Design Construction Ejector
Design Construction Ejector
Design Construction Ejector
CONSTKIJCTICH AND
KHS^K
A.
TAYLOR
fv.
il'lST
-}
621.64
K46
TES'i
lUiaois iasdtote
of Tecliaology
UNIVERS)'Ty LIBRARIES
AT 491
Kerr, V. A.
Design, construction and
test of a steam air-ejector
CARLI: Consortium
of
Libraries
in Illinois
http://www.archive.org/details/designconstructiOOkerr
V. A.
KERR AND
K. A.
TAYLOR
TO THE
president
and faculty
OF
BACHELOR OF SCIENCE
IN
MECHANICAL ENGINEERING
MAY
29, 1918
APPROVED:
OF TECHNOLOGY
GALVIN LIBRARY
ILLINOIS INSTITUTE
PAUL
35
V.
CHICAGO.
IL
60616
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^-^^^^ J??^:^^//.*^.,.^/^,.fM.diiB<u>.,
U^^^yR^^.
'iww^rin.s^ii-
^<^
DcAti of Ctlcurml ScudiM
TABLE OP CONTENTS
Pages
1.
1-15
2.
15-20
3.
20-26
4.
Method of Construction
26-29
5.
29-48
6.
Air-Ejector
28097
48-52
The Radojet.
Mfg. Co.
2.
Leblanc
4.
'
11
13
5.
19
6.
24
7.
8.
9.
25
32 & 33
37 & 38
51
1.
STEAM AIR-EJECTOR
INTRODUCTION
The study of the steam air-ejector opens
up
engineering profession.
It is hoped that
Institute of Technology.
The authors desire to express their gratitude
and indebtedness to their teacher. Professor
STEAI;!
AIR-EJECTOR
high
With
Hence an
3.
STEAM AIR-EJECTOR
machine which is most desirable.
Much has
brought forth.
investigation of Regnault.
(and hence
STEAM AIR-EJECTOR
C
H.
second stage.
through a strainer #1, through pipe #2, auxiliary steam valve #3, strainer #4, and into the
expansion nozzles
//5.
7/hile passing
^fl
This
nozzle passage.
In pass-
6.
7.
STEAJ/1
AIR- EJECTOR
The
which has
of a bronze steel.
accurately machined.
diffusers are
mixture into
8.
STEAM AIR-EJECTOR
for the boiler.
perature.
market.
diately
'C*
'C'.
Imme-
GATE VALVE
STEAM
FROM BOILER
WATER
OVERFLOW
INLET
CONDENSING
TANK
10.
STEAM AIR-EJECTOR
'Y',
The pump is
At the entrance to
mean
nozzle plates.
'Y
open type.
In this
mam
'c'
is opened
11.
12,
having
high vacuiim.
It ultimate-
The
13.
14.
STEAM AIR-EJECTOR
reason for this is that the alternate increasing and decreasing of the cross sectional area
of the jets is minimized by the contact of one
15.
Having given
dry.
Dia.
Bg
1/4"
28# vacuum
192 x .49
.94#
abs.
16.
STEAM AIR-EJECTOR
V
where,
"
^H^
224
Hg
H^.
^eat at 115#
H2
heat at 66. 7#
1188.7 B.T.U.
1145 B.T.U.
224
1188.7
1145
Xg
.964
'S'
.964 X 6.48
Vo
224 \/
^
Hn
"
Ho~(where
Hi at 115# A
"
Hq at .94#)
_2 224 \/ll88.7
885
(check)
::
778 (1188.7
1145)
WS/V
where
]_A
El
"
"
S ; specific volume
z w't"
of steam,
17.
STEM
where V
AIR- EJECTOR
.000341
W X 6.49
14B0
,Q11Q# steam/sec.
or .0778 X 3600
284# steam/hr.
18.
STEAM AIR-EJECTOR
It is necessary to allow for
of the steam.
The calculations
W X V
where F
no. foot-lbs.
"
wt. of steam,
"
"
F (at 4#)
X 3370
d ~-
/144 X 4
3.
A,
1416
::
13.65 ^.00705
19.
rHEORfinCAL A/OZZLE
.?= 2r^^
/Vfi^^.
\ror/IL'f4'T\Qi/ALtry S/^
//B0.7
/.oo
J.85
//'9S
.9<V
6.^9
93S
/Of99
.ae^
a.G.8
ffoe
/03 9
iOOB
9B3
.&86>
\2'^,40Q
9.8
^0I0
\C>,BOO looo'^o(,\
2*f^O
.3/3
/73.S
Mt
\
\.o0034l
f*/eo
\^/.S
3S'O.B
\DtA-fN' POUNDS
4>.i5
\^7.B7
SO. J^T
^.8Q
.a^H
.7*>/
Fr-LB
4i.7*i
3(?i,0
f/4r^900
.000
7(y
\t^J'ZO(i [oo/^f
.2.S
V6.<7
.ays'
^z.H
77
QS.t
.3
3<V3
I
9S0
\/l7S
3390
&r^jOoo
t3H,S'<90
.OO3T0
.OOHS"
.33'd.
'ST
'/
3,^
/^7
20.
STEAM AIR-EJECTOR
1/4"
Pi
lOC^ ga.
P2 =
.58 X 115#
.000341 sq.ft.
115# abs.
z
1.92 x .49
throat.
Pg
28" vacuum
.94# abs.
pressure.
The energy loss is converted into heat and
Assuming a
224
\J(1
y)
(H^ - Hg)
'y'
21,
STEAM AIR-EJECTOR
"
1188.7 B. T. U.
heat at 115#
H2
heat at 66. 7#
224
(1 - O'l)
224
\/'
.9 X 43.7
where H^
=
=
1145 B.T.U.
(1188.7
1145)
entrance.
Xi
real quality,
Xq
theoretical quality
r3
Xi
Xg
Xq
y (Hi
,1 X (1 188.7
886)
Iq
Hq)
Increase in quality;
'
1035.6
.0294
Real quality
.0294
.791
.0294
::
778 X
778 X \/{l
\f{l ' y)
-
(^r^^H^T"
0.1)
(1188.7
1145)
22.
STEAM AIR-EJfiCTOR
31,000 ft. lbs. of energy at throat
X U
- TSX]_
V
where A
"
<^t.
"
X3
"
Uo
A3
but, Ai
d =
0778 X 81 X 550.8
3760
1/4 X 3.1416 X d2
\/.
*7b8d.^
Q05Q8
::
FOOT-LBS. OF ENERGY
F
W V
g
.0778 X 5760
52.2
23.
STEAM AIR-EJECTOR
LENGTH OP NOZZLE.
'L'
rV15 X
r
Vl5 X
where
'a'
dia. at throat.
.25"
1 & 15/16"
24.
25.
CONOENSCB.
f^RBSS,
GAUG
lu ^^
3 i.mov^-
z'Laov\f.
rHCSS. GAt/GJS
^i.XZx/'/tj:f.r.'
CA L. OK
m re/^
i'-^xii^-^/^rX
i^pifie
'rTijg,"meo.'r:
9"P/f>e
-I
>//
H'a.i^AAfo/^ere-
Sr/l/^
>4//?-^/^C TOR.
CHtCASO.
MfitelMiMMMiaiaiMiiMi
ii.L,
26.
STEMt AIR-EJECTOR
METHOD OF CONSTRUCTION
The upper combining shell was made of cast
iron.
out.
this piece.
with
27.
STEAlvl
AIR-EJECTOR
were
The upper and lower combining shells
fitted together, by means of the centering
shoulder.
of between 1/64
in contact, it left an opening
the circamference
and 1/100 of an inch all around
By inserting
a pack-
joint, a known
ing of a known thickness in the
be obtainwidth of opening of the nozzle could
ed.
on
Thehozzle was made of brass and filled
which causes
the inside to reduce the friction,
steam.
a loss of energy in the
Threads were
discharge,
cut, on the opposite end from the
nozzle
leading up to the shoulder, so that the
top plate.
could be screwed tight up against the
inserted between
By this means washers could be
shoulder and the top plate, if it was desirthe
28.
STEAiVl
AIR-EJECTOR
The nozzle
29.
illustration
and its construction is given in the
#A2.
and
In this illustration all the fittings
plane
apparatus are sho;vn to be swung up into the
of the paper.
In illustrations
#k-^
when it was
actual apparatus is shown as it was
being tested.
ejector. The
feeds direct from the boiler to the
boiler, it was
steam coming so direct from the
of
permissable to assume that it had a quality
tests that
100^, in the calculations of the
follow.
calculations
This was also assumed in the
of the nozzle.
pipe #9,
The live dry steam, coming through
the primary
goes through valve #8 and enters
nozzle at #1.
30.
STEM AIR-EJECTOR
tlon of the first nozzle alone, assuming that
the exhaust.
This pipe
ejector.
The exhaust leads to a counter-current
mosphere.
beer;
of condenser.
31.
STEAM AIR-EJECTOR
the air, which had been entrained in the
'Water-hammer'.
32,
33,
34.
STEAM AIR-EJECTOR
Started through the condenser.
secondary nozzle.
combining shell.
high
The valve
35.
STEAM AIR-EJECTOR
valve #6.
opened full.
The boiler pressure was read on gauges
#4 and #5.
frlO,
This
The amount of
36.
STEAM AIR-EJECTOR
across the lower combining shell.
By follow-
>^s
a re-
Vi/hen
37.
COA/O/r/O/VS OF
OPER/IT/Of/
STEflM
F?F^^/^
PRessme cu/^rFlR
G/iO:
MOf?
SrS^M
10S.
f^R
/^i/R
//V-
Pf9 IB.
/9/A'
O^
^T^JlM
LB.
^TE/IM
/'
"
jO/^. /J
(resT
OPN
oc/riE
.100
T.
'*s)
/^A/0i2l.
LONG
AT
A/O GASA<r
STUDD
JOINT
/o3
6.^6
//^.
^gm
YALVe VALVE
OPEN dOSEO
LONG
NOSiBLE
or
/LBS. >///?
FT fER
Ffff^E W//?
CO.
.S3S
38.
COND/TION6 OF
OP^f?^TJON
OF ^/R-FJFCTOR
srEftM
P^e^a^^
'''"'^
/=?? /f//?
FT PR
^^^^
CO.
39.
STEM! AIR-EJECTOR
out in order to lessen the opening in the
secondary nozzle.
pansion.
This was
40.
STEAM AIR-EJECTOR
expansion.
a vacuuin of 2.75"
It main-
41.
STEAM AIR-EJECTOR
great an angle.
doubtedly a rolling-back action that destroyed any vacuum which was created by the primary
nozzle.
This space
42.
STEAM AIR-EJECTOR
comingled air and steam coming from the primary
nozzle.
With such
a space present,
the vacuum
pressure.
To overcome this, it was thought that an
velocity
be entirely filled by a strean of high
gases.
43.
vacuum.
ejector.
In
This shoulder
v/as
44.
This
Inside of
and 1/2"
combining shell.
thie
ejector.
45.
The pipe
alone.
v/as
being
46.
ejector.
of efficiency.
results.
It is hoped that the following design will
47.
STEAM AIR-EJECTOR
48.
STEAM AIR-EJECTOR
THE PROPOSED
NE?;
To utilize
design
this principle to a better advantage, the
was changed.
of different
nozzle, the new design consists mainly
inlet, #6.
into
The commingled air and steam pass
combining
entrained by the jet #9, in the lower
chamber.
final
combining shell was reconstructed on the
drawing.
case.
The steam and air enter, in this
49.
This forms
In this manner
walls.
50.
STEAM AIR-EJECTOR
is tapped for the steam line.
A hole is drill-
in the middle of
ed and tapped from the bottom,
This is a
through #16.
against the atmospheric pressure,
design, the
In the analysis of the first
new ejector will
authors feel confident that this
first one did.
give far better results than the
had the time
The authors regret not having
so that they might
to build this second machine,
instead of negative
have presented positive,
results.
51.
K-
i^^^s:
msA
H"
7SSS!!SSSS!!!!!\