The graphite heat exchanger can be divided into 3 types: block hole type, tubular shell type and plate type structure. Block hole type: assembled from a number of large bore graphite assemblies with holes. Shell: shell and tube heat exchanger in graphite heat exchanger occupies an important position, according to the structure is divided into fixed and floating head two. Plate type: plate heat exchanger is made of graphite plate bonded. In addition, there are immersion, spray and casing type (see snake tube heat exchanger, tube 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, the graphite is brittle and has low flexural and tensile strength, so it can only be used for low pressure. Even if the compressive strength is the best, the working pressure of the block is generally only 0.3 ~ 0.5 mpa. The graphite heat exchanger has high cost, large volume and little use. It is mainly used in the heat transfer of corrosive medium such as hydrochloric acid, sulfuric acid, acetic acid and phosphoric acid, such as condenser used for acetic acid and acetic anhydride.
The graphite tube is divided into synthetic resin impregnation, water glass resin impregnation and asphalt impregnation according to the different materials impregnated. 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, the graphite is brittle and has low flexural and tensile strength, so it can only be used for low pressure. Even if the compressive strength is the best, the working pressure of the block is generally only 0.3 ~ 0.5 mpa.
Block hole type: it is composed of several porous graphite elements with holes.
The shell and tube type: shell and tube heat exchanger in graphite heat exchanger occupies an important position, according to the structure is divided into fixed and floating head two.
Shell and tube heat exchanger (shell and tube heat exchanger) is also called tubular heat exchanger. The utility model relates to a wall heat exchanger with a wall surface closed in a tube bundle in a shell as a heat transfer surface. This kind of heat exchanger is simple in structure and reliable in operation. It can be made of various structural materials (mainly metal materials) and can be used at high temperature and high pressure. It is the most widely used type at present.
Board type: plate heat exchanger is made of graphite plate bonded. In addition, there are immersion, spray and casing type (see snake tube heat exchanger, tube heat exchanger).
Plate heat exchanger is a new type of high efficiency heat exchanger which consists of a series of corrugated metal sheets. Thin rectangular channels are formed between the plates, and heat exchange is carried out by halves. Plate heat exchanger is the ideal equipment for heat exchange between liquid, liquid and steam. The utility model has the advantages of high heat exchange efficiency, small heat loss, compact structure, light weight, small occupation area, convenient installation and cleaning, wide application, long service life, etc.. Under the same pressure loss, the heat transfer coefficient is 3-5 times higher than that of the tubular heat exchanger, and the floor area is 1/3 of the tubular heat exchanger, and the heat recovery rate can be as high as 90%.
