Polymer Air PreHeater - APH

- Heat recovery system for flue gas or exhaust air
- Heat up combustion or drying air
- Corrosion and fouling resistant
Corrosion and fouling problems limit recovering additional heat from flue gas or exhaust air
Corrosion problems
Flue gases from burning fuels like refinery gas, fuel oil, off gases, blast furnace gas, oil, coal, biogas and biomass contain acidic elements. When you recover all the heat you will cool the flue gas or exhaust air through the acid dew point. Acids will then condensate which leads to corrosion in conventional metal air preheaters and in the rest of the installation.
Fouling problems
When exhaust air is cooled too deep, fouling may start to accumulate quicker and can eventually lead to blockage of your heat exchanger.
Waste heat can be recovered with air preheaters made with polymer
Heat up combustion air
The polymer APH is used for combustion air preheating on thermal processes. Ambient air is heated up and is fed to the burners. By burning hot combustion air instead of cold combustion air, less fuel is needed to achieve a certain duty. Due to acid condensation, heat recovery from flue gases can be demanding.

Heat up drying air
The heat from exhaust air is recovered and used to preheat fresh ambient air entering the dryer. This saves fuel on the fresh air heater. Due to the high humidity and presence of dust, heat recovery from drying processes can create corrosion and fouling problems.

Benefits of Polymer Air PreHeaters - APH
- Corrosion resistance
The APH contains polymer tube bundles, through which the flue gas or exhaust air flows. The polymer is resistant to the acids that are formed. The polymer can handle H2SO4, HCl, HF, H3PO4 and others.
- Anti-fouling property
The straight flow path of the flue gas through the APH and the low propensity of polymer to bind in combination with the possibility of in-line cleaning make the polymer APH suitable for fouling services.
- Prevention of corrosion in duct and stack
Up to 80% of the acids will be condensed and removed from the flue gas by the polymer APH. This lowers the acid dew point substantially and prevents down stream corrosion.
WHITEPAPER
Corrosive flue gas is no longer a show-stopper for heat recovery
Significant amounts of waste heat in flue gases or exhaust air from dryers, remain untapped due to acid dew point corrosion. Download the whitepaper to find out how to overcome this limitation.
Learn more about Polymer Air PreHeaters - APH
Patented Polymer Honeycomb Technology (PHT)
Standard modules
The polymer APH consists of polymer tubes that are combined into standardized bundles. The bundles are installed in a compact metal casing.
Stability
The individual polymer tubes are interconnected using the Polymer HoneyComb Technology (PHT). This stabilizes the tubes for flow induced vibrations.
Compact and light weight
The 1.5 meter long bundles provide an intense heat exchange process. The PHT technology creates a countercurrent flow path for hot and cold gas streams. Therefor the APH is compact and light weight.

Designed for perfection
Even distribution of temperature
The polymer APH is designed using Computational Fluid Dynamics to ensure homogeneous air and flue gas distribution which ensures maximum performance of the air preheater under all conditions. Due to the even distribution of the flow, the temperature of the flue gas coming out of the APH is everywhere the same.
No dead zones
The vertical downward flow of flue gas or exhaust air ensures proper drainage of condensate. Both gas and condensate flow in the same direction assisted by gravity. There are no baffles or turns where fouling can accumulate.
Disengagement of acids and flue gas
Liquids are separated from the cooled flue gas flow in the bottom segment of the polymer APH. Liquids are removed via a drain.
Easy cleaning and maintenance
Cleaning with water
The polymer APH can be easily cleaned manually when you open the top lid during a stop. There is also the possibility to install an inline cleaning system. Each bundle has its own spray nozzle, which can clean the bundle during operation.
- Cleaning frequency adjusted based on process conditions
- Bundle design and drain for easy drainage of washing liquids
- Smooth polymer surface prevents fouling

Maintenance
Maintenance of the polymer APH is easy.
- Regular visual inspection during stop is sufficient
- Retraction of the polymer bundles for washing or inspection in case of heavy fouled equipment
- The low weight of the bundles make it easy to handle them without a crane

VIDEO
Cleaning and Maintenance
Polymer Air PreHeater
In this video we show you how to remove bundles from the polymer Air Preheater (APH), and how to inspect and clean them.
Learn more about the maintenance and cleaning of the Polymer Air Preheater
MANUAL
Download Operating & Maintenance manual
INFOSHEET
Condensate treatment
Technical details
Operating range
F: | 5.000 - 500.000+ kg/hr |
Tdesign: | 200 °C |
Pdesign: | 150 mbar |
ΔP: | ~6 mbar |
For operating temperatures above 200 ÂșC a combination of a metal APH in series with a polymer APH is applied.
Thermal expansion
The polymer APH is designed in such a way that the polymer bundles can thermally expand without stresses acting on the polymer tubes. The air preheater can be heated-up and cooled down instantaneously. There is no time dependent heating profile required.
Dimensions
Materials
The casing has four segments (see schematic overview above). The construction material can be selected for each segment of the air preheater individually based on the application.
Receive all technical details required for the installation concept
INFOSHEET
Polymer Airpreheater Installation concepts
Polymer Air PreHeaters are suitable in these industries and thermal processes
Your path to lower CO2 emissions, energy consumption and costs

Technical assessment
Our process engineers assess the technical feasibility of additional heat recovery on your process. The potential reduction in CO2 emissions, energy consumption and costs is determined.

Heat exchanger design and Business Case
A proposal is made with all technical details and economic assessment with payback time. You have everything you need for budget approval.
Realize project delivery
FAQ's
What is the maximum temperature the polymer APH can withstand?
The design temperature of the polymer APH is 200 ÂșC. When you have a higher flue gas temperature, a combination of a metal and polymer APH can be installed.
What aspects do I need to consider when installing the polymer APH in my plant?
Most important is the assessment of the thermal balance, hydraulics and lay-out. A checklist with more details can be provided upon request. Please send us an email.
Can the polymer APH be used to heat-up a water stream?
No, the APH is only for gas-gas heat exchange. The polymer ECO can be used to heat-up a water stream.