Title of Invention	A CONDITION MONITORING SYSTEM FOR MEASURING THE FRICTION VALUE BETWEEN A MOULD AND A SOLIDIFYING SLAB
Abstract	Accordingly, there is provided a condition monitoring system for steel slab caster which adapts multiple sensors for monitoring the friction level, by measuring the friction between the mould and the solidifying slab including monitoring the health of the oscillator for any abnormality in operation. This system adapts at least four numbers of Tri-Axial Accelerometers. Acceleration value is collected in the X, Y and Z direction using the tri-axial accelerometers which are placed at the corners of the continuous casting mould table. The acceleration value is collected for both casting and no casting conditions adapting a data acquisition system. A process module is used to do the post processing of data to calculate the friction and analyze the data collected from the accelerometers for any abnormality in the machine health. The difference between the force during casting and force during no casting with the same frequency of oscillation gives the friction value which appears due to the interaction between mould and the solidifying strand. FFT of the collected data is done in the three directions to find if there is any fault in continuous casting machine that is problem with eccentric cam, worn bearing, non-sinusoidal nature of oscillation.

Title of Invention

A CONDITION MONITORING SYSTEM FOR MEASURING THE FRICTION VALUE BETWEEN A MOULD AND A SOLIDIFYING SLAB

Abstract

Accordingly, there is provided a condition monitoring system for steel slab caster which adapts multiple sensors for monitoring the friction level, by measuring the friction between the mould and the solidifying slab including monitoring the health of the oscillator for any abnormality in operation. This system adapts at least four numbers of Tri-Axial Accelerometers. Acceleration value is collected in the X, Y and Z direction using the tri-axial accelerometers which are placed at the corners of the continuous casting mould table. The acceleration value is collected for both casting and no casting conditions adapting a data acquisition system. A process module is used to do the post processing of data to calculate the friction and analyze the data collected from the accelerometers for any abnormality in the machine health. The difference between the force during casting and force during no casting with the same frequency of oscillation gives the friction value which appears due to the interaction between mould and the solidifying strand. FFT of the collected data is done in the three directions to find if there is any fault in continuous casting machine that is problem with eccentric cam, worn bearing, non-sinusoidal nature of oscillation.

Full Text	FIELD OF INVENTION The present invention relates to measurement of the friction value between the mould and the solidifying slab in a process of continuous casting of steel. More particularly, the present invention relates to a condition monitoring system for monitoring the friction level including the health of the oscillator in a continuous steel casting process. The invention further relates to a method of measuring the friction value between the mold and the solidifying slab in a system during the process of continuous casting of steel. BACKGROUND OF INVENTION Continuous casting is a process whereby molten metal is solidified into a "semifinished product" billet, bloom or slab. Prior to introduction of the continuous casting process, molten steel used to be poured into stationary moulds to form "ingots". However, "continuous casting" process achieves improved yield, quality, productivity and cost efficiency. Presently, continuous casting is the predominant process by which steel is produced in the world. In an integrated steel industry continuous casting of steel plays a great role for the productivity and quality of steel. During continuous casting operation of steel slab, liquid steel is continuously poured in to a tubular mould at one end and at the other end the solidified strand is withdrawn. The mould is continuously 3 cooled to solidify the steel. The mould is oscillated in a sinusoidal motion, so that the liquid steel will not stick to the mould. Due to the interaction between the mould and the steel, friction force between these two arises. Higher friction value leads to poor surface quality and also indicator of abnormalities like sticker during casting process. So it is very important to measure the friction value. In the continuous casting process, illustrated in Figure 1, molten metal is poured from a ladle (1) into a tundish (2) and then through a submerged entry nozzle (3) into a mould cavity (4). The mould (4) is water-cooled so that enough heat is extracted to solidify a shell (5) of sufficient thickness. The shell (5) is withdrawn from the bottom of the mould (4) at a "casting speed" that matches the inflow of metal, so that the process ideally operates at steady state. Below the mould (4), water is sprayed to further extract heat from the strand surface, and the strand (5) eventually becomes fully solid when it reaches the "'metallurgical length"'. Solidification begins in the mould (4), and continues through the different zones (6, 7) of cooling while the strand (5) is continuously withdrawn at the casting speed. Finally, the solidified strand (5) is straightened, cut, and then discharged for intermediate storage or hot charged for finished rolling. To start a cast, the bottom of the mould (4) is sealed by a steel dummy bar (13). This bar (13) prevents liquid metal from flowing out of the mould (4) and the solidifying shell (5) until a fully solidified strand section (5) is obtained. The liquid 4 poured into the mould (4) is partially solidified in the mould (4), producing a strand (5) with a solid outer shell and a liquid core. In this primary cooling area (6), once the steel shell (5) has a sufficient thickness, the partially solidified strand (5) will be withdrawn out of the mould (4) along with the dummy bar (13) at the casting speed. Liquid metal continues to pour into the (4) mould to replenish the withdrawn metal at an equal rate. Upon exiting the mould (4), the strand (5) enters a roller containment section (14) and a secondary cooling chamber (7) in which the solidifying strand (5) is sprayed with water, or a combination of water and air to promote solidification. Once the strand (5) is fully solidified and has passed through the straightener (14), the dummy bar is disconnected, removed and stored. The main function of the mould (4) is to establish a solid shell (5) sufficient in strength to support its liquid core upon entry into the secondary spray cooling zone (7). The mould (4) is basically an open-ended box structure, containing a water-cooled inner lining fabricated from a high purity copper alloy. Mould oscillation is necessary to minimize friction and sticking of the solidifying shell (5), and avoid shell tearing, and liquid steel breakouts, which can wreak havoc on equipment and machine downtime due to clean up and repairs. Friction between the shell (5) and mould (4) is reduced through the use of mould lubricants such as oils or powdered fluxes. Oscillation is achieved either hydraulically or via motor-driven cams or levers which support and reciprocate (or oscillate) the mould. 5 OBJECTS OF INVENTION It is therefore an object of the invention to propose a condition monitoring system for monitoring the friction level including the health of an oscillator in a continuous steel casting process which eliminates the disadvantages of prior art. Another object of the invention is to propose a condition monitoring system for monitoring the friction level including the health of an oscillator in a continuous steel casting process which facilitates production of improved surface quality of the cast steel. A further object of the invention is to propose a method of measuring the friction value between a mould and a solidifying slab including monitoring the machine parameters in a process of continuous casting of steel. SUMMARY OF THE INVENTION Accordingly, there is provided a condition monitoring system for steel slab caster which adapts multiple sensors for monitoring the friction level, by measuring the friction between the mould and the solidifying slab including monitoring the health of the oscillator for any abnormality in operation. This system adapts at least four numbers of Tri-Axial Accelerometers. Acceleration value is collected in the X, Y and Z direction using the tri-axial accelerometers which are placed at 6 the corners of the continuous casting mould table. The acceleration value is collected for both casting and no casting conditions adapting a data acquisition system. A process module is used to do the post processing of data to calculate the friction and analyze the data collected from the accelerometers for any abnormality in the machine health. The difference between the force during casting and force during no casting with the same frequency of oscillation gives the friction value which appears due to the interaction between mould and the solidifying strand. FFT of the collected data is done in the three directions to find if there is any fault in continuous casting machine that is problem with eccentric cam, worn bearing, non- sinusoidal nature of oscillation. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Figure 1 - schematic diagram of a continuous casting process Figure 2 - schematic diagram of the condition monitoring system according to the invention Figure 3 - conceptually shows the principle of an accelerometer in a block diagram Figure 4 - shows a flow chart illustrating the method of the invention. 7 DETAIL DESCRIPTION OF INVENTION A condition monitoring system for steel slab caster is developed adapting multiple sensors for monitoring the friction level, which has an improved effect on slab surface quality. This system can simultaneously measure the friction between the mould (4) and the solidifying slab (5) including monitoring the health of the oscillator (4) for to identify abnormality during the operation. This system adapts four numbers of Tri-Axial Accelerometers (9). Acceleration value is collected in the X, Y and Z direction using the tri-axial accelerometers (9) which are placed at the four corners of the continuous casting mould table (8). The acceleration value is collected for both casting and no casting conditions of the oscillator (4) using a data acquisition device (10). A process module is used for post processing of data in a computer apparatus (11) connected to a power source (12), to calculate the friction value and analyze the data collected from accelerometers (9) for any abnormality in the machine health. The inventive concept leading to the present invention constitutes that a difference between the force during casting and the force during no casting with the same frequency of oscillation gives the friction value which occurs due to the interaction between the mould (4) and the solidifying strand (5). A FFT of the collected data is carried-out in the 3 directions to find out if there is any defect in the continuous casting machine for example problem with eccentric cam, worn of bearing, non-sinusoidal nature of oscillation. 8 The new system is capable to measure the friction between the mould (4) and the solidifying strand (5) efficiently. This will help in evaluating the performance of different kind of lubricants based on the friction value obtained for them during casting. This system also will help in monitoring any abnormal behaviour of the casting machine. As shown in Figure 3, the simplest model of an accelerometer is a mass-spring- damper device (9) that is attached to an enclosing casing (4). The applied acceleration of the casing causes the mass to move, and this motion can be used to determine the magnitude of the acceleration. Due to the movement of the mass the mechanical energy is converted into electrical signal from which the acceleration is calculated. In a tri-axial accelerometer device at least, 3 no of accelerometers are placed in the 3-axis of the space coordinate which can calculate acceleration in 3 directions. The specification of the accelerometers used for this system is given as under: Parameter Min Max Units Range -2 +2 g Operating Temp Range -40 +85 °c Bandwidth 10 kHz 9 Figure 4 describes the steps carried out by the process module embedded in the computer apparatus (11). Step 1: Acceleration data is read from the accelerometer (9) online Casting speed data is read from operating table online Matching the casting speed with the cold force data is read from COLD FORCE (the force exerted with empty mould) look up table Step 2: Oscillation frequency is calculated from the casting speed by multiplying a constant A Step 3: Fast Fourier Transformation (FFT) analysis of the acceleration data is done and the Amplitude vs frequency plot is displayed Step 4: Angular velocity (GO) is calculated from the frequency of oscillation as Angular Velocity (ω) = 2nf Step 5: Displacement (d) of the mould table (8) is calculated as Displacement (d) = -a/ω2 10 The displacement of mould with time is displayed Step 6: HOT FORCE or the force on caster during casting is calculated by taking the Root Mean Square (RMS) value of the acceleration. Step 7: The friction value is calculated for the current casting speed by subtracting the COLD FORCE from HOT FORCE and the friction with time is displayed. ADVANTAGES OF THE INVENTION: 1. On-line monitoring of mould oscillation is an important tool for the performance of casting and also improving machine reliability. 2. Various parameters can be optimized using this system to lower the friction level during casting. 3. Any abnormality situation like break-out can be known prior to its happening by monitoring the friction level. 4. The friction force for different kind of lubricant can be assessed and the best lubricant can be evaluated by this system. 5. This equipment is very useful as a preventive maintenance tool by providing early warning about problems related to health of the machine. 11 We Claim 1. A condition monitoring system for steel slab caster for measuring the friction value between a mould and a solidifying slab including monitoring the health of the oscillator in a process of continuous casting of steel, the system comprising: - a plurality of accelerometer (9) disposed at different corners of a continuous casting mould table (8) to capture acceleration data, the mould table (8) being operably connected to a data acquisition device (10), the mould (4) being caused to oscillate in a sinusoidal motion via an electrically operated rotating means leading to generation of mechanical energy due to movement of liquid or solidifying steel between the mould (4), the accelerations values in X, Y and Z directions in the form of converted electric signals being outputted by the data acquisition device (10) both at casting and no-casting conditions; - a process module incorporated in a computer apparatus (11) for calculating the friction value generating due to interaction between the mould (4) and the solidifying strand (5), and for analyzing the collected data by adapting a Fast Fourier Transformation algorithm to identify any abnormality in the machine parameters. 12 2. A method of measuring the friction value between a mould and a solidifying slab including monitoring the machine parameters in a process of continuous casting of steel, comprising the steps of: - providing a condition monitoring system as claimed in claim 1 being operably disposed on a mould table of the casting machine; - online reading of acceleration data and casting speed data respectively from the accelerometers and the mould table (8); - matching the casting speed in correspondence with the cold force value displayed on the look-up table (8); - calculating oscillation frequency from the acquired casting speed data by multiplying a constant A; - generating a graphical display of amplitude vs frequency data by applying First Fourier Transformation algorithm; - calculating the angular velocity (ω) in the form of ω = 2nf from the frequency of oscillation; - calculating displacement of the mould table (8) in the form of (d) = -a /ω2 13 - determining hot force on caster during casting by calculating Root Mean Square (RMS) value of the acceleration data; and - calculating the friction value by subtracting the cold force value from the hot force value. 3. A condition monitoring system for steel slab caster for measuring the friction value between a mould and a solidifying slab including monitoring the health of the oscillation in a process of continuous casting of steel as substantially described herein with reference to the accompanying drawings. 4. A method of measuring the friction value between a mould and a solidifying slab including monitoring the machine parameters; in a process of continuous casting of steel as substantially described herein with reference to the accompanying drawings. Dated this 11th day of APRIL 2007 Accordingly, there is provided a condition monitoring system for steel slab caster which adapts multiple sensors for monitoring the friction level, by measuring the friction between the mould and the solidifying slab including monitoring the health of the oscillator for any abnormality in operation. This system adapts at least four numbers of Tri-Axial Accelerometers. Acceleration value is collected in the X, Y and Z direction using the tri-axial accelerometers which are placed at the corners of the continuous casting mould table. The acceleration value is collected for both casting and no casting conditions adapting a data acquisition system. A process module is used to do the post processing of data to calculate the friction and analyze the data collected from the accelerometers for any abnormality in the machine health. The difference between the force during casting and force during no casting with the same frequency of oscillation gives the friction value which appears due to the interaction between mould and the solidifying strand. FFT of the collected data is done in the three directions to find if there is any fault in continuous casting machine that is problem with eccentric cam, worn bearing, non-sinusoidal nature of oscillation.

Full Text

FIELD OF INVENTION
The present invention relates to measurement of the friction value between the
mould and the solidifying slab in a process of continuous casting of steel. More
particularly, the present invention relates to a condition monitoring system for
monitoring the friction level including the health of the oscillator in a continuous
steel casting process. The invention further relates to a method of measuring the
friction value between the mold and the solidifying slab in a system during the
process of continuous casting of steel.
BACKGROUND OF INVENTION
Continuous casting is a process whereby molten metal is solidified into a
"semifinished product" billet, bloom or slab. Prior to introduction of the
continuous casting process, molten steel used to be poured into stationary
moulds to form "ingots". However, "continuous casting" process achieves
improved yield, quality, productivity and cost efficiency. Presently, continuous
casting is the predominant process by which steel is produced in the world.
In an integrated steel industry continuous casting of steel plays a great role for
the productivity and quality of steel. During continuous casting operation of steel
slab, liquid steel is continuously poured in to a tubular mould at one end and at
the other end the solidified strand is withdrawn. The mould is continuously

3
cooled to solidify the steel. The mould is oscillated in a sinusoidal motion, so that
the liquid steel will not stick to the mould. Due to the interaction between the
mould and the steel, friction force between these two arises. Higher friction
value leads to poor surface quality and also indicator of abnormalities like sticker
during casting process. So it is very important to measure the friction value.
In the continuous casting process, illustrated in Figure 1, molten metal is poured
from a ladle (1) into a tundish (2) and then through a submerged entry nozzle
(3) into a mould cavity (4). The mould (4) is water-cooled so that enough heat is
extracted to solidify a shell (5) of sufficient thickness. The shell (5) is withdrawn
from the bottom of the mould (4) at a "casting speed" that matches the inflow of
metal, so that the process ideally operates at steady state. Below the mould (4),
water is sprayed to further extract heat from the strand surface, and the strand
(5) eventually becomes fully solid when it reaches the "'metallurgical length"'.
Solidification begins in the mould (4), and continues through the different zones
(6, 7) of cooling while the strand (5) is continuously withdrawn at the casting
speed. Finally, the solidified strand (5) is straightened, cut, and then discharged
for intermediate storage or hot charged for finished rolling.
To start a cast, the bottom of the mould (4) is sealed by a steel dummy bar (13).
This bar (13) prevents liquid metal from flowing out of the mould (4) and the
solidifying shell (5) until a fully solidified strand section (5) is obtained. The liquid

4
poured into the mould (4) is partially solidified in the mould (4), producing a
strand (5) with a solid outer shell and a liquid core. In this primary cooling area
(6), once the steel shell (5) has a sufficient thickness, the partially solidified
strand (5) will be withdrawn out of the mould (4) along with the dummy bar (13)
at the casting speed. Liquid metal continues to pour into the (4) mould to
replenish the withdrawn metal at an equal rate. Upon exiting the mould (4), the
strand (5) enters a roller containment section (14) and a secondary cooling
chamber (7) in which the solidifying strand (5) is sprayed with water, or a
combination of water and air to promote solidification. Once the strand (5) is
fully solidified and has passed through the straightener (14), the dummy bar is
disconnected, removed and stored.
The main function of the mould (4) is to establish a solid shell (5) sufficient in
strength to support its liquid core upon entry into the secondary spray cooling
zone (7). The mould (4) is basically an open-ended box structure, containing a
water-cooled inner lining fabricated from a high purity copper alloy. Mould
oscillation is necessary to minimize friction and sticking of the solidifying shell
(5), and avoid shell tearing, and liquid steel breakouts, which can wreak havoc
on equipment and machine downtime due to clean up and repairs. Friction
between the shell (5) and mould (4) is reduced through the use of mould
lubricants such as oils or powdered fluxes. Oscillation is achieved either
hydraulically or via motor-driven cams or levers which support and reciprocate
(or oscillate) the mould.

5
OBJECTS OF INVENTION
It is therefore an object of the invention to propose a condition monitoring
system for monitoring the friction level including the health of an oscillator in a
continuous steel casting process which eliminates the disadvantages of prior art.
Another object of the invention is to propose a condition monitoring system for
monitoring the friction level including the health of an oscillator in a continuous
steel casting process which facilitates production of improved surface quality of
the cast steel.
A further object of the invention is to propose a method of measuring the friction
value between a mould and a solidifying slab including monitoring the machine
parameters in a process of continuous casting of steel.
SUMMARY OF THE INVENTION
Accordingly, there is provided a condition monitoring system for steel slab caster
which adapts multiple sensors for monitoring the friction level, by measuring the
friction between the mould and the solidifying slab including monitoring the
health of the oscillator for any abnormality in operation. This system adapts at
least four numbers of Tri-Axial Accelerometers. Acceleration value is collected in
the X, Y and Z direction using the tri-axial accelerometers which are placed at

6
the corners of the continuous casting mould table. The acceleration value is
collected for both casting and no casting conditions adapting a data acquisition
system. A process module is used to do the post processing of data to calculate
the friction and analyze the data collected from the accelerometers for any
abnormality in the machine health.
The difference between the force during casting and force during no casting with
the same frequency of oscillation gives the friction value which appears due to
the interaction between mould and the solidifying strand. FFT of the collected
data is done in the three directions to find if there is any fault in continuous
casting machine that is problem with eccentric cam, worn bearing, non-
sinusoidal nature of oscillation.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 - schematic diagram of a continuous casting process
Figure 2 - schematic diagram of the condition monitoring system according to
the invention
Figure 3 - conceptually shows the principle of an accelerometer in a block
diagram
Figure 4 - shows a flow chart illustrating the method of the invention.

7
DETAIL DESCRIPTION OF INVENTION
A condition monitoring system for steel slab caster is developed adapting
multiple sensors for monitoring the friction level, which has an improved effect
on slab surface quality. This system can simultaneously measure the friction
between the mould (4) and the solidifying slab (5) including monitoring the
health of the oscillator (4) for to identify abnormality during the operation. This
system adapts four numbers of Tri-Axial Accelerometers (9). Acceleration value is
collected in the X, Y and Z direction using the tri-axial accelerometers (9) which
are placed at the four corners of the continuous casting mould table (8). The
acceleration value is collected for both casting and no casting conditions of the
oscillator (4) using a data acquisition device (10). A process module is used for
post processing of data in a computer apparatus (11) connected to a power
source (12), to calculate the friction value and analyze the data collected from
accelerometers (9) for any abnormality in the machine health.
The inventive concept leading to the present invention constitutes that a
difference between the force during casting and the force during no casting with
the same frequency of oscillation gives the friction value which occurs due to the
interaction between the mould (4) and the solidifying strand (5). A FFT of the
collected data is carried-out in the 3 directions to find out if there is any defect in
the continuous casting machine for example problem with eccentric cam, worn of
bearing, non-sinusoidal nature of oscillation.

8
The new system is capable to measure the friction between the mould (4) and
the solidifying strand (5) efficiently. This will help in evaluating the performance
of different kind of lubricants based on the friction value obtained for them
during casting. This system also will help in monitoring any abnormal behaviour
of the casting machine.
As shown in Figure 3, the simplest model of an accelerometer is a mass-spring-
damper device (9) that is attached to an enclosing casing (4). The applied
acceleration of the casing causes the mass to move, and this motion can be used
to determine the magnitude of the acceleration. Due to the movement of the
mass the mechanical energy is converted into electrical signal from which the
acceleration is calculated. In a tri-axial accelerometer device at least, 3 no of
accelerometers are placed in the 3-axis of the space coordinate which can
calculate acceleration in 3 directions.
The specification of the accelerometers used for this system is given as under:

Parameter Min Max Units
Range -2 +2 g
Operating Temp Range -40 +85 °c
Bandwidth 10 kHz

9
Figure 4 describes the steps carried out by the process module embedded in the
computer apparatus (11).
Step 1: Acceleration data is read from the accelerometer (9) online
Casting speed data is read from operating table online
Matching the casting speed with the cold force data is read from COLD FORCE
(the force exerted with empty mould) look up table
Step 2: Oscillation frequency is calculated from the casting speed by multiplying
a constant A
Step 3: Fast Fourier Transformation (FFT) analysis of the acceleration data is
done and the Amplitude vs frequency plot is displayed
Step 4: Angular velocity (GO) is calculated from the frequency of oscillation as
Angular Velocity (ω) = 2nf
Step 5: Displacement (d) of the mould table (8) is calculated as
Displacement (d) = -a/ω2

10
The displacement of mould with time is displayed
Step 6: HOT FORCE or the force on caster during casting is calculated by taking
the Root Mean Square (RMS) value of the acceleration.
Step 7: The friction value is calculated for the current casting speed by
subtracting the COLD FORCE from HOT FORCE and the friction with time is
displayed.
ADVANTAGES OF THE INVENTION:
1. On-line monitoring of mould oscillation is an important tool for the
performance of casting and also improving machine reliability.
2. Various parameters can be optimized using this system to lower the
friction level during casting.
3. Any abnormality situation like break-out can be known prior to its
happening by monitoring the friction level.
4. The friction force for different kind of lubricant can be assessed and the
best lubricant can be evaluated by this system.
5. This equipment is very useful as a preventive maintenance tool by
providing early warning about problems related to health of the machine.

11
We Claim
1. A condition monitoring system for steel slab caster for measuring the
friction value between a mould and a solidifying slab including monitoring
the health of the oscillator in a process of continuous casting of steel, the
system comprising:
- a plurality of accelerometer (9) disposed at different corners of a
continuous casting mould table (8) to capture acceleration data,
the mould table (8) being operably connected to a data acquisition
device (10), the mould (4) being caused to oscillate in a sinusoidal
motion via an electrically operated rotating means leading to
generation of mechanical energy due to movement of liquid or
solidifying steel between the mould (4), the accelerations values in
X, Y and Z directions in the form of converted electric signals being
outputted by the data acquisition device (10) both at casting and
no-casting conditions;
- a process module incorporated in a computer apparatus (11) for
calculating the friction value generating due to interaction between
the mould (4) and the solidifying strand (5), and for analyzing the
collected data by adapting a Fast Fourier Transformation algorithm
to identify any abnormality in the machine parameters.

12
2. A method of measuring the friction value between a mould and a
solidifying slab including monitoring the machine parameters in a process
of continuous casting of steel, comprising the steps of:
- providing a condition monitoring system as claimed in claim 1 being
operably disposed on a mould table of the casting machine;
- online reading of acceleration data and casting speed data
respectively from the accelerometers and the mould table (8);
- matching the casting speed in correspondence with the cold force
value displayed on the look-up table (8);
- calculating oscillation frequency from the acquired casting speed
data by multiplying a constant A;
- generating a graphical display of amplitude vs frequency data by
applying First Fourier Transformation algorithm;
- calculating the angular velocity (ω) in the form of ω = 2nf from the
frequency of oscillation;
- calculating displacement of the mould table (8) in the form of (d) =
-a /ω2

13
- determining hot force on caster during casting by calculating Root
Mean Square (RMS) value of the acceleration data; and
- calculating the friction value by subtracting the cold force value
from the hot force value.

3. A condition monitoring system for steel slab caster for measuring the
friction value between a mould and a solidifying slab including monitoring
the health of the oscillation in a process of continuous casting of steel as
substantially described herein with reference to the accompanying
drawings.
4. A method of measuring the friction value between a mould and a
solidifying slab including monitoring the machine parameters; in a process
of continuous casting of steel as substantially described herein with
reference to the accompanying drawings.
Dated this 11th day of APRIL 2007

Accordingly, there is provided a condition monitoring system for steel slab caster which adapts multiple sensors for monitoring the friction level, by measuring the friction between the mould and the solidifying slab including monitoring the health of the oscillator for any abnormality in operation. This system adapts at least four numbers of Tri-Axial Accelerometers. Acceleration value is collected in the X, Y and Z direction using the tri-axial accelerometers which are placed at
the corners of the continuous casting mould table. The acceleration value is collected for both casting and no casting conditions adapting a data acquisition system. A process module is used to do the post processing of data to calculate the friction and analyze the data collected from the accelerometers for any abnormality in the machine health.
The difference between the force during casting and force during no casting with the same frequency of oscillation gives the friction value which appears due to the interaction between mould and the solidifying strand. FFT of the collected data is done in the three directions to find if there is any fault in continuous casting machine that is problem with eccentric cam, worn bearing, non-sinusoidal nature of oscillation.

Documents:

00570-kol-2007-claims.pdf

00570-kol-2007-correspondence others 1.1.pdf

00570-kol-2007-correspondence others 1.2.pdf

00570-kol-2007-correspondence others.pdf

00570-kol-2007-description complete.pdf

00570-kol-2007-drawings.pdf

00570-kol-2007-form 1 1.1.pdf

00570-kol-2007-form 1.pdf

00570-kol-2007-form 18.pdf

00570-kol-2007-form 2.pdf

00570-kol-2007-form 3.pdf

00570-kol-2007-gpa.pdf

570-KOL-2007-(03-05-2012)-CORRESPONDENCE.pdf

570-KOL-2007-(03-05-2012)-OTHERS.pdf

570-KOL-2007-(29-12-2011)-ABSTRACT.pdf

570-KOL-2007-(29-12-2011)-AMANDED CLAIMS.pdf

570-KOL-2007-(29-12-2011)-CORRESPONDENCE.pdf

570-KOL-2007-(29-12-2011)-DESCRIPTION (COMPLETE).pdf

570-KOL-2007-(29-12-2011)-DRAWINGS.pdf

570-KOL-2007-(29-12-2011)-FORM-1.pdf

570-KOL-2007-(29-12-2011)-FORM-2.pdf

570-KOL-2007-(29-12-2011)-OTHERS.pdf

570-KOL-2007-CORRESPONDENCE 1.1.pdf

570-KOL-2007-CORRESPONDENCE 1.2.pdf

570-KOL-2007-EXAMINATION REPORT.pdf

570-KOL-2007-FORM 18.pdf

570-KOL-2007-FORM 3.pdf

570-KOL-2007-GPA.pdf

570-KOL-2007-GRANTED-ABSTRACT.pdf

570-KOL-2007-GRANTED-CLAIMS.pdf

570-KOL-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

570-KOL-2007-GRANTED-DRAWINGS.pdf

570-KOL-2007-GRANTED-FORM 1.pdf

570-KOL-2007-GRANTED-FORM 2.pdf

570-KOL-2007-GRANTED-LETTER PATENT.pdf

570-KOL-2007-GRANTED-SPECIFICATION.pdf

570-KOL-2007-OTHERS.pdf

570-KOL-2007-REPLY TO EXAMINATION REPORT.pdf

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Patent Number

253846

Indian Patent Application Number

570/KOL/2007

PG Journal Number

35/2012

Publication Date

31-Aug-2012

Grant Date

29-Aug-2012

Date of Filing

11-Apr-2007

Name of Patentee

TATA STEEL LIMITED

Applicant Address

JAMSHEDPUR

Inventors:

#	Inventor's Name	Inventor's Address
1	PREETI PRAKASH SAHOO	R&D, TATA STEEL LIMITED, JAMSHEDPUR 831001

PCT International Classification Number

B22D11/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA