Belt Conveyor is a mechanical device that is used to transport bulk materials from one place to another. It is an endless belt operating system which is driven by a drive special arrangement, pulleys, and support rollers and with the help of this we can move bulk material from one location to another specific location. Basically, two types of belt conveyors are use in power plant/ Cement plants.
- Troughing Conveyor
- Pipe Conveyor
Troughing Conveyor: –
Troughing conveyor is carrying bulk material in a trough conveyor belt with the support of 35 or 45 Degree troughing idlers for use of high capacity and speed conveying of bulk material in the compression of flat conveyor. After transition distance conveyor belt form in a required trough angle in a caring zone.
Transition distance is a distance where belt forms in a regular angle from the Tail pulley and Head pulley.
Troughing angle basically design upon the size, surcharge angle of the material to be handle and the speed and the capacity of the conveyor systems.
Pipe Conveyor: –
Pipe conveyor is a kind of troughing conveyor itself. In this, the troughing conveyor folds and takes the shape of the pipe with the help of finger rollers and travels through the six-roller panel.
Pipe conveyor use and main advantages:
The pipe conveyor is safe to use, enviro-friendly and suitable for difficult layout. It is capable of handling almost all types of bulk materials. The pipe conveyor is also very reliable for long distance bulk material handling.
Main advantages of the Pipe conveyor:
- The pipe conveyor can be easily laid in horizontal and vertical curves.
- Pipe conveyors are also used for spillage free bulk material handling transportation.
- Pipe conveyors are also used for material handling at higher elevations.
- Due to its six-roller panel design, the pipe conveyor has less damage to the edge of the belt.
- The enclosed formation design of the belt in pipe conveyor ensures safe bulk material handling even in heavy rain and wind conditions.
- Pipe conveyor for long distance bulk material handling has a lower cost of installation than normal belt conveyor as the cost of transfer house is saved in easy left right movement.
Disadvantages of the Pipe conveyor:
- Due to the pipe shape formation in the pipe conveyors, a larger width of the belt is required than the troughing conveyors to handle the same material.
- Pipe conveyors have a lot of difficulty in the situation of oversize material and in overloading condition also.
- The pipe conveyor has difficulty in maintenance of belts and idlers.
- Pipe conveyors require more power than the same capacity of the troughing conveyors.
Main Component/ Parts of The Belt Conveyors: –
- Pulleys: A conveyor pulley is a mechanical device that gives direction and support to a conveyor belt.
- Idlers and idler frame: Idlers are a cylindrical roller that is fixed to a frame with the help of its shaft and provides drive support to the running belt with the required spacing.
- Drive arrangements: The drive arrangement is a part of the conveyor system that powers the conveyor to handle the material at the required speed and capacity. The drive unit mainly consists of a motor and a gearbox unit which is connected to the drive pulley of the conveyor with the help of couplings.
- Support Structures: Support structure is an important part of a conveyor system that provides rigid support to the conveyor. Such as stranger, post, conveyor gallery support, drive, and pulley support structures etc.
- Safety Protections devices/switches of the conveyors: Whenever a danger situation arises in the belt conveyor system, this safety equipment protects the equipment and the person from any danger to the conveyor system. There are some 07 safety devices which must be installed in the conveyor system.
- Pull cord Switches: In a conveyor belt system, pull cord switches are installed across the length on both sides of the belt and are connected by a wire rope. This allows to stop the conveyor belt by pull the rope from anywhere in the event of any abnormalities.
- Belt sway switches: In belt conveyor systems, belt sway switches are fitted to a required spacing across the length of both sides of the belt. If due to any reason the belt deviates from its path while moving, the sway switch on that side gets operated and the belt is stopped.
- Zero speed switch: In a belt conveyor system, the zero-speed switch is always mounted on a non-driving pulley. If due to any reason the belt slips while running, then there is a difference in the speed of non-drive and drive pulley and this switch is operated and the belt is closed.
- Hold back: A hold back or backstop in a belt conveyor system is a device that is attached to its drive arrangement that does not allow the belt to rotate in reverse direction. It is installed in all inclined conveyors so that whenever the belt conveyor is closed in load condition or no-load condition, the belt tries to rotate in reverse due to gravity, but holdback is never allow to rotate conveyor in reverse direction.
- Belt tear/ rip protection switches: In conveyor belt system, the tear detection switch is placed near the conveyor belt, which detects the tear or rip of the belt and stops the conveyor.
- Chute blockage switches: In conveyor belt system, chute blockage detection switch is installed on one side of the discharge chute which detects the chute blockage and stops the conveyor. By which the carrying material gets saved due to spillage.
- Plant warning siren: A warning siren is a device that must be installed in a conveyor system. Which gives us a warning before the system starts.
6. Dust Controlling System: Dust control system is a method and combination of device. Which controls the dust during the material movement in the belt. To control the dust in the belt conveyor system, it is necessary to install dust superaction and dust extraction system with proper sealing. By which dust is controlled at the time of transportation of bulk material.
- Conveyor Belt: In the conveyor system, the belt is the only part on which the bulk material is safely conveyed. The selection of conveyor belt is mainly done with the help of its strength, width, ply number, top cover, bottom cover, thickness, length and types of fabric and rubber grade.
- Belt cleaners/ Scrappers: A belt cleaner or scraper in a conveyor system is a device mounted on or immediately after the discharge pulley to clean the bulk material being conveyed after it is discharged.
- Counterweight Arrangement: The conveyor system is equipped with a counterweight arrangement to always maintain the required tension. In this, the weight is attached to the counterweight pulley with the help of counterweight structure. It is of both horizontal, vertical, and combined type according to the requirement of the system.
- Belt Foreign Material separator/ Detector: The conveyor system consists of a device for detecting and separating foreign materials for belt and equipment safety. It has an in-line magnetic separator which removes the ferrous material from the belt in running condition and there is another metal detector which detects both ferrous and nonferrous metal going into the conveyor belt and stop the belt immediately.
- Chutes and skirting: The conveyor system consists of a device for detecting and separating foreign materials for belt and equipment safety. It has an in-line magnetic separator which removes the ferrous material from the belt in running condition and there is another metal detector which detects both ferrous and nonferrous metal going into the conveyor belt and stop the belt. While receiving the material through chute skirting is protect the material to avoid spillage and dust emission around the system.
- Sample collection unit: This device is fitted in the conveyor system to collect the sample from the belt at the time of bulk material handling. From where the sample is prepared according to the required standard and sent to the lab for the result.
- Guards and Protections: Conveyor belt systems must have rotating equipment guards for protection. And according to the requirement, nip protection, net and handrail are installed.
- Gallery and hoods: Conveyor belt system has gallery on both sides for maintenance and observation and there is a hood for environment protection.
- Belt Weigher: Belt weigher is a device in a conveyor system by which we take the feed rate and weight of the material going on the belt at the time of bulk material handling.
- Conveyor interlockings: Interlocking is a type of logic to control in the conveyor system by which the belt operation is secured through PLC. And it does not allow to run the system to start in unhealthy conditions.
For the conveyor system to run safely and according to its requirement, no part or equipment should have been removed without valid permission, always insuring the availability of all safety equipment and interlockings from time to time.