Purpose of boiler steam superheaters: types, schemes

For all homeowners, a primary concern is efficiently and effectively heating their homes. Finding ways to optimize heating systems has become more crucial as energy costs rise and environmental impacts become more widely recognized. The boiler, which acts as the system’s central component, is essential to many heating systems. However, the steam superheater—a lesser-known hero—lies within this boiler.

So what is a steam superheater exactly, and why is it so important? To put it simply, a superheater is a boiler component that raises the temperature of steam above its saturation point to create superheated steam. Although this may sound technical, the goal is actually very simple: to maximize the boiler’s performance and energy efficiency.

Steam superheaters come in a variety of forms, each with a unique set of goals. The objective of all superheaters, whether they are convection or radiant, is the same: to improve the boiler’s steam output. These superheaters use a variety of methods to accomplish this, including indirect heating from outside sources or direct heating from the combustion gases.

Optimizing the performance of steam superheaters in heating systems requires an understanding of the various schemes that they use. Every scheme, whether it’s a multi-stage configuration or a single-stage superheater, has pros and cons. The choice of superheater scheme is influenced by various factors, including operating temperatures, desired steam parameters, and space constraints.

Boiler steam superheaters serve purposes beyond increasing efficiency, in the end. These appliances contribute to smoother operation, lower maintenance needs, and longer equipment lifespan by generating high-quality superheated steam. Examining the complexities of steam superheaters reveals another level of innovation that is propelling the search for the best possible home comfort and energy efficiency as we dig deeper into the world of insulation and heating.

Purpose of the superheater

A steam superheater is a device that raises a boiler’s saturated steam temperature. Because of the way it is made, steam can be heated above the saturation point using the same indicator.

Because of the impact of high temperatures on its surfaces, the device operates under high loads. The steam superheater collector reaches its maximum temperature. The boiler equipment’s efficiency is greatly increased by superheating saturated steam.

Saturated steam is produced while the boiler apparatus is in operation. A portion of the steam mass condenses during motion. In order to prevent significant volumes of water from changing from a gaseous to a liquid state, the steam is heated to a high temperature.

Steam superheater design

The appliance is found in the boiler’s furnace or gas duct. The steam boiler superheater is constructed from many small-diameter pipe coils made of metal. Manifolds link the ends of the coils to one another. Steam passes through connecting manifolds and enters the coils.

Installed in the gas duct, the device’s outer surfaces are washed over by combustion products. Carbon steel products with a round or rectangular cross section are called collectors.

There are two kinds of them:

  1. Welded.
  2. All-metal.

Tight connections between the coils and collectors are necessary for the superheater to function. This will prevent any vapor from seeping into the gas duct. To achieve a tight connection, the coil ends are rolled inside the collector. Specialized hatches are made on the wall opposite it for this purpose. A series of rows of steel coils can be used in the superheater design, depending on the boiler capacity.

Fixing the pipes necessitates drilling numerous holes in the manifold, which compromises its strength properties. Additional collectors may be installed in such circumstances. The coils can be positioned horizontally when using boiler equipment that runs on fuel that produces very little ash.

In other cases, the tubes are installed vertically to allow steam to pass through. The horizontal location of the superheater coil facilitates the procedure of water drainage during boiler shutdown.
Depending on the type of device, the corridors between the tubes may be subject to slag clogging. It is difficult to clean the openings for flue gas movement. For this reason, structures forming narrow passageways are placed at greater distances from each other.
The device is mounted using specialized hangers. Their fixing is carried out in such a way as to ensure free movement of pipes for steam movement during their thermal expansion. The hangers are made of metal that is resistant to high temperatures.

Operating principle

The steam is heated using combustion products in a steam superheater. Exhaust gases flowing between the tubes clean the coils’ exteriors while they are in operation. Within the coil, steam flows.

The temperature of the medium inside the pipes can vary based on how the steam moves in relation to the movement of combustion products. As a result, steam superheaters with countercurrent steam medium direction have the highest temperature index.

The superheater can be placed inside the furnace or right next to the superheated steam accumulation chamber, depending on the kind of device. In order to ensure that the steam movement velocity remains constant despite pipe bends, the product is installed at an angle towards the outlet collector. Install radiation-type devices on the furnace’s walls or ceiling to raise the coefficient of heat exchange. A ceiling steam superheater can enhance heat exchange by up to 40%.

Convection and radiation devices are installed together in certain boilers. The steam superheater’s efforts have made the following possible:

  • to increase the efficiency of the boiler equipment;
  • rationally use the heat of exhaust gases;
  • transmit the mass of steam over a long distance.

In understanding the vital role of boiler steam superheaters, it"s crucial to recognize their primary purpose: enhancing the efficiency and performance of boiler systems. These superheaters serve to elevate the temperature of steam produced by boilers to levels beyond saturation point, ensuring a higher energy content and more effective utilization of heat. They come in various types and schemes, each tailored to specific boiler designs and operational requirements. By superheating steam, these components contribute to improved energy production, reduced fuel consumption, and enhanced overall system reliability. From radiant to convection superheaters, the diversity of configurations allows for optimization in diverse industrial and residential heating applications. Understanding the significance of boiler steam superheaters unveils their pivotal role in achieving energy efficiency and maximizing the effectiveness of heating systems.

Classification of steam superheaters

The devices are classified as radiative, convective, or screen-mixed types based on their design features. For a single boiler, it is occasionally possible to combine various device types.


The apparatus operates with a high heat load. This is because of where the radiation superheater is located. The product is fixed to the furnace’s vertical walls or ceiling.

The radiation that is created when the fuel burns transfers a significant amount of heat to the pipe’s exterior surfaces. In radiation-type devices, the temperature of steam heating is higher than the same indicator in convective designs. Both kinds of devices are occasionally installed simultaneously.

Partial heating is accomplished by a radiant superheater and finished in a convective type device.


Convective steam superheater installation is done in the boiler’s gas duct. The combustion products transfer heat to the pipes’ exterior surfaces. Steel pipes are used as the raw material to make coils. The outer diameter and wall thickness of the pipes may vary based on the pressure for which the coil is intended.

A boiler with a large capacity can have multiple rows of pipes installed. Convective type devices can be classified into the following categories based on the direction of the steam with respect to the exhaust gases:

  • direct-flow;
  • countercurrent;
  • mixed.


In this kind of convective superheater, the movement of steam is counteracted by the movement of exhaust gases. When utilized in a gas environment with a temperature below 850 degrees Celsius, the design exhibits high efficiency.

Depending on the properties of the metal used to create the coils, this may be decreased. The pipes at the start of the combustion product movement and the end of the steam are the most prone to burnout. This is because both media have reached their highest temperature.

A brief film from the channel Tverskaya Generatsiya


Steam flows in the same direction as exhaust gases in designs with a direct flow. Since cooled gases heat the maximum heated steam at the coil’s end, this lowers the temperature load on the pipes’ metal.


The best conditions are found in convective mixed type steam superheaters, which can produce a large amount of high temperature steam using steel tubes.

The exhaust gas flow and the medium flow within the tubes occur simultaneously in opposite directions.


A screen steam superheater is a vertically oriented structure composed of numerous steel tubes.

The combustion products flow into the opening formed by their formation of flat panels. Both convective and radiative heat transfer occur to the screen superheater’s surfaces. As the combustion products travel along the belts, heat is transferred to their exterior surfaces. The spacing between the screen superheater’s strips is between 55 and 70 centimeters to prevent slag from clogging the passageways between them.

The individual tubes are tied together horizontally with specialized inserts to keep them contained within the belt. These stop the elements in the middle from escaping past the belt and are fastened to the screen’s outermost tubes. By using radiation and glowing combustion products, the screen superheater’s medium is heated inside its tubes. Certain screens are composed of pipes with protrusions on their side surfaces.

These kinds of structures are less vulnerable to external contamination. The tubes are unable to exit their row due to the side projections.

Superheaters made of boiler steam are essential for improving home heating systems’ effectiveness and efficiency. Superheaters make sure that the heat produced by boilers is used as efficiently as possible by raising the temperature of the steam they produce, which improves home heating.

There are numerous kinds of superheaters that are available, and each has special benefits and uses. Depending on their unique heating needs and tastes, homeowners can select from a variety of options, including convective and radiant superheaters. When choosing the best superheater for their heating system, homeowners can make more informed choices if they are aware of the distinctions between these types.

Optimizing heating performance also heavily depends on the superheater scheme—the configuration of superheaters within the boiler system. Every superheater scheme, whether single-, two-, or three-stage, has unique advantages in terms of overall system reliability and heat transfer efficiency.

Purchasing a high-quality boiler steam superheater and choosing the appropriate plan can save a lot of energy and raise home comfort levels. A more economical and ecologically friendly heating solution for homes can be had by homeowners by optimizing the process of heat transfer and reducing heat loss.

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Sergey Ivanov

I like to help people create comfort and comfort in their homes. I share my experience and knowledge in articles so that you can make the right choice of a heating and insulation system for your home.

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