More and more stainless steel boiler tubes are used in heat exchangers

Stainless steel boiler tube in the tube (also called tube shell, row tube type) heat exchanger more USES, a large number of pipes!It has a long history of industrial application and still dominates all heat exchangers.The tubular heat exchanger is mainly composed of shell, tube bundle, tube plate and seal head. The shell body is mostly round with parallel tube bundle inside. Both ends of the tube bundle are fixed on the tube plate.

Two kinds of fluid that heat is exchanged in a tubular heat exchanger.A flow outside a tube whose stroke is called a shell stroke.The wall surface of the tube bundle is the heat transfer surface.In order to improve the heat transfer coefficient of the fluid outside the pipe, a certain number of transverse baffles are usually installed in the shell.The baffle can not only prevent the short circuit of the fluid and increase the fluid speed, but also force the fluid to cross the pipe multiple times according to the prescribed path, which greatly increases the turbulent degree.There are two kinds of commonly used baffles, circular and disk, the former is more widely used.Every time a fluid passes through the tube bundle is called a pipe path, and every time it passes through the shell is called a shell path.In order to improve the speed of the fluid in the pipe, an appropriate baffle can be set up inside the sealing heads at both ends to divide all the pipes into several groups on average.In this way, the fluid can travel back and forth from the bundle several times at a time through only part of the pipe, known as the multi-pipe process.Similarly, in order to improve the external velocity of the pipe, a longitudinal baffle plate can be installed in the shell to allow the fluid to pass through the shell space several times, which is called multi-shell process.In a tubular heat exchanger, the temperature of the shell and the tube bundle is also different due to the different fluid temperature inside and outside the tube.

Fixed stainless steel boiler tube plate type

Fixed tubular plate heat exchanger is to weld the two ends of the tube plate directly to the shell.It is mainly composed of shell, tube plate, tube bundle, seal and other main components.There is a pipe bundle in the shell. The two ends of the pipe bundle are welded, expanded or expanded welded, and some methods are adopted to fix the pipe on the pipe plate.Fixed tube plate heat exchanger is simple in structure, low in cost, easy to manufacture, easy to clean and repair, but difficult in shell process.When there is a large temperature difference between the heat exchanger pipe and the shell, there should be an expansion joint on the shell.

Floating-head type

One end of the floating head heat exchanger is fixed between the shell and the box, and the other end can move freely in the shell, that is, the shell and the tube bundle can expand freely.Therefore, there is no temperature difference stress between the pipe bundle and the shell.Generally, the float head can be disassembled, and the pipe bundle can be drawn and loaded freely.The structure of floating head heat exchanger can be used in the case of large temperature difference between pipe bundle and shell.The cleaning and maintenance of pipe bundle and shell are more convenient, but its structure is relatively complex and the requirements for sealing are high.

Stainless steel boiler tube "U" type tube for tubular heat exchanger

The u-tube heat exchanger is a u-shaped heat exchanger with two ends fixed on the same tube plate.Because the shell is separated from the heat exchange pipe, the heat exchange pipe bundle can freely expand and expand, without temperature difference stress due to the temperature difference of the medium.The u-tube heat exchanger has only one tube plate, no floating head and simple structure.Tube bundle can extract and load of freedom, convenient cleaning, possesses the advantages of floating head heat exchanger, but because of the heat exchange tube radius of u-shaped bending, the outermost layer heat exchange tube can be replaced after damage, other pipe damage only blocking pipe.At the same time, compared with the fixed tubular plate heat exchanger, because the heat exchanger tube is limited by the bending radius, there is a gap in the center of the tube bundle, the fluid is easy to short-circuit, which affects the heat transfer effect.