Title of Invention

A DEVICE FOR ONLINE MEASUREMENT OF TEMPERATE OF COKE OVEN WALL SKIN

Abstract A thermocouple device for on-line measurement of temperature of coke oven wall skins having a L-shaped thermocouple which is In contact with the oven wall skin during use and is held firmly in the position by a support which is a moveable arm which when actuated presses the thermocouple against the oven wall the maintain the thermocouple in a desired position. The thermocouple is provided inside a housing made of a stainless steel sheath. The movement of the moveable arm is remotely controlled by wires fitted to the arm.
Full Text The present invention relates to a device for on-line measurement of temperature of coke oven wall skin. More particularly, the invention relates to a device for on-line direct measurement of temperature of the coal side oven wall and for indicating continuous temperature measurements for the whole coking period.
A coke oven battery consists of about 65-78 ovens and an equal number of heating walls arranged alternately. Each heating wall has 28-30 vertical flues (where gas burners are installed). Conventionally temperature condition at the base of burner brick is measured with hand-held optical pyrometer from inspection ports of vertical flues. This gives temperature condition of hotter side of oven wall.
The temperature of the oven wall in contact with the moist coal charge (colder side) is also an important criterion for ensuring higher life of the oven wall. There does not exist any device for measuring temperature condition of oven wall which is in contact with moist coal charge (colder side). Before the ovens are charged, through the charging holes located at the oven top, the doors of the ovens are closed. Hence oven walls are not accessible for temperature measurement by pyrometer.
The object of the present invention is, therefore, to provide a device for on-line measurement of temperature of coke oven wall skin so as to ensure higher life of the oven by preventing damage to the oven walls and to reduce repair and maintenance costs.
A further object of the invention is to provide a device for on-line measurement of temperature of coke oven wall skin which is inexpensive and reliable.
Thus the present invention relates to a device for on-line measurement of temperature of coke oven wall skin comprising'
a thermocouple adapted to contact the oven wall;
means for engaging the thermocouple firmly against the oven wall.
The thermocouple is L-shaped and the horizontal end of the thermocouple, during use is in contact with the oven wall. The thermocouple is provided inside a housing.. The housing may be a stainless steel sheath or other suitable material.
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The means for engaging the thermocouple is a moveable arm which presses the thermocouple against the oven wall and maintains the thermocouple in a desired position. According to a preferred embodiment the engaging means is an arm pivoted to the housing of the thermocouple. The arm is moveably activated remotely by activating means.' According to a preferred aspect the arm is hinged to the housing and is activated by one or more heat resistant wires. The arm is hinged to the housing in a manner such that when the arm is in horizontal position, it forms a substantial straight line with the horizontal end of the thermocouple so that when the arm is pressed against the oven wall the horizontal end of the thermocouple is also pressed against the oven wall at a substantially diametrically opposite end. The movement of the arm is controlled remotely by one or more wires. When the arm is moved away from the horizontal position the thermocouple is disengaged from the oven wall
The means for engaging the thermocouple to the oven wall may have a different construction.
The thermocouple tip projects out of the horizontal limits of the L-shaped housing and is in contact with the oven wall. According to a preferred aspect, the thermocouple is a chromel-alumel thermocouple.
For a better understanding of the invention, the device according to the invention will be illustrated with the help of a specific embodiment of the invention shown in the accompanying drawings, in which
Fig. 1 shows a sectional view of a general arrangement of ovens and heating walls ;
Fig. 2 shows the thermocouple device according to the invention.
The basic arrangement of ovens, 1 and heating walls 2 in a coke oven battery is shown in Fig. 1. The ovens and heating walls 2 are arranged alternately. The thermocouple device 3 of the invention is inserted from the oven top through the charging hole.
In,Fig. 2 the thermocouple device 3 is shown in greater details. The thermocouple 3 is L-shaped and horizontal link 4. The thermocouple is housed in a stainless steel tube 5. Inside the tube ceramic beads 6 are provided for insulation. The
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thermocouple 3 has head 7 and tip 8. The tip 8 comes into contact with the wall skin and provides on-line temperature information.
Close to the elbow portion 10 of the L-shaped thermocouple 3 a member 11 projects. A moveable arm 12 is hingedly fixed to the member 11. Two hook members 13 and are provided on the said arm 12 and heat resistant wires 14 and
15 and are engaged to the said hooks. The wires 14 and 15 and extend outside the oven so as to be activated to move the arm 12 up and down along the hinge. When the wires are released, the arm 12 drops by gravitation and hangs vertically from the hinge. The wires 14 and 15 and are guided through a plurality of hooks
16 provided on the steel casing.
The thermocouple 3 is inserted into the oven with the arm 12 hanging vertically down. When the device 13 has been brought to the desired position the wire 14 is pulled and the arm 12 moves up. The arm 12 is pulled and it gets engaged to the wall skin by frictional engagement. During the engagement to horizontal link 4 of the device on the diametrically opposite end of the arm 12 gets engaged frictionally to the wall skin of the oven. The tip 8 of the thermocouple is in contact with the oven wall. The tip 8 projects out by about 1-2 mm from the steel casing and measures the temperature of the wall.
The dimension of the L-shaped device has to be designed depending upon the particular battery design in which it would be used.
In order to disengage the device the wire 15 is pulled and the arm 12 and the device as a whole get disengaged from the walls.
The device according to the inventor has been found to be extremely useful in monitoring the coal side temperature of the heating wall. Generally temperature of oven wall drops down to 700-800°C from a level of 1100°C as soon as the oven is charged with cold blend. As it is apprehended that the skin temperature of oven wall (from coal side) may go below 571°C (which is critical for Silica bricks), at least for sometime after charging.
Continuous temperature measurements were taken using the device of the invention for the whole cooking period in a conventional coke oven and! a temperature mapping of free space and oven wall.
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TEMPERATURE MAPPING OF FREE SPACE &. OVEN WALL

Time elapsed after charging
Free Space Temperature
Oven Wall Temperature
(Before Charging)
850
1100
15 minutes
750
800
60 minutes
720
720
120 minutes
680
700
180 minutes
680
700
240 minutes
680
750
300 minutes
690
725
360 minutes
700
730
420 minutes

00
750
480 minutes
700
800
540 minutes
710
825
600 minutes
710 ,
850
660 minutes
720
900
720 minutes
730
950
780 minutes
790
950
840 minutes
740
1000
900 minutes
740
1000
960 minutes
750
1050
1020 minutes
770
1100
1080 minutes
780
1100
With cross flow of raw gas across oven free space
15 minutes 730
675
60 minutes
695
605
120 minutes
690
540
150 minutes
675
540
180 minutes
675
540
240 minutes
670
545
300 minutes
680
545
360 minutes
690
550
420 minutes
690
565
480 minutes
700
590
540 minutes
700
625
600 minutes
710
650
660 minutes
710
720
720 minutes
720
800
780 minutes
730
870
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The table shows that with the cross flow of raw gas across oven free space the temperature of the wall skin goes down below the critical temperature of 571°C. The direct measurement of the skin wall temperature help ' to detect the temperature accurate on-line and corrective steps may be taken to maintain the temperature at above the critical temperature so that the silica bricks do not degrade and reduce the life of the walls'.
The major advantages of the device of the invention are :
1) Direct and on line measurement of the coal side wall of the oven.
2) Continuous temperature change is monitored during the whole cooking period.
3) The temperature record has High degree of accuracy.
4) The device is inexpensive and can be fabricated.
5) The continuous monitoring of the wall skin prevent wall damage and improve the life of oven.
6) There is substantial saving in repair and maintenance cost.
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WE CLAIM :
1. A device for on-line measurement of temperature of coke oven wall skins
comprising
a housing
a thermocouple provided inside the housing and engaged in contact with the oven wall skin, said thermocouple being L-shaped and the horizontal end of the thermocouple adapted to be in contact with the oven wall in use ; and
a moveable arm pivoted to the housing of the thermocouple, said moveable arm when actuated presses the thermocouple against the oven wall and maintains the thermocouple in a desired position in contact with the oven wall skin.
2. A device as claimed in claim 1, wherein the thermocouple is L-shaped and the horizontal end of the thermocouple being adapted to be in contact with the oven wall in use.
3. A device as claimed in claim 1 wherein the housing is made of a stainless steel sheath.
4. A device as claimed in claim 4 wherein one or more heat resistant wires are connected to the arm move the arm and move the thermocouple to the desired portion.
5. A device as claimed in claims 4 or 5 wherein the arm is hinged to the housing.
6 A device as claimed in anyone of preceding claims, wherein the thermocouple is a chromel-alumel thermocouple.


Dated this 2nd day of March 2000

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A thermocouple device for on-line measurement of temperature of coke oven wall skins having a L-shaped thermocouple which is In contact with the oven wall skin during use and is held firmly in the position by a support which is a moveable arm which when actuated presses the thermocouple against the oven wall the maintain the thermocouple in a desired position. The thermocouple is provided inside a housing made of a stainless steel sheath. The movement of the moveable arm is remotely controlled by wires fitted to the arm.

Documents:

00126-cal-2000-abstract.pdf

00126-cal-2000-claims.pdf

00126-cal-2000-correspondence.pdf

00126-cal-2000-description(complete).pdf

00126-cal-2000-drawings.pdf

00126-cal-2000-form-1.pdf

00126-cal-2000-form-18.pdf

00126-cal-2000-form-2.pdf

00126-cal-2000-form-3.pdf

00126-cal-2000-p.a.pdf

126-cal-2000-granted-abstract.pdf

126-cal-2000-granted-claims.pdf

126-cal-2000-granted-correspondence.pdf

126-cal-2000-granted-description (complete).pdf

126-cal-2000-granted-drawings.pdf

126-cal-2000-granted-examination report.pdf

126-cal-2000-granted-form 1.pdf

126-cal-2000-granted-form 18.pdf

126-cal-2000-granted-form 2.pdf

126-cal-2000-granted-form 3.pdf

126-cal-2000-granted-letter patent.pdf

126-cal-2000-granted-pa.pdf

126-cal-2000-granted-reply to examination report.pdf

126-cal-2000-granted-specification.pdf


Patent Number 195415
Indian Patent Application Number 126/CAL/2000
PG Journal Number 30/2009
Publication Date 24-Jul-2009
Grant Date 11-Nov-2005
Date of Filing 02-Mar-2000
Name of Patentee STEEL AUTHORITY OF INDIA LIMITED
Applicant Address ISPAT BHAWAN, LODI ROAD
Inventors:
# Inventor's Name Inventor's Address
1 SHYAM SUNDAR BANDYOPADHYAY RESEARCH AND DEVELOPMENT CENTRE FOR IRON AND STEEL, STEEL AUTHORITY OF INDIA LTD., DORANDA, RANCHI - 834 002
2 TILAKRAJ BHASKARRAO CHAHANDE RESEARCH AND DEVELOPMENT CENTRE FOR IRON AND STEEL, STEEL AUTHORITY OF INDIA LTD., DORANDA, RANCHI - 834 002
3 BASUDEV CHAKRABORTY RESEARCH AND DEVELOPMENT CENTRE FOR IRON AND STEEL, STEEL AUTHORITY OF INDIA LTD., DORANDA, RANCHI - 834 002
4 PARTHASARTHY LAKSHMANAN RESEARCH AND DEVELOPMENT CENTRE FOR IRON AND STEEL, STEEL AUTHORITY OF INDIA LTD., DORANDA, RANCHI - 834 002
5 NIRMAL KUMAR GHOSH RESEARCH AND DEVELOPMENT CENTRE FOR IRON AND STEEL, STEEL AUTHORITY OF INDIA LTD., DORANDA, RANCHI - 834 002
PCT International Classification Number G05D 23/22
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA