FIELD OF THE INVENTION
The present invention relates to a system for measuring the length of bloom crop at the
end shear/saw of Blooming mills in steel plants. More particularly, the invention is
directed to a photosensor based online sensing and measurement system for measuring
the length of crops of hot blooms in presence of sparkles. Advantageously, the system of
the invention involves a plurality of photosensors in an array/stack put across the bloom
at an angle of 45° with respect to the rolling line for viewing the front/back(crop) end of
bloom even if there is no space to view the bloom perpendicularly. Importantly, the
system of the invention is capable of measuring lengths of bloom crop ranging from
150mm to 400mm with an accuracy of 0-50mm with separate sets of photosensor stack
for the front crop and the back crop and works satisfactorily even if the gap between two
successive blooms crop is as low as 50mm. Moreover, the system of the invention is
adapted to eliminate the problems associated with crop counting error due to load
current of shear motor or generation of sparkles of molten metal during
sensing/measurement. The bloom crop length measuring system of the present invention
thus ensure accurate bloom crop length measurement and counting the number thereof
in a simple, low cost yet highly reliable manner for advantageous application in steel
plant to precisely compute the yield.
BACKGROUND ART
The bloom casting in continuous caster is followed by further section reductions in rolling
line, in order to proceed the as cast bloom section to next stage of hot rolling, there is
the need for front/back cropping of the as cast bloom section to avoid undesired rolling
defects. Conventionally the crop/shear of bloom is monitored and measured by using
CCD camera which is installed to sense the end for determining the length of crop to
desired accuracy. It is experienced in the art that such CCD camera for imaging the
bloom for length measurement suffers from limitation like inability to run for longer
period under severe site conditions. The cost of CCD camera also is very high which need
frequent repair/replacement making such prior art systems unreliable and expensive.
There has been therefore a need in the art to developing a low cost system for bloom
crop length measurement and counting for blooming mill in steel plants which would be
simple yet accurate and operate with required reliability for longer period without
interruption of production. The present invention attempts to solve the problem of the
prior art system by providing a photosensor based bloom crop/shear sensing and
measuring system which would be simple, cost effective and realiable as well as adapted
to operate for longer duration in adverse working environment in rolling mill site
maintaining desired accuracy/precision in measurements.
OBJECTS OF THE INVENTION
The basic object of the present invention is directed to developing a simple, low cost yet
reliable system for bloom crop length measurement at blooming mill in presence of
sparkles involving photosensor based sensing and measurement adapted to ensure
desired accuracy of measurement.
Another object of the present invention is directed to providing a system for online
sensing/measuring length of bloom crop shear at blooming mill wherein the system is
sturdy and durable to ensure desired measurement accuracy of bloom crop for longer
period in spite of harsh work environment at plant site.
A further object of the present invention is directed to a system for online
sensing/measuring length of bloom crop shear at blooming mill wherein the photosensor
stack at front/back end of bloom are disposed at 45° inclination with the rolling line so as
to enable installation even in absence of space for perpendicular viewing from either end.
A still further object of the present invention is directed to a system for online
sensing/measuring length of bloom crop shear at blooming mill wherein the system is
adapted to measure the lengths of bloom crop ranging from 150mm to 400mm with a
measuring accuracy of 0-50mm.
A still further object of the present invention is directed to a system for online
sensing/measuring length of bloom crop shear at blooming mill wherein the system is
adapted to work satisfactorily even when the gap between the successive bloom crops is
as low as 50mm.
A still further object of the present invention is directed to a system for online
sensing/measuring length of bloom crop shear at blooming mill wherein the system is
free from problems in counting the crop arising due to load current of motor or
generation of sparkles of molten metal.
SUMMARY OF THE INVENTION
The basic aspect of the present invention is thus directed to a system for online
measurement of the length of bloom crop in presence of sparkles in blooming mill,
comprising
a first photosensor stack selectively disposed with respect to the rolling line and
focusing on the crop length for bloom front crop;
a second photosensor stack selectively disposed with respect to the rolling line and
focusing on the crop length for bloom back crop;
a logic circuit adapted to ascertain the length of front/back bloom crop based on
signal from said sensors and filtering the sparkles;
a crop display unit to display the front and/or back crop length of bloom enabling
cutting operation at desired length;
counter means to count the number of pieces of respective crop length for display on
the display unit.
Another aspect of the present invention is directed to said system for online
measurement of the length of bloom crop wherein said front crop stack is kept at an
angle of 45° with respect to rolling line and focuses for the crop length in the range of
150 mm to 400 mm.
Also in said system for online measurement of the length of bloom crop according to the
invention, said back crop stack is kept at an angle of 45° with respect to rolling line
and focuses for the crop length in the range of 150 mm to 400 mm.
A further aspect of the present invention is directed to a system for online measurement
of the length of bloom crop wherein said front crop stack consists of 6 phototranslstors
kept at an interval of 50 mm for measuring the crop length with a least count of 50
mm.
According to yet another aspect of the present invention is directed to said system for
online measurement of the length of bloom crop comprising a plurality of photosensors in
front crop stack selectively spaced adapted to measure the crop length in the range of
with a least count of 50 mm and said back crop stack consists of 6 phototransistors kept
at an interval of 50 mm for measuring the crop length with a least count of 50 mm.
A further aspect of the present invention is directed to a system for online measurement
of the length of bloom crop wherein said back crop stack is kept at an angle of 45° with
respect to rolling line and focuses for the crop length in the range of 150 mm to 400
mm.
Another important aspect of the present invention is directed to said system for online
measurement of the length of bloom crop wherein said system is adapted to measure the
length of bloom crop with a accuracy of 0-50 mm and works satisfactorily even with
the gap between two successive bloom crops as low as 50 mm.
A still further aspect of the present invention is directed to a system for online
measurement of the length of bloom crop wherein said counter means comprising
Counters 1-5 for counting the number of pieces of respective crop length, after passing
through logical circuit in which signal of 1st photosensor is ANDED with inverted signal of
2nd photosensor and so on such that signals derived from rest photosensors are ANDED
for knowing the length of crop and filtering the sparkles.
A still further aspect of the present invention is directed to a system for online
measurement of the length of bloom crop wherein said crop display unit is adapted such
that operator sees the front/back crop length in display unit and cuts the crop and said
display unit displays the number of pieces for respective crop lengths.
The present invention and its objects and advantages are described in greater details
with reference to the accompanying non limiting illustrative drawings.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1: is the schematic illustration for sensing bloom front crop using photosensors of
the system according to the present invention.
Figure 2: is the schematic illustration for sensing bloom back crop involving photosensors
of the system according to the present invention.
Figure 3: is the schematic illustration of the crop length/ counting display panel of the
bloom crop length measurement system according to the present invention.
Figure 4: is the schematic illustration of the logic circuit for determining the crop
length/counting for display in the bloom crop length measurement system according to
the present Invention.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWINGS
The present invention relates to a photosensor based online sensing and measurement
system for measuring the length of crops and also counting of hot blooms in presence of
sparkles at shear machine of Blooming mills in steel plants.
Reference is first invited to the accompanying Figure 1 that schematically illustrates the
arrangement for sensing bloom front crop using photosensors of the system according to
the present invention. More particularly, the invention is concerned about developing a
simple, low cost but highly reliable way to sense the length of crop in steel plant for
calculating yield.
It is apparent from the Figure 1 that the front crop stack consists of 6 phototransistors
and they are kept at a interval of 50 mm for measuring the crop length with a least
count of 25 mm. The stack is kept at an angle of 45° with respect to rolling line and
focuses for the crop length ranging between 150 mm to 400 mm. On the arrival of a
bloom, the operator sees the crop length in crop display unit and cuts the crop.
Similarly, back crop stack consists of 6 phototransistors are kept at a interval of interval
of 50 mm for measuring the crop length with a least count of 50 mm. Accomapnylng
Figure 2 schematically illustrates the arrangement for sensing bloom back crop involving
photosensors of the system according to the present invention. The photosensor stack is
kept at an angle of 45° with respect to rolling line and focuses for the crop length in the
range of 150 mm to 400 mm. During back end cropping of bloom also, the operator sees
the crop length in display unit and cuts the crop .
Reference is now invited to the accompanying Figure 3 that schematically illustrates the
crop length/ counting display panel of the bloom crop length measurement system
according to the present invention.
The number of pieces for respective crop length is counted by Counter 1-5, either for the
front or back crop, after passing through the logical circuit as shown in Figure 4, in
which signal of 1st photosensor is ANDED with inverted signal of 2nd photosensor. In this
way signals derived from rest photosensors are ANDED for knowing the length of crop
and filtering the sparkles. The photosensor based crop length measurement system
according to the invention is thus capable of sensing and measuring the bloom crop
length, either at front or back crop, in the presence of sparkles of molten metal.
It is thus possible by way of the present invention to providing a simple, cost effective
and reliable system for sensing and precise measurement of bloom crop length with
desired accuracy and counting the number of pieces for respective crop length displayed
on the display panel. The system of the invention is thus capable of providing the exact
quantification and measurements of the bloom crop/shear length so as to minimize
wastes and improve upon the productivity and yield of blooming mill. The bloom crop
length measuring system of the present invention is having the advantageous feature of
performing satisfactorily for longer duration in adverse environmental site condition with
equal accuracy even when the sensors are installed at a selective angular orientation
with rolling line in absence of adequate space for perpendicular viewing from front end
and with a gap between successive bloom crops as low as 50mm. The present crop
length is thus capable of wide scale application in blooming mills of steel plants with
significant cost advantage.
We Claim:
1. A system for online measurement of the length of bloom crop in presence of sparkles
in blooming mill, comprising
a first photosensor stack selectively disposed with respect to the rolling line and
focusing on the crop length for bloom front crop;
a second photosensor stack selectively disposed with respect to the rolling line and
focusing on the crop length for bloom back crop;
a logic circuit adapted to ascertain the length of front/back bloom crop based on
signal from said sensors and filtering the sparkles;
a crop display unit to display the front and/or back crop length of bloom enabling
cutting operation at desired length;
counter means to count the number of pieces of respective crop length for display on
the display unit.
2. A system for online measurement of the length of bloom crop as claimed in claim 1
wherein said front crop stack is kept at an angle of 45° with respect to rolling line and
focuses for the crop length in the range of 150 mm to 400 mm.
3. A system for online measurement of the length of bloom crop as claimed in any one of
claims 1 or 2 wherein said back crop stack is kept at an angle of 45° with respect to
rolling line and focuses for the crop length in the range of 150 mm to 400 mm.
4. A system for online measurement of the length of bloom crop as claimed in anyone of
claims 1 to 3 wherein said front crop stack consists of 6 phototransistors kept at an
interval of 50 mm for measuring the crop length with a least count of 50mm.
5. A system for online measurement of the length of bloom crop as claimed in anyone of
claims 1 to 4 comprising a plurality of photosensors in front crop stack selectively spaced
adapted to measure the crop length in the range of with a least count of 50 mm and said
back crop stack consists of 6 phototransistors kept at an interval of 50 mm for
measuring the crop length with a least count of 50 mm.
6. A system for online measurement of the length of bloom crop as claimed in any one of
claims 1 to 5 wherein said back crop stack is kept at an angle of 45° with respect to
rolling line and focuses for the crop length in the range of 150 mm to 400 mm.
7. A system for online measurement of the length of bloom crop as claimed in any one of
claims 1 to 6 wherein said system is adapted to measure the length of bloom crop with
a accuracy of 0-50 mm and works satisfactorily even with the gap between two
successive bloom crops as low as 50 mm.
8. A system for online measurement of the length of bloom crop as claimed in any one of
claims 1 to 7 wherein said counter means comprising Counters 1-5 for counting the
number of pieces of respective crop length, after passing through logical circuit in which
signal of 1st photosensor is ANDED with inverted signal of 2nd photosensor and so on such
that signals derived from rest photosensors are ANDED for knowing the length of crop
and filtering the sparkles.
9. A system for online measurement of the length of bloom crop as claimed in any one of
claims 1 to 8 wherein said crop display unit is adapted such that operator sees the
front/back crop length in display unit and cuts the crop and said display unit displays the
number of pieces for respective crop lengths.
10. A system for online measurement of the length of bloom crop in presence of sparkles
in blooming mill substantially as hereindescribed with reference to the accompanying
illustrative drawings.

The invention relates to a photosensor based online sensing and measurement system
for measuring the length of crops of hot blooms in presence of sparkles in blooming mill.
A plurality of photosensors are put in separate array/stack across the bloom at an angle
of 45° with respect to the rolling line for viewing the front/back(crop) end of bloom and
focusing the crop length even if there is no space to view the bloom perpendicularly.
Importantly, the system of the invention is capable of measuring lengths of bloom crop
ranging from 150mm to 400mm with an accuracy of 0-50mm and works satisfactorily
even if the gap between two successive blooms crop is as low as 50mm. The bloom crop
length measuring system ensures accurate bloom crop length measurement and counting
the number thereof in a simple, low cost yet highly reliable manner for advantageous
application in steel plant to precisely compute the yield of blooming mill.