Steam boiler in a combined set-up

Not every steam demand can be met with a single boiler or fuel. If you have multiple energy sources or want to make your steam supply more sustainable step by step, a combined set-up is a good choice.

By combining different steam boilers — each with their own energy source — you create a flexible steam supply that meets both the technical and economic challenges.

The Callens Group specialists design combined set-ups tailored to your specific situation and future plans.

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When is a steam boiler in a combined set-up worthwhile?

You may have access to biogas, syngas or waste heat, but not enough to cover your entire steam generation. Or your energy source isn’t always the most cost-effective, such as an e-boiler that runs solely on electricity.

If you still have a well-functioning gas boiler, the step to a combined set-up is a no-brainer. The result is more flexibility and operational reliability.

By combining several steam boilers with different energy sources, you can always run the most cost-effective boiler. This creates a flexible steam supply that responds to changing energy prices, fuel availability, production needs and sustainability targets.

5 reasons to choose a combined set-up

  • You have multiple energy sources on site.
  • You want to combine an existing steam boiler with another steam boiler.
  • You want to be less dependent on a single fuel.
  • You’re looking for maximum operational reliability and redundancy.
  • You want to optimize energy costs.
Callens Stoomketel Combinatie
Outputup to 100 MW
Capacity25 kg/h to 150 t/h steam
Design pressure0.5 to 100 barg
Efficiency99 %+

Technical specifications of steam boilers in a combined set-up

In a combined set-up, we don’t size a single boiler, but a complete steam system. To do so, we look at:

  • your base load
  • your peak outputs
  • operating hours
  • the available energy sources
  • future developments on your site

Our engineers analyze how the various boilers can work together optimally, taking account of steam demand, energy prices, fuel availability and operational reliability.

The result is a flexible steam system that can adapt to changing conditions without compromising on continuity.

advantages

Advantages of a steam boiler in a combined set-up

By combining several steam technologies, you create an energy supply that can better respond to changing market conditions, production needs and sustainability targets.

Maximum flexibility

Individual boilers are used on the basis of technical and economic effectiveness.

Higher operational reliability

Different installations can support or temporarily replace one another.

Less dependent on a single fuel

Companies become less sensitive to price fluctuations or availability problems.

Step-by-step sustainability

New technologies can be added without fully replacing existing installations.

Lower energy costs

A combined set-up allows you to easily switch from one fuel to another in function of energy costs.

More efficient maintenance

Maintenance can be scheduled per installation without shutting down the entire steam production.

Hybride Stoomketels Tiense Suiker 2
Callens Stoomketel Combinatie
Callens stoom combiatie 1
Callens stoom HRSG 1
Hybride Stoomketels Tiense Suiker 2
Callens Stoomketel Combinatie
Callens stoom combiatie 1
Callens stoom HRSG 1
Hybride Stoomketels Tiense Suiker 2
Callens Stoomketel Combinatie
Callens stoom combiatie 1
Callens stoom HRSG 1
Hybride Stoomketels Tiense Suiker 2
Callens Stoomketel Combinatie
Callens stoom combiatie 1

What’s the difference between a combined set-up, a dual-fuel boiler and a hybrid steam installation?

These terms are often used interchangeably, but they refer to three different concepts.

A hybrid steam boiler

A hybrid steam installation combines different fuels in a single boiler. The best-known version is the steam boiler with a gas burner combined with electric heating elements. Intelligent control automatically determines which fuel is the better option at any given moment.

A steam boiler in a combined set-up

A combined set-up consists of two or more separate steam boilers, each connected to its own energy source. Together they cover your total steam demand. For example: a gas-fired steam boiler combined with a biogas boiler or a hydrogen boiler.

A dual-fuel boiler

A dual-fuel boiler is a single steam boiler with a single burner that can automatically switch between two fuels — think natural gas and (bio-)oil.

Callens Service Onderhoud 10

Maintenance of your steam boiler in a combined set-up 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 is 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 about our service contracts
partnership

Why partner with Callens Group?

60 years of experience in EPCS projects

An independent integrator focused on your specific needs

Flexible project execution

Short decision-making lines and a personal approach

Unique service & maintenance support

With 13 locations, always close by

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

Projects with steam boilers in a combined set-up

IMG 7282
Heat technology Steam boilers Combined set-up +1

Steam and central heating boiler: smart combination for greater efficiency

Output2,000 kg/h
Operating pressure6 barg

What is your challenge?

 We’ll find a solution. With more than 400 experts in-house, no question goes unanswered.

Challenge us

Questions? We have the answers.

Callens verving een verouderde stoominstallatie door een volledig nieuwe stookplaats met een HRSG-gasturbine en een back-upstoomketel. De nieuwe installatie zorgt voor een stabiel stoomnet en een betrouwbare procestemperatuur, cruciaal voor het raffineren van oliën en vetten. Dankzij de integratie van moderne technologieën werd de installatie efficiënter, performanter en rendabeler. Ook de ergonomie en onderhoudsvriendelijkheid kregen bijzondere aandacht, met vlotte toegang tot alle componenten en veilige hijsvoorzieningen. De back-upinstallatie heeft een capaciteit van 23 ton stoom per uur en werkt op aardgas.

Ontdek hier alle projectdetails.

Omdat meerdere stoomketels beschikbaar zijn, blijft de stoomvoorziening doorgaans operationeel wanneer één installatie tijdelijk buiten dienst is voor onderhoud of een storing. Dat verkleint het risico op productieverlies aanzienlijk. 
Bent u op zoek naar meer redundantie binnen uw stoomvoorziening? Vraag advies aan onze experten.

Als EPCS-integrator neemt Callens Group het volledige traject op zich: van on-site analyse en engineering tot installatie en service. Meer info over de verschillende stappen in onze workflow vindt u hier. 

Dat hangt af van verschillende factoren, zoals de beschikbare energiestromen op de site en de reeds bestaande aansluitingen. Veel voorkomende combinaties zijn aardgas met elektriciteit, biogas, syngas, waterstof, restwarmte of afgassen uit een WKK of productieproces. De meest geschikte configuratie wordt bepaald op basis van de technische en economische context van de site. 
Benieuwd welke configuratie interessant is voor uw bedrijf? Onze experten berekenen het voor u.

Ja. In veel gevallen wordt een bestaande stoomketel behouden en aangevuld met een bijkomende technologie, zoals een e-boiler, biogasgestookte ketel of afgassenketel. Zo kan de bestaande investering maximaal worden gevaloriseerd terwijl de stoomcentrale verder wordt verduurzaamd. 
Wilt u weten welke uitbreidingsmogelijkheden er zijn voor uw huidige stoomcentrale? Vraag het aan de experten.

A backup boiler is mainly used when the main installation fails or is being serviced. In a combined set-up, several steam boilers actively contribute to steam production. Depending on energy prices, fuel availability and heat demand, you can switch to the most suitable boiler at any time.

Yes. In many cases, an existing steam boiler is retained and supplemented with an additional technology, such as an e-boiler, biogas-fired boiler or waste heat recovery boiler. This maximizes the value of the existing investment while making the steam plant more sustainable. Want to know what expansion options there are for your current steam plant? The Callens Group specialists will be happy to explore them with you.

That depends on various factors, such as the available energy streams on site and the existing connections. Common combinations are natural gas and electricity, biogas, syngas, hydrogen, waste heat or exhaust gases from a CHP unit or production process. The most suitable configuration is determined based on the technical and economic context of the site. Curious which configuration is worthwhile for your company? Our experts will be glad to look into it for you.

The installation’s control system takes account of factors such as current steam demand, fuel availability, energy prices and the desired operating strategy. Based on that, it automatically determines which boiler or combination of boilers can be used most efficiently.

Absolutely. By combining several boilers with different outputs, steam production can be matched more precisely to actual demand. This avoids unnecessary energy consumption and increases the installation’s efficiency.

Yes. One of the major advantages of a combined set-up is that new technologies can be added later. For example, a company can start with a gas-fired steam boiler and integrate an e-boiler, biogas boiler or hydrogen boiler over time.

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 steam boiler in a combined set-up. You can find out more about the various steps in our workflow here.

When multiple energy sources are available, steam demand varies widely, or high demands are placed on operational reliability, a combined set-up often offers more flexibility than a single central installation. What’s more, steam production can be matched to current energy prices and operational needs.

Because there are several steam boilers, steam supply usually remains operational when one installation is temporarily out of service for maintenance or because of a malfunction. This significantly reduces the risk of production loss. Looking for more redundancy within your steam supply? Our experts will be happy to advise you on the possibilities.

Callens replaced an outdated steam installation with a completely new boiler plant featuring an HRSG gas turbine and a backup steam boiler. The new installation ensures a stable steam network and a reliable process temperature — crucial for refining oils and fats. Thanks to the integration of modern technologies, the installation became more efficient, higher yielding and more cost-effective. Ergonomics and ease of maintenance also received special attention, with smooth access to all the components and safe lifting features. The backup installation has a capacity of 23 tons of steam per hour and runs on natural gas.

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