Key Benefits

  • Effective heat recovery
  • Reduced material losses
  • Versatile
  • Low maintenance

A cooler that aims to optimise performance

At FLSmidth, we understand the common difficulties faced by the pyro-processing industry concerning indirect coolers, including maintenance issues, poor heat transfer performance, and a lack of adequate temperature control. These problems can compromise the efficiency and operability of your process, resulting in lower availability and higher Opex.

However, with our Indirect Rotary Cooler, we offer a product which aims to minimise maintenance, while optimising the performance at your plant. Instead of using ambient air to facilitate direct contact cooling, the material is cooled indirectly via cooling water that flows over the outside of the rotating shell. This equipment can be applied in any situation where a hot product must be cooled before it can be handled safely, and is suitable for many different materials, including:

  • Calcined spodumene
  • Acid roasted spodumene
  • Alumina
  • Activated Carbon
  • Rare Earth Compounds
  • Manganese Oxide
  • Coke
  • Metal Scraps
  • Pigments
  • Metallic Oxides

Unlike others on the market, our process design expertise has allowed us to properly size the cooler for optimum performance and to interface the cooler properly with upstream and downstream systems. This promises you a method of cooling that will allow for optimisation of your pryo process, making us your ideal choice for indirect rotary coolers.

A cooler that offers affordable and flexible benefits

Our indirect rotary cooler offers numerous advantages that are designed to optimise your plant. From affordability to flexibility, you really can’t go wrong with this equipment.

Effective heat recovery

The remaining heat gathered from the cooling process can be used for secondary purposes, such as hot water, which can be utilised in other sections of the plant. This means that both energy consumption is reduced – thus reducing operational costs – and processes at your plant are less wasteful.

Reduced material losses

As our indirect rotary cooler does not require vents like other rotary coolers, there is no entrainment of fine solids or circulation back to the pyro system. Also, as the cooler is designed with limited contact with the air, product oxidisation is avoided.


The indirect rotary cooler can handle a wide range of materials and particle sizes, allowing you to process the materials you need without fear. The cooler can also be made into a hybrid design with direct water spray and external shell water cooling in order to limit the size of the unit while achieving rapid cooling rates. This gives you the flexibility to choose the design that best suits your plant.

Low maintenance
Past maintenance issues with rotary cooler technologies are avoided with our indirect rotary cooler, as its rotating shell is made from corrosion-resistant materials, meaning that it is highly durable. It also comes with numerous support components, designed to keep maintenance to a minimum.

Features that optimise safety and durability at your plant

The features available with our indirect rotary cooler aim to optimise your facility, via keeping longevity and safety concerns in mind.

Durable shell

Our rotary cooler utilises a stainless-steel shell to avoid corrosion-damage. In cases where a material that is hotter than standard temperatures enters the cooler, a refractory lining in the inlet section can be installed to handle the material until it has reached the correct temperature, resulting in further durability.


“Flooded” design

As the indirect rotary cooler uses water to process materials, it has been made sure that the water is distributed correctly, to avoid hot shell areas and water vapourisation, which can result in high water consumption.


Emission prevention equipment

To prevent dust emissions, the inlet and discharge hoods are supplied with the proper sealing between the hoods and rotary shell necessary to minimise exposure.


Adjustable cooling

The rotational speed of the rotary cooler can be adjusted to control the solids residence time to maximise cooling. Zone cooling can also be implemented to improve product discharge temperature control.


Safety precautions

Our indirect rotary cooler has been designed with the safety of your workers in mind. To prevent injury, we have installed guarding around all of the high-speed rotating equipment and pinch-points, and to prevent burns, the water-cooling section is fully enclosed to minimise exposure to the hot water. An auxiliary backup drive is also available to allow for continued rotation in the event of a power outage.

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