STUDY OF SYSTEM CERAMIC DRYING PRODUCTS
The study , wants to encourage the ceramics drying industry to
invest in reducing energy consumption, through a new drying plant
of a different design than the present, which allows for better
production performance and the highest quality standards.
We will start to briefly describe the process of traditional drying with
all the disadvantages that this entails, in order to highlight the
innovation of our proposal.
The originality of our proposal derives from a new mode of drying
the ceramic product, which is based on processes other than the
traditional ones which require a reduced energy expenditure, and
give rise to a reduced drying time, and then processing in addition
to the performance already mentioned.
DISADVANTAGES OF TECHNOLOGY AND CURRENT
- Drying is one of the most important and delicate phases of the
process of producing ceramic articles and can affect in a
substantial way on the quantity and on the performance. Its
function is to remove water from mixing in a controlled manner so
as to respect the integrity of the piece and its dimensional
regularity. It is a very complex process, which has to be managed
carefully in order to avoid unacceptable deformations or breakages.
Currently the process is mainly implemented through driers super
rapid, consisting in conveying a flow of hot air in a direction
transverse to the advancement of the material because with this
arrangement ensures a high air temperature and drying it promotes
rapid migration of ‘water from the center to the surface of the piece.
Unfortunately with this technology you do not have the possibility to
decrease the drying time by increasing the temperature of the hot
air because it will form a surface crust which would not allow
internal moisture to escape, thus compromising the integrity of the
product. It ‘well known that the water to be removed by evaporation
from mixing, presents high values of specific heat (4.2kJ / kgK) and
latent heat of evaporation (2500kJ / kg). Fig.1 shows that currently
up to 50% of the energy of the production process of ceramic
materials is used in drying. In special cases through suitable
measures to Hoc as those listed here you can reduce energy
consumption up to 45%:
- Control of the ventilation system-combustion as a
function of temperature and humidity in different areas
of the dryer.
- The use of air drying at lower volumes but at a higher
temperature so as to reduce the losses of the fireplace
and to speed the drying cycle especially at the entrance
of the pieces in the drier.
- Addressing of the air flow drying through the holes of the
- Use software to simulate the drying process, so as to
control the operational data by remote control, they are
a good way to improve drying.
- The connecting pipe between the furnace and dryer,
deve’essere well insulated; We still need to do a cost
benefit analysis to optimize the thickness of the
insulation system to reduce heat loss.
There are still other strategies to try to optimize energy
consumption and to ensure drying times quite reasonable, but it
was found that in all cases there is approaching the upper limit to
the energy of 3200 kJ / kg
ll the devices mentioned above are useful as long as the ceramic
product to be dried has a geometry is not very complex.
Unfortunately the current ceramic production is moving towards
products of varying thicknesses and geometry, where the heating
by convection above described causes a further lengthening of the
drying times over the lowering of the quality standards expected.
The figure 2 also shows the lowest energy costs (heat and
electricity) achieved by optimizing the heat flow and air drying
It is apparent that to decrease the amount of water in the ceramic
body increases the energy, this is due to the fact that it is inside
water which is more difficult to make evaporate because the
capillary network which constitutes the only preferred channel
towards the outsideIt is interrupted primarily by porosity that is
What do we offer?
As already anticipated, we propose a method of drying completely
different compared to the current which allows to evaporate
selectively the water without altering the integrity of the product
regardless of its thickness and geometric complexity. Furthermore,
the drying time will be reduced by approximately 40% compared to
the current ones, because our mode of drying is targeted only to
water to prevent heating of the ceramic body in a global manner
because the absorption bands are used to focus the heat on the
water . It follows that the power consumption will be below the limit
3200 kJ / kg because we will make less use of air streams dried at
high temperature and low humidity managed by plants with high