Basics vacuum noun 1 a space entirely devoid of matter 2 an enclosed space from which matter especially air has been partially removed so that the matter or gas remaining in the space exerts less pressure than the atmosphere opposed to ID: 436800
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Slide1
Vacuum PumpsSlide2
Basics
vac·u·um
noun 1. a space entirely devoid of matter. 2. an enclosed space from which matter, especially air, has been partially removed so that the matter or gas remaining in the space exerts less pressure than the atmosphere ( opposed to
plenum
).
(dictionary.com)
Exhaust pressure=
atm
generally
Base pressure = pressure pump gets down to
Compression ratio = exhaust/base= big number
Boyles Law P
1
V
1
=P
2
V
2Slide3
History of vacuum pumps
Suction pumps go way back (Romans, Byzantine empire, etc)
Major improvements on the idea of vacuum made by Galileo, Evangeilist Torricelli, and Blaise PascalOtto von Guericke made first pump and famous for Magdeburg hemispheres experimentSlide4
Types of Vacuum pumps
Positive displacement pumps
Expand a cavity, seal, exhaust, repeatMomentum transfer pumps (molecular pumps)High speed liquids or blades to knock gasses aroundEntrapmentCreate solids or adsorbed gases (cryopumps
)Slide5
Roughing pumps
Pumps from
atm pressure down to rough vacuum (0.1 Pa, 1X10-3
torr
)
Necessary because turbo pumps have trouble starting from atmospheric pressure
Usually Rotary Vane pumps
Can have oil or notSlide6
Rotary vane pumps
Oil Sealed Rotary
Pumps
Understanding Gas
Ballast
www2.avs.org/chapters/nccavs/pdf/Gas_
Ballast
_OilSealed
Pumps
.pdfSlide7
Rotary vane pumps
Works by increasing the gas/vapor ratio (air is mostly gas)
As you might imagine this interferes with the final vacuum
Condensation of vapor in the gas mixture is a problem with these pumps. Solution
BallastingSlide8
Types
One stage or two stage
Belt Drive or direct drive
Slower 400-600 RPM
Bigger, Cheaper
Faster 1500 to 1725 RPM
Smaller, lighterSlide9
Turbo (molecular) pumps
Gas molecules interact with spinning blades and are preferentially forced
downwardHigh vacuum (10-6 Pa) requires rotation of 20,000 to 90,000 revolutions per minuteGenerally work between 10-3 and 10-7
Torr
Ineffective before gas is in “molecular flow”Slide10
Options:
Bearings: Ceramic (oil lubricated) Magnetic (supported w/out physical contact), also hybridRotor options (Blade configuration)Cooling (air or water)
Turbo (molecular) pumpsSlide11
Pump Care
Rough pumps
shouldn’t need a lot of maintenance
If they do repair kits are available:
Minor kit
includes all necessary seals (shaft seals, valves, o-rings, etc
)
Major kit
includes Minor Kit components plus vanes, springs, plugs, etc
.
Seem to be available for most major brands and types
Turbopumps
should need even less maintenance, bearings can wear out but must be replaced by manufacturer for balancing.
http://www.sisweb.com/vacuum/sis/iseries-maintkit.htmSlide12
Pump specs
Displacement
50Hz
3.7 m
3
h
-1
/ 2.2 ft
3
min
-1
60Hz
4.5 m
3
h
-1
/ 2.6 ft
3
min
-1
Speed (Pneurop 6602)
50Hz
3.3 m
3
h
-1
/ 2 ft
3
min
-1
60Hz
3.9 m
3
h
-1
/ 2.3 ft
3
min
-1
Ultimate pressure (high vac mode)
2.0 x 10
-3
mbar / 1.5 x 10-3 TorrUltimate pressure GB I (high vac mode)3.0 x 10-2 mbar / 2.3 x 10-2 TorrUltimate pressure GB II (High throughput mode)1.2 x 10-1 mbar / 9.1 x 10-2 TorrMax inlet pressure for water vapour80 mbar / 60 TorrMax water vapour pumping rate – GB I60 g/hMax water vapour pumping rate – GB II220 g/hMax allowed outlet pressure1 bar gauge / 14 psigMax allowed inlet and gas ballast pressure0.5 bar gauge / 7 psigMotor power 50/60Hz450 / 550WNominal rotation speed 50/60Hz1500 / 1800rpmWeight (without oil)25 kg / 55 lbOil capacity min/max0.42/0.7 litresRecommended oilUltragrade 19Inlet flangeNW25Exhaust flangeNW25Noise level 48 dBA @ 50 HzOperating temperature range12 – 40 °C
Spec sheet for an
Edwards A65209903
RV rotary vane pump
$3171Slide13
Pumping Speed
N
2
ISO63/63CF (DN40NW)(ISO100)
61
ls
-1
(42
ls
-1
) (66
ls
-1
)
He ISO63/63CF (DN40NW)(ISO100)
57 ls
-1
(49 ls
-1
) (59 ls
-1
)
H
2
ISO63/63CF (DN40NW)(ISO100)
53 ls
-1
(48 ls
-1
) (54 ls
-1
)
Compression ratio
N
2
>1 × 10
11
He
1 x 10
6
H
2
5 x 104Ultimate Pressure (mbar)With RV backing pump ISO/CF<5 x 10-9 / 5 x 10-10With diaphragm backing pump ISO/CF<5 x 10-8 / 5 x 10-9Outlet flangeDN16NWRecommended backing pump*RV5/XDS5Vent port1/8 inch BSPPurge port1/8 inch BSPMax continuous inlet pressure (light gas pumping)†Water cooling (water at 15 °C, ambient temp at 40 °C)2 × 10-2 mbarForced air cooled, 35 °C ambient1 × 10-2 mbarPump rotational speedNominal rotational speed
90000 rpm
Standby rotational speedVariable from 49500 to 90000 rpm (63000 rpm default)Programmable power limit settingsVariable from 50-120W (80W default)Start time to 90% speed110 s ‡Analogue outputsRotational speed;Power consumption; Pump temp; Controller tempCooling method?Forced air / waterAmbient air temperature for forced air cooling5 - 35 °CMin cooling water flow rate (water 15 °C)15 l h-1Water temp range10 - 20 °CMax inlet flange temp100 °C
Subset of specs for Edwards EXT 556H
turbomolecular
pumpSlide14
Pump Speed
Pressure
Rotary Vane:
Pump speed lower at low vacuum
Turbo pumps:
oppositeSlide15
Useful fitting terminology
Flanges
Standard quick Release (QF, KF, NW, or DN)Named based on internal diameter DN16KF is 16mm (16-50mm)Large Quick releases (LF, LFB, MF or ISO)Clamps or bolts (63-500mm)Conflat
(CF) used in ultra high vacuum settings, usually metal to metal seals
Sizing odd: Europe inner
diamter
in mm, NA outer diameter in inchesSlide16
Sizes we will likely find.
www.vacuumresearchcorp.com/pdfs/valves/
nwflanges
06.pdfSlide17
Pumps on the Delta S
Pumping system for AnalyzerTurbo molecular pump TPH 050Vacuum pump E2 M1, 5
2Differential Pumping systemTurbo molecular pump TPH 050Turbo molecular pump TPH 240
Vorvakuumpumpe
E2 M5, 50160 HzSlide18
Turbo molecular pump TPH 050
Turbo molecular pump TPH 240Slide19
Units of pressure for your notes
Pascal
(Pa)
Bar
(bar)
Technical atmosphere
(at)
Atmosphere
(atm)
Torr
(Torr)
Pound-force per
square inch
(psi)
1 Pa
≡ 1
N
/m
2
10
−5
1.0197×10
−5
9.8692×10
−6
7.5006×10
−3
145.04×10
−6
1 bar
10
5
≡ 10
6
dyn
/cm
2
1.0197
0.98692
750.06
14.5037744
1 at0.980665 ×1050.980665≡ 1 kgf/cm20.96784735.5614.2231 atm1.01325 ×1051.013251.0332≡ 1 atm76014.6961 Torr133.3221.3332×10−31.3595×10−31.3158×10−3≡ 1 Torr; ≈ 1 mmHg
19.337×10
−31 psi6.895×10368.948×10−370.307×10−368.046×10−351.715≡ 1 lbf/in2