Graphite heat exchangers are heat exchangers made of
impregnated impervious graphite or press moulding impervious
graphite.
Structure
Graphite heat exchangers can be divided into block type, shell
type and plate type according to their structure.
Block hole type: It is assembled from a number of massive
graphite components with holes.
Shell and tube type: shell and tube heat exchanger occupies an
important position in the graphite heat exchanger, according to
the structure is divided into fixed and floating head.
Plate type: Plate heat exchangers are made by bonding graphite
plates. In addition, there are immersive, spray-type and
sleeve-type (see snake-tube heat exchanger, casing heat
exchanger).
The plate heat exchanger is a new type of high-efficiency heat
exchanger formed by stacking a series of metal plates with a
certain corrugated shape. A thin rectangular channel is formed
between the various plates, and heat exchange is performed
through the half plate. Plate heat exchanger is the ideal
equipment for liquid-liquid, liquid-gas heat exchange. It
features high heat exchange efficiency, small heat loss,
compact and lightweight structure, small footprint, easy
installation and cleaning, wide application and long service
life. Under the same pressure loss condition, the heat transfer
coefficient is **5 times higher than that of the tubular heat
exchanger, covers an area of one-third of the tube heat
exchanger, and the heat recovery rate can be as high as more
than *0%.
Feature
The graphite heat exchanger has good corrosion resistance, the
heat transfer surface is hard to scale, and the heat transfer
performance is good. However, graphite is fragile, low in
bending strength and tensile strength, and therefore can only
be used for low pressure. Even though the block-shaped
structure with the best pressure bearing capacity, the working
pressure is generally only 0.**0.5 MPa. Graphite heat
exchangers are expensive, bulky. It is mainly used for heat
exchange of corrosive media such as hydrochloric acid, sulfuric
acid, acetic acid and phosphoric acid, such as condensers for
acetic acid and acetic anhydride.
Graphite pipes are classified into synthetic resin
impregnation, water glass impregnation, and asphalt
impregnation according to the impregnated materials.
