Furnaces
Home / Expertises / Tecnhology / Furnaces
General criteria for designing furnaces
Furnace design is one of the most critical aspects of ensuring overall system performance.
At W.T.E. Waste to Energy, we adopt a rigorous approach, guided by established criteria and a three-phase process, to develop efficient and versatile solutions capable of meeting complex and ever-changing operational needs.
Fuel Variability
Every project should begin with a thorough analysis of the materials to be treated: waste and biomass vary over time and in composition. This is why we design furnaces capable of handling heterogeneous fuels, even those with low calorific value or seasonal availability, ensuring consistent performance and maximum flexibility.
Stable Flows
Stabilizing the flue gas flow is essential to optimizing the entire system: it improves purification efficiency, ensures continuity in steam and electricity production, and reduces wear and tear and oversizing of thermal cycle equipment.
Constant Temperature
Maintaining a stable temperature in the post-combustion zone is crucial to contain NOx emissions, limit the formation of unburned materials, prevent ash melting, and protect materials and linings, ensuring system efficiency and longevity.
General criteria for designing furnaces
From theory to operational configuration
Furnace design always begins with a combustion diagram: a tool that correlates fuel flow, its energy content (LHV), and the thermal power developed.
This is the first document we share with our clients, as it allows them to immediately assess the current and future composition of the fuel mix and define the degree of flexibility required for the system.
Greater flexibility may impact the initial cost of the system, but it allows the use of low-calorific value fuels—often cheaper—with clear economic advantages.
Once validated, the diagram becomes contractually binding and forms the technical basis for subsequent phases of the project.
Adiabatic degree of the furnaces
This indicates how much of the energy released remains inside the furnace. The value can range from 0 (completely non-adiabatic) to 1 (completely adiabatic), and represents a balance between efficiency and control. Depending on the fuel characteristics and the project objectives, we design the adiabatic level best suited to the system.
Non-adiabatic furnace
Integrated into the boiler and constructed with water-cooled tubular walls, it is currently the most common solution in incineration plants. It guarantees excellent energy performance thanks to low smoke production and offers good temperature control in the combustion chamber. However, it is less flexible when using fuels with variable energy characteristics.
Adiabatic furnace
Fully lined with refractory material, it is the ideal choice for handling fuels with low energy content or high humidity. In the basic version, cooling occurs via air blowing, which has a negative impact on energy efficiency.
Compared to a furnace with tubular walls, it is less efficient but offers greater flexibility to fuel variations.
Our optimized design solution recirculates exhaust gases instead of using air, improving performance to levels comparable to those of a non-adiabatic system.
Furnace modeling
Using proprietary mathematical models, we analyze in detail the thermo-fluid dynamic behavior of the furnace-boiler system. This phase allows us to optimize the design, prevent inefficiencies, and reduce environmental impact.
The analysis includes key aspects such as:
- The thermodynamic equilibrium of combustion;
- The geometry of the furnace;
- Heat exchange through the walls;
- Air and flame temperatures;
- Flue gas residence time and oxygen content;
- Pollutant formation;
- The amount of gas to be recirculated.
Each parameter is evaluated to ensure high performance, operational safety, and compliance with regulations.
General criteria for designing furnaces
From theory to operational configuration
Furnace design always begins with a combustion diagram: a tool that correlates fuel flow, its energy content (LHV), and the thermal power developed.
This is the first document we share with our clients, as it allows them to immediately assess the current and future composition of the fuel mix and define the degree of flexibility required for the system.
Greater flexibility may impact the initial cost of the system, but it allows the use of low-calorific value fuels—often cheaper—with clear economic advantages.
Once validated, the diagram becomes contractually binding and forms the technical basis for subsequent phases of the project.
Adiabatic degree of the furnaces
This indicates how much of the energy released remains inside the furnace. The value can range from 0 (completely non-adiabatic) to 1 (completely adiabatic), and represents a balance between efficiency and control. Depending on the fuel characteristics and the project objectives, we design the adiabatic level best suited to the system.
Non-adiabatic furnace
Integrated into the boiler and constructed with water-cooled tubular walls, it is currently the most common solution in incineration plants. It guarantees excellent energy performance thanks to low smoke production and offers good temperature control in the combustion chamber. However, it is less flexible when using fuels with variable energy characteristics.
Adiabatic furnace
Fully lined with refractory material, it is the ideal choice for handling fuels with low energy content or high humidity. In the basic version, cooling occurs via air blowing, which has a negative impact on energy efficiency.
Compared to a furnace with tubular walls, it is less efficient but offers greater flexibility to fuel variations.
Our optimized design solution recirculates exhaust gases instead of using air, improving performance to levels comparable to those of a non-adiabatic system.
Furnace modeling
Using proprietary mathematical models, we analyze in detail the thermo-fluid dynamic behavior of the furnace-boiler system. This phase allows us to optimize the design, prevent inefficiencies, and reduce environmental impact.
The analysis includes key aspects such as:
- The thermodynamic equilibrium of combustion;
- The geometry of the furnace;
- Heat exchange through the walls;
- Air and flame temperatures;
- Flue gas residence time and oxygen content;
- Pollutant formation;
- The amount of gas to be recirculated.
Each parameter is evaluated to ensure high performance, operational safety, and compliance with regulations.
Want to know how we can support your project?
We’re always ready to listen to new ideas, take on new challenges, and find customized solutions together.