CHAPTER -1

INTRODUCTION

CENTRIFUGAL PUMP The operating manual of any centrifugal pump often starts with a general statement. Your centrifugal pump will give you completely trouble free and satisfactory service only on the condition that it is installed and operated with due care and is properly maintained. Despite all the care in operation and maintenance, engineers often face the statement the pump has failed i.e. it can no longer be kept in service inability to deliver the desired flow and bead is just one of the most common conditions for taking a pump out of service. There is other many conditions in which a pump, despite suffering no loss in flow or head, is considered to have failed and has to be pulled out of service as soon as possible. These include seal related problems (leakages, loss of flushing. cooling, quenching systems. etc), pump and motor bearings related problems (loss of lubrication. cooling, contamination of oil, abnormal noise, dc), leakages from pump casing, very high noise and vibration levels, or driver (motor or turbine) related problems. The list of pump failure conditions mentioned above is neither exhaustive nor are the conditions mutually exclusive. Often the root causes of failure arc the sant but the symptoms are different. A little care when first symptom of a problem appears can save the pumps from permanent failures. Thus the most important task in such situations is to tend out whether the pump has failed mechanical or if there is some process deficiency or both many times when the pumps arc sent to the workshop. The maintenance people do not find anything wrong on disassembling it. Thus the decision to pull a pump out of service for maintenance / repair should he made after a detailed analysis of the symptoms and root causes of the pump failure. Also in case of any mechanical failure or physical damage of pump internals, the operating engineer should be able to relate the failure to the process units operating problems. Any operating engineer, who typically has a chemical engineering background and who desires to protect his pumps from frequent failures must develop not only a good understanding of the process but also thorough knowledge of the mechanics of the pump. Effective troubleshooting requires an ability to observe changes in performance over time, and in the event of a failure, the capacity to thoroughly investigate the cause of the failure and take measures to prevent the problem from Ye occurring. The fact of the matter is that there are three types of problems mostly encountered with centrifugal pumps:-1. Design errors2. Poor operation3. Poor maintenance practice 1.2 WORKING MECHANISM OF A CENTRIFUGAL PUMP

A centrifugal pump is one of the simplest pieces of equipment in any process plant. Its purpose is to convert energy of a prime mover (an electric motor or turbine) first into velocity or kinetic energy and then into pressure energy of a fluid that is being pumped. The energy changes occur by virtue of two main pans of the pump, the impeller and the volute or diffuser. The impeller is the rotating pan that converts driver energy into the kinetic energy. The volute or diffuser is the stationary part that convenes the kinetic energy into pressure energy.

GENERATION OF CENTRIFUGAL FORCE- The process liquid enters the suction nozzle and then into eye (center) of a revolving device known as an impeller. When the impeller rotates it spins the liquid sitting in the cavities between the vanes outward and provides centrifugal acceleration. As liquid leaves the eye of the impeller a low pressure area is created causing more liquid to flow toward the inlet. Because the impeller blades are curved the fluid is pushed in a tangential and radial direction by the centrifugal force. This force acting inside the pump is the same one that keeps water inside a bucket that is rotating at the end of a string Figure-1 Working of centrifugal pump

1.3 CONVERSION OF KINETIC ENERGY TO PRESSURE ENERGY-

The key idea is that the energy created by the centrifugal force is kinetic energy. The amount of energy given to the liquid is proportional to the velocity at the edge or vane tip of the impeller. The faster the impeller revolves or the bigger the impeller is, then the higher will be the velocity of the liquid at the vane tip and the greater the energy imparted to the liquid. This kinetic energy of a liquid coming out of an impeller is harnessed by creating a resistance to the flow. The first resistance is created by the pump volute (casing) that catches the liquid and slows it down. In the discharge nozzle, the liquid further decelerates and its velocity is converted to pressure according to Bernoullis principle. Therefore, the head (pressure in terms of height of liquid) developed is approximately equal to the velocity energy at the periphery of the impeller expressed by the following well-known formula:

H=V2/2g

Where, H=Total head developed in feet V=Velocity at periphery of impeller in feet/sec G= Acceleration due to gravity-32.2 feet/sec2

A handy formula for peripheral velocity is:V=Nxd/229Where, v=Velocity at periphery of impeller N=The impeller RPM (revolution per minute) D=Impeller diameter in inches This head can also be calculated from the readings on the pressure gauges attached to the suction and discharge lines.

1.4 GENERAL COMPONENTS OF CENTRIFUGAL PUMPS A centrifugal pump has two main components: A rotating component comprised of an impeller and a shaft A stationary component comprised of a casing, casing cover and bearings. The main components are discussed in brief below.

1.5 STATIONARY COMPONENTS CASING Casings are generally of two types: volute and circular. The impellers arc fitted inside the casings.

VOLUTE CASINGS It builds a higher head: circular casings are used for low head and high capacity. A volute is a curved funnel increasing in area to the discharge port. As the area of the cross-section increases the volute reduces the speed of the liquid and increases the pressure of the liquid. One of the main purposes of a volute casing is to help balance the hydraulic pressure of the shaft of the pump However; this occur basic at the manufacturers recommended capacity. Running values style pumps at a lower capacity than the manufacturer recommends can put lateral stress on the shaft of the pump, increasing wear-and-tear on (he seals and bearings, and on the shaft itself. Double-volute casings are used when the radial thrusts become significant at reduced capacities. Figure-2 Volute Casing

CIRCULAR CASING- These have stationary diffusion vanes surrounding the impeller periphery that convert velocity energy to pressure energy. Conventionally, the diffusers are applied to multi-stage pumps. The casings can be designed either as solid casings or split casings. Solid casing- It implies a design in which the entire casing including the discharge nozzle is all contained in one casting or fabricated piece.

SPLIT CASING- It implies two or more parts are fastened together. When the casing parts arc divided by horizontal plane, the casing is described as horizontally split or axially split casing. When the split is in a vertical plane perpendicular to the rotation axis, the casing is described as vertically split or radically split casing. Casing Wear rings act as the seal between the casing and the impeller.

1.6 SUCTION AND DISCHARGE NOZZLE-

The suction and discharge nozzles are part of the casings itself. They commonly have the following configurations.

END SUCTION /TOP DISCHARGE The suction nozzle is located at the end of, and concentric to, the shaft while the discharge nozzle is located at the top of the case perpendicular to the shaft. This pump is always of an overhung type and typically has lower NPSHr because the liquid feeds directly into the impe1lerye.

TOP SUCTION /TOP DISCHARGE NOZZLE The suction and discharge nozzles are located at the top of the case perpendicular to the shaft. This pump can either be an overhung type or between-bearing type twit is always a radials split case pump. Side suction or Side discharge nozzles - The suction and discharge nozzles are located at the sides.

1.7 SEAL CHAMBER AND STUFFING BOX-

Seal chamber and Stuffing box both refer to a chamber, either integral with or separate from the pump case housing that forms the region between the shaft and casing where sealing media are installed. When the sealing is achieved by means of a mechanical seal, the chamber is commonly referred to as a Seal Chamber. When the sealing is achieved by means of packing the chamber is referred to as a Stuffing Box. Both the seal chamber and the stuffing box have the primary function of protecting the pump against leakage at the point where the shaft passes out through the pump pressure casing. When the pressure at the bottom of the chamber is below atmospheric it prevents air leakage into the pump. When the pressure is above atmospheric the chambers prevent liquid leakage out of the pump. The seal chambers and stuffing boxes arc also provided with cooling or heating arrangement for proper temperature control. An externally mounted seal chamber and its parts.

GLAND- The gland is a very important part of the seal chamber or the stuffing box. Ii gives the pickings or the mechanical seal the desired fit on the shaft sleeve. It can be easily adjusted in axial direction. The gland comprises of the seal hush, quench, cooling, drain, and vent connection polls as per the standard codes like API 682.

THROAT BUSHING- The bottom or inside end of the chamber is provided with a Stationary device called throat bushing that forms a restrictive close clearance around the sleeve (or shaft) between the seal and the impeller. Throttle bushing refers to a device that forms a restrictive close clearance around the sleeve (or shaft) at the outboard end of a mechanical seal gland. Internal circulating device refers to device located in the seal chamber to circulate seal chamber fluid through a cooler on barrier/buffer fluid reservoir. Usually it is referred to as a pumping ring.

1.8 BEARING HOUSING-The bearing housing encloses the bearings mounted on the shaft. The bearings keep the shaft or rotor in correct alignment with the stationary parts under the action of radial and transverse loads. The bearing house also includes an oil reservoir for lubrication, constant level oiler, jacket for cooling by circulating cooling water.

1.9 ROTATING COMPONENTS IMPELLER- The impeller is the main rotating part that provides the centrifugal acceleration to the fluid. They are often classified in many ways. Based on major direction of flow in reference to the axis of rotation- a) Radial flow b) Axial flow c) Mixed flow

Based on suction type- a)Single-suction: liquid inlet on one side b) Double-suction: liquid inlet to the impeller symmetrically from both sides. Based on mechanical construction- a) Closed: shrouds or sidewall enclosing the vanesb) Open: no shrouds or wall to enclose the vanesc) Semi-open or vortex type

Figure-3 Impeller Closed impellers require wear rings and these wear rings present another maintenance problem. Open and semi-open impellers are less likely to clog, but need manual adjustment to the volute or back-plate to get the proper impeller setting and prevent internal re-circulation. Vortex pump impellers arc great for solids and string materials but they are up to 50% less efficient than Conventional designs. The number of impellers determines the number of stages of the pump. A single stage pump has one impeller only and is best for low head service. A two-stage pump has two impellers in series for medium head service. WEAR RINGS- Wear ring provides an easily and economically renewable leakage joint between the impeller and the casing clearance becomes too large the pump efficiency will be lowered causing heat and vibration problems. Most manufacturers require that you disassemble the pump to check the wear ring clearance and replace the rings when this clearance doubles.

1.9.2 SHAFT- The basic purpose of a centrifugal pump shall is to transmit the torques encountered when starting and during operation while supporting the impeller and other rotating pails. It must do this job with a deflection less than the minimum clearance between the relating and stationary parts. Pump shafts arc usually protected from erosion, corrosion, and wear at the seal chambers, leakage Joints, internal bearings, and in the waterways renewable sleeves. Unless otherwise specified, a shaft sleeve of wear, corrosion, and erosion resistant material shall be pros added to protect the shaft. The sleeve shall be scaled at one end. The shaft sleeve assembly shall extend beyond the outer face of the seal gland plate. (Leakage between the shaft and the sleeve should not be confused with leakage through the mechanical seal). Figure-4 Shaft Sleeve

1.10 AUXILIARY COMPONENTS Auxiliary components generally include the for the following services: a. Seal flushing , cooling, quenching systems b. Seal drains and vents c. Bearing lubrication , cooling system d. Seal chamber or stuffing box cooling, heating systems c. Pump pedestal cooling systems Auxiliary piping systems include tubing, piping, isolating valves, control valves, relief valves, temperature gauges and thermocouples, pressure gauges, sight flow indicators, orifices, seal flush coolers, dual seal barrier/buffer fluid reservoirs, and all related events and drains. All auxiliary components shall comply with the requirements as per standard codes like API 610 (refinery services), API 682 (shaft sealing systems) etc.

1.11 DEFINITION OF IMPORTANT TERMS-The key performance parameters of centrifugal pump are IP (Brake horse power) EP (Best efficiency point) and specific speed. The pumps provide the operating window within which these parameters can be varied for satisfactory pump operation. The following parameters or terms are discussed in detail in this section- 1. Capacity 2. Head3. NPSH Net Positive Suction Head required NPSHr Net Positive Suction Head available NPSHU 4. Power (Brake Horse Power and B.H.P) and Efficiency (Best Efficiency Point, B.E.P) 5. Specific Speed (Ns) 6. Affinity Laws

1.11.1 CAPACITY- Capacity means the flow rate with which liquid % moved or pushed 4Ij1esircd point in the process. It is commonly measures in either gallon per minute or cubic meter per hour. The capacity usually changes with the changes in one rotation for the process. For example, a boiler feed pump is an application that needs a constant pressure with varying capacities to meet a changing steam demand.

1.11.2 HEAD-

Significance of using the head term instead of the pressure term the pressure at any point in a liquid can be thought of as being caused by a vertical column of the liquid due to its weight. The height of this column is called the static head and is expressed in terms of feet of liquid. The same head term is used to measure the kinetic energy created by the pump. In other words, head is a measurement of the height of a liquid column that the pump could create from the kinetic energy imparted to the liquid. Imagine a pipe shooting a jet of water straight up into the, air, the height the water goes up would be the head. The head is not equivalent to pressure. Head is a term that has units of a length or feet and pressure has units of force per unit area or pound pew square inch.

Note: The Subscription refers to suction conditions and d refers to discharge conditions. Significance of using Head instead of Pressure Pressure to Head Conversion formula Static Suction Head, Static Discharge Head Friction Head Vapor pressure Pressure Velocity head Total Discharge head Total Differential Head

STATIC SUCTION HEAD ( hs )-Head resulting from elevation of the liquid relative to the pump center line. If the liquid level is above pump centerline. hS positive, lithe liquid level is below pump centerline, hS are negative. Negative hS condition is commonly denoted as a suction lift condition.

STATIC DISCHARGE HEAD (HD)It is the vertical distance in feet between the pump center line and the point of free discharge or the surface of the liquid in discharge tank.

FRICTION HEAD (HF): The head required to overcome the resistance to flow in the pipe and fittings. It is dependent upon the size, condition and type of pipe, number and type of pipe fittings, flow rate, and nature of the liquid.

VAPOR PRESSURE HEAD(HVP ): Vapor pressure is the pressure at which a liquid and its vapor co-exist in equilibrium at a given temperature. The vapor pressure of liquid can be obtained from vapor pressure tables. When the vapor pressure is converted to head, it is referred to as vapor pressure head. The value of vapor pressure head of a liquid increases with the rising temperature and effect, opposes the pressure on the liquid surface, the positive force that tends to cause liquid flow into the pump suction i.e. it reduces the suction pressure head.

PRESSURE HEAD (hp): Pressure Head must be considered when a pumping system either begins or terminates in a tank which is under some pressure other than atmospheric. The pressure in such a tank must first be converted to feet of liquid. Denoted as hp, pressure head refers to absolute pressure on the surface of the liquid reservoir supplying the pump Suction, converted to feet of head. If the system is open, equals atmospheric pressure head. VELOCITY HEAD (hv): Refers to the energy of a liquid as a result of its motion at some velocity . It is the equivalent head in feet through which the water would have to fall to acquire the same velocity, or in other words, the head necessary to accelerate the water. The velocity head is usually insignificant and can be ignored in most high head systems. However, it can be a large factor and must be considered in low head systems.

TOTAL SUCTION HEAD (Hs): The suction reservoir pressure head plus the static Suction head plus the velocity head at the pump Suction flange (hvs) minus the friction head in the suction line (hfs). HS=hps+hs+hvs-hfsThe total suction head is the reading of the gauge on the suction flange, converted to feet of liquid.

TOTAL DISCHARGE HEAD (Hd): The discharge reservoir pressure head (hpd) plus static discharge head (hd) plus the velocity head at the pump discharge flange (hvd) plus the total friction head in the discharge line (hfd). The total discharge head the reading of a gauge at the discharge flange, converted to feet of liquid Hd=hpd+hd+hvd+hfdTotal Differential Head (HT): It is the total discharge head minus the total suction head or HT = HD+ HS (WITH A SUCTION LIFT) HT = HD HS (WITH A SUCTION HEAD) 1.11.3 NET POSTIVE SUCTION HEAD(NPSH) Thus the Net Positive Suction head (NPSH) is the total head at the suction flange of the pump less the vapor pressure converted to fluid column hight of the liquid.

1.12 PULLEY

A pulley is a wheel on an axle that is designed to support movement of cable or belt along its circumference. Pulleys are used in a variety of ways to lift loads, apply forces, and to transmit power. A pulley is also called a sheave or drums and may have a groove between two flanges around its circumference. The drive element of a pulley system can be a rope, cable, belt, or chain that runs over the pulley inside the groove. Hero of Alexandria identified the pulley as one of six simple machines used to lift weights. Pulleys are assembled to form a block and tackle in order to provide mechanical advantage to apply large forces. Pulleys are also assembled as part of belt and chain drives in order to transmit power from one rotating shaft to another.

1.12.1 BLOCK AND TACKLE A set of pulleys assembled so they rotate independently on the same axle form a block. Two blocks with a rope attached to one of the blocks and threaded through the two sets of pulleys form a block and tackle. A block and tackle is assembled so one block is attached to fixed mounting point and the other is attached to the moving load. The mechanical advantage of the block and tackle is equal to the number of parts of the rope that support the moving block.

1.12.2 ROPE AND PULLEY SYSTEM A rope and pulley system, that is a block and tackle, is characterized by the use of a single continuous rope to transmit a tension force around one or more pulleys to lift or move a load the rope may be a light line or a strong cable. This system is included in the list of simple machines identified by Renaissance scientists. If the rope and pulley system does not dissipate or store energy then its mechanical advantage is the number of parts of the rope that act on the load. This can be shown as follows. Consider the set of pulleys that form the moving block and the parts of the rope that support this block. If there is p of these parts of the rope supporting the load W, then a force balance on the moving block shows that the tension in each of the parts of the rope must be W/p. This means the input force on the rope is T=W/p. Thus, the block and tackle reduces the input force by the factor p.

Figure-5 Rope and Pulley systemHOW IT WORKS Simplest theory of operation for a pulley system assumes that the pulleys and lines are weightless, and that there is no energy loss due to friction. It is also assumed that the lines do not stretch.In equilibrium, the forces on the moving block must sum to zero. In addition the tension in the rope must be the same for each of its parts. This means that the Iwo parts of the rope supporting the moving block must each support one-half the load.

FIXED: A fixed pulley has an axle mounted in bearings attached to a supporting structure. A fixed pulley changes the direction of the force on a rope or belt that moves along its circumference. Mechanical advantage is gained by combining a fixed pulley with a movable pulley or another fixed pulley of a different diameter.

MOVABLE: A movable pulley has an axle in a movable block. A single movable pulley is supported by two parts of the same rope and has a mechanical advantage of two.

COMPOUND: A combination of fixed and movable pulleys forms a block and tackle. A block and tackle can have several pulleys mounted on the fixed and moving axles, further increasing the mechanical advantage. The luff tackle adds a fixed pulley rove to disadvantage. The tension in the rope remains W/3 yielding an advantage of three. The mechanical advantage of the gun tackle can be increased by interchanging the fixed and moving blocks so the rope is attached to the moving block and the rope is pulled in the direction of the lifted load. In this case the block and tackle is said to be rove to advantage now three rope parts support the load V which means the tension in the rope is W3. Thus the mechanical advantage is three. By adding a pulley to the fixed block of a gun tackle the direction of the pulling force is reversed though the mechanical advantage remains the same, diagram. This is an example of the Luff tackle

1.12.3 BELT AND PULLEY SYSTEM Belt and pulley system is characterized by two or more pulleys in common to a belt. This allows for mechanical power, torque, and speed to be transmitted across axles. If the pulleys are of differing diameters, a mechanical advantage is realized. A belt drive is analogous to that of a chain drive, however a belt sheave may be smooth (devoid of discrete interlocking members as would be found on a chain sprocket. spur gear, or timing bolt) so that the mechanical advantage is approximately given by the ratio of the pitch diameter of the sheaves only, not fixed exactly by the ratio of teeth as with gears and sprockets.In the case of a drum-style pulley, without a groove or flanges, the pulley often is slightly convex to keep the flat belt centered. It is sometimes referred to as a crowned pulley. Though once widely used in factory line shafts, this type of pulley is still found driving the rotating brush in upright vacuum cleaners. Agricultural tractors built up to the early 1950s generally had a belt pulley. It had limited use as the tractor and equipment being powered needed to be stationary, it has thus been replaced by other mechanisms, such as power take-off and hydraulics. Figure-6 Belt and Pulley System

HOW IT WORKSThe simplest theory of operation for a pulley system assumes that the pulleys and lines are weight less, and that there is no energy loss due to friction . It is also assume that the lines do not stretch.In equilibrium, the forces on the moving block must sum to zero. In addition the tension in the rope must be same for each of its part. This means that the two parts of the rope supporting the moving block must each support one- half the load.

THESE ARE DIFFERENT TYPE OF PULLEY SYSTEMFIXED TYPEA fixed pulley has an axel mounted in bearing attached to a support in structure .a fixed pulley change the direction of the force on a rope or belt that moves along its circumference. Mechanical advantage is gained by combing a fixed pulley whit a movable pulley or another fixed pulley of a different diameter.

MOVABLE TYPEA movable pulley has an axel in a movable block single movable pulley supported by two parts of the same rope and has mechanical advantage of two.COMPOUND TYPEA combination of fixed an moveable pulleys forms a block and tackle .a block and tackle can have several pulleys mounted in fixed and moving axles, further increases in mechanical advantage.

1.13 DESIGN OF COMPONENT 4.5.1 SELECTION OF BELT DRIVE Following are the various important factors upon which the selection pf a belt drive depends: . I. Speed of the driving &driven shaft. II. Speed reduction ratio Ill. Power to be transmitted IV. Central distance between the shafts V. Positive drive requirement VI. Shaft layout VII. Space available VIIL Service condition

1.13.1 TYPES OF BELTSFLAT BELTS Flat belts were widely used in the 19th and early 20th centuries in line shafting to transmit power in factories. They were also used in countless farming, mining, and logging applications, such as bucksaws, sawmills, threshers, silo blowers, conveyors for filling corn cribs or haylofts, balers, water pumps (for wells, mines, or swampy farm fields), and electrical generators. Flat belts are still used today, although not nearly as much as in the line shaft era. The flat belt is a simple system of power transmission that was well suited for its day. It can deliver high power at high speeds (500 hp at 10,000 ft/mm).In cases of wide belts and large Pulleys. But these drives arc bulky, requiring high tension leading to high loads, and are poorly Suited to close-centers applications, so vie belts have mainly replaced flat-belts for short-distance Power transmission; and longer-distance power transmission is typically no longer done with belts at all. For example, factory machines now lend to have individual electric motors. Because flat bells lend to climb towards the higher side of the pulley, pulleys were made with a Slightly convex or crowned surface(rather than flat) to allow the belt to self-center as it runs. Flat belts also tend to slip on the pulley face when heavy loads are applied, and many proprietary belt dressings were available that could be applied to the belts to increase friction, and so power transmission. Flat belts were traditionally made of leather or fabric. Today some are made of rubber or polymers. Grip of leather belts is often better if they are assembled with the hair side (outer side) of the leather against the pulley, although some belts arc instead given a half-twist before joining the ends (forming a Mobys strip), so that wear can be evenly distributed on both sides of the belt. Belts ends are joined by lacing the ends together with leather thronging, steel comb fasteners, or glued splices (with thronging being the oldest of the methods). Flat belts were traditionally jointed, and still usually are, but ey can also be made with endless construction.

ROUND BELTS Round belts are a circular cross section belt designed to run in a pulley with a 60 degree V- groove. Round grooves arc only suitable for idler pulleys that guide the belt, or when (soil) 0- ring type belts are used. The V-groove transmits torque through a wedging a1ion, thus increasing friction. Nevertheless, round belts arc for use in relatively low torque situations only and may be purchased in various lengths or cut to length and joined, either by a staple, a metallic connector (in the case of hollow plastic), gluing or welding (in the case of polyurethane). Early machines utilized a leather heft, joined either by a metal staple or glued, to great effect.

VEE BELTSWe belts (also known as V-belt or wedge rope) solved the slippage and alignment problem. It is now the basic belt for power transmission. They provide the best combination of traction, speed of movement, load of the bearings, and long service life. They are generally endless, and their general cross-section shape is trapezoidal (hence the name V). The V shape of the heft tracks in a mating groove in the pulley (or sheave), with the result that the belt cannot slip off. The belt also tends to wedge into the groove as the load increases - the greater the load. The greater the Wedging actionimproving torque transmission and making the V-belt an effective solution. Needing less width and tension than flat belts. V-belts trump flat belts with their small center distances and high reduction ratios. The preferred center distance is larger than the largest pulley diameter but less than three tine the sum of both pulleys. Optimal Speed range is 1000 -7000ft/min. V-belts need larger pulleys for their larger thickness than flat Belt. For high-power requirements, two or more V belts can be joined side-by-side in an arrangement called a multi-V, running on matching multi-groove sheaves. This is known as a multiple-V-belt drive (or sometimes a classical V-belt drive). V-belts may be homogeneously rubber or polymer throughout or there may be fibers embedded in the rubber or polymer for strength and reinforcement. The fibers may be of textile materials such as cotton or polyester or, for greatest strength, of steel or armed (such as Twaron or Kevlar). When an endless belt does not fit the need, jointed and link V-belts may be employed. However they are weaker and only usable at speeds up to 4000 ft/mm. A link v-belt is a number of rubberized fabric links held together by metal fasteners. They arc length adjustable by disassembling and removing links when needed.

1.13.2 BELT MATERIAL LEATHER Oak tanned or chrome tanned.

RUBBER Canvas or cotton duck impregnated with rubber. For greater tensile strength, the rubber belts are reinforced with steel cords or nylon cords.

PLASTICS Thin plastic sheets with rubber layers.

FABRIC Canvas or woven cotton ducks the belt thickness can be built up with a number of layers. The number of layers is known as ply. The belt material is chosen depending of the use and application. Leather oak tanned belts and rubber belts are the most commonly used hut the plastic belts have a very good strength almost twice the strength of leather belt. Fabric belts arc used for temporary or short period operations.

1.13.3 FLAT BELT DRIVES Flat belts drives can be used for large amount of power transmission and there is no upper limit distance between the Iwo pulleys Belt conveyer system is one such example. These drives are efficient at high speeds and they offer quite running. A typical flat belt drive with idler pulley is. Idler pulleys are used to guide a flat belt in various manners, but do not contribute to power transmission. The flat belts are marketed m the form of coils. Flat belts are available for a wide range of width, thickness, weight and material. Depending upon the requirement one has to cut the required belt length from the coil and join the ends together. The fixing of the joint must be done properly because the belt normally gets snapped from the improper joints. The best way is to use a cemented belt from the factory itself or with care one can join these belts with various types of clips that are available in the market.

1.13.4 TYPES OF BELT DRIVEThe power from one pulley to another may be transmitted by any of the following types of belt dries

OPEN BELT DRIVE: The open belt drive, as shown in figure, is used with shafts arranged parallel and rotating in the same direction. In this case, the driver A pulls the belt from one side and delivers it to other side. Thus the tension in the lower side belt will be more than that in the upper side belt. The lower side belt is known as slack side, as shown in figure.

Figure-7 Open belt drive

CROSSED OR TWIST BELT DRIVE: The crossed or twist belt drive, as shown in figure, is used with shafts arranged parallel and rotating in the opposite directions. In this case the driver pulls the belt from one side and delivers it to other side. Thus the tension in the belt RQ will be more than that in the belt LM is known as slack side, as shown in figure.

Figure-8 Crossed belt drive

QUARTER TURN BELT DRIVE The quarter turns belt drive (also known as right angle belt drive) as shown in figure. is used with Shafts arranged at right angles and rotating in one definite direction. In order to prevent the belt from leaving the pulley, the width of the face of the pulley should he greater or equal to.

BELT DRIVE WITH IDLER PULLEYS: A belt drive with an idler pulley( also known as jockey pulley drive) as shown in figure, is used with shafts arranged parallel and when open belt drive cannot be used to small angle of contact on the smaller pulley. This type of drive is provided to obtain high velocity ratio and when the required belt tension cannot be obtained by other means, when it is desired to transmit motion from one shaft to several shafts, all arranged in parallel, a belt drive with many idler pulleys, as shown in figure, may be employed

COMPOUND BELT DRIVEA compound belt drive as shown in figure is used when power is transmitted from one shaft to another through a number of pulleys. Figure-9 Compound belt drive

STEPPED OR CONE PULLEY DRIVE A stepped or cone pulley drive, as shown in figure, is used for changing the speed of the driven shaft while the main or driving shaft runs at constant speed. This is accomplished by shifting the belt from one part of the steps to the other. Figure 10 Stepped pulley drive

1.13.5 ADVANTAGES OF BELT DRIVE

I. They are simple. They are economical. 11. Parallel shafts are not required. III. Overload and jam protection arc provided. IV. Noise and vibration are damped out. Machinery life is prolonged because load fluctuations are cushioned (shock-absorbed). V. They arc lubrication-free. They require only low maintenance. VI. They arc highly efficient (9098%. usually 95%). Some misalignment is tolerable. VII. They are very economical when shafts are separated by large distances

1.13.6 DISADVANTAGES OF BELT DRIVE I. The angular-velocity ratio is not necessarily constant or equal to the ratio of pulley diameters, because of belt slip and stretch.II. Heat buildup occurs. Speed is 1imit9I to usually 7000 feet per minute (35 meters per second). Power transmission is limited to 370 kilowatts (500 horsepower).III. Operating temperatures are usually restricted to 3110 185F (35 to 85C). IV. Some adjustment of center distance or use of an idler pulley is endless belts. Necessary for wear and stretch compensation. V. A means of disassembly must he provided to install

CHAPTER-2

HISTORY

Ever since the arrival of fossil fuels and electricity, human powered tools and machines have been viewed as an obsolete technology. This makes it easy to forget that there has been a great deal of progress in their design, largely improving their productivity. The most efficient mechanism to harvest human energy appeared in the late 19th century: pedaling. Stationary pedal powered machines went through a boom at the turn of the 20th century, but the arrival of cheap electricity and fossil fuels abruptly stopped all further development.

2.1 HAND CRANKS, CAPSTANS & TREAD WHEELS Rotary motion has been the fundamental mechanism of most machines throughout human history. There have been several important innovations in applying human power to rotary motion, many of which at appear in Antiquity: the bow (see the article on human powered drilling tools), the hand era - e capstan and the tread wheel (these are described in more detail in the article on human powered cranes). Successively, each of these brought an improved mechanical advantage, being the factor by which the mechanism multiplied the human (or sometimes animal) input force into an higher output force. A hand crank had a mechanical advantage of about 2 to 1, meaning that the mechanism doubled the effort of the user. With a capstan, the mechanical advantage went up to about 6 to 1. A typical tread wheel, which had a diameter of at least 4 meters, had a mechanical advantage of about 14 to 1. This meant that a person walking a tread wheel could exert 7 times more torque (the force to rotate an object about an axis) than a person operating a hand crank. Or. that a person could generate the same amount of torque with 7 limes less effort.

Figure 11, Hand Cranks, Capstans & Tread Wheels

The tread wheel had another advantage over the hand crank: it replaced the use of the arm muscles by the use of the much stronger leg muscles, and it allowed the use of two limbs instead of one. The same effort could thus be sustained over a longer time - or a higher force could be exerted over the same time. To a lesser extent, the same advantage was valid for the capstan, where the legs did a large part of the work.

2.2 TREADLES Another novelty appeared in the middle Ages: the treadle. From the 10th century onwards, the Chinese used wooden treadles to obtain continuous motion for water pumps, textile, and machinery and wood saws. In the western world, treadles were mainly applied to spinning wheels and lathes (machine tools used for working metal and wood). Treadles were inefficient compared to capstans and tread wheels (feet and legs must be accelerated and subsequently decelerated by the muscles) but they were more compact and a viable alternative when power requirements were low. Their main advantage over the hand crank was that they left both hands free to control the machine.

Figure 12, Treadles

2.3 A BOOM OF PEDAL POWERED MACHINESThe cleverest innovation in applying human power to rotary motion only appeared in the 1870s. Some of us still use it as a means of transportation, but it is rarely applied to stationary machines any more: pedal power. Initially, pedals and cranks were connected directly to the front (or sometimes rear) wheel. With the arrival of the safety bicycle shortly afterwards, this direct power transmission was replaced by a chain drive and sprockets - still the basics of most present- day bicycles. Pedal power did not come out of the blue: some of the first bicycles were equipped with treadles, which could be considered the predecessor of the pedal.

Figure 13, A Boom Of Pedal Powered Machines

On their own, pedals and cranks did not offer a better mechanical advantage than the hand crank, let alone the capstan or the tread wheel. What made pedal power so revolutionary was that it offered the possibility to use the stronger leg muscles in a continuous motion while at the same time offering a much more compact mechanism than the capstan or the tread wheel.Moreover, using the appropriate gear ratio (using chains and sprockets of different sizes) a mechanical advantage sim1ar to that of a capstan or a tread wheel could be achieved (multiplying torque at the expense of speed or vice versa). This made pedal power suitable for a much larger variety of applications. From 1876 onwards pedals and cranks were attached to tools like lathes, saws, grinders, shapers, tool sharpeners and to boring, drilling and cutting machines. These machines which became very popular- were intended for small workshops and households without electricity or steam Power. They were made with heavy cast-iron bodies that could be collapsed for shipping. Pedals and cranks did not make treadles and hand cranks obsolete. On the contrary these tools became more sophisticated (made of steel instead of wood, for example, or using gears inspired by bicycles) and became increasingly popular for low or brief power applications.

CHAPTER-3

WORKING PRINCIPLEThe mechanism consists of single centrifugal pump which is fixed with the rear wheel bicycle. The system comprises a bicycle, rim, belt pulley, impeller and inlet and delivery pipes. The back type is replaced by a bare rim which is connected to another pulley of smaller diameter. The supporting shaft of the smaller pulley carries another rim for second stage speed increment. A flywheel is also included in the shaft to increase momentum of the system. The final supporting shaft is connected with an impeller that rotates at high speed and pumps water. The power generated by the process of pedaling the bicycle is used to lift the water and push the water from a pipe into the farm for cultivation useful for pumping water from rivers, ponds, wells and similar water sources. The farmers can use this to pump water for irrigation. This is a cycle based portable centrifugal pump. The water pump is mounted on the carrier over the rear wheel of a bicyclical power is transferred from two pulleys attached at the back of wheel. The pump is placed on a platform placed at the rear carrier of bicycle. The unit comprises 2 inch suction pipe fabricated frame, 1 inch delivery pipe, stand, foot valve. It is used for lifting water for various purposes like development of dry land, as a fire extinguisher, for construction work, used in gymnasium and for irrigation. The bicycle is taken to the water source, parked and peddled on its stand to operate the pump. It is- it is Pollution free No electricity and no fuel are required. Operated by human power Light in weight.

Want to pump water from the sump to the overhead tank on top of the third floor of your house without shelling out extra money for electricity? Here is a machine that does not only pump Water without electricity. Hut also keeps ones body physically fit without spending time in gym.It is common that people in cities like Mangalore and Bangalore struggle to ensure their overhead water tanks are tilled due to power problems. Most of the residents store water in sumps when tanks are not tilled due to low pressure in the water supply of corporations. Again the stored water will have to be pumped everyday using electric motors. Another advantage of the machine is that it is an exerciser too as it has been designed like a pedal pusher exerciser. 10 minutes of pedaling will not only increase the carbohydrate burning rate, but also will pump water from the sump to the overhead tank on the third floor.

Our project could prove helpful for rural areas which are facing load shedding problems. It can be used mainly for irrigation and water drawing water from wells and other water bodies. This is a centrifugal water pump which is run by rotating the paddle of a cycle. The system comprises a bicycle, rim, impeller, pulley, inlet, and delivery pipes. A wheel is connected to another pulley with a smaller diameter the final supporting shaft is connected with an impeller through this process of paddling is used to lift water from a pipe into the form for cultivation. This innovation is useful for pumping water from river, ponds, wells and similar water sources thus enabling poor farmers for pumping water for irrigation and cultivation. We drive a bicycle by using a paddling the wheel of the bicycle rotates a particular rpm. And this wheel rotates the impeller of the centrifugal pump by sliding action between wheel and pulley but the rpm of the wheel is very low so we cannot get required and power effort on the padding is low so we can use the pulley which is mounted on the shaft of the pump and creates the high rpm by using less power. In this operation liquid and their moment and transfer from place to place, plays a large part in the process. Liquid can only flow under its own power from higher elevation to lower elevation or from a higher presser system to lower presser system.The flow of liquid is also affected by friction, pipe size, liquid viscosity and the bends and fitting in the piping. To overcome flow problems and to move liquids from place to place, against a higher pressure or to a higher elevation, energy must be added to the liquid. To add the required energy to liquids, we used pumps. A pump therefore is defined as a machine used to add energy to a liquid. Pumps come in many types and sizes. The type depends upon the function the pump is to perform and the size (and speed) depends upon the amount (volume) of liquid to be move in a given time

3.1 WORKING MECHANISM OF ROTARY PUMPA centrifugal pump is one of the simplest pieces of equipment in any process plant its purpose is to convert energy of a prime mover (a electric motor or turbine) first into velocity or kinetic energy and then into pressure energy of a fluid that is being pumped. The energy changes occur by virtue of two main parts of the pump, the impeller and the volute or diffuser.The impeller is the rotating part that converts driver energy into the kinetic energy. The volute or diffuser is the stationary part that converts the kinetic energy into pressure energy. The process liquid enters the suction nozzle and then into eye (centre) of a revolving device known as an impeller. When the impeller rotates, it spins the liquid sitting in the cavities between the vanes outward and provides centrifugal acceleration. As liquid leaves the eye of the impeller a low pressure area is created causing more liquid to flow toward the inlet. Because the impeller blades are curves, the fluid is pushed in a tangential and radial direction by the centrifugal force.

CHAPTER-4

PROJECT WORK4.1 SOURCE OF PEDAL POWER Pedal power is the source of getting energy from human beings. It can be described as the transfer of the energy generated through the moment of the human feet and hands in some cases. Humans used the pedal power to impel bicycles for centuries. In the primeval time all the machinery were manual and required the physical energy to run them. This use of pedal power proved to be really helpful to perform even hard labor tasks. Pedal power was the base of the industry for many years. The use of pedal power is also strengths the muscles. The use of pedal developed over a time. However now a days, it has become a useful and economical way of generating energy. The energy generated in this process is also used to produce electricity. Worldwide especially in the underdeveloped countries use of bicycle pedals is still the key to run the industries. This practice is common in these countries in order to save electricity and labor costs. Still in the under developed countries of the world, the readymade stitching industry is heavily based on pedal sawing machines. Pedal power has been utilized in a really efficient manner, and really unique tools have been introduced.4.2 APPLICATION OF PEDAL POWER-Some of the greatest inventions of the centuries using pedal power are pedal power laptops, pedal power snowplow, pedal power wheel chairs, and pedal power dynamo. These machines have not helped the human race to perform physical activities but over the years it has proved to be an effective source of energy generation. Another amazing creation to utilize pedal power is pedal power generators. Pedal power generators produce electric current in few minutes and allow you to change the batteries of all kinds. Various forms of batteries which can be charged include laptop, mobile, cameras and i-pod batteries. Human kind has realized that pedal power is a safe and environment friendly way to generate energy. Moreover the use of pedals has many health benefits as well. Doctors all over the world emphasizes on riding bicycles on early morning for improving overall health and losing weight. Australian government has started a tax free bicycle scheme offered to office workers in order to hoard fuel. A recent launch of wind stream Power Company is pedal power generator. The company declares it best to be used in remotes areas facing energy crises. These pedal power generators are designed to crank either by hands or by using feet.

4.3 WORKING OF PEDAL POWER-The idea of pedal power generation emerged from the wind turbines. Recent trend towards the use of bicycle again has gained great popularity. The report shows that in Northern America the use of bicycle has increased in recent years. The credit goes to the effort of the people who provided awareness to the masses about its benefits. Recent trends have also forced the people to start thinking about the ways to generate electricity using pedal power. Some people have implanted pedal power windmills in their farm houses to convert this kinetic energy into current. In many parts of the world this pedal power is the bread and butter for many .in the under developed countries like India and Bangladesh masses ride bicycle rickshaw to carry commuters .This practice has been in use from centuries and this has become their culture now. In india the pedal power industry still accounts for 18 percent of the total industry. India has the largest bicycle industry after china. Along with energy benefits that pedal power offers, bicycle has proved to be the great ride. Riding bicycle can be joyous experience when you tear across the wind along the road. It can be a great fun activity and an ideal time pass. Pedal power can proved to be safe and economical energy generation plan.

4.4 COMPONETS USED CENTRIFUGAL PUMP BICYCLE PULLEY

4.4.1 CENTRIFUGAL PUMP Centrifugal pumps are a sub-class of dynamic ax symmetric work-absorbing turbo machinery. Centrifugal pumps are used to transport fluids by the conversion of rotational kinetic energy to the hydrodynamic energy of the fluid flow. The rotational energy typically comes from an engine or electric motor, but in this case pedal power is used for the purpose. In the typical case, the fluid enters the pump impeller along or near o the rotating axis and is accelerated by the impeller, flowing radials outward into a diffuser or volute chamber (casing), from where ii exits. REASONS FOR SELECTING CENTRIFUGAL PUMP OVER RECIPROCATING PUMP SIMPLICITY The centrifugal pump Consists of housing with an inlet and outlet and an impeller that rotates inside the housing to move liquid. The reciprocating pump is more complex in design and consists of housing with a piston-connecting rod system inside, similar to your cars engine. A crankshaft within the pump rotates, causing the connected piston to travel back and forth in a linear motion. With the aid of two check valves, the piston first draws liquid in and then reverses direction, forcing the liquid back out through a separate port.

Figure 14, Centrifugal PumpFLOOR SPACE AND CAPACITY Centrifugal pumps require less floor space than reciprocating pumps of equal capacity because of the simpler design. Also, the capacity of the centrifugal pump can be increased more easily by enlarging the inlet and outlet diameters and increasing the impeller speed. Flow The smooth rotating motion of the impeller in the centrifugal pump allows for a more even discharge of fluids than the pulsating motion of the piston in the reciprocating pump. Pulsating flow of liquids may require special design considerations for piping systems.

MAINTENANCEMaintenance can be performed on both types of pumps relatively easily and quickly. However, the centrifugal pump tends to have a Longer performance time before maintenance and/or repairs are required because it has fewer moving parts. In addition, repair time can be shorter and less costly

4.4.2 BICYCLE Bicycles were introduced in the 19th century in Europe and now number more than a billion worldwide, twice as many as automobiles. They are the principal means of transportation in regions. They also provide a popular form of recreation, and have been adapted for such uses as childrens toys, general fitness, military and police applications, courier services and bicycle racing. It is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclists or bicyclist. We have used a bicycle for providing motion to the centrifugal pump and thus we can water by peddling as it we are cycling amendments were required to be done on the bicycle to implant it in our project These amendments are as follows: 1. We have removed the tyre and tube front the rear wheel. 2. The cycle was clamped onto the frame. 3. A rubber and belt is used to transfer the rot motion to the shaft with which centrifugal pump is mounted. 4. The rear rim serves the purpose of o pulley and the other pulley is attached to the driven shaft 4.4.3 PULLEY

Pulley is made of Mild Steel. Pulley shaft is supported on four vertical bolts and nut assembly with the help of pedestal bearings. Sewing machine rope is used to rotate pulley shaft. As rim diameter is 420 mm & pulley diameter is mm so we can easily achieve the speed of pulley shall 18 times greater than speed of rim. As bicycle rim rotates, pulley starts rotating due to friction effect & hence shaft of centrifugal pump also rotates & we get output from centrifugal Pump

4.6 WORKING OF THE MODEL This project is a step in the area of construction of energy. In the absence of power, I migration is adversely affected. In this pedal operated pump, we are required to pedal the bicycle. The sprocket of the bicycle conflicts the pedal to the rear wheel by a chain drive. The power is thus transmitted to the rear wheel. Now the rear wheel drives a pulley by a belt drive which is mounted on the shaft of the centrifugal pump. The diameter of the pulley is very small in comparison to the rear rim so that power obtained is substitution. The centrifugal pump pumps the Waller from the sump t the derived location. The entire assembly of the bicycle, centrifugal pump and pulley is mounted on a frame. Base frame of the project consist of L shaped strips of mild steel. . It is completely rectangular welded structure which is easily fabricated in any workshop. This frame takes load of whole assembly with bicycle rim, paddle & seating arrangement, shaft and pulley assembly, which is rest on ground. On this rectangular structure pulley & shaft assembly rotates with the help of rope pulley. Supporting M.S. circular pipes arc welded to base frame for mounting of bicycle rim.

Figure 15, Working Of The Model

1. 4.7 ADVANTAGES OF PEDAL OPERATED PUMP 1. It is renewable as well as sustainable. As it is needed till the human existence on this planet and the ultimate source is the human himself. 2. It is cost-effective so everyone can access to its advantages. There is only need to set pedal with crank system attached to the drive. 3. It is pure energy zero percent carbon emission so clean and healthy surroundings. 4. It keeps the body system well and increases the efficiency level 11usd to a certain extent. Excess use of anything is bad for health: 5. It does not harm the socio-political benefits as it is the personal property of every individual. 6. Pedal power energy concept is not newer just renewed in the modem times because once again there is need to shift towards is to protect the environment. It does not mean that the advancement in technology will not proceed. It provides a secure environment to do positive work. It will increase the efficiency level of man power.

4.8 DISADVANTAGES OF PEDAL OPERATED PUMP 1. The discharge is not comparable to that obtained by power operated pump. 2. It is suitable only for rural areas where small water bodies like pond and well are available from which we can draw water.3. Continuous effort is required for obtaining a continuous supply. 4. It is not at all fruitful for commercial purposes5. Prior to pumping priming is required to be done for centrifugal rump 6. Cavitations of centrifugal pump.

4.9 THE FUTURE OF PEDAL POWERED MACHINESIf we boost the research on pedal powered technology- trying to make up for seven decades of lost opportunities and steer it in the right direction, pedals and cranks could make an important contribution to running a post-carbon society that maintains many of the comforts of a modern life. The possibilities of pedal power therefore largely exceed the use of the bicycle.Peddlers could power agriculture, factories, construction, mining and even other means of transportation than bicycles: aerial ropeways, cable trains and trolley boats. Pedal powered electricity plants could be a valuable backup solution to intermittent renewable energy sources, replacing coal, gas and nuclear as a base load power for when the sun and wind let us down. Human power is available 24 hours per day, is not affected by changes in the weather, is portable and can easily be stored for later use. Contrary to wind and biomass , it is and energy source that will never be depleted, since its potential keeps pace with population growth. Pedal power would also aid unemployment, leave us with a fit and healthy workforce, and produce a great deal of nice-looking bottoms

4.10 COST OF THE PROJECT

S.NO.Component Description Cost in INR

1. Bicycle 900

2. Iron Strips for frame300

3. Pump and Pulley assembly700

4. Belt50

5. Other Expenditure 300

Total Expenditure 2250

CONCLUSIONS

The problem of energy crises is very severe in India and many rural areas are using powered water pump. By use of this project we can save electricity and get a particular water head and thus we can supply the water for irrigation. We have operated a water pump by using bicycle mechanism in the project and we can fill the water tank or housing. When we drive a bicycle the wheel of the bicycle rotates so we can treat it as a pulley and a pulley is mounted on the shaft of impeller of the pump. The impeller rotates due to rotation of wheel with rotation of pulley. The efficiency of the pedal pump was found good and an operator is capable to work with it for a long time (more than 2 hours) continuously without being tired. The pump is capable to tap water from a shallow depth (< 2 m) effectively and is, therefore, expected to be suitable to supply irrigation water in small fragmented land holdings as well as in small irrigation project areas and construction cost of the pedal pump is also comparatively low. Overall it was an interesting task for me and I have enjoyed the entire period in was engaged in the making of this project. I hope to cherish the memory of the task for long time. This project also helped me to clarify my doubts which I came through while studying these concepts in theoretical papers.

REFERENCE

1. Innovation System Design and Engineering 2. Machine Design (S.I. Units) by R.S. Khurmi & J.K Gupta3. Pump for Low List Irrigation Publisher JARD4. Centrifugal Pump Purified water Supply Device Published.5. Www. Wikipeaida.com6. ADEMOLO SUMUEL AKINWANMI, STEPHAN

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