FIELD OF THE INVENTION
The present invention relates to an improved oil based mould lubrication system for a multi-
strand billet caster. More Particularly, the present invention is directed to providing an oil
based mould lubrication system for a multi-strand billet caster comprising AC(Alternating
Current) motors, WVF(Variable Voltage Variable Frequency) drives, and pumps, having a
working and standby pump-motor arrangement for recirculation of oil and also having a
standby lubrication circuit which can be manually connected to any of the working strands.
The system also has improved and relatively dirt free mould oil refilling system with
arrangement of intermediate tank with barrel stand for placing the drum, and refilling tank.
The system has a standby portable trolley mounted refilling motor and pump arrangement
with quick couplings to connect to any one of the two refilling systems in the two casters.
The oil based mould lubrication system for a multi-strand billet caster according to the
present invention thus ensure uninterrupted controlled lubrication of the walls of moulds of
the caster in all strands and thus favouring improved productivity and efficiency of
continuous casting in steel plants.
BACKGROUND OF THE INVENTION
It is well known that the continuous casting plants in large integrated steel plants under
takes continuous slab/billet casting in multiple strands without interruptions wherein the
molten steel is poured into the moulds for continuous casting. The moulds are subjected to
very high temperature. The moulds keep oscillating for continuously moving the cast billet
with just solidified shell downward. The mould and steel interface needs to be lubricated for
easy oscillatory movement of mould and withdrawal of the billet with a just formed outer
solidified shell and liquid steel still within the shell. If the shell breaks due to undue stresses
on the solidified shell due to lack of lubrication, the liquid steel comes out of the shell and a
breakout occurs which results in strand stoppage and loss of productivity.
Conventional oil based mould lubrication system in one of the applicants continuous casting
plant was equipped with DC (Direct Current) motors and pump having only six lubrication
circuits for six strands. In this existing arrangement, DC motors with rheostat were used for
controlling the speed of the pump for controlling the lubricant discharge rate coming from
the pump. Accurate control was not possible for setting the discharge rate and it was
dependent on operator experience. To compensate for the lack of accuracy in flow rate
setting, the operators used to keep the lubrication pump speed setting such as to have flow

of oil on the higher side to avoid lubrication failure in the moulds. There were six lubrication
circuits for the six working strands but there was no provision for any standby lubrication
circuit which could be used in case of failure of any one of the working circuits for six
strands. Also there was no provision of quick coupling and non return valves for connecting
any such standby lubrication circuit to any one of the six working circuits which might fail.
Consequently, in case of failure in any one of the strands' lubrication pump or motor, there
occurred unwanted loss of productivity due to non availability of the strand on account of
lubrication failure. The conventional mould lubrication systems in the two billet casters had
identical features. Moreover, there was no working and standby motor and pump
arrangement along with associated valve arrangement for recirculation of oil in the header
for intake of lubrication pumps. The conventional system had only one motor pump system
for recirculation. Moreover, there was no arrangement for dirt protection of refilling tank as
the tank was open from top.
There has been thus a need in the art to developing an oil based lubrication system for
reliable lubrication of the moulds of each of the caster strand which would on one hand
precisely control and maintain the desired flow rate of lubricant in each mould and at the
same time provide necessary standby arrangement in case of any failure of lubrication in
any of the strands including required refilling of oil to reservoir and thus ensure
uninterrupted casting process with improved productivity.
OBJECTS OF THE INVENTION
The basic object of the present invention is thus directed to provide an improved oil based
lubrication system for moulds in continuous caster for a six strand billet caster to precisely
control and maintain desired discharge rate of lubricant in moulds in a consistent manner
without failure to ensure enhanced caster productivity.
A further object of the present invention is directed to providing an improved oil based
mould lubrication system for a multi-strand billet caster involving VVVF grade AC
(Alternating Current) motor, VWF(Variable Voltage Variable Frequency) drive instead of DC
motors with rheostat for closely controlling the speed of the lubrication circuit pumps for
controlling the lubricant discharge rate coming from the pumps to the moulds, avoiding
reliance on operator experience, and providing extra oil flow for compensating for the
expected deficiency of oil flow due to inaccuracy of conventional DC based control system.

A still further object of the present invention is directed to providing an improved oil based
mould lubrication system for a multi-strand billet caster involving a standby lubrication
circuit, in addition to six lubrication circuits for the six working strands, which can be
manually connected to any of the six working circuits for six strands of the billet caster, in
case of lubrication failure in any of the six strands due to motor or pump failure.
A still further object of the present invention is directed to providing an improved oil based
mould lubrication system for a multi-strand billet caster involving an arrangement of flexible
hose pipe, quick couplings and non-return valves required for connecting the standby circuit
to any one of the six working strand circuits.
A still further object of the present invention is directed to providing an improved oil based
mould lubrication system for a multi-strand billet caster which incorporates an electrical
panel comprising VVVF drives for the six working strands and one standby strand for
controlling the respective VVVF grade motor speed for control of respective lubricant pump
speed which will eventually result in controlled flow of lubricant oil to the moulds through
the pipelines and distributor blocks fitted in the mould, alongwith other components also for
control of the total system and is interfaced with the existing PLC control system of the
casters.
A still further object of the present invention is directed to providing an improved oil based
mould lubrication system for a multi-strand billet caster involving a manual standby
recirculation motor-pump which can be used in case of failure of main recirculation pump-
motor which can be manually switched over from the electrical panel. Also valve
arrangement and electrical selector switch for manual changeover between working and
standby motor-pump has been provided.
A still further object of the present invention is directed to providing an improved oil based
mould lubrication system for a multi-strand billet caster wherein a lubricant refilling system
is provided which will facilitate easy filling of the refilling tank as well as control the dust
ingress into the oil from the dusty environment of the shop.
Yet another object of the present invention is directed to providing an improved oil based
mould lubrication system for a multi-strand billet caster wherein a portable trolley mounted

standby refilling motor-pump arrangement along with flexible tubing is provided which shall
be used if the refilling motor or pump fails with provision of a return line from main
reservoir to refilling tank for redirecting overflow from main reservoir to the refilling tank.
A still further object of the present invention is directed to providing an improved oil based
mould lubrication system for a multi-strand billet caster to improve reliability, and
operability in case of failure in any one of the strands' lubrication pump or motor and avoid
productivity loss due to non availability of the strand on account of lubrication failure.
SUMMARY OF THE INVENTION
The basic aspect of the present invention is thus directed to an oil based mould lubrication
system in a multi-strand billet caster in continuous casting shop, comprising
lubrication circuits for working strands in said multi-strand billet caster;
VVVF grade AC (Alternating Current) motor and pump for working and standby
lubrication circuits with VVVF (Variable Voltage Variable Frequency) drive adapted
for closely controlling the speed of the pump for controlling the lubricant discharge
rate coming from the pump for said working circuits and the standby lubrication
circuit.
A further aspect of the present invention is directed to an oil based mould lubrication
system comprising (i) a main reservoir, with accessories such as level indicator, level gauge,
temperature switch, air breather, electrical heater for oil; (ii) oil recirculation system having
one working and one standby motor-pump arrangement with valves for isolation and duplex
pressure line filter, pressure relief valve; (iii)six working circuits each having VVVF grade
motor, lubrication oil pump, pressure relief valve, pressure gauge with isolation valve,
minimesh coupling, quick release coupling for standby connection, and (iv) one standby
lubrication having VVVF grade motor, lubrication oil pump, pressure relief valve, pressure
gauge with isolation valve, minimesh coupling, quick release coupling for connection as
standby to any of the six working circuits.
A still further aspect of the present invention is directed to an oil based mould lubrication
system wherein said standby lubrication circuit is manually connected to any of the six

working circuits for six strands of the billet caster, through an arrangement of flexible hose
pipe, quick release couplings, non return valves and flexible hose provided in the circuit.
A further aspect of the present invention is directed to an oil based mould lubrication
system comprising a working and a standby motor-pump arrangement for recircultion of oil
in the pressurized header, with isolation valves and electrical switch adapted for switching
over to the standby pump in case of working pump/motor failure or vice versa.
A still further aspect of the present invention is directed to an oil based mould lubrication
system comprising
six lubrication circuits for the six working strands in said multi-strand billet caster;
a standby lubrication circuit which can be used in case of failure of any one of the
circuit for six working circuits;
VVVF grade AC (Alternating Current) motor and pump with VVVF (Variable Voltage
Variable Frequency) drive for lubrication circuits and standby circuit for closely
controlling the speed of the pump for controlling the lubricant discharge rate coming
from the pump for said six working circuits and also said standby circuit;
arrangement of quick couplings and non-return valves for connecting the standby
lubrication circuit to any one of the six working strand lubrication circuits;
electrical panel comprising said VVVF drives for the six working strands and one
standby strand for controlling the VVVF grade motor speed for control of lubricant
pump speed for controlled flow of lubricant oil to the moulds through the pipelines
and distributor blocks fitted in the mould and also housing components for control of
the total system and is interfaced with the existing PLC control system of casters;
a standby recirculation motor-pump which can be used in case of failure of main
recirculation pump-motor;
a refilling system to facilitate easy filling of the refilling tank as well as control of the
dust ingress into the oil from the dusty environment;

a portable trolley mounted standby refilling motor-pump arrangement along with
flexible tubing provided to be used if the refilling motor or pump fails;
the portable refilling motor-pump can be connected locally to the power line of
working motor, so that the same operating logic is applicable to the standby motor-
pump when connected.
a return line provided from main reservoir to refilling tank for redirecting overflow
from main reservoir to the refilling tank.
A still further aspect of the present invention is directed to an oil based mould lubrication
system, wherein said system is provided with one working and one standby motor-pump
arrangement, for recirculation of oil in the pressurized header, along with isolation valves
and electrical selection switch for switching over to the standby pump in case of working
pump/motor failure or vice versa.
Yet another aspect of the present invention is directed to an oil based mould lubrication
system, wherein said standby recirculation motor-pump is adapted for manual switching
over from the electrical panel.
A further aspect of the present invention is directed to an oil based mould lubrication
system comprising valve arrangement and electrical selector switch for manual changeover
between working and standby motor-pump.
A still further aspect of the present invention is directed to an oil based mould lubrication
system wherein said refilling system comprising barrel stand and intermediate tank based
system for filling oil in refilling tank, comprising refilling tank of steel sheet with accessories
such as level indicator, level gauge, motor, pump, strainer, isolation valves, pressure gauge,
pressure relief valve, air breather, quick release coupling for connecting standby refilling
pump, and pressure line filter.
Another aspect of the present invention is directed to an oil based mould lubrication system
wherein said refilling system of lubricant oil involving pressure relief valve and other
components adapted for parallel connection with portable standby refilling pump-motor.

Yet another aspect of the present invention is directed to an oil based mould lubrication
system wherein said distributor blocks fitted in the mould comprising 1:4 distributor valve
for dividing oil flow to individual mould equally to all the four walls of the mould.
The objects and advantages of the present invention are described hereunder in greater
details with reference to the following accompanying non limiting illustrative drawings.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
Figure 1: shows the schematic illustration of the oil based mould lubrication system of the
prior art using DC (Direct Current) motors, and pumps, having six lubrication circuits for six
strands without any standby arrangement.
Figure 2: is the schematic diagram of the mould lubrication system for multi strand caster
according to the present invention showing the different components including the standby
circuit for connecting to any of the six strands manually in case of motor or pump failure in
any of the six working circuits. The schematic also shows other features such as standby
recirculation motor-pump and isolation valve arrangement, refilling arrangement, standby
portable refilling arrangement, return line from main reservoir to refilling tank etc.
Figure 3: is the schematic illustration of the general arrangement of mould lubrication
system showing main reservoir and accessories.
Figure 4: is the schematic diagram showing the general arrangement of refilling system
which is a relatively dirt free improved refilling system having mould oil refilling unit with
provision for intermediate tank with stand for placing the drum and refilling tank.
Figure 5: shows the schematic illustration of the Electrical Panel of the Mould Lubrication
System according to the present invention which houses VVVF drive and other electrical
components for the six working strands and also for standby circuit motor-pump control in
communication with operator control pendent with display indications.
Figure 6: is the schematic illustration of the portable trolley mounted standby refilling
pump-motor arrangement for the oil refilling system according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING FIGURES
The present invention relates to an improved oil based mould lubrication system for a multi-
strand billet caster involving AC(Alternating Current) motors, VVVF(Variable Voltage Variable
Frequency) drives, and pumps, having a working and standby pump-motor arrangement for
recirculation of oil and also having a standby lubrication circuit which can be manually
connected to any of the working strands.
Accompanying Figure 1 shows the prior art oil based mould lubrication system using DC
(Direct Current) motors and pump having six lubrication circuits for six strands without any
standby arrangement. In this earlier arrangement, DC motors with rheostat were used for
controlling the speed of the pump for controlling the lubricant discharge rate coming from
the pump. Accurate control was not possible for setting the discharge rate and it was
dependent on operator's experience. To compensate for lack of accuracy, the operators were
keeping flow rates of oil on the higher side to avoid lubrication failure in the moulds. There
were only six lubrication circuits for the six working strands and there was no provision for a
standby lubrication circuit which could be used in case of failure of any one of the working
circuits for six strands. Also there was no provision of quick coupling and non return valves
for connecting the standby lubrication circuit to any one of the six working circuits. Also
there was no working / standby motor and pump arrangement along with associated valve
arrangement for refilling of oil.
The present invention thus provides for an improved arrangement of AC (Alternating
Current) motor, VVVF (Variable Voltage Variable Frequency) drive, and pump based system
for oil-based mould lubrication for six strand billet caster and implemented in two such
casters of the applicants plant. Accompanying Figure 2 show the schematic diagram of the
mould lubrication system for multi strand caster according to the present invention showing
the different components including the standby circuit for connecting to any of the six
strands manually in case of motor or pump failure in any of the six working circuits.
VVVF grade AC (Alternating Current) motor, VVVF(Variable Voltage Variable Frequency)
drive has been introduced, instead of DC motors with rheostat, for closely controlling the
speed of the six working lubrication circuits and standby lubrication circuit pumps for
controlling the lubricant discharge rate coming from the pump. A standby lubrication circuit

is provided in the new system which can be manually connected to any of the six working
circuits for six strands of the billet caster. This standby circuit can be used in case of
lubrication failure in any of the six strands due to motor or pump failure. There are six
lubrication circuits for the six working strands and there is provision for a standby circuit
which can be used in case of failure of any one of the circuit for six strands. Also there is the
arrangement of quick couplings and non-return valves for connecting the standby circuit to
any one of the six working strand circuits. An electrical panel comprising VVVF drives for the
six working strands and one standby strand for controlling the VVVF grade motor speed for
control of lubricant pump speed which will eventually result in controlled flow of lubricant oil
to the moulds through the pipelines and distributor blocks fitted in the mould. The electrical
panels houses other components also for control of the total system and is interfaced with
the existing PLC control system of the two casters.
Importantly, to improve the performance reliability of such a mould lubrication system of
continuous caster, a manual standby recirculation motor-pump is introduced which can be
used in case of failure of main recirculation pump-motor. It can be manually switched over
from the electrical panel. Also valve arrangement and electrical selector switch for manual
changeover between working and standby motor-pump has also been provided.
Advantageously, in the above mould lubrication system for multi strand casters, a lubricant
refilling system is provided which will facilitate easy filling of the refilling tank as well as
control the dust ingress into the oil from the dusty environment of the shop. Also a portable
trolley mounted standby refilling motor-pump arrangement along with flexible tubing has
been provided which shall be used if the refilling motor or pump fails. The portable refilling
motor-pump can be connected locally to the power line of working motor, so that the same
operating logic is applicable to the standby motor-pump when connected. Additionally, a
return line has been provided from main reservoir to refilling tank for overflow from main
reservoir to be re-directed to the refilling tank.
Thus according to the present invention there is provided an improved arrangement of oil
based mould lubrication system in a multi-strand billet caster in continuous casting shop
involving VVVF Drive and VVVF grade AC motors, and pump arrangement with a standby
circuit which can be manually connected to any of the six working circuits for six strands of
the billet caster. The standby circuit can be used in case of lubrication failure in any of the
six strands due to motor or pump failure. The system has been provided with an improved

refilling system which is relatively dirt free. The system has also been provided with one
working and one standby motor-pump arrangement with isolation valves and electrical
selection switch for switching over to the standby pump in case of working pump/motor
failure or vice versa. The system has also been provided with a portable trolley mounted
motor pump arrangement as a standby for refilling motor pumps of the two units.
Identical mould lubrication systems as described above have been implemented in the two
billet casters of Continuous Casting Shop in the applicants' steel plant. The said invention of
improved arrangement of oil based mould lubrication system is suitable for multi-strand
billet caster in continuous casting shop. The various features of the system and their
operation are described hereunder in further details:
Refilling System - The refilling system comprises refilling tank of steel sheet with
accessories such as level indicator, level gauge, motor, pump, strainer, isolation valves,
pressure gauge, pressure relief valve, air breather. Pressure line filter has been provided.
The oil pipeline is of SS304. A return line of mild steel has been provided for return of
overflow oil from main reservoir to the refilling tank.
A barrel stand and intermediate tank based system for filling oil in refilling tank has been
provided. The refilling system of lubricant oil has arrangement for parallel connection of
portable standby refilling pump-motor using the same pressure relief valve and pressure
line filter as in main refillign circuit.
The above arrangement has made possible a relatively dirt free improved refilling system
having mould oil refilling unit. The system has also been provided with a portable trolley
mounted motor pump arrangement as a standby for refilling motor pumps of the two units.
Trolley Mounted Standby Refilling Motor-pump - A portable trolley mounted standby
refilling motor-pump arrangement along with flexible tubing was provided which shall be
used if the refilling motor or pump fails.
Mould Lubrication Unit - The system has a main reservoir, with accessories such as level
indicator, level gauge, temperature switch, air breather, electrical heater for oil, Oil
recirculation system having one working and one standby motor-pump arrangement with
valves for isolation and duplex pressure line filter, pressure relief valve, Six working circuits
each having VVVF grade motor, lubrication oil pump, pressure relief valve, pressure gauge

with isolation valve, minimesh coupling, quick release coupling for standby connection, and
One standby lubrication circuits having VVVF grade motor, lubrication oil pump, pressure
relief valve, pressure gauge with isolation valve, minimesh couplings, quick release
coupling for connection as standby to any of the six working circuits.
The standby lubrication circuit can be manually connected to any of the six working circuits
for six strands of the billet caster, through an arrangement of quick release couplings, non
return valves and flexible hose provided in the circuit.
The recirculation system having one working and one standby motor-pump arrangement
with isolation valves and electrical selection switch facilitates for switching over to the
standby pump in case of working pump/motor failure or vice versa.
Field piping - All field piping is of SS304 and end connection to the distributor is through a
flexible tubing and quick coupling.
Accompanying Figure 3 illustrates the general arrangement of mould lubrication system
main reservoir and accessories.
Accompanying Figure 4 illustrates the general arrangement of refilling system which is a
relatively dirt free improved refilling system having mould oil refilling unit with arrangement
of intermediate tank with stand for placing the drum and refilling tank.
Main Electrical Panel - Main electrical Panel has VVVF drives for six working and one
standby circuit and also house other electrical components.
Control Potentiometers in existing mould operator pendants (MOP) - Control
potentiometers have been provided one each in the six existing mould operator pendants
(MOP) of each caster for controlling the respective VVVF drive of the working circuit motor
and pump, and control the lubricant discharge rate by setting for appropriate speed of the
motor.
Standby Operator Control Panel - An operator control panel for standby circuit in each
caster has been installed for controlling the VVVF drive of the standby circuit motor when it

is connected and electrically switched on in case of lubrication pump or motor failure in any
of the six working strands.
Field Cabling - Associated power and control cables have been provided for supplying
power to the mould lubrication unit as well as interfacing the system with existing PLC of
the respective casters for controlling the system along with the caster operation.
Accompanying Figure 5 illustrates the Electrical Panel of the Mould Lubrication System
which houses VVVF drive and other electrical components. The control potentiometers for
six working strands have been provided in existing mould operator pendent for the six
working strands. A new operator control panel with control potentiometer and indications
has been provided for standby circuit motor-pump control.
The two mould lubrication systems each have a main electrical panel housing the VVVF drive
and other electrical components of the system.
The potentiometers for controlling the drives have been installed in the existing mould
operator pendant of the six working strand, which has saved cost. The standby circuit motor
speed control potentiometer is installed in a separate operator control panel near the
operator control pendant for the six strands on the caster platform. The standby circuit
when connected in case of any one working circuit failure can be controlled through this
operator control panel.
The system is designed to have separate power feeding point for each strand as well as for
standby strand to avoid the chance of power tripping in all strands at once, had there been
a single power supply for all the seven lubrication circuits.
Accompanying Figure 6 illustrates the portable trolley mounted standby refilling pump-
motor arrangement for the oil refilling system. The system has been provided with the
portable trolley mounted motor pump arrangement as a standby for refilling motor pumps
of the two units.
The above figures show the VVVF Drive and VVVF grade AC motors based and oil based
mould lubrication system with improved circuit having six working and one standby circuits
for lubrication. The above figures also show standby lubrication circuit which can be

manually connected to any of the six working circuits for six strands of the billet caster.
Provision of flexible hose, quick release couplings and non return valves for connection of
standby lubrication pump to the six working strands is also shown. It has also been
provided with one working and one standby motor-pump arrangement with isolation valves
and electrical selection switch for switching over to the standby pump or vice versa in case
of working pump/motor failure.
The system utilizes SS304 pipelines from the individual circuits up to the end connection
where the flexible tube connects the pipeline and individual mould's distributor block, which
distributes the rated flow of oil to the four faces of the mould through the 4 outlets of the
distributor blocks.
It is thus possible by way of the present invention to providing an improved oil based mould
lubrication system for a multi-strand billet caster, comprising AC(Alternating Current)
motors, WVF(Variable Voltage Variable Frequency) drives, and pumps for oil-based mould
lubrication system for a multi-strand billet caster, having a working and standby pump-
motor arrangement for recirculation of oil and having a standby lubrication circuit which can
be manually connected to any of the working strands. The system also has improved and
relatively dirt free mould oil refilling system with arrangement of intermediate tank with
stand for placing the drum and refilling tank. The system has a standby portable trolley
mounted refilling motor and pump arrangement with quick couplings to connect to any of
the casters. The oil based mould lubrication system for multi-strand billet caster according
to the present invention thus ensure reliable and efficient operation of the continuous caster
avoiding failure of lubrication system, increased caster availability and higher productivity in
steel plants.

We Claim:
1. An oil based mould lubrication system in a multi-strand billet caster in continuous
casting shop, comprising
lubrication circuits for working strands in said multi-strand billet caster;
VVVF grade AC (Alternating Current) motor and pump with VVVF (Variable Voltage
Variable Frequency) drive for working lubrication circuits and standby lubrication
circuits of oil adapted for closely controlling the speed of the pump for controlling the
lubricant discharge rate coming from the pump for said working circuits and standby
circuit.
2. An oil based mould lubrication system as claimed in claim 1 comprising a working
and a standby motor-pump arrangement for recirculation of oil in the pressurized
header, along with isolation valves and electrical selection switch adapted for
switching over to the standby pump in case of working pump/motor failure or vice
versa.
3. An oil based mould lubrication system as claimed in anyone of claims 1 or 2
comprising six lubrication circuits for the six working strands in said multi-strand
billet caster;
a standby lubrication circuit which can be used in case of failure of any one of the
circuit for six strands;
VVVF grade AC (Alternating Current) motor and pump for recirculation of oil with
VVVF (Variable Voltage Variable Frequency) drive, for closely controlling the speed of
the pump for controlling the lubricant discharge rate coming from the pump for said
six working circuits and also said standby circuit;
arrangement of quick couplings and non-return valves for connecting the standby
circuit to any one of the six working strand circuits;
electrical panel comprising said VVVF drives for the six working strands and one
standby strand for controlling the VVVF grade motor speed for control of lubricant

pump speed for controlled flow of lubricant oil to the moulds through the pipelines
and distributor blocks fitted in the mould and also housing components for control of
the total system and is interfaced with the existing PLC control system of casters;
a standby recirculation motor-pump which can be used in case of failure of main
recirculation pump-motor;
a refilling system to facilitate easy filling of the refilling tank as well as control of the
dust ingress into the oil from the dusty environment;
a portable trolley mounted standby refilling motor-pump arrangement along with
flexible tubing provided to be used if the refilling motor or pump fails;
a return line provided from main reservoir to refilling tank for redirecting overflow
from main reservoir to the refilling tank.
4. An oil based mould lubrication system as claimed in anyone of claims 1 to 3, wherein
said system is provided with one working and one standby motor-pump
arrangement for recirculation of oil in the pressurized header along with isolation
valves and electrical selection switch for switching over to the standby pump in case
of working pump/motor failure or vice versa.
5. An oil based mould lubrication system as claimed in anyone of claims 2 to 4, wherein
said standby refilling motor-pump is adapted for manual connection at local
electrical junction box using the same power cable for working motor-pump.
6. An oil based mould lubrication system as claimed in anyone of claims 1 to 5,
comprising valve arrangement and electrical selector switch for manual changeover
between working and standby motor-pump of recirculation system.
7. An oil based mould lubrication system as claimed in anyone of claims 3 to 6, wherein
said refilling system comprising barrel stand and intermediate tank based system for
filling oil in refilling tank, comprising refilling tank of steel sheet with accessories
such as level indicator, level gauge, motor, pump, strainer, isolation valves, pressure
gauge, pressure relief valve, air breather, and pressure line filter.

8. An oil based mould lubrication system as claimed in anyone of claims 3 to 7, wherein
said refilling system of lubricant oil involving pressure relief valve and other
components adapted for parallel connection with portable standby refilling pump-
motor.
9. An oil based mould lubrication system as claimed in anyone of claims 1 to 8,
comprising (i) a main reservoir, with accessories such as level indicator, level gauge,
temperature switch, air breather, electrical heater for oil; (ii) oil recirculation system
having one working and one standby motor-pump arrangement with valves for
isolation and duplex pressure line filter, pressure relief valve; (iii)six working circuits
each having VVVF grade motor, lubrication oil pump, pressure relief valve, pressure
gauge with isolation valve, minimesh coupling, quick release coupling for standby
connection, and (iv) one standby lubrication having VVVF grade motor, lubrication oil
pump, pressure relief valve, pressure gauge with isolation valve, minimesh coupling,
quick release coupling for connection as standby to any of the six working circuits.
10. An oil based mould lubrication system as claimed in anyone of 1 to 9, wherein said
standby lubrication circuit is manually connected to any of the six working circuits
for six strands of the billet caster, through an arrangement of quick release
couplings, non return valves and flexible hose provided in the circuit.
11. An oil based mould lubrication system as claimed in anyone of claims 3 to 10,
wherein said distributor blocks fitted in the mould comprising 1:4 distributor valve
for dividing oil flow to individual mould equally to all the four walls of the mould.

ABSTRACT

An oil based mould lubrication system for a multi-strand billet caster is disclosed involving
AC(Alternating Current) motors, VWF(Variable Voltage Variable Frequency) drives, and
pumps, having a working and standby pump-motor arrangement for recirculation of oil at
precisely controlled rate, working lubrication circuit for each strand and a standby
lubrication circuit which can be manually connected to any of the working strands in case of
any failure. The system also has relatively dirt free mould oil refilling system with
arrangement of intermediate tank with stand and a standby portable trolley mounted
refilling motor and pump arrangement with quick couplings to connect to any one of the two
refilling systems in the two casters. The oil based mould lubrication system for a multi-
strand billet caster ensure uninterrupted lubrication of the walls of moulds of the caster in all strands and thus favouring improved productivity and efficiency of continuous casting
plants.