basic of thermo & reciprocating compressor
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Thermodynamics Thermodynamics
Thermodynamics is the study ofthe eects of work, heat, andenergy on a system.
Thermodynamics is onlyconcerned with macroscopic(large-scale)µscopic
changes and observations
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The aws of Thermodynamics! The aws of Thermodynamics!
"ummary"ummary#eroth aw If two systems are each in thermal equilibrium
with a third, they are also in thermalequilibrium with each other.
%irst aw The increase in internal energy of a closedsystem is equal to the dierence of the heatsupplied to the system and the work done byit: ΔU ! " #
"econd aw $eat cannot spontaneously %ow from a
colder location to a hotter location. Third aw
The entropy of all systems and of all states ofa system is smallest at absolute ero 3
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Thermodynamic "ystems Thermodynamic "ystems
5
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Thermodynamic 'rocesses Thermodynamic 'rocesses Isobaric process : the pressure is constant.
Isochoric process : the volume is constant.
Isothermal process :the temperature is constant.
Adiabatic process : no heat enters or leaves the
system; i.e. Q = 0.
Isentropic process : the entropy is constant. It is also
known as reversible adiabatic process.
Isenthalpic rocess: occurs at a constant !nthalpy
"
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The deal as aw The deal as aw Ideal gas law ! '* + mT or 'v + T,
where m is the no. of kmoles, v is the volume per kmole, T is the absolutetemperature in , and the gas constant + ./01 2 033 45(.kmol).
%or a constant 6uantity of gas, '1*15T1 + '2*25T2.
Avogadro's law ! %or a given mass of an ideal gas, the volume andamount (moles n) of the gas are directly proportional if the temperature and pressure are constant. * is proportional to moles n
v/n=k
##
##
T increasingT increasing
$$ $$
V increasingV increasing
P increasingP increasing
http://en.wikipedia.org/wiki/Ideal_gashttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Ideal_gas
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The energy balance for a The energy balance for a
steady-7ow device (nole,steady-7ow device (nole,
compressor, turbine and pump)compressor, turbine and pump)
with one inlet and one e2it is!with one inlet and one e2it is!
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%luid 8oving 96uipment%luid 8oving 96uipment
%luids are moved throu&h 'low systems usin& compressors,
pumps, 'ans and blowers. (uch devices increase the mechanical
ener&y o' the 'luid. $he additional ener&y can be used to increase
) #elocity *'low rate+) ressure) !levation
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:;":;"
COMPONENT Intake Air Filters : Preven d!" and a#$"p%eri& i#p!riie" 'r$# enering
&$#pre""$r. D!" &a!"e" "i&ing vave"* "&$red &yinder"* e+&e""ive ,eare&.
Compressor : 'ressuries the air
Inter-stage Coolers : Red!&e %e e#pera!re $' %e air (ga") -e'$re iener" %e ne+ "age $ red!&e %e ,$r $' &$#pre""i$n and in&rea"ee''i&ien&y. T%ey &an -e ,aer$r air&$$ed.
After Coolers : Red!&e %e e#pera!re $' %e di"&%arge air* and %ere-yred!&e %e #$i"!re &arrying &apa&iy $' air.
Air-drers : Air dryer" are !"ed $ re#$ve #$i"!re* a" air '$r in"r!#enand pne!#ai& e/!ip#en need" $ -e reaivey 'ree $' any #$i"!re. T%e
#$i"!re i" re#$ved -y "!ing ad"$r-en" $r re'rigeran dryer"* $r "ae $'%e ar %eae"" dryer".
Moist!re Traps : Air rap" are !"ed '$r re#$va $' #$i"!re in %e&$#pre""ed air di"ri-!i$n ine". T%ey re"e#-e "ea# rap" ,%erein %eair i" rapped and #$i"!re i" re#$ved.
"ecei#ers : Depending $n %e "y"e# re/!ire#en"* $ne $r #$re airre&eiver" are generay pr$vided $ red!&e $!p! p!"ai$n" and pre""!revariai$n".
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:
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Types of compressor
Type of
compressor
Positive
displacementDynamic
Reciprocating Rotary Centrifugal !ial
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:ompressor:ompressor selectionselection
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:apacity of compressor:apacity of compressor
:apacity of :ompressor basicallyindicated by following twoparameter
0.'ressure?.%;@
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#hat is &'("#hat is &'(" )apacity of a)apacity of a
)ompressor*)ompressor* The %;@ is the volume of air drawn
into a compressor from theatmosphere. ;fter compression and
cooling the air is returned to theoriginal temperature but it is at highpressure
"uppose atmospheric condition are
'a Ta and *a(the %;@) and thecompressed condition are p , * and T
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"ome deAnations"ome deAnations
Bore + :ylinder diameter. "troke + @istance through which the piston moves. The two e2treme positions of the piston are known as
head-end and crank-end dead centers. :learance *olume (:l) ! *olume occupied by the 7uid
when the piston is at head-end dead centre. 'iston @isplacement ('@) ! *olume, a piston sweeps
through. :ompression atio (rv) ! atio of cylinder volume with
the piston at crank-end dead centre to the cylinder
volume with the piston at head-end dead centre. 8echanical 9Cciency ! which gives an
indication of the
losses occurring between the piston and driving shaft.
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)ompressor )ompressor +ciency+ciency
(e-nitions(e-nitions
Isothermal Efficiency
Isothermal Efficiency =
Actual measured input power
IsothermalPower
Isothermal power(kW) = P1 x Q1 x loer!"#$%
P1 = A&solute intake pressure k! cm'
Q1 = ree air deliered m"!hr$r = Pressure ratio P'!P1
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)ompressor )ompressor +ciency+ciency
(e-nitions(e-nitions
Volumetric Efficiency
"(ree air deli)ered m !min
*olumetric efficiency =+ompressor displacement
+ompressor ,isplacement = Π x ,' x - x . x χ x n
/
, = +ylinder &ore0 metre
- = +ylinder stroke0 metre
. = +ompressor speed rpmχ = 1 for sinle actin and
' for dou&le actin cylinders
n = o$ of cylinders
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eciprocatingeciprocating
:ompressors:ompressors Types
0. "ingle acting
The working 7uid compressed at
only one side of the piston
?. @ouble acting
The working 7uid compressed
alternately on both sides of thepiston.
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rame !"2# $ 1%&"Prame !"2# $ 1%&"P0%rame
;ssly.
?nner Dead
;ssly. (')/:ylinder
;ssly. (')
1
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rame Cross Sl(de Crank s)a*+ andrame Cross Sl(de Crank s)a*+ and
Conne,+(ng rod assem-l.Conne,+(ng rod assem-l. 0. Breather
??.:rosshead
?/. :rossDead Hut
/E.:onnecting od
13.Big 9ndBearing
/F.:onnecting rod Bolt
?,?I.
"tud,Hut
+) +) ; t l t l; t l t l
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rea+)er:rea+)er: ; vent or valve to release; vent or valve to release
pressurepressure
or to allow air to move freely aroundor to allow air to move freely around
something.something.Cross)ead! s a mechanism used in large
and reciprocating compressors to eliminate
sideways pressure on the piston.
Conne,+(ng Rod: connects the piston to the crank or crankshaft. Together with the
crank, they form a simple mechanism that
converts reciprocating motion into rotatingmotion.
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:rank :ase:rank :ase1?. Belt wheel
0/.
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O(l Seal R(ngO(l Seal R(ng !t prevent the oil the!t prevent the oil the
oil to 7ow furtheroil to 7ow further
0aske+! is a mechanical seal which Alls the space between
two or more mating surfaces, generally to prevent
leakage from or into the Joined obJects while under
compression.
C(r,l(p! t is a type of fastener or retaining ring
consisting of a semi7e2ible metal ring with open ends
which can be snapped into place, into a machined groove on a
dowel pin or other part to permit rotation but to
prevent lateral movement. There are two basic types! nternal and e2ternal, referring to whether they
are Atted into a bore or over a shaft.
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Cross !ead P(n : t connects the piston tothe connecting rod and provides abearing for the connecting rod to pivot
upon as the piston moves.
#)rs+ was)er: Thrust washers are long-wearing 7at bearings in the shape of awasher that transmit and resolve a2ial
forces in rotating mechanisms to keepcomponents aligned along a shaft.
Crank P(n/0dgeon P(n: :onnects the
piston to the connecting rod and provides abearing for the connecting rod to pivotupon as the piston moves
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'iston 'arts'iston 'arts
0.'iston;ssembly
?.idering
/.'istoning
1."leeveforpiston
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'iston'iston ing! 'iston rings,ing! 'iston rings,mounted on the pistons ofmounted on the pistons of
lubricated or non-lube (oil free)lubricated or non-lube (oil free)
compressors, are designed tocompressors, are designed to
ensure that the gas isensure that the gas iscompressed and to provide acompressed and to provide a
seal between the piston and theseal between the piston and the
cylinder.cylinder.
ider ing!The functionof rider rings, usedmainly in oil free ormini-lube compressors,
is to support or guidethe piston and rodassembly and preventcontact between thepiston and the cylinder
(risk of seiure).
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"e6uence of operation"e6uence of operation
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deal indicator diagramdeal indicator diagram
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The total work interaction The total work interaction
per cycle !per cycle !
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C)(,ago Pnema+(,: or over a ,en+r.C)(,ago Pnema+(,: or over a ,en+r.
C)(,ago Pnema+(, )as represen+edC)(,ago Pnema+(, )as represen+ed
+og) +ools des(gned +o make +og) o-s+og) +ools des(gned +o make +og) o-s
eas(ereas(er=ay back in 1445 4ohn =. @untley realied that constructionworkers in particular had a need for many tools that werenKtyet available. De founded :hicago 'neumatic Tool :ompanyand set out on a lifelong mission to provide all types ofindustries and companies the tools necessary for theirsuccess.
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"#$% seals an a&reement to manu'acture the &en' diesel engine ,
used in various racin& cars in !urope at the time.
"#()s hica&o neumatic construction and minin& e-uipment is used in
the buildin& o' the
incoln $unnel, /ew ork
$riborou&h 1rid&e, /ew ork
hica&o subway system
1oulder 2am, ri4ona
rand oulee 2am, 6ashin&ton!i&ht dams comprisin& the $ennessee #alley uthority 'lood control and
power &eneration pro7ect
olden ate suspension brid&e, (an %rancisco
"#*)s In response to war e''ort demands, develops the +hot
dimpling machine,- a device that heats rivets to 8,000 de&rees
%ahrenheit"#.)s hica&o neumatic customi4es tools 'or the production o' new
aircra't desi&ns: the &oeing /(/ and /*/,
"#0/ tlas Copco ac1uires Chicago Pneumatic Tool Company
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:hicago 'neumatic:hicago 'neumatic
:ompetition:ompetition9lgi 96uipmentngersoll rand
evathi :p
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@eAnition@eAnition
;n apparatus or machine for raising, driving, e2hausting 7uid, by means of a piston, plunger, orset of rotating vanes
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rinciple o' operation
entri'u&al 'orce*throwin&+
ositive displacement
*physically pushin&+
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Type of PumpsType of Pumps
Classified by operating principlePump Classification
,ynamicPositie
,isplacement
+entrifual .pecial effect 2otary 2eciprocatin
Internal
ear
External
ear -o&e
.lide
ane
3thers (e$$Impulse0 4uoyancy)
Pumps
,ynamicPositie
,isplacement
+entrifual .pecial effect 2otary 2eciprocatin
Internal
ear
External
ear -o&e
.lide
ane
3thers (e$$Impulse0 4uoyancy)
Pumps
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:entrifugal 'umps:entrifugal 'umps9ost common type o' pumpin& machinery. $here are many types, si4es, and
desi&ns 'rom various manu'acturers who also publish operatin& characteristics o'each pump in the 'orm o' per'ormance *pump+ curves. $he device pictured on the
cover pa&e is a centri'u&al pump.
ump curves describe head delivered, pump e''iciency, and net positive suction
head */(+ 'or a properly operatin& speci'ic model pump.
entri'u&al pumps are &enerally used where hi&h 'low rates and moderate head
increases are re-uired.
Terms to be familiarTerms to be familiar
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Terms to be familiar Terms to be familiar
withwith
mpeller-
transmit
energy topressure
*olute- water
passes andpressure is
increased
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#)(s ma,)(ne ,ons(s+s o* an
IMPELLER ro+a+(ng w(+)(n a ,ase 8d(9ser
;(
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=orking principles=orking principles
centrifugal pumpscentrifugal pumps
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!ead (s a +erm *or e>press(ng *ee+ o* wa+er,olmn
!ead ,an also -e ,onver+ed +o pressre
LDeadLLDeadL
"))
feet*(2( P3I
"eser#oirof Fl!id
Press!re
$a!ge
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DeadDead
Dead and pressure areinterchangeable terms providedthat they are e2pressed in their
correct units. The conversion of all pressure
terms into units of e6uivalent
head simpliAes most pumpcalculations.
: i
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:onversion %actors Between:onversion %actors Between
Dead and 'ressureDead and 'ressure!ead 8*ee+ o* l(
231 / Sp 0r
Pressre (n PSI = !ead 8(n *ee+ > Sp0r / 231
PSI (s Ponds per S
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Diameter of
the Impeller
Thickness
of the impeller
:entrifugal mpellers:entrifugal mpellers
Thicker the mpeller- 8ore =ater
arger the @;89T9 - 8ore 'ressure
ncrease the "peed - 8ore =ater and
'ressure
Impeller
%anes
+4ye of theImpeller-
5ater
4ntrance
Two-"tage :entrifugalTwo-"tage :entrifugal
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Two "tage :entrifugal Two "tage :entrifugal'umps'umps
Two mpellerswithin a singlehousing
◦ ;llow deliveryin*olume(parallel) or 'ressure
(series)
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$hrust balance in a multista&e pump
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'ositive @isplacement'ositive @isplacement
'umps'umps$o move 'luids positive displacement pumps admit a 'i
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Reciprocating Pumps
) Piston typeVertical6 Hori'ontal 6 double acting
) Plunger type
) Diaphragm pump
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2iaphra&m pumps
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2iaphra&m pumps
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2iaphra&m eciprocatin& pumps
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p & p & p p
1asic principle is similar to a reciprocatin& plun&er pump>lun&er pressuri4es the hydraulic oil which when pressuri4ed pushes the
diaphra&m and dischar&e starts.
(troke len&th can be ad7usted and hence the dosin& 'low rate.
/o direct contact o' plun&er with the solution.
2irect contact is only with diaphra&m * neoprene, $e'lon etc+
7igure "8 The air valve directs
i d i t th b k id f
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2 i a
p h r a & m =
e c i p r o c a t i n & p u m p s
pressuri'ed air to the back side of
diaphragm 992 The compressed air is
applied directly to the li1uid column
separated by elastomeric diaphragms2
The compressed air moves thediaphragm a:ay from the center block
of the pump2 The opposite diaphragm is
pulled in by the shaft connected to the
pressuri'ed diaphragm2 Diaphragm 9&9
is no: on its air e!haust stroke; airbehind the diaphragm has been forced
out to atmosphere through the e!haust
port of the pump2 The movement of
diaphragm 9&9 to:ard the center block
of the pump creates a vacuum :ithin the
chamber 9&92 tmospheric pressure
forces fluid into the inlet manifold
forcing the inlet ball off its seat2
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2 i a
p h r a & m =
e c i p r o c a t i n & p u m p s
diaphragm, diaphragm99, reaches
the limit of its discharge stroke, the
air valve redirects pressuri'ed air to
the back side of diaphragm 9&92 The
pressuri'ed air forces diaphragm 9&9a:ay from the center block :hile
pulling diaphragm 99 to the center
block2 Diaphragm 9&9 forces the inlet
valve ball onto its seat due to the
hydraulic forces developed2 Thesesame hydraulic forces lift the
discharge valve ball, forcing fluid
flo: to flo: through the pump
discharge2 The movement of
diaphragm 99 to the center block of
the pump creates a vacuum :ithin
li1uid chamber 992 tmospheric
pressure forces fluid into the inlet
manifold of the pump2 The inlet valve
ball is forced off its seat allo:ing the
fluid being transferred to fill the
2iaphra&m eciprocatin& pumps
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7igure (8 =pon completion of the
stroke, the air valve again redirectsair to the back side of diaphragm
99, and starts diaphragm 9&9 on
its air e!haust stroke2 s the pump
reaches its original starting point,
each diaphragm has gone through
one air e!haust or one fluiddischarge stroke2 This constitutes
one complete pumping cycle2 The
pump may take several cycles to
become completely primed
depending on the conditions of theapplication2
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>ear and scre:
pumps
)i&h pressure and viscous 'luids)?sed in (amd 'or lube and seal oil
pumps air booster o' ammonia, 80@
A
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>ear pumps
)i&h pressure and viscous'luids
! seal oil pumps
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3ee the solution is pushed out of
the pump physically
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Bnly one &ear is used * !