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Ing de Producto AIF Entrenamiento Básico. Fundamentos de Aire Comprimido.

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Presentación del tema: "Ing de Producto AIF Entrenamiento Básico. Fundamentos de Aire Comprimido."— Transcripción de la presentación:

1 Ing de Producto AIF Entrenamiento Básico

2 Fundamentos de Aire Comprimido

3 Ing de Producto AIF Entrenamiento Básico Life Cycle Cost of an air compressor Energy consumption Installation Maintenance Investment Why are we here? Compressed Air Fundamentals

4 Ing de Producto AIF Entrenamiento Básico Ciclo del costo de la vida de un compresor l De las tres categorías del costo la energía puede ser arriba del 90% en dias años de trabajo de un equipo l de hecho dentro de los primeros 12 meses, el costo de inversion es exedido por el costo del uso de la máquina l Comprar un compresor representa el más bajo de los tres costos l El consumo de energía es por mucho el costo más significante en la operación de un equipo Inversión Instalacion Mantenimiento Consumo de Energía Fundamentos del aíre comprimido

5 Ing de Producto AIF Entrenamiento Básico Fundamentos del aíre comprimido Que es el Aire Comprimido?

6 Ing de Producto AIF Entrenamiento Básico l Nosotros vivimos en el fondo de un mar llamado Atmosfera Fundamentos del aíre comprimido

7 Ing de Producto AIF Entrenamiento Básico l El aíre es como un sobre gaseoso que rodea la tierra ejerciendo una presión en cada cosa l La presión actual depende de la localización con respecto al mar. Fundamentos del aíre comprimido

8 Ing de Producto AIF Entrenamiento Básico l Al nivel del mar la presión atmosférica es de 14.7 psiA l psiA: Libras por pulgada cuadrada (Absolutas) Fundamentos del aíre comprimido

9 Ing de Producto AIF Entrenamiento Básico l a 500 pies bajo el nivel del mar, la presión del aire es psiA Fundamentos del aíre comprimido

10 Ing de Producto AIF Entrenamiento Básico l En la cima de una montaña de 5000 pies, la presión del aíre es sólo de 12.2 psiA l La Montaña del Everest esta a 29,000 pies sobre el nivel del mar, la presión sólo es de 4.56 psiA Fundamentos del aíre comprimido

11 Ing de Producto AIF Entrenamiento Básico l Comprimir: Forzar a que entre todo en un espacio más pequeño l Aire: Es una mexcla incolora, inolora, e insipida, principalmente nitrogeno (78%) y oxygeno (21%) l Cuando se Controla, el aire comprimido puede ser usado para ejecutar un trabajo Fundamentos del aíre comprimido

12 Ing de Producto AIF Entrenamiento Básico El aíre Comprimido guardado es energía... l La energía contenida dentro de un globo es igual a la energía que se requirió para inflarla. l Si el volume de una cantidad dada de aíre decrece, la presión se incrementará l Con un compresor de desplazamiento positivo, el aire comprimido se obtiene forzando a que este permanezca en un volume más pequeño. Fundamentos del aíre comprimido

13 Ing de Producto AIF Entrenamiento Básico Porque la industria necesita aíre comprimido? l Por la energía: El aíre comprimido es un excelente medio para guardar y transmitir energía para hacer cualquier trabajo. l Por requerimientos de Procesos: El aíre comprimido es una parte activa de procesos (ejem. quimica, farmaceutica, fermentación, etc.) Fundamentos del aíre comprimido

14 Ing de Producto AIF Entrenamiento Básico La energía del aíre l La energía del aíre comprimido es usda para impulsar equipos neumáticos en la producción Ù Ejemplos.--motores de aíre, actuadores, instrumentacion, herramientas, etc. l Para enfriar componentes o partes durante la fabricación l Para soplar basura l etc Fundamentos del aíre comprimido

15 Ing de Producto AIF Entrenamiento Básico Aire de Proceso l El aíre comprimido es una parte integral de un proceso, Ù Quimicos Ù farmaceuticos Ù Comidas y Bebidas Aeración y agitación Ù Semiconductores y Electronicos Ù Aire de respiración medica Fundamentos del aíre comprimido

16 Ing de Producto AIF Entrenamiento Básico Definiciones Presión Absoluta Es La Suma de la presión medida+la presión atmosférica (100 psig psia = psia absolutos) Relación de Compresión La relación de la presión absoluta de salida entre la presión absoluta de entrada (100 psiG psiA) / 14.2 psiA = 8.04 ratios), ó simplemente son las veces las cuales se reduce el volume de un gas a determinada presión a un volumen menor a una presión mayor

17 Ing de Producto AIF Entrenamiento Básico Punto de Rocío Es la temperatura de un gas a una presión dada, a la cual el vapor de agua comienza a condensarse Capacidad Cantidad de un gas entregado, típicamente se refiere a las condiciones de entrada, que son humedad, presión y tempertura ejemplos: ACFM,ICFM, SCFM, Free air CFM, FAD Aire Estandard (Ejemplo SCFM) Un volume dado de aíre definido una especifica, o estandard condicion. Los parametros comunmente aceptados en la industria como estándar son: 14.7 psiA, 60 o F, 0% RH Definitions

18 Ing de Producto AIF Entrenamiento Básico Compresor Dinámico El aumento de energía se obtiene convirtiendo la energía cinética en energía de presión, aumentando primero la velocidad de las partículas y después desacelarandolas Desplazamiento Positivo Un volume de aíre es atrapado dentro de un espacio cerrdo. El volume es reducido causando un aumento de presión (compresion) Definiciones

19 Ing de Producto AIF Entrenamiento Básico Interenfriamiento El enfriamiento de un gas entre etapas de compresión 1.Reduciendo la temperatura 2.Reduciendo el volume para la siguiente etapa 3.Licuando vapores condensables para reducir los HP (Todo lo relacionado para reducir los HP) Definiciones

20 Ing de Producto AIF Entrenamiento Básico Formulas Cambio de Presión vs Cambio de BHP (potencia) Para compresores de Desplazamiento positivo: Un cambio de presión de 1 psig requiere un aumento de potencia del.5%. Ejemplo: un compresor de 1000 CFM requiere 200 BHP para 100 psiG. El mismo compresor, operando a la misma velocidad requerira (200 x 1.10) = 220 BHP para llegar a 120 psiG Cálculo del costo de potencia--para un año de operación BHP X.746 kW X $ X Oper. Hrs = Oper. $ Mtr. Eff. HP kWh Year Year

21 Ing de Producto AIF Entrenamiento Básico 20 BHP X.746 kW X $.09 X 8700 Hrs. = $12,560.93% Eff. Mtr. HP kWh Year Porque debo operar mi compresor a la más baja presión posible? ¡Sólo vea el ejemplo anterior! Ejemplo - Para el compresor anterior el costo del incremento de presión de 100 a 120 psiG. Es el siguiente: Formulas

22 Ing de Producto AIF Entrenamiento Básico Para cálculos de aíre comprimido se requieren fórmulas termodinámicas. En el sistema de mediciones Ingles, se utilizan las fórmulas siguientes para cálculos termodinámicos La presión se expresa en Libras por pulgadas Cuadrada (psi, or lb/in 2 ). La temperatura se expresa en Fahrenheit (deg. F.) El volume se expresa en pies cúbicos (Ft 3 ) Volume Flow Rate is expressed in cubic feet / min (Ft 3 /min) Formulas

23 Ing de Producto AIF Entrenamiento Básico Relaciones de Presión l Todos los cálculos se basan en valores absolutos para Temp. Y Presión. l Presión Absoluta (psiA) = Presión en medida (psiG) + Presión barométrica(ambiente). sEjemplo: 14.7 psiA Presión Barométrica 100 psiG Presión de descarga = psiA Presión absoluta de descarga. Formulas

24 Ing de Producto AIF Entrenamiento Básico Relación de Compresión Relación de Compresión =Presión Absoluta de Descarga Presión absoluta de entrada ó Medio Ambiente Recuerdese: Presión absoluta de descarga = Presión de descarga medida + (Presión barométrica ó ambiental (psiA) Example: 14.7 psiA Presión de entrada 125 psiG Presión de descarga La Relación de Compresion es = ( ) / 14.7 = 9.5 Formulas

25 Ing de Producto AIF Entrenamiento Básico Flujo de volume Del Ejemplo anterior: Si un compresor de 100 CFM toma 100 CFM de aíre del medio ambiente y lo comprime a 125 psiG. El aíre a sido prensado 9.5 de su tamaño original, y ahora sólo ocupa pies cubicos en su estado comprimido. Relación de Compresión = ( ) / 14.7 = pies Cúbicos / 9.5= pies cúbicos Ratings Si la Relación de Compresión del compresor = 9.5 este estará operando en el límite

26 Ing de Producto AIF Entrenamiento Básico La presión barométrica decrece incrementando la altitud y viceversa. Basandonos en una presión de descarga fija la relación de compresión se incrementa si se aumenta la altitud. –Ejemplo: si el mismo compresor se operara ahora a: 3,000 Pies Sobre el nivel del mar = psiA Barometricos Manteniendo la presión de descarga a 125 psiG… –Relación de compresión = ( ) / = 10.5 Se incrementa 100 Pies Cúbicos/10.5 = 9.52 pies cúbicos Se Reduce aún más la masa ó volume comparado con los anteriores Si se sobrepasa la relación de compresión el volume es más reducido, esto ocasionará mayor fuerza para tenderse a liberar si el compresor no está diseñado para esta fuerza se producirá calentamiento ó aumento de temperatura Formulas

27 Ing de Producto AIF Entrenamiento Básico En la industria existen 4 diferentes capacidades para CFM. –Aíre Libre entregado (FAD CFM) –Actual Pies Cúbicos por minuto (ACFM) –Entrada Pies Cúbicos por Minuto (ICFM) –Standard Pies Cúbicos por Minuto (SCFM)

28 Ing de Producto AIF Entrenamiento Básico Aíre libre entregado referido a las condiciones del sitio FAD l/s - cfm External leakage's Aíre libre entregado referido a las condiciones Normal o Standard air External leakage's Scfm Nm 3 /min Flujo Actual referido a las condiciones de entrada del compresor External leakage's Acfm Flujo de entrada Referido a las condiciones de entrada del elemento del compresor External leakage's Im 3 /min - Icfm

29 The face of interaction

30 Ing de Producto AIF Entrenamiento Básico Fundamentos de Aire Comprimido

31 Ing de Producto AIF Entrenamiento Básico THE RIGHT CHOICE COMPRESSOR TYPES WORKING PRINCIPLES CHARACTERISTICS CONTROL SYSTEMS STAGING GENERAL INFORMATION

32 Ing de Producto AIF Entrenamiento Básico THE RIGHT CHOICE COMPRESSOR TYPES WORKING PRINCIPLES CHARACTERISTICS CONTROL SYSTEMS STAGING GENERAL INFORMATION

33 Ing de Producto AIF Entrenamiento Básico The basic principals of air or gas compression

34 Ing de Producto AIF Entrenamiento Básico

35 THE RIGHT CHOICE COMPRESSOR TYPES WORKING PRINCIPLES CHARACTERISTICS CONTROL SYSTEMS STAGING GENERAL INFORMATION

36 Ing de Producto AIF Entrenamiento Básico

37 Reducing the volume of a gas increases its pressure Positive displacement principle

38 Ing de Producto AIF Entrenamiento Básico Oil Free Rotary Screw Element Design

39 Ing de Producto AIF Entrenamiento Básico The Positive Displacement Principle As Applies To Screw The volume of the air or gas is progressively reduced along the length of the screw,causing a pressure increase.

40 Ing de Producto AIF Entrenamiento Básico THE AC ASSYMETRIC PROFILE LOW ROTOR SPEEDS - HIGH BEARING LIFE -LESS WEAR AND TEAR -LOW DYNAMIC AND MECHANICAL LOSS BETTER SEALING - LOW VOLUMETRIC LOSSES-HIGH VOLUMETRIC EFFECIENCY CONTACT POINT AT THE PITCH CIRCLE -NO RELATIVE MOTION BETWEEN ROTORS

41 Ing de Producto AIF Entrenamiento Básico A SCREW IS A POSITIVE DISPLACEMENT MACHINE AND HENCE CAPACITY SPEED -The dynamic and mechanical losses increase with the rotor tip speeds -The volumetric losses decrease -The total losses which are a sum of all losses are minimum at 80 m/s for oil-free elements and approximately 30m/s for lubricated elements Since the total loss curve is almost flat between m/s this range can be employed without much compromise on effeciency

42 Ing de Producto AIF Entrenamiento Básico Compressor Fundamentals

43 Ing de Producto AIF Entrenamiento Básico DYNAMIC COMPRESSOR Dynamic Principle Velocity (Kinetic Energy) converted to pressure

44 Ing de Producto AIF Entrenamiento Básico CENTRIFUGAL COMPRESSORS WORKING PRINCIPLE RADIAL DIFFUSERS INDUCER VANES FLOW CUTS PRESSURE CUTS PRESSURE INCREASE FOLLOWS THE PRINCIPLE OF BERNOULLI P 2 V

45 Ing de Producto AIF Entrenamiento Básico A CENTRIFUGAL IMPELLER

46 Ing de Producto AIF Entrenamiento Básico TURBO WORKING PRINCIPLE Wheel turns Speed of the ball increases Speed suddenly reduced to create pressure increase Blade DIFFUSER

47 Ing de Producto AIF Entrenamiento Básico CENTRIFUGAL COMPRESSOR GENERAL ARRANGEMENT

48 Ing de Producto AIF Entrenamiento Básico THE RIGHT CHOICE COMPRESSOR TYPES WORKING PRINCIPLES CHARACTERISTICS CONTROL SYSTEMS STAGING GENERAL INFORMATION

49 Ing de Producto AIF Entrenamiento Básico GENESIS OF SCREW COMPRESSORS IN THE 1930S COMPRESSED AIR AND GAS USERS HAD TWO MAIN OPTIONS RECIPS AND CENTRIFUGALS  RECIPS WERE POSITIVE DISPL. M/CS WHICH WERE : – THERMODYNAMICALLY STABLE AND POWER SAVING BUT – REQUIRED EXPENSIVE INSTALLATION AND FOUNDATIONS – WERE MAINTENANCE INTENSIVE - EXPENSE/DOWNTIME – CAPACITY FELL WITH USE – LIMITED USE WITH DIRTY GASES CENTRIFUGALS WERE LESS MAINTENANCE INTENSIVE BUT – REQUIRED EXPENSIVE INSTALLATION AND FOUNDATIONS – WERE THERMODYNAMICALLY UNSTABLE – OPERATING BAND WAS LIMITED – SENSITIVE TO DUST AND UNSUITABLE FOR DIRTY GASES – CAPACITY FELL EVEN WITH A FEW MICRON DUST BUILDUP

50 Ing de Producto AIF Entrenamiento Básico GENESIS OF SCREW COMPRESSORS II PROFESSOR LYSHOLM OF THE ROYAL SWEDISH INSTITUTE OF SCIENCE DOING RESEARCH ON COMPRESSORS SET ABOUT FINDING AN IDEAL SYSTEM ON THE FOLLOWING HYPOTHESIS TO OVERCOME WEAKNESSES OF THE RECIPS HIS DREAM MACHINE HAD TO BE A ROTARY WITH NO METAL CONTACT TO OVERCOME DISADVANTAGES OF CENTRIFUGALS IT HAD TO BE A POSITIVE DISPLACEMENT MACHINE THUS WAS BORN THE IDEA OF THE ROTARY SCREW WHICH COMBINED THERMODYNAMIC AND OPERATIONAL STABILITY AND LOW POWER CONSUMPTION WITH UNPARALLELED RELIABIITY

51 Ing de Producto AIF Entrenamiento Básico GENESIS OF SCREW COMPRESSORS III ATLAS COPCO DREW ON THIS BASIC IDEA AND AFTER INTENSIVE RESEARCH COMMERCIALLY INTRODUCED THE U SERIES IN MANY OF THESE MACHINES ARE STILL OPERATING THE WORLD OVER IN THE 1970S THE ATLAS COPCO RESEARCH CENTRE THE CERAC I NSTITUTE IN GENEVA DESIGNED AND PATENTED A REVOLUTIONARY ASSYMETRIC SCREW PROFILE WHICH IS CURRENTLY USED IN THE G AND Z SERIES MACHINES IN THE WORLD TODAY 9 OUT OF 10 MACHINES PRODUCED AND SOLD IN THEIR RANGE ARE ROTARY SCREWS

52 Ing de Producto AIF Entrenamiento Básico CAPACITY Performancecurves COMPRESSOR CHARACTERISTICS COMPRESSOR CHARACTERISTICS POSITIVE DISPLACEMENT COMPRESSOR DYNAMIC COMPRESSOR PRESSURE

53 Ing de Producto AIF Entrenamiento Básico COMPRESSOR CHARACTERISTICS - DYNAMIC MACHINES FLOW PRESSUREPRESSURE SURGE LIMIT SURGE CONTROL AT 25 DEG.C 1 BAR A AT 40 DEG.C 0.97 BAR A POWERPOWER OIL FREE SCREW

54 Ing de Producto AIF Entrenamiento Básico Inlet throttle valve

55 Ing de Producto AIF Entrenamiento Básico Surge Stonewall Flow Pressure DYNAMIC MACHINES- OPERATING BAND

56 Ing de Producto AIF Entrenamiento Básico A DYNAMIC COMPRESSOR OPERATES IN A BAND BETWEENSURGE Breakdown of airflow due to high back pressure (oscillation flow) AND STONE WALL (choke) Maximum flow a compressor can handle at a given speed COMPRESSOR CHARACTERISTICS- DYNAMIC MACHINES COMPRESSOR CHARACTERISTICS- DYNAMIC MACHINES

57 Ing de Producto AIF Entrenamiento Básico Positive displacement compressorsPositive displacement compressors Where:P :Power P 1 :Inlet pressure V 1 : Inlet volume n:Adiabatic factor P 2 /P 1 :Pressure ratio Inlet air temperature and weight flow (density) have no effect on power P = P 1. V 1. {( ) -1 } n n-1 P2P1P2P1 n Variables influencing power: P 1 =Inlet pressure V 1 =Volume flow (not mass!) P 2 /P 1 =Pressure ratio COMPRESSOR CHARACTERISTICS Variables influencing compressor performance

58 Ing de Producto AIF Entrenamiento Básico POWER IS CALCULATED WITH FORMULA: Where:H p :Head pressure m:Mass flow h is : Isentropic efficiency T :Inlet temperature m:Mass flow P 2 /P 1 : Pressure ratio There are three variables that affect the power: COMPRESSOR CHARACTERISTICS COMPRESSOR CHARACTERISTICS Variables influencing dynamic compressor performance P = H p. m h is MASS FLOW IS HIGHER AT LOW TWMPERATURES AS WELL AS HIGH AMBIENT PRESSURES HENCE HIGH POWER CONSUMPTIONS AT THESE CONDITIONS

59 Ing de Producto AIF Entrenamiento Básico COMPRESSOR CHARACTERISTICS - DYNAMIC MACHINES EFFECT OF SPEEDS SINCE A DYNAMIC MACHINE DEVELOPS PRESSURES PROPORTIONAL TO THE SQUARE OF THE VELOCITY REDUCTION IT FOLLOWS THAT IMPELLER SPEED REDUCTION CAUSES A PRESSURE REDUCTION ACCORDING TO THE RELATIONSHIP HENCE DUE TO FREQUENCY REDUCTION OF 3% THE OUTLET PRESSURE REDUCES BY 6% P 2 S

60 Ing de Producto AIF Entrenamiento Básico COMPRESSOR CHARACTERISTICS THERMODYNAMIC INSTABILITY- DYNAMIC MACHINES THERMODYNAMIC INSTABILITY CAN HENCE BE INTERPRETED AS : PRESSURE AND VOLUME ARE INVERSELY RELATED.PRESSURE INCREASE LEADS TO REDUCTION IN VOLUME CAPABILITY OF THE MACHINES. LOWER AIR INLET TEMPERATURE RESULTS IN - SAME VOLUME FLOW FOR HIGH POWER CONSUMPTION - HIGHER MASS FLOW - HIGHER PRESSURE CAPABILITY OF THE MACHINE LOWER SPEEDS RESULT IN VERY LOW PRESSURES THE MACHINE OPERATES WITHIN A NARROW BAND(BETWEEN SURGE AND STONEWALL) THE SYSTEM IS PRONE TO SURGE DUE TO PRESSURE DROPS

61 Ing de Producto AIF Entrenamiento Básico F 1 BALANCED OPPOSED PISTONS FORCE BALANCE 1. HORIZONTAL FORCES F1 BALANCE OUT 2. UNBALANCED VERTICAL FORCES F2 ACTING ALONG WITH THE WEIGHT OF THE PISTON CAUSES CYLINDER OVALITY 3. F2 FORCES ALSO CAUSE AN UNBALANCED COUPLE, NECESSITATING HEAVY FOUNDATIONS. F 2

62 Ing de Producto AIF Entrenamiento Básico WEAR ITEMS - WEAR ITEMS - A COMPARISON WEAR ALONG WITH OVALITY CAUSES A CAPACITY DERATION OF 5-6% PER YEAR,WITHOUT REDUCING THE POWER CONSUMPTION A HIGH NUMBER OF WEAR PARTS INCREASES DOWN TIME AND MANPOWER OUTLAYS VEE BELTS (6) CRANKSHAFTS MAIN BEARINGS (4) BIG END BEARINGS (4) CONNECTING RODS (4) SMALL END BEARINGS (4) CROSS HEADS (4) WIPER RINGS (4 SETS) PISTONS (4) PISTON RINGS (16) CYLINDERS (4) 40 VALVES (SUCTION/DELIVERY) TOTAL 99 WEAR ITEMS 2 GEARS 6 BEARINGS 2 ROTORS TOTAL 10 WEAR ITEMS PISTON SCREW

63 Ing de Producto AIF Entrenamiento Básico P-V DIAGRAM - A COMPARISON CLEARANCE VOLUME CONTRIBUTES TO LOWER VOLUMETRIC EFFECIENCIES AND HIGHER POWER CONSUMPTION PISTONSCREW P V V CV W P W DELIVERY

64 Ing de Producto AIF Entrenamiento Básico. VALVE FLUTTER CAUSES THE AREA OF THE P-V DIAGRAM TO INCREASE WHICH RESULTS IN HIGHER THAN INDICATED POWER CONSUMPTION. FLUTTER IS CAUSED BY WEAR ON THE VALVE PLATES CAUSING AIR TO LEAK IN SMALL CHANNELS.THE PLATES BEGIN TO VIBRATE,SIMILAR TO A REED IN A FLUTE.FLUTTER OCCURS AFTER A SHORT SPAN OF USAGE. PISTON COMPRESSORS EFFECT OF VALVE FLUTTER ON P-V DIAGRAM P V EFFECT OF VALVE FLUTTER w

65 Ing de Producto AIF Entrenamiento Básico PISTON PISTON COMPRESSORS EF PISTON COMPRESSORS EFFECTS OF CYLINDER OVALITY CYLINDER CYLINDER OVALITY PREVENTS RESUMPTION OF CAPACITY TO ORIGINAL LEVEL EVEN WITH NEW RINGS LEADING TO CONTINUED AIR LEAKAGE

66 Ing de Producto AIF Entrenamiento Básico SUITABILITY OF TURBO COMPRESSORS CENTRIFUGAL COMPRESSORS ARE VERY SUITABLE FOR HIGH VOLUME FLOWS ABOVE 6000 M3/HR MASS RELATED PROCESSES LIKE AIR SEPARATION WHERE HIGH POWER AT LOW TEMPERATURES IS COMPENSATED BY HIGH MASS FLOWS. BASE LOAD OPERATION WHERE MACHINE RUNS AT FULL LOAD PRESSURES UPTO 80 BAR

67 Ing de Producto AIF Entrenamiento Básico THE RIGHT CHOICE COMPRESSOR TYPES WORKING PRINCIPLES CHARACTERISTICS CONTROL SYSTEMS STAGING GENERAL INFORMATION

68 Ing de Producto AIF Entrenamiento Básico VERY FEW PROCESSES REQUIRE A CONTINOUS FLOW OF AIR,ALTHOUGH THE DEGREE OF VARIATION CHANGES FROM PROCESS TO PROCESS.THE AIR DEMANDS CAN CHANGE DUE TO DIVERSE CAUSES SUCH AS THE EXTENT OF UTILIZATION OF A FACTORY,ACCORDINDG TO THE DAY OF THE WEEK OR THE TIME OF THE DAY.IT CAN CHANGE DUE TO THE DEGREE OF MATURITY OF A PROCESS,SUCH AS IN FERMENTATION OR OXIDATION PROCESSES.THE MANUFACTURING SET-UP MAY EMPLOY VERY LARGE CONSUMERS OF AIR SUCH AS FORGING HAMMERS,PAINTING BOOTHS,PNEUMATIC PRESSES,ETC.,WHICH RUN OFF AND ON.MASS DEPENDENT PROCESS MAY REQUIRE A FIXED MASS OF AIR,BUT THE MASS FLOW THROUGH THE COMPRESSORS CHANGE WITH THE AMBIENT TEMPERATURES. OR SIMPLY BECAUSE THE AIR DEMAND IS OVER ESTIMATED The compresor therefore requires a control system to regulate the air generation of the compressor in direct relation to the demand

69 Ing de Producto AIF Entrenamiento Básico MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY SUNDAY HOURS AIR DEMAND TYPICAL AIR DEMAND PATTERNS

70 Ing de Producto AIF Entrenamiento Básico SCREW CONTROL SYSTEMS-MODULATION CONTROL AT FULL LOAD THE BUTTERFLY VALVE IS OPEN AND THERE IS FREE FLOW OF AIR.THE MACHINE OPERATES AT THE BUILT-IN PRESSURE RATIO INTAKE 1 BAR A OUTLET 8 BAR A PRESSURE RATIO=8 AT PART LOAD THERE IS A RESTRICTION IN AIR FLOW LEADING TO A VACUUM. HOWEVER OUTLET PRESSURE REMAINS THE SAME SINCE THIS IS DETERMINED BY THE AIR NET PRESSURE VACUUM PREVAILS: INTAKE 1/2 BAR A OUTLET 8 BAR A PRESSURE RATIO IS 16 WHICH IS MUCH HIGHER THAN THE BUILT IN PR.HENCE VERY INEEFECIENT AT PART LOADS IN A MODULATION CONTROL A BUTTERFLY VALVE REGULATES THE INTAKE SCREW ELEMENT * FIGURES ARE USED FOR CONCEPT DEMONSTRATION ONLY

71 Ing de Producto AIF Entrenamiento Básico SCREW CONTROL SYSTEMS LOAD NO-LOAD REGULATION IN A LOAD NO-LOAD CONTROL THE MACHINE RUNS AT EITHER AT FULL LOAD OR UNLOADED IN THE LOADED CONDITION THE INLET VALVE IS COMPLETELY OPEN AND HENCE THE MACHINE MAINTAINS ITS BUILT-IN PRESSURE RATIO IN THE UNLOADED CONDITION THE INLET VALVE IS COMPLETELY CLOSED AND THE OUTLET IS ISOLATED FROM THE AIR NET. POWER CONSUMPTION DROPS ALMOST PROPORTIONATELY DUE TO THE MUCH REDUCED VOLUME FLOW AS WELL AS NO OPERATION ABOVE THE BUILT-IN PRESSURE RATIO

72 Ing de Producto AIF Entrenamiento Básico SCREW CONTROL SYSTEMS VARIABLE SPEED CONTROL IN A VARIABLE SPEED CONTROL,THE SPEED OF THE DRIVE MOTOR IS CONTINOUSLY VARIED TO MATCH THE COMPRESSOR OUTPUT TO THE DEMAND. A SIMPLE SCHEME IS SHOWN BELOW: THE P/I (PRESSURE TO CURRENT CONVERTOR)GENERATES A 4-20 MA SIGNAL DEPENDING ON THE DOWNSTREAM PRESSURE.PRESSURE INCREASE INDICATES A DEMAND REDUCTION.THE VARIABLE SPEED CONTROL (VSD) EMPLOYS THE CURRENT SIGNAL AS THE INPUT,TO REDUCE THE FREQUENCY TO THE DRIVE MOTOR(M). SINCE THE DRIVE MOTOR SPEED IS PROPORTIONAL TO THE SUPPLY FREQUENCY.THE MOTOR SLOWS DOWN.THE REDUCTION IN THE FLOW,AS A RESULT,LEADS TO AN ALMOST PROPORTIONAL REDUCTION IN POWER CONSUMPTION. VARIABLE SPEED CONTROLS CONSTITUTE THE MOST EFFICIENT METHOD TO CONTROL CAPACITY. MP/I C VSD

73 Ing de Producto AIF Entrenamiento Básico SCREW CONTROL SYSTEMS A COMPARISON VARIABLE SPEED CONTROL

74 Ing de Producto AIF Entrenamiento Básico COMPRESSOR CONTROL - DYNAMIC MACHINES PRESSUREPRESSURE FLOW SURGE LIMIT SURGE CONTROL DEMAND FALLS BELOW SURGE CONTROL DEMAND IS ABOVE SURGE CONTROL 2 SCENARIOS: CONTROL ABOVE SURGE CONTROL CONTROL BELOW SURGE CONTROL

75 Ing de Producto AIF Entrenamiento Básico Inlet guide vanes Energy savings with % capacity control Constant pressure within control range CONTROL SYSTEMS - DYNAMIC MACHINES CONTROL ABOVE SURGE CONTROL Inlet Throttle Valve Inlet Guide Vane

76 Ing de Producto AIF Entrenamiento Básico V1 V2 V1 V2 VELOCITY CHANGE(V) =V1-V2 VELOCITY CHANGE =V1-V2 < V NORMAL INLET GUIDE VANES V2 V1 VELOCITY CHANGE =V1-V2 < V DIFFUSER GUIDE VANES CONTROL SYSTEMS-DYNAMIC MACHINES CONTROL ABOVE SURGE CONTROL * ABOVE EXAMPLE IS FOR AXIAL FLOW MACHINES

77 Adjustable inlet guide vanes provide a pre whirl to the air or gas,smoothly controlling capacity without any turbulence unlike the throttle valve 9%energy savings at part load ZH-series Efficient centrifugal compressors Plant demand Inlet throttle valve at 100% pressure Inlet guide vanes at 100% pressure Energy savings Capacity % Pressure % Power %

78 Ing de Producto AIF Entrenamiento Básico Volume flow Pressure CONTROL SYSTEMS-DYNAMIC MACHINES CONTROL BELOW SURGE LIMIT AUTO DUAL AND MODULATED BLOW-OFF CONTROLS RELOADING TIME IS LONG WITH CONVENTIONAL RADIAL AND THRUST BEARINGS OFTEN CALLING FOR HUGE STORED CAPACITY TO PROTECT PROCESS ENTAILS BLOW-OFF AT PARTIAL LOADS THUS WASTING POWER

79 Ing de Producto AIF Entrenamiento Básico SIMPLE TILTING PAD TILTED PAD BEARING CONFIGURATIONS DYNAMIC MACHINES JOURNALSHAFT DUE TO THE HIGH SPEEDS,DYNAMIC MACHINES EMPLOY SLEEVE BEARINGS,WHICH EMPLOY AN OIL FILM TO SUPPORT THE SHAFT.THIS BEARING SYSTEM INTRODUCES RESTRICTIONS BECAUSE CHANGES IN LOAD PATTERNS CAUSES THINNING OF THE FILM OR FILM DISPERSION.SUDDEN OR FREQUENT CHANGES IN LOAD CONDITIONS HAVE TO BE CONTROLLED.

80 Ing de Producto AIF Entrenamiento Básico THE FLEXIPAD BEARINGS TILTING OR FLEXIPAD BEARINGS WITH THRUST PADS IN BOTH DIRECTIONS PROVIDE GOOD DAMPING CHARACTERISTICS WITH MANY BENEFITS IMPROVED MECHANICAL SAFETY IMPROVED STABILITY WHEN CROSSING CRITICAL SPEEDS BETTER TOLERANCES TO IMPROVE EFFECIENCY FASTER TURN AROUND FOR RELOADING ABILITY TO RUN UNLOADED

81 Ing de Producto AIF Entrenamiento Básico THE RIGHT CHOICE COMPRESSOR TYPES WORKING PRINCIPLES CHARACTERISTICS CONTROL SYSTEMS STAGING GENERAL INFORMATION

82 Ing de Producto AIF Entrenamiento Básico. STAGING OF COMPRESSORS A P-V DIAGRAM REPRESENTATION V P W P V W XXXXXXXXXX SINGLE STAGE2 STAGE X - ENERGY SAVING MULTI-STAGING SAVES ENERGY AND LIMITS OUTLET TEMPERATURES

83 Ing de Producto AIF Entrenamiento Básico P V P V P V EFFICIENT OPERATION AT THE BUILT-IN PRESSURE RATIO (BIPR) A B X X LESS EFFICIENT EITHER ABOVE (A) OR BELOW THE BIPR IF THE BUILT-IN PRESSURE RATIO IS 3 A 1-STAGE MACHINE OPERATES BEST AT A PRESSURE RATIO OF AND A 2-STAGE AT 6-10 STAGING - SCREW MACHINES X-EXCESS ENERGY

84 Ing de Producto AIF Entrenamiento Básico STAGING CRITERIA - TURBO MACHINES SAFETY CONSIDERATIONS THE NO.OF STAGES IS DEDUCED AS FOLLOWS : WITH 14 PH SS USED THE MAX. TIP SPEED IS 450 M/S. WHEN USING 45 DEG.IMPELLERS THIS IS ATTAINED WITH A PR OF 2.1 PER STAGE. HENCE A 2 STAGE MACHINE CAN ACHIEVE A MAX.WORKING PRESSURE OF 2.1 EXP 2 = =3.41 KG/CM2 (G). AND A 3 STAGE MACHINE CAN ACHIEVE A MAX.WORKING PRESSURE OF 2.1 EXP 3 = =8.26 KG/CM2 (G).

85 Ing de Producto AIF Entrenamiento Básico number of stages Efficiency versus number of stages [ bar(e)] mechanical efficiency total efficiency aerodynamic efficiency FACTORS DETERMINING AERODYNAMIC EFFECIENCY ARE SPECIFIC SPEEDS MACH NUMBERS REYNOLDS NUMBERS STAGING CRITERIA - TURBO MACHINES EFFECIENCY CONSIDERATIONS CURVE CORRESPONDS TO 7-8 BAR OPERATION

86 Ing de Producto AIF Entrenamiento Básico STAGING CRITERIA -TURBO MACHINES EFFECIENCY CONSIDERATIONS na 1/2 Specific Speed = rpm x (flow) /4 (Adiabatic Head) Operation above or below the optimum Specific Speed compromises on Aerodynamic Effeciency(n a). Characteristically the optimum is achieved at m/s impeller tip speed with 45 deg. impellers SPECIFIC SPEED

87 Ing de Producto AIF Entrenamiento Básico STAGING CRITERIA-TURBO MACHINES EFFECIENCY CONSIDERATIONS Operation above the Critical Mach Number results in a rapid decrease in the Aerodynamic Effeciency(n a). The speed of sound being 332m/s,the critical Mach No.corresponds to about m/s MACH NO. na Mc = 1.2 Mach No. = Velocity of Flow/ Velocity of Sound

88 Ing de Producto AIF Entrenamiento Básico THE RIGHT CHOICE FOR RECIPROCATING COMPRESSORS THE STAGING RULES (THEORETICALLY) ARE MAINLY DETERMINED BY THE OUTLET TEMPERATURE.THE LIMITING TEMPERATURE IS MUCH LOWER BECAUSE IN THESE MACHINES THERE ARE MANY MOVING PARTS IN FRICTIONAL CONTACT WITH EACH OTHER.HIGH TEMPERATURE CAUSES DRAMATIC INCREASES IN CONSUMPTION OF SPARE PARTS DUE TO LOWERED VISCOSITY AT THE PARTS INTERFACE. DUE TO THIS REASON,THE STANDARD API 618 LIMITS THE OPERATING TEMPERATURE TO 140 DEG.C. IF THIS IS TO BE ACHIEVED,WORKING BACK FROM THE TEMPERATURE EQUATION,THE PRESSURE RATIO PER STAGE BECOMES: P2/P1=( /273+40)EXP (1.4/1.4-1)=2.63 AT AN INLET TEMPERATURE OF 40 DEG C. THEREFORE, IDEALLY A 2 STAGE MACHINE SHOULD DELIVER 4.29 BAR(G)

89 Ing de Producto AIF Entrenamiento Básico THE RIGHT CHOICE COMPRESSOR TYPES WORKING PRINCIPLES CHARACTERISTICS CONTROL SYSTEMS STAGING GENERAL INFORMATION

90 Ing de Producto AIF Entrenamiento Básico TURBO COMPETITOR STRATEGY UNLIKE THE ZH6 COMPETITORS GENERALLY FOLLOW A PREDICTABLE STRATEGY : CAPITAL COSTS ARE KEPT LOW : THEY PROVIDE INCOMPLETE PACKAGES WHICH REQUIRE HEAVY SITE EXPENSES. CUSTOMERS ARE NEVER INFORMED IN ADVANCE. COST BEC 1M PER M/C THEY PROVIDE LOW PROFILE MACHINES AND CHEAP COMPONENTS 2 STAGE MACHINES INSTEAD OF 3 STAGE WITH HIGH SPEEDS LOW VALUE HYDROSTATIC BEARINGS INSTEAD OF HYDRODYNAMIC BEARINGS POOR QUALITY MICROPROCESSORS THROTTLE VALVES INSTEAD OF INLET GUIDE VANES LOW PROFILE CONTROL SYSTEMS COPPER COOLERS INSTEAD OF CU-NI MOTORS WITH HIGH SERVICE FACTORS COST SAVINS OF BEC 1.5 M AT THE COST OF PERFORMANCE

91 Ing de Producto AIF Entrenamiento Básico TURBO COMPETITOR STRATEGY STAINLESS STEEL INTAKE PIPING BEC 45,000 INTERCONNECTING AND INST. AIR PIPING AND VALVES BEC 80,000 MICRO INTAKE FILTER (2U) BEC 65,000 ISOLATED FOUNDATIONS (WITH CORK INLAY) BEC 350,000 INSTRUMENT AIR COMPRESSOR WITH DRYER BEC 75,000 EXPANSION JOINTS BEC 30,000 SILENCING CANOPY (OPTIONAL) BEC 140,000 OTHER ITEMS (WATER MANIFOLD,ETC)BEC 100,000 TOTAL INSTALLATION COST BEC 885,000 TOTAL INSTALLATION TIME 30 DAYS

92 ZH-series Efficient centrifugal compressors Complete and ready to use easy, low cost installation no special foundation no anchor bolts minimal floor space NO MANUFACTURER EXCEPT ATLAS COPCO PROVIDES READY TO RUN TURBO MACHINES

93 Ing de Producto AIF Entrenamiento Básico RADIAL MACHINES API 617 VS API 672 FLEXIBLE SHAFT API 617 RIGID SHAFT API 672 BEARINGS DUE TO DISPLACEMENT OF THE ENDS IN THE FLEXIBLE SHAFT DESIGNS,A GENEROUS CLEARANCE IS TO BE MAINTAINED BETWEEN THE IMPELLER AND THE SHROUD,FOR SAFETY REASONS,CAUSING COMPROMISES ON VOLUMETRIC EFFECIENCY. RIGID SHAFT DESIGNS CAN MAINTAIN MUCH CLOSER TOLERANCES AS IN API 617 TURBOS OR IN SCREW COMPRESSORS

94 Ing de Producto AIF Entrenamiento Básico

95 TURBO COMPETITOR STRATEGY THEY UNDERSTATE RUNNING COSTS : CAPACITIES ARE STATED IN INTAKE VOLUME WHICH IS OFTEN MUCH LOWER THAN FAD DUE TO SYSTEM LOSSES POWER IS ALWAYS SPECIFIED AT HIGHEST TEMPERATURES TO SHOW LOW POWER. FOR INSTANCE AT 20 DEG C POWER IS 8.5%HIGHER THAN AT 40 DEG C SPARE PART CONSUMPTION IS HIDDEN ALTHOUGH THIS IS GENERALLY HIGHER THAN SCREW. GUARANTEES ARE ALWAYS VAGUE. HIGH SPEEDS AT TIMES RESULT IN IMPELLER RUBS,BLADE RESONANCE, EROSION AND SALT DEPOSITIONS

96 Ing de Producto AIF Entrenamiento Básico TURBO COMPETITOR STRATEGY RUNNING AND MAINTENANCE : SOME FACTS TO CONSIDER : UNLIKE THE ZH6 ALL IMPELLERS ARE CUSTOM MADE.HENCE NO STOCK CAN BE KEPT. - IMPELLER FAILURE MEANS THIS HAS TO BE MANUFACTURED. IMPELLERS NEED TO BE PERIODICALLY CLEANED AND BALANCED. FEW HIGH SPEED BALANCING MACHINES ARE AVAILABLE. OVERHAULS NEED TO BE DONE AT SITE MEANING PRODUCTION LOSS OR HIGH STANDBY CAPACITY AFTER A POWER FAILURE,MACHINE SHOULD BE PRELUBRICATED BEFORE START- UP. LOADING UNLOADING CYCLES SHOULD BE LIMITED TO 1 IN 180 SECONDS. PRESSURE DROPS IN FILTERS OR COOLERS CAN CAUSE SURGE IN THE MARGINAL DESIGNS OF COMPETITION

97 Ing de Producto AIF Entrenamiento Básico WE HAVE NO OPINION ! EACH COMPRESSOR TYPE HAS ITS OWN CHARACTERISTICS AND IS BEST SUITED TO A PARTICULAR APPLICATION.IT IS OUR RESPONSIBILITY TO LOOK INTO THE APPLICATION AND SUGGEST THE TECHNOLOGY WHICH SUITS HIM BEST. WE HAVE THEM ALL THE BEST COMPRESSOR FOR A SPECIFIC APPLICATION


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