Unit-1.pptx
- 1. Dr. Mahalingam College of Engineering and Technology, Pollachi-03 Department of Civil Engineering V Semester 19CEEN1004 – Building Services Unit-1 Machineries Prepared by K. Srinivasan, AP(SS)/Civil 1 Dept of Civil Engineering 19CEEN1004 – Building Services
- 2. Unit-1 Syllabus 2 Dept of Civil Engineering 19CEEN1004 – Building Services
- 3. Topic : Hot Water Boilers Lecture Number : 01 Course Outcome: CO1: Explain the different types of machineries used for servicing the buildings. Learning Outcome: LO1: Describe the functions of hot water boilers with sketch. Specific Outcome: SO1: List the types of hot water boilers. SO2: List the functions of hot water boilers. SO3: Describe the functions of hot water boilers with sketch. Reference: R. Udayakumar, "A text book on Building Services", Eswar Press, Chennai, 2011. Pg. No.: 1-9 3 Dept of Civil Engineering 19CEEN1004 – Building Services
- 4. Boilers and its Classification • Boilers: convert water into steam under high pressure by using heat. Also called steam generator. Works at greater pressure than atmospheric pressure. • Classification: Boilers Flow of water & hot gases Fire tube Water tube Axis of the shell Vertical Horizontal Position of the furnace 4 Dept of Civil Engineering 19CEEN1004 – Building Services Externally fired Internally fired Application Stationery Mobile Steam Pressure Low Medium High
- 5. Accessories of Boiler 5 Dept of Civil Engineering 19CEEN1004 – Building Services • Water Gauge – used to check level of water in boiler • Pressure Gauge – to check the pressure inside the boiler • Safety Valve – release the excess steam • Fusible Plug – made of gun metal. • Feed check Vale – control flow of water into boiler • Steam stop valve - control the supply of steam • Blow-off cock – Used to clean the boiler bottom
- 6. Fire Tube Boiler 6 Dept of Civil Engineering 19CEEN1004 – Building Services • Several types depending upon requirement. • We are going to see Cochran Boiler. • Cylinder held a vertical with flat base & hemispherical shell at top.
- 7. Working of Fire Tube Boiler 7 Dept of Civil Engineering 19CEEN1004 – Building Services • Water is filled upto safe level. • Coal is burnt in grater. • Hot air is passed through fire tube. • Water will get converted to steam. • When water level is low fusible plug melts and put down the fire • Water gauge and pressure gauge measure water level & steam pressure • Safety valve release excess steam. • Steam valve to regulate the flow of steam. • Manhole, fire hole and inspection chamber is used for maintenance.
- 8. Water Tube Boiler • Babcock and Wilcox Boiler. • Cylindrical drum L-8m & D-2m • Water tubes at 10o to 15o one end connected to uptake header & other to down comer. 8 Dept of Civil Engineering 19CEEN1004 – Building Services
- 9. Working of Water Tube Boiler 9 Dept of Civil Engineering 19CEEN1004 – Building Services • Half of the cylinder is filled with water. • The wet steam is collected in anti priming tube and is super heated by super heater pipe. • Steam and hot water move in uptake header and water from cylinder comes to downtake header.
- 10. Water Tube boiler 10 Dept of Civil Engineering 19CEEN1004 – Building Services
- 11. High Pressure Boilers • Lamont Boiler • Generate pressure greater than 85kgf/cm2 • Modern power pants use this boiler – high thermal efficiency • Water tube boilers are used as high pressure boilers • Water is kept under pressure by centrifugal pump – steam turbine • Rate of heat transfer and evaporation capacity is increased 11 Dept of Civil Engineering 19CEEN1004 – Building Services
- 12. Working of high pressure boiler 12 Dept of Civil Engineering 19CEEN1004 – Building Services • Water supplied by feed pump into economiser and it moves into water steam drum. • Preheating – reduces the thermal stress in boiler • Water enters circulating pump and it is pumped into evaporator • Wet steam is passed to convection super heater to remove moisture. • Due to high pressure of steam temperature is also high.
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- 14. Topic : Vibrators & Concrete Mixers Lecture Number : 04 Course Outcome: CO1: Explain the different types of machineries used for servicing the buildings. Learning Outcome: LO5: Explain the functions of vibrator with sketch. LO6: Explain the functions of concrete mixers with sketch. Specific Outcome: SO1: Explain the functions of vibrator with sketch. SO2: Explain the functions of concrete mixers with sketch. Reference: R. Udayakumar, "A text book on Building Services", Eswar Press, Chennai, 2011. Pg. No.: 1-9 14 Dept of Civil Engineering 19CEEN1004 – Building Services
- 15. Salient Features of Vibrators • Powered by electric motor or internal combustion engine or compressed air motor. • Needle should not get damaged during compacting, it will affect bearings. • IS 2505-1992 • Capacity and geometric requirement of vibrator depend on various requirement. • Compacting factor 0.75-0.85 & stiff concrete. • Frame work joints should be tight. • Vibrators may be used vertically, horizontally and at an angle. • The vibrating or active part should be dipped fully in concrete. 15 Dept of Civil Engineering 19CEEN1004 – Building Services
- 16. Salient Features of Vibrators • No of points of insertion – range of action overlap & degree of compaction is recognized from rising of air bubbles. • Speed of insertion- 3cm/s & withdrawn slowly • New filling of concrete – vibrated within an hour • Time required is judged by experienced operator • Over vibration should be avoided • Re-vibration is beneficial. 16 Dept of Civil Engineering 19CEEN1004 – Building Services
- 17. Concrete Mixer • Used to mix ingredients of concrete to prepare fresh concrete • Components of mixer are drum with blades or baffles, drum is allowed to rotate at an angle. • Aggregate is added by power operator and rotated with water for 1.5 to 2 minutes. • Tilting the drum the wet concrete is discharged and it need to placed within 30 minutes. 17 Dept of Civil Engineering 19CEEN1004 – Building Services
- 18. Classification of concrete mixers • Continuous mixer – used for massive projects like dams, bridges – requires continuous flow of concrete. • Batch mixer or drum mixer – used for ordinary buildings Tilting mixers – 85T, 100T, 140T & 200T – emptied by tilting of drum Non-tilting mixers – 200NT, 240NT,280NT,400NT&800NT – emptied by chute Reversing mixers – 200R, 280R, 340r & 400R- emptied by reversing 18 Dept of Civil Engineering 19CEEN1004 – Building Services
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- 20. Features to be considered: 20 Dept of Civil Engineering 19CEEN1004 – Building Services • Water should be added to drum before adding ingredients. • Output depend on time of mixing, No. of batches per hour, size of mixer and condition it operates. • Upto 800litres mixing time is 1.5 to 2 minutes, it should be taken after adding all ingredients. • Speed of rotation specified by manufacturer. • After each mix discharge drum should be washed with water • Quantity produced should be such that it can be placed within 30 minutes. • Mixed material should not exceed 60% of drum volume.
- 21. Topic : Motor Lecture Number : 06 Course Outcome: CO1: Explain the different types of machineries used for servicing the buildings. Learning Outcome: LO7: Explain the functions of DC and AC Motor with neat sketch. Specific Outcome: SO1: Explain the functions of DC motor with sketch. SO2: Explain the functions of DC with sketch. Reference: R. Udayakumar, "A text book on Building Services", Eswar Press, Chennai, 2011. Pg. No.: 20-27. 21 Dept of Civil Engineering 19CEEN1004 – Building Services
- 22. Motor • Electromechanical device that converts electrical energy to mechanical energy. • Mechanical energy used to e.g. • Rotate pump impeller, fan, blower • Drive compressors Lift materials • Motors in industry: 70% of electrical load. 22 Dept of Civil Engineering 19CEEN1004 – Building Services
- 23. Working Principle 23 Dept of Civil Engineering 19CEEN1004 – Building Services
- 24. Structural Design 24 Dept of Civil Engineering 19CEEN1004 – Building Services
- 25. Classification of Motors 25 Dept of Civil Engineering 19CEEN1004 – Building Services
- 26. Flemings Left Hand Rule 26 Dept of Civil Engineering 19CEEN1004 – Building Services
- 27. DC Motor 27 Dept of Civil Engineering 19CEEN1004 – Building Services
- 28. DC Motor 28 Dept of Civil Engineering 19CEEN1004 – Building Services
- 29. Advantage and disadvantage 29 Dept of Civil Engineering 19CEEN1004 – Building Services • Advantage • High starting torque • Quick starting, stopping, reversing and accelerating • Accurate stepless speed control with constant torque • Disadvantage • High initial cost of motor and control gear • Increased operational cost and maintenance cost because of commutators and brush gear.
- 30. AC Motor 30 Dept of Civil Engineering 19CEEN1004 – Building Services • Electrical current reverses direction • Two parts: stator and rotor • Stator: stationary electrical component • Rotor: rotates the motor shaft • Two types • Synchronous motor • Induction motor
- 31. AC Motor 31 Dept of Civil Engineering 19CEEN1004 – Building Services
- 32. Induction Motor 32 Dept of Civil Engineering 19CEEN1004 – Building Services • Induction motors can be classified into two main groups: • single-phase induction motors • three-phase induction motors • Single-phase induction motors: • These only have one stator winding, operate with a single-phase power supply. • Three –phase induction motors: • The use three sets of stator coils the rotating magnetic field drags the rotor around with it.
- 33. Synchronous motor 33 Dept of Civil Engineering 19CEEN1004 – Building Services • As the name suggests Synchronous motors are capable of running at constant speed irrespective of the load acting on them. • Synchronous motors have got higher efficiency than its counterparts. Its efficiency ranges from 90 – 92%.
- 34. Construction of induction motor 34 Dept of Civil Engineering 19CEEN1004 – Building Services • Induction motor consists of two major parts namely • Stator • Rotor • Stator – consists of outer body with end cover which supports bearings of rotor, - Inner surface consist of pole core, pole coil and pole shoe • Rotor – laminated steel sheets assembled around the shaft. Winding is placed near periphery of the rotor.
- 35. Working of induction motor 35 Dept of Civil Engineering 19CEEN1004 – Building Services • Working is similar to DC motor • Instead of DC supply AC supply is given • AC supply is given to stator (pole coil) and rotor(Armature). • Pole coil produces magnetic field which interlinks with the magnetic field produced by the winding in rotor. • A torque is produced which rotates the rotor.
- 36. Advantages of AC Motor 36 Dept of Civil Engineering 19CEEN1004 – Building Services • Simple design • Rugged construction • Reliable operation • Low initial cost • Easy operation • Simple maintenance • Simple gear control for starting and speed control • High efficiency
- 38. AC Motor Vs DC Motor 38 Dept of Civil Engineering 19CEEN1004 – Building Services
- 39. AC Motor Vs DC Motor 39 Dept of Civil Engineering 19CEEN1004 – Building Services
- 40. Topic : Generators Lecture Number : 07 Course Outcome: CO1: Explain the different types of machineries used for servicing the buildings. Learning Outcome: LO8: Explain the functions of DC and AC Generator with neat sketch. Specific Outcome: SO1: Explain the basic principle of Generator SO2: Explain the functions of DC generator with sketch. SO3: Explain the functions of AC generator with sketch. Reference: R. Udayakumar, "A text book on Building Services", Eswar Press, Chennai, 2011. Pg. No.: 27-30. https://www.slideshare.net/selvankarthik/generators-107966751?from_action=save 40 Dept of Civil Engineering 19CEEN1004 – Building Services
- 41. Introduction 41 Dept of Civil Engineering 19CEEN1004 – Building Services • A generator is a device that converts motive power (mechanical energy) into electrical power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines and even hand cranks. • Generators can be DC(Dynamo) andAC (Alternator). • Generators provide nearly all of the power for electric power grids. • All charging circuits operate in three stages: • During starting, battery supplies all load current • During normal operation, generator supplies all current and recharges the battery • During peak operations, battery helps generator to supply current • Both of these generators produce electrical power, based on same fundamental principle of Faradays`s law of electromagnetic induction.
- 42. Working Principle 42 Dept of Civil Engineering 19CEEN1004 – Building Services • Generator works based on : 1. Faradays law of Induction 2. Flemings right hand rule • Faraday's law of induction is a basic law of electromagnetism predicting how a magnetic field will interact with an electric circuit to produce an electromotive force (EMF)—a phenomenon called electromagnetic induction. It is the fundamental operating principle of transformers, inductors, and many types of electrical motors, generators and solenoids.
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- 44. DC Generator 44 Dept of Civil Engineering 19CEEN1004 – Building Services • Agenerator which produces direct current is called as a dynamo. In the past the dynamo was the only convenient way to generate electrical energy • Principle and Working: •If a conductor cuts magnetic lines of force, electromagnetic force is generated in the conductor, and that the electromagnetic force produced will vary with the number of magnetic lines of force, number of conductors (number of coil windings), and the speed at which the conductor cuts the lines of magnetic. Produced current is collected by using external circuit
- 45. • If a conductor is turned clockwise between the N and S poles of a magnet, electromotive force will be generated in the arrow direction in accordance with Flemings right hand rule 45 Dept of Civil Engineering 19CEEN1004 – Building Services
- 46. Construction 46 Dept of Civil Engineering 19CEEN1004 – Building Services • The generator is comprised of the poles cores, filed coils, armature , brushes , pulley and frame. • Pole cores- Poles cores become the N and S poles of magnet when the current • flow through field coils. Most of generator have four poles • Field coils- It is insulates wire wound in coil form and installed around the pole core. The current flows through the field coils • Armature- It is a shaft rotates inside the pole cores and produce the electromotive force. It is comprised of a rotating shaft with the armature coil at the centre and the commutator at one end. The commutator serves to convert theAC to DC • Brushes- The brushes contact against the commutator and serve to pass the current generated in the armature to the field coil and to the outside of the generator • It is made up on carbon • Pulley- It is provided with a fan to cool the generator
- 47. DC Generator Characteristics 47 Dept of Civil Engineering 19CEEN1004 – Building Services • Electromagnetic force generated by the generator grows larger with greater amount of flux • For these reasons, continued high speed operation will cause large current to flow through the battery, generator and other circuits and shorten their service life • On the other hand , during low speed only small current will flow • To prevent such condition, a regulator is provided
- 48. Control unit (Regulator) It consists of three relays : V oltage regulator to control the generated voltage Acurrent limiter to control the output current Acut-out relay to prevent reverse flow of current from the battery 48 Dept of Civil Engineering 19CEEN1004 – Building Services
- 49. ALTERNATOR (AC Generator) 49 Dept of Civil Engineering 19CEEN1004 – Building Services • The increasing numbers of accessories also consume a large amount of power we need to generate more power. • But DC Generator capacity is only limited to over come this problemAlternator is used • Alternator is the heart of the vehicles electrical system when the engine is running. It uses electromagnetism to change some of the engines mechanical energy into electrical energy • Two types alternators – Conventional and separate voltage regulator type • In recent, In built regulator alternator is used • Amps rating- 40 to 80 amps
- 50. Construction 50 Dept of Civil Engineering 19CEEN1004 – Building Services • The alternator is comprised primarily of the stator, rotor, bracket, rectifier(silicon diodes) and brushes. • Stator- It has three sets of armature coils wound on it to induce a three phase current. • Rotor- Rotors can be classified into the salient pole type and Randell type.At present randell is mostly used. In this type the number of poles is equal to the numbers of finers • Bracket- The end bracket opposite to the pulley side has six diodes assembled into it that serve to rectify all of the three phaseAC generated • Brushes -It serves to pass a current of 2 to 3 amperes to the rotor coils. In alternator the main current does not flow through these brushes
- 51. • Rectifier-Alternator produce three phaseAC but the automobile charging system need DC supply. ConvertingAC to DC is called rectification. Rectification can be done in several ways but efficient way is using diode 51 Dept of Civil Engineering 19CEEN1004 – Building Services
- 52. Working 52 Dept of Civil Engineering 19CEEN1004 – Building Services • An alternator is designed to change mechanical energy into electrical energy • The working principle of an alternator is an electromagnetic induction (EMI) • When the rotor spins, its strong magnetic filed cuts across the stator windings. This induces current in the stator windings • If the stator winding are connected to a load(Ex- bulb), the load would operate • Slip rings are used
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- 54. Advantage: 54 Dept of Civil Engineering 19CEEN1004 – Building Services • Rotor has high strength against speed • Good rectifying characteristics • Current limiter not required depending on the design • Cut-out relay not required • Charging is possible while idling