JOHNSON
Centrifugal Fans
and Rotary Blowers
ft
Mechanical Engineering
a s.
1 900
UNTVESSITTOF
nx. unAn 1
****** * # * * *
* * * * * * * * 1 *
SH i * S aB .**v%**v% + *%*;
-<
Ipi ifl I iS * * - SsBpI?'* * * * * * ******** * *
, * + ********** * * *
| | A i I I * **********<.****<-**** + ****^ ^ • if earning anb labor. § mk % ^ ^
JUniversity of Illinois.
J|
* | CLASS. BOOK. VOLUME.# | | \
'
1 ^OD ^ I f \\\ *§ ft * '»jk' :* i^§ Accession No.
|
* 1 | v i * * * * * * * * * * *
% * m I * * | * # * * + * * *. *
•** i **>** ********* * * * * * * *
* * * * * * * - * * t * *•
*
i * # * * i § # * * * *i
* *
*
| |«| | * , * § * * * * * * * *
**** * ****** i | * * .
*
i * *- * i I I ******* * ** ss * i * * * * * * * * * * §
* **
* *
* **
* **
* * ** *
*
* 4*
^***^********* **
4 * * * ** -* * + 4
* * * - *|
* * ^. * * ,* *******
*. I! *. * '
||'
|| H* *- * || * * 4- i
*, * * * * || |p
* * *" * ^ IP
* • | * 1* * f *' * i
* *- Nfe "4* # *> ^ ^* * * § I §******* H * * * # * *
j
^ * * * * * * * * - * # . f * §
** * * *
* * * *
* ' * ' * *
*************-*.**** * *
* * * U * * * # 4 in * * * |
********<* * * * * * * *
-* * * * * *^ *- * * *
^ * * *- * *«********-*. *.*
M i ' I I I* * * #Sfe:' * * * * # ***********m Is^f!*! I it '
ip * I**,>*,*.***** * ** * * * * * * * * "* *
* *, ^ * *, *, * * * Sfe m * ter* ** * * * * * * *
* * * * * **. * * ^ * * *
^ * =««***-*>***-***** * ' * f,£,***** * *^* * if, '* * * m * *
* -* jL * * * * > * ** * * - * * # * # * * i
*
* * f i *^ * ^ + ^*
* * * I * § ***.**** **-***=• •
m * * i H H*. i I I
* * * *^ * * ^ *• * * * * * *
Centrifugal Fans and Rotary Blowers
... BY ...
CHARLES SUNDERLAND JOHNSON
THESIS
FOR THE DEGREE OF BACHELOR OF SCIENCE
IX MECHANICAL ENGINEERING
IX THE
COLLEGE OF ENGINEERING
OF THE
UNIVERSITY OF ILLINOIS
PRESENTED JUNE, 1 <)()()
UNIVERSITY OF ILLINOIS
May 31, 1000.
THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION BT
Charles Sunder! and Johnson
entitled Centrifugal Fans and Rotary Blowers
IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE DEGREE
of Bachelor., of Science in... Mechanical Engineer in^ ,
head of department of Mechanical Engineering.
Digitized by the Internet Archive
in 2013
http://archive.org/details/centrifugalfansrOOjohn
2
CENTRIFUGAL FANS & ROTARY BLOWERS.
For the movement of large volumes of air there are five gen-
eral types of machines. These are the disk or propeller fan, the
centrifugal fan, the rotary blower, the piston blower and the
steam jet blower.
Each of these machines seems to have its own field of adapt-
ability to which it is best suited and in which it should always
be used if efficient service is desired. The disk or propeller
fan is best suited for moving almost any volume of air when prac-
tically no resistance is offered to its flow. When a resistance
corresponding to from three fourths of an ounce to sixteen ounces
per square inch is found then the centrifugal fan is used. The
rotary blower is probably best adapted for handling air at from
one to five pounds per square inch. If the pressure is higher
than this then the piston blower comes into use. The steam- jet
finds a field of its own not on account of any mechanical effi-
ciency but because of its simplicity und great adaptability in
producing the draft in locomotives and other boilers. In its use
the moisture which comes from the steam plays an important part
in bpeaking up the clinkers that are formed on the grates. This
makes the steam-jet very useful when hard coal is used.
The above machines may be classified according to their form
and construction or according to their use.
46838
3
A classification as to construction:
(risk Fan.)
Pans . (
)
(Centrifugal Fan.
(Piston Blower.)
Positive Blowers. (
)
(Rotary Blower.
Steam- jet
.
A classification as to use)
(Disk Fan.)i
Exhausters. (Centrifugal Fan.
)
( $team- j e t
.
(Piston Blowers.)
Blowers. (Rotary Blowers.)
(Centrifugal Fan or Blower.
These classifications serve to show the relation between the
centrifugal fan, rotary blower and other air propelling machines.
Constructive features of rotary blowers.
There are a number of makes of rotary blowers on the market
and it is interesting to study the different mechanisms that have
been devised to accomplish the sane results. Each of these has
its own features. They all depend, however, upon the one working
principle that tha air is confined between two surfaces, station-
ary or movable, compressed by a reduction of volume and then alio
allowed to escape at the pressure thus obtained. It is from this
principle that the name "positive blower" is probably derived.
4
Tliis prieiple is apparently perfect and would undoubtedly
yield good results if friction and leakage could be eliminated.
But these difficulties are so marked that they greatly reduce the
mechanical efficiency. Another objection found is the frequent
necessity for a renewal of working parts.
The Baker Rotary Blower.
The external case of this blower is made of boiler iron,
turned up truly and inserted into the heads of the machine. The
heads are made of cast iron and are securely bolted to the bed
plate. These heads are bolted together longitudinally by iron
rods on the outside of the case. The drum concentric with the
case as well as trie two lower drums are solid castings and are
turned as true as possible. The lower drums act as abutments for
the blades. The motion of the air is as indicated on the drawings.
Gearing on the exterior of the case serves to turn the drums and
keep them in their proper relative positions. The lower drums
are revolved in opposite direction from the upper drum. A wire
guard or screen is placed over the inlet to prevent anything from
entering that might injure the working of the blower. The driv-
ing pulley is keyed to the s af t of the upper drum.
This blower offers considerable chance for slip or leakage
back into the inlet chamber. Besides the air which can get by the
drums and blades the space between the two lower drums is filled
every revolution with air from the discharge side and this is
then allowed to escape into the inlet chamber.
Baker B/ower.
6
The Mackenzie Blower.
The casing of this blower is also made of boiler iron. The
blades are pivoted to a shaft concentric wit?i the casing and are
revolved by means of the drum. This drum has a diameter of about
two thirds that of the casing and is placed tangent to the casing
between the inlet and outlet openings. The driving pulley is
keyed to the shaft of the drum.
The Reichhelm Pressure Blower.
The casing of this blower is made of cast iron. A shaft
which carries the driving pulley extends through the casing some-
what below the center. On this shaft a cast iron drum is fastened.
This drum has four recesses into which the blades or vanes fit.
A guide ring is turned into each head of the blower and into these
rings are four blocks, whici* are pivoted to the four blades. The
blades are revolved by means of the drum and are forced in and out
by the guide rings and blocks. An air chamber is placed over the
discharge pipe with the intention of decreasing the pulsations of
the blast.
This blower is advertised in four sizes capable of discharg-
ing from sixty-five to five hundred and eighty-five feet of air
at a pressure of from one pound to four pounds per square inch.
The Disstons Pressure Blower.
Within the casing of this machine are two revolving bodies
working together as indicated and geared by a pair of equal gears
on the outside of the casing. One of these bodies is a drum turned
7
Plate H.
Mackenzie's Blower
3
Plate IK.
Reich helm Blower.
9
Plate IE
10
to fit the casing snugly and having two cavities for the piston to
work in. The piston is also made of cast iron. This piston does
nearly all of the work of the blower, only a small portion of the
air that enters the cavities of the drum being forced into the
discharge opening.
The Roots Blower.
This blower is made on entirely different plans from those
before described. Nearly the entire machine is made of cast iron,
the only other metal being t2ie two steel shafts. The casing is
oval in cross section, having the discharge and inlet openings
either in the top and bottom or in the two sides of the machine.
In the latter case the impellers are placed one above the other.
The impellers are made of cast iron and are turned up upon a
machine especially designed for the purpose. All the curves of
the external surfaces are true circles. Gearing is placed on the
end of the casing and the driving pulley is keyed to one of the
shafts. The largest sizes of this blower are capable of discharg-
ing nineteen thousand six hundred cubic feet of air per minute at
the pressures used in cupola practice.
The Green 1 s Rotary Blower.
The Green, as well as the Connersville blower, is almost exact-
ly like the Root blower. As is shown in the drawing the impellers
of the Green b.lowar are different in design and two rollers are
keyed to each s riaft to prevent the impeller from pounding, should
the bearings wear, the shell, gearing and other details are
almost identical with the Roots. Twelve sizes a*e made capable
Plate Y
\
Plate YL
/3
of discharging up to 15000 cubic fset per minute.
The Connersville Blower.
All other details of this blower besides the impellers are
the sane as the Roots blower. The impellers of this machine are
flatter at the ends and thicker at the middle. This blower is al-
so made in si7.es capable of discharging up to 15000 cubic feet of
air per minute.
In the records of the British patent office the rotary
blowers and rotary engines are described in the same volume.
The rotary blowers are divided into three classes, "cresent shaped
chamber types" such as the Mackenzie and Riechhelm blowers,
"annular chamber type" such as the Disstons and Baker blowers, and
the "Root blower type" such as the Roots, Green and Connersville
blowers. Some eight or ten hundred machines are patented as blow-
ers, rotary engines or both.
TESTS OP ROTARY BLOWERS.
Only one set of tests of this character was found. This was
a set of tests by Prof. H. M. Howe on trie "Coraparit ive efficiency
of fans and positive blowers" given in the transactions of the
Institutte of Mining Engineers, Vol. 10, pg. 482.
The experiments were undertaken with the idea of proving that
the Baker blower was more efficient than the fan blower. The
results, much to the suprise of the authors, proved that the fan
is more efficient than the Baker Blower for pressures as high as
twenty ounces per square inch. The air was measured by noting the
pressure of discharge through one, two or three six inch circular
Plate JZLL
C on tie rsvi lie Blower.
16
orifices and calculating the volume from these results. In com-
paring the results they are all reduced to the discharge through
one six inch circular orifice. A No. 4 1/2 and 5 1/2 Baker
blower, a No. 1/4 Root blower, a No. 10 Sturtevant fan and- a "G."
Hawkins fan were tested and the results plotted. The results have
been copied and are given on an accompaning sheet (see pg./jT ).
In his conclusion he says fans and positive blowers are more
efficient when working near their maximum capacity. Therefore,
when a great variation of quanity of air is required, a number of
small blowers would be more efficient than one large one. The cost
of positive blowers is about four times that of fans for the same
capacity. The Baker blower shows about ten per cent less effi-
ciency than the fan blowers.
This comparison is, however, severe as the pressure is some-
what lower than that for which the positive blower is designed to
work against.
Constructive Features of Centrifugal Pans.
The following types of centrifugal fansare advertised by
nearly every company that manufactures the centrifugal fan:
Steel pressure blowers,; Volume blowers; Volume exhausters; Steel
plate blowers and exhausters.
17
STEEL PRESSURE BLOWERS.
This is a form of fan designed to discharge a snail volume
of air at a high pressure. They are capable of producing a pressure
of as high as twenty ounces per square inch and are adapted for
use with cupolas, forger and some types of mechanical stokers.
In order to obtain a small volume and high pressure these fans
are made with wheels of small widths as compared to their diameter.
.
The blades are usually five, six or eight in number, are wider at
their inner edges than at the circumference of the wheel and are
curved backwards to decrease the noise of the blast. The Sturte?
vant blower is made with six full blades and eighteen small blades
of about half the length as the others placed in between the larger
ones. The blades are riveted to steel rt T" irons which are cast in
trie hub. Conical sideplates which extend from inlet to outlet are
riveted to trie sides of the blades. The casing is made of cast i
iron and is of a spiral form and usually has the discharge opening
horizontal. The shaft Is steel and is hung in two bearings one
on either side of the fan. These bearings are always large and
self-oiling, the chain, ring and wick type being used. The pedes-
tals are either cast solid to the casing or are cast separate and
bolted to the casing. - Both one and two driving pulleys are used.
These blowers can be obtained mounted on an adjustable bed plate
but are never directly connected to an engine as the relative
speed is too high.
VOLWIE BLOWERS.
This type of blower is designed to discharge a conside rable
volume of air at a moderate pressure (two to ten ounces per square
inch.). In appearance they are very similar to the pressure
blower. The casing, however, is wider and the outlet larger.
The fan blades are of an equal width the whole length and are bent
backwards the sa.:e as in thel pressure blower. Only one driving
pulley is used. The volume blower is also mounted on an adjustable
bed plate but is never direct connected to an engine. A table
of capacities of these blowers is given with this thesis..
(See pg.5"f ) •
Volume Exhausters.
The construction of a volume exhauster is similar to a volume
blower except that there is only one inlet and that 4s provided
with a flange for pipe connections. The bearings are both placed
on the opposite side from the inlet and the driving pulley placed
between them.
STEEL PLATE BLOWERS AND EXHAUSTERS.
These fans are designed to handle larger volumes of air at
lower pressures than the volume blowers and exhausters. The
casing is nade of steel plate and is ribbed with angle irons to
give rigidity. The fan wheels have one, two or sometimes three
spiders supporting eight or more blades, the number depending upon
trie size of the fan. The blades are usually made straight, but
in some cases where the fans must not . iake any noise they are
bent backwards. The discharge opening can be in any direction,
IS
top or bottom horizontal, up or down vertical, or at any desired
angle. Some fans are made with two or more discharge openings.
These fans are run at lower rotative speed, the speed depending
upon the size. In some of the larger sizes only three-quarters of
the fan is housed in steel plate, the remainder being xonstructed
of brick, wood or some cheap material to save expense. They can
be obtained with direct connected engines.
Tests of Centrifugal Fans.
"In the study of air propellers there is a great difficulty
in taking cofcrect measurements of the pressure and quantity of air
delivered if the velocity of the stream is at all great. From
this cause experiments apparently conducted with the greatest
accuracy have of ted shown a fan under test to give an efficiency of
over 100/? and therefore, general statements of the efficiency of
fans should be received with great caution."
In Vol. 123 (1895) of the Proceedingsof the Institute of
Civil Engineers a set of experiments are recorded by H. Heenan and
V/m. Gilbert. These experiments are teery unique and are the most
thorough of any that were found. They had for their object:
(1) "To determine the best shape of blade and fan case in order to
obtain a minimum expenditure of power when producing any given
output, i.e.- the best type of fan; (2) The standard type being
elected to obtain data whereby the proper diameter of the standard
fan and its most economical speed could be determined for any given
output of air af required pressure.
The arrangement of the apparatus was good, gpeat care being
taken to see that there would be no doubt as to the accuracy of
20
the results.
"The experiments proved that a fan with a few simple blades
gives the best results, provided the form of the blades and casing
are designed to suit the kind of work required. Fans of a more
complex design have too large an internal resistance to give a
high mechanical efficiency, although they may have to be used if
high pressures are essential."
Four different blades having different tip angles and differ-
ent angles at the inlet, were tested in a fan of the ordinary
design. A b n ade having a backward slope at the inlet and then
bending until it is perpendicular to trie circumference was found
to give the best results and to maintain a high pressure as the
volume increased but when the discharge approached close. to the
maximum it dropped rapidly to zero. A blade which sloped back-
ward the whole length gave considerably lower efficiency, and
allowed the compression to decrease rapidly as the volume increased.
In the transactions of the American Society of Mechanical
Engineers a set of experiments are given by H. I. Snell on a
Sturtevant blower 23" in diameter and 6 5/G inches wide, inlet
12 1/2 inches in diameter on both sides, and eight blades having
an area of 45.49 square inches.
The air was discharged through a conical tube with sides
tapered at an angle of 3 1/2 degrees. Vena contracta 80^.
2/
TABLE OP TESTS OP PANS BY H. I. SNELL.
TheoriticalV U X UiiltJ V U x UiiitJ volume that can
R. discharge Press
.
of air per be dischargedNo r . . . . In C\7 t, p >• m i n H P H P per rain. H.P. Eff
.
1X 1519X X %7 o 3 50 o . 80 1048 •
2*-* 1479 3 . 50 406 1 . 15 353 1048 .337
3 1480 10X w 3 . 50 676 1.30 520 1048 .496
4 20 3 5*0 1353 1 95 6 94 1048 .66
5 1485 28 3 . 50 1894 2.55 742 1048 .709
AW 1485 36 3 . 40 2400 3 . 10 774 1078 .718
7 1465 40 3.25 2605 3.30 790 1126 .70
8 1451 44 2.88 2686 3.50 767 1277 .601
9 1468 44 3.00 2752 3.55 7 75 1222 .665
10 1415 44 2.75 2636 3 . 30 799 1333 .60
11 1415 48 2.75 2873 3.45 833 1333 .613
12 1500 48 3.00 3002 3.80 7.-J0 1222 .646
13 1471 48 2.888 2938 3.70 794 1277 .626.
14 1426 89.5 2.38 3972 4.80 827 1544 .536
22
Exper iments to dertermine the effect of speed of Fan.
R Volume inp . 11
.
Pressure o£. cu.ft. per min. H. P. Ef f
.
600 .50 1336 .25 .72
800 .88 1787 .70 .61
1000 1.38 2245 1.35 .62
1200 2.00 2712 2.20 .67
1400 2.75 3177 3.45 .69
1600 3.80 3670 5.10 .74
1800 4.80 4172 8.00 .68
2000 5 . 95 4674 11.40 .66
In his remarks on the tests, he says, "The greatest efficiency
when the discharge is free and open and the area of inlet opens
equals the capacity of the fan wheel."
Prom experiments already given it will be seen that we may
expect to receive back 65 to 75/b of the power applied and no morel'
There is a great variation in the opinion of different author-
ities as to the efficiency a fan will give. In the experiments
before refered to be Heenan and Gilbert, mechanical efficiencies
as high as 90^f are shown. Prof. Carpenter says that any test that
shows over 50/S is probably in error while these experiments of H.
I. Snell show as high as 14%. Weisbach and other authorities
give only about 30^f.
23
Series of Tests on Centrifugal Fan in Mechanical
Engineering Laboratory, University of Illinois.
The objeet of this experiment was to obtain a complete set
of data which wo*ild show what the fan was doing under all possi-
ble conditions.
Description of fan: The fan was a Buffalo Forge Co's "No. 8
B. Volume Blower". It is advertised, for use with boilers, heating
furnaces, forges and etc. The principle dimensions are:-
(See drawing plate JQU ) .
Height--- 48"
Length 47 1/2"
Total Width. rr 40"
Diam. of pulley 8 1/2"
Width of " 7 1/2"
Diam. of wheel 28"
Width " " 11"
No. of blades 5", curve back 3"
Size " " 11 "x9"-- shape
Area of blades 88 sq. in.
Diam. of outlet (cutside pipe flange) 16 1/2"
" " (inside):
15"
Area of outlet 132.7 sq. in.
Diam. of inlet ( pulley side) 15 1/2"
Area of inlet ( pulley side ) 86.4 sq. in.
The area of pulley was subtracted as it obstructed
2 3/1
/
2i
the inlet.
Diam. of inlet (opposite side) 13 1/2O It
Area of inlet (opposite side) 119 sq. in.
The area of bearing being subtracted.
area of inlet.Ratio 1.56
area of outlet
Diam. of shaft
Length of bearings
1 3/4"
— 9" (ring feed type)
Distance between bearings 28"
Arrangement of apparatus:- This fan was at first belted to
the Ball engine. This engine is supposed to be run at about
320 R. P. M. and has a fly wheel of 36" diameter. It was thought
that the engine could be speeded up until a proper belt speed
was attained buttthis was found to be impracticable. The fan was
t en attached to the Myer engine. This engine has a 54" fly
wheil, and is designed to run at about 250 R. P. M. But by pro-
perly arranging the weights on the governor arm and changing the
ratio of the governor pulleys the engine was made to regulate to
any desired speed.
Fourteen feet of 16 1/2" galvanized iron pipe was attached
to the outlet of the fan. A Buffalo Forge Co., gate was placed
in this pipe four and one half feet from the fan. In this gate
were placed tin slides having different sized orifices. At firdt
this gate was placed about six inches from the fan but the
static pressure was found to vary considerable in different sec-
tions of the pipe and hence it was thought best to place the gate
some distance fro the fan.
1L
27
The static pressure was measured in the pipe about ten inches
behind the gate. The temperature was also taken inside the pipe.
As the dynamic pressure varies considerable in different sec-
tions of the pipe a special device was made whereby one reading
could be taken which would be approximately, if not exactly, an
average of all the pressure in the different sections. This device
shown on plate IX 5consisted of nine bent tubes 1/4" in diame-
ter which extended into the pipe and opened into the current.
The ends of these tubes were so placed as to obtain the velocities
for different but approximately equal areas of the cross-sections
of the pipe. A hollow ring extends around this pipe and into this
the tubes opened. This hollow ring acted as a chamber for aver-
aging the different pressures. The action of this arrangement
was supposed to be thus:- If the pressure in one of the nine tubes
was greater than in any other then a flow of air would result,
going in at the first tube and out the other until the pressure
in the ring was an average between the pressures in the two tubes.
The same action taking place between all the tubes would give a
pressure in the ring which would be an average of all the pressures.
A rubber tube was attached to this ring and to the pressure gauge.
At first an attempt was made to measure the pressure by an
ordinary ^itot tube ("U 11 tube) and water but this was found to fluc-
uate very rapidly, thus making it impossible to obtain a reading
closer than to 1/4 of an inch in water. A slanting tube was then
tried but it also showed the same difficulty. Two gauges were
then constructed on a plan given by Wm. Kent in Vol. 10, A.S.M.E.
The gauges were exactly alike except that the one used to
2.7/g.
g2&
Plate U
-16
Wafer-11.3
Sca le bed\ g^Bg
Detail^) of Gauges
and
Device for obtaining dynamic pressure.
loo
Scale '/&
f\<r-Spout for attaching Gauge tube.
£3
j
measure the static pressure was 24" high while the other was
only 10" high.
For each gauge two pans were made, one having a diameter of
about 16" and the other a diameter ( //. 5 ') such that its area
was 100 square inch. The height was 24" for one gauge and 10" for
the other. The 16" pan was half filled with water and placed on
the platform of a pair of scales. The other pan was inverted
inside this and fastened to a frame which in turn was fastened
rigidly to the floor or table on which the scales rested. Care
was taken to see that there was no contact between these pans.
A rubber tube led from a spout in the inverted pan to the blast
pipe. The pressure in the blast pipe passed through the rubber
tube into the inverted pan and thus exerted a downward pressure
on the water inside the pan. This total pressure was weighed on
the scales. This result after being divided by 100 gave the
pressure per square inch accurately to the second decimal place.
In taking readings one person took the speed of the engine
while another took that of the fan, hand speed counters being used
for both cases. Immediately after taking the speed one person
took the indicator cards while the other took the readings from
the gauges, thermometer and barometer. Seven readings were taken
for each speed, one for full discharge, one for no discharge and
five for intermediate discharges. Duplicate readings were taken
in each case.
The method of figuring the volume was as follows:
Let V a veloc. in feet per min. of the discharge .
V ~60[/2 gh where h-=. head in ft. air column.
29
T)
h a? .) when p =- pressure in ounces per sq. in. andd
d ssr density.
. . Vx= 60 x 3 x 802d
Let B zr barometer reading in inches of mercury.
T =z temperature in Pahr.
1.3253 (§ BDn- from Kent.
460 +• T:
Vrr 60 x 3 x 8.02(460 + T) P
1.3253 4- B
3 1254.12(460 + T) P
B
Q-zz volume in cu. ft. per rain.
Q.~ 1.39 X 1254.12(460 + T) P
B
- 1743.2(460 -t T ) P
B
1.39 z area of pipe when veloc. press, was taken.
The power used was determined from the indicator cards
taken from the engine. No attempt was made to separate the power
used by the fan from the engine friction, the engine and fan
being considered as a unit as they would occur when in use.
The results for each speed were plotted. The volume in cubic
feet per minute was layed off as abscissa and the compression in
ounces per square inch, the total pressure( static plus dynamic),
the engine H. P., the blast H. P. and the mechanical efficiency
as ordinates.
30
In each case the static pressure at first slightly increases
with the volume and then drops radidly as the volume increases
until the gate is wide open when it becomes zero.
The engine horse power gives almost a straight line.
The horse power represented by the bla&t ( which is the total
pressure into the volume) increases with the volume when the
pressure is high, but when the pressure becomes low and the volume
large it drops off suddenly. This drop is probably due to the
increased friction which the air encounters in passing through
the fan. The efficiency curves also shows a similar drop, which
also indicates that there is considerable lost power when a large
volume is discharged.
Another set of curves is given where the volume is plotted
against the speed. These show cleanly that the volume varies as
the speed.
DATA & RESULTS FOR TIP SPEED OP 14000 FT. PER MIN.
R. Vel. Stat,. Blast Eng.No. P.M. Head. Bead Volume Temr . Bar. H.P. H.P. Eff.
|0Z. PER iq, in.
1 1900 2.26 11145 72 2.93 6.84 38. .18»
1905 1.08 4.80 7704 72 " 12.35 29.6 .415
3 |905 .63 6.624 5884 72 " 11.64 25.6 .462
S }900 .05 9.25 1688 67 " 4.28 14.8 .282
5 1895 8.25 67 "0 8.8 .0
Blast MP
TolalPress
brat/c Press.
1000 2600 5000 WO 5000 6000 7000 BOW 9000 7000 //0\
Volume in cu.ft. per mm.
30
28
26
2f
22
20
18
16
li
12
10
6
2
SO
60
70
60
50
fO
30
20
10
6
6
5
/
t 4
33
DATA & RE oriT 70• j iv 'j J. o wn tiprun ji l j • Ji rj i ,1
)
OF 13000 FT. ppp *JTTTJ1 M i. a .
R Vel. Vol lima Blast Pin nf
No. P.M. Head Head Tenn . Bar. H.P. H.P. Eff
.
OZ PR. 5 a?. I ri<
1 1760 1.91 10340 73 29.0 5.37 29.8 .181
2 1773 1.94 10320 73 it 5.46 29.9 .186
3 1780 1.46 2.12 8957 74 it 8.75 28.3 .31
4 1778 1.47 2.13 8988 74 ii 8.82 27.7 .319
5 1780 .99 4.17 7392 73 n 10. 40 25.1 .41
6 1765 .94 4.16 7187 73 ii 9.996 24.4 .41
7 1778 .53 5.73 5385 71 ii 9.21 22.2 .415
8 1781 .54 5.76 3631 71 ii 9.25 22.3. .439
9 1769 .24 7.26 3555 71 ii 7. 49 17.8 .406
10 1768 .23 7.20 1284 68 ii 7.20 18. .40
11 1769 .03 7.84 1284 69 it 2.76 12.9 .213
12 1770 .03 7.82 69 it 2.75 12.8 .214
.13 1773 7.37 70 ii 9.
14 1778 7.39 70 ii 8.6
I l l llll l l l ll l l ll l llllliii i i mn i i i m ii ii i i
Character/ stic curves of a
Buffalo Forg e Co !s Vtilum e Bio wenftp spe ed of blades 15000 ft. per in in.
«En$. H.P
Blast H. P.
Total Press.
Efficiency
Static Press.
2000 3000 1000 5000 6000 7000 8000 9000 ICOH UOOO
volume in cu.fr. per min.
3D
26
26
21
22.
20
18
/6
If
t2
10
6
6
90
2
80
70
60
50
to
dO
20
10
to
O
8
JL
6
5
3
2
I
EUGENE DIETZGEN CO.. CHICAGO
DATA & RESULTS FOR TIP SPEED OF 12000 FT. PER MIN.
35
No.R.
P.M.Vel.Head Head Volume Temp. Bar.
Blas^H.P.
Eng.H.P. Eff.
1 1640 1.49 9150 84 29.3 3.71 25.2 .147
2 1635 1.49 9150 85 h 3.71 25.1 .148
5 1610 1.20 1.50 8210 84 M 6.04 21.7 .278
4 1628 1.20 1.52 8210 83 II 6.09 22.5 .27
f> 1640 .81 3.42 6740 85 II 7. 77 20.7 .3 75
6 1650 .82 3.45 6790 86 II 7.90 19.9 .397
7 1620 .45 4.86 5030 85 II 7.26 17.1 .425
8 1630 .46 4.82 5080 85 II 7.31 17.1 .428
9 1625 .19 6.08 3270 84 II 5.58 14.6 .383
10 1622 .20 6.12 3350 84 II 5.78 13. .445
11 1630 .03 6.64 1300 84 II 2.36 9.7 .244
12 1650 .03 6.64 1300 84 II 2.36 9.96 .237
13 1635 6.03 84 II 6.76
14 1648 6.16 85 II 6.34
Characteristic curves a/ aBuffalo For ge Co's Volume Blower.
Tip speed cf blades 12000 ft. pe r min.
Eng. H.P.
EUGENE DIETZGEN CO., CHICAGO. 'olume in cu.ft. per min
9
37
DATA & RESULTS FOR TIP SPEl'JD OF 11000 FT. PER MIN.
R. Vel. Stat. Blast -Eng. Eff
.
No. Head Head Volume Temn . Bar
.
H.P. H.P.1 1505 1.37 8753 84 29.3 3.35 17.7 .189
2 1502 1.37 8753 84 ft 3.35 18.3 .186
3 1500 .99 1 . 20 7445 83 w 3.53 17.6 .200
4 1430 .99 1.20 7445 83 rl 3.53 16.7 .211
5 1498 .65 3.09 6032 83 ri 6.15 15.0 .41
6 1495 .63 2.90 5926 84 it 5 . 70 14.1 .405
7 1500 .37 4.05 4551 82 it 5.49 13.7 .40
8 1500 .37 4.08 4551 82 ii 5.52 13.5 .409
9 1500 .16 5.17 29 96 80 it 4.36 11.7 .373
10 1500 .17 5.34 3085 80 ti 4.64 11.6 .4
11 1490 .02 5 . 23 1058 81 ii 1.51 8.2 .188
12 1504 .02 5.34 1058 81 n 1.55 8.0 .194
13 1490 4.86 77 n 5 .00
14 1498 5.02 78 ii 4.96
Crja rakteristic curves of aBuffalo Forge Co's Volume Blower.
Tip speed of blaes uooo ft per mm.
Eng. HP
_ Efficiency
\Biast HPTotal Pressure
- Static Pressure.
to
2*
22
20
18
[6
ti
12
to
8
tOQQ ZO00 dOOO fOOO J0O0 6000 7000 80OO\90OO /0O#O M600EUGENE DICTZGEN CO., CHICAGO
2
90
80
70
60
60
fO
30
20
/0
ol ume m cu. ft. per mm.
oCO.
<b
CO
<i)
9
8
7
6
5
1
3
2
XI
o
4
39
DATA & RESULTS FOR TIP SPEED OP lOOOO FT. PER MIN.
No.R.
P.M.Vel.Head
Stat.Head Volume Temp
.
Bar.BlastH.P.
Ens.H.P. Eff
.
1 1360 1 . 12 7919 79 29.3 2 . 43 15. .164
2 1368 1.13 7954 78 it 2.44 15.4 .158
3 1355 .82 .928 6776 80 „ 3 . 23 13.28 .244
4 1356 .82 .934 6776 78 3.23 13.5 .240
5 1365 .53 2.32 5447 80 4.23 13.0 .326
6 1363 .53 2.32 5447 80 ii 4 . 23 12.6 .336
7 1365 . 30 .5 . 296 4u y y oU 4.01 11.1 .360
8 1366 .30 3 . 248 4099 80 4.01 11.1 .360
9 1365 .12 4 .048 2592 82 2.94 8 .
6
.342
10 1360 .12 4.080 2592 83 2.97 8.5 .35
11 1368 .01 4.656 748 85 .95 2 7.4 .129
12 1372 .01 4.608 748 85 .921 7. .132
13 1370 4.288 85 4.6
14 1368 4.288 85 4.3
ume in cu.ft per mm
DATA & RESULTS FOR TIP SP'iEJ) OF 9000 FT. PER MIN.
No.R.
P.M.Vel
.
HeadStat
.
Head volume Temp
.
BarBlast
. H.P.Eng.H.P. Eff
.
1 1226 .90 7123 81 29.1 1.75 11.4 .153
2 1223 .96 7123 80 n 1.75 11.3 .155
5 1228 .64 .832 6007 81 it 2.41 9.88 .244
4 1228 .61 .800 5864 81 ti 2.25 9.68 .235
5 1230 .40 1.840 4749 81 it 2.90 9.24 .314
6 1230 .40 1.872 4749 81 N 2.90 9.16 .315
7 1227 .24 2 . 704 3678 81 II 2.95 7.6 .388
8 1230 .23 2.704 3601 80.5 il 2.88 7.76 .371
y 1220 .09 3.328 2252 81 II 2 . 10 6 .38 .33
10 3.225 .68 3.328 2124 81 II 1.97 6.9 .286
11 1230 ? 3.632 81 »l 4.8
12 1219 ? 3 .520 81 II 4.6
13 1237 3.568 81 II 3.46
14 1230 3.552 82 n 3.8
Lharacieristic curves of a
Buffalo Forge Co's Volume Bfower.
Tip ftpeeq of nJarfe f voqo ft.\per min-
im
m
Pressure.
Efficiency
K
v.
20
18
16
ft
12
10
8
3D
80
70
60
50
10
30
30
10
SO
CO
5s
9
8
7
6
5
f
3
2
olume in cuff, of air per rn i n.
43
DATA & RESULTS FOR TIP SPEED OF 8000 FT. PER MIN.
R. Vel.
.
Stat. Blast Eng.Jr . — * Head Head Volume Temp
.
l)tXT • H.P. H.P. JtliX 1 .
J. .73 6325 64 99 ^ 1.26 8.1 1 RA• JL O O
o 1 D 94. .72 6282 64 If 1.23 8.12 1 5 9
1 n 9 P .52 .688 5339 63 tt 1.61 7.3 99
A*± .54 .688 5441 63 II 1.82 7.4 246
1 H9 R .34 1.452 4307 63 II 2.10 7.2 999
f. 1100 .34 1.452 4307 62.5 II 2.10 6.7 314
7 1090 .20 2.24 2951 62 II 1.95 7.1 .275
1 097 90 9 90ft fj J \J J_ ATO JLII 1 94 4 304
9 1089 .08 2.752 2094 61.5 II 1.61 4.6 .35
10 1089 .08 2 . 864 2094 61 II 1.68 4.75 .354
11 1090 .02 2.992 1047 61 II .86 3.62 .238
12 1090 .02 2.992 1047 61 tl .86 3.6 .24
13 1086 2.784 61 II 2.5 6
14 1087 ii.768 61 II 2 .
5
Buffalo Forge Co's Volume Blower,
lip speed of bfades eoooft. per min.
v.
S 20
SO
CO
o
7000 3000 3000 10000 11000
30
70
60
50
to
30
20
/0
16
It
II
JO
8
6
7
f
2
S
f
3
2
/
fS
EUGENE DIETZGEN CO., CHICAGO.
46
Discussion of the principles involved in the working
of Centrifugal fans.
In operation a centrifugal fan sets the air between its
blades revolving about its axis. In consequence of this motion
the air has imparted to it a certain amount of energy. The air
leaves the blades approximately tangent.tally to the circumference
of the wheel and with a certain velocity which depends upon the
velocity of the tips of the blades. The air after leaving the
blades will retain the energy thus imparted to it, in a kinetic
form, if the discharge is free, but if the discharge is restricted
then part of this energy will be used in compressing the air and
thus assumes a potential form.
The action of the fan upon the air should be the same as a
centrifugal pump, that is:- the air should be drawn in without
shock and should leave the blades with a velocity equal to the
tip speed.
In order to accomplish this the air should have its velocity
gradually increased as it approaches the inlet. At the Inlet no
sudden change of volume or direction of flow should occur. The
blades should slope backwards so as to gradually impart the rotary
motion to the air, and the tips should be radical so as to give
the air the full centrifugal force due to their tip speed. The
casing should be of a spiral form.
Such a fan is never constructed, as too much expense would be
involved
.
The capacity of fans, expressed in cubic feet per minute, is
equal to the cube of the diameter of the fan-wheel in feet multi-
plied by the number of revolutions and by one of the following
constants
:
For a fan with single inlet and delivering the air without
pressure #<6, when delivering air with pressure of 1 inch of water
.5_. For fans with double in lets the constants should be in-
creased by 50 per cent. (Prof. R. C. Carpenter)
.
The horse power required is equal to the fifth power of
diameter in feet, multiplied by the number of revolutions per
second, divided by 1,000,000 and multiplied by one of the follow-
ing constants: free delivery- 30, delivery against one ounce
pressure 20, delivery against two ounces 10. (R. C. Carpenter.)
4&
The following references are thought to contain the best
information upon this subject.
621.623 Efficiency of fans and blowers.
A. S. C. E.
Vol. 7. Experiments by W. T. Trowbridge and Geo. A. Souter
also to determine the volume of air delivered under
E. N. various conditions and the power required.
Dec, 11, '96.
621.623
Lon., Eng. Testing of fans and blowers.
July 24, '85.Prof. R. . Smith.
To find (1) how much wo>-k is required to be done
by a proposed fan (2) how much mechanical work is
done by a fan in place.
621 .623
P. I. 0. E. Oh the conditions and limits which govern the
30:276 proportions of rotary blowers.
Robert Briggs.
Year • 70 . (63 >. 5 d)
Gives opinions of various authorities and conclu-
sions. Good explanation of working of fan.
49
621.623
*
P. I. C . E. The design and testing of various types of centri-
123:27:3 fugal fans.
H. Heenan 8c W f Gilbert.
Dec. » 95. (55p. 31)
Gives results of elaborate experiments on the
efficiency of fans and deduces characteristics
curves that nay be employed in the design of a fan
with maximum efficiency for a given duty.
621 .623 Centrifugal fans.
Amer. Inst. R. Van A. Norris
.
"in. Eng.
20 : 637
Year' 92. Twenty-nine tests of nine ventilating fans:
tabulated data and results: discussions.
621 . 623 Investigation of a blowing fan.
E. R. Prof. R. C. Carpenter.
39:310
Elaborate test conducted at Cornell University.
Numerous curves of working of fans with different
shaped blades.
621 .623
H . & V . Same as above
.
IX : 2 : 7
Feb., '99
Theory of centrifugal fans, or rotary blowers.
Prof. R. C. Carpenter.
Deduces a theory. (Hves theoretical formulae for
the volume and horse power required. A simpleJj
practical formulae for volume, also one for horse
power required.
Methods of testing blowing fans.
Prof. R. C. Carpenter.
Gives descriptions of numerous methods of measur-
ing pressures. Opinions of each method. Cuts of
different gauges.
Efficiency of fans and blowers.
An editorial in which a new formula for computing
the H. P. is given by Prof. Herschel. Discussion
by W. C. Nnwiji.
Experiments and experiences with blowers.
H. I . Snail.
57
Year '87. (22p. li, 5t)
lUves tables of experiments and aethods of taking
same. Metriod of piping. Two fans should never
discharge into same pipe.
621.623 .
P. I. C. E. Manometer and mechanical efficiency of fans.
66:271
Explains and discusses above. Gives formulae.
621.623
A. M. Power required to drive centrifugal fans.
19:1218
(2p. 2 i)
Dec. 31, '96. Results of tests by Interior Conduit & Insulation
Co., who furnished motor.
52
Size.
55fO_\
55_
S.PPM. 603 X f& 603&X5& 70_
4- X6 86
5X 7/2 /0d \
5/2x8/4 110'
6X9 1207 X/O/z/lOa x 12 /6Q9 xt/z/ox 512 x 6
30"
35"
ffl
-ML55"
SRP.M. 60"
3X1''A 6(L_
^Xb/f 70"
f X6 80i4/<lx6%9o"
SX7A /oo"
sJkxeft //o"
6*9 /Zo"
7X/0& /408X/2 /60"
Qjl4£/OXS/ZX6
C. S. Johi
52
Mechanical Engineering Dept. University of Illinois.
Steel Plate Fans.
Table of Speeds j Pressure in Ounces, Capacity in Cu. Ft of Air per Min. & Power Required.
Siz e.
WFeel Sg. inchesol Bid ST. 1 « fa Ounce 7r Ounce z
/8 Ounce Ounc e 5/e> Ounce % Ounce / Ounce i/f Ounces.
Diet. Width. nwRev. Cu Ft. HP Rev. Cu.Ft HP. Rev. Cu.Ft. HP Rev Cu.Ft HP
\
ReF Co Ft HP Fev\ Co. Ft. HP Rev\ Cu.Ft\
HP Rev. Cu. Ft. -d.RInlet WM In/el
wOutlet 3 2
30 /2k 16 8fr 6 36 54 17' 38 9 .0254 v / .000 O ' 7 7 Q * ICC. 777 2/5- 967 060 fO c. U A7 V5Z\ 1 /Zo .344 7700 12 90 .53 1 230 7440 7435 14 21 ?7z 67a 48 72.2 5-1' 359 610 0313 50 7 86 Z 088 6Z £ 7n AT *7/Oof ./Sc- 7/6 IZZO .25 800 7360 . 35 878 1490 .46 70/5
8Z2/7 Z 5
1
2Z60.705
927
1140 1 /920 9940I Is lb 24 1/ 7% 6 3 94 6 /)O.D Z9I r\ n .041 4/0 // J O .//35 50 3 / O ot 2.CJ O 5ro /60 .328 648 7790 95S 7/4 I960 .603 12% 2520 1-293
T~> 18 27 /zti 9/z Pi T V /pa 7-7' 258 108 5 .0556 364 75 30 .1560 4 7 6 /b°8 .288 517 Z/do 474 575 2430 .62 634 2660 .816 73 Z1
30 70 726 920 3420 7.76
TV? 21 30 ISjk 70/, lO 2 5 1^4/ *S ' 7 85 233 1 300 X>667 329 78 1~0 .188 403 2260 347 46 5\ 26IO .533 5ZO 2920 745 570 3/90 980 660 1 36 90 7.5/ 738 4/ZO 2-1/
OJ 22\
33 15% 71% lei 9 1 94 O.p 213 762 .08 4- 300 23 20 .23/ 368 2840 .437 424 3280 ,6 7Z 366O .948 521 40 2 1.23 60 z 46 40 /. 90 674 5/90 2-66
Q PP M An 24 36 /67s 727* 74 8 223 /i
'
j r 795 18 80 J0965
J/8
275275
26603200
.272
.353
367
285
326039Z05150
.502.
.670
.792
389
389
333
3760 .772
.94Z
722
434
43f372
420050606650
1. 08
7231
7.70
177477
407
46/055407280
7J2L212-24
2.86
3889646.1
551 5320 2/8 677 5930 z.06
3 X f/Z ou 27%\ 36 76%79%
/5/a 181-5 273 J. 7* 195 2260 15205940
551!
470
914
3673303ai
64O0842070 800747007740022900
Z673-45
4515.98
7/394
A/752 i
46441/
369337
7760 3.74~z JA v £r// *73/^X5/4- VO4 X6 lid.
3/ 42 16% 234 352 //. 766 2 980 .152 235 42OO .43 94/012030/6400
4 236.78
17.32
36 4854
22/z /8% 300108 54-86
638
4 506/0728957
12.5
J4./
15.7'
17.2'
7I6Z730
38/051 8060708/00
.195
26 4
.315
.4/4
2o7783765
5380 55~ 2 54 6600897070700
U7J_13.17.61
293 76 2 7.56
2.12
Z5Z3.32
326
289260237
85307/5507380078 1'OO
2/82 953.5 2
4.64
358,318
285260
934072 700
757OO79800
?fkX oft 90 38 2b 22% 7330372jo
.745 2.25 260233
/035Q7Z3QO762QQ
c~ y 'jfo innD A //Z /UU 42 60 30 7/6
706
.883 2.0Z, 79500256 OO
n a tj
9.97-
Q/2A 0/4- I / U 47 66 34% 29 750 /74 50 7/7 784 74050 2./
5
2/3 1 1 /
a, y o ion 52. 72 407z 65/4 846 1270 18.8' 97 10750 .555 1375 75200 J.56 764 786 00 288 195 2.750
O
4.40 24000 6.Z 238 26300 806 27i' 304OO jZ4i 3og 33900 7n st
/ A / U/2. J TU 60 8 4 15% 10/4 112 7 1700 2 2.' 8 5 /4400 . 736 1175 2./12 00 2-06 /47 25000 3.3 2 76 7 Z86OO 5.88
6.47
8.6
785763744
322003550045ZOO
8.139.05
7/6
204-
J79158
3/50O3890049400
7d.811.9
75.3
2352o7783
40500450005 775-0
16.7
/S.3
23.5
25423Z206
45* "0
5'07 00_6?>7O0
02 a
O A Id. / OU 68 16 *5% 3 9 125 /a 70 25/ 73 15 900 .81 /a 3. 224Q0 2.Z8 /27 2 7500 4.2/
5.4
74773Q
3/80040400
9 A~ /tr
9 X ffz /08 5/f/z ff/f 1590 2400 28.2' 65 20200 /04 9/6 292 OO 2.84 1/2 3 5000i A V £T/ U A O /20 57?f 50/f 2010 30 zo 3/4' 58 _ 250 / 31 82-3 36/00 3-68 /a7 ,
9430O 68 //7 51/00 /0.45 730 5 7/00 746 743 62600 79.Z 765' 77^00 29.0 785 Qdb'OO 4/4/ P X A/ <£- A O 144 69fz 59/a Z&bO 4280 37 4' 49 36300 18 5 69 5/300 5.23 8451 6300O 963 977 7Z700 /4.80 /0 9 8/300 208 l/%S 8 9000 27.Z 738 7a 3 000 420 75S 7/4 500 DO u
/k[ Ounce S 1% Ounce S. 2 Ounces lOunce^ 3 Ounc es. f Ounces. 5 Oc/nces. 6 Oo/ices. 7Ounces. 3 dt/nce^
JO 736'0 ,580 .974 /460 j7/a
2Z807227.64
d-15
290
7560
/4407/70
/038
/8402450
/5201
263356
7745/6/0
JMl7/6/
20402720
Z.I
2.8
19/01765144012807/50105096396 3
8257236425785254804/2
361
224029803960537Q6f50
8/209/90
11 100/460O787002570030500
3 9700
532007320070900
27637414658
7.87
9.9Z
ri.4
13.9
180Z3.0
31. Z
27.Z
49.0
65.5
87.0
956
ZZZO
Z050
/660
261034804560
427
747105^12/75377J^2/-5
Z7.8
35.5
482574756
707.0
73407475
24902290
/86O
J65Z/990
29/03S80509069208320
5.97
798/OS
i7.e
2/424.6
30.Z
38-9
Z12025IO
Z01Z
18/6
1636
7490
/36Z
I16Z
ItS 5
3260427056 OO76Z0
9/40
11500
7320015800208OO
7.85
/0.5
73-8
7852142dZ3Z439.6
51 Z
2950Z7Z0
ZZOO
I960
1770
1610
7475
74757260
34704620607082309900124007430017ZOO22600
9.94
13-3
12J_23628 3
35.7
410
\993_'64 8
1 528712.0
/340176
236.1
3I3C344.C
3/6o\ 3720 12.Z
35 /240 11 IO 7.31 7540 29202360
J 950 7634/)'' 70/0 2770 /.IFMM
976'
300040 70
32/Q4 370
3 5 90 \ 3.67 6500 21.3
45"- S97 3760 2\3J_ 4A7P 4.97 /476
/330
/Z/0
1110
1110
948835740
664
607554474
4/7
6/8Q74309330
IO7O0
I2.90O
769002/700
29600
35Z0O46ZOO61ZOO8/5009O500
2090
/890
/7361580
8830 Z8-3
50" S08 4520 2J6-X.50
274
796
48 70
6/503J9_440
935849
52306570
4Z8 7/745 58307370
5.97
7.53
/0600 crt- /
55 737 /35Z I /0440 _13500 43.7
o.nr.M. ou 675 652 n 4.02
1. 91
6.35
8-12
7/0
73.72
172522 9
30.6
337
729
72962351818/
7030
Fd160///OO74 3 OO/9500
5.07
6/9798/0.2
73.8
782
782668
75509080
// 900
6.Z
7.60
9.7&
8738 73
747
8900jo/00/3300
8. 6570. 557377
/Z40
/240
/06O
/200O
J4400/890O
15300 50.Z
3X4'/z 6o" 675 M'40
00oooo
1580
/350/1 90
1050
997864
r 790675594
18300 603
3&XS& 70" 577 /OA24ZOO30900
79. Z
/o/.o4 X6 80" 5G6 732 587510
168427
390334294
/530O20800248003260 0, _
432005750063700
12577.
20.2
26.6
35.3
47.3
62.0
656582522477436
373328
1 7000
_233002 76OO3620048000613007/30070300
7 7.5
236l28237-Z
19 3
66072.6
93.1
7/7.0
766.0
935830
744
680
62/
53Z467
2430033000392005/500
683009/300
/O/OOO
49867.3
80.5
706.
/4I.5
/88.0
207.
10109/e
2670036400
65.5
88-8
706.
73 9.
786
247Z7Z
7//0
985878807737
63/555
289004020046800^6/500
81500
/09000/20500
47?.x67*9o" 450 7843000 I1L_
^5L*7fz /od5/zX8% //o"
404369
2/40O28/00
<
572004-970055000
43 7
_398364
3IZ274
23/0030 3 OO
76S2/7
8/4 43300 50200 /64
74 Z 56800 658008730077700072 9
2/6
2883834ZI
6x9 /Zo" 338288254
40200 ,28.8
53800 \38.6
59400 42.4
68Z5/3454
7530O
7OO 300
7/1 000_7X/o7i 1408X/2 76o"
9X4%. 225 70200 43.3 243 75900O^Tnn
ft*68.5
77 6
JLAO^
231796
81loo 66.7 29/ 52/
2 88240
J)98POI26Z00178 000
IA30^
154.0
ZZO.o
537
Q
33Z278
11500074350O
moZ36.0
j414372
/28500
/63 500266.
334.
45440834Z
742000
179000254000
349440
623
49Z44Z370
/53000,
I93100_276000
±t—- m
442. 527 764000 540
10X5/2.X6
202/69
885QQI26OO0
515774
9 IS 702500/46 000
89.
7/9,0
261
218
7/400(5
762 00
556788
973 207000 680
7351 736000 207000 338.0 3/Z 2.32000 4 73. 396 29500L» 965
V. V. \7Vhee7
* ? Diarnefe/ 1
Inlet
8/4 i
o 9%7
2
4%7
/0/S 3
12/4 4
71% 33 8%f 70 77/z t
5 //h 20 ;
6 /t/z7 76 27 j
8 /S 37 7
9 2/ 40 A
70 2f 46 :
3 Ounce2/o 4200 2
5S607 3780 3~
2 2840 8
3 2360 //!
+ J980 7Si
5 7740 20
6 7475 367 1290 52
8 1120 77i
9 865- 77 7i
70 75~6 76/
c
80uncz/o 688
O
3.
5820 6
7 5220 St
2 4640 73*
3 3870 79i
4 3266 2/"t
5 2850 34'
6 2430 60i
7 2020 668 /860 1179 7420 19370 7240 265
Horse
C. S. John
Mechanical Engineering Dept University of IllinoisTable of Speedsj Pressure /n Ounces, Capacity in Cubic Feet per min. & Power Fiequi red.
1>
Whee/ S q
.
'n. of
st:DW+2
3=
<o >
^ Ounce. / Ounce. //z Ounces. 2 Ounces. 2 /2 Ounces.Diameter VV id. th
Inter Wfieei Jtt/et Oot/eT
B la
3 Rev. Cl/.Ft 7/.F Her-. Co*. Ft. 77.P. He 17. Co. Ft. H.F. Re v. Cu. Ft. H.P. Rev. Cu. Ft. H.P
7
T //Q u/4 2 //i7 fa./ '4 3-44 5.76 2./
6
7695 8 73 .0/7S 24002050
724234
.0504
.0955
2940 757 .707 3400
28802530
17533/475
/ 4 3
.2 71
.389
3800oliO
2880
79536 9
52 8
200
.37£
.593
5 //6O 3/.
At , 22 9/,,^ 7/6
6-5
9.329-75 2 '.55
2'.85
7435 76 5 0357 2490 286 J7/78 /U/S 3/t6 74.0 /285 237 ,0484 1820 336 13 7 2230 4/0 .29/
2 7/ I<z74
74%
4 77o7/2
5%O 7/6 13.5 20.3 320 //40 34 3 .0 70 1620 48 5 .199 7980 594 .422 2290 668 .564 2560 JL6 7 .787
54
.
567'
89
JO
TPS 19.0 2.8.
6
3-85
4'.57
950800
48 3 ^019^135
1350
1130
68 3
943.280
.586
7650
/3908 35
7/60595.8 2
/9/0
/60
96 7
/ 3 40
769029 90
7957-70
7-39
245
2/30
/790
1570
1550
/080 /•//
/O 77/z 6% f/2. 26.3 39 4 667 /490/88O33 30
/'53
/.9f
3.42.
7//f 20 7/z
d/8s7/29/4
33.25~8.7
So.o88.2
5-226'.74
700595
843.1490
.773
.305
994842
7/902//0
.490
.865
7 22
/220
/030
902
_7462.580__
3670
7 047 8 4
2.6
14/0
1/90/f/z 23/
76 27 //i 83.3 /2 5. 703 520 27 16 .432 736 2990 1040 4250 3.48 f/60 47 30 485/6 37 77 113.7 /70.5 8'/0 452
348ZR90 .590 640 4080 7.67 684 5000 3.54 907
700
58 10953
4- 757.78
JO/0
780
64 40/0 6OO
6 60
70.92/ 40 74 187. 280. /0.5 A750 .97 493 67 2o 2.74 _604_ 8230 5822f 46 20 76
5/4 257. 386. J2.0 305 6 540 7 35 432 92 50 3.78 530 // 300 8 03 612 /3/ OO 70. 7 684 74-60 75.
3 Ounces. 3^2 Ounces. 4 Ounces. 4/2. Ounces. 5Ounce s. 6 Ounces. 7 Oun ce s.
2/o 4200 215 .264 4480 23/ .3 5 482o 250 .407 5070 2 62 .454 5400 2 79 565 5930 50 6 .75 6440 332 .95
55S0 407 598 3790 437 .625 4080 470 .77 4300 495 .861 4530 52 7 7 08 5030 580 7 42 5450 626 1.79
/ 3/8o 3~8 3 .776 3590 627 .897 366 o 676 /./O 3840 7/0 1.2 4 4-/00 755 /55 4500 352 204 48 80 897 2.58
2
J4
2840 84 5 /.04 30 to 906 73 3260 977 7.6 3420 103O 1 78 3650 /0 95 2.24 4000 /200 2,96 4350 /300 3.74
2360 J/90 746 2,510 7230 783 2770 7375 2.Z6 2800 /450 253 3030 7540 516 3320 /6 9 4.77 3620 /8 30 5.45
1980 7640 2.02 2.110 /770 252 .2280
Zooo
79oo 3.11 2400 200O2530
348452.
2560 2/30 435 2800 2540 573 3O40 2530 7.25
56
/7fO 2080 2.56 7850 2250 3.2 Z4/o 3.94 2100 2240 2700 553 2450 2 970 7.28 2600 3200 9.20
7475 3670 4-5 /570 3940 5.65 1700 4250 6.95 1780 4470 780 J900 4760 9-75 2080 5220 12.8 2260 5650 7627 1290 5200 6.4 /380 56 OO 8.0 7490 603O 9.37 /560 6350 J/.C /66O 6750 138 1820 74 20 78.2 /980 8030 25.0
39
/<?
1120 77OO 8-73 72O0 7620 /0.9 l29o 625o 73 45 /350 8640 /5. 7460 9220 /8.8 16 00 JO/ 20 255 /740 /0 90O 3/4865 J7 700 /4.3 920 /2600 17.8 995 /55vo 22/0 (OfO 74200 24.8 ///o 75200 3/0 12Z0 76700 40.8 /520 78000 5/.S
75~6 76JOO /9.8 806 17300 24.7 870 7860O 33 5 9/2 /9600 341 875 20800 42.7 106 5 2290O 562 //60 24800 7/0
8 Ounces. 9 Ounces. 70 Ounces. 1/ Ounces. 72 Ounces /3 Ounces. /4 Ounces.z/o 63SO 355 1/6 7325 377 /. 39 7680 398 763 81oo
]
4 19 788 8470 437 2.15 8850 458 2.41 92ZO 475 2.73
/
5820 670 2/9 6200 7/3 2.62 6520 752 3.63 6870 79/ 3.56 7180 826 4.07 7500 865 4.60 7620 8 98 5.15
5220 960 3.15 5550
4950
/0 20 3.77 5530 /OdO 443 6/40 1130 512 6430 // 85 5.83 67/0 J 240 658 7000 /2 90 757
2 4640 /390 4.57 7460 545 5/80 /56 6 642 5470 /6 40 740 5720 1720 85 7 5970 J800 9.55 6ZZC /86O /0.7
3 3870 /960 6.45 4120 2080 770 43Z0 2200 9.04 4550 23/0 7043 4760 2420 J/9 4960 2350 J3.S 5170 2620 151
4 3260 2/70 8.88 3460 2880 70.6 3640 3050 12.45 3830 3200 74.4 4010 3340 /6.4 4/80 3500 16-6 4570 36 30 20.8
5 2850 3440 11.25 3030 3650 /3.4 5/80 3860 /58 3360 4050 78.25 3510 4230 20.8 3660 4430 23.6 38 ZO 4600 26.4
67
2430 6050 19.80 2560 6440 23.7 27/0 68 00 27.9 2860 7740 32.2 2990 7450 36.7 3/20 7800 4/.
6
3240 8/60 46.6
2020 660O 282. 2250 9/50 337 2360 96/0 39.5 2490 /0/3O 456 2600 70600 52.1 2726 1 / 1 /OO 59.0 283C 1 //500 658
8 /860 11720 38.4 1980 /Z5-00 46- 2050 /3/ 50 53.8 2/60 I380Q 62.2- 2260 74400 770 2360 J5J0O 80.2 2460 258 OO 898
9 /4Z0 I93O0 63.0 J'500 20500 75/9 /580 Z/600 88.5 /670 2280 /0 2.0 1740 23800 117.0 7820 2450 I32.C ' 18 90 256 748-0
to 12.40 26 50 87.0 1320 28 ZOO 7J4.0 7380 29800 /2Z-.0 1460 3/30 74/.0 1525 326QO 16/. /530 39ZOO /62.0 /660 35500 20AO
Ho r 5e Power Co IculatecL at ^-) w2. IOu.Fr. ca IculaTed at ^ fD- diameter of yvnee/ & W- wieft/t at ci rcum.J
_ _ ^ ec. m _ at 5~
C. S. Johnson (Thesis) T̂ Je <*s compiled b r 3.F. Sturtevaat for 'Monogram 0fo*erS
1 i mm * * iit*--'-* * 4 *
* * § | # m 44 * * 4 * 4
'
*m *'* i§i nil * * *
,
* *. i i
* 4 4 - 4 4-4,4,4^-***4 4 4-*'*- * 4'- 4 * * I * 1 1 1
i I f * 11 * * 1 1 1 1 * + * |I * §M * * * - * * * I tetel *
+ * + + *4* + * + * + 4* +
+ * * +t§|l m * * *AI////'7
Ufa
i i I I I i I I I * i 1 i * iI I * I n i * * i
* 4- 4 ,4 1 # *' *% * 4
§ ' § ' 4. 4 I§ * * * | I
~ W, ^ ^ '
~^ Hp it
ip i IlK^P^B * * * * * * 1 1III I ! * .4 I • I * 4 4 I I * * |i I n * i * i * * * * * * * il 4 ^ , i * 4 4 i | i
* -4 *S% Hill 4 * I * lit *
i i i i.4
-* 4 *
. t Ml* j§S 4 4 I ,4 #j 4 4 * I * * ****************%**4 4*4*^*** + * *
4 4 4 4 4 I • 4- 4 .4 * * * * * 4| | i 4 I | I .4 * * * - § -* 4
4'* 4 * * * 4 4 § * f f * * *
-4 If I I ;4-:4 4,4 4, *>".. 4 4 *|j* ' 4 . 4 * § 4
,
* 4 * * I * * * *
* * I 4 4 4 ' * * * * 4 * * * *. 4 -4 * : 4 -.-4-^;* - -4 -
. 4 I - I • I § + ;
.-+<-. *
& -; 4-
^ i §
^ * *
|| ||.
*
i § 1 |* |
^ Ik 4-
|| * I |*. * H
* H Iter?
|| II ||
I I §
|e <jj
* * *