How to use a graphite heat exchanger
- 2019-11-16-

How to use graphite heat exchanger ? Nantong Golden Triangle Graphite Manufacturing Co., Ltd. tells you. When used as an evaporator, the tubular graphite heat exchanger must prevent the material from evaporating and crystallizing. Blocking the pipeline. The graphite heat exchanger must exhaust the air in the condenser when the cooling medium enters, otherwise it will easily cause graphite equipment to swell ( Especially at the tube sheet), leakage occurs! In the winter, after the work is completed, the cooling medium must be drained clean to prevent the equipment from cracking due to freezing ice. Generally, the cooling medium is used as the cooler, and the cooled medium is used later.

Tube and shell graphite heat exchangers must withstand the combined effects of radial and axial pressures (including tensile stress caused by temperature differences in different parts of the heat exchanger) generated by the medium inside and outside the tube in the operating state. Under the combined effect of these stresses, there are two types of failure of the heat exchanger: graphite tube is broken, and graphite tube blasts. These two forms account for a large proportion of tube and shell graphite heat exchanger damage. From the perspective of use, the failure mode of domestically produced graphite tubes is mainly broken, and the imported impregnated graphitized tubes are mainly blasted. When the tube of the heat exchanger is damaged, how to quickly repair it on the spot, the difficulty lies in how to quickly detect the leak of the graphite tube.

What to do if the graphite tube of graphite heat exchanger is damaged?

Water is poured into the tube side of the shell-and-tube graphite heat exchanger, so that the water level is about 50-100 mm higher than the end of the tube sheet on the heat exchanger. The water is drained quickly. At this time, the severely broken pipe will have vortices on the water surface of the upper tube sheet. You should quickly plug the upper port of the pipe with a rubber stopper and close the valve on the condensate drain pipe interface. Repeat the above operation to find out the severely broken pipe. Next, drain the water in the tube of the heat exchanger, and temporarily stop the leaked tubes. A 100mm long, M18 bolt is used on the outer sleeve of a pure rubber sleeve of 35.5mm / 18.5mm and a length of 60mm to form a # 1 expansion plug, which is inserted into the leaking pipe and the nut on the bolt is tightened. Due to the deformation of the rubber sleeve due to the axial pressure, it is tightly plugged in the tube to achieve the purpose of plugging.

When the shell-and-tube graphite heat exchanger is damaged, some tubes do not have fractures or too many large cracks, but only some small cracks. If they are not checked and blocked, leaks will occur when driving. For these slightly leaking graphite tubes, the following methods were used for leak detection.