cs003ben_20_coloral
TRANSCRIPT
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Neutralization at Coloral
Complete industrial wastewater treatment plant for acidic
and alkaline wastewater arising from production
Coloral, a company with headquartersin Neuchtel, processes customer or-ders in the area of surface treatments.These include mechanical processes,such as sandblasting, brushing,engraving, CNC lasering, polishing,drilling and milling, among others.Electromechanical processes, such aschemical chromatization, chemicalengraving, decorative anoxic oxida-
tion and other chemical processes,produce different types of acidic andalkal ine wastewater.
These must be treated before theyare discharged into the public sewagetreatment plant.
For the new CP system, the customerassigned Endress+Hauser with thedesign of a complete wastewater treat-ment i.e. neutralizat ion facility.
Concept
With CP (cathodic protection), a new
surface treatment machine, Coloral is
expanding to an industrial facility in La
Neuveville.
Even during the planning stage of this ex-
pansion, the wastewater treatment concept
received particular attention.
Ordinary sur face treatment in the CP
machine involves surface treatment of
semi-finished products made of aluminum,
using alka li and acid. During the process,small amounts of acidic and alkaline
wastewater are produced. These are
subject to continuous neutralization before
entering the sewage system.
Once or twice a month, the acidic and
alkal ine baths in the CP machine must be
replaced. The only way to treat the heavily
contaminated wastewater is by means of
batch neutralization.
Due to space restrictions, a combination of
both processes presented the only viable
option.
Chemical dosing station and pH measurement Reservoir Display on touch panel
Scopeof
delivery
Endress
+Hauser
-Bas
icengine
ering
-Det
ailengin
eering
-CA
Dwiring
scheme
-Ca
binet
-Soft
ware
-PLC
program
mablelo
gic
controlle
r
-Me
asureme
nttechn
ology
-Bas
in,agita
tor,valv
es,
pumps
-Mo
unting
-Com
missioni
ng
Fact
s
-Lowsp
acerequ
irements
-Aut
omaticc
ontrolle
r
-Tur
n-keysy
stem
-Com
bination
of
continuo
usandb
atch
neutraliz
ation
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Instruments International
Endress+Hauser
Instruments International AG
Kaegenstrasse 2
4153 Reinach
Switzerland
Tel. +41 61 715 81 00
Fax +41 61 715 25 00
http://www.endress.com
12.06/I.I.
CS 003B/20/en/12.07
EH/INDD CS2
Planning, construction
The key to success in this project was
engineering and project management.
The customer wanted a turn-key system
including the process for wastewater treat-
ment.
The low space requirement, together with
a combination of continuous and batch
neutralization, presented a real challenge
in the planning and construction of the
system. A PLC system, type WAGO I/O,
was used to build the cabinet.
A touch panel was used to provide a qu ick
and simple overview of the current opera-
tion. The interactive display, showing the
status of the basins, pumps, valves and lev-
els, keeps you informed about the process
sequence at all times.
Using a rotary switch, the customer can
switch between continuous and batch neu-
tralization. This is of particular importance
as the basin must first be completely emp-
tied for batch neutralization. This is due
to the fact that during clean ing of the CP
machine, several hundred liters of diluted
alka li and acid are produced. As these have
different concentrations, space is needed
initially in the neutralization basin after
mixing to allow for the larger quantity of
chemicals which must be added.
When the plant was commissioned, itemerged that, due to the precision control
of the PLC, chemical pumps with large
dosing units are also suitable for dosing
small amounts during normal operation.
Continuous and batch basin
View of the neutra lizat ion basin
The PLC is then able to call on the maxi-
mum dosing performance of the pumps
duning batch neutralization.
In the outlet of the system, the pH value is
measured and continuously recorded using
a graphic display recorder.