A heat exchanger is an energy-saving and environmentally friendly equipment that maintains heat transfer from raw materials between two or more fluids at different temperatures. It transfers heat from fluids with higher temperatures to fluids with lower temperatures, ensuring that the fluid temperature meets the required standards for processing technology. Additionally, it is one of the key machinery and equipment for improving the utilization rate of electrical energy. But many people don't know the difference between single tube plate and double tube plate heat exchangers. Below, the editor will share it with you.

A heat exchanger is an energy-saving and environmentally friendly equipment that maintains heat transfer from raw materials between two or more fluids at different temperatures. It transfers heat from fluids with higher temperatures to fluids with lower temperatures, ensuring that the fluid temperature meets the required standards for processing technology. Additionally, it is one of the key machinery and equipment for improving the utilization rate of electrical energy. But many people don't know the difference between single tube plate and double tube plate heat exchangers. Below, the editor will share it with you.

The isolation chamber between the double tube plate is the primary difference from the single tube plate structure. This isolation chamber is not connected to the tube side or shell side, and does not bear medium pressure, but bears the mechanical and thermal loads of the equipment. The load-bearing capacity of the isolation chamber primarily depends on the spacing between the double tube plates. When conducting a shell side hydrostatic test on a fixed double tube plate, there may be leakage at the connection between the inner tube plate and the heat exchange tube. Therefore, it is necessary to consider the minimum space required for inquiry and leak detection when determining the spacing between the double tube plates.

Compared to single tube plates, double tube plates have a much lower probability of leakage between the tube and shell sides; The stress situation is better. From a structural perspective, the double tube plate adopts a fixed tube plate structure, which cannot be removed for cleaning. Practical application shows that the double tube plate heat exchanger manufactured by mechanical expansion method can meet the requirements of application.

Structural comparison:

The double tube plate heat exchanger adopts a fixed tube plate structure, which cannot be pulled out for cleaning. The single tube plate can be selected from various structural types, which can be pulled out for cleaning. For double tube plate heat exchangers with large temperature differences, corrugated expansion joints can be installed in simplified Chinese; For single tube plates, in addition to considering the installation of corrugated expansion joints on simplified structures, floating heads or U-shaped tube types are often used for compensation.

There are two planning concepts regarding the double tube plate heat exchanger: one believes that the double tube plate heat exchanger is used to prevent the mixing of media between the tube and shell sides, and plans to install a drainage and pouring valve on the cavity between the inner and outer tube plates for daily investigation and discharge in case of leakage from the inner tube plate, so that the media in the tube and shell sides are effectively isolated by the outer and inner tube plates. This is the primary purpose of selecting the double tube plate structure type. Another view is that double tube plate heat exchangers can be used in situations where there is a large pressure difference between the medium and the shell side. It is planned to involve a medium in the cavity between the inner and outer tube plates to reduce the pressure difference between the medium and the shell side. This is the same as a typical single tube plate, and it cannot be guaranteed that the pipe opening on the outer tube plate will not leak.

Comparison in application:

Single tube plates are common. In addition to the frequent occurrence of gasket bolt flange joint sealing leakage in application, there may also be leakage at the pipe mouth on the pipe plate, as well as welding cracks. Most of the leakage from the pipe openings on the tube plate occurs at the welding arc stop. The gas was not completely released during the welding arc, resulting in sand holes.

Double tube plate has a double-layer tube plate on the surface and inside, assuming that the inner tube plate mouth leaks, and there is also outer tube plate protection. Cracks in the welding of single tube plates often occur at the small end of the cone of the large flange of the heat exchanger's simplified body and the joint of the simplified body. The primary reason for the problem here is that the stress at the joint between the small end of the large flange cone and the simplified body is high; The second is a sudden change in specifications and shape, which briefly buries defects.