State of the art technology: Continuous casting solutions for oil and grease caused troubles in cooling water systems

NEWSLETTER | Volume 01 | January 20
12





State of the art technology:

Continuous casting

solutions for oil and grease

caused troubles in cooling water systems



Kurita Europe GmbH
•
††


Industriering 43

•
†


41751 Viersen
•



Germany
•
†


Phone +49 2162 95
80110
•
†

E
-
Mail:


inf
o@
kurita.de






Fax

+49 2162 40159

•


Internet: ww
w
.
kurita.de



The challenge


Since the 1960s continuous casting became
more and more important in modern steel
production. More than 80% of the worldwide
production and more than 95% of the
German steel fabrication use this process.


The need of optimizing and maximiz
ing every
important parameter of the manufacturing
process leads
us
to
the consideration of the
secondary cooling.

Improvement of this part
of the facility provides

for

more safety, less
maintenance and
other measurable savings
.


There are two main
cause
s for scaling and
clogging issues
in cooling water systems
of
continuous casting plants
:

calcium fluoride
and oil and grease which get into the system
through lubrication. The mechanisms of
malfunction caused by oil and grease
usually
are:




o
il and grease
are

left inside the cooling
tower

→

cooling capacity and efficiency
are




decreased

→

water temperature becomes higher




c
oncentration of oil and grease in cooling
water


→


sticking to strainers, spray nozzles and

water pipes

→


r
isk of decreasing flow rates, spr
ay

water amount, cool
ing effect






o
il and grease stick to filter media

→

d
e
crease of

filter
capacity and efficiency




o
il leakage from backwash water systems

→

oil and grease return back into the cooling


system and concentrate

→

stick to surrounding equipment


A proper op
erating cooling water system and the
avoidance of production failure require a careful
water treatment with the best
available
technique.



The solution


Depending on the specific requirements of a
cooling water system in the continuous caster
plant, there

are several possible approaches to
reach the goals.

Kurita developed an array of
special products which generate highest
prosperity.



fig 1.:
possible
spots of applications



1)

Against oil stain at the cooling tower: dosage of
Kurita Polyclean into the re
turn water at the top
of the cooling tower with 6
-
8 ppm

NEWSLETTER | Volume 01 | January 2012




State of the art technology:
Continuous casting solutions for oil and grease
caused troubles in cooling water systems


Kurita Europe GmbH
•



Industriering 43

•



41751 Viersen
•



Germany
•



Phone +49 2162 95
80110
•


E
-
Mail:


inf
o@
kurita.de






Fax

+49 2162 40159

•


Internet: ww
w
.
kurita.de



2) In case of clogging of strainers, spray
nozzles and water pipes: 40-60 ppm
Coagulant is recommended to be dosed at
the scale pit

3) Filter cleaning: 50-100 ppm Kurita Diclean
has to be added to the backwash water of
the sand filters in order to keep filters
clean and efficient. Dosing point: Pipeline
of the backwash water

4) Oil leakages from backwash water
treatment: use of an organic coagulant,
which is to be added 1-3 ppm to the back
wash waste water



fig. 2: study of water pipe before and after treatment





fig. 3: study of sand filter material during treatment




Conditions:

i
nlet
water

o
utlet
water
before
treatment

o
utlet
water
after
treatment

pH [
-
]

8
.
5

8
.
2

7
.
6

s
uspendend
solids [mg/l]

15

<1
0

<10

t
urbidity [ntu]

1
.
9

1
.
4

1
.
3

o
il and
grease [mg/l]

3
.
3

3
.
1

<1


The result

The optimal treatment for a specific continuous
caster plant depends on many different factors.
The consideration of the entire system is
necessary to develop the optimal concept.

As oil and grease can lead to several huge
problems in the cooling water system they need to
be avoided in the distribution system, in the
cooling tower and in the sand filters. The variety of
Kurita proprietary advanced cooling water products
provides the ideal basis for the optimal treatment.

The application of the Kurita scaling inhibitor and
filter conditioner improved the steel plant
performance significantly. The sand filters worked
more efficient, the backwash frequency decreased
and the water quality improved. The amount of
biocide demand was reduced about 20 % and the
number of failures was reduced remarkably.