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MANAGING CONVEYOR LIFE. WHAT IS A CONVEYOR TYPES OF CONVEYOR MAINTENANCE OF CONVEYOR OPTIMISATION TECHNIQUES. Benefits of Conveyor systems safely transport materials from one level to another, which when done by human labour would be strenuous and expensive.
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WHAT IS A CONVEYOR • TYPES OF CONVEYOR • MAINTENANCE OF CONVEYOR • OPTIMISATION TECHNIQUES
Benefits of Conveyor systems • safely transport materials from one level to another, which when done by human labour would be strenuous and expensive. • can be installed almost anywhere, and are much safer than using a forklift or other machine to move materials. • can move loads of all shapes, sizes and weights • variety of options available for running conveying systems, including the hydraulic, mechanical and fully automated systems, which are equipped to fit individual needs.
What is a conveyor? A conveyor moves material. A conveyor moves cardboard boxes, wood boxes, metal boxes and plastic boxes. Conveyors Can move materials by gravity or power. A conveyor can do more. It can move boxes UP against gravity . . . DOWN . . . or HORIZONTAL on a moving belt. The belt is moved by electric power. This is called a BELT CONVEYOR.
What is a belt conveyor? It is a machine with a moving BELT. The machine is made with these parts: A Bed This is a conveyor bed. It comes in many sizes-many lengths-many widths.
A pulley is like an iron pipe. Pulleys are put on each end of the bed. The pulleys are as wide as the "bed". Each pulley has a steel shaft through it. The shaft turns on a bearing . . . and the pulley turns with the shaft. A Pulley
When two pieces of steel touch each other; they cannot turn easily without bearings. Bearings use little steel balls to keep the pulley shaft and the conveyor bed from rubbing together. Now the shaft can turn easily. What is a bearing?
Pulley "A" is the drive pulley. Pulley "B" is the tail pulley. The drive pulley is usually larger because it does the work. The drive pulley is turned (driven) by a motor. A sprocket is put on the drive pulley shaft. A sprocket is put on the motor.
What is a Sprocket? A sprocket is a metal "wheel" with "teeth" on the outside.
How the drive pulley is "driven" A chain is put around the Drive Pulley Sprocket and the motor sprocket. The chain moves when the motor is started. The chain turns the drive pulley. But....
Because a motor turns very fast (1500 times per minute). . . A SPEED REDUCER must also be used. The SPEED REDUCER is put between the motor and the drive pulley.
. . . The motor is connected to the reducer with a V-Belt (like the fan belt in your car) or a "C" Face Coupling. The reducer is connected to the drive pulley with a chain . . . Now the Drive Pulley turns slower. All those parts (the motor, the speed reducer, and the drive pulley) are called:
The Conveyor Drive They must be put together to take up as little space as possible - so The motor and reducer are put under and within the conveyor BED. They must be put together to take up as little space as possible - so The motor and reducer are put under and within the conveyor BED.
But what about the tail pulley? The tail pulley is located at the tail end of the conveyor and it turns freely.
Now a "belt" can be put around the pulleys. The Drive Pulley turns and moves the belt around . . . and around . . . and around. BUT . . .
. . . it is dangerous to have the belt hang down under the conveyor bed - So small rollers are put into the Conveyor Bed to hold up the belt. These turn freely -- and just idle. They are called "Return Idlers". Some types of belts stretch more than others What to do?
1. Move the tail pulley! It can be moved to "take-up" the belt stretch. There are "take-up" screws onboth sides of the conveyor.Move these screws out slowly.Move them the same amount on both sides!This keeps the belt tight.
2.What do you do when the take-up screws are still all the way out - and the belt still stretches? Longer conveyors are provided with one or more short pieces of belt added, called a "dutchman" ·Remove the short pieces of belt. Now you can start the "take-up" procedure all over again. NOTE: If a "Dutchman" was not provided, you may need to add an UNDERSIDE TAKE-UP to your conveyor.
How to get more belt take-up There is more belt stretch on a long, long conveyor than the regular take-up and dutchman will give. So an "Underside Take-Up" should also be used. When should I use underside take-up? On conveyors 60' long, or more. NOTE: AN UNDERSIDE TAKE-UP is often used when the overall length of conveyor cannot be changed and the TAIL PULLEY "take-up" cannot be used.
BELT MOVES AT SPEED OF 20 MTR PER MINUTE This is best speed to move objects from one place to another. A person can walk about 4 miles per hour. If they were carrying a box they would walk much slower. Conveyors move boxes at about the same speed as a person carrying them. This is about 20 mtr per minute (or about 3/4 of a mile per hour).
A. The drive pulley is larger in the center than the ends. This helps keep the belt in the center. This is called a "Crown". B. The drive pulley is completely covered with vulcanized rubber. It is called "lagging". This keeps the pulley from slipping under the belt. PULLEY IS CROWNED AND LAGGED.
THE CONVEYOR DRIVE IS NORMALLY LOCATED AT THE END TO WHICH THE BELT MOVES. SO A DRIVE PULLEY "PULLS" THE BELT. NOTE: If the belt movement were reversed, the pulley would be pushing the belt. When the conveyor was fully loaded or when the belt stretched, the pulley could turn and not move the belt.
THE SNUB IDLER The Snub Idler is closer to the drive pulley.It makes the belt hug more of the drive pulley surface.The Snub Idler is ADJUSTABLE.It is ADJUSTABLE ON BOTH SIDES of the conveyor. (Each side of snub idler can be adjusted independently).Reason - The Snub Idler is used to steer the belt.
HHOW TO "STEER" THE BELT When belt runs forward and if it moves toward side "A" - move return idler nearest tail pulley on side "Y" toward "B". If belt moves toward side "B" - move return idler on side "X" toward "A". When belt runs in reverse and if it moves toward side "A" - move snub idler on side "X" toward "A". If belt moves toward side "B" - move snub idler on side "Y" toward "B".
CENTER DRIVE (Used with Horizontal Belt Conveyors) A. When belt movement is REVERSIBLE (on conveyors 40 ft. long or more) B. When overall length of conveyor cannot change (belt take up by tail pulley increases conveyor length) A center drive should be used because: ·Drive pulley now "pulls" belt in either direction Take-up pulley can now be used to take-up belt.
Skatewheel conveyors Consist of rows of small metal or aluminum wheels Does not use motors—gravity does all the work Best suited for bringing cartons, sacks and bags down a slope Helpful in shipping areas, moving items down certain lanes for loading into outbound trucks Hard to control the movement of products on these non-powered systems usually confined to short runs and accessible areas Cheap, low maintenance and often portable.
Wheels are put on axles. Aluminum spacer tubes are put on the axle between the wheels. This keeps wheels from moving from side to side on the axle. Skatewheel Conveyors
Belt conveyors A motor-powered belt atop a constructed bed Widely used in facilities because of their ability to cost-effectively move a wide array of products No problem conveying odd-shaped things and moving items up or down inclines because of the friction produced by the large surface contact area between belt and product Can carry light- and medium-weight goods Low-maintenance systems can transport products to almost any part of the warehouse.
Sliding bed conveyors • Should be considered if you have to move unstable loads slowly • Usually consist of an unpainted metal surface that slides along a bed • Excel in transporting odd-shaped products and small items that are not put into totes, because of the generous surface contact area between the solid bed and the product, these systems • Are commonly placed at load and assembly stations.
Live roller conveyors • Consist of elongated rollers placed across a conveying bed • Size of the rollers can be adjusted to accommodate the product being conveyed • Rollers are powered by belts, chains or line shafts. Often selected by facilities with many assorted products • Welcome heavy loads and thrive in dirty or harsh environments • However, they can only transport items with solid bottoms and of adequate weight. Loose, lightweight products can fall between the rollers and should thus be placed into boxes or totes.
ROLLER BED CONVEYORS When heavy total loads must be moved, it is best to use a conveyor bed with rollers (instead of regular conveyor bed). This is a Roller Bed belt conveyor Heavy total loads can be moved without using large motors when a ROLLER BED belt conveyor is used.
Pneumatic Conveyor Systems • Use of pipes or ducts called transportation lines that carry mixture of materials and a stream of high velocity air. • Materials are such as dry pulverised or free flowing or light powdery materials like cement, fly ash • Carrier systems simply push items from one entry point to one exit point, such as the money exchanging tubes used at a bank drive-thru window. • Dillute-phase systems use push/pull pressure to guide materials through various entry and/or exit points. • Suction or Vacuum systems, Pressure Type systems or a Combination systems
Accumulation systems Useful for work-in-process operations or ones that need a buffer Use rollers or belts that start and stop automatically to space cartons as directed by sensors Can back up and set specific items aside without holding up workflow Widely utilized at workstations and for preparing items before they get sorted More costly and need extra controls and motors. The added costs, however, can be recouped by the flexibility that these systems provide
What is a Gravity Conveyor? WHEELS OR . . . ROLLERS A gravity conveyor moves objects without motor power.
Long belt conveyors • Western Sahara:100 km long, from the phosphate mines of Bu Craa to the coast south of El-Aaiun. • Meghalaya in India to Sylhet in Bangladesh • Conveys limestone at 960 tph and shale from quarry in India to a cement factory in Bangladesh (7 km+ 10 km long) • Engineered by AUMUND France and L& T • Actuated by 3 synchronized drive units for a total power of about 1.8 MW • Manufactured in about 300 meter lengths on the Indian side and 500 meter lengths on the other side
To get the most out of your conveyor system, your maintenance practices should include far more than just emergency repairs. Maintenance, in general, affects all aspects of operational effectiveness and risks, not just system availability and cost — specifically safety, operational efficiency, energy efficiency, product quality, and environmental integrity.
From installation to retirement a comprehensive and important consideration from the day a system is conceived until the day it is retired from service. an essential activity for the achievement of optimum-return-on-investments a key to remaining competitive in a hyper-competitive world.
maintenance of conveyor systems divides into three broad categories: Predictive Preventive and corrective
Effective management of conveyor life begins with the selection of a system that matches the application for which it’s being used. Different applications require relatively different system components and configurations, especially as it applies to load requirements, operational conditions, cycles-of-use, materials conveyed, operational speeds, and usage period. When a conveyor system is improperly designed — i.e., oversized or undersized — value is wasted, regardless of the maintenance procedures employed.
For example, • drive motors that are undersized — relative to the loads being conveyed • Drive motors that are oversized • idlers with low quality components — such as frame, seals, and bearings • Pulleys that are underbuilt for the loads they are • Improperly designed impact areas • An under-built structure
Conveyor maintenance can and should be a straightforward, predictable process — not an emergency event. However, it can easily turn into one. The proper design of a conveyor system assures that power and loads are well balanced and that stress points are within controlled limits. The forces that occur at start-up and at stops can be quite surprising Proper system design is a must for protection of the equipment investment, system safety, system availability, ease-of-maintenance, as well as the long-term, value-producing capability of the entire operation.
Maintenance should only be performed with the conveyor system stopped and electrically locked out. check the entire conveyor for stray tools, parts, or other potential obstacles prior to restarting the system after maintenance activities have been preformed. Maintenance of a conveyor system is not a task for untrained or inexperienced individuals.
Predictive maintenance to eliminate surprises
Two basic types of predictive maintenance. replacing components at regularly scheduled intervals — usually during scheduled shutdowns — so that total failure of a component is avoided. Another to replace components as indicators of excessive wear or impending failure present themselves