Waste Heat Recovery
High Integrity Heat Exchangers & Engineered Solutions for Waste Heat Recovery
Waste heat recovery plays a critical role in improving energy efficiency, reducing operating costs, and lowering carbon emissions across a wide range of industrial sectors. Graham Hart Process Technology designs and manufactures high integrity heat exchangers and waste heat recovery units (WHRUs) to help clients recover and reuse energy that would otherwise be lost.
Whether you are considering stack gas heat recovery, process stream optimisation, or working towards a plant pinch point, we supply engineered solutions tailored to real-world operating conditions.
Our Approach to Waste Heat Recovery
Recovering waste heat successfully is not simply about installing a heat exchanger.
Get it right, and the recovered energy can deliver significant cost savings and efficiency gains.
Get it wrong, and the solution may cost more than the value of the energy recovered, introduce operational risk, or compromise process control.
This is a technically complex field where many interacting factors must be considered. We act as a technical partner, helping clients focus on what truly matters and avoid costly mistakes.
With process modelling and thermal design expertise in-house, our chemical and thermal engineers work collaboratively with you to:
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Understand your process and constraints
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Evaluate realistic heat recovery potential
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Select appropriate technology and materials
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Deliver a solution that is technically sound and commercially viable
Our approach is built around right first time manufacture, ensuring equipment performs as intended from installation through qualification and ongoing operation.
Waste Heat Recovery Capabilities & Key Sectors
We support waste heat recovery across a broad range of industrial environments, including:
- Stack Gas Heat Recovery
Recovering energy from exhaust or flue gases discharged to atmosphere.
- Process Stream Heat Recovery
Optimising heat exchange between process streams to improve overall plant efficiency.
- Energy Efficiency & Decarbonisation Projects
Supporting carbon reduction initiatives through reduced fuel consumption and improved thermal integration.
Stack Gas Heat Recovery
In its simplest form, stack gas heat recovery involves a hot, clean, dry gas stream being cooled to transfer energy to a colder incoming stream.
Clean Stack Gas Applications
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Use of cross-flow or conventional heat exchangers
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Forced convection heat transfer
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Relatively straightforward thermal duty
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Common applications include pre-heating combustion air or process feeds
Challenging Stack Gas Conditions
At the other end of the spectrum, stack gases may be:
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Dust-laden
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Condensing
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Chemically aggressive
In these cases, direct contact heat exchangers may be required, where hot gas passes through a controlled shower of liquid to recover heat safely and effectively.
The Real World
Most applications fall somewhere between these two extremes, where:
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Fouling risk exists
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Gas composition varies
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Corrosion potential must be managed
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Operating conditions change over time
This is where experience and engineering judgement are critical.
Key Data Required for Stack Gas Recovery
To evaluate a stack gas heat recovery solution effectively, we typically require:
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Stack or waste gas flow rate (kg/hr)
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Inlet and outlet temperatures
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Gas composition
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Presence of corrosive species (e.g. halides, chlorides)
Material selection is particularly important; common stainless steels may be unsuitable in the presence of certain contaminants.
Equally important is understanding how the recovered heat will be used. The most efficient solutions typically reintegrate heat directly back into the process, such as:
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Pre-heating feed streams
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Supporting upstream thermal duties
As a last resort, recovered heat may be used for lower-grade applications such as space or wash-water heating.
Process Stream Heat Recovery
Recovering heat from within a process requires a holistic view of the entire system.
Identifying the best opportunities for process stream heat recovery involves:
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Mapping heat sources and heat demands
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Understanding temperature levels and pinch points
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Assessing impact on process control and operability
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Evaluating variability and turndown requirements
Upfront planning and early engagement with thermal design engineers can pay significant dividends, delivering:
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Improved energy efficiency
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Reduced fuel consumption
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Lower operating costs
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More stable process operation
Engineering Integrity & Solution Delivery
Waste heat recovery equipment must operate reliably in environments that may involve:
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Fouling and corrosion
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Thermal cycling
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Variable operating loads
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Continuous or long-term service
Our approach combines:
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Robust mechanical and thermal design
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Careful material selection
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Precision fabrication and quality control
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Practical experience of real industrial processes
This ensures solutions are engineered for long-term performance, maintainability, and commercial return.
Why Choose Graham Hart for Waste Heat Recovery Projects?
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Proven experience in waste heat recovery applications
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High integrity heat exchangers and WHRUs
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In-house process modelling and thermal design capability
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Practical understanding of real-world process constraints
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Focus on solutions that deliver genuine value—not theoretical gains
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Collaborative support from concept through delivery
Discuss Your Waste Heat Recovery Opportunity
Do you have a process that is dumping large quantities of usable energy?
Recovering that energy effectively requires the right technical partner.
Our engineering teams can help you assess feasibility, avoid costly pitfalls, and deliver a waste heat recovery solution that works in practice and on the balance sheet.