Desuperheating, sometimes called attemperation or steam conditioning, is the reduction of gas temperature. It's most common application is the reduction of temperature in a steam line through the direct contact and evaporation of water. Our desuperheaters use uniquely effective methods to inject the water and maximize the surface contact area between the steam and water to increase the rate of water evaporation. Most of our desuperheaters inject water through several small holes into the path of the high velocity steam where the water is atomized Into small water droplets and quickly evaporated into the steam. Thermal pipe liners are not normally required.
Desuperheaters are used in power boiler heat recovery systems, for superheater Interstage temperature control, paper dryer drum temperature control, steam kettle or cooker temperature control, and aircraft catapult machines.
Most desuperheaters can be installed horizontally or vertically. Desuperheaters are often supplied with steam and water control valves and controllers to provide an automatically controlled system. The controllers can be either pneumatic or electronic.
The construction material is normally carbon steel for the outer pipe or wall with 316 stainless steel for the wear parts. Other weldable machinable metals may also be used. In some applications, fiberglass, Teflon, or other plastic may be a suitable fabrication material.Operation:
Desuperheaters reduce the temperature of superheated steam to produce lower temperatures (normally 10° F above saturation, although Type 6910 is capable of producing saturated steam). The majority of our units (except Types 6905 and 6910) require water at line pressure. Water is syphoned into the water box/combining tube assembly, where it is heated, and then mixed with a percentage of steam through the throat region and introduced into the steam line as a finely atomized mist. Water entrainment, shearing and mixture, all within S & K internal construction, produces extremely small water particles and alleviates requirements of thermal liners and impingement shields. For Type 6905, where water is injected at high pressure and internal construction consists of a water nozzle, we supply or recommend thermal liners.Advantages:
Desuperheaters are manufactured from a variety of metals. Standard construction is carbon steel below 800° F, chrome molybdenum steel above 800° F(both with stainless steel Type 304 internals); however, we can manufacture in any metal or alloy requested.
|Select a Desuperheater:|
|Type 6950 Venturi Desuperheater|
|A venturi-type, steam atomizing unit with no separate or high pressure steam supply required. Suitable for use under a wide range of conditions, including steady or variable flows. Inlet water pressure need only equal steam pressure. Small pressure drop across unit. Used with or without controls.|
|Type 6940 Venturi Desuperheater|
|Also a venturi-type similar to the Type 6950, but with an integral steam inlet flange connection. Performance is similar to the Type 6950|
|Type 6940M Venturi Desuperheater|
|"Mini" venturi in sizes 1/2" to 1-1/2". Used in extremely low flow applications such as found in heating and air conditioning services. Available with flanges, threaded or socket weld connections.|
|Type 6952 Attemperator Desuperheater|
|A modification of Type 6950 in which the tail piece is omitted and the atomized water discharges directly into the pipeline. Suitable for use where lower pressure drop is required and little flow variation is encountered.|
|Type 6953 Attemperator Desuperheater|
|A version of Type 6952 with the same operating characteristics. Flanged or buttwelded ends.|
|Type 6905 Special Application Desuperheater|
|Uses one or more spray nozzles mounted on the periphery for injection of water into the steamline. A thermal shield downstream of unit is recommended.|
|Type 6910 Special Application Desuperheater|
|Type 6910 Desuperheater-Surface absorption type wherein steam contacts wetted reaction rings. Highest pressure drop of units shown. Unit can be used with controls and flow can vary almost infinitely with no downsteam piping requirements. Can achieve saturation.|
|Type 6970 Ejector Atomizing Desuperheater|
|A steam ejector, atomizing unit with water recycle arrangement. For applications where combined reducing-desuperheating station is required and flows vary widely. Steam flow range can be as high as 50 to 1 and greater, depending on operating conditions. Minimum atomizing steam pressure required is about 1.4 times inlet steam pressure, with low pressure drop across unit in most cases.|
|Type 6972 Ejector Atomizing Desuperheater|
|Same as Type 6970, but without the recycling system. Gives reduced flow variation and costs less to install.|
|Type 6985 Annular Venturi Desuperheater|
|Lower cost venturi-type capable of high turndown ratios. Suitable for use under wide range of conditions, including steady and variable flows. Low pressure drop. Inlet water pressure need only equal steam pressure.|