Claims:1. A method for real-time monitoring of a heat treatment process, the method comprising acts of:
receiving, by a computing unit (2), temperature data of fluid flowing in a furnace (3) comprising a plurality of specimens (4), from a control unit (1) at predetermined time intervals, wherein the control unit (1) is associated with the furnace (3);
determining, by the computing unit (2), temperature value of each of the plurality of specimens (4) in the furnace (3), based on the temperature data of the fluid at predetermined time intervals; and
indicating, by the computing unit (2), the temperature value of each of the plurality of specimens (4) determined by the computing unit (2), on an indication unit (5) associated with the computing unit (2).

2. The method as claimed in claim 1, wherein the temperature data of the fluid flowing in the furnace (3) is detected by the control unit (1) through at least one sensor (6) interfaced with the control unit (1).

3. The method as claimed in claim 1, wherein one or more data including dimensions of each of the plurality of specimens (4), a plurality of pre-set temperature values, and predetermined time intervals for the heat treatment process are stored in a memory unit (7) associated with the computing unit (2).

4. The method as claimed in claims 1 and 3 comprises act of comparing the temperature value of each of the plurality of specimens (4) determined by the computing unit (2) with each of the plurality of pre-set temperature values stored in the memory unit (7).

5. The method as claimed in claim 4 comprises act of providing a first indication during heating, when the temperature value of each of the plurality of specimens (4) reaches one of the plurality of pre-set temperature values.

6. The method as claimed in claim 4 comprises act of providing a second indication during heating, when the temperature value of each of the plurality of specimens (4) reaches one of the plurality of pre-set temperature values.

7. The method as claimed in claim 4 comprises act of providing a third indication during heating, when the temperature value of each of the plurality of specimens (4) reaches one of the pre-set temperature values.

8. The method as claimed in claim 4 comprises act of providing a fourth indication during cooling, when the temperature value of each of the plurality of specimens (4) reaches one of the pre-set temperature values.

9. The method as claimed in claim 1, wherein the heat treatment process is a batch annealing process.

10. The method as claimed in claim 1, wherein the plurality of specimens (4) is cold rolled steel.

11. The method as claimed in claim 1, wherein the fluid flowing in the furnace (3) is gas.

12. The method as claimed in claim 1, wherein the indication unit (5) provides indication of temperature value of each of the plurality of specimens (4) as at least one of audio format, visual format and combination of audio and visual format.

13. A system (100) for real-time monitoring of a heat treatment process, the system (100) comprising:
a control unit (1) associated with a furnace (3) and configured to detect temperature of fluid flowing in the furnace (3) at predetermined time intervals; and
a computing unit (2) interfaced with the control unit (1), wherein the computing unit (2) is configured to:
receive, the temperature data of the fluid flowing in the furnace (3) from the control unit (1);
determine, temperature value of each of a plurality of specimens (4) in the furnace (3), based on the temperature data of the fluid detected by the control unit (1) at predetermined time intervals; and
indicate the temperature value of each of the plurality of specimens (4) on an indication unit (5) associated with the computing unit (2).

14. The system (100) as claimed in claim 13 comprises at least one sensor (6) provisioned in the furnace (3), wherein the at least one sensor (6) is interfaced with the control unit (1) to monitor the temperature of the fluid flowing in the furnace (3).

15. The system (100) as claimed in claim 13 comprises a memory unit (7) associated with the computing unit (2), configured to store one or more data including dimensions of each of the plurality of specimens (4), a plurality of pre-set temperature data, and predetermined time intervals for the heat treatment process.

16. The system (100) as claimed in claim 13, wherein the indication unit (5) is at least one of an audio indication unit and a visual indication unit.

17. A batch annealing furnace interfaced with a system (100) as claimed in claim 13.
, Description:TECHNICAL FIELD
The present disclosure generally relates to a field of material science and metallurgy. Particularly, but not exclusively the present disclosure relates to heat treatment process. Further, embodiments of the present disclosure disclose a system and a method for real-time monitoring of batch annealing process.

BACKGROUND OF THE DISCLOSURE
In manufacturing technology, most of the components are manufactured using various primary manufacturing processes. Some of the components find applications in different sectors include, but are not limited to, automotive industries, consumer products, light and heavy duty machineries. Conventionally, heat treatment process is carried out based on application of the product or specimen. Heat treatment is carried out using techniques include, but are not limited to, annealing, normalising, hot rolling, quenching, and the like. During the heat treatment process, microstructures of the specimen are modified when the specimen undergoes a sequence of heating and cooling operations. As a result of heat treatment, the specimens undergo phase transformation influencing mechanical properties like strength, ductility, toughness, hardness, drawability etc. The purpose of heat treatment is to increase service life of a product by improving its strength, hardness etc. or prepare the material for improved manufacturability.

Conventionally, heat treatment process is carried out on the specimens of various dimensions based on a predetermined recipe. The predetermined recipe includes thermal points plotted for a particular specimen based on its dimensions and specific product requirement. The predetermined recipe also includes details for heating and cooling the specimen for predetermined intervals of time, to obtain required material as per requirement. This predetermined recipe is calculated using the analysis tools and is stored as data for carrying-out heat treatment process. Such procedure of using predetermined recipe, is commonly employed in heat treatment process includes, but not limited to, annealing including batch annealing process. In the batch annealing process, specimens in the form of coils are stacked one over the other over a base structure. The stacked specimens are covered by an air-tight cylindrical cover. On top of the air-tight cylindrical cover, a furnace with provisions for burners is mounted. In between the air-tight cylindrical cover and the outer surface of the specimens, a provision for fluid flow is provided. The fluid flow in between the air-tight cover and the outer surface of the specimens enable indirect heat transfer from the burners to the specimen. The fluid flow in between the air-tight cover and outer surface of the specimens also enable cooling. The heating and cooling of the specimen in such furnace is achieved by regulating the burners and the fluid flow rate at predetermined intervals. Conventionally, the predetermined intervals for regulating the burners and fluid flow rate are determined by at least one of numerical analysis of the specimens or by simulation analysis of the specimen using analysis tools. Such predetermined intervals are calculated in terms of time periods for various steps in the heat treatment process.

However, in the aforementioned technique of heat treatment process the heating and cooling time calculations are carried out based on mathematical models, before commencement of the heat treatment cycle. Thus, these timings for heat treatment process are strictly adhered and followed during heat treatment. However, there would be lot of disturbances or failures during the heat treatment process due to power fluctuations, power failure, improper fluid flow, and the like. This would result in undesirable conditions during heat treatment, and the target temperatures may not achieved within prescribed time limit. This condition leads to under or over heat treatment of the specimens which would lead to failure of specimen when used in various applications.

In the light of the foregoing discussion, there is a need to develop a system and a method for real time monitoring of heat treatment process to overcome one or more limitations stated above.

SUMMARY OF THE DISCLOSURE
One or more drawbacks of conventional methods of heat treatment of specimens as described in the prior art are overcome, and additional advantages are provided through the system and method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure.

In one non-limiting embodiment of the present disclosure, a method for real-time monitoring of a heat treatment process is disclosed. The method comprises acts of receiving, by a computing unit, temperature data of fluid flowing in a furnace comprising a plurality of specimens, from a control unit at predetermined time intervals, wherein the control unit is associated with the furnace. The method further comprises determining, by the computing unit, temperature value of each of the plurality of specimens in the furnace, based on the temperature data of the fluid at predetermined time intervals. The method also comprises act of indicating, by the computing unit, the temperature value of each of the plurality of specimens determined by the computing unit, on an indication unit associated with the computing unit.

In an embodiment, the temperature data of the fluid flowing in the furnace is detected by the control unit through at least one sensor interfaced with the control unit.

In an embodiment, one or more data including dimensions of each of the plurality of specimens, a plurality of pre-set temperature values, and predetermined time intervals for the heat treatment process are stored in a memory unit associated with the computing unit.

In an embodiment, the temperature value of each of the plurality of specimens determined by the computing unit is compared with each of the plurality of pre-set temperature values stored in the memory unit.

In an embodiment, a first indication during heating is provided when the temperature value of each of the plurality of specimens reaches one of the plurality of pre-set temperature values.

In an embodiment, a second indication during heating is provided when the temperature value of each of the plurality of specimens reaches one of the plurality of pre-set temperature values.

In an embodiment, a third indication during heating is provided, when the temperature value of each of the plurality of specimens reaches one of the pre-set temperature values.

In an embodiment, a fourth indication during cooling is provided, when the temperature value of each of the plurality of specimens reaches one of the pre-set temperature values.

In an embodiment, the heat treatment process is a batch annealing process, and the plurality of specimens is cold rolled steel.

In an embodiment, the fluid flowing in the furnace is gas.

In an embodiment, the indication unit provides indication of temperature value of each of the plurality of specimens as at least one of audio format, visual format and combination of audio and visual format.

In another non-limiting embodiment of the present disclosure, a system for real-time monitoring of a heat treatment process is disclosed. The system comprises a control unit associated with a furnace and is configured to detect temperature of fluid flowing in the furnace at predetermined time intervals. The system also comprises a computing unit interfaced with the control unit. The computing unit is configured to receive the temperature data of the fluid flowing in the furnace from the control unit. The computing unit is also configured to determine temperature value of each of a plurality of specimens in the furnace, based on the temperature data of the fluid detected by the control unit at predetermined time intervals. The computing unit is further configured to indicate the temperature value of each of the plurality of specimens on an indication unit associated with the computing unit.

In an embodiment, at least one sensor is provisioned in the furnace. The at least one sensor is interfaced with the control unit to monitor the temperature of the fluid flowing in the furnace.

In an embodiment, the system comprises a memory unit associated with the computing unit. The memory unit is configured to store one or more data including dimensions of each of the plurality of specimens, a plurality of pre-set temperature data, and predetermined time intervals for the heat treatment process.

In an embodiment, the indication unit is at least one of an audio indication unit and a visual indication unit.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The novel features and characteristics of the disclosure are set forth in the appended description. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

Figure 1 illustrates block diagram of a system for real-time monitoring of heat treatment process in accordance with an exemplary embodiment of the present disclosure.

Figure 2 illustrates a schematic view of a set-up used for batch annealing process in accordance with some embodiments of the present disclosure.

Figure 3 illustrates a thermal plot for carrying out the batch annealing process in accordance with some embodiments of the present disclosure.

Figure 4 illustrates flow chart showing a method for real time monitoring of a heat treatment process in accordance with some embodiments of the present disclosure.

Figure 5a illustrates top view of the specimen positioned in the set-up used for batch annealing process, showing a radial discretised region in accordance with some embodiments of the present disclosure.

Figure 5b illustrates front view of the specimen of FIG. 5a, showing an axial discretised region in accordance with some embodiments of the present disclosure.

Figure 5c illustrates front view of the of the specimen positioned in the set-up used for batch annealing process, showing axial discretised region with a plurality of nodes in X and Y direction, in accordance with some embodiments of the present disclosure.

Figure 6a illustrates schematic view of an indication unit showing temperature value of each of the specimens in accordance with some embodiments of the present disclosure.

Figure 6b illustrates graphical representation of core temperature of each specimen during heat treatment process in accordance with some embodiments of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE DISCLOSURE
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, as to its assembly, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

The present disclosure discloses a method and system for real-time monitoring of a heat treatment process include, but is not limited to, batch annealing process. The method and system is configured to provide indication to an operator when specimen reaches a pre-set temperature, so that the operator may perform necessary operations to control heat treatment. Thus, the system and method prevent under or over heat treatment of the specimen.

To overcome one or more limitations stated in the background of the disclosure, the present disclosure provides a system for real-time monitoring of a heat treatment process. The system is configured to monitor the heat treatment process in real-time and also to provide indication to an operator upon reaching pre-set temperatures of the specimen. This reduces under or over heat treatment of the specimen and thereby improve throughput of the plant. The system comprises a control unit interfaced with at least one sensor and associated with a furnace which is used for heat treatment process. The at least one sensor is configured to monitor temperature of fluid flowing in the furnace. In an embodiment, the fluid flows in between inner surface of the furnace and an inner cover provided over specimens for heat treatment. Based on the signal received from the at least one sensor, the control unit detects the temperature of gas flowing in the furnace. The system also comprises a computing unit which is interfaced with the control unit. The computing unit is configured to receive temperature data of the fluid flowing in the furnace from the control unit. Based on the temperature data of the fluid flowing in the furnace, the temperature value of each of the plurality of specimen in the furnace is determined by the computing unit. Further, the computing unit is associated with a memory unit. The memory unit is configured to store one or more data which includes dimensions of each of the plurality of specimens, a plurality of pre-set temperature data, predetermined time intervals of the heat treatment process and the temperature values determined by the computing unit. The memory unit also stores computation required for computing the temperature value of each of the specimen based on the temperature of fluid flowing in the furnace.

The computing unit determines temperature value of each of the plurality of specimens by a predefined technique based on the temperature of fluid flowing in the furnace. In an embodiment, the predefined technique is a numerical analysis technique includes, but is not limited to, Finite difference method, wherein, each of the plurality of specimens is divided into a predefined number of elements and temperature at each element is determined by numerical formulae stored in the memory unit. The temperature values determined by the computing unit are compared periodically with the pre-set temperatures stored in the memory unit. When the temperature value determined by the computing unit reaches one of the pre-set temperatures stored in the memory unit, an indication is provided to an operator via an indication unit associated with the computing unit. The indication provided by the indication unit is at least one of audio means or visual means. The operator after receiving indication from the computing unit operates the heat treatment process accordingly, thereby preventing over or under heat treatment of the specimen. In an embodiment, the heat treatment process is a batch annealing process.

The terms “comprises”, “comprising”, or any other variations thereof used in the specification, are intended to cover a non-exclusive inclusion, such that a system comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.

In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

Figure 1 is an exemplary embodiment of the present disclosure which illustrates a block diagram of the system (100) for real-time monitoring of the heat treatment process. The system (100) is configured to monitor the heat treatment process in real-time, so that under or over heat treatment of specimen is prevented. The system (100) comprises a control unit (1) associated with at least one sensor (6), which is configured to monitor temperature in the furnace (3). In an embodiment, the at least one sensor (6) monitors temperature of the fluid flowing in the furnace (3). In an embodiment, the at least one sensor (6) is selected from group such as but not limiting to thermocouple, pyrometer, thermistor which serves the purpose of monitoring temperature in the furnace (3). The control unit (1) detects temperature value of the fluid flowing in the furnace (3) through the at least one sensor (6). In an embodiment of the disclosure, the control unit (1) includes a processing unit [not shown in figures] for detecting the temperature value, based on input received from the at least one sensor (6).

The system (100) also includes a computing unit (2) interfaced with the control unit (1). In an embodiment of the disclosure, the computing unit may be an external server, and comprises a processing unit and a memory unit. The computing unit (2) is configured to receive the temperature value detected by the control unit (1), and determine temperature of each of plurality of specimens (4) positioned in the furnace (3) during heat treatment [shown in figure 2]. The computing unit (2) includes a processing unit [not shown in figures] for computing temperature value of each of the plurality of specimens (4) by a predefined technique. The processing unit may comprise at least one data processor for executing program components for executing user- or system-generated requests. The processor may include specialized processing units such as integrated system (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc. The processing unit may include a microprocessor, such as AMD Athlon, Duron or Opteron, ARM’s application, embedded or secure processors, IBM PowerPC, Intel’s Core, Itanium, Xeon, Celeron or other line of processors, etc. The processing unit may be implemented using mainframe, distributed processor, multi-core, parallel, grid, or other architectures. Some embodiments may utilize embedded technologies like application-specific integrated circuits (ASICs), digital signal processors (DSPs), Field Programmable Gate Arrays (FPGAs), etc. The processing unit may be disposed in communication with one or more input/output (I/O) devices via I/O interface. The I/O interface may employ communication protocols/methods such as, without limitation, audio, analog, digital, monoaural, RCA, stereo, IEEE-1394, serial bus, universal serial bus (USB), infrared, PS/2, BNC, coaxial, component, composite, digital visual interface (DVI), high-definition multimedia interface (HDMI), RF antennas, S-Video, VGA, IEEE 802.n /b/g/n/x, Bluetooth, cellular (e.g., code-division multiple access (CDMA), high-speed packet access (HSPA+), global system for mobile communications (GSM), long-term evolution (LTE), WiMax, or the like), etc.

Further, the computing unit (2) is associated with a memory unit (7), which is configured to store one or more data. The one or more data includes dimensions of each of the plurality of specimens, a plurality of pre-set temperature data and predetermined time intervals of the heat treatment process. The memory unit (7) also stores the computation formulae required for computation of temperature of each of the plurality of specimens (4). In an embodiment, the memory unit (7) is selected from group such as but not limiting to RAM, ROM …etc. which serves the purpose of storing data. The one or more data stored in the memory unit (7) is recomputed by predefined technique. Therefore, the one or more data stored in the memory unit (7) act as reference points for real-time monitoring of heat treatment process for a given plurality of specimens (4). In an embodiment, the one or more data includes dimensions of each of the plurality of specimens (4), recrystallization temperatures, soaking temperatures, time duration for soaking, time duration for starting furnace cooling, time duration for rapid cooling and total time duration for heat treatment of the plurality of specimens (4). The heat treatment parameters are calculated by analysis tools using numerical methods, based on the dimensions and characteristics of the plurality of specimens (4).

The computing unit (2) receives one or more data from the memory unit (7) for computation of temperature of each of the plurality of specimens (4) by the predefined technique. In an embodiment, the predefined technique is a numerical method. In the numerical analysis, each of the plurality of specimens (4) are discretised in to a predetermined number of elements based on a co-ordinate system and temperature at each element is computed based on the heat transfer condition the element is exposed to. In an embodiment, the co-ordinate system in which each of the plurality of specimens (4) is discretised is at least one of Cartesian co-ordinate system, polar co-ordinate system and cylindrical co-ordinate system. For example, if each of the plurality of specimens (4) is cylindrical in shape the elements are specimen is discretised in to a predefined number of elements based on cylindrical co-ordinate system. During computation of temperature of each of the elements, the temperature of surrounding elements is considered. Thus in numerical analysis, the average temperature of each element is computed.

The computing unit (2) compares the temperature determined for each of the plurality of specimens (4) with the pre-set temperatures stored in the memory unit (7). When the temperature value determined by the computing unit (2) matches with the any one of the pre-set temperatures stored in the memory unit (7), an operator is alerted by an indication unit (6) associated with the computing unit (2). In an embodiment, the operator is alerted when the temperature determined by the computing unit (2) reaches each of the pre-set temperatures of the heat treatment process, thereby enable the operator to monitor and control the heat treatment process. In an embodiment, the indication provided by the indication unit (6) may be at least one of audio means such as but not limiting to alarms, buzzers and visual means such as but not limiting to display interface, color illumination device. In another embodiment, the indication unit (6) provides multiple indications to the operator, as the number of pre-set temperatures and the parameters in a heat treatment process are high. Thus, the indication unit (6) provides multiple indications for the heat treatment process during heating and cooling. Based on the indication received by the operator, the heat treatment process can be controlled, thereby preventing under or over heat treatment of each of the plurality of specimens (4). In an alternative embodiment of the disclosure, the computing unit (2) may be configured to control the process parameters of the heat treatment process based on the indication provided on the indication unit (5).

Figure 2 is an exemplary embodiment of the present disclosure which illustrates a set-up used for carrying out batch annealing process employing the system (100) as described above for real-time monitoring of the batch annealing process. The set-up for batch annealing process includes a base (3d), on which plurality of specimens (4) are stacked one over the other. In an embodiment, the plurality of specimens (4) is cold rolled steel. On the base (3d) an inner cover (3a) is provisioned to seal the plurality of specimens (4) from entry of air or foreign particles. Further, at least one conduit [not shown in figures] is provided in the base (3b) for allowing fluid to flow between the outer surfaces of the plurality of specimens (4) and the inner surface of the inner cover (3a). The set-up also comprises a furnace (3) mounted on the base (3d) over the inner cover (3a). The furnace (3) is configured with provisions for burners (3b) for heating the plurality of specimens (4). In an embodiment, the burners (3b) are selected from group such as but not limiting to gas burners, electric heaters, and the like. In the set-up the plurality of specimens (4) are heated by indirect heat-transfer from heat added by the burners (3b) due to fluid flow in the inner cover (3a). In an embodiment, the burners (3b) are fuelled by fuels such as but not limiting to natural gas, acetylene or any other gas which serves the purpose of heating. The gas fuelling the burners (3b) is maintained in a separate compartment in the heat treatment process, particularly in cylinders. In an embodiment, the fluid is selected from group such as but not limiting to hydrogen, and nitrogen. Further, at least one sensor (6) [temperature sensor] is provided on the base (3d) to monitor temperature of fluid flowing in the inner cover (3a). In an embodiment, the at least one sensor (6) is positioned proximal to the inner cover (3a) for detecting temperature of the fluid flowing in the inner cover (3a). Further, a blower (3c) is configured in the base (3d) to aid flow of fluid in the inner cover (3a).

Before starting the annealing process, the dimensions of each of the plurality of specimens (4) are determined and stored in the memory unit (7) of the system (100). In an embodiment, the dimensions of the plurality of specimens (4) include, but are not limited to, width, length, outer diameter, inner diameter, weight, density. Based on the data collected, temperature and time duration required for annealing of each of the plurality of specimens (4) are calculated by analysis technique such as but not limiting to numerical analysis. Then, a thermal plot is plotted [as shown in figure 3], as a reference to achieve annealing of each of the plurality of specimens (4). As an example, the thermal plot for steel is shown in figure 3. The graph comprises points 1-6, which refers to various phases of heat treatment that must be carried out for batch annealing of the plurality of specimens (4). Points 1-2 refer to heating of the plurality of specimens (4) from room temperature to approximately 700 degrees within a first predetermined time duration. Upon reaching point 2, the temperature is to be maintained at 700 degrees up to a second predetermined time duration to point 3. From point 3, the plurality of specimens (4) is to be furnace cooled to approximately 600 degrees within a third predetermined time duration to reach point 4. From point 4, the plurality of specimens (4) is to be subjected to normal cooling to approximately 400 degrees within a fourth predetermined time duration to reach point 5. From point 5 to 6, the plurality of specimens (4) is then to be cooled rapidly to room temperature within a fifth predetermined time duration. In an embodiment, the first, second, third, fourth and fifth predetermined time durations are in hours.

The following description with reference to figure 4 describes the method for real-time monitoring the heat treatment process particularly, for batch annealing process as described in Figure 2 in one exemplary embodiment.

Figure 4 illustrates a flowchart showing a process involved in heat treatment process, particularly batch annealing process. After starting the heat treatment process, the at least one sensor (6) monitors the temperature of the fluid flowing in the inner cover (3a) at predetermined time intervals, as in step (401). The control unit (1) detects temperature of the fluid flowing in the inner cover (3a), based on the input received from the at least one sensor (5), as in step (402). The temperature detected by the control unit (1) is transmitted to the computing unit (2), as in step (403). The computing unit (2) computes temperature of each of the plurality of specimens (4) by a predefined technique based on temperature of fluid flowing in the inner cover (3), as in step (404).

The predefined technique to determine temperature of each of the plurality of specimens (4) is described as follows, with reference to the exemplary embodiment of the batch annealing process described in figure 2. In an embodiment of the disclosure, finite difference method is used for determine temperature of each of the plurality of specimens (4).

Firstly, each of the plurality of specimens (4) i.e. cold rolled steel is discretised into a predetermined number of elements [as shown in figure 5c]. The discretisation of the plurality of specimens (4) depends on the geometry of the specimen and also the boundary conditions of the specimens i.e. whether the heat flow is steady or unsteady. For the batch annealing process described in figure 2, each of the plurality of specimens (4) is cold rolled steel. The cold rolled steel being cylindrical in shape and symmetrical about its axis, cylindrical co-ordinate system is incorporated for dividing the specimen into elements. Employing cylindrical co-ordinate system will enable to omit angular variations of the specimen and therefore only consider radial and axial dimensions for computations [as shown from figures 5a-5b]. Also, during heat treatment, temperature of the plurality of specimens (4) varies with time. In an embodiment, the temperature variation of the plurality of specimens (4) is due to the changes in heat content of the plurality of specimens (4). Therefore, unsteady state condition is also considered for discretisation. Based on the above pre-requisites, each of the plurality of specimens (4) is discretised [as shown in figure 5c].

Further, heat balancing of each of the elements is carried out, so that temperature at each element is calculated using heat balance equations by numerical analysis. For batch annealing furnace, the heat balancing is done by considering boundary conditions such as but not limiting to specimen outer surface, specimen bore, specimen edges and conduction from exterior surface to interior of the coil Also, as fluid flowing in the inner cover (3a) enables indirect heat transfer from the furnace (3) to the plurality of specimens (4), the fluid too gets heated. At a predetermined temperature, the fluid diffuses thereby improving heat conductivity from fluid to the plurality of specimens (4). Thus, the parameters change in bulk composition of fluid in the free space under the inner cover (3a) and diffusion of fluid into the gaps of the plurality of specimens (4) are also to be considered,

Now, the description in forth coming paragraphs describes an exemplary numerical equations used for determining temperature values of the specimen. In an embodiment, the numerical equations are stored in the processing unit of the system.

Heat balance at Specimen outer bore.
At specimen outer surface, heat is transferred by convection due to fluid flow and also by radiation from inner cover surface to the specimen. Also, the heat is conducted from specimen outer surface to specimen interior of the coil. Thus, at any instance all three parameters stated above must be in equilibrium to achieve heat balance. The same is expressed by the following numerical formulae.

And

Heat balance at inner bore
At inner bore of the specimen (4), the heat is transferred by convection of the fluid flowing in the inner cover (3a). Also, heat is transferred from specimen outer surface to inner bore via conduction. Thus, the heat balance is achieved by following equations:

and

Heat balance at specimen edges
At specimen edges, either the top or bottom edges of the specimen the heat is transferred due to convention. Also, at top edge of the specimen heat is transferred by radiation, therefore, heat balance is achieved by following equations:

and

Conduction from exterior surface to interior of the coil
Heat is transfer from coil outer surface to interior of the coil by conduction, which is governed by Fourier heat transfer equation stated below:

Since this equation can’t be solved analytically, as the material properties like conductivity, density and specific heat capacity varies with temperature. Therefore numerical solution by discretizing the calculation domain is done. The net heat generated inside a cell is

Corresponding temperature rise of the cell is calculated by the following formula

The temperature after time step is given by

Bulk composition of gas under inner cover (3a)
As the fluid flowing in the inner cover is transferring heat from to the plurality of specimens (4), the characteristics of the fluid changes due to heat. Thus, the fluid composition also changes with reference to the characteristics of the fluid. The fluid composition is tracked by below equation:

Diffusion of fluid into gaps of specimen (4)
Fluid, being low in density penetrates or diffuses into the gaps of the plurality of specimens (4). During heat transfer, the fluid also absorbs some quantity of heat. Heat absorption of the fluid increases the temperature, thereby increases the rate of diffusion of fluid. Diffusion of fluid changes its conductivity, which is tracked by the following equation.

Like the heat conduction equation, this also solved numerically. Corresponding discretization equation is

From the above mentioned equations, the temperature of each element is calculated in a sequence. That is, temperature of the elements situated at outer surface of the specimen (4) are first calculated, which is then subsequently calculated for other adjacent elements by corresponding equations. While considering the adjacent elements, the corresponding variation in axial length and radial length from a nodal axis are substituted in the corresponding equation. Based on the substituted values, temperature of each element and consequently of each of the plurality of specimens (4) is determined at predetermined time intervals by the computing unit (2).

Further, the temperature determined by the computing unit (2) is compared with the pre-set temperature stored in the memory unit (7) as in step (405). When the temperature coincides with the temperature stored in the memory unit (7), an indication is provided to the operator.

In an embodiment, multiple indications are provided by the indication unit (5), as there are multiple points in the thermal plot of the batch annealing process [heat treatment process]. Thus, when temperature determined by the computing unit (2) reaches a first predetermined temperature [point 2 in figure 3], a first indication signal is provided by the indication unit (5) as in step (406). Upon receipt of the first indication signal the operator takes necessary actions to proceed with next step in the heat treatment process. As an example, after reaching point 2 [shown in figure 3] the operator soaks the plurality of specimen (4) for a predetermined duration of time. At this stage, the operator controls the burners (3b) and the fluid flow in the inner cover (3a) for soaking the plurality of specimens (4).

The indication unit (5) provides a second indication when the temperature determined by the computing unit (2) reaches a second predetermined temperature [point 3 in figure 3] stored in the memory unit (7) as in step (407). Upon receipt of the second indication signal, the operator takes necessary actions to proceed with next step in the heat treatment process. As an example, after reaching point 3 [shown in figure 3], the system automatically starts cooling process in the furnace to cool the plurality of specimen (4) for a predetermined duration of time. In an embodiment, the operator manually operates the system to control the heat treatment process of the plurality of specimens (4). At this stage, the burners (3b) and the optionally fluid flow in the inner cover (3a) will be stopped for furnace cooling the plurality of specimens (4).

The indication unit (5) provides a third indication when the temperature determined by the computing unit (2) reaches a third predetermined temperature [point 4 in figure 3] stored in the memory unit (7) as in step (408). Upon receipt of the third indication signal, the operator takes necessary actions to proceed with next step in the heat treatment process. As an example, after reaching point 4 [shown in figure 3] the operator cools the plurality of specimen (4) normally for a predetermined duration of time. At this stage, the operator allows air to flow into the furnace for cooling the plurality of specimens (4).

The indication unit (5) provides a fourth indication when the temperature determined by the computing unit (2) reaches a fourth predetermined temperature [point 4 in figure 3] stored in the memory unit (7) as in step (409). Upon receipt of the fourth indication signal, the operator takes necessary actions to proceed with next step in the heat treatment process. As an example, after reaching point 5 [shown in figure 3] the operator cools the plurality of specimen (4) rapidly for a predetermined duration of time. At this stage, the operator forces the air to flow into the furnace for rapid cooling of the plurality of specimens (4).

The indications provided by the indication unit (5) is at least one of audio means such as but not limiting to alarms, and buzzers, and video means such as but not limiting to display interface. In an embodiment, the multiple indications provided by the computing unit (2) can be alternative to audio means or visual means. In an alternate embodiment, the indications can be an audio means with frequency differing for subsequent indications. In another alternate embodiment, the indications can be a video means with color of the indication differing, so that the operator can identify the status of the plurality of specimens (4) [as shown in figure 6a]. For example, the plurality of specimens (4) can be displayed as green during heating, blue during cooling, yellow when the temperature is close to the target and as red when the target temperature has been met.

In another embodiment, the core temperature of the entire batch annealing process can be indicated on the display interface type of indication unit (5) i.e. core temperature values of all the plurality of specimens (4).

In an embodiment, the temperature of each of the plurality of specimens (4) is represented graphically [as shown in figure 6b] on an indication unit (5).

In another embodiment, the indications provided by the indication unit (5) can be different during heating and cooling operations during heat treatment. Thus, based on the indication, the operator can control the heat treatment process of the plurality of specimens (4), and thereby improve throughput of the plant.

In another embodiment, the indications provided by the indication unit (5) can be a numerical value, wherein when the temperature values calculated by the computing unit (2) reaches the pre-set temperature, the value is displayed in the indication unit (5). In another embodiment, the temperature values computed by the computing unit (2) are displayed on the indication unit (5) in each iteration. Thus, the operator gets notified once the temperature computed by the computing unit (5) reaches the pre-set temperature.

Advantages:
The present disclosure provides a system and method for real-time monitoring of heat treatment process of a specimen. This, enables the operator to track the progress of heat treatment of the specimen, and controls the heat treatment parameters. Thereby, prevents over or under heat treatment of the specimen.

The present disclosure provides a real-time monitoring system, which enables the operator to re-initiate the heat treatment process if there was a failure in the plant.

The present disclosure provides a real-time monitoring system, which enables to improve throughput of the system.

Equivalents
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

REFERRAL NUMERALS:
REFERRAL NUMERALS DESCRIPTION
100 System
1 Control unit
2 Computing unit
3 Furnace
3a Inner cover
3b Burners
3c Blower
3d Base
4 Specimens
5 Indication unit
6 Sensor
7 Memory unit
T Temperature
Tsubscript Temperature on left, right, below, center of an element and that of gas
t Time

Time step

Thermal conductivity

Conductivity in radial, axial directions from left to right, right to left, top to bottom, bottom to top

Density
Cp Specific heat capacity
m Mass of the element
R Radial distance from center of the specimen bore to center of the element
R subscript radial distance of the ith element on left, right.
,
distance step in radial and axial directions
ir, ih number of the ith element in radial and axial directions respectively,
nr, nh maximum number of elements in radial and axial directions

emissivity of the coil surface

Stefan Boltzmann constant

heat transfer coefficient between gas and metal
Q heat -generated in a cell, transferred between gas and metal surface

hydrogen fraction of gas under inner cover

hydrogen fraction of gas under inner cover - at time t, at infinite time 8, of the current cell ih, of the cell above ih+1 , of the cell below ih-1
? purge rate of hydrogen
V volume of the free space under the inner cover
D i,j Diffusion coefficient of hydrogen (i) in nitrogen (j)
ni fraction of diffusing gas component

cell length in the direction of diffusion.