Aug- 5, 1952
J.‘M. PEARSON
'
2,605,638
FLOWMETER
Filed April 15, 1946
31
AMPLlFIER
20
23
IN VEN TOR.
Patented Aug. 5, 1952
2,605,638
‘
] UNITED; srarss PATENT; orrics
FLOWMETER
John-M. Pearson,’ Swarthmore, Pa., assignor to
‘
S-un Oil Company, Philadelphia, Par, a corpo-a
ration of New Jersey
Application April 13, 1946, Serial No. 661,943
2 Claims. (Cl. 'i'3——228)
.
1
1
.
The present invention relates to the measure
ment of ?uid ?ow.
, v
2
I
.
,
‘
pensated by static-pressure difference. Thus, the
upward reaction produced in the cups is: about
one half compensated for by Bernouilli effect,
_
An object of the invention is to provide a device
for measuring ?uid flow, which is independent
of the nature of the ?ow, by observing the mo
mentum per second of the ?uid which passes ‘a
given point in a conduit. Thus, an object of the
invention is the provision of a device which is
operative with excellent accuracy'to measure fluid
The reaction on the cups varies as the square-of
the?ow rate timesifthe density of the ?uidp "Y
Means for the measurement of the-reaction or
change of momentum as a measurement or indi
cation of the rate of ?uid'?ow. is'illustrated.
Thus cups ‘l3 and‘ [3' are mountedon arm (It)
hinged or linked at I’! in such’ manner that arm
(Hi) will move vertically without deviating'from
the horizontal. At the other extremity‘oi arm
(it) there is a push pull carbon pile I8; or its
flow whether or not said ?ow is streamline or
turbulent. Further, it is anlobject of the inven~
tion to provide a device for ‘?uid ?ow measure~
ment which is independent of the viscosity of the
?uid the flow of which is to be measured.
According to the invention, use is made of the
equivalent, fed by shielded transformer 19. As
the arm (it) tends to move up and down,'about
hinge or link H, a signal proportional to the
reaction on pile I8 is fed to linear ampli?er 20
which produces A. C. current in solenoid 2|, am
to produce a reaction upon provided measuring
meter 22, amperehour meter recti?er 23 and
means hereinafter described and claimed.
24, all in series. Solenoid 2| produces
According to the invention there is provided 20 armature
a flux in gap 25 producing a pull on armature 26
a device for the measurement of fluid ?ow which
proportional to the square of the current I, indi
operates upon a ?uid to cause a change in its
cated at ammeter 22, tending to restore arm (Hi)
momentum and measuring the change in momen
to its original position. Because of the square
tum thus produced.
‘ '
law
the current required in coil 2| is proportional
Otherwise stated, there is provided, according
directly to the ?uid ?ow rate and the current
to the invention, a device for the measurement of
?owing at any time is an indication or measure
momentum of a ?owing fluid to measure its rate
of ?ow by causing a change in said momentum
?uid ?ow which comprises means to divert a
7 of the rate of ?uid ?ow.
?owing ?uid from its path of ?ow and measure
the change in its momentum. Still, otherwise
stated, the apparatus of the invention comprises
means to divert a ?owing ?uid from‘ its path of
flow and cause the change of momentum of the
through the apparatus. ‘ Ammeter 22 may be cali
brated to give directly the rate of ?ow. A zero
?uid thus produced to actuate means adapted to .
adjustment is provided by spring 30 and adjust
measure or indicate the extent of said change.
As shown in the drawing, which is a crossf .
sectional elevation of the device embodied in the
invention, a ?owing ?uid fed through conduit [2
is discharged into cup l3 and thence into pres
sure vessel [4. The ?uid then enters cup l3’
?nally leaving the apparatus through conduit Hi.
ing screw 3!. Enclosure of reaction cups I3 and‘
:3’ in pressure vessel l4 and symmetrical dis
posal of inlet and outlets reduces static pressure
and friction errors.
40
The sizes of cups I3 and it’ can be such that
the momentum of the ?uid entering into each
cup, respectively, will equal the momentum of the
?uid leaving each cup. The reversal of momen~
tum produced in cups [3 and 13' produces a re
action tending to displace said cups in an up
wardly direction. This reaction is only partially
balanced by the force caused by the difference in
‘static pressure between the inside and outside of
13' which arises by reason of
the Bernoulli effect. The additional force neces
' the cups l3 and
sary will be supplied by the solenoid 25 as will be ,
described below. If the cross sectional area of the _
pressure vessel M is very large the upward re
action of the cups will be only about half com
Amperehour meter
armature 24 in permanent ?eld 21 rotates at
speed proportional to current, by means of damping disc 28, causing register 29 to integrate ?ow
As used herein and in the appended claims,
the term “fluid” includes gases, vapors, liquids
and all other substances having the properties
of ?owing ?uids.
'
From the foregoing description it is obvious
that the measurement of flow is accomplished by
a measurement of momentum change, or the re
sulting reaction, as distinguished from metering ' a
of volumes (displacement meters) and metering
of energy change (‘Venturi meters) based on the
energy of the stream in accordance with
Bernouilli’s theorem.
'
It will be obvious to those skilled in the art
that the ?ow meter can be provided with a ‘by
pass pipe so that only a portion of the ?uid, the
?ow of which is to be measured, will pass there
through. However, it is to be noted that the
2,605,638
3
entire ?uid passing through the operative por
tion, tube, cup or other equivalent means, of
the ?owmeter is acted on to cause a change in
4
?uid through said housing, an arm supporting
said cups in spaced relation, a parallel linkage
coupling one endpof said arm to the interior of
said housing to maintain the cups in a hori
its momentum and that this is the change of
momentum measured.
m zontal position under all ?ow conditions, elec
I claim:
trically operated means to measure the ?uid ?ow
1. A device for measuring the rate of ?uid
flow in‘ a conduit comprising in combination a
in terms of the deflection of said cups including
a movable resistance current control in operating
sealed housing adapted to contain a Volume of
engagement with the supporting arm, an ampli
the ?uid to be measured, a ?ow de?ecting surface 10 ?er coupled to said resistance, a restoring sole
within said housing including a pair of adjacent
noid mechanically attached to said arm and elec
inverted cups, means providing a passage for
trically coupled to said ampli?er, a meter in
?uid flow through said housing having an inlet
series with said solenoid to indicate instantaneous
positioned to direct ?uid ?ow into one of ‘said
electrical demands, and a registering means in
cups and an outlet to direct the ?uid flow from
series with the ampli?er and said meter to total
the second cup, an arm supporting said cups in
the measured ?uid ?ow for determined periods.
spaced relation, a parallel linkage coupling one
JOHN M. PEARSON.
end of said arm to the interior of said hous
ing to maintain the cups in a horizontal position»
REFERENCES CITED
under all flow conditions, a variable electrical re 20
The following references are of record in the
sistance operated by the free end of said sup
?le of this patent:
port arm, a solenoid core attached to said sup
port arm, an electrical coil embracing said core,
UNITED STATES PATENTS
and electrical means to connect said variable re
Number
Name
Date
sistance and the solenoid coil whereby the quan 25
tity of electricity flowing through the solenoid
coil to restore equilibrium of the supporting arm
is a measure of the ?uid ?ow.
'
1,401,299
1,479,663
Wohlenberg ______ __ Dec. 27, 1921
Herz _____________ __ Jan. 1, 1924
1,581,957
Keller ___________ __ Apr. 20, 1926
Payne ____________ __ Apr. 3, 1934
1,953,819
2. A device for measuring the rate of ?uid ?ow
in a conduit comprising in combination a sealed 30 > 2,319,363
2,383,757
housing adapted to contain a volume of the ?uid
to be measured, a ?ow de?ecting surface Within
said housing including a pair of adjacent inverted
Number
cups, means providing a passage having an inlet
extending into one of said cups and an outlet 35
extending from the second cup for the ?ow of
Wunsch et al _____ __ May 18, 1943
Ziebolz __________ __ Aug. 28, 1945
FOREIGN PATENTS
Country
Date
215,355
Germany ________ __ Oct. 26, 1909
369,588
Great Britain ____ __ Mar. 21, 1932