. Use of graphite heat exchanger
Based on the above advantages, graphite heat exchangers are increasingly used in cold-rolled pickling lines, chemical, petroleum, and pesticide industries.
This article mainly introduces the use of graphite heat exchanger in the pickling line. In the cold-rolling pickling process, the graphite heat exchanger pumps acid out from one end of the acid tank through an acid pump, pumps it into the graphite heat exchanger, and is heated by the graphite heat exchanger and discharged back to the other end of the acid tank, because this process is Continuously, so the graphite heat exchanger can heat the acid

The graphite heat exchanger changes the heating method of the acid, makes the acid temperature rise uniformly, shortens the temperature rise time, reduces steam consumption, reduces energy waste, and improves work efficiency; graphite heat exchanger increases the fluidity of the acid, The surface of the strip produces a certain scouring effect, which accelerates the process of removing the scale. Compared with the heating method of direct steam heating of the acid solution, because of the change of the heating method, the overheated volatilization of the acid and the dilution of the acid by the condensed water are significantly weakened, and the acid consumption benefit is significantly reduced.