Waste heat recovery boiler

In many industrial processes, a great deal of energy is lost through hot flue gases or exhaust gases. With a waste heat recovery boiler, you can recover this residual heat and convert it into usable process steam.

This way, energy that would otherwise go to waste can be put to good use within the production process. The result: lower fuel consumption, higher energy efficiency and reduced CO₂ emissions.

The specialists at Callens Group analyze your energy streams and design waste heat recovery boilers that get maximum value out of the available residual heat.

Explore your options

When is a waste heat recovery boiler worthwhile?

Not all energy has to be generated from scratch. In many production environments, there is plenty of heat available in the flue gases of gas turbines, engines, CHP units, furnaces, drying processes or other industrial installations.

A waste heat recovery boiler recovers this heat and converts it into process steam without any additional fuel consumption. That’s why this technology is often one of the most cost-effective forms of energy recovery.

5 reasons to choose a waste heat recovery boiler

Your installation produces hot flue gases or exhaust gases.
You have a CHP unit or gas turbine.
You want to increase the efficiency of your power plant.
You want to consume less natural gas for steam production.
You want to lower the CO₂ emissions of your site.

Output	up to 40 MW
Capacity	25 to 55,000 kg/h steam
Design pressure	0.5 to 30 barg
Efficiency	up to 95 %

Technical specifications of a waste heat recovery boiler

The design of a waste heat recovery boiler is determined first and foremost by the properties of the available exhaust gases. Factors such as temperature, flow rate, composition and operating hours determine how much heat you can recover and how much steam that heat can generate.

In addition, we look at the desired steam pressure, the steam consumption and the integration within the existing energy infrastructure.

Our engineers analyze these parameters and design an installation that makes optimal use of the available residual heat to supply you with an efficient heat source tailored to the operational needs of your production environment perfectly.

advantages

Advantages of a waste heat recovery boiler

Heat recovery is often among the most efficient ways to lower the energy consumption of an industrial site. A waste heat recovery boiler taps into energy that is already present within the process and converts it into usable process steam.

Less fuel consumption

Part of the required steam is produced without any additional fuel.

Lower energy costs

By recovering existing heat, the need for externally generated energy drops.

Higher energy efficiency

More energy remains available within the production process.

Lower CO₂ emissions

Because fewer primary fuels are needed, the related emissions drop as well.

Fast payback period

Waste heat recovery boilers are often one of the most cost-effective energy recovery projects within industrial environments.

Maximum valorization of residual heat

Heat that would otherwise be lost gains a useful application once again.

How do you integrate a waste heat recovery boiler into your existing infrastructure?

We connect a waste heat recovery boiler directly to the installation that releases the residual heat. That can be a CHP unit, gas turbine, furnace, drying installation or other component.

The steam produced is then integrated into the site’s existing steam network, taking account of the steam pressure, steam capacity, operating hours and the interaction with existing steam boilers.

Discuss your integration

Maintenance of your waste heat recovery boiler and 24/7 service

The Callens Group’s maintenance and service team makes sure your installation keeps performing at its best, even after commissioning. With an in-house team of more than 120 service and maintenance technicians, we schedule preventive maintenance in line with the legal and technical requirements of your installation.

You can also count on fast support whenever an unexpected breakdown occurs. Thanks to our 24/7 on-call service, an extensive range of spare parts and the expertise of our service technicians, we carry out interventions quickly and effectively.

Even the best maintained installation can malfunction or shut down unexpectedly. That’s why the Callens Group offers various service packages, tailored to the response time and support you need. So even in unforeseen situations, you can count on our expertise.

More information about our service contracts

Ensure maximum heat transfer with the (S)APCS boiler cleaning system

In waste heat recovery boilers, dust, fly ash and other deposits can build up on the heat exchange surface. When the flue gases cool down, these particles can settle on the inside of the boiler’s smoke tubes. As a result, heat transfer decreases, energy consumption increases and the risk of unplanned shutdowns grows.

With the Callens Group’s (S)APCS boiler cleaning system ((Semi-)Automatic Pipe Cleaning System), the boiler’s smoke tubes are cleaned automatically during the installation’s normal operation. This keeps thermal efficiency up to standard without frequent production stops for cleaning being required. That way, you get maximum value out of the available residual heat, reduce maintenance needs and ensure reliable operation of your energy installation.

Explore the possibilities

Maximizing energy efficiency doesn’t start with choosing a technology, but with mapping out your environment and goals.

Do you have a project inquiry?

Tell us about your challenges. We turn them into
practical advice.

FAQ

Questions? We have the answers.

Pour un client actif dans le secteurs des huiles et des graisses, Callens Group a réalisé une nouvelle centrale de production de vapeur équipée d’une chaudière à vapeur de secours au gaz et d’une installation de générateur de vapeur à récupération de chaleur couplé à une turbine à gaz. L’installation existante était aux prises avec de nombreuses pannes qui mettaient sous pression la stabilité du réseau de vapeur et les températures de procédé. Une chaudière de secours de 23 tonnes de vapeur par heure a permis de rétablir la continuité du procédé de production. Le projet a débouché sur une production de vapeur plus efficace et plus fiable, avec une capacité de 23 t/h au gaz naturel, un timbre de 18 barg et une pression de service de 15 barg. Decouvrez le projet ici.

A conventional steam boiler produces steam by burning fuel. A waste heat recovery boiler, on the other hand, uses the heat that is already present in flue gases or process gases to generate steam. This makes it possible to produce process steam with no, or limited, additional fuel consumption.

That depends on factors such as the temperature, flow rate and composition of the exhaust gases. In many industrial processes, the exhaust gas stream still contains enough heat to cover a significant portion of the steam demand. An analysis of the energy streams determines how much heat can effectively be recovered.

Waste heat recovery boilers are often used downstream of CHP units, gas turbines, industrial furnaces, drying installations, thermal oxidizers and other processes that release hot flue gases. Each situation is evaluated individually based on the available heat content.

Yes. When the temperature and flow rate of the exhaust gases are high enough, the waste heat recovery boiler can run entirely on residual heat. In some applications, a supplementary burner is provided to support steam production when the available heat is temporarily insufficient.

An HRSG is a specific type of waste heat recovery boiler that recovers heat from the exhaust gases of a gas turbine or engine to produce steam. This technology is often used in combination with combined heat and power units (CHP) and power plants to significantly increase overall efficiency.

Because a waste heat recovery boiler uses heat that would otherwise be lost, these installations are often one of the most cost-effective energy recovery projects. The exact payback period will depend on the available heat, the number of operating hours and fuel prices.

As an EPCS integrator, the Callens Group takes charge of the entire process: from on-site analysis and engineering to installation and service. This gives you a single point of contact throughout the full service life of your waste heat recovery boiler. You can find out more about the various steps in our workflow here.

Dust particles, corrosive components or deposits can reduce heat transfer and thus affect the installation’s efficiency. That is why account is taken of the composition of the exhaust gases during design, and periodic inspections and maintenance are essential.

Yes. In many cases, a waste heat recovery boiler can be integrated into an existing steam plant. The steam produced is then injected directly into the existing steam network. This way, the available residual heat can be put to maximum use without the entire installation having to be replaced. Curious whether your existing infrastructure is suitable for heat recovery? Our experts will be glad to explore the possibilities.

Select your language