FIELD OF THE INVENTION
The disclosure relates to iron making. Particularly the disclosure relates to efficiently heating and thereby melting chilled metal andslag inside hearth.
BACKGROUND OF THE INVENTION
Blast furnaces in an iron and steel industry are used for smelting of iron from iron ore. The operations of the blast furnaces have undergone significant improvements, particularly over the past thirty years, in terms of quality of raw material feed, operating practice as well as equipment and facility. In the pre-liberalization era, focus of improvement was more on raw materials and operating practice whereas in the post liberalization era the focus shifted more on improvement in operating practice.
To start blast furnace starting up after long shutdown is always a herculean task. This involves multiple man machine interfaces which is very risky, and adds up to the overall workflow. Conventionally, in blast furnaces lancing is done manually. A group of people used to hold lancing pipe and channel oxygen into the hearth/ tuyere area of the blast furnace. This process has to be done till connectivity is ascertained between tap hole and tuyere. The connectivity is term used to the establishment of communication between tuyere and taphole which had choked initially due to frozen metal.
This process is a hard, long, hazardous with relatively little heat and has the risk of further cooling down of furnace. This is used for semi chilled furnace when the chemical energy stored inside the furnace is less. Sometime this process used to go upto for 4 days.
OBJECTS OF THE INVENTIONS
In view of the foregoing limitations inherent in the prior-art, the object of the disclosure is to design an oxylance for heating hearth through tap hole.
The other object of the disclosure is to design an Oxylancein which low risk is involved while lancing.

The further object of the disclosure is to design an Oxylance which requires minimal manual effort.
Still further object of the disclosure is to design an Oxylance which gives cost benefit.
Still further object of the disclosure is to design an Oxylance which ensures workplace safety.
SUMMARY OF THE INVENTION
In variousaspects, the disclosure providesa quick revival of furnace along with improving workplace safety.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING:
Fig. 1 shows an Oxylancefor heating inside of hearth through tap hole in accordance with various embodiments of the disclosure.
Fig. 2 shows a picture ofthe Oxylance for heating inside of hearth in accordance with one embodiment of the disclosure.
DETAILED DESCRIPTION OF THE INVENTION
Various embodiments of the disclosure provide an oxylance for heating hearth through tap holecomprisinga long pipe being configured to channel oxygen and compressed air for heating and thereby melting chilled metal andslag inside hearth;the long pipe positions at least two thermocouplesall arranged sequentially maintaining distance from each other, starting from a first thermocouple to a last thermocouple, the first thermocouple is positioned at or close to tip of the long pipe, all the thermocouples are coupled to controller where the thermocouple data are continuously monitored and recorded; andthe long pipe being inserted in hearth upto a position where the last thermocouple is inside hearth, leaving tap hole refractory region, so that the last thermocouple when about to be damaged or connectivity between tuyere and tap hole

is established, whichever being attained first due to heat dissemination, and pulling out the Oxylance.
Shown in FIG. 1 is an oxylance (100) to be inserted in hearth through tap hole for heating chilled metal and slag inside hearthof blast furnace. The oxylance (100) comprises a long pipe (104) to be inserted in the hearth.
The long pipe is configured to channel oxygen in the hearth at high pressure. For this the long pipe (104) is coupled with a hose of oxygen pipe (not shown in the figure). To support the melting of chilled metal and slag inside hearth, the long pipe (104) is further coupled with atleast one hollow pipe (112a, 112b). This hollow pipe (112a, 112b) is being configured to channel compressed air further to the long pipefor efficient melting of chilled metal and slag inside hearth. The hollow pipe is connected with hose pipe of compressed air pipe.
In accordance with other embodiments of the disclosure more than one hollow pipemay be employed to optimize the melt rate of chilled metal and slag inside hearth.
The long pipe is made up of cast steel or stainless steel.
The long pipe (104) comprises at least two thermocouples (108a, 108b) all arranged sequentially maintaining distance from each otherstarting from a first thermocouple (108a) to a last thermocouple (108b). The thermocouples are separated by some distance to give fair temperature readingat various points inside the hearth.
For the sake brevity only two thermocouples have been defined here namely a first thermocouple (108a) and a last thermocouple (108b). Whereas while reducing into practise more than one thermocouple such as 2 or 3 or 4 or 5 or may be more can be used. All the thermocouples are separated by distance to determine the temperature inside the hearth at points of interest.
The long pipe (104) continuously pumps oxygen into the hearth so as togenerate exothermic reaction. This exothermic reaction produces such heat that the temperature

becomes inside the hearth becomes very high thereby melting chilled metal andslag. This temperature inside hearth needs to be monitored.
To monitor the temperature rise inside the hearth, all the thermocouples are coupled with a controller (not shown in fig). The controller thermocouple data are continuously monitored and recordedgiving real time temperature inside the hearth.
The first thermocouple (108a) is positioned at or near the tip of the long pipe. Due to continuous rise in temperature the first thermocouple (108a) gets damaged first. At the same time due to continuous pump of oxygen inside the hearth, the temperature rises.This rise in temperature starts disseminating, thereby heating the surrounding as well.
Once the temperature inside the hearth reaches beyond the measurable limit of the first thermocouple, its gets damaged. The temperature inside of the hearth can reach upto 1300 deg. C. The maximum temperature which the first and last thermocouple can measure is 1500 deg. C.
So as soon as the first thermocouple gets damaged the controller notices the temperature. At this juncture the controller also notifies to the operator by some means that the first thermocouple has got damaged and the operator becomes cautious. Cautiousness is important because now the operator has fair amount of idea about how much is the temperature inside.
Post the damage of the first thermocouple, dissemination of the heat in the hearth reaches to the last thermocouple (108b). Now the last thermocouple (108b) also starts witnessing the rise in the temperature in the hearth. This rise in temperature shall now be cautiously monitored by the operator and connectivity between tuyere and tap hole is looked for. Once the connectivity is established, the operator can pull out the long tube (104).

The operator needs to look whether the last thermocouple is about to get damaged or connectivity between tuyere and taphole is establisheddue to heat dissemination.Whicheverbeing attained first, the operator can pull out the Oxylance.
In case three thermocouples are used, after the first thermocouple gets damaged, the operator will be notified and the temperature will be noted. The second thermocouple will now be monitored and as it gets damaged the again the operator will be notified and the temperature will be noted. Now the operator may become cautious about the rise of the temperature and reaching looks for connectivity. As soon as the connectivity is established the operator can pull out the Oxylance.
The long pipe is coated with refractory material to provide it heat resistance. It would be appreciated to note that the long pipe is inserted in hearth upto a position where the last thermocouple is inside hearth, leaving tap hole refractory region. This ensures the last thermocouple is inside the hearth and the oxygen sprayed in the hearth is almost 100% utilized.
In accordance with other embodiment of the disclosure the long pipe can be separated by means of a flange (116) in between, having one part of a length and other part with provisions of the hollow pipe.
Fig. 2 shows a picture ofthe Oxylance for heating inside of hearth in accordance with one embodiment of the disclosure.
Advantages:
Almost 100 % utilization of Oxygen. Low risk is involved while lancing. Requires minimal manual effort. Cost benefit. Ensures workplace safety.

WE CLAIM
1. An oxylance(100) for heating hearth through tap hole, the oxylance(100) comprising:
a long pipe (104)being configured to channel oxygen and compressed air for heating and thereby melting chilled metal andslag inside hearth;
the long pipe (104) positions at least two thermocouples(108a, 108b)all arranged sequentially maintaining distance from each other, starting from a first thermocouple to a last thermocouple, thefirst thermocouple is positioned ator close to tip of the long pipe (104), all the thermocouplesare coupled to controller where the thermocouple data are continuously monitored and recorded; and
the long pipe (104) being inserted in hearthupto a position where the last thermocouple is inside hearth,leaving tap hole refractory region, so that the last thermocouplewhen about to be damaged or connectivity between tuyere and tap hole is established, whichever being attained firstdue to heat dissemination, and pullingout the Oxylance.
2. The oxylance(100) as claimed in claim 1, wherein the long pipe is being made up of cast iron or stainless steel.
3. The oxylance(100) as claimed in claim 1, wherein the thermocoupleshave capacity of measuring temperature upto1500 deg. C.
4. The oxylance(100) as claimed in claim 1, wherein the long pipe comprises atleast one hollow pipe (112a, 112b) coupled with to channel compressed air to the long pipe.
5. The oxylance(100) as claimed in claim 1, wherein the long pipe is coated with refractory material.