What are the requirements for the design of spiral plate heat exchangers
One end of the tube sheet of the spiral plate heat exchanger is fixed to the shell, while the other tube sheet can float freely in the shell. The shell and tube bundle are free to expand. Therefore, when the temperature difference between the two media is large, the tube bundle There is no thermal stress between the shell and the shell.
The floating head end is designed as a detachable structure, so that the tube bundle can be easily inserted or drawn out of the shell. This provides convenience for inspection and cleaning. However, the structure of the heat exchanger is more complicated, and the floating end small cover cannot know the leakage situation during operation. Therefore, pay special attention to its seal during installation.
The hook ring plays an important role in ensuring the sealing of the floating head and preventing the leakage between the media. With the development of the design and manufacturing technology of the head heat exchanger, and the accumulation of long-term use experience, the structure of the hook ring has also been improved and perfected.
The tube of the heating heat exchanger constitutes the heat transfer surface of the heat exchanger, and the size and shape of the tube have a great influence on heat transfer. When a small diameter tube is used, the heat exchange area per unit volume of the heat exchanger is larger, the equipment is more compact, the metal consumption per unit heat transfer area is small, and the heat transfer coefficient is also higher. However, it is troublesome to manufacture, and the tube is easy to scale and difficult to clean. Large diameter pipes are used for fluids with high viscosity or dirty, and small diameter pipes are used for cleaner fluids.
The arrangement of the tubes of the heat exchanger on the tube sheet not only considers the compactness of the equipment, but also considers the nature of the fluid, structural design, and processing and manufacturing. There are four scale arrangements of tubes on the tube plate: equilateral triangle and corner equilateral triangle arrangement, which are used together with shell side media cleaning and do not require mechanical cleaning. The square and corner square arrangement can make the small bridge between the tubes form a straight channel, which is convenient for mechanical cleaning. It is generally used for the occasions where the tube bundle can be drawn out of the tube for cleaning.