Claims:We Claim:

1. A belt rupture protection system for material carrying conveyor belts wrapped over pulleys at driving and non driving end and having a forward and return side comprising,

an arm supporting a return side roller in contact with return side of the conveyor belt,

said arm with roller connected with hinged joint supported with respect to rigid frame support;

said return side roller adapted to rotate due to friction of return side of belt and said arm supporting the return side roller having a striker indicative of roller usual position in contact with said return side of conveyor belt ;

proximity sensor sensing said striker position continuously such that when a rupture takes place in the material carrying conveyor belt and material starts to fall on the return side conveyor through the ruptured portion, the return side roller supported with respect to said hinged arm is lifted due to the return side roller coming in contact with unwanted material on said return side of conveyor to shift disposition of the striker supported on said arm;

said sensor sensing such shift of disposition of said striker and cooperating with a PLC based unit to generate signal to stop the conveyor for rupture attending and any further rupture and material fall on the return side of conveyor.

2. A belt rupture protection system as claimed in claim 1 comprising,

said conveyor belt driven by a motor with gearbox at drive end pulley to provide linear motion of the belt wrapped over pulleys at driving and non driving end and having a forward and return side;

said device adapted to be mounted on a rigid frame support inbetween the gap of said forward and return side of said conveyor belt near discharge end of material from hopper having,

an arm supporting a roller in contact with return side of the conveyor belt,

said arm with roller connected with hinged joint with said frame support;

said arm roller rotates due to friction of return side of belt and holds a striker to its fixed position which is being sensed continuously by a proximity sensor such that when a rupture takes place in the material carrying conveyor belt and material starts to fall on the return side conveyor just below the ruptured portion, the roller with arm is lifted by rotating against the hinged support of the frame assembly to generate a signal by said sensor to stop the conveyor via a PLC to prevent further tearing and complete damage of said belt and enabling its early replacement.

3. A belt rupture protection system as claimed in claim 1 or 2 wherein during normal running, said motor along with gear box rotates the end pulley, and as pulley rotates, the wrapped belt conveyor starts moving in linear motion so that a fixed distance is maintained between the striker at its fixed position and said proximity sensor.

4. A belt rupture protection system as claimed in anyone of claims 1 to 3, wherein said lifting of hinged arm roller resulting in increasing of gap/distance between the striker and said proximity sensor, whereby the sensor trigger a switchable electrical signal which is being sensed by PLC for stopping the conveyor by withdrawing the run signal of conveyor drive motor.

5. A belt rupture protection system as claimed in anyone of claims 1 to 4, wherein said proximity sensor is an inductive proximity sensor that works on electromagnetic principle, its tip being a coil generating electromagnetic field, such that when any magnetic material such as the striker plate cut its magnetic field in vicinity of it, the sensor will generate an electrical signal which in turn is processed for controlling action through PLC or controller.

6. A belt rupture protection system as claimed in anyone of claims 1 to 5, wherein a shaft couple the drive pulley of belt conveyor with gear box of motor.

7. A belt rupture protection system as claimed in anyone of claims 1 to 6, wherein said conveyor belt is made up of rubber and threads used to transport the material from one location to others.

8. A method of rupture protection in conveyor systems and the like comprising:

providing a return side roller on the return side of the conveyor supported with respect to hinged arm;
said return side roller allowed to freely rotate based on the motion of the return side conveyor and contact of the return side roller to the same ;
sensing any change in the disposition of the return side roller with respect to its supporting arm in case of any conveyor rupture and material fall on the return side while under the return side roller; and
involving a PLC based cooperative unit to stop conveyor as and when any such change in the disposition of the return side roller with respect to its supporting arm arises to prevent further rupture and fall of material on the return side of the conveyor.

Dated this the 31st day of October, 2017
Anjan Sen
Of Anjan Sen & Associates
(Applicants Agent)

, Description:FIELD OF THE INVENTION

The present invention relates to a belt rupture protection system. More particularly, the present invention is directed to a belt rupture protection system installed on running conveyors for carrying hard and sharp lump materials from one stage to other stage for further processing for example in sinter plant in large steel plants, such that when a conveyor belt ruptures due to any foreign hard, sharp object stuck either in discharge point of hopper, hardly pressed on belt causing longitudinal tearing at any point and materials starts falling on return side of belt which is just below the rupture point, a proximity sensor trigger a switchable electrical signal which is being sensed by PLC which in turn stops the conveyor by withdrawing the run signal of conveyor resulting in stopping of belt and protecting from further tearing, and complete damaging of belt and spillage of material to surrounding area and reducing delay and down time of plant.

BACKGROUND OF THE INVENTION

Applicant’s Sinter plant consist of 148 number of belt conveyors. These conveyor belts are in series, which are interlocked with one another. These conveyors carry raw materials as well as finished sinter product. In normal running motor along with gear box rotates the end pulley, as pulley rotates, the wrapped belt conveyor starts moving in linear motion. The material stored in bunker/chute discharge the material in regulated way and material being conveyed from one location to another location.

In between the operation, if any hard /blunt object like, MS rod, plate, angles etc. stuck between the discharge chute of bunker and belt conveyor, will start tearing of belt as belt is already in linear motion. This tearing/rupturing of belt is so dangerous that it can tear the belt across its length resulting in huge break down, cost and material spillage. The adverse effects of a belt rupture in an operating plant are as follows:
a. The output at the discharge end of conveyor is less than the input material to the conveyor at the feeding end.
b. Belt gets damaged extensively beyond repair if runs with small rupture.
c. Require more time and manpower for housekeeping.
d. Less plant utilization and more delay time to replace conveyor belt.
e. Higher downtime and replacement costs.

Any damage to the belt leads to the stoppage of entire plant and spillage of huge materials. Replacement of belt is the only solution to start the plant in normal way which takes two much time(minimum 4 hrs for smaller belt length ) depend on belt length, its availability and preparedness. Also cleaning/disposing of fallen materials is also a tough and lengthy task which involved huge man power and time.

Earlier when conveyor belt used to rupture due to trapping of any hard object like, metal rod/plates/angle/channel or any hard object with sharp edge to discharge chute at tail end of the belt conveyor from were material falls for further transporting, its unable to transport the material(finished Sinter or raw material) as all carrying material getting fallen down through ruptured part of belt conveyor onto the floor which led to stoppage of plant and lot of material wastage. Normally no such device available for the case when any hard object like liner plate is part of the discharge hopper itself. In this case preventing of belt conveyor from rupturing is unavoidable.

So there was a persistent need for a complete solution to this problem of conveyor belt rupturing and consequent production and material loss.

OBJECTS OF THE INVENTION

The basic object of the present invention is directed to provide a belt rupture protection system for preventing conveyor Belt carrying hard and sharp materials from complete rupturing, which leads to plant stoppage and material spillage in that area.

A further object of the present invention is directed to a belt rupture protection system to avoid stoppage of entire plant and spillage of huge materials.

A still further object of the present invention is directed to a belt rupture protection system which would automatically stop any stretch of running conveyor carrying raw hard materials or sinters as soon as materials starts to fall through any small length of rupture portion at initial stage and prior to any large scale damage/material spillage has taken place so that it can be repaired or replaced and restored back in normal operation at earliest time.

SUMMARY OF THE INVENTION

The basic aspect of the present invention is directed to a belt rupture protection system for material carrying conveyor belts wrapped over pulleys at driving and non driving end and having a forward and return side comprising,

an arm supporting a return side roller in contact with return side of the conveyor belt,

said arm with roller connected with hinged joint supported with respect to rigid frame support;

said return side roller adapted to rotate due to friction of return side of belt and said arm supporting the return side roller having a striker indicative of roller usual position in contact with said return side of conveyor belt ;

proximity sensor sensing said striker position continuously such that when a rupture takes place in the material carrying conveyor belt and material starts to fall on the return side conveyor through the ruptured portion, the return side roller supported with respect to said hinged arm is lifted due to the return side roller coming in contact with unwanted material on said return side of conveyor to shift disposition of the striker supported on said arm;

said sensor sensing such shift of disposition of said striker and cooperating with a PLC based unit to generate signal to stop the conveyor for rupture attending and any further rupture and material fall on the return side of conveyor.

A further aspect of the present invention is directed to said belt rupture protection system comprising,

said conveyor belt driven by a motor with gearbox at drive end pulley to provide linear motion of the belt wrapped over pulleys at driving and non driving end and having a forward and return side;

said device adapted to be mounted on a rigid frame support in
between the gap of said forward and return side of said conveyor belt near discharge end of material from hopper having,

an arm supporting a roller in contact with return side of the conveyor belt,

said arm with roller connected with hinged joint with said frame support;

said arm roller rotates due to friction of return side of belt and holds a striker to its fixed position which is being sensed continuously by a proximity sensor such that when a rupture takes place in the material carrying conveyor belt and material starts to fall on the return side conveyor just below the ruptured portion, the roller with arm is lifted by rotating against the hinged support of the frame assembly to generate a signal by said sensor to stop the conveyor via a PLC to prevent further tearing and complete damage of said belt and enabling its early replacement.

A still further aspect of the present invention is directed to a belt rupture protection system wherein during normal running, said motor along with gear box rotates the end pulley, and as pulley rotates, the wrapped belt conveyor starts moving in linear motion so that a fixed distance is maintained between the striker at its fixed position and said proximity sensor.

Another aspect of the present invention is directed to said belt rupture protection system wherein said lifting of hinged arm roller resulting in increasing of gap/distance between the striker and said proximity sensor, whereby the sensor trigger a switchable electrical signal which is being sensed by PLC for stopping the conveyor by withdrawing the run signal of conveyor drive motor.

Yet another aspect of the present invention is directed to said belt rupture protection system wherein said proximity sensor is an inductive proximity sensor that works on electromagnetic principle, its tip being a coil generating electromagnetic field, such that when any magnetic material such as the striker plate cut its magnetic field in vicinity of it, the sensor will generate an electrical signal which in turn is processed for controlling action through PLC or controller.

A further aspect of the present invention is directed to a belt rupture protection system wherein a shaft couple the drive pulley of belt conveyor with gear box of motor.

A further aspect of the present invention is directed to a belt rupture protection system wherein said conveyor belt is made up of rubber and threads used to transport the material from one location to others.

A still further aspect of the present invention is directed to a method of rupture protection in conveyor systems and the like comprising:

providing a return side roller on the return side of the conveyor supported with respect to hinged arm;
said return side roller allowed to freely rotate based on the motion of the return side conveyor and contact of the return side roller to the same ;
sensing any change in the disposition of the return side roller with respect to its supporting arm in case of any conveyor rupture and material fall on the return side while under the return side roller; and
involving a PLC based cooperative unit to stop conveyor as and when any such change in the disposition of the return side roller with respect to its supporting arm arises to prevent further rupture and fall of material on the return side of the conveyor.

The above and other objects 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 illustration of the belt rupture protection device according to the present invention and its installation on a running conveyor belt carrying hard materials.
Figure 2 a & b: is the details of the belt rupture protection device according to present invention showing the principle of working of the device (a) at normal position and (b) when a small rupture takes place in the conveyor belt where it is installed and how the gap between the proximity sensor and striker is increased.
Figure 3: is the schematic block diagram of the control system involving sensor, PLC etc and its working in coordination with the device to stop the drive motor of conveyor as soon as a rupture takes place in any conveyor.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

The present invention is directed to provide a belt rupture protection system for preventing conveyor Belt carrying hard and sharp materials from complete rupturing, which leads to plant stoppage and material spillage in that area.

Accompanying Figure 1 shows a schematic illustration of the belt rupture protection system according to the present invention and its installation on a running conveyor belt carrying hard materials. The system comprise of the following components as would be evident from the illustrative embodiment shown in Figure 1:

The various components of the conveyor belt rupture protection system according to present invention and their functions are as follows:

1. Motor: Motor drives the belt conveyor duly coupled with gear box and shaft to drive pulley to transport the material from one location to other.
2. Shaft : Shaft used to couple the drive pulley of belt conveyor with gear box of motor.
3. Drive End Pulley : Drive end pulley drives the belt conveyor which is wrapped upon it.
4. Conveyor belt : Conveyor belt made up of rubber and threads used to transport the material from one location to others.
5. Striker :Its an MS plate, which is being sensed by inductive proximity switch mounted on fixed gap. Any position deflection in the sensing plate will result in change of gap of to sensor tips which ultimately gives and electrical signal as indication.
6. Sensor :Its an inductive proximity sensor which works on electromagnetic principle, its tip which is a coil actually generates electromagnetic field, any magnetic material e.g MS plate will cut its magnetic field when come in vicinity of it, as a result of it, the sensor will generate an electrical signal which in turn will be processed for controlling action through plc or controller.
7. Frame : Frame is the structure equipped with Arm, roller, hinge, mounting base, striker and sensor.
8. Roller : Roller is a cylindrical assemble mounted with bearings and small supporting shaft at both of its end. It rotates due to friction of returning side of belt’s linear motion.
9. Belt rupture : Belt rupture is a defect generated in belt by any foreign hard, sharp object stuck either in discharge point of hopper , hardly pressed on belt causing tearing of belt across the running length.
10. Non drive end pulley : Similar to drive end pulley this pulley is mounted at the receiving end of belt conveyor.
11. Chute/ Bunker : Bunker/chute is an intermediate temporary material storage kind of bin. This supply/deliver the material in controlled way to belt conveyor for its transportation to next location.

The working methodology of the system for belt rupture protection are described as per the following stages:

Normal process : In normal running, motor along with gear box rotates the drive end pulley. As pulley rotates, the wrapped belt conveyor starts moving in linear motion. The material stored in bunker/chute discharge the material in regulated way and material being conveyed from one location to another location.

Belt rupture device is mounted inbetween the gap of forward and return side of conveyor(4) near chute(11) at discharge end of material from hopper. The arm roller(8) of this device rotates due to friction of return side of conveyor belt(4) holds striker(5) to its fixed position which is being sensed continuously by inductive proximity sensor(6). This roller arm(8) is mounted through hinge to base frame(7) of the unit.

Rupturing of Belt conveyor : In between the operation if any hard /blunt object like, MS rod, plate, angles etc. stuck between the discharge chute(11) of bunker and belt conveyor(4) will start tearing of belt as the belt is already in linear motion. This tearing/rupturing of belt (4) is so dangerous that it can tear the belt across its length resulting in huge break down, cost and material spillage.

Control action : When belt(4) ruptures the conveying material starts falling on the return going belt which is just below the ruptured part. This fallen material starts moving towards return side of belt. As this material pass below the roller(8) and return side of material it lift the hinge frame(7). Lifting of hinged frame(7) resulting in increasing of gap/distance between striker(5) and inductive proximity sensor(6), hence sensor trigger a switchable electrical signal . As this signal being sensed by PLC(not shown) it stops the conveyor belt (4) by withdrawing the run signal of conveyor. Stopping of conveyor result in stopping of belt(4) from further tearing, ensuring protection from complete damaging of belt and spillage of material to surrounding area.

Accompanying Figure 2 shows in a detail view how the belt rupture protection device actually working where it is installed between forward and return side of conveyor near the material feeding bunker/chute(11) due to interference of striker(5) with fallen materials on return side of conveyor through a small rupture taken place in the conveyor belt and how the sensor is activated due to lifting of hinged frame(7) resulting in increasing of gap/distance between striker(5) and inductive proximity sensor(6).

Accompanying Figure 3 is the schematic block diagram of the control system involving sensor, PLC, belt drive motor etc and its working in coordination with the conveyor system to stop the drive motor of conveyor as soon as a rupture takes place in any conveyor and materials starts falling on the return side of conveyor wherein the control system has following components:

Proximity Sensor: It is a sensor which works as an electrical switch & gives output when a piece of metal (striker) will come in front of its sensing tips within a specified sensing distance.
Local Operating Station: It’s a box equipped with start and stop switches where wiring comes from motor control center and distributed to field equipment.
Relay Panel: This panel is equipped with number of relays with Normally open and normally close contacts. The signal from field or from PLC energizes its electromagnetic coil accordingly contacts makes and brakes which enables the devices of MCC or gives input information to PLC.
Digital Input to PLC: This is an electrical switchable signal. When it is high it enables PLC to perform certain tasks based on its programming.
Digital Output from PLC: This is an electrical Switchable signal. This signal becomes high based on programming of PLC. When it is high it enables power and control relays to energize/ de-energize accordingly motor / other electrical devices switched on / off.
Stop Command: This is an electrical signal from digital output of PLC, used to stop the motor (In this case motor of Belt conveyor).
In normal running, the distance between the proximity sensor and striker is less. After belt rupture, the distance between the striker and sensor increases thus leading to withdrawal of proximity signal. This signal flows through Local Operating Panel to relay panel thus giving an input to PLC. According to the program in the PLC, an alarm indication is flashed for rupture of the belt and stop command goes through the PLC to the motor of the conveyor.

It is thus possible by way of the present invention to provide a belt rupture protection device installed on running conveyors for carrying hard and sharp materials from one stage to other stage for further processing as in a sinter plant in large steel plants, wherein when a conveyor belt ruptures due to any foreign hard, sharp object stuck either in discharge point of hopper, hardly pressed on belt causing longitudinal tearing at any point and materials starts falling on return side of belt just below the rupture point, an inductive proximity sensor operatively trigger a switchable electrical signal which is being sensed by PLC which in turn stops the conveyor by withdrawing the run signal of conveyor thus protecting the belt from further tearing, and complete damaging of belt and spillage of material to surrounding area favouring reducing delay and down time of plant.