At the forefront of thermal technology innovations and developments, CDS has developed, patented and introduced into the marketplace a ‘new’ concept in process drying “R-O2 Technology”

Using dry superheated steam as the heating medium to replace the traditional air/oxygen methods of drying. This dramatically improves the efficiency of the drying process whilst at the same time using a safe, invisible dry gas being used at atmospheric pressure.

The R-O2 thermal advantages are revolutionising the process drying industry. Achieving validated energy saving against conventional systems, minimal percentage drying losses of product and tremendous advantages in drying cycle times and efficiencies.


R-O2 dryers are uniquely designed to operate in either a conventional mode or super heated steam mode, or a combination of both to optimise the drying cycles.
R-O2 Drying Advantages include:-

  •  Specific heat of steam is twice that of normal air, hence it can transfer more than twice the amount of heat for the same mass air flow.
  • Viscosity of steam is approximately half that of air at the same temperature creating a much greater effect, in particular on difficult shaped products.
  • R-O2 dryers, are designed to operate in a direct ring mode if required. A fully modulating air valve is added to the burner to give stoichiometric control and minimise the oxygen input into the system during the main drying phase.


  • During the R-O2 phase the oxygen is displaced above 100°C with dry superheated steam, which allows the product to be rapidly dried, as the speci c heat of steam is twice that of air, and the viscosity is approximately half that of air, thus providing a greater drying medium.
  • During the R-O2 phase ONLY the temperature is controlled and the additional heating further penetrates into the product and evaporates the remaining water, while the steam generated continues to be vented from the chamber by the moisture expansion.
  • Heating continues until the product is dry at which stage ambient air is introduced into the dryer to cool both chamber and products, via automatically controlled dampers (fresh air and exhaust).
  • The R-O2 cycle has the ability to operate using both the conventional and superheated steam parts of the drying cycles to achieve the optimum cycle for the delicate ceramic products.

In summary, the combination of the conventional control using humidity injection during the warm up phase and rapid moisture removal during the drying phase allows R-O2 drying to achieve substantial reductions in drying times against conventional techniques.


  • The steam is generated from the moisture contained only within the product.
  • When water boils & becomes steam its volume increases by a factor of 1,670.
  • As the water evaporates, each Kg of water occupies a volume of 1.67 m3.
  • R-O2 Dryers operate on full recirculation so no new air is required to enter the system.
  • As both the recirculation mix and the product get hotter, 1.67m3 of increasingly humid air is vented as each Kg of water is evaporated. This process continues until the Dryer is virtually free of air which is replaced with dry superheated steam.


An R-O2 dryer has now evolved to be built in a radically different way to conventional dryers. A number of key build features
now include:-

  • Specially designed main structure and interlocking panel system.
  • Fully welded supply and recirculation ductwork system to eliminate any conventional air or superheated steam gas loss.
  • Specially developed and designed supply and recirculation fans to eliminate air leakage.
  • Much improved door design and ease of operation.
  • Stoichiometric designed modulating gas & air burners.
  • Introduction of atomised water vapour.


The R-O2 benefits recorded by the customers have been as follows:-

  • Shortest possible drying times.
  • Virtually zero percentage drying losses.
  • Best possible energy consumptions, up to 25% less than best recorded conventional drying times.
  • Capability to accept difficult products, much earlier into the dryer, vastly reducing work in progress and consequently saving valuable floor space.


The answer to this question is simple. Anything that can safely tolerate a temperature of above 100°C can be dried in the R-O2 Dryer.

The list of products that can be dried by the R-O2 process is continually expanding and which currently includes;

  • Raw materials; Eg. sand and aggregates
  • Paper sludge
  • Food products
  • Food wastes
  • Timber
  • Waste woods
  • Biomass
  • Municipal solid wastes
  • Various sludges and slurries
  • Laundry
  • Agricultural wastes
  • Industrial wastes
  • Chemicals
  • Pharmaceuticals
  • Animal feeds
  • Animal effluent
  • Bagasse
  • All sanitaryware bathroom products
  • Plaster moulds
  • All types of ceramic bodies
  • Refractory products
  • Insulating bricks
  • Clay Brick

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