Shell and tube heat exchangers are used for the indirect heating or cooling of fluids. As the name implies, a shell and tube heat exchanger consists of two main parts, an outer “shell side” and an inner “tube side,” which sits inside the shell. One fluid flows in the annulus between the inside wall of the shell and the outside wall of the tubes, while the other fluid flows inside the tubes. Heat Transfer within a Shell and Tube Heat Exchanger occurs by heat passing from the cooler fluid to the hotter fluid, through the wall of the tube.
Shell and tube heat exchangers are often described as the "workhorse” of the industrial process industry. The shell and tube heat exchanger is an immensely versatile unit, able to handle a wide range of process applications and conditions. Whether you are looking to cool, heat, vaporise or condense, the shell and tube heat exchanger can meet your needs.
Reasons and conditions under which shell and tube heat exchangers are selected include:
TEMA is a Standard published by the Tubular Exchanger Manufacturers Association, Inc. (TEMA) for the mechanical design of shell and tube heat exchangers.
The TEMA Standard for shell and tube heat exchangers meet the requirements of most users. Your requirements may exceed the TEMA Standard, but will very rarely be less than. For industrial applications, we would recommend that the TEMA standard be your minimum level of acceptance.
The TEMA Standard is based around the ASME Design Code but is not itself a Design Code. While it is based around ASME, it may be also be used in conjunction with other design codes such as PD5500 or EN13445. Other Standards also exist such as API 660 / ISO 16812 - Petroleum, petrochemical and natural gas industries - Shell-and-tube heat exchangers.
Many users only experience TEMA for the purpose of Nomenclature and describing their requirements. However, TEMA goes much deeper covering areas such as Fabrication Tolerances, Performance Information, Installation, Operation, and Maintenance, Mechanical Standards, Flow Induced Vibration etc.
While almost every shell and tube heat exchanger is different in its design, they do generally have similar geometry characteristics, that allow them to be described through the TEMA three letter system. The table below shows how this lettering system works.
Selection of the configuration can depend on a wide range of factors such as whether the bundle needs to be removed for cleaning, whether the liquids are hazardous or what the pressures and temperatures the unit will see, to name but a few.
Our experienced Thermal Design Engineers will be able to propose an arrangement to meet the your individual requirements.
Using the above nomenclature, here are some examples...
The more information that a client can supply, the closer the design can meet the process requirements. The minimum information required, however, is as follows:
Whether it be NACE spec materials for the Oil Industry or weld overlayed / explosively bonded tubesheets, we manufacture heat exchangers in most combinations of materials.
With over 49 years of experience in the design and manufacture of shell and tube heat exchangers, Graham Hart (Process Technology) Limited is well known for the production of their TEMA type shell and tube heat exchangers.
Units are exported world-wide and range from 100mm shell diameter up to 50 tonnes, with mechanical design to PD5500, ASME VIII Div I & Div II, BS EN 13445 and Stoomwezen.
But why should you choose Graham Hart (Process Technology) Ltd as your your partner?