Shell and tube heat exchanger is one of the most common and practical methods of indirect heating and cooling of various fluids, which is mostly used in industrial environments, refineries and central heating systems. Due to the widespread use of heat exchangers in various industries, Seven central heating exchanger design company states the price of heat exchangers, heat exchanger standards and important principles in the production of shell and tube heat exchangers and everything you need to know to buy this group of equipment.
What is a tube shell heat exchanger?
Shell and tube heat exchanger is a set of cylindrical shell and fluid passage tubes that aim to increase or decrease the temperature of the fluid in the pipes in various industries such as refineries, power plants. , And the chemical industry
There are different types of heat exchangers, all of which aim to transfer heat between fluids, in some of which direct heat transfer and in others, such as shell and tube exchangers, it is done indirectly.
How the heat exchanger works
As mentioned, heat and temperature transfer in shell and tube exchangers is indirect and the passage of fluids through the shell and tubes causes a change in temperature in them. In the general structure of this group of heat exchangers, there is a shell or a cylindrical tank in which pipes are placed parallel to the shell circuit. A group of fluid that has the role of increasing or decreasing the temperature, enters the shell through a special inlet valve and indirect contact of the fluid entering the pipes inside the complex causes heat transfer. Finally, it is taken out of the fluid outlet valves with the desired temperature and is used for various purposes.
The direction of fluid passage in the shell and pipes may be aligned, misaligned, or intersecting, and the temperature difference between the shell and pipe fluids is the main reason for the temperature change, which prepares the fluid for different environments at a low cost.
Heat exchanger components
In the construction and production of shell and tube heat exchangers, regardless of the environment and the main purpose of its use, several important parts are considered, which in fact are the basis for the correct process of temperature change. The main components of heat exchangers are:
· Front head: Inlet of liquid or gas to the exchanger pipes
· Rear head: Fluid output from the exchanger
· Tube: A set of components for passing liquid or gas through pipes
· Shell: Tank and shell resistant to corrosion and pressure to pass temperature transfer fluid
The mentioned items are the general division of the internal structure of the shell and tube heat exchanger and its main components are:
· Tube or tube
· Tube plate
· Duct and duct cap
The shell is one of the most important components of the heat exchanger, which is made of carbon steel, brass and stainless steel in order to increase its resistance to pressure and corrosion. To increase the heat transfer efficiency inside the shell, plates called baffles are used, which is actually a kind of fluid flow conductor in the shell. Valves are used at the beginning and end to enter and exit the fluid into the shell.
The main fluid used in chemical and industrial processes enters copper or brass and steel pipes to reach the desired temperature, all of which are located inside the shell. The shape and structure of these pipes depend on the type of exchanger and are generally used in a curved or U-shaped and straight shape. One of the most important differences between shell and tube heat exchanger pipes is the number of screws and the direction of the fluid in them. For example, if the goal is for fluid to pass directly through the tube, straight, non-curved tubes are used. Conversely, if the goal is to increase the contact of the fluid inside the tube with the shell fluid, the maze will be greater. Based on the number of mazes of pipes inside the shell, the so-called 1 pass, 2 passes, etc. are said. One pass is the same as straight pipes, and as the number of passes increases, the number of mazes in the pipe will increase.
Types of shell-tube heat exchangers
The classification of heat exchangers is based on various factors, one of the most important of which is the shell and tube heat exchanger standards. Due to the fact that in the design and production of shell and tube exchangers, the TEMA standard is followed, as a result, there are exchangers in different classes and based on the desired environment, the most important of which are class R, C, B. Class R exchangers are mostly used in oil and gas refineries and Class B is produced for chemical projects and processes. Of course, it should be noted that according to this standard, heat exchangers are produced in different classes, each of which has different characteristics. Class A, B, C, D, E, F, G, H, etc. heat exchangers are among these.
In another division based on header or cap, this type of heat exchanger can be divided into the following groups:
Fixed tube sheet exchangers
In this group of exchangers, which are in class L, M and N, the fluid tubes are fixed on a plate called a tube sheet. Cost-effectiveness and simple construction and design in a short time is one of their most important features and they are in group 1 pass exchangers. In other words, in the construction and design of heat exchangers with fixed sheet tubes, straight and unconnected pipes are used, which are mechanically cleaned and there are no leaks in them.
Exchangers with U-shaped pipes
In order to increase the contact of the pipe fluid with the fluid inside the shell, U-shaped pipes are used in heat exchangers, which cannot be cleaned mechanically. The price of the U-shaped heat exchanger is at the Inexpensive level compared to other exchangers and it will be quite affordable to buy it.
Floating head heat exchanger
Floating head heat exchanger, which are in classes W, T, S and P, the end of the exchanger is not welded to the shell. At the front of the exchanger, a sheet of larger diameter pipe is welded to the shell. One of the most important features of this group of heat exchangers is their high resistance to thermal expansion and easy cleaning.
Washing shell and tube heat exchanger
The passage of various fluids through the exchangers gradually leaves a deposit on their body. For this purpose, it is necessary to regularly clean and wash them. Washing of shell and pipe heat exchanger is done by chemical and mechanical methods according to its type and how to install pipes.
Advantages of tube shell heat exchanger
Due to the many advantages of using heat exchangers in the industry, its use is increasing every day, which is one of the most important advantages of the tube heat exchanger can be mentioned as follows:
· High heat resistance (more than 260 degrees) and pressure higher than 30 bar
· Inexpensive and affordable price compared to other types of exchangers
· High diversity in the model and material used in the parts based on the environment used
· Easy chemical and mechanical cleaning
· Easy leak detection of pipes
Application of heat exchangers
Indirect heating of chemicals and fluids in various industries has caused the use of shell and tube exchangers to be highly regarded. In addition to its indirect heating, the advantages mentioned above are another reason why this group of exchangers has been used to such an extent. The main applications of shell and tube heat exchangers are:
· Oil and gas power plants and refineries
· Food and pharmaceutical factories
· Petrochemical Industries
· Metal smelting and manufacturing industries
· Fan coil preheater
· Cooling towers and boilers, radiators and etc.
Heat exchanger price
The very high variety of exchangers in the way of operation and the material of its different parts have caused the price of shell and tube heat exchangers to be very different. The main reason for this difference in the material of the body and pipes is the type of pipes inside the shell, the size and dimensions of the exchangers and other standards used in their manufacturing and design process. To inquire about the price of the heat exchanger, all you have to do is use the communication channels at the bottom of the page and contact the Seven Industrial Group, the manufacturer of the heat exchanger.
The best manufacturer of heat exchangers
Sensitivity and accuracy in the design and production of heat exchangers is very high and non-compliance with the standards of heat exchangers in it leads to a lot of damage. Therefore, it is necessary to choose the best options to buy a heat exchanger. Seven Industrial Group, using the experience and expertise of engineers and technicians in this field, has produced and offered various products in the group of heat exchangers. This manufacturer is a manufacturer of heat exchangers for various industries, factories and refineries, and according to the desired environment, offers suitable options for purchasing heat exchangers.