TMMS04 Mechatronics (HT2013) 09 Pneumatics Introduction to Pneumatics Magnus Sethson 1 1
Pneumatic Example Applications 2
Pneumatics Moving things with air 3 3
Popular Pneumatic Systems Hesa Fredrik 4 4
Some History 5 5
The Pneumatic Tunnel under Broadway, NY 6 6
Vehicle Pneumatic Systems 7 7
Air for Drilling 8 8
Pneumatics in Health Care 9 9
Source: Pneumatic Hand Tools 10 10
Compressed Gas, Production, Distribution and Consumers 11 11
Rodless Pneumatic Cylinder (FESTO) Blue Pipe connectors Pneumatic Valve Systems (SMC) Pneumatic Treatment System (Rexroth) The modular Worlds of Pneumatic Components 12 12
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Thermal Processes (Quasi-Equilibrium Processes) 15 15
Thermal Processes p V n = C n = 0 : isobaric n = 1 : isothermal n = 1 : isochoric n = : adiabatic Brownian Motion 16 16
Compressors 17 17
Compressor 18 18
Multi-Stage Compressor 19 19
Screw Compressor 20 20
Thermal System Efficiency η e/c = W t,full-pres expan / W t,isentropic comp T 3 = T 1 n = 1,01 (isothermal compression) n = 1,4 n = 1,25 21 21
Total System Efficiency El-motor efficiency: η em = 0,92, Mechanical system efficiency: η m,s = 0,80, Volumetric eff. single-stage piston comp: η v,c 22 22
Distribution 23 23
Blue Tubing <10bar 24 24
Air Treatment System Oil-free Dry Right temperature No particles Gas monitoring 25 25
Actuators 26 26
Cylinders 27 27
Motors 28 28
Pneumatic Muscle Pneumatic Muscle 29 29
Saefty 30 30
Certification (Sweden) Akrediterat Kontrolorgan Akrediterat Kontrolorgan Akrediterat Kontrolorgan Tryckkärlsdirektivet: PED, 97/23/EC (AFS 1999:4) Tillverkare av tryckbärande anordningar Enkla tryckkärl: AFS 1994:53 (SPVD, 2009/105/EC) Tillverkare av enklare trykbehållare Användning: AFS 2002:1 Brukarens krav på tillsyn och underhåll Rörledningar: AFS 2005:2 Tillverkare av rörledningar Besiktning: AFS 2005:3 Besiktning av trycksatta anordningar 31 31
Orifice & Volumes 32 32
Gas Volumes Pressure Vessels (Energy storage) Cylinders (Linear motion) Dampers (Motion retardation) Accumulators (Pressure ripple cancelation) Emergency Energy Storage (Long term readiness) 33 33
No volumes without orifices! P 1 const m 1 const T 1 const P 2 const Example of pneumatics system with many orifices. US Patent 6709068 34 34
Industrial Pneumatic Valves CETOP Standard Examples: Ref: Bosch Rexroth AG, 5/2 Valve, Series HF02 Ref: SMC Inc. 2/2 Valve, Series VCA 35 35
Orifice Assumptions Mass balance: ṁ = A 1 w 1 1 = A 2 w 2 2 Energy balance: Z 2 1 Vdp= mw 2 2 2 mw 1 2 2 w 1 0 Adiabatic: p 1 v 1 = p 2 v 2 v = V m Ideal Gas: p 1 v 1 = RT 1 P 1 const m 1 const T 1 const P2 const Ref: Peter Beater, Pneumatic Drives, System Design, Modelling and Control, Springer Verlag, 2007 36 36
Subsonic Orifice Flow Function 0.5 ṁ p 1 p 2 0.4 0.3 Ψ 0.2 Max at (0.528,0.484) ṁ = A p2 p 1 p2 = p 1 v u t p 1 r 2 RT 1 1 " p2 p 1 2 p2 p 1 0.1 +1 # 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 p 2 /p 1 Wantzel & St. Venant, 1839 37 37
Critical Orifice Flow Function 0.5 ṁ p 1 p 2 0.4 0.3 ṁ = A p2 p 1 = p2 p 1 8s >< >: r 2 p 1 RT 1 apple 2 p2 1 p 1 p2 p 1 +1 Chocked Flow for p 2 p 1 > 0.528 1 q 1 2 +1 +1 for p 2 p 1 apple 0.528 Ψ 0.2 0.1 Subsonic Flow 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 p 2 /p 1 Perry, 1949 38 38
Approximative Orifice Flow ṁ p 1 p 2 ṁ = p 1 C 0 r T0 T 1 Sanville, 1971 8s >< 1 >: p2 p 1 1 b b 2 for p 2 p 1 >b 1 for p 2 p 1 apple b ISO 6358 www.iso.org, 1989 Reference conditions: Temperature,T 0 = 293.15K Pressure,p 0 = 100kPa Gas constant,r 0 = 288J/(kg K ) Relative humidity = 65% Density, 0 =1.185kg/m 3 Approximation motives: + Non-rounded edge orifice + Unknown inlet velocity conditions + Standardized parameter description + Generality 39 39
Pneumatic Valves Characterized by: b, C, Q n Examples: MO - rate value time time C 24 V 368 1400 13 40 0820056051 24 V 368 1400 13 0820056501 24 V 368 1400 19 30 0820056001 Model VCA (for air) 2 port solenoid valve Class Port size 2 3 4 1/4 (8A) 1/4 ( 8A) 3/8 (10A) 3/8 (10A) 1/2 (15A) 3/4 (20A) Orifice size (mmø) 3 5 4 7 5 7 10 Max. operating pressure differential(mpa) 1.0 0.15 1.0 0.15 1.0 0.3 0.15 Note 1) Weight values are for the grommet type. Flow characteristics C [dm 3 /(s< bar)] b Cv 1.1 2.9 1.9 5.0 3.0 5.4 7.7 0.45 0.21 0.24 0.16 0.35 0.27 0.23 0.29 0.68 0.45 1.2 0.78 1.4 1.9 Max.operating pressure (MPa) 1.0 1.0 1.0 (1) Weight (kg) 0.21 0.30 0.50 Ref: Bosch Rexroth AG, 5/2 Valve, Series HF02 Ref: SMC Inc. 2/2 Valve, Series VCA 40 40
The Valve & The Volume p 1,T 1 p 3,T 3 V,p v,t v A 12,b 12,C 12 A 23,b 23,C 23 41 41
The Volume First Law of Thermodynamics: Internal Energy: du = Q p V U = mc v T T 1 = T 2 = T 3 = T a V =0 Mass Transport: ṁ = ṁ in ṁ out Energy Transport (Enthalpy): dh = ṁ in c p T in ṁ out c p T out Ideal Gas: pv = mrt p 1,T 1 p 3,T 3 V,p v,t v A 12,b 12,C 12 A 23,b 23,C 23 Ref: Peter Beater, Pneumatic Drives, System Design, Modelling and Control, Springer Verlag, 2007 42 42
Timing Adjustment ṁ p 1 p 2 ṁ = p 1 C 0 r T0 T 1 Sanvill 8s >< 1 >: p2 p 1 1 b b 2 for p 2 p 1 >b 1 for p 2 p 1 apple b Ψ 0.5 0.4 0.3 0.2 0.1 Chocked Flow Subsonic Flow 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 p 2 /p 1 43 43
Industrial Valves 44 44
Fyllning av volym Tömning av volym Diagrammen nedan visar p v som funktion av dimensionslös tid τ = A 23 A 12 som parameter. RT A12 t med areaförhållandet V Diagrammen nedan visar p v som funktion av dimensionslös tid τ = A 12 A 23 som parameter. RT A23 t med areaförhållandet V 0,6 A 23 /A 12 = 0,0 0,6 A 12 p 1 T 1 p v A 23 p V 3 T v (a) Nedströmstrycket p 3 =0,1 MPaabsolut. T 3 Tryck pv [MPA absolut] 0,5 0,4 0,3 0,2 0,1 0,5 1,0 1,5 2,0 A 12 p 1 T 1 p v A 23 p V 3 T v (a) Nedströmstrycket p 3 =0,1 MPaabsolut. T 3 Tryck pv [MPA absolut] 0,5 0,4 0,3 0,2 0,1 A 12 /A 23 = 1,0 0,8 0,6 0,4 0,2 0,0 0,0 0,0 0,5 1,0 1,5 tao [-] 2,0 2,5 0,0 0,0 1,0 2,0 3,0 tao [-] 4,0 5,0 (b) Uppströmstrycket p 1 =0,6 MPa(absolut) (b) Uppströmstrycket p 1 =0,6 MPa(absolut) Tryck pv [MPA absolut] 1,1 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 A 23 /A 12 = 0,0 0,5 1,0 1,5 2,0 Tryck pv [MPA absolut] 2,2 2,0 1,8 1,6 1,4 1,2 1,0 0,8 0,6 A 23 /A 12 = 0,0 0,5 1,0 1,5 2,0 Tryck pv [MPA absolut] 1,1 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 A 12 /A 23 = 1,0 0,8 0,6 0,4 0,2 Tryck pv [MPA absolut] 2,2 2,0 1,8 1,6 1,4 1,2 1,0 0,8 0,6 A 12 /A 23 = 1,0 0,8 0,6 0,4 0,2 0,2 0,1 0,4 0,2 0,2 0,1 0,0 0,4 0,2 0,0 0,0 0,0 0,5 1,0 1,5 tao [-] 2,0 2,5 0,0 0,0 0,5 1,0 1,5 tao [-] 2,0 2,5 0,0 0,0 1,0 2,0 3,0 tao [-] 4,0 5,0 0,0 0,0 1,0 2,0 3,0 tao [-] 4,0 5,0 (c) Uppströmstrycket p 1 =1,1 MPa(absolut) (d) Uppströmstrycket p 1 =2,1 MPa(absolut) (c) Uppströmstrycket p 1 =1,1 MPa(absolut) (d) Uppströmstrycket p 1 =2,1 MPa(absolut) Ref: FluMeS Formelsamling 45
CETOP 46 46
Drawing Symbols Standard Examples 47 47
Diagram Example 48 48
Example 49 49
Diagram Example 50 50
Selecting Cylinder & Valve (Example) 51 51
Products The Bosch/Rexroth Homepage 52 52
Pneumatic Power Ideal gas: p V Normal -effekt: m R T V q N = normalflöde, [m 3 /s] (NTP) p 0 = 1,0 bar och 0 = 1,23 kg/m 3 0 m Gaskonst. R = 287 J/(kg K) P N m1 R T 1 q 1 p1 Konstant temperatur, T 1 = T 0 = 293 K, ger effekten: 1 p m 1 1 m1 R T1 1 P N q N p 0 0 53 53
Pneumatic Cylinder Cushioning C 1, b 1 1 Cyl. A 0 A 1 A 2 Cyl. A a 0 p 1 p 2 v + ) ( ) ( ) ( C 2, b 2 Väg/Tid-diagram v - C 3, b 3 a 1 Antag att de ventilstrypningar som genomströmmas av cylinderns returflöde (utloppsstrypningar) bestämmer max kolvhastighet för båda rörelseriktningarna. Antag att strypningarnas konduktanser är lika: C 1 = C 2 = C 3 = C Vid plus-slaget finns två seriekopplade utloppsstrypningar med konduktanserna C 2 = C 3 = C, vilket ger v max C p A 23 2 a C p a 1/3 2 A2 För minus-slaget gäller en utloppsstrypning med konduktanserna C 1 = C, vilket ger v max C1 p A 1 a C p A 1 a v max v max 54 54
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Select from Series 589 5/2 Valve 56 56
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Magnus Sethson 58 58