The heat transfer components are made of graphite heat exchanger. The graphite used in the manufacture of heat exchangers should be impermeable. Commonly used impregnated impermeable graphite and pressed impermeable graphite. According to its structure, graphite heat exchangers can be divided into three types: block type, shell-and-tube type and plate type. Block hole type: It is assembled from a number of block graphite components with holes (see the block hole type graphite heat exchanger).
Shell and tube type: Shell and tube heat exchanger occupies an important position in graphite heat exchangers. According to the structure, it is divided into two types: fixed type and floating head type. Plate type: The plate type heat exchanger is made by bonding graphite plates. In addition, there are immersion type, spray type and sleeve type, etc. (see Snake tube heat exchanger, sleeve heat exchanger). The graphite heat exchanger has good corrosion resistance, the heat transfer surface is not easy to scale, and the heat transfer performance is good. However, graphite is easy to brittle and has low bending and tensile strength, so it can only be used at low pressure. Even the block-shaped structure with the best pressure bearing capacity, its working pressure is generally only 0.3 to 0.5 MPa. Graphite heat exchangers are expensive, bulky, and not used much. It is mainly used for the heat exchange of corrosive media such as hydrochloric acid, sulfuric acid, acetic acid and phosphoric acid, such as the condenser of acetic acid and acetic anhydride.