CLIAMS:WE CLAIM:

1. A material conveyor belt rupture or spillage detection system comprising:
an idler supported with respect to stringer support of belt conveyors;
a collector connected to and disposed on one side of the idler and a lever disposed opposite to said collector;
a sensor means adapted to continuously sense the said lever position such that in case of belt rupture the material from the material carrying belt is collected in said collector which effects a counter upward motion of the lever and activate switching off of the conveyor.

2. A material conveyor belt rupture or spillage detection system as claimed in claim 1 wherein counter weight on the lever is balanced such that the collector plate is always 20 degrees above the horizontal plane.

3. A material conveyor belt rupture or spillage detection system as claimed in anyone of claims 1 or 2 wherein said sensor comprises an electrical sensor which is fixed with the conveyor stringer post.

4. A material conveyor belt rupture or spillage detection system as claimed in anyone of claims 1 to 3 wherein the upward motion of the lever is adapted to break the sensor circuit and thereby activates switching off of the conveyor.

5. A material conveyor belt rupture or spillage detection system as claimed in anyone of claims 1 to 4

wherein said sensor means operates on the principle of electromagnetic field in close surroundings of sensing surface for said stopping of the belt conveyor upon belt rupturing or spillage.

6. A material conveyor belt rupture or spillage detection system as claimed in anyone of claims 1 to 5 wherein the presence of a metallic object (actuator) in the operating area causes dampening of the oscillation amplitude and the rise or fall of the oscillation is identified by a threshold circuitry to change the output of said sensor.
7. A material conveyor belt rupture or spillage detection system as claimed in anyone of claims 1 to 6 wherein said sensor means comprises inductive proximity sensor and the sensor operating voltage is in the range of 5 to 60 volts DC with one NO and one NC contact.

8. A material conveyor belt rupture or spillage detection system as claimed in claim 7 wherein said NO contact is wired to nearest pull chord switch of the conveyor which in turn is already operatively connected to PLC system for protection and the sensing face is continuously sensed by the operating striker.

9. A material conveyor belt rupture or spillage detection system as claimed in claim 8 wherein said continuous sensing of object enables open contact and conveyor system tripping during cable cut, sensor damage or power failure.

Dated this the 18th day of July, 2014
Anjan Sen
Of Anjan Sen & Associates
(Applicants Agent)

,TagSPECI:FIELD OF THE INVENTION

The present invention relates to a material conveyor belt rupture or spillage detection system. More particularly, the present invention is directed to provide a simple electro-mechanical system which detects and avoids the rupture/spillage of conveyor belt for carrying raw materials in steel plant. The system according to the present invention involves a belt rupture detection device that works simply on principle of leverage wherein when the belt rupture initiates and material on the belt starts falling, the device collects the material on a collector plate and operates due to weight difference. The device is having a MS collector plate and a lever welded opposite to each other on two sides of a conveyor idler mounted on stringer support, such that when the collector plate collects material from a ruptured belt, it moves down due to weight difference and thereby operating the lever upwards on the opposite side of idler and this movement is sensed by a noncontact type inductive proximity sensor. As the lever lifts, sensor circuit breaks and command goes to stop the belt conveyor before it is snapped avoiding large scale damage of conveyor belt and favouring early repair/maintenance and minimizing downtime of plant.

BACKGROUND OF THE INVENTION

The steel manufacturing unit of the applicants is the biggest steel plant in India with a capacity of 10mt per year hot metal in a single location. Ideally to produce 10mt hot metal, raw materials requirement is around 27mt.The total raw materials are received and fed to the furnaces by Raw Material Handling Plant.

Materials are received by railway rakes and trucks and unloaded by wagon tipplers and truck hoopers. After receiving the materials, it is stacked in yard as well as feeding is done to respective furnaces. All the raw material are transported from one point to another point through belt conveyors. The total installed length of these belt conveyors are 237 kilometers. These belt conveyors are the life line for the production of the plant, any abnormalities in these conveyors directly affects the feeding of raw material to the furnaces and resulted in loss of production.

One of the major concerns for the conveyor belt is rupture due to foreign elements such as steel scrap mixed with the raw materials loaded from different locations and different sources. To avoid belt ruptures due to presence of unwanted steel scraps in raw materials, conventionally magnetic separators are installed for their magnetic separation but it has limitations in respect of size, shape and weight of the scraps. As a result, approximately 5 km length of conveyor belts is damaged/lost every year which leads to a monitory loss of Rs 2 crores every year.

There has been therefore a need in the related filed of raw material transportation through conveyor belts in steel plants, to develop a device to detect and avoid belt damages/rupture and also eliminate production loss due to failure of material handling plant and in particular due to belt rupture.

OBJECTS OF THE INVENTION

The basic object of the present invention is thus directed to provide a material conveyor belt rupture or spillage detection system for application in material handling plant which would detect occurrence of any rupture/spillage in belt immediately and stop the belt conveyor to generate alarm and initiate faster repair/maintenance.

A further object of the present invention is directed to provide a material conveyor belt rupture or spillage detection system which would save large scale damage and waste of conveyor belts by early detection of rupture/spillage occurrence in belt.

A still further object of the present invention is directed to provide a material conveyor belt rupture or spillage detection system which would be activated based on collecting materials falling from the gap generated due to through cut in carrying side of the belt but before it is snapped thus avoiding loss of longer stretches of belts.

A still further object of the present invention is directed to provide a belt rupture detection system which involves a simple yet reliable electro-mechanical device wherein downward movement of a collector plate by weight difference due to falling material thereon from ruptured conveyor belt operates a lever connected to it which is sensed by a noncontact sensor to stop the conveyor belt operation.

A still further object of the present invention is directed to provide a belt rupture detection system which involves a simple yet reliable electro-mechanical device that works on the principle of electromagnetic field in close surroundings of sensing surface for said stopping of the belt conveyor upon belt rupturing or spillage.

A still further object of the present invention is directed to provide a belt rupture detection system which would help in saving large amount of financial loss due to damage and waste of conveyor belts used for raw material handling.

A still further object of the present invention is directed to provide a belt rupture detection system which would detect the occurrence of rupture in a reliable manner irrespective of size, shape and weight of steel scrap causing rupture in belt conveyors.

A still further object of the present invention is directed to provide a belt rupture detection system which would ensure uninterrupted steel production by consistent supply of raw materials to furnaces.

SUMMARY OF THE INVENTION

The basic aspect of the present invention is directed to a material conveyor belt rupture or spillage detection system comprising:
an idler supported with respect to stringer support of belt conveyors;
a collector connected to and disposed on one side of the idler and a lever disposed opposite to said collector;
a sensor means adapted to continuously sense the said lever position such that in case of belt rupture the material from the material carrying belt is collected in said collector which effects a counter upward motion of the lever and activate switching off of the conveyor.

A further aspect of the present invention is directed tom a material conveyor belt rupture or spillage detection system wherein counter weight on the lever is balanced such that the collector plate is always 20 degrees above the horizontal plane.

A still further aspect of the present invention is directed to a material conveyor belt rupture or spillage detection system wherein said sensor comprises an electrical sensor which is fixed with the conveyor stringer post.

Yet another aspect of the present invention is directed to a material conveyor belt rupture or spillage detection system wherein the upward motion of the lever is adapted to break the sensor circuit and thereby activates switching off of the conveyor.

A further aspect of the present invention is directed to a material conveyor belt rupture or spillage detection system wherein said sensor means operates on the principle of electromagnetic field in close surroundings of sensing surface for said stopping of the belt conveyor upon belt rupturing or spillage.

A still further aspect of the present invention is directed to a material conveyor belt rupture or spillage detection system wherein the presence of a metallic object (actuator) in the operating area causes dampening of the oscillation amplitude and the rise or fall of the oscillation is identified by a threshold circuitry to change the output of said sensor.

A still further aspect of the present invention is directed to a material conveyor belt rupture or spillage detection system wherein said sensor means comprises inductive proximity sensor and the sensor operating voltage is in the range of 5 to 60 volts DC with one NO and one NC contact.

A still further aspect of the present invention is directed to said material conveyor belt rupture or spillage detection system wherein said NO contact is wired to nearest pull chord switch of the conveyor which in turn is already operatively connected to PLC system for protection and the sensing face is continuously sensed by the operating striker.

A still further aspect of the present invention is directed to said material conveyor belt rupture or spillage detection system wherein said continuous sensing of object enables open contact and conveyor system tripping during cable cut, sensor damage or power failure.

The objectives and advantages of the present invention are described hereunder in greater details with reference to the following accompanying non limiting illustrative drawings.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1: is the schematic diagram of the belt rupture detection device according to the present invention showing the different components of the device.

Figure 2a & 2b: shows the photo graphic image of (a) the belt rupture detection device installed at site near to the conveyor and (b) the inductive proximity sensor to sense the operation of the lever attached to the device to detect possible belt rupture.

Figure 3a & 3b: is the schematic diagrams showing the complete span of conveyor belt running over rollers and the disposition of the belt rupture detection device and other components of the belt rupture detection system according to the present invention in relation to the conveyor along with location of central control room, PLC control and IO panel connected through cables.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING FIGURES

The present invention is directed to provide a belt rupture detection system in material handling which would detect occurrence of any rupture in belt immediately and stop the belt conveyor to generate alarm and initiate faster repair/maintenance thus would save large scale damage and waste of conveyor belts by early detection of rupture occurrence in belt.

The belt rupture detection system is a simple electro-mechanical system wherein a mechanical system operates a lever by collecting falling material from gap of a ruptured belt on a collector plate based on its weight based deflection and the lever deflection is sensed by a non contact type inductive proximity sensor and command is generated through PLC controller to stop the belt conveyor so that early repair can be undertaken thus minimizing damage/loss of costly conveyor belt.

Accompanying Figure 1 is the schematic diagram of the belt rupture detection device of the belt rupture detection system according to the present invention showing the different components of the device. The device involves a simple mechanical device that works on the principle of leverage. Whenever, there occurs a belt rupture, the material on the belt starts falling from the gap generated due to through cut in carrying side of the belt. The device collects this material and operates due to weight difference. The device is having a MS collector plate(1) and a lever(3) welded opposite to each other with a conveyor idler(2) located selectively in between the carrying side and return side of the conveyor belt(6) running on end rollers(5) and mounted on stringer support(7).The counter weight on the lever is balanced in such a way that collector plate(1) is always 20 degree above the horizontal plane. An electrical sensor(4) which is a inductive proximity sensor is fixed with the conveyor stringer(7) post such that it will always sense the lever position. As soon as material fall on the collector plate, it disturbs the balancing of the device and plate moves downward resulting in the upward motion of the lever. As the lever lifts, sensor circuit breaks and command goes to stop the belt conveyor. The device is placed as much as possible near to receiving chutes so that losses of belt length can be minimized. According to an aspect of the present invention, the belt rupture control device is also useful in detecting and preventing the material spillage due to belt sway, as the spillage materials also falls on the collector plate and by movement of the plate and lever, stops the conveyor.

Accompanying Figure 2a & 2b shows the photo graphic image of (a) the belt rupture detection device installed at site adjacent to the conveyor and (b) the inductive proximity sensor to sense the operation of the lever attached to the device to detect possible belt rupture. For detecting the belt rupture by sensing lever movement, a non contact type metal detector inductive proximity sensor is installed. It works on the principle of electromagnetic field in close surrounding of the sensing surface in order to stop the conveyor system during occurrence of belt rupturing. The presence of a metallic object (actuator) in the operating area causes a dampening of the oscillation amplitude. The rise or fall of such oscillation is identified by a threshold circuit that changes the output of sensor. The inductive proximity sensor installed is having a range of sensing distance of 40mm. The sensor operating voltage is in the range of 5 to 60 Volts DC with one NO and one NC contact.

Accompanying Figure 2(b) shows the inductive proximity sensor used in the belt rupture detection system according to the present invention which is of type NBN40-U1-Z2, M/s P & F make. The NO contact has been wired to nearest Pull Cord switch of conveyor which is already connected to PLC system for protection and the sensing face is continuously sensed by the operating striker as shown in Figure 2(a). The main advantage of continuous sensing of the object is that during cable cut, sensor damage or power failure, it will provide the open contact and conveyor system trips.

The inductive proximity sensor used in the system for detection of belt rupture is having the following specifications:
Switching element function:DC NO/NC;
Rated operating distance:40mm;
Installation:Non-flush;
Output polarity:DC: Assured operating distance: 0 -32.4mm;
Operating voltage:5 -60V DC;
Switching frequency f:0-100Hz;
Switching state indication:2 LED, yellow.

Accompanying Figure 3a & 3b is the schematic diagrams showing the complete span of conveyor belt running over rollers and the disposition of the belt rupture detection device and other components of the belt rupture detection system according to the present invention in relation to the conveyor along with location of central control room, PLC control and IO panel connected through cables. Components of the conveyor system and the cooperating belt rupture detection system installed thereon as can be seen in Figure 3a & 3b comprise the following:01-Idler Roller housing;02-Actuating plate;03-Actuator stopper;04-Extended lever;05-Balancing weight;06-Inductive proximity sensor;07-Pull cord switch;08-Pull rope; 09-Interlinking cable;10-Head roller;11-Receiving hopper;12-Tail roller;13-Rubber conveyor belt;14-Return supporting roller;15-Carrying supporting roller;16-Central Control room;17-Programable Logic Controller room;18-Remote I/O panel at nearest e-room;19-DH+/CONTRONET/PROFIBUS communication cable;20-Ethernet cable;21-Server Station;22-Operator Station;23-Ethernet Switch;24-Programable Logic Controller;25-Ethernet Bridge Module;26-DH+/CONTRONET/PROFIBUS communication Module;27-DH+/CONTRONET/PROFIBUS communication Scanner;28-Digital Output Module; and 29-Digital Input Module.

It can be found in Figures 3 a & 3 b, that the material handling conveyor belt(13) is running on Head Roller(10) at one end and the tail roller(12) at the other end. The Carrying supporting rollers(15) and the Return supporting roller(14) support the conveyor belt (13) from inside of carrying side and the return side of the belt respectively. The material conveyor belt rupture or spillage detection system according to the invention is installed on stringer support located in between the carrying side and the return side of the conveyor i.e. below the carrying side but above the return side. The location of the device is also near to the material receiving hopper/chute(11). The belt rupture/spillage device according to the present invention comprises an idler roller housing (01) mounted on stringer support. An Actuating/collector plate (02) is attached to one side of idler and a extending lever (04) is welded on opposite side of the idler roller. The arrangement is such that whenever material starts falling on the plate from any ruptured belt, the actuating plate moves down and the lever on the opposite side of idler moves upwards. An Actuator stopper (03) provides the required limit to movement of the actuating plate during operation. A Balancing weight(05) is attached to the actuating plate so that it normally remain at 20 degree upward from horizontal. An Inductive proximity sensor (06) is mounted on stringer support such that it can always sense the lever (04) movements of the device. The sensor(06) operating voltage is in the range of 5 to 60 Volts DC with one NO and one NC contact. The NO contact has been wired to nearest Pull Cord switch (07) of conveyor which is already connected to PLC system for protection and the sensing face is continuously sensed by the operating striker.

Generally 4 Nos. of Pull Cord Switches (07) is grouped in series and connected to Digital Input Module (29). The Sensor (06) is connected in series with this group for indication and remote interlocking. The Digital Input Module (29) is inserted in the Rack of Remote Input/output panel (18). In addition to Digital Input Module (29), Digital Output Module (28) and DH+/ControlNet/Profibus Communication Scanner (27) are installed in the Rack of Remote Input/output panel (18). The Remote Input / Output panel is connected to Plant Programmable Logic Controller (24) located in PLC room (17) through Communication (DH+/ControlNet/Profibus) cable (19). The Programmable Logic Controller (24) is having two communication modules i.e Ethernet Bridge Module (25) and DH+/ControlNet/Profibus Communication Module (26). Ethernet Bridge Module (25) is being connected to SCADA (Supervisory Control and Data Acquisition System) and Logical Programming at Central Control room (16). DH+/ControlNet/Profibus Communication Module (26) are connected to DH+/ControlNet/Profibus Communication Scanner (27) for exchange data between Programmable Logical Controller (24) to Remote Input Output system (18). At Central Control Room (16) the Programmable Logic Controller (24), Server Station (21) and Operator Station (22) are interlinked for data exchange by Ethernet Switch (23).

It is thus possible by way of the present invention to provide a material conveyor belt rupture or spillage detection system which is simple yet reliable for early detection of belt rupture/spillage and thus saving loss of expensive conveyor belts/materials. The system is capable to minimize upto 50% of belt cut length in a year which for an installed conveyor length of 237 meters at a cost of Rs 3,500 per meter, amounts to a saving of Rs 2.1 crores per year, justifying the importance of such a system and ensuring prospects of wide industrial application.
WE CLAIM:

1. A material conveyor belt rupture or spillage detection system comprising:
an idler supported with respect to stringer support of belt conveyors;
a collector connected to and disposed on one side of the idler and a lever disposed opposite to said collector;
a sensor means adapted to continuously sense the said lever position such that in case of belt rupture the material from the material carrying belt is collected in said collector which effects a counter upward motion of the lever and activate switching off of the conveyor.

2. A material conveyor belt rupture or spillage detection system as claimed in claim 1 wherein counter weight on the lever is balanced such that the collector plate is always 20 degrees above the horizontal plane.

3. A material conveyor belt rupture or spillage detection system as claimed in anyone of claims 1 or 2 wherein said sensor comprises an electrical sensor which is fixed with the conveyor stringer post.

4. A material conveyor belt rupture or spillage detection system as claimed in anyone of claims 1 to 3 wherein the upward motion of the lever is adapted to break the sensor circuit and thereby activates switching off of the conveyor.

5. A material conveyor belt rupture or spillage detection system as claimed in anyone of claims 1 to 4

wherein said sensor means operates on the principle of electromagnetic field in close surroundings of sensing surface for said stopping of the belt conveyor upon belt rupturing or spillage.

6. A material conveyor belt rupture or spillage detection system as claimed in anyone of claims 1 to 5 wherein the presence of a metallic object (actuator) in the operating area causes dampening of the oscillation amplitude and the rise or fall of the oscillation is identified by a threshold circuitry to change the output of said sensor.
7. A material conveyor belt rupture or spillage detection system as claimed in anyone of claims 1 to 6 wherein said sensor means comprises inductive proximity sensor and the sensor operating voltage is in the range of 5 to 60 volts DC with one NO and one NC contact.

8. A material conveyor belt rupture or spillage detection system as claimed in claim 7 wherein said NO contact is wired to nearest pull chord switch of the conveyor which in turn is already operatively connected to PLC system for protection and the sensing face is continuously sensed by the operating striker.

9. A material conveyor belt rupture or spillage detection system as claimed in claim 8 wherein said continuous sensing of object enables open contact and conveyor system tripping during cable cut, sensor damage or power failure.

Dated this the 18th day of July, 2014
Anjan Sen
Of Anjan Sen & Associates
(Applicants Agent)

ABSTRACT

TITLE: A MATERIAL CONVEYOR BELT RUPTURE OR SPILLAGE DETECTION SYSTEM.

The present invention relates to a material conveyor belt rupture or spillage detection system involving a simple electro-mechanical system which detects and avoids the rupture/spillage of conveyor belt for carrying raw materials in steel plant. The system works simply on principle of leverage wherein when the belt rupture initiates and material on the belt starts falling through gap, the device collects the material on a collector plate and operates due to weight difference. The collector plate and a lever are welded on opposite sides of a conveyor idler mounted on stringer support, such that when the collector plate collects material from a ruptured belt, it moves down and thereby operating the lever upwards and this movement is sensed by a noncontact type inductive proximity sensor and as the lever lifts, sensor circuit breaks and command goes to stop the belt conveyor before it is snapped avoiding large scale damage of conveyor belt.