As a double tube plate heat exchanger is mainly used for high temperature and high pressure, inflammable, explosive, toxic or heat exchanger under the condition of strong corrosive medium, for a better application, must grasp the design, manufacture, operation and maintenance, which is very important is double tube plate in manufacturing quality is better, to demand higher manufacture precision, at the same time, the quality of heat exchange tube is better, ensure that in use do not appear so the heat exchange tube wall rupture.
1. Double tube plate heat exchanger using matters needing attention
(1) when the tube side and shell side after two medium mixture can cause severe corrosion;
(2) side to extreme or highly harmful medium seep into the other side will cause serious consequences;
(3) when the tube side and shell side media mix two kinds of media will cause the combustion or explosion;
(4) when a medium into another medium, cause catalyst poisoning;
(5) tube side and shell side causes polymerization or generated after media mix resin material;
After 6 tube side and shell side media mix will cause chemical reaction to terminate or restrict;
7) after the tube side and shell side media mix, cause product contamination or the decrease of the quality of the product.
2. The structure of the double tube plate heat exchanger
Adopts fixed tube plate structure, double tube plate heat exchanger tube bundle can't take out cleaning, this is the single tube plate heat exchanger can use a variety of structural type, tube bundle can be cleaned out a different place.
For larger temperature difference between the double tube plate heat exchanger, shell can be mounted on the bellows expansion joint;
In addition to consider the single tube plate heat exchanger on the cylinder with bellows expansion joint, often using floating head or u-shaped tube type to compensate.
For double tube plate heat exchanger, there are two kinds of the understanding of the design concept: a think double tube plate heat exchanger used in absolutely prevent medium to mix between the shell side of the pipe string, design in the cavity between the internal and external tube plate with drainage deluge valve, for everyday observation and tube plate leakage emissions, makes the shell side of the tube medium to be inside and outside the tube plate isolation on the second floor.
This is the main purpose of the double tube plate structure.
Another think double tube plate heat exchanger can be used in the shell side of the pipe between the medium pressure difference is very big, the design in the cavity between the inner and outer tube plate with a medium, to reduce the pressure difference of the medium between the shell side of the tube.
This as the common single tube plate heat exchanger, and can't absolutely guarantee on the tube plate nozzle is not leak.
Double tube plate isolation between the cavity is the main difference with single tube plate heat exchanger structure, the isolation chamber is not connect with the tube side and shell side, not under medium pressure, but under mechanical load and thermal load of the equipment.
The bearing capacity of the isolation chamber depends primarily on the double tube plate spacing.
On the shell side of the fixed double tube plate for hydrostatic test, the inside of the tube plate and the heat exchange tube joint there may be a leak, so must be taken into account in determining the spacing between the double tube plate the minimum space required for observation, leak detection.
