FIELD OF THE INVENTION
The invention relates to circumferential balance of burden distribution in a blast furnace equipped with bell-less charging device. Particularly, the invention relates to a device and a method for determining and controlling uniformity in distribution of the material in the throat of a blast furnace.
BACKGROUNDOF THE INVENTION
Blast furnace is a counter current reactor in which coke, metallics are charged from the top, and oxygen is blown from the bottom. Indirect reduction of metallics from the flowing gas is one of the most important factors for achieving high efficiency in the blast furnace. Gas which is injected from the bottom part of the furnace ascends taking the path of least resistance. Gas flow depends on the void fraction of the solids being charged from the top. Therefore, the radial distribution of the coke and metallics becomes important to achieve desired symmetric distribution bell-less top is used in modern blast furnaces. This provides the ability to charge the material at the desired location and ensures symmetry. However, bell less top operates on some logic and takes input from various sensors for ensuring symmetry.
Asymmetry in gas flow in blast furnace leads to instability of operation, less utilization of fuel and less productivity. There are few patents available which address the circumferential balance in gas distribution.
A Japanese patent, Patent no JP 1297155 of year 1981 provides a methodology to detect the deviation in circumferential distribution of blast furnace by analyzing top gas from four uptakes of the blast furnace.
A Japanese patent, Patent no JP57070209 of year 1982 describes a method of determining the circumferential distribution of gas in blast furnace by using top gas temperature, gas constituents, gas flow rate, gas pressure and tapping data.
The prior art described determining circumferential balance is by measuring the gas temperature and composition. Variation in the temperature and composition can the effect many parameters which influences it. Here in the present invention a device and methodology is developed by taking direct

response from the material distribution device which is a direct way of evaluation of circumferential balance and is accurate.
OBJECT OF THE INVENTION
In view of the foregoing limitations inherent in the prior-art, it is an object of the invention to establish a device and method related thereof for determining and controlling the circumferential balance in charging burden material inside blast furnace.
SUMMARY OF THE INVENTION:
A method for determining and controlling uniformity in distribution of the material in a blast furnace the method comprising the steps of- obtaining data from plurality of sensors (P1,P2, P3, P4, P5) coupled to the associated electronic devices; - transferring data to a control system (A) which is coupled to data cleaning and sampling means(B) and data processing means (C); -processing the data to generate an output of ring completeness index, randomness index for charging start-up and uniformity index for mass distribution; - determining the values generated with a predefined value to obtain the desired result; wherein a control feedback system (e) coupled to the processing means generates the resultant value and displays on a visualization means (D).
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
FIG. 1a illustrates a block diagram of a predicting device with its various components in accordance with an embodiment of the invention.
FIG. 1b illustrates block diagram of a user interface for processing block in accordance to the invention.
FIG. 1c illustrates block diagram of a user interface for visualization block in accordance to the invention.
FIG. 2 illustrates a flow diagram depicting various steps for determining and controlling in accordance to the invention.
Fig 3 illustrates Plots of hopper weight and LMG opening illustration logic for discharge time calculation in accordance to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:

Various embodiments of the invention provide a charging uniformity check device for determining and controlling the charging in a blast furnace equipped with bell-less top charging system. The circumferential balance predicting device comprising a plurality of sensors, the plurality of sensors being placed at various location in the bell less top charging system, the plurality of sensors (P1, P2, P3, P4, P5) being configured to sense values corresponding to parameters of hopper weight (tfp^LMG opening (/,), chute rotation angle(r), tilt angle (t)and charging matrix with respect to time and forward the sensed values to a control system means (A), the control system means (A) being coupled to the plurality of sensors, it is configured to store and forward the sensed values to a data cleaning and sampling means (B), the data cleaning and sampling means (B) is coupled to data processing (C) means, the calculating means is configured to follow following steps.
Receive and feed the sensed value of real time hopper weight to algorithm which counts the time of material charge based on drop in weight of hopper as shown in Fig 3. It also identifies the start and end point timestamp for a dump.
Fig 3: Plots of hopper weight and LMG opening illustration logic for discharge time calculation.
1. Ring completeness index (φ)
Chute rotation angle from the encoder of BLT system and tilt angle is sensed and stored in a matrix. Degree of rotation (DR) for particular tilt angle is counted and recorded in degrees as DRn, where n is number of rings formed in a single dump of burden from BLT system. Degree of
rotation is converted into fraction using formula Table-1: Parameters for Ring completeness index (φ)

Error (Fraction remaining to complete a 360o)


Ring completeness index (φ) is given by equation mentioned below
The processing means (C) being coupled to the data sampling means (B), it is configured to generate the output of φ . Control room feedback means (E) being coupled to processing means, it is configured to make following decisions.
Case-1: If φ > ɛ, burden is distributed in incomplete rings,

N is rotation speed of chute in rpm,Sf frequency of data acquisition from encoder of chute, thereby value alteration of parameters is needed to bring φ ≤
Case-2: If φ ≤ ϵ, burden is distributed in almost complete rings, thereby no value alteration of parameters is needed.
Visualization means (D) being coupled to processing means (C) and control room feedback means (E), it is configured to visualize φ, so that operator can monitor the feedback system is working as desired.
1. Randomness index for charging start-up(Rstartpoint):
Data processing means (C) being coupled to data sampling means (B) it is configured to calculate uniformity index for ore distribution(Rstart point).



Control room feedback means (E) being coupled to processing means (C) it is configured to make following decisions.
Case-1: IfRStarlpoinl>0, distribution of ore is not uniform in all sectors, thereby a value alteration of parameters is needed to bring Rstarlpoilt = 0 or close to zero.
Case-2: If RStartpoint = 0, distribution of ore is uniform in all sectors, thereby no value alteration of parameters is needed.
2. Uniformity index for mass distribution(Umass):


Data processing means (C) being coupled to data sampling means (B) it is configured to calculate uniformity index for mass distribution(Umass).
Control room feedback means (E) being coupled to processing means (C) it is configured to make following decisions
Case-1: If umass >∈ 1, (∈ 1 is material and design specific value) distribution of mass is not uniform in all sectors, thereby a value alteration of parameters is needed to bring uore = 0 or close to zero.
Case-2: If Umass < ∈ 1, distribution of mass is uniform in all sectors, thereby no value alteration of parameters is needed.

Visualization means (D) being coupled to processing means (C) and control room feedback means (E), it is configured to visualize umass, so that operator can monitor the feedback system is working as desired.
Based on three indices mentioned above a decision matrix is developed as shown below in Fig 4. The response for an index is ok (√) if it belong to its case-1, While it is not ok (×) if it belongs to case-1. Based on any of the six conditions in the matrix, it is decided if any action is needed or not. If action signal is ‘0’ no action is needed or if action signal is ‘1’ action is needed, i.e. there is need in value alteration of parameters. This decision matrix is generated in control feedback means (E). Control room feed
Table-3: Final decision matrix for block E i.e. control room feedback means.
Index Nos. | Response

× ×
× √
× √
1 1
Case-4 Case-5
1
2
3
Action Signal

√

0
Case-1

√ √
√ ×
× √
1 0
Case-2 Case-3

√
Case-6

Illustration for decision matrix:
An illustrating example (assuming ∈= 0.133 and ∈ 1 = 0.12) for final decision matrix is explained in Table-5. For case-2,4 and 5 where action signal is 1, operator need value alteration of parameters of BLT system such that action signal is 0 i.e. case-1 or case-3. Here when the BLT system belongs to case-1 or case-3, we can say that burden distribution performed by BLT system is circumferentially balanced.
Table-5: Illustration for decision matrix operation in control room feedback means.

WE CLAIM:
1. A method for determining and controlling uniformity in distribution of the
material in a blast furnace the method comprising the steps of-
- obtaining data from plurality of sensors (P1, P2, P3, P4, P5) coupled to associated electronic devices;
- transferring data to a control system (A) which is coupled to data cleaning and sampling means(B) and data processing means (C);
- processing the data to generate ring completeness index, randomness index for charging start-up and uniformity index for mass distribution;
- determining the values generated with a predefined value to obtain the desired result;
wherein a control feedback system (E) coupled to the processing means generates the resultant value and displays on a visualization means (D).
2. The method as claimed in claim 1, wherein the value of ring completeness index should ideally be lesser than ϵ.
3. The method as claimed in claim 1, wherein the value of randomness index for charging start-up should ideally be equal to zero.
4. The method as claimed in claim 1, wherein the value of uniformity index for mass distribution should ideally be lesser than ϵl.
5. The method as claimed in claim 1, wherein a decision matrix is generated in the control feedback means (E) and corrective measures are taken.
6. The method as claimed in claim 1, wherein the sensors senses parameters which include hopper weight, LMG opening (L), chute rotation angle (r), tilt angle (t) and changing matrix.
7. A blast furnace circumferential balance monitoring device for determining and controlling of material distribution in order to achieve circumferential balance of blast furnace while distributing material, the device comprising:
a. field devices for measuring of hopper weights, lower material gates opening, rotation and tilt angle of chute, controller of material distribution system etc.;

b. programmable logic controllers for acquiring data from field devices
and transmitting data to computer device;
c. a computation module for preparing the data and filtering the data
based on control limit;
d. a computation module for estimating circumferential balance of blast
furnace;
e. a computation module for communication for feedback system.
8. A method for determining and controlling uniformity in distribution of the material in a blast furnace as substantially described and illustrated herein with reference to the accompanying drawings.