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Air Dryers

Air dryers – Conditioning an airstream to optimise the performance of a process

A range of industries uses air dryers to optimise the performance of their process. Based on a recirculating system or a straight through arrangement, air is cooled to below its saturation temperature to dehumidify. It is then reheated to obtain the ideal process inlet parameters. 
Sterling Thermal Technology designs and manufactures bespoke air dryer systems to match your process requirements.  

Key benefits


Designed to match the airside pressure requirements of your system, the ducting is gastight to ensure the integrity of the air supply to your process.


Our bespoke design allows us to address a wide range of inlet conditions and produce ideal outlet parameters for your process. High humidity air can be cooled to remove the excess of moisture. We can also offer a range of options for the removal of condensate at the outlet of the cooling section.

Improved efficiency 

The condensate wetting the cooling tube and fin surfaces enhances the cooling heat transfer rate. Reheat can be accomplished using excess heat from other process streams. At Sterling, we optimise the process parameters to make sure the design of each processing stage does not result in additional capital cost outlay.


We increase the fin spacing to take into account the requirement for drainage of condensate ensuring minimal condensate carryover. We also introduce moisture eliminators or coalescer filters where appropriate to maximise condensate removal.


How air dryers work

Dry air is used in a number of applications for processing of materials. A simple application is the drying of products where large volumes of dry air are required. The efficiency of the drying process is highly dependent on the incoming air temperature and relative humidity. Cleanliness and durability are essential, especially where foodstuffs, pharmaceuticals or expensive industrial products and processes are involved.

A recycled stream of air used in a drying process will have high humidity. Using chilled water or possibly a refrigerant, the airstream can be cooled to below the dew point. This results in condensate formation on the finned tube surfaces. To ensure proper drainage of the condensate, a wide fin spacing is used in the compact finned surface. The condensing moisture enhances the surface heat transfer rate compensating for this loss of surface.

The velocity of the air in the duct may be maintained at a low level to minimise carryover of water droplets. As an alternative to this, a demister pad, coalescer filter or spray eliminator assembly may be positioned immediately downstream of the air cooler.

After the air cooler, the airstream has a 100% relative humidity but is at a temperature unsuitable for the drying process. The reheat section may then consist of single or multiple banks of air heaters. These are designed to raise the temperature of the airstream to the optimum processing temperature. This will be determined by the characteristics of the material being processed.

Sterling Thermal Technology designs and manufactures air dryers for a range of applications including spray and fluidised bed drying systems. Configurations, duct sizes and even the materials used in their manufacture are customised to align process, plant layout and process air constraints. The units are manufactured from various grades of stainless steel or aluminium; we frequently use alternative materials at the request of the customer to meet specific process requirements.


As a recognised manufacturer of air dryers , we can help you to get the best equipment for your application.

If you feel you need another type of heat exchanger, visit our products and services page or contact us.

Customised heat exchangers

Over 100 years of design & manufacturing knowledge

Your partner for the entire lifecycle of your business

We know the Sterling Thermal Technology air dryers can be configured to meet specific requirements. Their different fin configurations, in particular, sets them apart. Sterling has a proven record in terms of design flexibility, product durability and working life, which means significant capital cost savings coupled with high operating efficiency for us.

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We customise our heat exchange solution to meet your requirements, so contact us today to discover the right equipment for you.

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