A European group of companies - Saria Bio-Industries AG & Co. KG

Entrance to the Przewrotne
site, Poland’s most advanced
facility for processing
animal by-products
Sludge drying in Przewrotne
Environmentally friendly utilisation of heat
In the process of treating sewage both at municipal and industrial treatment
plants, a large amount of surplus activated sludge is generated. Processing this
sludge can significantly affect the functioning and performance of sewage
plants and this was also the situation in Poland until now.
well as making it possible to obtain
fuel from the dried sludge mass.
Compared to the previous cost of
disposing of sludge outside the plant,
Czesław Malita,
Plant Manager
Przewrotne branch
When modernising the facility as a
whole and increasing production
capacity, the excessive condensate
temperature became a problem. In
terms of thermal balance, this does
not seem to be a major issue, because
the water is redeployed in operations.
However, at temperatures above
100°C damage occurs to the pump
walls. Not only does this increase
wear and tear to pumps – worse still,
it completely stops the production of
steam.
Given these two problems, managing
director Franciszek Pątko came up
with the idea to build a drying facility
that would use the heat from the condensates
returning from the production
plants as a source of energy.
The drying facility covers an area of
180 sq m, with the flooring in the
heated section made of concrete into
which heating tubes are integrated.
In order to accelerate the drying
process, five mechanical heaters were
also incorporated, whose outlets are
directed at the drying layer.
The heat source for both the floor
heating and the heaters is the energy
contained in the returning condensate.
Drying the layer takes a good
48 hours. The dried sludge can then
be incinerated with small coal, with
the dried mass generating 17,000
kcal/kg. Applying this method lowers
the temperature of the condensate
and reduces the pumps’ vulnerability
to breakdown in the boiler plant, as
Gołcza
Przewrotne
Bereza
which cost up to 200 euros per
tonne, this measure has reduced production
costs by a significant
amount.
● Czesław Malita
Przewrotne,
Poland
La Coruna – Benet – Rezé – Issé – Vitré – Concarneau – Plouvara – Hüttenfeld – Würzburg – Eltmann Limbach – Elxleben – Marl
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