CDS R-02 Thermal Processing Presentation

1. D RY I NG & C U R I NG T E C H NO LOG Y
FO R
CERAMICS, REFRACTORIES,
ADVANCED CERAMICS AND ALLIED PRODUCTS
Presented by:-
Andrew J Hall, President of CDS Inc. NJ, USA

2. History
Privately owned and formed in 1983.
Based in Stoke-on-Trent, England and New Jersey U.S.A.
Curing and Drying Systems Specialists
80 people employed throughout the CDS Group,
covering:
Sales
Design
Engineering
Fabrication, and Installation
Commissioning
Accredited to ISO 9001/2000.

3. Curing & Drying Technologies Available
Conventional H & V Systems with basic
Temperature and Air Change Systems
Advanced H & V Systems with Full PID
Temperature and Air Change Systems
Vacuum
Microwave

4. Pros and Cons of the
Curing & Drying Technologies Available
Conventional H & V Systems with basic Temperature and Air Change Systems
are Extremely Low Technology very Energy Hungry, extended drying cycles
poor quality of product and Sometimes Unsafe
Advanced H & V Systems with Full PID Temperature and Air Change Systems
are A major improvement on the above. With the correct Controls and Safety
equipment this can be a much better alternative.
Vacuum is expensive to operate and the integrity of the oven structure has to
be well maintained
Microwave is and excellent curing / drying process in theory. But the capital
cost, safety issues and electrical operational usage has its limitations on
many processes especially with large scale production operations.

5. The CDS Alternative for
Curing and Drying…..
This being the
or REDUCED OXYGEN !!

6. What is R-O2 Drying?
So to reduce the Oxygen content we need to
replace the air…
SO HOW DO WE DO THIS???
R-O2 Curing / Drying is a method of drying which
uses dry superheated steam at atmospheric
pressure to perform the curing / drying
process.

7. WHAT IS DRY SUPERHEATED
STEAM?
Basically superheated steam at atmospheric pressure is
an invisible dry gas with a temperature of above 100°C -
(212 °F)
The best analogy is to visualise a domestic kettle, which
when boiling emits steam from the spout. The steam
only becomes visible when it condenses on contact with
the surrounding atmosphere as it exits the spout. This is
witnessed by viewing the spot immediately at the tip of
the exit spout, there will be small area where the steam
is invisible, because at that location the temperature is
more than 100°C - (212 °F). This is dry superheated
steam.

8. HOW CAN SUPERHEATED STEAM
BE USED FOR DRYING?
Steam is ‘wet’, how can it dry anything?
When water is boiled it becomes steam at
100°C - (212 °F) When steam is heated to above
100°C - (212 °F) it becomes dry superheated
steam and, like air, which is simply superheated
oxygen and nitrogen, it can be used as a drying
medium

9. HOW CAN SUPERHEATED STEAM
BE USED FOR DRYING?
Because the specific heat capacity of steam is more than twice
that of air, it can transfer more than twice the amount of heat
for the same mass flow.
The viscosity of steam is approximately half that of air at the same
temperature which enhances its ability to impinge on or percolate
through a moist product thus increasing its drying effect.
DENSITY SPECIFIC HEAT VISCOSITY
CAPACITY
Kg/m3 J/kg/K Ns/M2
AIR 1.29 993 18.3
STEAM 0.8 220 8.7

10. How Does Steam Replace air?
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
Curing / Drying System is virtually free of air which is
replaced with ‘DRY’ superheated steam.

11. How Does Steam Replace air?

12. How Does Steam Replace air?

13. What is the R-O2 Curing /
Drying Cycle?
The R-O2 curing / drying cycle consists of only 2
phases:
- The Warm Heat Up Phase - between ambient and
100°C. - (212°F)
- The Curing / Drying Phase - Above 100°C. - (212°F)
During the Warm Up Phase the small amount of water
evaporated from the product effectively raises the
humidity level. This suppresses undue evaporation and
allows the product to be rapidly heated to 100°C -
(212°F) without rapid shrinkage.

14. What is the R-O2 Curing / Drying
Cycle?
Additional heating further heats the product and
evaporates the remaining water, while the additional
steam generated from the moist product continues to be
vented from the chamber.
Heating continues until the product is dry at which
stage ambient air is introduced into the curing / drying
system to cool both chamber and products.
In summary, the combination of the rapid heating
during the warm up phase and rapid moisture removal
during the drying phase allows R-O2 drying to achieve
such substantial reductions in drying times against
conventional techniques.

15. A Typical R-O2
Curing / Drying Cycle

16. What Are The Advantages of
R-O2 Curing / Drying?
In a superheated steam atmosphere the product temperature quickly attains
the steams 100°C - (212 °F) saturation temperature, eliminating the
moisture’s surface tension and halving its viscosity. This absence of
surface tension assists the surface moisture to evaporate quickly while the
lower viscosity enables the internal moisture to migrate faster to the
products’ surface.
The absence of air / oxygen within a drying process prevents oxidation of
sensitive products and at the same time avoids contamination by
combustion residues occurring during directly heated conventional curing /
drying methods.
The low % levels of air/oxygen within the drying process also prevents the
risk of material combustion or explosion of potentially flammable products,
eg solvents, plastics, etc, when being cured / dried at elevated
temperatures.

17. FURTHER ADVANTAGES OF R-02
SUPERHEATED STEAM DRYING
As the Specific Heat of steam is twice that of air, less Fan power is
required to supply a given amount of heat to the moist product.
R-O2 Curing / Drying is more energy efficient because, not only is fresh air
excluded from the process (which in conventional Dryers needs heating),
most of the heat input can be usefully re-cycled, and is typically around
80% of the total heat input.
In summary R-O2 Curing / Drying is a
SAFE Drying Method
Offers Vastly Reduced Drying Times
Reduction of energy requirements
High thermal efficiency
Smaller Plant Footprint required
Minimal exhaust emissions to atmosphere. Traditional stack is not
needed.
Energy recovery potential
Virtual elimination of the potential explosion and or product combustion
risk

18. WHAT CAN BE DRIED BY USING THE
R-O2 DRYING?
The answer to this question is simple.
Any product or material that can safely tolerate a
temperature of above (212 °F) can be dried / cured in the
‘R-O2’ Dryer
.
Refractory products All Sanitaryware, Bathroom products
Ceramic Insulating Bricks Clay Pipes, Roof Tiles and Bricks
Pottery
Insulation Fibres and Materials.
HT Electrical Porcelain Insulators
Solvent Based Binder Ceramics Speciality Ceramics of all descriptions
Minerals Slurries, Colours, Glazes

19. NON WATER BASED BINDERS!!
With solvent based binder ceramics the R-02
Technology is of equal benefit
The advantages are such that the risk of fire and
explosion is greatly reduced.
The emissions are reduced as the need of excess air is
not required to reduce the LEL
Where possible the gasses from the system can be
condensed instead of being sent to atmosphere or sent
through an RTO system.
With such R-02 Systems in this sector of the market
CDS provides PrevEx monitoring as a safe guard.

20. Isometric Drawing of a
Typical R-O2 Drying Chamber

21. R-O2 Drying Chambers

22. R-O2 Drying Chambers

23. R-O2 Continuous Systems

24. R-O2 Continuous Systems

25. Temperature profile in a
Continuous R-O2 Dryer

26. R-O2 Processing Systems

27. R-O2 Processing Systems

28. R-O2
Research & Development
Facilities

29. R-O2 Trial Plants
We have extensive testing facilities located in
Stoke-on-Trent, UK. These facilities consist of a
wide range of R-O2 processing equipment which
allows us to carry out trials on almost any type of
product, producing trial-sized quantities of up to
1,000 kg/hr.

30. R-O2 Technology
Independent Verification

31. Independent Verification
`Energy Efficiency Best Practice Programme (UK)
Future Practice Final Report 58 by ETSU, Harwell,
Didcot, OX11 0RA, acting on behalf of the DETR
1997. Found: R−O2 Drying offers energy
consumption savings over industry survey averages
of between 60% and 85%.
`R−O2 Drying for Ceramic Products Ceram Research
Report KAIR−IV Final Project Report, J. Fifer (Project
Manager) and T. Evans (Report) 1996: Found:
Savings relating from shorter cycle times and or
reduced product damage; Savings achievable by full
re−use of the R−O2 Dryers exhausted steam energy
and or use of its flue gas energy
CERAM

32. R-O2 References Worldwide
Kermansavi
Dutch Govt
Calortec Se-Shin
Palmex RESCO
Morgan Matroc Kanthal
Cookson Mathey Vesuvius
Ideal Standard Parkinson Spencer Refractories
IFGL & MIR Global Dyson Refractories
Incesa Standard Harbison Walker
Villeroy & Boch Morganite Crucible
Kohler Sanimex Morgan Thermal
Steelite plc Hepworth Refractories
Dudson plc Carborundum
Vista Alegra Ceradyne
Pfalzgraph Norton Ceramics
Harbison Walker Diamond Refractories
Swell Corporation Acme Marls
American Standard Cape Insulation
Aguascalientes CERAM
Jacob Delafon Promat
Celtek ECU National Metalurgical Laborities
Doncasters Marine System Technology
Skamol

33. CDS CONTACT
P.O Box 478, Boonton, NJ 07005
Tel: +1 973 641 6857
Cell: +1 973 641 5663
Email: andy@cds-inc.us.com
Web: www.cds-group.co.uk
Andrew J Hall, President