Claims:WE CLAIM:
1. A probing system for in-situ real-time continuous measurement of material discharged in blast furnace comprising
at least one probe for inserting into the blast furnace covering fall of the discharged material from discharge chute of the blast furnace anywhere from centre to wall of the blast furnace;
said probe includes
plurality of micro-switches for impact force based interception of the discharged material covering entire inserted span of said probe to experience impact of the falling discharged material, each of said micro-switch generates a motion on impact of the falling material, and
plurality of micro-contactors on said probe, each cooperative to one of the micro-switches for converting the motion into an equivalent electronic signal;
processing unit operatively connected with the probe for receiving the signals from the micro-contactors and calculating therefrom profile of the discharged material.

2. The probing system as claimed in claim 1, wherein the micro-switch comprises
at least one impact sensing plate for exposing to the falling discharged material and receiving its impact;
at least one spring loaded support cooperative to said impact sensing plate and configured to be activated on impact of the falling material generating the motion proportional to size, weight of material particle striking the impact sensing plate; and
said micro-contactor cooperative to the spring loaded support to convert the motion into the electronic signal for precise identification of the impacting particle type, size and the impact force by the processing unit based on calibration and co-relation and thereby complete interception of the material discharged in the blast furnace.

3. The probing system as claimed in claim 1 or 2, wherein the impact sensing plate comprises an impact plate preferably made of steel sheet covered by an impact shoe facing towards the discharging chute for exposing to the falling material from the discharge chute operated at various angular positions.

4. The probing system as claimed in anyone of claims 1 to 3, wherein the impact shoe is covered by a buffer sheet preferably made of rubber to absorb the impact forces and avoid bouncing of the material from the impact shoe surface making a good contact with the surface.

5. The probing system as claimed in anyone of claims 1 to 4, wherein the spring loaded support comprises
a shaft for resilient fitting of the impact plate on the spring and transfers the impact force to the spring when the falling material strikes the impact plate; and
sliding piston on said spring to capture compression motion of the spring under the impact force and replicate a to and fro motion which is proportional to size, weight of the impacting material particle striking the plate.

6. The probing system as claimed in anyone of claims 1 to 5, wherein the processing unit cooperative to the micro-contactor differentiates impacting iron bearing particle from impacting coke particle present in burden material discharged in the furnace based on difference in the electronic data signal of the micro-contactor resulting from different motion of the spring loaded support for impacting of the iron bearing particle and the iron bearing particle on the impact sensing plate.

7. The probing system as claimed in anyone of claims 1 to 6, wherein the probe comprises U-shaped housing made of steel having a front portion for inserting into the blast furnace accommodating the micro-switches and an integrated back portion for disposing outside of the blast furnace while the front portion is inserted within the blast furnace accommodating the micro-contactors;
wherein the micro switches of the front portion are connected to the micro contactors of the second portion by involving a data communication cable laid internally through a cable way bottom of the probe housing.

8. The probing system as claimed in anyone of claims 1 to 7, wherein the micro-switches are accommodated in the front portion of the U-shaped housing having their impact sensing plate facing toward open end of the U-shaped casted housing for exposure to the falling discharged material, whereby said micro-switches are sequentially arranged in the front portion with a fixed centre to centre distance between consecutive micro-switches to form a continuous impact sensing top surface on the inserted length of the probe.

9. The probing system as claimed in anyone of claims 1 to 8, center to center distance of the measuring sensor assembly is fixed at 50 mm to sense large particle sizes of coke with diameter about 50 mm present in the burden material discharged in the furnace.

10. The probing system as claimed in anyone of claims 1 to 9, wherein the probe is positioned horizontally in the blast furnace such as to ensue one end of the impact sensing top surface is at centre of the furnace while the other end is at wall of the furnace.

11. The probing system as claimed in anyone of claims 1 to 10, wherein the processor calculates profile of the discharged material including determination of stream width or boundary limits of trajectory path of the burden material for both coke and iron bearing material and for each of selected chute angles, characteristics of stray particle position in the flow for each of the material, distribution characteristics of the material in the flow path during its flight in free fall zone of the furnace from the signals received from the micro-contactors corresponding to impacting material dependent impact force and time of contact as determined by the micro switches and position of the determining micro switches on the probe with respect to the furnace wall and centre.

12. A system for in-situ real-time continuous measurement of stream width of the material discharged in blast furnace involving the probing system as claimed in anyone of claims 1 to 10, comprise two numbers of the probes;
said probes are positioned at two levels of the blast furnace diagonally opposite to each other in such a way that the falling material is intercepted by the probes independently at two different levels;
said processing unit maps the stream width determined for the probes to determine continuous widening of the stream width of the falling material due to continuous rotation of the discharge chute.

13. The system as claimed in anyone of the claims 1 to 12, wherein the processing unit embeds program for display of data from the probe in tabular and graphic formats through menu options.

Dated this the 29th day of May, 2019 Anjan Sen
Anjan Sen & Associates
(Applicants Agent)
IN/PA-199
, Description:FIELD OF THE INVENTION:
The present invention relates to online measurement of burden material stream width during flight of the burden material in free fall zone of blast furnace stack. More specifically the present invention is directed to develop a system for in-situ real-time accurate measurement of the burden material stream width and extraction of information regarding stray particles position in the burden material stream through the flight, distribution characteristics of burden material in the flow path during it’s flight in the free fall zone for all possible discharge angles from material distributor of the blast furnace for the burden distribution and control. The present system can be used to eliminate interruptions during material discharge in the furnace and saves time.

BACKGROUND OF THE INVENTION:
Modern Blast furnaces for iron making are equipped with Paul-Wurth distributor for the burden material charging and distribution inside the furnace. The burden material in the blast furnace operation basically consists of iron bearing material (sinter, pellets, lump iron ore) and coke which are discharged in separate layers and the material descends down the furnace as a result of gradual reduction and melting of iron bearing material. The material discharged from the tip of the distributor travels through the free fall zone and fall on the stock line. Generally, the iron bearing material and coke layers maintain their ‘as charged’ stratification well during the descent to the lower parts of the furnace.
The stock line profile is governed by the repose angle which depends on material quality, granulometry, stream width which in turn controls the `Flatness’ of the material deposit and volume of the deposit. Material stream width is the most important parameter for calculating the trajectory of the material during its fall in the free fall zone and to estimate the stock profile.
It is extremely difficult and time consuming to account for the behaviour of the flow of granular material as in the blast furnace charging system. The differential density and size parameters of the material result in stratification and affects the stream width. Small stray particles tend to scatter and fly away from the main stream due to the centrifugal forces and does not contribute to the main flow width of the stream.
The current method of determining the material stream width is to insert a lime coated pipe inside the furnace such that, the material during its fall strikes over the pipe. The coke and iron bearing material make a dent on the pipe at places where it hits the pipe. After each discharge the pipe is withdrawn from the furnace and the flow width is measured manually by visual inspection on the pipe for the impact marks.
Subsequent to the measurement, the pipe surface is cleaned and coated with fresh lime coating and inserted again into the furnace. This procedure results in a delay time of at least about one hour for each operation and the charging is stopped during the time. Further, the measurements often include some errors on account of manual assessment of material impact marks, marks made by stray particles flying away from the main stream which result in erroneous calculations of the material trajectories and the stock line profiles.
Recently few systems for measuring the material trajectory path in the furnace have been reported, e.g.
BE1012905A3 dated 17-09-2001 disclosed and developed an optical fibre probe which is based on the method of using a probe whose inner portion to the chamber of the furnace is free of sensors. Use of a probe inserted radially into the furnace above the charge level, so that the probe is subjected to the impact of falling material falling from the chute and probe is equipped with optical sensors disposed within the furnace and designed to detect the point of impact. This probe is designed for measurement of material trajectory path by detecting the impact point. However, the method of measurement is prone to errors particularly at the end points and does not compensate for the smaller stray particles impacting on the probe. In this method the construction of the trajectory is made based on two points which gives an indicative picture only of the trajectory path. Further this method does not provide the data on the actual material stream width also does not provide for measurement and mapping of particle distribution in the stream.

JP2015120964A dated 2015-07-02 disclosed a method of measuring a falling trajectory of charged materials in a blast furnace with high accuracy in an environment with massive dust during a regular operation. In this invention the probe is basically consisting of microwave sensors. During the material fall, microwaves radiated from the microwave oscillators provided above the charge in the blast furnace, the reflected microwave is measured. However, the above system and method are not only expensive, also have high maintenance probability. Further, the reflected microwave can alter and is a function of material and the size of the particle. The microwave reflected from stray particles are also considered in the detection and the measurement is effective only at a single radial position and does not take care of the spread of material due to segregation and gravitational forces on the particles.
CN202482341U dated 2012-01-09, disclosed a distribution trajectory detector for a bell-less top of a blast furnace. The detector comprises a base flange, a holder and a detecting rod. The base flange matching with a mounting flange of a water spray gun at the top of the blast furnace is fixed with the mounting flange of the water spray gun. This invention relates to blast bell-less top cloth locus detection means includes a base flange, and probe holder, and the top of the foot flange, mounting flange, adapted gun sprinkler. The sprinkler gun mounting flange is fixed to the cradle on the base end flange, and the other end is connected to the hinge on the probe end. The probe in the furnace is in vertical state by its own weight during the chute rotation and when the charge falls on the top cloth fixed to the chute and the probe, will form a relatively clear traces, thereby facilitating the measurement of material width. The method and system in the Chinese patent as above has limitations such as requirement of change of cloth for each of the measurements, cumbersome mechanisms to be adjusted and fitted each time for measurements and elaborate fixing arrangements to be carried out. The method of measurement necessitates delays and stoppages of the charging. Further, the traces /marks made by the stream of material is not very accurate since, the marks made by all kinds of particle sizes are reflected and is difficult to differentiate the particle sizes based on the intensity of the trace/mark made on the cloth.
The above thus clearly suggest that there has been a need for developing cost effective reliable easily operable solution for in-situ real-time accurate measurement of the burden material stream width and extraction of information relating to the burden material stream for the burden distribution and control eliminating the delays and stoppages required during the furnace charging.

OBJECT OF THE INVENTION:
It is thus the basic object of the present invention is to develop a system for in-situ real-time accurate measurement of the burden material stream width during flight of the burden material in free fall zone of blast furnace stack.
Another object of the present invention is to develop a system for in-situ real-time accurate measurement of the burden material stream width during flight of the burden material in free fall zone of blast furnace stack which would be adapted to extract information relating to the burden material stream for the burden distribution and control eliminating the delays and stoppages required during the furnace charging.
Yet another object of the present invention is to develop a system for in-situ real-time accurate measurement of the burden material stream width during flight of the burden material in different radial locations of the blast furnace and measuring the particle size distribution in the material stream in the free fall zone of the blast furnace top.
A still further object of the present invention is to develop a system for in-situ real-time accurate measurement of the burden material stream width and extraction of information regarding stray particles position in the burden material stream through the flight, distribution characteristics of burden material in the flow path during it’s flight in the free fall zone for all possible discharge angles from material distributor of the blast furnace for accurate and sufficient data capture for development of material trajectories and subsequent stock line profiles of the material deposited inside the furnace from a Paul-Wurth charging mechanism.

SUMMARY OF THE INVENTION:
Thus according to the basic aspect of the present invention there is provided a probing system for in-situ real-time continuous profiling of material discharged in blast furnace comprising
at least one probe for inserting into the blast furnace covering fall of the discharged material from discharge chute of the blast furnace anywhere from centre to wall of the blast furnace;
said probe includes
plurality of micro-switches for impact force based interception of the discharged material covering entire inserted span of said probe to experience impact of the falling discharged material, each of said micro-switch generates a motion on impact of the falling material, and
plurality of micro-contactors on said probe, each cooperative to one of the micro-switches for converting the motion into an equivalent electronic signal;
processing unit operatively connected with the probe for receiving the signals from the micro-contactors and calculating therefrom the profile of the discharged material.

In a preferred embodiment present probing system, the micro-switch comprises
at least one impact sensing plate for exposing to the falling discharged material and receiving its impact;
at least one spring loaded support cooperative to said impact sensing plate and configured to be activated on impact of the falling material generating the motion proportional to size, weight of material particle striking the impact sensing plate; and
said micro-contactor cooperative to the spring loaded support to convert the motion into the electronic signal for precise identification of the impacting particle type, size and the impact force by the processing unit based on calibration and co-relation and thereby complete interception of the material discharged in the blast furnace.

In a preferred embodiment present probing system, the impact sensing plate comprises an impact plate preferably made of steel sheet covered by an impact shoe facing towards the discharging chute for exposing to the falling material from the discharge chute operated at various angular positions.

In a preferred embodiment present probing system, the impact shoe is covered by a buffer sheet preferably made of rubber to absorb the impact forces and avoid bouncing of the material from the impact shoe surface making a good contact with the surface.

In a preferred embodiment present probing system, the spring loaded support comprises
a shaft for resilient fitting of the impact plate on the spring and transfers the impact force to the spring when the falling material strikes the impact plate; and
sliding piston on said spring to capture compression motion of the spring under the impact force and replicate a to and fro motion which is proportional to size, weight of the impacting material particle striking the plate.

In a preferred embodiment present probing system, the processing unit cooperative to the micro-contactor differentiates impacting iron bearing particle from impacting coke particle present in burden material discharged in the furnace based on difference in the electronic data signal of the micro-contactor resulting from different motion of the spring loaded support for impacting of the iron bearing particle and the iron bearing particle on the impact sensing plate.

In a preferred embodiment present probing system, the probe comprises U-shaped housing made of steel having a front portion for inserting into the blast furnace accommodating the micro-switches and an integrated back portion for disposing outside of the blast furnace while the front portion is inserted within the blast furnace accommodating the micro-contactors
wherein the micro switches of the front portion are connected to the micro contactors of the second portion by involving a data communication cable laid internally through a cable way bottom of the probe housing.

In a preferred embodiment present probing system, the micro-switches are accommodated in the front portion of the U-shaped housing having their impact sensing plate facing toward open end of the U-shaped casted housing for exposure to the falling discharged material, whereby said micro-switches are sequentially arranged in the front portion with a fixed center to center distance between consecutive micro-switches to form a continuous impact sensing top surface on the inserted length of the probe.

In a preferred embodiment present probing system, the center to center distance of the measuring sensor assembly is fixed at 50 mm to sense large particle sizes of coke with diameter about 50 mm present in the burden material discharged in the furnace.

In a preferred embodiment present probing system, the probe is positioned horizontally in the blast furnace such as to ensue one end of the impact sensing top surface is at centre of the furnace while the other end is at wall of the furnace.

In a preferred embodiment present probing system, the processing unit calculates profile of the discharged material including determination of stream width or boundary limits of trajectory path of the burden material for both coke and iron bearing material and for each of selected chute angles, characteristics of stray particle position in the flow for each of the material, distribution characteristics of the material in the flow path during its flight in free fall zone of the furnace from the signals received from the micro-contactors corresponding to impacting material dependent impact force and time of contact as determined by the micro switches and position of the determining micro switches on the probe with respect to the furnace wall and centre.

According to another important aspect of the present invention there is provided a system for in-situ real-time continuous measurement of stream width of the material discharged in blast furnace involving the above probing system comprise two numbers of the probes;
said probes are positioned at two levels of the blast furnace diagonally opposite to each other in such a way that the falling material is intercepted by the probes independently at two different levels;
said processing unit maps the stream width determined for the probes to determine continuous widening of the stream width of the falling material due to continuous rotation of the discharge chute.

In the present system, the processing unit embeds program for display of data from the probe in tabular and graphic formats through menu options.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS:
Figure 1a shows probe assembly with micro switches associated with present system for in-situ real-time accurate measurement of the burden material stream width in the blast furnace stack and extracting analyzable information thereof.

Figure 1b shows photograph of the assembled probe assembly in accordance with an embodiment of the present invention.

Figure 2 shows the micro switch associated with present system in accordance with an embodiment of the present invention.

Figure 3 shows electronics unit associated with present system in accordance with an embodiment of the present invention.

Figure 4 shows positioning of the probe assembly in the blast furnace in accordance with an embodiment of the present invention.

Figure 5 shows electronic and logic gate assembly with integrated circuit associated with processing unit of the present system.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:
In accordance with the objects(s) of this invention, as embodied and broadly described herein, this invention discloses a system for on-line measurement of stream width and profiling of material discharged in blast furnace by using the probe assembly with micro switches which are specifically configured to impact force based interception of the material discharged in the blast furnace.
The probing system of the present invention which enables the in-situ method for on-line measurement of the material stream width during its descent through the free fall zone of the blast furnace and the method of data capture, analysis and data display basically comprises one or more probes. These probes are configured to be disposed inside the furnace for measurement of the material flow width in continuity for building the trajectory path of the discharged material. The system of present invention also involves co-operative electronics for mapping the particle distribution in the stream based on impact force exerted by the particle on the micro-switches fixed on the probes and width of particles flow stream. The present system is further enabled for determining a co-relation function by comparing the impact force exerted by the falling particle on the probe with it’s size and type. The system can perform the measurements and data analysis and present the data in real-time and online. The invention also includes an in-situ method for measurement of the material stream width which forms the boundary limits of the material trajectory during its free fall in the furnace.

An important object of present invention is the design of the measuring probe. The probe comprises two components (1) Mechanical (2) Electronics.
The mechanical section of the probe is inserted in the furnace and exposed to the falling material inside the furnace. In a preferred embodiment, the mechanical part of the probe is designed and fabricated with MOC as CRC steel. The mechanical section of probe consists of pressed housing profile to form a box or U shaped enclosure. The housing is strengthened internally to withstand the vertical and oblique impact forces imparted on the probe by the falling of the burden material. The mechanical part of the probe is fitted with number of micro-switches contact assemblies at a centre to centre distance of 50 mm covering the entire span of the mechanical part. The electronic part of the probe is fitted with electronics for signal conditioning and data communication. The numbers of the micro-switches are not limiting factor and can be increased or decreased as per effective length of measurement which is dependent on shaft diameter of the furnace under consideration for the measurements. The centre to centre distance of the measuring sensor assembly is fixed at 50 mm and shall be constant and takes care of large particle sizes of coke @ 50 mm present in the burden material discharged in the furnace.
The micro-switch on the probe which provided for impact force based interception of material discharged in the blast furnace is constructed consisting of an impact sensing plate mounted on pre calibrated spring loaded support. The impact sensing plate is provided for exposing to discharged material falling from discharge chute of the blast furnace and receiving impact of the falling material while the spring loaded support is configured to be activated on impact of the falling material and generate a motion equivalent to the impact and proportional to size, weight of material particle striking the impact sensing plate. The impact sensing plate is covered with rubber sheet to absorb the impact forces and avoid bouncing of the material from the surface of the probe and make a good contact with the surface. Further the probe is provided with butyl rubber sheathing capable of taking continuous impact loads. The rubber covering shall act as a dust sealant and also prevent material from setting on the probe due to bouncing action.
In the further aspect of present invention, the mechanically designed portion of probe housing the electronics is provided with removal cover for enabling easy maintenance of connections. The top portion of the contactor assemblies are provided with thick rubber padding.
In an another aspect of the invention, once the burden material is discharged by the Paulwurth distributor chute, the burden material travels through the free fall zone till it is deposited on the material in the furnace stack. During the fall of material, the material experiences both gravitational and centrifugal forces (due to the rotational speed of the chute) and follows a curvilinear path during its flight. Also during the flight material segregation takes place allowing small size and lighter particles to deflect from the main flow (Stray particles). This motion of the falling material results in constant widening in the flow width. It is essential to measure the material flow width at different distances during the material flight downwards to the bottom, determine the extreme boundaries of the material steam so as to calculate the material layering structure and profile in the furnace stack. An optimized material profile and structure provides an optimized furnace performance due to better gas distribution and uniform descent of the burden material.
The furnace stack at the top is provided with man-holes to facilitate repairs and maintenance. The material free fall distance from the distributor chute to the operating stock line is generally around 1.5-2 M. A blast furnace is symmetrical around its radius and hence any measurement at a fixed radial position will represent the same on the opposite side of the centre line of the furnace.
Further, when the falling material impacts the intercepting probe, the material subsequent to striking on the probe gets deflected from the original path. Hence measurements of the material flow width at different heights during the material flight are essential to capture the material trajectory. To achieve this objective, a set of two probes are positioned diametrically opposite at two different levels in the furnace stack.
The probes are positioned in the furnace in such a way that, the falling burden material is intercepted by the probe. In the frame of reference on this object of invention the said electronic probes are introduced into the furnace horizontally through the man holes at the top of the furnace, such that it is directly placed under the material being discharged through different angular position from the rotatory chute. Two numbers of the said electronic probe introduced inside and positioned diagonally opposite to each other. The falling material during its flight picks up kinetic energy and exerts an impact force proportional to the type of material, size and its bulk density. When the material impacts the probe surface, the micro contactor in the respective assembly gets activated. Due to the rubber cladding provided over the impact plate of the switch assembly, the material does not deflect and makes a good contact. The contact time is dependent on the type, shape and the impact force exerted by the weight of the material. Heavy and large sized iron particles exert more force and result in longer contact time compared to others. Similar is the case with coke particles. The time of contact and the distance of compression on the spring is measured as the electronic signal in volt unit and the data from each section is transmitted to the data controller at the end of the probe.
The positioning of the probes as above facilitates measurement of the material flow width which can be considered as the true width due to the radial symmetry of the furnace. The data is processed by the electronic circuitry to construct the material trajectory during its flight. The data processing with inbuilt correlation algorithm facilitates mapping of particle distribution in the stream based on the impact force and time of contact of the micro switches/contactors.
The electronics provided in the probe consists of two parts. (1) Electronics attached within the probe and (2) Portable electronics processor and display unit.
Electronics within the probe consists of signal conditioning cards and terminal boxes. All the connectors are of phoenix industrial connectors suitable for rugged operation. The signal cables from each of the contactor assembly are run through specially provided cable slot at the bottom of the probe and are terminated in the phoenix connector.
The falling material during its flight picks up kinetic energy and exerts an impact force proportional to the type of material, size and its bulk density. When the material impacts the probe surface, the micro contactor in the respective assembly gets activated. The contact time is dependent on the type, shape and the impact force exerted by the weight of the material. Heavy and large sized iron particles exert more force and result in longer contact time compared to others. Similar is the case with coke particles. The electronic signal automatically is deactivated when the particle drops off the probe. The time of contact and the distance of compression on the spring is measured as the electronic signal in milli volts and the data from each section is transmitted to the signal conditioner circuitry at the end of the probe. The power supply required for the probe operation is provided from the display and processor unit.
In further aspect of present invention of said probe, the electronics processor and display unit is separate portable equipment as shown in Fig-4. The display unit is designed to operate on 220V, 50Hz A.C power supply. All the other voltages required for the electronics are generated internally. The display unit have female 3 pin plug socket for AC supply, ON/OFF switches, fuse, phoenix signal connectors for connecting signal cables from the said probe, 9 pin D-type connector for RS 485 connection to enable data communication to a PC.
For connecting the signal cables from the probe to the display unit, LAP cables are used. The signal cables are drawn through LAP polyethylene conduit capable of withstanding high impact forces and abrasion.
Now a preferred embodiment of the present probing system for in-situ real-time continuous profiling of material discharged in blast furnace is specially disclosed with the reference to the illustrations of the accompanying figures.
Reference in this context first invited from the accompanying Figure 1a which shows the assembly of mechanical and electronics part of the Probe for measuring the stream width of the burden material in the free fall zone of the furnace. The whole assembly of said probe 206 & 208 (as shown in figure 3) is divided into two sections viz. a first or front portion 301 for inserting into the blast furnace and a second or integrated back portion 302 for disposing outside of the blast furnace while the front portion 301 is inserted within the blast furnace. The first section 301 which is the insertable length of the probe is fitted with micro contactor assemblies (represented in figure 2) at a centre to centre distance of 50 mm and covering an effective measuring length of 2000 mm and forming a continuous impact sensing top surface on the inserted length of the probe. Around 40 switches are incorporated in this overall length of 301 section and every switch consist of whole assembly as described in figure 2. The second section 302 of the said probe has effective length of 400mm and is fitted with signal conditioning and data communication circuitry and the terminal boxes. The micro switch assemblies of 301 are connected to the signal conditioning electronics or micro contactors of 302 using an RS 485 data communication cable laid internally through a cable way at the bottom of the probe. Hence the total effective length of probe is 2400mm and this section is made of IS 2062 CRC steel profile pressed housing to form boxed enclosure of 2400mm long. All the connectors used are of phoenix industrial connectors 307 suitable for rugged operation. The signalling cables are run through a PVC cable hose 306 and connected to inlet port of the processing unit 300. The signalling cable 306 is multi-shield “foil & braid” shield triple laminate foil with drain one AWG size smaller (30 AWG to 10 AWG gauge) insulated conductors encapsulated with tinned copper braid for increased physical strength and superior shielding from signal interference. The micro switches on the measuring length of the probe 301, get activated on impact of the falling material and distance of the spring compression due the impact force and the time of contact is converted into electronics signal by the electronics housed in 302. The processed signals are transmitted to the processing unit 300 via RS 485 communication cable. The accompanying figure 1b shows the probe in the final fabricated condition.
The accompanying figure 2 shows the details of the micro-switch. The micro- switch as described in the invention mainly consists of two parts viz the impact sensing plate and the spring loaded support cooperative to the impact sensing plate.

The impact sensing plate comprises striking/impact plate 107, which is made of steel sheet, an impact shoe 106 covering the /impact plate 107 facing towards the discharging chute for exposing to the falling material from the discharge chute operated at various angular positions and a buffer sheet covering the impact show 106. The buffer sheet 109 is made of rubber sheet it is directly exposed to the impact forces of the falling material from the burden discharge chute operated at various angular positions.

The spring loaded support is provided to support micro contactor devices as well as 106 and 109. The spring loaded support comprises a machined shaft 108 for resilient fitting of the striking plate 107 on a calibrated spring 103. Whenever, the falling material strikes the impact plate, transfers the impact force to the spring 103 resulting in the compression of the spring. The compression motion of the spring is captured by the sliding piston 102, which replicate it’s to and fro motion inside a metallic cylinder 101. This motion of calibrated spring facilitates the measurement of the impact force and the time of contact by the micro-contactor 105 cooperative to the micro-switch.

The depression of 103 indicates the impact force exerted by the falling material and is proportional to the size and weight of the particle. The spring movement is pre-calibrated through lab experimental data and a co-relation algorithm to precisely identify the particle type, size and the impact force of different burden material. The dipping of the spring is higher for heavy material for materials like iron ore, sinter etc compared to that of coal and coke.

In the present probing system, plurality of micro-contactors is provided on the probe wherein each of the micro-contactors is cooperative to one the micro-switches on the probe for converting the sliding piston motion into an equivalent electronic signal. The processing unit 300 connected with the probe receives the signals from all the micro-contactors for precise identification of the impacting particle type, size and the impact force and calculating the profile of the discharged material therefrom. In the present probing system, the processing unit is configured to differentiate impacting iron bearing particle from impacting coke particle present in burden material discharged in the furnace based on difference in the electronic data signal of the micro-contactor resulting from different motion of the spring loaded support for impacting of the iron bearing particle and the iron bearing particle on the impact sensing plate. The processor further calculates profile of the discharged material including determination of stream width or boundary limits of trajectory path of the burden material for both coke and iron bearing material and for each of selected chute angles, characteristics of stray particle position in the flow for each of the material, distribution characteristics of the material in the flow path during its flight in free fall zone of the furnace from the signals received from the micro-contactors corresponding to impacting material dependent impact force and time of contact as determined by the micro switches and position of the determining micro switches on the probe with respect to the furnace wall and centre.

The accompanying Figure 3 shows the positioning and installation of the probes inside the shaft portion of the blast furnace for the measurement of stream width of the falling material in the free fall zone of the furnace. The burden material is discharged into the furnace through the chute as per operated selected program and at different angular positions. The furnace feed hopper discharges the material through material flow gate 201, which flows through the rotating chute 203. The rotating chute on one end is connected to the gear box through a pivot 202 while the other end is free. All the types of burden material such as iron ore, sinter, fluxes, coal/coke etc travel through the chute surface and is finally discharged into the furnace. The material during its travel through the chute experiences centrifugal forces and follows a curvilinear path during its flight in the free fall zone of the furnace. The volume of the material flows out in a stream and has both lower boundary 204 and an upper boundary 205. The material during its free fall also undergoes a segregation process due to the centrifugal and gravitational forces and smaller particles move away from the main stream. Further the stream width widens continuously with distance. The exact width of the material deposit on the stock line 210, can be constructed by calculating the trajectory path followed by the material by using the stream width data.

To accurately capture the data of the material stream width during its flight through the free fall zone, the probes are positioned horizontally one below the other and diagonally opposite. The insertable length of the probe is positioned in such a way that, the one end of the measuring length is exactly at the centre of the furnace while the other end is rigidly fixed on to a suitable fixing mechanism. The probes are generally fixed through the available man holes at gas sampling platform 207 and stack temperature measurement platform 209 respectively.

The accompanying Figure 4 shows the portable signal processing unit for processing the data from the probes and presents the data in a user friendly format. The signals from the probes are communicated through an RS 484 cable and is connected to the portable electronics module 300. The electronics unit has inbuilt circuitry for processing the signals. The device 300 is provided with a number of operating keys to facilitate the operation, measurement and presentation of data in user friendly formats. The unit can be switched ON or OFF by a power toggle switch provided on the side of the unit. The front facia is provided with a number of switches for facilitating smooth operations of the unit.

An LED light 303 indicates the healthy condition of the electronics unit. A RESET button 304 facilitates starting of the system. Whenever, the system hangs or goes into a loop, the operation of this switch enables restart of the system freshly. A group of 4 soft keys 305 are provided for realizing various operational functions of the unit. The group of soft keys provided include MENU, ENTER, UP and DOWN. When the MENU switch is pressed, the system displays the menu screen on the display unit. The menu screen consists of 6 options consisting of Set dump no, Activate, Graph display, Text display, Download and Exit. The curser can be navigated among the options by use of UP and DN keys. Once an option is chosen, it can be selected by pressing the ENTER key. The ENTER key is common for most of the operations. This key is operated when a menu option is selected, data such as dump number or ring number or any data is entered, to end an operation during data collection, to start and end data download operation etc. This key plays a vital role to inform the system about the beginning, end an event or data entry.

Accompanying figure 5 represents the electronic signal processing circuitry. The processing unit consists of an electronic board with assembly of different sensors and connection of all analogue logic in a circuit. The board features an analogue header, allowing analogue signals to be accessed, preserving signal integrity, the header pin associated in this board circuit have its counts 2, 3 5 and 18. The digital control signals can be applied directly by different jumper JP1, JP2,JP3 JP4, JP6,JP7 and JP8. Different functional modular circuits are designed and assembled to facilitate ease of identification, repairs and replacement whenever necessary. All the functional moduls are connected directly to a microcontroller interface board. The micro controllers linked in this circuit are 74LS138, RS481E, 74LS373, 27C256 etc.