Title of Invention

AN APPARATUS FOR MEASURING IN REAL TIME THE MASS FLOW RATE OF SLAG TAPPED FROM A BLAST FURNACE

Abstract This invention relates to an apparatuses for real-time measurement of mass flow rate of slag tapped from blast furnace. More specially, the invention relates to real time measurement within a precision , flow rate molten slag discharged from a blast furnace.
Full Text FIELD OF INVENTION
This invention relates to an apparatus for measuring in real time the mass flow
rate of slag tapped from a blast furnace.
BACKGROUND OF THE INVENTION
Blast furnace slag is a nonmetallic byproduct of the iron and steel making
process. The process starts with the extraction of iron from iron ore. In the
production of iron, iron ore, fluxes (limestone and / or dolomite) are charged into
a blast furnace along with coke as fuel to separate molten iron from other
materials. These impurities consisting of silicon and alumina combine with
calcium and magnesium to form molten slag.
When the blast furnace is tapped to release the molten iron, it flows from the
furnace with the molten slag floating on its upper surface. These two materials
are separated using a weir, the molten iron channeled to a holding vessel
(torpedo ladle) and the molten slag to a water crash facility where jet water of a
constant pressure is applied to it.
Quenching molten slag with large volumes of water produces granulated blast
furnace slag. The blast furnace slag is instantaneously brought to a temperature
below the boiling point of water, converting it to fine sand-sized particles in an
amorphous glassy form.

The slag and water slurry after quenching flows through a conduit to the slag pit
where the slag Is de-watered. An ejection conveyer empties wet granulated slag
from the pit at a regular interval. A load cell placed in the ejection conveyer
system gives weight of the slag tapped from the furnace.
Belt scale output thus obtained suffers from significant time lag and is on a
higher side because of the moisture content of the slag. Moreover, this does not
provide instantaneous values in real time and is hence of no use to furnace
operations supervision and control. So, it is required to have a system that
provides accurate values of slag flow rate in real time with minor lag.
An example of a slag flow rate measurement system is disclosed in document
JP11037819. It provides an image processing based system that measures the
slag flow sectional area, calculated from the width of the slag flowing in a V-
shaped conduit. Sectional area of slag flow and slag flow speed based on
inclination angle of conduit and slag viscosity acquired from the measured slag
temperature gives the slag flow rate.
Document JP58144715, uses an ultrasonic wave current meter to measure the
flow speed of the slag from the blast furnace. Measured signal from the above
sensor and a level meter to measure the level of slag in blast furnace are used to
compute the slag flow rate.
In both the examples, however, the system is placed before the water crash
facility and is based on altogether different principles. Slag flow measurement
system has a complicated structure and is exposed to wear of runner, which may
reduce the accuracy of the system.

SUMMARY OF THE INVENTION
The main object of this invention is to provide a real time slag flow rate
measurement system that is capable of giving the slag flow rate with minimum
time lag and a high precision.
Another object of this invention is to provide a slag flow rate measurement
system that has a simplified structure.
These and other objects of the present invention are achieved by measuring the
flow rate of slag tapped from blast furnace with reference to a signal produced
from an infrared pyrometer located just above the slurry conduit in the slag
granulation facilities. Another thermocouple in the inlet water pipe measures the
inlet water temperature and change in slurry/water temperature after slag
granulation is obtained in real time with minor lag.
The temperature difference described above is multiplied by slag flow rate (SFR)
constant to provide the slag flow rate. Evaluation of an exact value of SFR
constant is not possible as such a value does not exist. Hence two different
methods that calculate its bounds have been formulated. One approaches the
value of the constant from the lower side (below) and the other from above so
that the value of the constant lies between these two bounds and this represents
the degree of precision / domain of error in the value.

A feedback control using slag flow rate as a parameter is used to control the
amount of water required in granulation process. This apart from helping to
improve the overall efficiency of the granulation process, reduces the risk of
water vapour explosion.
More importantly, the availability of measured values of slag flow rate in real
time allow the development of furnace models that facilitate supervision and
control of furnace operations.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 shows a configuration of blast furnace slag granulation setup that
employs the molten slag flow rate measurement device of the present invention.
Figure 2 shows a configuration of molten slag flow rate measurement system of
the present invention.
Figure 3a shows a graph for typical slag flow cycle with slag flow rate plotted
against time.
Figure 3b shows the MMI depicting the slag flow rate in the blast furnace control
room.
Rgure 4a shows the front view of the IR pyrometer used for slag flow rate
measurement.
Figure 4b shows the side view of the slag flow rate measurement setup with IR
pyrometer placed obliquely over the slag slurry channel.

DESCRIPTION OF PREFERRED EMBODIMENT
An embodiment of the present invention will now be described with reference to
the accompanying drawings. Figure 1 shows the overall view of molten slag
granulation setup in the blast furnace. Molten iron and slag produced in blast
furnace 1 are removed through a tap hole 2 and separated in the cast house.
The first element in the cast house runner system is a refractory-lined trench in
its floor called trough 3. Molten iron and slag are collected in the trough as they
are cast from the blast furnace though the tap hole 2. Molten slag floats on the
iron and is separated from it by a skimmer 4. Iron flows under the skimmer into
the iron runner 5 and the slag held above the skimmer flows into a slag runner
6.
The molten slag goes to a blow box 7 where high-pressure water jets are applied
to it. Quenching with larger volumes of water instantaneously drops the
temperature of slag below the boiling point of water, forming fine sand-sized
particles in the process. Slag and water slurry thereafter flows through a conduit
8 into a slag pit 9. Slag slurry is de-watered by draining out the water from the
slag pit 9 and the wet granulated slag is discharged by an ejection conveyer 10
for further processing. Water separated from the slag is collected into a cooling
pond 11 as it flows down stream. Cooled by the cooling pond 11, It is reused in
the blow box 7 as the jet water. A pump controller 12 controls feed water
pumps 13 depending on the amount of slag.

Slag flow rate measurement system is implemented on the slag granulation
setup explained above. During the granulation process, water temperature rises
as the molten slag loses heat during quenching. This occurs in the blow-box 7
and runner 8. it is this rise in temperature that is sensed by the combination of
IR pyrometer 14 placed obliquely over the slurry conduit 8 and thermocouple 15
placed in the inlet water pipe. The temperature rise is input to the slag flow rate
calculation method on a real time basis.
Overall schematic representation of the system is shown in Figure 2. An IR
pyrometer 14 housed in a casing 20 to protect it from dust and corrosive
ambient condition is placed directly over the conduit 8 (Rgure 1) through which
the slag slurry flows after quenching. The pyrometer 14 is oriented such that it
picks up the temperatures of the slag slurry 30 through a rectangular slit 40 in
the top cover of the conduit 50. The pyrometer casing 20 is mounted on a
swiveling mounting 60 which helps aim the pyrometer at a suitable spot Dry air
purging provided in the pyrometer casing 20 not only helps in keeping the sensor
lenses clear of ambient dust and fumes but also helps dissipate the heat
collected from the high temperature environment around it. Signal from the
pyrometer 14 is sent to an interfacing panel 80 also placed in the cast house.
The interfacing panel houses a signal processing unit 70 for input temperature
signal from pyrometer 14, two temperature display units 80 to show the
temperature of the slag slurry and inlet water at a particular instance, power
supply 90 and an ADAM 100 to send signal to the control room.

Placed in the control room, remote from the cast house is an ADAM 110,
receiving the signals from the interfacing panel and a personal computer 120 to
run a program to calculate the slag flow rate. Slurry temperature measured by
the pyrometer and the inlet jet water temperature measured by the
thermocouple are the two inputs to the program that calculates the slag flow
rate using a relationship derived below.
As discussed above, during granulation slag loses heat to water and the heat lost
by slag is equal to the heat gained by water. Heat lost by slag has two
components, first, that lost by fall in its temperature, and second, release of the
latent heat of fusion on solidification. Hence, heat lost by slag is
ΔHS = msCppSΔTs + mSLs
Where ms is mass flow rate slag, Cps is the specific heat capacity of slag,ΔT s is
the fail in slag temperature (positive) during granulation and Ls is the latent heat
of fusion of slag.
Heat gained by water is spent partly in evaporating the water and partly in
raising its temperature. The heat spent in evaporation is small and it is
neglected. With this approximation heat gained by water is
ΔHw = mwCpwΔTw

where mw is the mass flow rate of water, Cp,w is the specific heat capacity of
water and ΔTW is the rise in water temperature in the granulation process.
Equating heat lost by slag with heat gained by water,
If we denote
and assume that they are constant, it follows from above equation,
Equation (1)
is the baseline equation for evaluating the slag flow rate. With value of the SFR
constant (k) known and real time reading of ATw taken as the difference
between the slag slurry temperature and the inlet water temperature, the slag
flow rate is available from the above equation.
We have seen that SFR constant is
(2)

Since, mw and ΔTS are not strictly constant so there is no exact evaluation of SFR
constant value, i.e. an exact value of constant k does not exist. To find the best
representative value of the constant that is consistent with our purpose, two
different approaches have been used.
One method of evaluating k approaches a limit (i.e. limiting value that is not
attained in practice) of k from below; in other words, the value always remains
less than k and is termed as ka1. This provides a lower bound to the value of k.
Another approach of evaluating k approaches a limit of k from above, i.e. always
remains larger than k and is termed as k32. This provides an upper bound to the
value of k.
Together, this can be expressed as

So, the value of k always lies within the bounds [ka1, ka2] and this is the domain
of error in k.
First approach to evaluate the value of k (ka1) uses Eq. (2), i.e.,

as the base equation. Here, values of Cp,w Cp,s & Ls are obtained from standard
handbooks, mass flow rate of water (mw) is available with blast furnace
instrumentation and ΔTS = Tis - Tes. To calculate the value ofΔTs, temperature
of the slag before granulation (Ts) is measured installing a temporary pyrometer

over the slag runner and exit temperature of the slag (Tes) is approximated equal
to the slag slurry temperature (Tes) measured by the IR pyrometer. However, in
actual Tes > Tew hence Tis - Tes approximating Tes = Tew will always be higher then the actual. Since this
appears in the denominator of Eq. (2), the value of ka1 thus obtained is always
on the lower side.
Second approach to evaluate the value of k (ka2) uses Eq. (1), i.e. k = ms/ ΔTW,
as the base equation. Here, ms = ms / ts and ΔTW = Tew — Tiw . To calculate the
value of ms, mass of the slag tapped in a day (ms) is recorded as per the belt
weight and total time of slag flow in a day (ts) as per the IR pyrometer reading
(sharp rise / fall in the pyrometer reading with start / stop of slag flow can be
used to record the timings for the same). ΔTW is calculated using the slag slurry
temperature (Tew ) measured by the IR pyrometer and inlet water temperature
(Tiw) measured by the thermocouple. Since wet slag weight as per the belt
weight is higher than the actual value, the value of ms comes out to be higher
and consequently, from Eq. (1), the value of ka2 thus obtained is always on the
higher side.
Fig.3a shows a plot of slag flow rate obtained from the above formulation for a
typical slag flow cycle. Same plot is displayed on a MMI in the blast furnace
control room as shown in fig. 3b.

Slag flow rate calculated by the program, apart from being displayed on the MMI
for operations supervision and control purposes, acts as an input to the pump
controller. A signal M* depending on the slag flow rate value is generated by the
PC. Pump controller regulates the jet water supply to the blow box as per the
received signal. Water input to the blow box is always maintained at a
predetermined base level and regulated by operating the stand-by pump as and
when required.
Figure. 4a shows the front view of the installed IR pyrometer. IR pyrometer with
the casing and the mounting arrangements can be seen.
Figure 4b shows the side view of the pyrometer with the slurry channel.
Figure 4c shows the interfacing panel with two temperature display units, one on
the left hand side showing the inlet water temperature and the other on the right
side showing the slag slurry temperature.
Slag flow rate measurement device described above, involves only a pyrometer
and a thermocouple resulting in a very simple and reliable system. Time lag in
predicting the slag flow rate is almost negligible resulting in rapid response of the
pump controller in case of the abrupt change in the slag flow rate. It helps in
efficient operation of the granulation process.




FIELD OF INVENTION
This invention relates generally to an apparatus for real time measurement of
mass flow rate of slag tapped from blast furnace. More specifically, the
invention relates to real time measurement within a precision band, flow rate of
molten slag discharged from a blast furnace.
BACKGROUND OF THE IHVEHTION
Blast furnace slag is a nonmttallic byproduct of the iron and steel making
process. The process starts with the extraction of iron from iron ore. In the
production of iron, iron ore, fluxes (limestone and / or dolomite) are charged into
a blast furnace along with coke as fuel to separate molten iron from other
materials. These impurities consisting of silicon and alumina combine with
calcium and magnesium to form molten slag.
When the blast furnace is tapped to release the molten iron, it flows from the
furnace with the molten slag floating on its upper surface. These two materials
are separated using a weir, the molten iron channeled to a holding vessel
(torpedo ladle) and the molten slag to a water crash facility where jet water of a
constant pressure is applied to it.
Quenching molten slag with large volumes of water produces granulated blast
furnace slag. The blast furnace slag is instantaneously brought to a temperature
below the boiling point of water, converting it to fine sand-sized particles in an
amorphous glassy form.

In the known system the slag and water slurry after quenching flows through a
conduit to the slag pit where the slag is de-watered. An ejection conveyer
empties wet granulated slag from the pit at a regular interval. A bad cell placed
in the ejection conveyer system gives weight of the slag tapped from the
furnace.
Belt scale output thus obtained suffers from significant time lag and is on a
higher side because of the moisture content of the slag. Moreover, this does not
provide instantaneous values in real time and is hence of no use to furnace
operations supervision and control. So, it is required to have a system that
provides accurate values of slag flow rate in real time with minimum lag.
An example of a slag flow rate measurement system is disclosed in document JP
11037819. It provides an image processing based system that measures the
slag flow sectional area, calculated from the width of the slag flowing in a V-
shaped conduit. Sectional area of stag flow and slag flow speed based on
inclination angle of conduit and slag viscosity acquired from the measured slag
temperature gives the slag flow rate.
Document JP 58144715, uses an ultrasonic wave current meter to measure the
flow speed of the slag from the blast furnace. Measured signal from the above
sensor and a level meter to measure the level of slag in blast furnace are used to
compute the slag flow rate.
In both the examples, however, the system is placed before the water crash
facility and is based on altogether different principles. Slag flow measurement
system has a complicated structure and is exposed to wear of runner, which may
reduce the accuracy of the system.

The main object of this invention is to provide a real time slag flow rate
measurement system that is capable of giving the slag flow rate with minimum
time lag and a high precision.
Another object of this invention is to provide a slag flow rate measurement
system that has a simplified structure.
These and other objects of the present invention are achieved by measuring in
real time, by means of a thermocouple the temperature of inlet water used for
quenching the slag and measuring the temperature of the slag and water slurry
by means of an infrared pyrometer located just above the conduit carrying the
slag and water slurry. The change in slurry/water temperature after slag
granulation is obtained in real time with minimum lag.
The temperature difference described above is multiplied by slag Mow rate (SFR)
constant to provide the slag flow rate. Evaluation of an exact value of SFR
constant is not possble as such a value does not exist. Hence two different
methods that calculate its bounds have been formulated. One approaches the
value of the constant from the lower side (below) and the other from above so
that the value of the constant lies between these two bounds and this represents
the degree of precision / domain of error in the value.

A feedback control using slag flow rate as a parameter is used to control the amount of
water required in granulation process. This apart from helping to improve the overall
efficiency of the granulation process, reduces the risk of water vapour explosion.
More importantly, the availability of measured values of slag flow rate in real time allow
the development of furnace models that facilitate supervision and control of furnace
operations.
Thus the present invention provides a slag flow rate measurement system for predicting
in real time the mass flow rate of slag tapped from a blast furnace with reference to the
signal produced from a pyrometer located above the slag conduit, characterized in that
said infrared pyrometer is placed obliquely to the slag flow for measuring the
temperature of the slag slurry in the conduit, and a thermocouple provided to measure
the inlet water temperature thus providing the temperature variation of the slag slurry,
said slag flow rate being calculated from a formula based on the temperature variation
thereby providing supervision and control of the blast furnace operations.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 shows a configuration of blast furnace granulation setup that employs the
molten slag flow rate measurement device of the present invention.
Figure 2 shows a configuration of molten slag flow rate measurement system of the
present invention.
Figure 3a shows a graph for typical slag flow cycle with slag flow rate plotted against
time.

Figure 3b shows the MMI depicting the slag flow rate in the blast furnace control
room.
Figure 4a shows the front view of the IR pyrometer used for slag flow rate
measurement.
Figure 4b shows the side view of the slag flow rate measurement setup with IR
pyrometer placed obliquely over the slag slurry channel.
DESCRIPTION OF PREFERRED EMBODIMENT
An embodiment of the present invention will now be described with reference to
the accompanying drawings. Figure 1 shows the overall view of molten slag
granulation setup in the blast furnace. Molten iron and slag produced in blast
furnace 1 are removed through a tap hole 2 and separated in the cast house.
The first element in the cast house runner system is a refractory-lined trench in
its floor called trough 3. Molten iron and slag are collected in the trough as they
are cast from the blast furnace though the tap hole 2. Molten slag floats on the
iron and is separated from it by a skimmer 4. Iron Mows under the skimmer into
the iron runner 5 and the slag held above the skimmer flows into a slag runner
6.

The molten slag goes to a blow box 7 where high-pressure water jets are applied
to it. Quenching with larger volumes of water instantaneously drops the
temperature of slag below the boiling point of water, forming fine sand-sized
particles in the process. Slag and water slurry thereafter flows through a conduit
8 into a slag pit 9. Slag slurry is de-watered by draining out the water from the
slag pit 9 and the wet granulated slag is discharged by an ejection conveyer 10
for further processing. Water separated from the slag is collected into a cooling
pond 11 as it flows down stream. Cooled by the cooling pond 11, It is reused in
the blow box 7 as the jet water. A pump controller 12 controls feed water
pumps 13 depending on the amount of slag.
Slag flow rate measurement system is implemented on the slag granulation
setup explained above. During the granulation process, water temperature rises
as the molten slag loses heat during quenching. This occurs in the blow-box 7
and conduit 8. it is this rise in temperature that is sensed by the combination of
IR pyrometer 14 placed obliquely over the slurry conduit 8 and thermocouple 15
placed in the inlet water pipe. The temperature rise is input to the slag flow rate
calculation method on a real time basis.
Overall schematic representation of the system is shown in Figure 2. An IR
pyrometer 14 housed in a casing 20 to protect it from dust and corrosive
ambient condition is placed directly over the conduit 8 (Figure 1) through which

the slag slurry flows after quenching. The pyrometer 14 is oriented such that it
picks up the temperatures of the slag slurry 30 through a rectangular slit 40 in
the top cover of the conduit 50. The pyrometer casing 20 is mounted on a
swiveling unit 60 which helps aim the pyrometer at a suitable spot. Dry air
purging provided in the pyrometer casing 20 not only helps in keeping the sensor
lenses clear of ambient dust and fumes but also helps dissipate the heat
collected from the high temperature environment around it. Signal from the
pyrometer 14 is sent to an interfacing panel 80 also placed in the cast house.
The interfacing panel houses a signal processing unit 70 for input temperature
signal from pyrometer 14, two temperature display units 80 to show the
temperature of the slag slurry and inlet water at a particular instant, power
supply 90 and an ADAM 100 to send signal to the control room.
Placed in the control room, remote from the cast house is an ADAM 110,
receiving the signals from the interfacing panel for calculating the slag flow rate
in a processor. This processor can be a personal computer 120 to run a program
to calculate the slag flow rate. Slurry temperature measured by the pyrometer
and the inlet jet water temperature measured by the thermocouple are the two
inputs to the program that calculates the slag flow rate using a relationship
derived below.

As discussed above, during granulation slag loses heat to water and the heat lost by
slag is equal to the heat gained by water. Heat lost by slag has two components, first,
that lost by fall in its temperature, and second, release of the latent heat of fusion on
solidification. Hence, heat lost by slag is

where ms is mass flow rate slag, Cps is the specific heat capacity of slag, ΔTs is the fall
in slag temperature (positive) during granulation and LS is the latent heat of fusion of
slag.
Heat gained by water is spent partly in evaporating the water and partly in raising its
temperature. The heat spent in evaporation is small and it is neglected. With this
approximation heat gained by water is

where mw is the mass flow rate of water, Cps is the specific heat capacity of water and
ΔTw is the rise in water temperature in the granulation process.
Equating heat lost by slag with heat gained by water,


If we denote
and assume that they are constant, it follows from above equation,
Equation (1)
is the baseline equation for evaluating the slag flow rate. With value of the SFR constant
(k) known and real time reading of Δ Tw taken as the difference between the slag slurry
temperature and the inlet water temperature, the slag flow rate is available from the
above equation.
We have seen that SFR constant is
(2)
Since, mw and ΔTS are not strictly constant so there is no exact evaluation of SFR
constant value, i.e. an exact value of constant k does not exist. To find the best
representative value of the constant that is consistent with our purpose, two different
approaches have been used.

One method of evaluation k approaches a limit (i.e. limiting value that is not attained in
practice) of k from below; in other words, the value always remains less than k and is
termed as kal. This provides a lower bound to the value of k.
Another approach of evaluating k approaches a limit of k from above, i.e. always
remains larger than k and is termed as ka2. This provides an upper bound to the value
of k.
Together, this can be expressed as

So, the value of k always lies within the bounds [kal,ka2] and this is the domain of error
in k.
First approach to evaluate the value of k uses Eq. (2), i.e.

as the base equation. Here, values of Cp(W,CP/S & Ls are obtained from standard
handbooks, mass flow rate of water (mw) is available with blast furnace
instrumentation and ΔTs = T1s -Vs. To calculate the value of ΔTS, temperature
of the slag before granulation (T1s) is measured installing a temporary pyrometer

over the slag runner and exit temperature of the slag (Tes) is approximated equal to the
slag slurry temperature (Tew) measured by the IR pyrometer. However, in actual Tes >
Tew hence Tes - Tes will always be higher than the actual. Since this appears in the denominator of Eq. (2),
the value of kal thus obtained is always on the lower side.
Second approach to evaluate the value of k uses Eq. (1) i.e. k =
ms / ΔTw as the base equation. Here, ms = ms / ts and / ΔTw =Tew - T1w To calculate
the value of, ms, mass of the slag tapped in a day (ms) is recorded as per the belt
weight and total time of slag flow in a day (ts) as per the IR pyrometer reading (sharp
rise / fall in the pyrometer reading with start / stop of slag flow can be used to record
the timings for the same). ΔTw is calculated using the slag slurry temperature (Tew)
measured by the IR pyrometer and inlet water temperature (T1w) measured by the
thermocouple. Since wet slag weight as per the belt weight is higher than the actual
value, the value of ms comes out to be higher and consequently, from Eq.(l), the value
of ka2 thus obtained is always on the higher side.
Fig. 3a shows a plot of slag flow rate obtained from the above formulation for a typical
slag flow cycle. Same plot is displayed on a MMI in the blast furnace control room as
shown in Fig. 3b.

Slag flow rate calculated by the program, apart from being displayed on the MMI
for operations supervision and control purposes, acts as an input to the pump
controller. A signal M* depending on the slag flow rate value is generated by the
PC. Pump controller regulates the jet water supply to the blow box as per the
received signal. Water input to the blow box is always maintained at a
predetermined base level and regulated by operating the stand-by pump as and
when required.
Figure. 4a shows the front view of the installed IR pyrometer. IR pyrometer with
the casing and the mounting arrangements can be seen.
Figure 4b shows the side view of the pyrometer with the slurry channel.
Figure 4c shows the interfacing panel with two temperature display units, one on
the left hand side showing the inlet water temperature and the other on the right
side showing the slag slurry temperature.
Slag flow rate measurement device described above, involves only a pyrometer
and a thermocouple resulting in a very simple and reliable system. Time lag in
predicting the slag flow rate is almost negligible resulting in rapid response of the
pump controller in case of the abrupt change in the slag flow rate. It helps in
efficient operation of the granulation process.
WE CLAIM:
1. A slag flow rate measurement system for predicting in real time the mass flow
rate of slag tapped form a blast furnace with reference to the signal produced
from a pyrometer located above the slag conduit, characterized in that:
- said infrared pyrometer is placed obliquely to the slag flow for measuring
the temperature of the slag slurry in the conduit; and
- a thermocouple provided to measure the inlet water temperature thus
providing the temperature variation of the slag slurry;
- slag slurry flow rate being calculated from a formula based on the
temperature variation thereby providing supervision and control of the
blast furnace operations.
2. The system as claimed in claim 1, wherein said slag flow rate calculation formula
based on the variation in slag slurry temperature with respect to the inlet water
temperature, wherein :
- said change in temperature multiplied by slag rate (SFR) constant gives
the slag flow rate;
- a slag flow rate constant value devised using two different techniques,
one approaching the limit of the constant from the lower side and the
other from the above;
- the difference between these limits providing the domain of existence of
the constant and thus the verifiable precision band of the evaluated flow
rate.
3. A slag rate measurement system for predicting in real time the mass flow rate of
slag tapped form a blast furnace as herein described and illustrated in the
accompanying drawings.

Documents:

162-KOL-2005-(07-12-2011)-FORM-27.pdf

162-KOL-2005-(22-08-2012)-FORM-27.pdf

162-kol-2005-abstract.pdf

162-kol-2005-claims.pdf

162-kol-2005-correspondence.pdf

162-kol-2005-description (complete).pdf

162-kol-2005-description (provisional).pdf

162-kol-2005-drawings.pdf

162-kol-2005-examination report.pdf

162-kol-2005-form 1.1.pdf

162-kol-2005-form 1.pdf

162-kol-2005-form 13.pdf

162-kol-2005-form 18.pdf

162-kol-2005-form 2.pdf

162-kol-2005-form 3.pdf

162-kol-2005-form 5.pdf

162-kol-2005-gpa.pdf

162-kol-2005-others.pdf

162-kol-2005-reply to examination report.pdf

162-kol-2005-specification.pdf


Patent Number 247531
Indian Patent Application Number 162/KOL/2005
PG Journal Number 16/2011
Publication Date 22-Apr-2011
Grant Date 18-Apr-2011
Date of Filing 14-Mar-2005
Name of Patentee TATA STEEL LIMITED
Applicant Address RESEARCH AND DEVELOPMENT DIVISION JAMSHEDPUR
Inventors:
# Inventor's Name Inventor's Address
1 KARAMVIR TATA STEEL LIMITED, RESEARCH AND DEVELOPMENT DIVISION, JAMSHEDPUR 831 001
2 BHATTACHARYA ARYA K TATA STEEL LIMITED, RESEARCH AND DEVELOPMENT DIVISION, JAMSHEDPUR 831 001
3 MUKHERJEE ASHIS TATA STEEL LIMITED, RESEARCH AND DEVELOPMENT DIVISION, JAMSHEDPUR 831 001
4 PAL INDRAJIT TATA STEEL LIMITED, RESEARCH AND DEVELOPMENT DIVISION, JAMSHEDPUR 831 001
5 JHA D N TATA STEEL LIMITED, RESEARCH AND DEVELOPMENT DIVISION, JAMSHEDPUR 831 001
PCT International Classification Number C21B 5/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA