Description:FORM 2
THE PATENT ACT 1970
(39 OF 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

1 TITLE OF THE INVENTION :
MOULD MONITORING SYSTEM FOR SLAB CASTERS WITH REAL-TIME MOULD THERMAL PROFILE VISUALISATION.



2 APPLICANT (S)

Name : STEEL AUTHORITY OF INDIA LIMITED.

Nationality : Indian.

Address : Research & Development Centre for Iron & Steel,
Doranda, Ranchi, Jharkhand, India. PIN-834002.






3 PREAMBLE TO THE DESCRIPTION

COMPLETE

The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present invention relates to a Mould monitoring and breakout control system for slab casters. More particularly, the present invention is directed to a system for Mould monitoring and breakout control in slab casters with real-time mould thermal profile visualisation.

BACKGROUND OF THE INVENTION

Steel melting shop is an integral unit where molten hot metal from blast furnace is further processed to form molten steel in Basic Oxygen Furnace (BOF), Ladle Heating Furnace (LHF), etc. Molten steel is converted into slab in Continuous casters.

Continuous casting is a process where molten steel is converted into slabs, molten steel is tapped through shroud into a tundish and the tapped to mould through a Submerged Entry Nozzle (SEN).

Continuous caster plays a vital role in steel production; heat distribution issues in caster will lead to defect in slabs or Impending breakouts. So continuous monitoring of thermal heat transfer inside mould during casting will helps in reducing the defects and also helps in early detection of sticker to prevent breakouts.

Mould is an open box structure having four faces two broad faces and two narrow faces made of copper with water boxes which helps to extract heat from the strand and helps in formation of shell growth. Improper heat transfer inside the mould may result in sticker breakout and some defects in slab formation, which causes quality issues during subsequent processing of the slab. A breakout leads to production delays which effects on productivity and also causes mechanical damages inside caster.

The number of breakouts happening in the casters is predominantly increasing. So the present invention is directed to develop an Indigenous Mould monitoring system for slab casters with a real time mould thermal profile to visualise the thermal activities happening inside the mould. So that it will help in assessment of situation, predict and prevent the Sticker breakouts.

OBJECTS OF THE INVENTION

The basic object of the present invention is directed to a Mould monitoring and breakout control system for slab casters with real-time mould thermal profile visualisation.

A further object of the present invention is directed to a Mould monitoring and breakout control system for slab casters so that the thermal activities happening inside the mould can be visualized for assessment of situation, predict and prevent the impending Sticker breakouts.

A still further object of the present invention is directed said mould monitoring and breakout control system which would include mould instrumentation, Data Acquisition System (DAS) with a real time Mould thermography to visualize the activities happening inside mould.

A still further object of the present invention is directed said mould monitoring and breakout control system which would ensure increased caster availability and reduce mechanical inventory consumption due to reduced number of breakouts.

A still further object of the present invention is directed said mould monitoring and breakout control system wherein Real-time heat flux screen would help in monitoring the shell formation inside the mould.

SUMMARY OF THE INVENTION
The basic aspect of the present invention is directed to a Mould monitoring and breakout control system for slab casters comprising:

Mould system including copper plate surrounded by water box;

Necked down bolts for fixing the water box and mould copper plate;

said necked down bolts supporting spring loaded thermocouples to capture liquid steel temperature inside mould in real-time basis wherein said thermocouple passing through the hole of bolt and touching the body of copper plate so that the bolt acts as thermowell;

Remote Input Output (RI/O) operatively connected to said thermocouple for receiving temperature signals from said thermocouples in the mould;

Said Remote Input Output (RI/O) adapted to capture and process TC signals for further transmission to a Programmable Logic Controller (PLC) for mapping of all faces of mould captured in real-time;

Said PLC communicating with automation unit of caster for process parameter signals and command exchange;

Said PLC operatively connected to a Supervisory Control and data Acquisition (SCADA) server for data input and generating programmed output back to said PLC;

Said Supervisory Control and data Acquisition (SCADA) adapted for capturing data at micro second level for faster action, operatively connected to Human machine Interface (HMI) for display of real time mould thermograph, real time trends of process parameters and related PLC logic control enabling mould monitoring for impending breakout and activating related process control in caster slabs.

A further aspect of the present invention is directed to said Mould monitoring and breakout control system for slab casters comprising mould copper plate is fitted with said necked down bolts and said spring loaded thermocouples comprising mineral insulated sheath protecting thermocouple elements and said spring helps thermocouple to attain spring tension during operation, for desired real time mould thermal mapping.

A still further aspect of the present invention is directed to said Mould monitoring and breakout control system for slab casters comprising said monitoring and control means including HMI screen displaying real-time mould thermograph of temperature including features of Postmortem analysis and other process signals including casting speed, mould level.

A still further aspect of the present invention is directed to said Mould monitoring and breakout control system for slab casters comprising mould heat flux screens involving temperature and mould cooling signals related to monitoring shell growth inside the mould.

Another aspect of the present invention is directed to said Mould monitoring and breakout control system for slab casters comprising signal conversion means for converting electrical to optical and vice versa at multiple levels and related fiber optics connection.

Yet another aspect of the present invention is directed to said Mould monitoring and breakout control system for slab casters comprises PLC level convertor for two-way data communication between PLC and server for regular updates.

Above and other aspects 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 DRAWINGS
Figure 1: shows the schematic details of specially designed necked down bolt.
Figure 2: shows the details of specially designed spring loaded thermocouple.
Figure 3: shows schematic diagram of Data Acquisition System (DAS).

Figure 4 shows the detailed schematic picture of the copper plate, instrumented mould assembly with specially designed thermocouple and bolt assembly.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

The present invention is directed to design, development and implementation of Mould Monitoring and breakout control system for slab casters with real-time mould thermal profile visualisation to predict and prevent impending sticker breakouts.

Accompanying Figure 1 shows the details of specially designed necked down bolts that illustrates the following components:
Part A is through bolt which is used for fixing the water box and mould copper plate, thermocouple will be passing through the hole of bolt and touching the body of copper plate. This bolt acts as thermowell.
Part B & C are Spacers of different size helps in sealing.
Part D represents the nuts used for tightness.
Part E, F & G represents O-rings of different sizes helps in preventing water leakages.

Accompanying Figure 2 shows the specially designed spring loaded thermocouple that illustrates the following components:
Part 1 is Mineral insulated sheath protecting thermocouple elements,
Part 2 is the Stopper that helps in protecting damage of thermocouple due to extra force during installation,
Part 3 is the spring which helps thermocouple to attain spring tension during operation,
Part 4 is Washer which helps in preventing water leakages,
Part 5 represents threaded fitting which helps the assembly to fix with bolt assembly,
Part 6 represents miniature plug which will be connected to RI/o station through which data of particular thermocouple will be transferred.

The mould monitoring system has been designed and developed with mould instrumentation, Data Acquisition system (DAS) with a real time Mould thermography to visualize the activities happening inside mould. Detail data acquisition scheme have been shown schematically in accompanying Figure 3.

Accompanying Figure 4 shows the detailed schematic picture of the copper plate, instrumented mould assembly with specially designed thermocouple and bolt assembly in real-time.
The above-mentioned system is designed such that the mapping of all faces of mould will be captured in real-time which helps in monitoring the activities being carried inside the mould during casting which was earlier not available.
This SCADA system is designed such that data is being captured at a micro second level which helps in taking faster action.

Various features of Instrumentation and control of mould monitoring system of present invention are as follows:

1. Moulds of slab caster were adapted to instrumented mould by design modification and incorporation of mechanical and instrumentation items.
2. Necked down bolts were designed to accommodate thermocouples which act as thermo well. Notches were made on copper plate to accommodate the tips of thermocouples.
3. Mould copper plates were assembled with specially designed necked down bolts after modifications and water test were carried out to check leakages for broad and narrow faces.
4. Spring loaded thermocouples were specially designed for this application to capture liquid steel temperature inside the mould in real-time basis.
5. Special Junction boxes were designed and mounted on mould frame to house the thermocouple connectors through which temperature signals from thermocouples on mould to Remote Input Output (RI/O) station are being transmitted via compensating cables.
6. RI/O station is designed with universal analog modules, interface modules and other accessories to capture and process TC signals for further communication to Programmable Logic Controller (PLC) via Fibre Optic (FO) backbone.
7. PLC communicates with existing automation system of the caster for process parameter signals and command exchange. Data from PLC is transmitted to Supervisory Control and Data Acquisition (SCADA) server. Calculations are done as per algorithm deployed in the server and output is communicated back to the PLC.
8. On the basis of data captured by SCADA system, Human machine interface (HMI) screens were developed to display the Real time mould thermograph, real-time trends of process parameters like mould face temperatures, caster speed, mould level, stopper rod position, cooling parameters, etc.
9. HMI screens were developed to display Mould heat flux based on real-time mould cooling parameters and associated algorithm implemented in PLC Logic.
10. HMI screens were deployed in all client machines which provide an insight of all thermal activities happening inside mould and helps in taking necessary corrective action to avoid impending breakouts.

It is thus possible by way of the present invention to provide the Mould monitoring and breakout control system with Mould instrumentation, Data Acquisition system with a real time thermal visualisation which have been put on trial in caster-I, SMS-II, of Applicant’s Rourkela Steel Plant whereby following benefits were achieved:

i. Early detection of sticker happening inside the mould provides guidance to the caster operator to take necessary corrective actions to prevent the impending breakout.
ii. Improved caster availability,
iii. Reduction in the mechanical inventory consumption due to reduced number of breakouts,
iv. Real-time heat flux screen helps in monitoring the shell formation inside the mould.

This invention can be advantageously implemented in all Continuous Slab Casters for early detection of sticking tendency of shell with copper mould. Accordingly necessary action may be taken by operator to prevent the impending sticker breakout. The outcome of the innovation is tested and the system can be readily retrofitted and horizontally transferred to continuous slab caster in SMS unit of various steel plants.

, Claims:We Claim:

1. Mould monitoring and breakout control system for slab casters comprising:

Mould system including copper plate surrounded by water box;

Necked down bolts for fixing the water box and mould copper plate;

said necked down bolts supporting spring loaded thermocouples to capture liquid steel temperature inside mould in real-time basis wherein said thermocouple passing through the hole of bolt and touching the body of copper plate so that the bolt acts as thermowell;

Remote Input Output (RI/O) operatively connected to said thermocouple for receiving temperature signals from said thermocouples in the mould;

Said Remote Input Output (RI/O) adapted to capture and process TC signals for further transmission to a Programmable Logic Controller (PLC) for mapping of all faces of mould captured in real-time;

Said PLC communicating with automation unit of caster for process parameter signals and command exchange;

Said PLC operatively connected to a Supervisory Control and data Acquisition (SCADA) server for data input and generating programmed output back to said PLC;

Said Supervisory Control and data Acquisition (SCADA) adapted for capturing data at micro second level for faster action, operatively connected to Human machine Interface (HMI) for display of real time mould thermograph, real time trends of process parameters and related PLC logic control enabling mould monitoring for impending breakout and activating related process control in caster slabs.

2. The Mould monitoring and breakout control system for slab casters as claimed in claim 1 comprising mould copper plate is fitted with said necked down bolts and said spring loaded thermocouples comprising mineral insulated sheath protecting thermocouple elements and said spring helps thermocouple to attain spring tension during operation, for desired real time mould thermal mapping.

3. The Mould monitoring and breakout control system for slab casters as claimed in anyone of claims 1 or 2 comprising said monitoring and control means including HMI screen displaying real-time mould thermograph of temperature including features of Postmortem analysis and other process signals including casting speed, mould level.

4. The Mould monitoring and breakout control system for slab casters as claimed in anyone of claims 1 to 3 comprising mould heat flux screens involving temperature and mould cooling signals related to monitoring shell growth inside the mould.

5. The Mould monitoring and breakout control system for slab casters as claimed in anyone of claims 1 to 4 comprising signal conversion means for converting electrical to optical and vice versa at multiple levels and related fiber optics connection.

6. The Mould monitoring and breakout control system for slab casters as claimed in anyone of claims 1 to 5 comprises PLC level convertor for two way data communication between PLC and server for regular updates.

Dated this the 31st day of January, 2023
Anjan Sen
Of Anjan Sen & Associates
(Applicant’s Agent)
IN/PA-199