Measuring where it really matters - Michenfelder

draft report for trade press publication in the magazine GIESSEREI ERFAHRUNGSAUSTAUSCH 11/2008
FoMaSys
Module 1
Module 2
Module 3 Moisture Control
Systems for
Mixers
Moisture Control
Systems for
Coolers
Online Sand Testing System VEDIMAT
Material taking from con-
veyor belt by elevating unit
test of compactability
charging of test cylinder
test of compressive strength
Fig_3:
By controlling compactability at the moulding line directly, any
subtle changes are detected and compensated for through
feedback to the moisture control system. That means
compactability is automatically kept very constant.
The idea behind FoMaSys
The idea behind FoMaSys is to create
a network of intelligent measurement,
control and testing systems, while at
the same time trying to combat the
effects of dehomogenisation and
change by the application of process
technology. Looking at additives and
superfines, the motto is: What comes
out should be the same as what goes
in – i.e. it should be as consistent as
possible concerning times and
quantities. Measurement and control
technology ensures that first of all, the
sand is accurately pre-wetted (to at
least 2%) in the used sand bunker, and
secondly, that it reaches the moulding
line with consistently optimal
mechanical properties (flowable).This
ensures the reliability of the tried and
trusted moisture measuring and control
systems that are networked and
monitored centrally. The high level of
automation also produces
rationalisation effects. Precision and
reliability reduce scrap, and continuous
control ensures a sand conditioning
process that is cost-effective and that
consistently conserves resources.
Constant compactability where it
really matters – directly at the
moulding line
As a relevant factor for sand quality,
online control of compactability is
essential. Automatically controlling
compactability through the addition of
water during production has become
an established trend. In order to obtain
Module 4
Process Control
System MiPro
installation example
Moisture Control
Systems for
Mixers
or expand the relevant expertise,
competitors have now responded by
entering into joint ventures and
acquisitions. In the case of some
manufacturers, this expertise has
been developed in-house over several
years – one-stop system solutions, as
demonstrated so convincingly by the
FoMaSys are a matter of course.
More and more imitators are coming
to the realisation that continuous
measurement in the mixing equipment
(i.e. in the mixer or cooler) is essential
for a precise sand moisture control. In
relation to this major issue, FoMaSys
manufacturer Michenfelder can rely on
a head start of 40 years of knowledge.
Success factors
1.) The sand moisture is kept
constant within a tight tolerance
of 2% at the cooler outlet.
2.) The incomparable precision of
moisture measurement and mois-
ture control achieved thanks to
the accurate in-mixer and incooler
measurement technology
(incl. the patented mixing
dynamics monitoring system)
3.) The special installation location of
the online sand testing system
VEDIMAT on the conveyor belt
directly before the moulding machine.
Module 1
Module 2
Module 3
Moisture Control
Systems for
Coolers
FoMaSys
Module 4
Process Control
and Quality Assurance System MiPro
Total plant view
Materialaufnahme vom
Förderband per Aufzug
On-line Sand
Testing System
VEDIMAT
Process data analysis, evaluation
Einbaubeispiel
and archiving
Monitoring of single modules remote control in 1-to-1-view
Fig_4:
With MiPro moulding sand quality control comes into your office.
Analyse the trends and evaluate production data – online or from
archived database. Make relationships and developments in the
sand cycle transparent comprehensible in an easy way.
By combining FoMaSys modules 1 and
3, it is possible to reliably record and
compensate for any negative factors
influencing the moulding sand on its
way from the mixer to the moulding
machine that could have a long-term
detrimental impact on compactability
(e.g. different bentonite saturation
levels due to unstable initial moisture
in the mixer, or moisture changes due
to differences in temperature, and
evaporation or mechanical changes
caused by aeration or material transfer
stations). None of these influences are
identified or taken into account when
compactability is measured in the
mixer. Variations of ±0.1% in moisture
levels in the mixer result in
compactability fluctuations of up to ±2-
3% in the moulding machine. There
are some foundries where fluctuations
of up to 10-12% in compactability
between the mixer and the moulding
machine have been shown to occur –
particularly when there is no sand
cooler at all or where there is a sand
cooler in which sand moisture is poorly
regulated.
From a well-nursed prejudice to
technological head start
However, there is one preconception
that needs to be eliminated: contrary to
what many people believe or claim to
be the case, measuring compactability
just before the moulding machine is by
no means too late. Since it is well
known that there is a correlation
between moisture and compactability,