Turnkey project A turnkey or a turnkey project (also spelled turn-key) is a type of project that is constructed so that it could be sold to any buyer as a completed product. This is contrasted with build to order, where the constructor builds an item to the buyer's exact specifications, or when an incomplete product is sold with the assumption that the buyer would complete it.Types of turnkey projects are Airport conveyors Baggage conveyors Belt conveyors Bucket conveyors Dispatch conveyors Drag conveyors Pivoted conveyors Screw conveyors Others Examples for turnkey projects Bucket conveyors

Bucket conveyors are used in carrying mineral or material from deep excavations

Baggage conveyor

Baggage conveyors are used to carry luggage from one place to another placeA turnkey project incorporates the following: Conveyor belt Idlers Pulleys OthersConveyor beltA conveyor belt is the carrying medium of a belt conveyor system (often shortened to belt conveyor). A belt conveyor system is one of many types of conveyor systems. A belt conveyor system consists of two or more pulleys (sometimes referred to as drums), with an endless loop of carrying mediumthe conveyor beltthat rotates about them. One or both of the pulleys are powered, moving the belt and the material on the belt forward. The powered pulley is called the drive pulley while the unpowered pulley is called the idler pulley. There are two main industrial classes of belt conveyors; Those in general material handling such as those moving boxes along inside a factory and bulk material handling such as those used to transport large volumes of resources and agricultural materials, such as grain, salt, coal, ore, sand, overburden and more.Today there are different types of conveyor belts that have been created for conveying different kinds of material available in PVC and rubber materials.The belt consists of one or more layers of material. Many belts in general material handling have two layers. An under layer of material to provide linear strength and shape called a carcass and an over layer called the cover. The carcass is often a woven fabric having a warp & weft. The most common carcass materials are polyester, nylon and cotton. The cover is often various rubber or plastic compounds specified by use of the belt. Covers can be made from more exotic materials for unusual applications such as silicone for heat or gum rubber when traction is essential.Material flowing over the belt may be weighed in transit using a beltweigher. Belts with regularly spaced partitions, known as elevator belts, are used for transporting loose materials up steep inclines. Belt Conveyors are used in self-unloading bulk freighters and in live bottom trucks. Belt conveyor technology is also used in conveyor transport such as moving sidewalks or escalators, as well as on many manufacturing assembly lines. Stores often have conveyor belts at the check-out counter to move shopping items. Ski areas also use conveyor belts to transport skiers up the hill.

Belt conveyor systemsConveyors are durable and reliable components used in automated distribution and warehousing.[2] In combination with computer controlled pallet handling equipment this allows for more efficient retail, wholesale, and manufacturing distribution. It is considered a labor saving system that allows large volumes to move rapidly through a process, allowing companies to ship or receive higher volumes with smaller storage space and with less labor expense.Rubber conveyor belts are commonly used to convey items with irregular bottom surfaces, small items that would fall in between rollers (e.g. a sushi conveyor bar), or bags of product that would sag between rollers. Belt conveyors are generally fairly similar in construction consisting of a metal frame with rollers at either end of a flat metal bed. The belt is looped around each of the rollers and when one of the rollers is powered (by an electrical motor) the belting slides across the solid metal frame bed, moving the product. In heavy use applications the beds which the belting is pulled over are replaced with rollers. The rollers allow weight to be conveyed as they reduce the amount of friction generated from the heavier loading on the belting. Belt conveyors can now be manufactured with curved sections which use tapered rollers and curved belting to convey products around a corner. These conveyor systems are commonly used in postal sorting offices and airport baggage handling systems. A sandwich belt conveyor uses two conveyor belts, face-to-face, to firmly contain the item being carried, making steep incline and even vertical-lift runs achievable.Belt conveyors are the most commonly used powered conveyors because they are the most versatile and the least expensive. Product is conveyed directly on the belt so both regular and irregular shaped objects, large or small, light and heavy, can be transported successfully. These conveyors should use only the highest quality premium belting products, which reduces belt stretch and results in less maintenance for tension adjustments. Belt conveyors can be used to transport product in a straight line or through changes in elevation or direction. In certain applications they can also be used for static accumulation or cartons.Long belt conveyorsThe longest belt conveyor system in the world is in Western Sahara. It is 98km (61mi) long, from the phosphate mines of Bu Craa to the coast south of El-Aaiun.[3]The longest conveyor system in an airport is the Dubai International Airport baggage handling system at 63km (39mi). It was installed by Siemens and commissioned in 2008, and has a combination of traditional belt conveyors and tray conveyors.[4]Boddington Bauxite Mine in Western Australia is officially recognised as having the world's longest and second-longest single belts with a 31-kilometre-long (19mi) belt feeding a 20km (12.5 miles) long belt. This system feeds bauxite through the difficult terrain of the Darling Ranges to the alumina refinery at Worsley. The longest single-belt international conveyor runs from Meghalaya in India to a cement factory at Chhatak Bangladesh.[5][6][7] It is about 17km long and conveys limestone and shale at 960 tons/hour, from the quarry in India to the cement factory (7km long in India and 10km long in Bangladesh). The conveyor was engineered by AUMUND France and Larsen & Toubro. The conveyor is actuated by three synchronized drive units for a total power of about 1.8MW supplied by ABB (two drives at the head end in Bangladesh and one drive at the tail end in India). The conveyor belt was manufactured in 300-meter lengths on the Indian side and 500-meter lengths on the Bangladesh side, and was installed on-site by NILOS India. The idlers, or rollers, of the system are unique[citation needed] in that they are designed to accommodate both horizontal and vertical curves along the terrain. Dedicated vehicles were designed for the maintenance of the conveyor, which is always at a minimum height of 5 metres (16ft) above the groundWhat is a conveyor belt?The belt conveyor is an endless belt moving over two end pulleys at fixed positions and used for transporting material horizontally or at an incline up or down. The main components of a belt conveyor are:The belt that forms the moving and supporting surface on which the conveyed material rides. It is the tractive element. The belt should be selected considering the material to be transported. The idlers, which form the supports for the carrying and return stands of the belt.The pulleys that support and move the belt and controls its tension.The drive that imparts power to one or more pulleys to move the belt and its loads.The structure that supports and maintains the alignments of the idlers and pulleys and support the driving machinery.Other components include:Loading chute or feeder chute that organizes the flow of material and directs it on the belt conveyor.Take-up-device which is used to maintain the proper tension of the belt for effective power transmission.Belt cleaner that keeps the belt free from materials sticking to the belt.Tramp removal device, which is optionally used in case the conveyed material bears the chance of having tramp iron mixed with it and subsequent handling of the material, demands its removal.Continuous weighing device for constantly measuring the load being carried by the conveyor belt.Discharge chutes to guide the discharged projectile to subsequent conveyor or other receiving point.Surge hopper and feeder, which is essential for supplying material to the conveyor at uniform rate when the supply of material is intermittent.Tripper arrangement to discharge material at different point or to other device.

ApplicationConveyor belts are widely used in mineral industry. Underground mine transport, opencast mine transport and processing plants deploy conveyor belts of different kinds to adopt the specific job requirements. The main advantages of conveyor belt system are:A wider range of material can be handled which pause problems in other transportation means. Belt conveyor can be used for abrasive, wet, dry, sticky or dirty material. The lump size of the transported material is limited by the width of the belt. Belts up to 2500 mm wide are used in mining industry.Higher capacity can be handled than any other form of conveyor at a considerably lower cost per tonne kilometre. Conveyor belts with capacity of 11000t/h and even higher can be deployed to match with higher capacity mining machinery.Longer distances can be covered more economically than any other transportation system. A single belt conveyor or a series of belt conveyors can do this. Belt conveyors can be adopted for cross-country laying.By the use of many forms of ancillary equipment such as mobile trippers or spreaders bulk material can be distributed and deposited whenever required.Many other functions can be performed with the basic conveying like weighing, sorting, picking, sampling, blending, spraying, cooling, drying etc.Structurally it is one of the lightest forms of conveying machine. It is comparatively cheaper and supporting structures can be used for many otherwise impossible structures such as crossing rivers, streets and valleys.The belt conveyor can be adopted for special purposes (fire resistant, wear resistant, corrosion resistant, high angle negotiation etc.) and can be integrated with other equipment.It can be horizontal, incline or decline or combination of all.Minimum labour is required for the operation and maintenance of belt conveyor system.In underground mine transport, belt conveyor can be used in thin seams as it eliminates the rock works that might otherwise be required to gain haulage height. Moreover, belt conveyor can provide continuous haulage service from pit bottom to the surface. Idlers IdlersIntroductionIdlers are an important component in any conveyor system as they are used to support the conveyor belt and the load carried on the belt.In a conveyor belt installation different types of idlers or roller supports are used. The idlers are required for proper support and protection of the belt and proper support of the load being conveyed.Idlers are designed with different diameters and are provided with antifriction bearings and seals, and are mounted on shafts. Frictional resistance of idlers influences the belt tension and consequently the power requirement. Idlers are mounted on a support frame, which can be shiftable or permanent. The carrying side of the belt is supported on the carrier rollers sets. A set of three rollers are arranged to form a trough for the troughed belt conveyor. The return side of the belt is supported on straight return idlers. The spacing of the idlers is determined based on the belt sag between the idlers. The sag depends on the belt tension, belt width, belt properties and the pay-load per meter of the belt. The idlers are specified by its length and diameter. These parameters are selected based on the required belt speed for the particular width of the belt.

There are a significant number of idlers on a conveyor and if the incorrect idlers are selected, the subsequent problem manifests itself along the entire conveyor length !Idlers are the 'low friction sliding surface' over which an endless conveyor belt is 'dragged' by the drive pulley(s), enabling a conveyor to operate for many thousands of hours without wearing out the belting. The selection of the correct type of idlers is very important with respect to the optimum load-carrying capacity of a conveyor and the environment in which the conveyor is to operate. Similarly, understanding the design of idlers, their limitations and the factors which affect their performance, is important in ensuring that the conveyor operates reliably and cost-effectively.Idler spacing will depend on a number of factors, i.e. layout, loads, rates of feed, belt tension. etc. Average troughing idler spacing for run of mine ore is in the vicinity of 1,2 meter. Return idler spacing is two to three times the troughing spacing

It has been stated above that there are basically two types of idlers namely, carrying and return idlers.Within these categories however, there are a number of different designs of idler sets which have developed as a result of particular applications, the need to minimise the stress imposed onto the belt and the environment in which the conveyor operates.These different types of idlers are described below, together with a different application for each.

Classification of idlersIdler TypeCEMA ClassRoll Diameterinches (mm)Classic IdlersBearing TypeRexDura IdlersBearing TypeBelt Widthinches (mm)

Light-dutyB4 (102)5 (127)RollerBall18 to 48 (457 to 1,219)

Medium-dutyCD5 (127)6 (152)

5 (127)6 (152RollerRollerBallBall18 to 60 (457 to 1,524)18 to 72 (457 to 1,829)

Heavy-dutyEF6 (152)7 (178)

7 (178)8 (203)BallBall36 to 96 (914 to 2,438)60 to 120 (1,524 to 3,048)

ClassificationDiameter (inches)Belt Width (Inch)Description

B4B54518 4818 48Light dutyLight Duty

C4C5C645618 6018 6024 60Medium DutyMedium DutyMedium Duty

D5D65624 7224 72Medium DutyMedium Duty

E6E76736 9636 96Heavy DutyHeavy Duty

TYPES OF IDLERSCarrying Idlers (Troughing or Flat)Support the belt in the section of the conveyor that transports the material. These idlersmay be flat or troughed to shape the belt to prevent spillage and are available in 20, 35and 45 trough angles with equal or unequal roll lengths. Normal spacing is 3 to 5 feet.

Impact Idlers (Troughing or Flat)Prevent damage to the belt at the loading point. These idlers may be troughing or flattypes with grooved, molded rubber rolls. It is standard practice to use impact idlers at allloading and transfer points when the impact force exceeds 40 foot-pounds.To ensure maximum belt protection for optimum life and to reduce skirtboard leakage, theimpact idlers should be at least six-inch diameter and spaced at one-foot intervals

Return IdlersSupport the empty belt between the discharge point and the tail pulley. Normal spacingis 10 feet.a.Steel Used where materials are not sticky, corrosive or abrasive. Availablewith urethane covering. Six-inch diameter also available in 1/4" wall thickness.

b.Spiral Used where sticky materials adhere to the belt, where a corrosiveenvironment is present or abrasive wear is a problem. Unique constructionminimizes belt fleet and damage to the return belt due to material buildup onthe idler rolls. Spiral roll idlers can be used for belt travel in one direction only.

c.Disc Used under the same conditions as the spiral idler. These idlerscan be used for belt travel in either direction. Massed end discs are standard.Ceramic, urethane and rubber disc rolls available

Carrying Belt Training Idlers (Troughing or Flat)Assist in keeping the belt centered on the conveyor. Actuating shoe type is used on belttraveling in either direction. Positive type is used on belt traveling in one direction onlyand is illustrated. Normal spacing is 100 feet and not within 50 feet of the head or tailpulley.(Urethane rolls enhance trainer effectiveness.)

Return Belt Training IdlersUsed for the same purposes as are carrying training idlers. They are of the actuating shoetype, belt travel either direction, and the positive belt travel one direction only. Thepositive type is illustrated. Normal spacing is 100 feet and not within 50 feet of the heador tail pulley.(Urethane rolls enhance trainer effectiveness.)Can also be furnished with spiral or disc rolls.

Figure 7 Components of belt conveyor

Fixed carrying idler

Fixed impact idler

Idler spacingBelt Width (inches)Troughed Idler SpacingWeigh of Material Handled (lbs/cu ft)Return Idler

305075100150200

1824305.55.05.05.04.54.55.04.54.55.04.04.04.54.04.04.54.04.010.010.010.0

3642485.04.54.54.54.54.04.04.04.04.03.53.53.53.03.03.53.03.010.010.010.0

5460724.54.04.04.04.03.53.53.53.53.53.03.03.03.02.53.03.02.510.010.08.0

84963.53.53.53.53.03.02.52.52.52.02.02.08.08.0

PulleyA conveyor belt system uses different types of pulleys like end pulley, snub pulley, bend pulley etc. as shown in the Figure 3. The end pulleys are used for driving and sometimes for making tensioning arrangements. Snub pulleys increase the angle of wrap thereby increasing the effective tension in the belt. The pulley diameter depends on the belt width and belt speed.Pulleys are used for providing the drive to the belt as well as for maintaining the proper tension to the belt. Minimum transition distance as shown in Table 4 should be followed while placing idlers in front of pulleys.Power is given to the pulleys in a conveyor belt.There are two types of pulleys 1> head pulley, which is adjusted at top of a inclined belt 2>tail pulley, which is adjusted at bottom of a belt

Conveyor belts used in coal mines:Coal occupies a central position in modern human endeavors. Last year over 7000 megatons were mined worldwide. Powerful, yet dirty and dangerous, use of coal is expanding every year, with 2010 witnessing a production increase of 6.8%. Around 70 countries have recoverable reserves, which some estimates claim will last for over a hundred years at current production levels. Mining for coal is one of the world's most dangerous jobs. While deadliest in China, where thousands of miners die annually, the profession is still hazardous in the West and other regions as well. Our mining and use of coal accounts for a variety of environmental hazards, including the production of more CO2 than any other source. Other concerns include acid rain, groundwater contamination, respiratory issues, and the waste products which contain heavy metals. But our lives as lived today rely heavily on the combustible sedimentary rock. Over 40% of the world's electricity is generated by burning coal, more than from any other source. Chances are that a significant percentage of the electricity you're using to read this blog was generated by burning coal. Gathered here are images of coal extraction, transportation, and the impact on environment and society.By incorporating a conveyor belt in coal mines, there is a drastically reduction in man power and time consumption.

Manufacturing of idlers for conveyors beltsManufacturing of idlers involves different processThere is a company called hi-tec hydraulic engineers at cherlapally phase-5, which manufacture idlersDifferent types of idlers manufactured by this company are: Carriage idlers Return idlers Impact idlers Guide returnsThe processes involving in manufacturing areCUTTINGIn this process M.I (mild steel) pipe of required diameter is selected and it is placed against the cnc cutting machine, which cuts mild steel pipe with required dimensions.Required dimensions are to be included in the programme of the cnc cutting machine.

Mild steel pipecnc cutting machine consists of the circular saw blade , which rotates inside the machine with the help of a motor HSS Metal cutting circular saw blades are offered in 4 different quality levels: HSS-DMo5 for cutting mild steel up to 500 N/mm2. HSS-DMo5 KX-COATED for cutting mild steel up to 800N/mm2 and for stainless steel. HSS-Co Cobalt for cutting stainless steel. HSS-DMo5 KX-COATED + CHIP BREAKER for cutting mild steel up to 800/N/mm2Length of the roller should be entered in the cnc cutting machine, then machine automatically adjust the long pipe after each cutting. After cutting M.S pipes of different sizesSimilarly shafts are also cutted with required lengths in a cnc cutting machineMaterial of shafts is mild steel bright bar.

BORINGBoring is the process of enlarging a hole that has already been drilled (or cast), by means of a single-point cutting tool (or of a boring head containing several such tools), for example as in boring a gun barrel or an engine cylinder. Boring is used to achieve greater accuracy of the diameter of a hole, and can be used to cut a tapered hole. Boring can be viewed as the internal-diameter counterpart to turning, which cuts external diameters.After cutting, boring has to be done so that iron housings at both ends can be incorporated to the roller.For any idlers , boring machine can bore upto 9mm,so that housing can be fitted properlyWELDINGAfter boring, MIG welding has to be done to the housing cap and to the roller.MIG welding consumes a mild steel copper coated wire and co2 gas to produce a permanent joint.Gas metal arc welding (GMAW), sometimes referred to by its subtypes metal inert gas (MIG) welding or metal active gas (MAG) welding, is a welding process in which an electric arc forms between a consumable wire electrode and the workpiece metal(s), which heats the workpiece metal(s), causing them to melt, and join.Along with the wire electrode, a shielding gas feeds through the welding gun, which shields the process from contaminants in the air. The process can be semi-automatic or automatic. A constant voltage, direct current power source is most commonly used with GMAW, but constant current systems, as well as alternating current, can be used. There are four primary methods of metal transfer in GMAW, called globular, short-circuiting, spray, and pulsed-spray, each of which has distinct properties and corresponding advantages and limitations.Originally developed for welding aluminum and other non-ferrous materials in the 1940s, GMAW was soon applied to steels because it provided faster welding time compared to other welding processes. The cost of inert gas limited its use in steels until several years later, when the use of semi-inert gases such as carbon dioxide became common. Further developments during the 1950s and 1960s gave the process more versatility and as a result, it became a highly used industrial process. Today, GMAW is the most common industrial welding process, preferred for its versatility, speed and the relative ease of adapting the process to robotic automation. Unlike welding processes that do not employ a shielding gas, such as shielded metal arc welding, it is rarely used outdoors or in other areas of air volatility. A related process, flux cored arc welding, often does not use a shielding gas, but instead employs an electrode wire that is hollow and filled with flux. Milling, turning and slotingShaft is moved for milling process, turning process and two slots are made on the shaft.Milling is the machining process of using rotary cutters to remove material[1] from a workpiece advancing (or feeding) in a direction at an angle with the axis of the tool.[2][3] It covers a wide variety of different operations and machines, on scales from small individual parts to large, heavy-duty gang milling operations. It is one of the most commonly used processes in industry and machine shops today for machining parts to precise sizes and shapes. Turning is an engineering machining process in which a cutting tool, typically a non-rotary tool bit, describes a helical toolpath by moving more or less linearly while the workpiece rotates. The tool's axes of movement may be literally a straight line, or they may be along some set of curves or angles, but they are essentially linear (in the nonmathematical sense). Usually the term "turning" is reserved for the generation of external surfaces by this cutting action, whereas this same essential cutting action when applied to internal surfaces (that is, holes, of one kind or another) is called "boring". Thus the phrase "turning and boring" categorizes the larger family of (essentially similar) processes.Slotting is a machining process used to cut short, straight features into a work piece. Slotters can be a dedicated machine or an attachment to a conventional milling machine. A slotting machine will usually use some sort of form tool to cut features such as internal keyways, splines and internal gear teeth.Here capstan and turret lathe is used to perform both turning and slotting, so that work piece is in stationary position and cutting tool is in rotary position.This lathe is provided with 3 servo motors and a D.C motor.Cutting of edges of the shaft are done by cnc milling machine, in milling machine both work piece and cutting tool rotates at a time so that two cuttings takes place at a time at each end.It is also provided with servo motors.ASSEMBLINGIn this process, assembling of roller and shaft takes place by attaching some others products in between roller and shaft.Others products include Nylon cap Cyr clip Ball bearing Labyrinth seal female Labyrinth seal-male Cyr clip Nylon cap Dust cap Grease is to be placed in between labyrinth seal female and labyrinth seal male.

PAINTINGIn painting first roller is coated with premier and it is allowed to dry for some time.After the premier is dried it is coated with final coating with a paint of companys preference.

Carriage idlerIdler after manufacturing is placed in frame for the proper arrangement of belt conveyor.

Frame for idlers

Carriage idlersImpact idlersA special rubber ring is arranged on the roller to sustain the impacts due to sudden loads.

Impact idlers