CONTENTS CHAPTER NO TITLE SYNOPSIS LIST OF FIGURES NOMENCLATURE

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3 CONTENTS CHAPTER NO TITLE SYNOPSIS LIST OF FIGURES NOMENCLATURE 1 Introduction 2 Literature review 3 Description of equipments 3.1 Solar panel components 4 Design and drawing 4.1 components and Specification 4.2 Design calculation 5 fabrication 6 Working principle 7 Merits and demerits 8 applications 9 List of materials 10 Cost Estimation 11 Conclusion Bibliography photography

4 NOMENCLATURE

5 NOMENCLATURE A =Area of solar panel(m 2 ) D=Diameter of motor shaft (m) F =Force exerted on the pump (N) p=pressure (N/m 2 ) P=power (W) I =current (A) V=voltage (volts) N =speed ( rpm)

6 SYNOSPSIS

7 SYNOPSIS: This project is the process of removing heat from substance under controlled conditions. In a reversed system which pumps heat from a cold body and delivers it to a hot body. The system which works on a extraction of heat from a cold body and deliver it to a hot body is called cooling tower.

8 INTRODUCTION

9 INTRODUCTION Cooling towers are a very important part of many chemical plants. The primary task of a cooling tower is to reject heat into the atmosphere. They represent a relatively inexpensive and dependable means of removing low-grade heat from cooling water. The make-up water source is used to replenish water lost to evaporation. Hot water from heat exchangers is sent to the cooling tower. The water exits the cooling tower and is sent back to the exchangers or to other units for further cooling. Typical closed loop cooling tower system.

10 LITERATURE SURVEY

11 LITERATURE SURVEY COOLING TOWER TYPES Cooling towers fall into two main categories: Natural draft and Mechanical draft. Natural draft towers use very large concrete chimneys to introduce air through the media. Due to the large size of these towers, they are generally used for water flow rates above 45,000 m3/hr. These types of towers are used only by utility power stations. Mechanical draft towers utilize large fans to force or suck air through circulated water. The water falls downward over till surfaces, which help increase the contact time between the water and the air - this helps maximise heat transfer between the two. Cooling rates of Mechanical draft towers depend upon their fan diameter and speed of operation. Since, the mechanical draft cooling towers are much more widely used, MECHANICAL DRAFT TOWERS Mechanical draft towers are available in the following airflow arrangements: I. Counter flows induced draft. 2. Counter flow forced draft. 3. Cross flow induced draft. In the counter flow induced draft design, hot water enters at the top, while the air is introduced at the bottom and exits at the top. Both forced and induced draft fans are used. In cross flow induced draft towers, the water enters at the top and passes over the fill. The air, however, is introduced at the side either on one side (single-flow tower) or opposite sides (double-flow tower). An induced draft fan draws

12 the air across the wetted fill and expels it through the top of the structure. The Figure 7.2 illustrates various cooling tower types. Mechanical draft towers arc available in a large range of capacities. Normal capacities range from approximately 10 tons, 2.5 m3/hr flow to several thousand tons and m /hr. Towers can be either factory built or field erected for example concrete towers arc only field erected. Many towers arc constructed so that they can be grouped together to achieve the desired capacity. Thus, many cooling towers are assemblies of two or more individual cooling towers or cells. The number of cells they have, e.g., a eightcell tower, often refers to such towers. Multiple-cell towers can be lineal, square, or round depending upon the shape of the individual cells and whether the air inlets are located on the sides or bottoms of the cells. COMPONENTS OF COOLING TOWER The basic components of an evaporative tower arc: Frame and casing, fill, cold water basin, drift eliminators, air inlet, louvers, nozzles and fans. FRAME AND CASING: Most towers have structural frames that support the exterior enclosures (casings), motors, fans, and other components. With some smaller designs, such as some glass fiber units, the casing may essentially he the frame. Fill: Most towers employ fills (made of plastic or wood) to facilitate heat transfer by maximising water and air contact. Fill can either be splash or film type. With splash till, waterfalls over successive layers of horizontal splash bars, continuously breaking into smaller droplets, while also wetting the till surface. Plastic splash till promotes better heat transfer than the wood splash fill. Film fill consists of thin, closely spaced plastic surfaces over which the water spreads, forming a thin film in contact with the air.

13 COLD WATER BASIN: The cold water basin, located at or near the bottom of the tower, receives the cooled water that flows down through the tower and fill. The basin usually has a sump or low point for the cold water discharge connection. En many tower designs, the cold water basin is beneath the entire till. In some forced draft counter flow design, however, the water at the bottom of the till is channelled to a perimeter trough that functions as the cold water basin. Propeller fans are mounted beneath the fill to blow the air up through the tower. With this design, the tower is mounted on legs, providing easy access to the fans and their motors. DRIFT ELIMINATORS: These capture water droplets entrapped in the air stream that otherwise would be lost to the atmosphere. Air inlet: This is the point of entry for the air entering a tower. The inlet may take up an entire side of a tower cross flow design or be located low on the side or the bottom of counter flow designs. Louvers: Generally, cross-flow towers have inlet louvers. The purpose of louvers is to equalize air flow into the fill and retain the water within the tower. Many counter flow tower designs do not require louvers. NOZZLES: These provide the water sprays to wet the fill. Uniform water distribution at the top of the fill is essential to achieve proper wetting of the entire fill surface. Nozzles can either be fixed in place and have either round or square spray patterns or can be tart of a rotating assembly as found in some circular cross-section towers.

14 FANS: Both axial (propeller type) and centrifugal fans arc used in towers. Generally, propeller fins are used in induced draft towers and both propeller and centrifugal fans arc found in forced draft towers. Depending upon their size. piopeller fans can either be fixed or variable pitch. A fan having non-automatic adjustable pitch blades permits the same fan to be used over a wide range of kw with the fan adjusted to deliver the desired air flow at the lowest power consumption. Automatic variable pitch blades can vary air flow in response to changing load conditions. Tower Materials In the early days of cooling tower manufacture, towers were constructed primarily of wood. Wooden components included the frame, casing, louvers, fill, and often the cold water basin. If the basin was not of wood, it likely was of concrete. Today, tower manufacturers fabricate towers and tower components from a variety of materials. Often several materials are used to enhance corrosion resistance, reduce maintenance, and promote reliability and long service life. Galvanized steel, various grades of stainless steel, glass fiber, and concrete are widely used in tower construction as well as aluminum and various types of plastics for some components. Wood towers are still available, but they have glass fiber rather than wood panels (casing) over the wood framework. The inlet air louvers may be glass fiber, the fill may be plastic, and the cold water basin may be steel. Larger towers sometimes are made of concrete. Many towers casings and basins are constructed of galvanized steel or, where a corrosive atmosphere is a problem, stainless steel. Sometimes a galvanized tower has a stainlcss stccl basin. Glass fiber is also widely used for cooling tower casings and basins, giving long life and protection from the harmful effects of many chemicals.

15 Heal Load The heat load imposed on a cooling tower is determined by the process being served. The degree of cooling required is controlled by the desired operating temperature level of the process. In most cases, a low operating temperature is desirable to increase process efficiency or to improve the quality or quantity of the product. In some applications (e.g. internal combustion engines), however, high operating temperatures arc desirable. The size and cost of the cooling tower is proportional to the heat load. If heat load calculations are low undersized equipment will be purchased. If the calculated load is high, oversize and more costly, equipment will result. Process heat loads may vary considerably depending upon the process involved, Determination of accurate process heat loads can become very complex but proper consideration can produce satisfactory results. On the other hand, air conditioning and refrigeration heat loads can be determined with greater accuracy. Information is available for the heat rejection requirements of various types of power equipment. FACTORS WET BULB TEMPERATURE Wet bulb temperature is an important factor in perfonnancc of evaporative water cooling equipment. It is a controlling factor from the aspect of minimum cold water temperature to which water can be cooled by the evaporative method. Thus, the wet bulb temperature of the air entering the cooling tower determines operating temperature levels throughout the plant, process, or system. T

16 Theoretically, a cooling tower will cool water to the entering wet bulb temperature, when operating without a heat load. However, a thermal potential is required to reject heat, so it is not possible to cool water to the entering air wet bulb temperature, when a heat load is applied. The approach obtained is a function of thermal conditions and tower capability. Initial selection of towers with respect to design wet bulb temperature must be made on the basis of conditions existing at the tower site. The temperature selected is generally close to the average maximum wet bulb for the sununer months. An important aspect of wet bulb selection is, whether it is specified as ambient or inlet. The ambient wet bulb is the temperature, which exists generally in the cooling tower area, whereas inlet wet bulb is the wet bulb temperature of the air entering the tower. The later can be. and often is, affected by discharge vapours being re circulated into the tower. Recirculation raises the effective wet bulb temperature of the air entering the tower with corresponding increase in the cold water temperature. Since there is no initial knowledge or control over the recirculation factor, the ambient wet bulb should be specified. The cooling tower supplier is required to furnish a tower of sufficient capability to absorb the effects of the increased wet bulb temperature peculiar to his own equipment. It is very important to have the cold water temperature low enough to exchange heat or to condense vapours at the optimum temperature level. By evaluating the cost and size of heat exchangers versus the cost anti size of the cooling tower, the quantity and temperature of the cooling tower water can be selected to get the maximum economy for the particular process.

17 EFFICIENT SYSTEM OPERATION COOLING WATER TREATMENT Cooling water treatment is mandatory for any cooling tower whether with splash fill or with film type fill for controlling suspended solids, algac growth, etc. With increasing costs of water, efforts to increase Cycles of Concentration (COC), by Cooling Water Treatment would help to reduce make up water requirements significantly. In large industries, power plants, COC improvement is often considered as a key area for water conservation. COOLING TOWER FANS The purpose of a cooling tower fan is to move a specified quantity of air through the system, overcoming the system resistance which is defined as the pressure loss. The product of air flow and the pressure loss is air power dcvclopcdlwork done by the fan; this may be also termed as fan output and input kw depends on fan efficiency. The fin efficiency in turn is greatly dependent Ofl the profile of the blade. An aerodynamic profile with optimum twist, taper and higher coefficient of lift to coefficient of drop ratio can provide the fan total efficiency as high as %. However, this efficiency is drastically affected by the factors such as tip clearance, obstacles to airflow and inlet shape, etc. As the metallic fans are manufactured by adopting either extrusion or casting process it is always difficult to generate the ideal aerodynamic profiles. The FRP blades are normally hand moulded which facilitates the generation of optimum aerodynamic profile to meet specific duty condition more efficiently. Cases reported

18 where replacement of metallic or Glass fibre reinforced plastic fan blades have been replaced by efficient hollow FRP blades, with resultant fan energy savings of the order of 20-30% and with simple pay back period of 6 to 7 months. Also, due to lightweight, FRP fans need low starting torque resulting in use of lower HP motors. The lightweight of the fans also increases the life of the gear box, motor and bearing is and allows for easy handling and maintenance.

19 DESCRIPTION OF EQUIPMENT

20 DESCRIPTION OF EQUIPMENT COMPONENTS Fan Dc pump Sump tank FAN A stand alone fan is typically powered with an electric motor. Fans are often attached directly to the motor's output, with no need for gears or belts. Smaller fans are often powered by shaded pole AC motors or brushed or brushless DC motors. In our case it is powered by dc motor having three blades. DC CENTRIFUGAL PUMP: Centrifugal pump is a rotodynamic pump that uses a rotating impeller to increase the velocity of a fluid. Centrifugal pumps are commonly used to move liquids through a piping system. The fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flowing radially outward into a diffuser or volute chamber, from where it exits into the downstream piping system. Centrifugal pumps are used for large discharge through smaller heads The pump is made of molded plastic. The flow rate of the pump is 1 liter / min and it can deliver the water up to a head of 3 meters.

21 The centrifugal pump acts as a reversed of an inward radial flow reaction turbine. This means that the flow in centrifugal pumps is in the radial outward directions the centrifugal pump works on the principle of forced vortex flow which means that when a certain mass of liquid is rotated by an external torque, the rise in pressure head of the rotating liquid is proportional to the square of tangential velocity of the liquid at that point. Rise in pressure head).thus at the outlet of the impeller, where radius is more, the rise in pressure head will be more and the liquid will be discharged at the outlet with a high pressure head. Due to this high pressure head, the liquid can be lifted to a high level. Main parts of a centrifugal pump Impeller Casing Suction pipe with a foot valve and a strainer Delivery pipe All the main parts of the centrifugal pump. (1) IMPELLER: The rotating part of a centrifugal pump is called impeller. it consists of a series of backward curved vanes.the impeller is mounted on a shaft which is connected to the shaft of an electric motor. (2) CASING: The casing of centrifugal pump is similar to the casing of reaction turbine. it is an air tight passage surrounding the impeller and is designed in such a way that the kinetic energy of the water discharged at the outlet of the impeller is converted into pressure energy before the designed in such a way that the kinetic energy of the water discharged at the outlet of the impeller is converted into pressure energy

22 before the water leaves the casing and enters the delivery pipe. Suction pipe with a pipe whose one end is connected to inlet and then other to tank. (3)SUCTION PIPE FOOT VALVE: Delivery valve to flow control valve open only in upward direction.a strains is filled at lower end of the sump P.M.D.C MOTOR: The permanent magnet direct current motor ( P.M.D.C) is a 12v dc motor. In any electric motor, operation is based on simple electromagnetism. A currentcarrying conductor generates a magnetic field; when this is then placed in an external magnetic field, it will experience a force proportional to the current in the conductor, and to the strength of the external magnetic field. D.C MOTOR: The d.c generators and d.c motors have the same general construction. MOTOR PRINCIPLE: An electric motor is a machine which converts an electrical energy to mechanical energy. All D.C machines have five principal components viz (i) Field system (II) armature core (iii) armature winding (iv) Commutator (v) brushes (ii) Field system: The function of the field system is to produce Uniform field within which the armature rotates.it consists of a number of salient poles(of course, even number) bolted to the inside of circular frame (generally called yoke).the yoke is usually made of solid cast steel whereas the pole piece are composed of stacked laminations.

23 Field coils are mounted on the poles and carry the d.c exciting current. The field coils are connected in such a way that adjacent poles have opposite polarity. The m.m.f. developed by the coils produces a magnetic flux that passes through the pole pieces, the air gap, the armature and the frame. Practical d.c machines have air gaps ranging from 0.5mm to 1.5mm.since armature and field systems are composed of materials that have permeability, most of the m.m.f.of field coils is required to set up flux in the air gap. By reducing the length of air gap, we can reduce the size of field coils (number of turns). (iii) Armature core: The armature core is keyed to the machine shaft and rotates between the field poles. It consists of slotted soft-iron laminations (about 0.4 to 0.6mm thick) that are stacked to form a cylindrical core. The laminations are individually coated with a thin insulating film so that they do not come in electrical contact with each other. The purpose of laminating the core is to reduce the eddy current loss. The laminations are slotted to accommodate and provide mechanical security to the armature winding and to give shorter air gap for the flux to cross between the pole face and the armature teeth. (iv) Armature winding: The slots of the armature core hold conductors that are connected in a suitable manner.this are known as armature winding. This is the winding in which working e.m.f. is induced. The armature conductors are connected inseries-parallel: the conductors being connected in series so as to increase the voltage and in parallel paths so as to increase the current. The armature winding of a d.c.machine is a closed circuit

24 winding: the conductors being connected in a symmetrical manner forming a closed loop or series of closed loops. (v) Commutator; A commutator is a mechanical rectifier which converts the alternating voltage generated in the armature winding into direct voltage across the brushes.the commutator is made of copper segments insulated from each other by mica sheets and mounted on the shaft of the machine. The armature conductors are soldered to the commutator segments in a suitable manner to give rise to the armature winding.depending upon the manner in which the armature conductors are connected to the commutator segments, there are tow types of armature winding in a.d.c. machine viz(a) lap winding (b) wave winding. Great care is taken in building the commutator because any eccentricity will cause the brushes to bounce, producing unacceptable sparking.the sparks may burn the brushes and overheat and carbonize the commutator. (vi) Brushes: The purpose of brushes is to ensure electrical connections between the rotating commutator and stationary external load circuit. The brushes are made of carbon and rest on the commutator,the brush pressure is adjusted by means of adjustable springs. if the brush pressure is Very large, the friction produces heating of the commutator and the bruches.on the other hand, if it is too weak, the imperfect contact with the commutator may produce sparking.

25 STATOR: The stator is the stationary part of an electric generator or electric motor. The non-stationary part on an electric motor is the rotor. Depending on the configuration of a spinning electromotive device the stator may act as the field magnet, interacting with the armature to create motion, or it may act as the armature, receiving its influence from moving field coils on the rotor. The first DC generators (known as dynamos) and DC motors put the field coils on the stator, and the power generation or motive reaction coils are on the rotor. This was necessary because a continuously moving power switch known as the commutator is needed to keep the field correctly aligned across the spinning rotor. The commutator must become larger and more robust as the current increases. The stator of these devices may be either a permanent magnet or an electromagnet. Where the stator is an electromagnet, the coil which energizes it is known as the field coil or field winding. ROTOR: The rotor is the non-stationary part of a rotary electric motor or alternator, which rotates because the wires and magnetic field of the motor are arranged so that a torque is developed about the rotor's axis. In some designs, the rotor can act to serve as the motor's armature, across which the input voltage is supplied. ELECTROMAGNETIC COIL: An electromagnetic coil is formed when a conductor solid copper wire is wound around a core or form to create an inductor or electromagnet. One loop of wire is usually referred to as a turn, and a coil consists of one or more turns. For use in an electronic circuit, electrical connection terminals called taps are often

26 connected to a coil. Coils are often coated with varnish and/or wrapped with insulating tape to provide additional insulation and secure them in place. A completed coil assembly with taps etc. is often called a winding. A transformer is an electromagnetic device that has a primary winding and a secondary winding that transfer s energy from one electrical circuit to another by magnetic coupling without moving parts. The term tickler coil usually refers to a third coil placed in relation to a primary coil and secondary coil. A coil tap is a wiring feature found on some electrical transformers, inductors and coil pickups, all of which are sets of wire coils. The coil tap are points in a wire coil where a conductive patch has been exposed. As self induction is larger for larger coil diameter the current in a thick wire tries to flow on the inside. The ideal use of copper is achieved by foils. Sometimes this means that a spiral is a better alternative. Multilayer coils have the problem of interlayer capacitance, so when multiple layers are needed the shape needs to be radically changed to a short coil with many layers so that the voltage between consecutive layers is smaller.

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28 DESIGN OF EQUIPMENT AND DRAWING MACHINE COMPONENTS The SOLAR AIR COLLER consists of the following components to full fill the requirements of complete operation of the machine. 1. Fan 2. Moto DESIGN CALCULATION PUMP CALCULATION: 1. To find out the power required to drive the pump 2. To find the flow rate of pump a) flow rate Continuity equation, Q= Area of pump shaft x Velocity Dia of pump shaft(d) =15mm Dia of outlet of the pump (d) =3mm Speed of the pump shaft =3000rpm Area = π x d 2 /4 = π x (0.003) 2 /4 = 7.06 x 10-6 m 2 Velocity= π x D x n / 60 = π x x 3000/60 =2.35 m/s

29 Therefore, Q = 7.06 x 10-6 m 2 x 2.35 m/s b) To find power = m 3 / min i) Power = force X velocity ii) Force = pressure X area iii) Pressure =ρ X g X h ρ = density of water =1000Kg/m 2 g = acceleration due to gravity =9.81 m/s 2 h = water head 3m 1kg =10N Pressure =ρ X g X h =1000X10 X9.81X3 = 2.9X10 5 N/m 2 p = 2.9 bar Pressure =F/A F =P/A F =2.9X10 5 x π/4 x (d) 2 =2.9 X10 5 x π/4 x (3X10-3 ) 2 = 2.05 N Power = force X velocity =2.05 X2.35 = 4.8 W Therefore power required to pump 4.8w

30 DRAWING

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33 WORKING PRINCIPLE Hot water flows to the main sewer of the water distribution system. Then, the water is distributed through a pipe system to spray nozzles. Nozzles cause the dispersion of the water onto the wet deck surface, thus creating water film of large contact surface. The water coming off the lower edges of the wet deck surface falls down in the form of droplets to the cooled water tank, from where it is pumped back to the cooled equipment. The process of water cooling occurs mainly as the result of the evaporation of a small amount of cooled water to the air stream (transport of mass), making the use of the heat of phase transition (heat of vaporization), which is collected from the water stream and to a lesser extent as the result of convective heat transfer form water to air (heat transfer) Counter-current air flow in the cooling tower is inducted by the suction produced by the axial fan with a capacity adapted to the required cooling parameters. The fan is mounted inside the enclosure on the roof of the cooling cell. The air is sucked into the cell through inlet ports equipped with shutters, which protect the system from sucking things such as foliage and from splashing cooled water outside the cooling tower. Then, the sucked air flows through the rain zone under the wet deck surface, through the fill, splash zone above the wet deck surface and then it undergoes the process of mist elimination, which minimizes water loss resulting from dissipation of droplets. The heated and moisten air flows through the fan, and then it is blown away outside through the upper section of the fan casing to the environment.

34 . MERITS

35 MERITS Low cost High reliable Low maintenance Simple in design

36 APPLICATIONS

37 APPLICATIONS Energy savings Reduce maintenance requirements (personnel and equipment replacement costs) Precisely control process water temperature stabilization

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39 LIST OF MATERIALS FACTORS DETERMINING THE CHOICE OF MATERIALS The various factors which determine the choice of material are discussed below. 1. Properties: The material selected must posses the necessary properties for the proposed application. The various requirements to be satisfied Can be weight, surface finish, rigidity, ability to withstand environmental attack from chemicals, service life, reliability etc. The following four types of principle properties of materials decisively affect their selection a. Physical b. Mechanical c. From manufacturing point of view d. Chemical The various physical properties concerned are melting point, thermal Conductivity, specific heat, coefficient of thermal expansion, specific gravity, electrical conductivity, magnetic purposes etc. The various Mechanical properties Concerned are strength in tensile, Compressive shear, bending, torsional and buckling load, fatigue resistance, impact resistance, eleastic limit, endurance limit, and modulus of elasticity, hardness, wear resistance and sliding properties.

40 The various properties concerned from the manufacturing point of view are, Cast ability Weld ability Surface properties Shrinkage Deep drawing etc. 2. Manufacturing case: Sometimes the demand for lowest possible manufacturing cost or surface qualities obtainable by the application of suitable coating substances may demand the use of special materials. 3. Quality Required: This generally affects the manufacturing process and ultimately the material. For example, it would never be desirable to go casting of a less number of components which can be fabricated much more economically by welding or hand forging the steel. 4. Avilability of Material: Some materials may be scarce or in short supply.it then becomes obligatory for the designer to use some other material which though may not be a perfect substitute for the material designed.the delivery of materials and the delivery date of product should also be kept in mind. 5. Space consideration: Sometimes high strength materials have to be selected because the forces involved are high and space limitations are there.

41 6. Cost: As in any other problem, in selection of material the cost of material plays an important part and should not be ignored. Some times factors like scrap utilization,appearance,and non-maintenance of the designed part are involved in the selection of proper materials. S.No DESCIRPTION QTY Material 1 fan 1 Ms 2 Dc pump 1 Moulded plastic 3 Pipe line 1 plastic

42 COST ESTIMATION

43 COST ESTIMATION 1. MATERIAL COST. S.No DESCRIPTION QTY MATERIAL AMOUNT (Rs) 1. battery 1 plastic fan 1 M.S Dc pump 1 Moulded plastic TOTAL COST: Total cost = Material Cost +Labour Cost +Overhead Charges = =5300 /- Total cost for this project (Rs)=5300/-

44 CONCLUSION

45 CONCLUSION This article demonstrates rather pointedly that cooling tower performance and operation are not so straightforward as they many times are thought to be. These mi sconceptions and inadequate knowledge of cooling tower design can cost you mone y in all phases of dealing with cooling towers. Purchase of a new tower will cost mor e in the long run if plant operations do not run efficiently due to an illdesigned cooling tower. Tower operation, in terms of energy cost, will be more expensive if utilization of fan power is misunderstood. Upgrading an existing tower may turn out to be futile because tower performance was viewed in terms of range. It is necessary to have a working knowledge of the performance of cooling towers, without misconception, in order to purchase andoperate them to the best advantage for maximum production a t minimum cost.

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47 BIBLIOGRAPHY Strength of Materials -R.S.Kurmi Manufaturing Technology -M.Haslehurst. Design of machine elements -R.s.Kurumi

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