improve quality.
Increase line speeds.
Boost output.



  • Improve quality and consistency with better inspections.
  • Reduce water marks and corrosion.
  • Speed up production – boost output.
  • Improved drying delivers better quality products faster.

Why Use Air Knife Systems?

Air knives create high-velocity and precision-targeted jets of air that will:

  • Improve quality and consistency with better inspections.
  • Reduce water marks and corrosion.
  • Speed up production – boost output.
  • Improved drying delivers better quality products faster.

Remove The Weak Link In Your Metal Processing

Don’t let old inefficient dryers slow down your production of sheet steel, aluminium, zinc, and other metals. Old and badly configured drying systems can and do impact quality and energy costs especially if you’re still using compressed air – a self-inflicted air leak that costs a fortune (despite being supposedly ‘free’).

Poor-quality dryers that have failed to keep pace with increasing line speeds can have a devastating impact on product quality and consistency. They can badly affect your electronic inspections that are so vital in ensuring quality.

But too many rolling mills are compromised by poor quality air drying systems because the cycle for investing in new stands is so long. Many steel producers make the mistake of waiting until their next refit to review their air dryers – instead of taking swift action that could improve quality, increase output, reduce energy bills and deliver a solid return on investment.

ACI Metal Processing - Rolling Mill
ACI Air Knife for Metal Processing

Safeguard Your Electronic Quality Inspection Systems – Ensure Quality/Consistency

Vision-based metal surface inspection systems are vulnerable to moisture. Without protection from the correct drying systems, their performance will be compromised by steam or water.

Defect-detection systems above and below the line can be impacted by water/coolant spray, oil droplets or clouds of steam. That can result in false positives as the vision systems scan for blemishes, scarring, cracks, and other defects.

Custom-designed air knives and axial fans create protective barriers of air to protect your vision systems from contamination that can affect their accuracy, compromise sheet metal quality, and reduce output.

These air dryers integrate with your existing systems to ensure that as much water/coolant as possible can be recycled and reused – conserving resources for maximum efficiency.

Air Knives For Rolling Mill Clean Down Processes

Accurate, precise, and efficient drying is crucial during every clean down stage. Moisture cannot be allowed to dilute the solutions used in pickling, galvanising, painting, or any other treatments.

Chevron air knives are the most effective method because they cut through surface moisture like a snowplough – halving the distance that the water droplets need to travel. This speeds up drying, saves energy and enables faster line speeds.

Straight-edge air knives are recommended only for lines where the strip is <1 metre wide. Chevron air knives are essential for strips wider than one metre.

To find out more about air knife systems and air knife technology, view our detailed guide. 

You will find information about:

  • how air knives are 90% more cost-effective than compressed air systems – as well as being quieter, cleaner and safer
  • the ROI, productivity, quality and operational benefits of air knives
  • materials, construction and nozzle options
  • how we learn your precise requirements before providing a detailed quotation
  • technical drawings of standard ACI air knives (custom designs are also available)
  • reciprocating air nozzles (including technical drawings)
  • blower-powered de-ionisation air knives (and how they work)
  • acoustic enclosures and support frameworks
  • modular ducting and flexible hose
  • turnkey conveyor systems with integrated air knives
  • cable and wire drying systems (with technical drawings)
  • spiral drum dryers for small/light components (with technical drawings).

Air Knives For Hot And Cold Rolling Mills

Dedicated air knives for rolling mills are significantly different to those used in other industries such as food production or canning/bottling.

Rolling mill air drying systems are always custom configured. The fans, blowers, ducting and manifolds are usually tried and tested standard components – with all the proven performance and cost benefits that come with specifying off-the-shelf equipment.

But the air knives are almost always custom-designed. This is because there are so many variables involved in developing drying solutions for rolling mills: no two are alike. These variables can include the:


  • line speed – based on the width of the metal sheet being rolled
  • temperature of the sheet metal – moisture can sit on a gas barrier when the metal is very hot
  • condition of the services between stands – and whether they are leaking oil
  • performance of the cooling system – and whether it is over-delivering water/coolant
  • efficiency of the cold rolling processes such as etching, painting and other treatments.

Burrs from trimming can affect drying performance. Burrs hold moisture, making it harder to dry the metal sheet.

Any drying system installed in a rolling mill must be extremely robust. It has to withstand challenging and hazardous working conditions – including hits from ‘coil ups’. For this reason, rolling mill air knives are fitted with protective gussets. They can also be mounted on chains to better absorb the impact of being struck by coils of metal.

Stop Using Expensive Compressed Air

Few rolling mills still use compressed air to dry sheet metal. Far from being the ‘free fourth utility’, compressed air is very expensive and inefficient. It also carries significantly higher health and safety risks.

But our engineers still come across the occasional compressed air system – usually on rolling mill lines that are under 500 mm. Or where the customer has tried to create a DIY solution to an urgent drying issue.

Replacing your old compressed air dryer with a proper air knife system is a sure-fire way to cut your costs. Guaranteed. It’s a no-brainer.

Compare advanced ACI blower-driven air knives vs costly compressed air.

You will discover:
• the downsides of compressed air
• payback analysis – how much money you could save.

Contact us now if you are still using compressed air to dry your sheet metal.

ACI Metal Processing Strips

ACI Air Knife Systems For Metal Processing

Decades of experience in supplying bespoke air drying systems to rolling mills have shown that testing is essential. That includes:


  • scale testing your new system in our laboratory
  • loaning you demo equipment so you can test it on-site to prove the technology works
  • fine-tuning the completed system to ensure optimum performance.

Air Knives For Other Forms Of Metal Processing

  • Profile drying – air knives are a proven solution for this application. Fast, efficient air knives dry the profile once any coolant and/or lubricant has been washed off the surface. They can also dry extruded profiles that have been quenched to set their shape.
  • Tube drying – ring air knives are the typical solution for drying tubes after the removal of coolant/lubricant. But on occasion, we have used other types, depending on the diameter of the tube.
  • Bar drying – air knives are a quick and effective way to dry metal bars after the removal of coolant/lubricant.
  • Shot blasting and peening – specify air knives and nozzles to remove shot and debris sitting on the surface of the material.
  • Water jet cutting – air knives blow away water left on the surface of the sheet/product. For complex shapes, air knives and nozzles can be used after the cutting.
  • Rolled steel joists (RSJs)/I-beams/universal beams – air knives and nozzles are used in two main applications:
    – after shot blasting/peening
    – to remove the swarf from machining processes.

Use ACI’s clean air solutions to solve your metal processing challenges – improving quality and creating efficiencies.

Why ACI?

50+ years of technical expertise
and experience.

World-class solutions –
US (Maine) subsidiary. Distributors,
agents and partners in 40+ countries.

Performance guaranteed – all standard and custom systems will perform as tested and specified. Guaranteed results and savings.

Advanced quieter air blowers
that take up less space.

UK designed and
manufactured equipment.

Thousands of happy customers
across the world.

How ACI has helped businesses like yours.
Metal processing case studies:

Corus Trostre

Corus Manufacturing

How Corus replaced a compressed air system costing £75,000/year for an ACI air knife system that achieved payback in just 21 weeks.

Read More…



How ThyssenKrupp used ACI air knives to cut blower energy consumption by 50% and eliminate the need for steam-powered air heating.

Read More…


Denso Manufacturing

How Denso Manufacturing switched from compressed air to ACI air knives to improve quality – and get a good return on investment.

Read More…

Talk to us about your requirements


We will ensure you get the best drying solution for your system by providing industry-leading advice and guidance.

Call our team at +44 (0)1297 630960 or email us below.