Steam generator

It is an equipment designed to transform feed water into saturated steam at a specific pressure. Along its path, the water coming from the boiler, which is already at a temperature close to saturation, absorbs the heat generated by combustion, allowing the phase change to occur progressively.

Once generated, the vapor returns to the reboiler, where a physical separation between the vapor and the liquid takes place. It may be the case of incorporating a shock evaporator, where the water coming from the reboiler first passes through the evaporator and then reaches the shock evaporator, where the phase change occurs, to be finally recirculated back to the reboiler.

How does a steam generator work?

An evaporator is placed after the flue gases leaving the boiler, taking advantage of its residual heat to transfer it to the saturated water leaving the boiler, converting it into a saturated water-saturated steam mixture. In this way, the evaporator reduces the amount of energy required to evaporate the saturated water, improving the thermal efficiency of the boiler and reducing fuel consumption.

Operation of a steam generator

Waste heat capture: The flue gases, which still contain a significant amount of thermal energy, pass through the evaporator.
Heat transfer: Inside the evaporator, the heat of the gases is transferred to the saturated water circulating in a closed circuit. This exchange takes place without mixing of the fluids.
Utilization of saturated steam: Saturated steam is directed to the reboiler, where it can be superheated or used in processes that require heat or steam, such as heating systems or production processes.
Reduced emissions and energy savings: By recovering and reusing heat that would otherwise be lost, fuel consumption and pollutant gas emissions are reduced.

It consists of:

Water/steam circuit: It consists of a set of tubes, which can be smooth or have fins. The system is complemented by two collectors located at the sides: one is in charge of receiving and distributing the inlet water, and the other collects the water/steam mixture generated.
Gas circuit: Circulates outside the tubes and is located perpendicular to the path of the thermal fluid.

What types of steam generators are there?

Aitesa designs the following types of evaporators:

Natural circulation evaporator

The movement of the water inside the equipment is produced by the difference in density between the liquid at the inlet and outlet. Generally, in this type of evaporators the tubes are placed in vertical position and with a single pass, although configurations with the tubes in horizontal arrangement can also be adopted.

Forced circulation evaporator

The water flow in the system is achieved by means of pumps, which allow overcoming the head loss generated in the equipment. In this case, the usual arrangement is with pipes in horizontal position, being able to have one or several fluid paths.

Shock evaporator

Unlike the previous classifications, which are based on the water circulation mode, these units are distinguished by withstanding gas inlet temperatures of up to 950 °C. Their main function is to reduce the temperature of the gases before they pass to the rest of the boiler modules, thanks to their ability to absorb a large amount of heat from the flue gas by using the latent heat generated during the evaporation of the water flowing inside the tubes.

Not sure which one you need? Our team of experts can analyze your process and recommend the best solution.

At AITESA we are experts in the design of steam generators.

Key benefits for your industry

Energy savings and thermal efficiency

The use of evaporators allows heat recovery from the exhaust gases, which would otherwise be lost, to generate saturated steam. This reduces the amount of fuel required to reach the desired operating temperatures, improving the thermal efficiency of the system.

Controlled steam generation

Thanks to the evaporators, a constant and regulated supply of steam is achieved, which, together with other systems such as the boiler, provides precise steam temperatures and pressures, essential for industrial processes.

Reduced operating costs

By improving energy efficiency, evaporators contribute to a significant reduction in operating costs. The reduction in fuel consumption not only implies direct savings in energy costs, but by applying preventive maintenance methods, the wear and tear of the main equipment can also be minimized, prolonging its useful life and reducing maintenance costs.

Reduction of pollutant emissions

The energy efficiency achieved by evaporators also has a positive impact on the environment. By reducing the consumption of fossil fuels, emissions of greenhouse gases and other pollutants are reduced. This contributes to a company’s lower carbon footprint and improves its environmental profile, which is increasingly valued in the marketplace and can facilitate compliance with environmental regulations.

Adaptation to customer needs.

We adapt the evaporators to different environments and needs. They can be configured according to the specific requirements of each process, such as pressure, temperature or the amount of steam needed. They are also compatible with existing equipment, which facilitates their integration without the need for major changes to the existing system.

Vaporizador en operacion en una planta agroalimentaria de Barcelona

Vaporizer in operation at an agri-food plant in Barcelona, Spain.

Levantamiento de un vaporizador para su montaje en planta termosolar

Lifting of a vaporizer for assembly in a solar thermal plant.

Industrial sectors where steam generators are used

Petrochemical and refinery industries

Industrial evaporators offer key advantages in complex processes such as catalytic cracking, distillation or hydrogen production, where waste heat utilization is essential. They can be made of materials resistant to corrosive gases, making them particularly suitable for demanding conditions such as those found in the petrochemical industry. By recovering heat that would otherwise be lost, they contribute significantly to reducing energy consumption in refining and fuel production processes, thus improving overall plant efficiency.

Cement and glass industries

In industries such as cement and glass, evaporators allow the waste heat generated in clinker kilns and glass furnaces to be used to produce saturated steam. This steam can be used in thermal processes or for power generation, which significantly improves the energy efficiency of the fuel used. As a result, primary energy consumption and polluting emissions are reduced, contributing to both economic savings and compliance with environmental regulations.

Food industry

In the food industry, steamers play an essential role in many processes, such as pasteurization, cooking, sterilization or CIP cleaning. This equipment allows saturated steam to be generated in a controlled and efficient manner, taking advantage of available heat sources. The use of steamers optimizes energy consumption, since it adapts to the real demand of the process, avoiding losses and improving the overall performance of the plant. In addition, by guaranteeing a constant and safe supply of steam, the hygienic and sanitary quality of the products is ensured, which is essential in this sector. As a result, it not only improves operational efficiency, but also contributes to compliance with stringent food safety and sustainability regulations.

Paper industry

In the paper industry, evaporators are essential for processes such as pulp drying. Thanks to evaporators, energy consumption is optimized in one of the most intensive stages of the process, drying, resulting in a significant reduction in energy costs. In addition, by providing a stable, quality steam, it improves the yield and uniformity of the final product, key factors in paper production. In this way, the evaporators not only improve overall plant efficiency, but also contribute to meeting environmental and sustainability objectives in an increasingly regulated industry.

Do you need a customized solution for your industry? Contact us and we will design the ideal equipment for your process.

Key factors in choosing the right evaporator

Sizing and capacity

Heat available in gases.
Space limitations
Adaptability to existing installations

Process conditions

Flow rate
Temperature
Pressure
Fouling factor
Fluid velocity

Modular design and adaptability to existing installations

Integration without modifying the plant infrastructure.
Configuration to fit the available space.

Compliance with international regulations

ASME, API 661, ISO 9001, EN 12952 certifications for maximum safety and quality.
Design adapted to specific requirements of the petrochemical, energy and manufacturing industries.

Compliance with customer specifications

Adaptation to specific customer requirements

Transporte de un vaporizador mas calderin a una planta quimica

Transportation of a vaporizer plus boiler to a chemical plant

At AITESA we study your case to offer you the best steam generator.

Vaporizador fabricado listo para el transporte

Vaporizer manufactured ready for transport

Why choose an AITESA evaporator?

More than 5000 projects in strategic sectors

40 years of experience designing evaporators.
Adaptation to demanding environments such as refineries, petrochemical and industrial plants, where every degree of efficiency optimizes profitability.

Maximum efficiency and minimum emissions

Proven and optimized designs: our experience allows us to guarantee robust and safe solutions for every industry.
Reduced environmental impact with minimum heat loss and maximum thermal efficiency.
Reduced operating costs with advanced technology that maximizes thermal efficiency and minimizes energy waste.

Comprehensive technical support and maintenance