Claims:WE CLAIM:
1. An expert advisory system (100) for identifying blast furnace abnormal process condition, the expert advisory system (100) comprising steps:
reading data from a plurality of sensors;
storing data in a database of the expert advisory system (100);
developing algorithms for process parameters based upon the stored data;
developing a set of rules based upon the process parameters;
identifying problems associated with the set of rules;
identifying abnormal conditions associated with the blast furnace based upon the process parameters;
triggering a suggestion based upon the identified abnormal conditions;
displaying the suggestion to operator of the blast furnace;
initiating a corrective action by the operator based upon the suggestion;
changing the process parameters of the blast furnace based upon the corrective action; and
reinitiating the reading data from the plurality of sensors to achieve a closed loop path.
2. The expert advisory system (100) as claimed in claim 1, wherein the plurality of sensors is one of temperature sensor, level sensor, pressure sensors.
3. The expert advisory system (100) as claimed in claim 1, wherein after reading of the plant data, it is stored in the database of the expert advisory system (100) along with a timestamp in systematic manner such that it can easily retrieved by expert advisory system (100) as and when required.
4. The expert advisory system (100) as claimed in claim 1, wherein the suggestion being accepted by the operator, are downloaded to the blast furnace.
5. The expert advisory system (100) as claimed in claim 1, wherein the changing of the process parameters is done through a PLC controller.
6. The expert advisory system (100) as claimed in claim 1, wherein the set of rules includes Slag Composition Rule, casting rule, thermal rule.
7. The expert advisory system (100) as claimed in claim 6, wherein the slag composition rule includes Slag liquidus temperature-based rule, and Slag viscosity-based rule.
8. The expert advisory system (100) as claimed in claim 6, wherein the casting rule includes Drill bit selection and GUTKO time-based rule, and Liquid level-based rule.
, Description:AN EXPERT ADVISORY SYSTEM FOR IDENTIFYING BLAST FURNACE ABNORMAL PROCESS CONDITION
FIELD OF INVENTION
[001] The present invention relates to abnormality detection in a blast furnace, more particularly towards an expert advisory system for triggering a suggestion based upon the abnormality detection.

BACKGROUND OF THE INVENTION

[002] Blast furnace is a tall giant structure which processes various raw materials into liquid products. Blast furnace is charged with alternate layers of coke and Fe bearing materials such as lump or, Sinter and/or Pellet. Over years of operation and development of various process models the blast furnace visualization has improved. Although, the mathematical models developed have made operators to better visualize the blast furnace, observe the phenomenal changes occurring inside the furnace, still an automatic system is required to further facilitate the operation of blast furnace. It is so because even the skilled operators might make mistakes in taking suitable decision and it depends on individual operator. The delay in the decision may elapse the time for recovery of the furnace as well. Instead an online system, capable of taking the right decision at the required time can mitigate the abnormality in the furnace.

[003] Attempts are made in the past for the development of expert system and many successful implementations have been reported. In ironmaking blast furnaces several attempts are made to implement the expert system for various reasons, such as to facilitate operation to maintain a stable furnace condition, prediction of heat or heat tendency of the furnace, prediction of HMT, etc. It can become a tool for the smooth operation of the blast furnace. In various places, rule based expert system is made while in other part of the world hybrid or heuristic models are deployed. The aim of every implementation remains the same, but operational constraints limit the proper implementation of expert system in blast furnace. Such expert systems possess the potential to reduce the manpower, save the energy, improve the operational practice and thereby increase the productivity of the furnace.

[004] Only after the implementation of a closed loop blast furnace expert system, significant improvement in the production cost and availability can be perceived. However, there still exist certain operational limitations that hinder the complete implementation of expert system for closed loop process control. Much work is done in the adaptive controllers and expert advisory system monitoring the dynamic changes occurring in the blast furnace process. One of the challenges is to design an expert system that can predict the tuning process parameters, while guaranteeing the performance improvement and furnace stability using the advisory system. Secondly the closed control loop is much difficult than an open control loop involving human invention to close the loop. In closed control loop the time elapsed during the human invention to take the decision is minimized, and the response time is fast to control any contingencies occurring in the furnace.

OBJECTIVE

[005] An object of the invention to propose a process of identifying any abnormality occurring in the blast furnace process based on the expert advisory system.

[006] Another object of the invention is to propose changes to the operators to correct the abnormal process condition by making the correct level of changes.

[007] Another object of the invention is to reduce the delay time of the process control and reduce the expensive items such as coke rate, PCI rate and improve the production rate.

SUMMARY OF THE INVENTION

[008] The present disclosure relates to an expert advisory system (100) for identifying blast furnace abnormal process condition. The expert advisory system (100) comprising steps: reading data from a plurality of sensors; storing data in a database of the expert advisory system (100); developing algorithms for process parameters based upon the stored data; developing a set of rules based upon the process parameters; identifying problems associated with the set of rules; identifying abnormal conditions associated with the blast furnace based upon the process parameters; triggering a suggestion based upon the identified abnormal conditions; displaying the suggestion to operator of the blast furnace; initiating a corrective action by the operator based upon the suggestion; changing the process parameters of the blast furnace based upon the corrective action; and reinitiating the reading data from the plurality of sensors to achieve a closed loop path.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[009] 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:
Fig. 1: Steps performed by an expert advisory system 100 for the operation of the changes in blast furnace process parameters in accordance with an embodiment of the present disclosure
Fig 2: An exemplary user interface (UI) associated with the expert advisory system 100, wherein current status of process parameters is shown
Fig. 3: An exemplary number of suggestions generated by the expert advisory system 100

[0010] 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.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

[0011] The present invention, now be described more specifically with reference to the following specification.

[0012] 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.

[0013] 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.

[0014] Figure 1 illustrates steps performed by an expert advisory system 100 for the operation of the changes in blast furnace process parameters in accordance with an embodiment of the present disclosure. The expert advisory system 100 uses a set of composite rules and generates a suggestion. The suggestion is generated based on the criticality of the process conditions. For instance, a process which is alarming may be given only small changes for recovery, while a process which has become critical may require the major changes in the process conditions.

[0015] The sequence of the steps will now be described in the foregoing description. At step 102, all the process data are read from a plurality of sensors. These sensors include temperature sensor, level sensor, pressure sensors. At step 104, after reading of the plant data, it is stored in database of the expert advisory system 100 along with a timestamp in systematic manner such that it can easily retrieved by expert advisory system 100 as and when required. At step 106, algorithms are developed for process parameters. At step 108, rules are developed based on the process parameters.

[0016] After that, at steps 110-114 the expert advisory system 100 modules monitor the status of process parameters and based on the set of rules triggers suggestions. The suggestion is triggered based on the condition of the process. At step 116, the suggestions are displayed to some operator / operators of the blast furnace. The decision to accept or reject the suggestion, lies with the operators sitting in the main control room, operating the blast furnace. A suggestion accepted by the operators means the new setpoints suggested by the operator is to be downloaded to the blast furnace, at step 118. At step 120, based on the downloaded suggestions, changes are done to PLC controller. At step 122, the PLC controller makes changes in the process parameters of the blast furnace. For example, a valve of the pressure sensor may be adjusted according to the suggestions triggered. Further, the expert advisory system 100 follows a closed loop path, and step 102 is initiated.

[0017] Figure 2 shows an exemplary user interface (UI) associated with the expert advisory system 100, wherein current status of process parameters is shown. In this case HMT is shown as 1512 deg C and Hot metal Si is shown as 0.626%. This means that the current status is shown based on a compound condition which has arises. The compound condition is HMT is between 1505-1515 deg C while Si between 0.61 to 0.8%. The expert advisory system 100 using the rules developed at the background will process and will trigger a suggestion accordingly and has therefore given a suggestion to increase the PCI by 3 Kg/thm. The final decision to accept/reject the suggestion generated by the expert system lies with the control room operators, who are running the blast furnace. The expert advisory system 100 gives the suggestion the moment an abnormal condition arises, without any delay. Therefore, the total time required to bring the furnace to the normal condition from abnormal condition can be reduced using this system.

[0018] Figure 3 illustrates an exemplary number of suggestions generated by the expert advisory system 100.

[0019] Examples associated with the expert advisory system 100 are mentioned in the foregoing description, wherein suggestions are provided by the expert advisory system 100 based upon certain conditions associated with the blast furnace. In an example, the conditions and suggestions are based on certain rules (mentioned earlier) described below.
1. Slag Composition Rule
a. Slag liquidus temperature-based rule:
S. No. Condition Suggestion
1 HMT1460 High liquidus temperature
b. Slag viscosity-based rule:
S. No. Condition 1 Condition 2 Suggestion
1 Slag_Visc>2.8 poise Al2O3>19% Reduce the Al2O3target to <19%
2 Slag_Visc>2.8 poise MgO>8.5% Reduce the Al2O3target to <19%
3 Slag_Visc>2.8 poise HMT<1485 oC Increase the fuel rate to achieve HMT>1495 oC
4 Slag_Visc<2.8 poise Wind_Vol<280000 Nm3/hr any time in last 4 h No Action is required
2. Casting Rule
a. Drill bit selection and GUTKO time-based rule:
S. No. Condition Suggestion 1 Suggestion 2 Suggestion 3
1 Avg Prod_Rate<8700 thm in last 3 hours Open casting with drill bit of 55 mm Maintain GUTKO of 180 minutes No Overlapping cast
2 Avg Prod_Rate is between 8700 – 8900 thm in last 3 hours Open casting with drill bit of 60 mm Maintain GUTKO of 180 minutes Maximum overlapping of 10 minutes
3 Avg Prod_Rate is between 8900-9200 thm in last 3 hours Open casting with drill bit of 60 mm Maintain GUTKO of 180 minutes Maximum overlapping of 20 minutes
4 Avg Prod_Rate is between> 9200 thm in last 3 hours Open casting with drill bit of 63 mm Maintain GUTKO of 180 minutes Maximum overlapping of 25 minutes

b. Liquid level-based rule:
S. No. Condition 1 Suggestion 1 Suggestion 2 Suggestion 3
1 Liquid_Level>20% No change in GUTKO time Open another side cast with same drill bit
2 Liquid_Level>30% for last 2 consecutive cast Decrease GUTKO time to 60 minutes Open another side cast with same drill bit
3 Liquid_Level>20% for 2nd time Change GUTKO time to 180 minutes Open another side cast with one size bigger drill bit
4 Liquid_Level>20% for 2nd time Decrease GUTKO time to 60 minutes Decrease drill bit size with one size lower Close the cast till the cast blows out
5 Liquid level >20% again Decrease GUTKO time to 60 minutes Decrease drill bit size with one size lower Close the cast till the cast blows out

3. Thermal Rule
S. No. Condition 1 Condition 2 Condition 3 Condition 4 Condition 5 Suggestion 1 Suggestion 2
1 0.75 < Si <0.9 HMT >1510 oC Blast pressure <3.8 Coke rate is increased in last 6 h Coke/Coal ash or moisture is reduced Wait for the next 2 torpedo analysis
2 0.75 < Si < 9.0 for another torpedo analysis HMT >1510 oC Blast pressure <3.8 Coke rate is increased in last 6 h Coke/Coal ash or moisture is reduced Decrease PCI by 3 Kg/thm
3 1.2 < Si <0.9
HMT >1520oC
Reduce coal rate by 5kg
Reduce RAFT by 50 oC for 30 minutes
4 0.6 < Si < 0.8
1495 < HMT < 1510
No action is Required

[0020] 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.