Desuperheaters


Transvac direct contact Desuperheaters reduce the temperature of superheated steam to produce steam temperatures approaching saturation temperature (typically to within 3°C of the saturation temperature). To cool the superheated steam a medium, usually water, is entrained and flashed into vapour by absorbing heat from the steam.


Transvac Desuperheaters

Typical applications:

  • • To reduce the temperature of steam discharged from turbine by-pass systems on power plants for heat exchangers, dump stations etc.
  • • To improve heat transfer of indirect contact heat exchangers - shell & tube , plate type, reactor heating jackets
  • • To reduce the temperature of steam on direct contact applications - food cooking kettles, in-line steam heaters, tobacco drying plant and paper mills.

Advantages

  • • Low cost, simple, robust design
  • • No moving parts to wear
  • • Minimal steam pressure drop
  • • Flexible design options

Construction

Transvac Desuperheaters are available built to our own proprietary codes of practice or to ASME VIII div 1, PD5500, Stoomwezen and other recognised design codes. Units can be CE marked on request. Connections are sized to suit the process conditions. Standard materials of construction include carbon steel, stainless steel, chrome molybdenum steel etc, however we can also manufacture in other metals or alloys requested.

Which Desuperheater is right for my application?


Transvac Desuperheaters
Please note this is a general guide and does not represent every option available. Please contact us if you have any queries.

Spray type Desuperheaters

A simple type of in-line Desuperheater with cooling water injected into the centre of the unit via an atomizing nozzle sprayed in the direction of the steam flow. Transvac Spray Type Desuperheaters are available in two options:

1. Simple Spray Type Nozzle Desuperheater (SND)

The assembly is designed for mounting on a suitable flanged branch on the steam pipework. A thermal sleeve installed down stream of the unit is recommended.

Transvac Spray Type Nozzle Desuperheater

2. Complete Spray Type Desuperheater (STD)

A complete Desuperheater ready for installation including spray nozzle, nozzle housing, thermal sleeve and flanged shell.

Transvac Spray Type Nozzle Desuperheater

Applications

• Relatively constant load handling duties
• Turndowns up to 3:1 depending upon conditions



Venturi Type Desuperheaters (VTD)

The venturi principle is used to create regions of high velocity and turbulence which produces intimate contact between the steam and cooling water.

Transvac Venturi Type Desuperheater

Applications

• Suitable for most general plant applications, except where high turndowns on cooling water are required



Steam Atomizing Type Desuperheaters (SAD)

A high pressure auxiliary steam supply is used to atomize the incoming water within the diffuser of the unit.

The auxiliary steam pressure needs to be at least 1.5 times the Desuperheater inlet pressure with a minimum pressure of 3 bar g.

Transvac Steam Atomizing Type Desuperheater

Applications

• Variable load handling duties up to 20:1



Desuperheating & Pressure Reducing Stations

Transvac can provide complete Desuperheating & pressure reducing stations, including control valves, temperature sensors, pressure transmitters, instrumentation and pipework, all mounted on a support skid.

Transvac Steam Atomizing Type Desuperheater