Sunday, 29 March 2015

Shell and tube heat exchanger

Shell and tube heat exchanger

A shell and tube heat exchanger is a class of heat exchanger designs. It is the most common type of heat exchanger in oil refineries and other large chemical processes, and is suited for higher-pressure applications. As its name implies, this type of heat exchanger consists of a shell (a large pressure vessel) with a bundle of tubes inside it. One fluid runs through the tubes, and another fluid flows over the tubes (through the shell) to transfer heat between the two fluids. The set of tubes is called a tube bundle, and may be composed of several types of tubes: plain, longitudinally finned, etc.
Heat is transferred from one fluid to the other through the tube walls, either from tube side to shell side or vice versa. The fluids can be either liquids or gases on either the shell or the tube side. In order to transfer heat efficiently, a large heat transfer area should be used, leading to the use of many tubes. In this way, waste heat can be put to use. This is an efficient way to conserve energy.
Heat exchangers with only one phase (liquid or gas) on each side can be called one-phase or single-phase heat exchangers. Two-phase heat exchangers can be used to heat a liquid to boil it into a gas (vapor), sometimes called boilers, or cool a vapor to condense it into a liquid (called condensers), with the phase change usually occurring on the shell side. Boilers in steam engine locomotives are typically large, usually cylindrically-shaped shell-and-tube heat exchangers. In large power plants with steam-driven turbines, shell-and-tube surface condensers are used to condense the exhaust steam exiting the turbine into condensate water which is recycled back to be turned into steam in the steam generator.

Different types of shell and tube heat exchangers and their applications

The simple design of a shell and tube heat exchanger makes it an ideal cooling solution for a wide variety of applications. One of the most common applications is the cooling of hydraulic fluid and oil in engines, transmissions and hydraulic power packs. With the right choice of materials they can also be used to cool or heat other mediums, such as swimming pool water or charge air. One of the big advantages of using a shell and tube heat exchanger is that they are often easy to service, particularly with models where a floating tube bundle (where the tube plates are not welded to the outer shell) is available.

TDW

Design feature:

  • High thermal efficiency utilising newly developed spiral oil flow baffles
  • Standardised in 21 sizes and various types
  • Removable U-tube bundle with finned tubes made from tinned Cu and other materials
  • 4-pass coolant flow
  • Low operating costs due to low water consumption

-Application:

Especially suited for cooling of lube oil and hydraulic oil in engines, transmission. Also used in the plastic machinery industry.

BCF/ CCF

Design feature:

  • Standardised and prefabricated in 212 sizes and various types
  • Non-removable tube bundle available in a range of materials
  • Removable cast iron bonnets available for 1, 2 or 4-pass design
  • quick calculation - quick delivery

-Optional:

  • U-Version with U-tubes
  • P-Version with removable bundle

-Application:

Cooling, heating and condensing of different media either by fluids or steam. Typically used in process engineering as well as in mechanical and plant engineering. Decades of proven reliability in cooling of lube oil and hydraulic oil, in the tool, plastic and compressor industry. 

SSCF

Design feature:

  • The standardised and pre-engineered counterpart of the BCF line, but made of stainless steel 1.4571(V4A).

-Application:

Ideally suited for the chemical, refining, pharmaceutical, and process industries where aggressive fluids are to be heated or cooled.

CCFA

Design feature:

  • Non-removable tube bundle, 1-pass design
  • Very high compressive strength
  • Best price performance ratio

-Application:

Especially suited to cool air and gas, especially very high pressures. To be used as intercooler or after cooler.

Univex-compact series

Design feature:

  • High specific heat dissipation due to the compact tube bundle and 4-pass cooling water flow
  • Removable tube bundle with tubes made of CuNi10Fe, bonnets bronze, seawater resistant
  • Regular supply of mounting positions
  • Short delivery times, attractive price performance ratio

-Application:

Cooling of: hydraulic oils and lube oils, converter oils, cutting oils, cooling oils, hydraulic liquids, water/glycol. Low-cost coolants that can be used are: service water and seawater.

References

  1. www.wikipedia.org

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