Claims:WE CLAIM:
1. A contact heating system (100) for a cylindrical coil shaped object (114), the system (100) comprising:
a plurality of semi-cylindrical heating bodies (106) having sufficient diameter and transverse edges (108), the transverse edges (108) are configured to joined together to substantially cover the cylindrical coil shaped object (114); and
a plurality of pneumatic actuators (110) coupled to the plurality of semi-cylindrical heating bodies (106), the plurality of pneumatic actuators (110) configured to move the plurality of semi-cylindrical heating bodies (106) towards each other such that the transverse edges (108) gets joined to achieve a hollow cylindrical configuration (112) substantially covering the cylindrical coil shaped object (114).
2. The system (100) as claimed in claim 1, wherein each of the semi-cylindrical heating bodies (106) is coupled to the pneumatic actuators (110) by means of a rod (304).
3. The system (100) as claimed in claim 1, wherein each of the semi-cylindrical heating bodies (106) includes a heating element.
4. The system (100) as claimed in claim 1, wherein the plurality of semi-cylindrical heating bodies (106) contacts the cylindrical coil shaped object (114).
5. The system (100) as claimed in claim 4, wherein the heating element is a heating coil.
6. The system (100) as claimed in claim 1, wherein the cylindrical coil shaped object (114) is a cold rolled coil.
7. The system (100) as claimed in claim 1, wherein a plurality of thermocouples is coupled to the plurality of semi-cylindrical heating bodies (106) and the cylindrical coil shaped object (114).
8. The system (100) as claimed in claim 7, wherein a data recorder (802) is coupled to the thermocouples deployed on to the plurality of semi-cylindrical heating bodies (106) and the cylindrical coil shaped object (114).
9. The system (100) as claimed in claim 7, wherein a controller is coupled to the thermocouples deployed on to the plurality of semi-cylindrical heating bodies (106) and the cylindrical coil shaped object (114).
10. The system (100) as claimed in claim 1, wherein the semi-cylindrical heating bodies (106) includes ceramic fibre insulation.
11. The system (100) as claimed in claim 1, wherein the system (100) is provided in a box type enclosure (102).
, Description:CONTACT HEATING SYSTEM FOR A CYLINDRICAL COIL SHAPED OBJECT
FIELD OF INVENTION
[001] The present invention relates to the contact heating of a cylindrical shaped coil or annular cylinder by means of direct contact elements from its surface. Particularly, the present invention relates to a system for heating cold rolled coil metal sheets by direct contact.

BACKGROUND OF THE INVENTION

[002] The research community is engaged in its continuous pursuit for easier and faster transfer of heat transfer. Despite all efforts by research, industrial application of heat transfer cannot find alternative means of heat transfer from the conventional burners or firing System in boilers, furnace used in Industries. Heating and cooling is the most extensive operations out of other operations involved in the industries. Out of alternative means, a group of scientists already have done work in the areas of contact heat transfer. It is nothing new since the human beings learnt the origin of fire from the rubbing of stones and from the early days of civilization, primitive means of research have already been done by mankind through trial and error processes.

[003] Apart from cooling, the other important process in any process is the heating the material or the stock. In industrial application, batch annealing furnace is used for annealing process in cold rolling mill of a Steel plant. Annealing is done to stress relieve the cold rolled sheets through the mechanism of recovery, recrystallization and grain growth. Annealing of cold rolled sheets is performed either in a tunnel type continuous annealing furnace or in a batch annealing furnace. In the batch annealing furnace, the cold rolled sheets are coiled and coils are placed in the form of a stack for annealing Operation in a cylindrical furnace stacked e Most of the time, gas fire heaters. In this process of the annealing is 3-4 cylindrical Steel coils are stacked on a furnace base and annealed in a hydrogen atmosphere. Alternative means of this heating for annealing is another area of search by the research community for the heat transfer a cylindrical body. Apart from convection and radiation, people also take the help of conduction depending on the circumstance. Hence, contact heat transfer is still another area of pursuit.

[004] Existing literature have shown past experimental work involving the contact heating between two metals or two bodies. Most of the existing literature have encompassed the sliding of two surface when one of them is fixed and the other one is sliding or with the application of a pressure in between them.

OBJECTIVE

[005] The prime objective of the present invention is to provide a heating method of annular shaped coil or a hollow cylinder shaped body by direct contact of another body. The main objective of this invention is the heat transfer by a relatively faster rate of heat transfer and reduction of heat loss during heat transfer by conduction during direct contact. It is also the objective of this invention to investigate the retention mechanism of the heat by the annular cylindrical shaped Cold rolled coil through this process of heat transfer. This novel System has been conceived with a view to adopt in heating annular shaped body. This also fulfills the objective of preheating a hollow cylinder shaped body with the help of already heated two semi-cylindrical bodies by direct contact.

[006] Another object of the invention is to propose a System made of combination of high insulating materials for maximum heat transfer to the subject material/hollow cylinder shaped body.
SUMMARY OF THE INVENTION

[007] The present disclosure relates to a contact heating system (100) for a cylindrical coil shaped object (114), the system (100) includes a plurality of semi-cylindrical heating bodies (106) having sufficient diameter and transverse edges (108), the transverse edges (108) are configured to joined together to substantially cover the cylindrical coil shaped object (114); and a plurality of pneumatic actuators (110) coupled to the plurality of semi-cylindrical heating bodies (106), the plurality of pneumatic actuators (110) configured to move the plurality of semi-cylindrical heating bodies (106) towards each other such that the transverse edges (108) gets joined to achieve a hollow cylindrical configuration (112) substantially covering the cylindrical coil shaped object (114).

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[008] Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings of the exemplary embodiments and wherein:
Figs. 1a and 1b: perspective views of a contact heating system of a cylindrical coil shaped object in accordance with an embodiment of the present disclosure
Fig 2: Cold Rolled (CR) coil
Fig 3: hollow cylindrical configuration achieved through the plurality of semi-cylindrical bodies
Fig 4: schematic view of the contact heating system of Fig. 1 illustrating various components
Fig 5: a schematic view of the hollow cylindrical configuration with the cylindrical object
Fig. 6: Contact heating System without lid
Fig. 7: Contact heating System with the lid and insulation
Fig. 8: Complete experimental set up along with the data recorder
Fig. 9: Comparison of rise of temperature profile with time for CR roll and semi-cylindrical bodies

[009] The figure(s) depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily 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 PREFERRED EMBODIMENTS OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

[0010] The present invention, now be described more specifically with reference to the following specification.

[0011] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that 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 subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.

[0012] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.

[0013] Figs. 1a and 1b illustrates perspective views of a contact heating system 100 of a cylindrical coil shaped object in accordance with an embodiment of the present disclosure. The contact heating system 100 includes an insulating box or enclosure 102. The enclosure 102 is substantially cubical defining an opening 104. In an embodiment, the enclosure 102 includes a plurality of semi-cylindrical bodies 106 defining a plurality of transverse edges 108, the plurality of semi-cylindrical bodies 106 includes heating elements. In an example, the enclosure 102 may be made of metallic, asbestos, etc. type of material.

[0014] In an example, the plurality of semi-cylindrical bodies 106 are coupled to a plurality of pneumatic actuators 110 such that the semi-cylindrical bodies 106 can be moved towards each other and retracted away from each other under action of the pneumatic actuators 110. Further, the plurality of transverse edges 108 of the plurality of semi-cylindrical bodies 106 contact each other when the plurality of semi-cylindrical bodies 106 are moved towards each other under action of the pneumatic actuators 110 to achieve a hollow cylindrical configuration 112. Alternatively, the enclosure 102 may house a plurality of quarter-cylindrical bodies configured to achieve a hollow cylindrical configuration 112, under action of the pneumatic actuators 110. In an example, operation of the pneumatic actuators 110 may be manual, semi-automatic, or automatic.

[0015] In an embodiment, the hollow cylindrical configuration 112 is configured to receive a cylindrical object 114 for dry contact heating through the heating elements embedded in the plurality of semi-cylindrical bodies 106. In an example as shown in Fig. 2, the cylindrical object 114 is a cold rolled (CR) sheet in a cylindrical configuration. In an example, the CR sheet is 0.7 mm to 1.0 mm in thickness, 100 mm long, and is coil shaped (with three turns) of diameter 50 m.

[0016] Fig. 3 illustrates the hollow cylindrical configuration 112 achieved through the plurality of semi-cylindrical bodies 106. The plurality of semi-cylindrical bodies 106 are provided with the heating elements so as to get them heated to a desired temperature. In an example, the maximum working temperature associated with the contact heating system 100 is around 250 Degree Celsius.

[0017] Fig.4 illustrates a schematic view of the contact heating system 100 of Fig. 1 illustrating various components. As shown the plurality of semi-cylindrical bodies 106 are coupled with the pneumatic actuators 110 through rods 304, so that the rods 304 can be made to be moved in axial direction for achieving movement of the plurality of semi-cylindrical bodies 106 towards and away from each other. As shown, the rods 304 are fixed on walls 306 of the enclosure 102, the walls 304 being opposite to each other. In an example, the walls 306 include an intervening medium substantially between a thickness of the walls 306, the thickness being defined between an inner casing and an outer casing of the enclosure 102. The intervening medium is designed so as to minimize heat loss to the outside environment and outside ambient does not become hot while the semi-cylindrical bodies 106 are heated inside the enclosure 102.

[0018] As mentioned earlier, the plurality of semi-cylindrical bodies 106 are moved towards each other under action of the pneumatic actuators 110 to achieve the hollow cylindrical configuration 112, wherein the hollow cylindrical configuration 112 is configured to receive the cylindrical object 114 for dry contact heating through the heating elements embedded in the plurality of semi-cylindrical bodies 106. Fig. 5 shows a schematic view of the hollow cylindrical configuration 112 with the cylindrical object 114. In an example, distance between the plurality of semi-cylindrical bodies 106 and the cylindrical object 114 may be varied so as to transfer a varying degree of heat. In an example, a gap may be maintained between the plurality of semi-cylindrical bodies 106 and the cylindrical object 114.

[0019] Further, K-type thermocouples are drilled on four different locations of the semi-cylindrical heating bodies 106. Each thermocouple has been located at the midpoint of the length of each 100 mm of the semi-cylindrical heating body 106. Two thermocouples are located radially opposite to each other when the two semi-cylindrical bodies 106 are in clubbed or closed position to achieve the hollow cylindrical configuration 112. Other two thermocouples are located at a position almost at right angle to the previously mentioned thermocouples on the periphery of the semi-cylindrical heating bodies 106. Close to the position of each thermocouple on the semi-cylindrical bodies 106, another thermocouple is located on the CR coil (the cylindrical object 114). Hence, there are four thermocouples on the semi-cylindrical heating bodies 106 and four thermocouples on the CR Coil 114 located centrally in the box type enclosure 102.

[0020] When a top lid of the enclosure 102 is taken out, the two semi-cylindrical heating bodies 106 (capable of moving) fitted with heating coils and thermocouples, and the fixed CR coil 114 (fitted with thermocouples) can be seen from the top, as illustrated in Fig. 6. The above contact heating system 100 with insulation and the lid is shown in Fig. 7. The box enclosure 102 shown in Fig. 7 is thermally insulated from the outside ambient conditions. A hollow portion (the opening 104) between the inner casing and the outer casing enables the enclosure 102 to maintain a level of minimum heat loss.

[0021] The leads of the thermocouples from the two semi-cylindrical heating bodies 106 and the fixed CR coil 114 are taken out to connect to a data recorder 802 or a data acquisition System 802. In an example, a Yokagowa make data recorder with 20 channels, as shown in Figure 8, serves the purpose of the data acquisition system 802. Fig. 8 depicts the contact heating system 100 along with the data recorder 802. The data recorder 802 monitors the temperature of the semi-cylindrical heating bodies 106 and the fixed CR coil 114 from the temperature readings of thermocouples. The temperature values are displayed on the data recorder 802 and the values get updated after every 10 seconds. A 20-channel data recorder from YOKOGAWA make (Model number DX2020-3-4-2) has been used for this purpose. Recording frequency of thermocouple data can be set at 10 seconds or at higher interval of one minute. For the present cases of tests, it has been set to 10 seconds. These temperatures are recorded after every 10 seconds from reading of thermocouples as displayed by the reading of 18 channels. The whole box enclosure 102 and the data recorder 802 have been placed on different tiers or platforms of a trolley. A switch board to operate the heater, ON or Off, is also mounted on one side of the trolley.

[0022] A Controller has been fitted to track the temperature of the semi-cylindrical heating bodies 106 with a tolerance of 5 degree C that triggers the Circuit to make the power of heating off when the temperature is either above or below a preset temperature. Hence, there is a maximum Variation of 5 degree C. The Controller temperature has been set to a preset temperature of 200 Degree C at the beginning of the test. Once the heater is turned “ON” by means of the switch from the switch board, the temperature of the semi-cylindrical heating bodies 106 is noticed to be increasing with the time and accordingly the temperature reaches up to the set temperature. Heat can be transferred to the fixed CR coil 114 by direct contact when the moving semi-cylindrical heating bodies 106 are brought in direct contact with the fixed CR coil 114. The temperature of the fixed CR coil 114 increase with time when it is brought in contact with the semi-cylindrical heating bodies 106, and correspondingly, temperature of the semi-cylindrical heating bodies 106 fall with time. In the later phase of present tests, the heating circuit was maintained to be “ON” even after the semi-cylindrical heating bodies 106 touch the fixed CR coil 114 and remain in that position. The Controller has been set such that the temperature of the semi-cylindrical heating bodies 106 can maintain a tolerance of 5 Degree Celsius either above or below the set temperature of 200 Degree Celsius. In an example, the Controller is configured to control the operating sequence of the heating coils of the semi-cylindrical bodies 106. The Controller may be provided along with a regulating device connected to the semi-cylindrical heating bodies 106. The regulating device include a sensor, viz. Thermocouple, disposed at the inner circumference of the semi-cylindrical heating bodies 106 for sensing the temperature of the inner surface of the heating bodies 106 wherein the said thermostatic control and regulating device maintains a temperature Variation of +/- 5 Degree Celsius from the set temperature. The Controlling device turns off the heater connected to the semi-cylindrical bodies 106 once the temperature is reached within the above mentioned range from the set temperature.

[0023] The contact heating system 100 deals with the direct raise of temperature of the semi-cylindrical heating bodies 106 up to 200 Degree C and its effect has been shown in Fig. 9. When the semi-cylindrical heating bodies 106 are heated to a temperature of 200 degree C, they are brought to touch the centrally located CR coil 114 in direct contact. Once they touch the CR coil 114, they are kept in that position. This is continued until the CR coil 114 temperature is very close to it. As can be found from the same Figure 9, the temperature increase curve for all thermocouples connected to the CR coil 114 are more or less smooth than more zigzags. The temperature trend shows the monotonically increasing behavior. In other words, the CR coil 114 has received heat by direct contact. It is worth noting that the temperature gain or the temperature up to which the CR coil 114 or a annular cylindrical coil can be raised by direct contact is completely dependent on the final temperature of the semi-cylindrical heating bodies 102 up to which they have been raised by heating. On the other hand, it is the transfer property or mainly thermal conductivity of the test plate (the CR coil 114 in this case) to transfer the rate of heat transfer during direct contact by the fixed plate.

[0024] In operation, a working of the contact heating system 100 may be explained as following. Firstly, placing the two semi-cylindrical bodies 106 used for heating purpose (or heating plates) and the fixed cold-rolled (CR) coil 114 or cylindrical annular shaped pipe with three turns inside the box-type enclosure 102. The enclosure 102 has been fabricated so as to have the minimum possible amount of leakage of heat to outside ambient. Next, fitting heating arrangement on the two semi-cylindrical bodies 106 with heating elements. The two semi-cylindrical bodies 106 with heating arrangement are equipped with the facility of movement in axial direction, while the cold rolled coil 114 is stationary in the central position of the box 102. A pneumatic operated control mechanism (the pneumatic actuators 110) has been designed and fixed to the two opposite ends of the rectangular walls 306 of the box 102. This control System, connected to the rod 304 at each end that in turn holds each of the semi-cylindrical body 106 with heating element and this control System simulates the axial movement of the semi-cylindrical bodies 106 in radially opposite direction.

[0025] An arrangement for thermal insulation of the box type enclosure 102 is provided, so that there is minimum dissipation of heat from the inside environment of the box type enclosure 102 to the ambient. The arrangement has been made for the thermal insulation of the box 102 type System that contains the cylindrical heating arrangement (semi-cylindrical heating bodies 106) and the fixed CR coil 114. The System of the enclosure 102 has been properly insulated apart from the cover at the top of the box type enclosure 102. This minimizes the heat loss to the surroundings from the heated fixed Steel plate (test plate) and two moving copper plates. Use of the semi-cylindrical bodies 106 fitted with heating elements for quicker heating and cold-rolled Steel coil 114 as the material for the fixed object. Next, heating arrangement mounted on the two semi-cylindrical bodies 106. Next, fixing thermocouples on the two moving semi cylindrical bodies 106 and the fixed cylindrical CR coil 114 in the middle.

[0026] Next, heating of the two semi-cylindrical bodies 106 to a higher temperature than the environmental temperature and recording of the temperature by means of thermocouples throughout the period of heating. Once heated to a higher temperature, the two semi-cylindrical bodies 106 are brought close to the fixed CR coil 114 and kept in direct contact with the CR coil 114. Next, heating the two semi-cylindrical bodies 106 up to 200 degree C, followed by direct contact for 5 minutes with the centrally located CR coil 114. Next, recording of thermocouple temperature from the fixed CR coil 114 or the cylindrical annular body as well as from the moving semi-cylindrical bodies 106 during heat transfer and this data capturing continues till all bodies (two semi-cylindrical bodies 106) and the fixed cylindrical CR coil 114 or the annular shaped cylindrical body reach an equilibrium temperature. This ensures the attainment of the steady state condition.

[0027] It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims.