Exhaust Gas Heat Exchangers
Turning engine waste heat into vital energy
Bowman exhaust gas heat exchangers capture the valuable waste heat in an engine's exhaust stream and put it back to work. Fitting one to a generating set can lift overall efficiency from around 30% to roughly 60% — or beyond 80% when combined with other heat recovery. Fully welded stainless steel, for engines up to 1MW.
Recover the Heat Your Engine Throws Away
An exhaust gas heat exchanger is one of the most effective ways to reclaim waste energy from an engine-powered gen-set. Around 55% of an engine's recoverable waste heat leaves through the exhaust, and a Bowman unit transfers that energy into a water circuit so it can be used for heating, hot water, process heat or power generation rather than being lost up the stack. Suitable for engines running on biogas, diesel, natural gas and hydrogen, up to 1MW.
Every unit is based on Bowman's proven shell-and-tube design, combining excellent heat transfer with easy installation and simple maintenance. The fully welded, all stainless steel construction stands up to extreme exhaust gas temperatures, while automated tube-end welding with 100% inspection guarantees the integrity of the tube core. All flanges are PN6 to BS EN1092, and each unit ships with a pressure relief valve, drain plugs, vent and sensor bosses, and mounting brackets as standard.
Bowman exhaust gas heat exchangers are at work in some of the most demanding installations on earth — from Combined Heat & Power systems serving district heating, to thermal oil heating, ORC and Stirling-engine generation, and absorption chillers. As the Australian distributor for Bowman, Luxfords backs every unit with qualified engineers and maintenance workshops on both coasts.
Why Choose Bowman Exhaust Gas Heat Exchangers?
All Stainless Steel
Fully welded stainless steel throughout delivers maximum reliability when handling extreme exhaust gas temperatures.
Proven Shell & Tube
Bowman's renowned shell-and-tube core combines excellent heat transfer with simple installation and maintenance.
Three End-Cover Options
Choose units without end covers, straight PN6 covers, or rotatable right-angle covers for flexible installation.
Built-In Pressure Relief
A factory-fitted relief valve activates if water-side pressure exceeds 4 bar, protecting the unit and system.
Model Range & Performance
Typical heat recovery across the range. Figures are examples based on a natural gas engine with 600°C exhaust gas and 80°C water; intended as a general guide.
| Model | Typical Engine Power | Exhaust Gas Flow | Heat Recovery | Gas Pressure Drop |
|---|---|---|---|---|
| 2-25 | 16 kW | 1.2 kg/min | 9.5 kW | 1.6 kPa |
| 3-32 | 32 kW | 2.4 kg/min | 19 kW | 1.2 kPa |
| 4-32 | 60 kW | 4.5 kg/min | 36 kW | 1.0 kPa |
| 5-32 | 90 kW | 6.7 kg/min | 55 kW | 1.0 kPa |
| 6-32 | 140 kW | 10.5 kg/min | 85 kW | 1.0 kPa |
| 8-32 | 250 kW | 18.7 kg/min | 151 kW | 1.0 kPa |
| 10-32 | 400 kW | 30.0 kg/min | 241 kW | 1.1 kPa |
| 12-32 | 600 kW | 45.0 kg/min | 362 kW | 1.1 kPa |
| 15-32 | 950 kW | 70.0 kg/min | 563 kW | 1.0 kPa |
Each frame size is available in multiple lengths (e.g. -32, -40, -60) for higher heat recovery and lower gas outlet temperatures. Water temperature must not exceed 110°C at 4 bar; gas inlet below 0.5 bar and 700°C. Full range and dimensions in the brochure.
Materials & Construction
Bowman exhaust gas heat exchangers use fully welded, all stainless steel construction throughout, chosen specifically to withstand the extreme temperatures of an engine exhaust stream and to deliver maximum reliability and long-life durability.
The tube core is produced using automated tube-end welding with 100% inspection, ensuring consistent quality and structural integrity at the most critical part of the unit. End cover and shell-side flanges are PN6 to BS EN1092.
Correct Installation
Units must be installed horizontally and accurately levelled with the water connections on top, so the unit always stays full of water, and connected for counter flow. Position the exchanger below the level of the cylinder head so water cannot leak back into the engine in the unlikely event of a tube leak. Fully vent the water circuit, fit automatic engine shutdown with temperature probes, and never remove the pressure relief valve. For diesel engines, exhaust gas temperature should not fall below 180°C. Units are designed for steady-state operation.
Servicing & Parts
Servicing is straightforward — unbolting the end covers or access plates gives full access to the tube plates for cleaning. Always use new gaskets on reassembly. A comprehensive range of replacement parts is available, including end covers, gaskets, pressure relief valves, feet and drain plugs. Luxfords supports every unit in Australia with maintenance workshops on the east and west coasts.
Applications
Antarctic Research — Halley VI
Bowman units form part of the CHP system supplying life-saving energy to the British Antarctic Survey's Halley VI station, where winter falls to −50°C.
Grain Drying — Finland
A closed-loop grain drying system using Bowman waste heat recovery halved fuel use at a Finnish farm, saving around 18,000 litres of diesel a year.
Distributed Power — USA
Bowman heat exchangers sit at the heart of technology that captures exhaust waste heat and converts it into additional electricity.
Cogeneration — Canada
Bowman units in a cogeneration system have halved energy costs for the remote off-grid community of Fort Providence, where winter hits −40°C.
Get the Right Unit, First Time
To recommend the correct exchanger using Bowman's selection programme, please provide:
- Exhaust gas mass flow rate (kg/min) — specify mass flow, not volume flow
- Maximum allowable pressure drop (kPa)
- Exhaust gas inlet and desired outlet temperature (°C)
- Cooling water temperature (°C)
- Cooling water flow rate (l/min) and source
Our qualified mechanical & heat-transfer engineers are here in Australia to help you select and specify the right unit.
Enquire About Exhaust Gas Heat Exchangers
Talk to a Heat Transfer Specialist
Need help choosing? Our team can match the right Bowman exhaust gas heat exchangers to your exact application.