Superheater


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Related to Superheater: steam superheater, Reheater

superheater

[¦sü·pər′hēd·ər]
(mechanical engineering)
A component of a steam-generating unit in which steam, after it has left the boiler drum, is heated above its saturation temperature.

Superheater

 

a component of a boiler unit that superheats steam, that is, heats steam above its saturation temperature. A superheater consists of parallel-mounted steel tubes, with internal diameters of 20 to 60 mm, connected directly to a boiler drum or to input, output, and intermediate headers. Depending on the direction in which the steam moves relative to the flue gases, superheaters are said to have parallel flow (uniflow), counterflow, or mixed flow. They are classified as radiant, screen (semiradiant), or convection according to the location of the superheater in the boiler and the type of heat exchange that results.

Radiant superheaters are placed on the crown or walls of a furnace chamber, often between the tubes of waterwalls. The superheaters and waterwalls take up heat radiated by the burning fuel. Screen superheaters, which are separate flat screens of tubes connected in parallel, are mounted in the outlet from the furnace ahead of the convective part of the boiler; heat is transferred by both radiation and convection. Convection superheaters are placed in the flue of a boiler unit, usually after the screens or beyond the furnace; they consist of multirow banks of coils.

Superheaters composed entirely of convection stages are usually installed in average- or low-pressure boiler units having superheated steam no hotter than 510°C. High-pressure boiler units with considerable steam superheating use composite superheaters, which include convection, screen, and sometimes radiant sections.

The boiler units of steam electric power plants always have superheaters, because increased steam temperature means higher thermal efficiency for the plant. When steam pressure is 14 meganewtons per sq m (140 kilograms-force per sq cm) and higher, secondary (intermediate) superheaters are usually used along with basic (primary) superheaters in order to superheat steam that has been partly used up in a turbine.

G. E. KHOIODOVSKH

superheater

A heat exchanger for heating steam above 212°F (100°C) at atmospheric pressure.
References in periodicals archive ?
[ClickPress, Tue Aug 28 2018] The report "Steam Boiler System Market by Component (Boiler, Economizer, Superheater, Air Preheater, and Feed Pump), Type (Watertube Boiler, and Fire Tube Boiler), Fuel (Coal, Gas, Biomass, Oil, and Electric), End-user, and Region- Global Forecast to 2023", The steam boiler system market is expected to grow from an estimated USD 17.66 billion in 2018 to USD 21.63 billion by 2023, at a CAGR of 4.13%.
The aim of the injection of technical water after the steam superheater of the boiler activates the free calcium oxide in the OS fly ash and the increase of the efficiency of the flue gas desulphurisation by it [8].
Superheater and reheater tubes were made of a low-alloy steel, ASTM A213 T22 and A213 T12, respectively, with a chemical composition presented in Table 1 [5].
The steam will then be sent to the superheater installed atop the small tower, where, by heliostat-based sunlight collection, it will be further heated to 550degC.
Aurora was added to the coal and slag observations at the superheater were made twice daily then rated from 0 (no deposition) to 4 (severe).
The point to be specifically taken care of in the use of T91 material is its design limitations and it must be acknowledged during design stage: l) cost of fabrication is higher, due to strict quality control and subsequent stress relieving and heat treatment; 2) procurement of quality material from reputable steel mills; 3) control of design pressure drop through the secondary superheater with the thinner-walled T91 tubes; 4) avoidance of dissimilar metal welds and very careful weld design; and 5) concerns relating to effective quality control.
The melting process begins while the furnace is being filled, so the first iron pours out of the siphon into the electrically heated superheater in 15 minutes.
Depending on the severity of tube corrosion, the condition may necessitate more frequent replacement of superheater pendant tube sections or the use of costly, higher alloyed materials, either to shield metal surfaces or serve as replacement tube material.
Much progress has been made toward minimizing carryover deposit problems in the superheater region, but fouling and blockage of boiler bank gas passages by fine, sub-micron size fume or dust particles has persisted as a problem.
These properties will especially suit the technical service requirements of the superheater and reheater sections of advanced coal-fired boilers in today's electric power plants.
Metalborne waveguides can detect sounds of leaks from a superheater, economizer or other source inside the boiler.
gas-oil steam boiler with natural circulation gas-tight with a water economizer and a superheater with a capacity of 50 t / h with steam output parameters: p = 1.