Note: Descriptions are shown in the official language in which they were submitted.
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FOUR-WAY FLUID FLOW DIVERTER VALVE
U.S. PRIOR ART OF INTEREST
Coyne 644,2~0 Feb, 27, 1900 (Issued)
Boland 1,95S,262 May. 8, 1934 (Issued)
Peacock2,296,568 Sep. 22, 1942 IIssued)
Heeren e~ al.3,319,710 May. 16, 1967 (Issued)
Cleaver et al.3,373,592 ~ug. 10, 1976 (Issuedl
Tomlin et al.4,286,~25 Sep. 1, 1981 ~Issued)
BACKGROUND AND SUMMARY OF TH~ INVE~TION
This invention relates to an improved fluid
flow diverter valvet which is adapted especially for use
in the cleaning of tubing of heat exchangers.
It has previously been suggested that heat
exchanger tubing may be internally cleaned by mounting
brush-basket assemblies on the ends of the tubes, and then
by flowing flui~ first in one direction and then the other
to cause the brushes to traverse the length of the tubes
and then return to their original position. See the
above-identified U.S. Patent Wo. 3,319,710.
It has also previously been suggested as in the
above-identified U.S. Patent 3,973,592 to utilize a four-
way valve for purposes of reversing fluid flow within the
tubes to cause the cleaning brushes to move in both
directions within the tubes.
It is also known to provide a valve with a
movable frusto-conical plug element or the like and wherein
the outer wall of the plug element is normally seated in
a frusto-conical seat, but wherein the said outer wall oE
the plug may be lifted from its seat and turned during
valve actuation. See, for example, the above-identified
U.S. Patent 4,286,625.
The present inventor is also aware o a recently
developed four-way diverter valve construction having a
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cylindrical housing wall and two pair of in-line ports for
connection to a heat exchanger condenser or the like.
Disposed within the interior of the valve housing is a
longitudinal hollow tubular fluid flow diverter element
mounted for rota~ion on a transverse axis coinciding with
the center axis of the cylindrical wall. The tubular
diverter element is provided wi~h an inner generally
diametrical baffle which forms separate but parallel ~luid
flow passages therein. Diametrically opposed longitudinally
e~tending radial ribs are disposed on the outer wall of
the tubular diverter element and directly in line with
the edges of the inner baffle. The end closure plates
for the valve are provided with a first stop device for
enga~ement by the diverter element ribs for properly
positioning the diverter element in a normal position
parallel to the in-line ports. A second stop means is
provided for rib engagement to properly position the
diverter element in rotated position when the fluid flow
downstream of the valve is to be reversed.
Although the end edges of the tubular diverter
element and the baffle have been machined to closely conform
in curvature with the inner curvature o~ the cylindrical
valve wall, and very close tolerances have been maintained
therebetween and with the positioning stops, problems have
arisen with the known valve.
When the tubular diverter element is in its
normal position, fluid flows through the valve housing in
a straight line between the upstream and downstream ports,
with one flo~ being reversed from the other. The baffle of
the tubular diverter element is intended to separate the
oppositely flowing fl~id. However, there is a ~luid pressure
drop between the supply and return side of the valve, and
leakage or bypassing of fluid from the supply side to the
return side has been ohserved, especially at the contacting
interfaces of compound curvature between the end edges of
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the tubular diverter baffle and the inside cylindrical valve
wall. Some bypass has also been observed in connection wi-th
the firs-t s-top means. The bypassing of fluid from -the supply
to the return side of the valve is highly undesirable because it
lowers the efficiency of operation of -the device downsteam of
the valve. Bypassing when the -tubular diverter element is in
its rotated position has also been observed.
In addi-tion, it has been observed that when the tubu-
lar diverter element is rotated between positions, -the end
edges of the elemen-t tend to bind on the inner surface of the
cylind~ical wall as the edges slide thereacross. Machining the
parts to less close -tolerances could alleviate this problem, but
the above-described bypassing would be undesirably increased
even ;nore.
The presen-t invention improves the fea-tures and opera-
tion of the above-described valve known to the inventor. The
present invention substantially decreases the bypassing of
fluid be-tween the supply and return sides of -the valve. The
present invention also subs-tantially reduces or eliminates the
problem of binding of the tubular diverter element to the
cylindrical housing wall during rota-tion of the diverter ele-
ment between positions. The presen-t inven-tion accomplishes all
of the above in an economical manner.
According to the presen-t invention there is provided
in a diverter valve for connection between a source of pres-
surized fluid and a process device, with said valve having: (a)
an enclosed housing having a generally cylindrical wall closed
by ends walls to form a cylindrical valve chamber, (b) a pair of
spaced adjacen-t upstream ports and a pair of downstream ports
with each upstream port being in-line with said downstream port,
(c) an elongated longi-tudinal hollow tubular fluid flow diverter
element disposed within said housing and with said diverter
element including a generally diame-trical baffle therewi-thin
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which forms a pair of separate parallel fluid flow passages,
said diverter element and baffle being of a leng-th approxima-t-
ing -the diame-ter of said cylindrical wall and having end edges,
(d) diamet.rically opposed longitudinally extendiny opposed rib
means disposed on the outer surface of said diverter element
and in-line and coextensive with said baffle, (e) means mount-
ing said diverter element for rotation between -two operative
positions about a transverse axis coinciding with -the center
axis of said cylindrical wall, (f) the first of said operative
positions providing for two reversed generally parall.el straight-
through supply and return fluid flows between in-line ups-tream
and downstream ports and through said chamber and said fluid
flow passages within said diverter element, (g) -the second of
said opera-tive positions providing for -two reversed crossing
lS supply and return fluid flows between diagonally opposed ports,
with one flow passing through said chamber and the other flow
passing through said pair of passages in said diverter element,
(h) selectively actuatable means for rotating said diverter
elemen-t on said transverse axis between said firs-t and second 20 ope.rative positions, (i) and stop means cooperatiny with said
rib means when said diver-ter element is at said firs-t operative
position (1) for positioniny said diverter elemen-t (2) and for
separa-tiny said valve chamber into two isolated portions (j) the
improvemen-t comprising cooperative means disposed on the interior of said
cylindrical wall and disposed on said end edges of said diver-
ter element for reducing of bypassing fluid flow within said
valve, said cooperative means on the interior of said cylin-
drical wall. comprising: (1) sea-ts mounted -to said wall be-tween
said upstream and downstream ports and intersected by a central
longitudinal plane containing said baffle when said element
is in its said first operative position, (2) said seats extend-
ing in one direction circumferentially toward and surrounding
a pair of diagonally opposed ports of said upstream and down-
stream ports, and extending in the other direction circum-
ferentially and terminating on the side of said plane remotefrom said diagonally opposed ports, (3) said seats having
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concave faces which, in sec-tion, are inclined planularly a-t an
acute angle to said transverse axis and the inner surface
of said cylindrical wall.
Thus, in accordance with the invention, diagonally
opposed ports in the valve housing are surrounded by concave
seats which are inclined at an acute angle to the cylindrical
housing wall and the axis of ro-tation of the tubular diverter
element. The end edges of the diverter element wall and baffle
ends are slanted -transversely a-t substantially the same angle
to p~ovide an engageable planular interface, insection, be-tween
the parts. Each seat extends circumferen-tially toward the
other adjacent port and is intersected by a central
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longi.tudinal plane containing the haffle of the tubular
diverler element when the element is in i-ts conical posi-
ti.on so that the seat terminates on the side of the diverter
element baffle remote from the surrounded port when the di-
verter element is in normal position.
An axle mounts the tubular diverter element for
rotati.on about its axis. A device is provicled -to shift the
axle axially when desired. Thus, the diverter element and
its associated parts can be tiyh-tened onto the seats, but
also when the diverter element i.s to be rotated from its
normal to its second posi.tion, the end edges of the associa-
ted parts can be lifted from the circumferential tapered
seats for free subsequent rotation.
Resilien-t seals are provided in associ.ati.on with
the longitudinal ribs and stops. The seal is main-tai.ned
during shifting of the diverter element along its axis.
BRIEF DESCRIPTION OF THE DRA~7INGS
The accompanying drawings illustrate the best mode
presently con-templated oE carrying out the invention.
:~n the drawing~:
Fig. 1 is a schematic showing of a heat exchange
system to which the fluid flow diverter of -the present in-
vention may be applied;
Fi.g. 2 is a perspective view of a ~alve construc-
ted in accordance with the concepts of the invention;
Fig. 3 is a vertical section taken on line 3-3 of
Fig. 2 and showing the diverter element in normal positiorl;
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Fig. 4 is a view similar to Fig. 3 and showing the
diverter element in fluid diverting position;
Fig. 5 is a vertical sec-tion taken on line 5-5 of
Fig. 2 wit:h the diverter element in normal position;
Fig. 6 is a horizontal sec-tion taken on line 6-6
of Fig. 2;
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FIGS. 7 and 8 are detailed horizontal sectional
views taken on their respective lines 7-7 and 8-8 of FIG.
5; and
FIGS. 9 and 10 are schematic views showing the
lift-and-turn positions of the diverter element in
somewh~at exaggerated form.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The fluid flow diverter valve 1 of the invention
is shown schematically in FIG. 1 and may be utilized in
connection with a process device such as a heat exchange
condenser 2 having a plurality of tubes 3 therein. Diverter
valve 1 normally supplies cooling water from a fluid source
4 such as a lake or the like and flow thereof is continuously
generated by a pump 5. The diverter is connected to pump
5 and source 4 through a suitable fluid supply line 6, and
also to source 4 by a suitable return line 7. A pair of
lines 8 and 9 connect diverter valve 1 to condenser 2 in
the conventional manner. Diverter valve 1 is actuatable
to reverse the flow in lines 8 and 9 so that tube cleaning
brus~es, not shown~ can shuttle back and forth in condenser
tubes 3 from time to time.
Turning now to FIGS. 2~6, valve 1 is shown as
having a housing including a cylindrical wall 10 closed
at one end by a wall or plate 11 secured thereto as by
welds 12, and closed at its other end by a wall or plate
13 secured thereto as by bolts 14. The construction forms
an internal cylindrical valve chamber 15.
Cylindrical wall 10 is provided with a pair of
spaced ports 16 and 17 which are upstream in the loop
formed with source 4 and condenser 2 (see FI~o 1 ) I and
always function as supply and re~urn ports respectively.
Similarly~ wall 10 includes a pair of spaced downstream
ports 18 and 19 connected to lines 8 and 9 to condenser 2. As
shown, the construction provides diametrically opposed
in-line pairs of ports.
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For purposes of diverting fluid flow through
valve ll an elongated longitudinal hollow tubular fluid
flow diverter element 20 is disposed within the valve
housing. Diverter element 20 is open-ended and includes a
5 cylindrical wall 21 and an inner generally diametrical
imperforate baffle 22 which forms a pair of separate parallel
fluid flow passages 23 and 24 therein.
Diverter element 20 is mounted for rotation
between operative positions about a transverse axis 25
coincidin~ with the center axis of cylindrical housing
wall lOo For this purpose, diverter element 20 is secured
to a pair of stub axles 26 and 27 which are journalled in
respective bearings 28 and 29 on respective plates ll and
13. A pinion 30 is disposed on an outer extension of stub
axle 27 and meshes with a rack 31 ~xtending from an actuator
32 having the usual motor 33 and gear box 34 connected to the
rack~ Selective actuation of motor 33 thus causes diverter
element 20 to rotate on axis 25 between a normal position
parallel to the in-line ports, as in FIGS. 3, 5 and 6, and a
rotated position, as in FIG. 4.
Referring especially to FIGS. 5, 7 and 8, stop
means are provided to locate diverter element 20 in its
normal position. For this purpose, diametrically opposed
longitudinally extending radial ribs 35 and 36 are disposed
on the outer surface of wall 21 of diverter element 20 and
directly in line with and coextensive with the edges o
ba~fle 22. Ribs 35 and 36 extend the full length of element
20 and are interrupted by the respective stub axles 26 and
27. An L-shaped elongated stop member 37 is disposed on
the inner wall of plate 11 and extends parallel to the
in-line ports and midway therebetween so that it intersects
axis 25. The upper portion of stop member 37 above axis
25, as shown in FIG. 5, is provided with a forwardly facing
resilient seal strip 38, while the lower portion of stop
member 37 below axis 25, as shown in FIG. 5, is provided
with an oppositely rearwardly facing resilient seal strip
39. Likewise, an L-shaped elongated stop member 40 is
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disposed on the inner wall of plate 13 and extends parallel
to stop member 37 through axis 25. ~rhe upper portion of
stop member 40 above a~is 25, as shown in Fig. 5, is also
provided with a forwardly fac~ng resilient seal strip 41,
while the lower portion of stop member 40 below axis 25, as
shown in Fig. 5, is provided with an oppositely rearwardly
facing resilient seal strip 42. Stops 37 and 40 and their
respective seal strips extend -the full distance between dia-
metrically opposed portions of wall 10.
Referring again to Fig. 5, when diverter element
20 is rotated to ils normal position, the por-tions of ribs
35 and 36 above axis 25 move rearwardly agains-t the for-
wardly faci.ng seals 38 and 41, while the portions of ribs 35
and 36 below axis 25 move forwardly against -the rearwardly
facing seals 39 and 42. Stop members 37 and 40 not only
positi.on diverter element 20 in pro~er normal positi.on, but
lheir respective seals isolate the housing i.nto two flow
chambers 15a and 15b and substantially prevent fluid leakage
or bypass around the exterior of the wall 21 of elemen-t 20.
A fur-ther block-li.ke stop member 43 may be mounted
on plate 11, spaced from s-top 37, for engagement by rib 35
to properly position diverter element 20 for reversing flow.
See Fig.s 3 and 4.
As can be seen from Fig. 3, when diverter element
20 is in .its normal position~ fluid flows in -through suppl.y
port 16, through chamber 15a and passage 23 and out port 18
in a generally straight line. Return fluid flows in through
port 19, through chamber 15b and passage 24 and ou-t return
port 17, parallel to but reversed from the supply flow.
sy permitting some of the fluid to flow through
passages 23 and 24, adjacent ports 16, 17 and 18, 19 can be
positioned closer together than was previously possible,
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thus providing for a smaller valve wi-th eaual capacity.
Referring to Fig. 4, when diverter element 20 is
in its .reverse :Elow position, fluid Elows in through
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supply port 16, -through chamber 15 and around diverter element
20, and discharges through port lg. ~eturn fluid flows in
-through port 18,-through bo-th passages 23 and 24 of diverter
element 20, and discharges through return port 17.
As discussed above, the previously ]snown valve con-
struction was subject to problems of undesirable bypassing
of fluid between the end edges of diverter element 20 and
baffle 22 and the inner surface of valve wall 10, as well as
binding at -the interface between the said end edges and valve
wall during rotative repositioning of element 20.
To solve this particular problem, seats 44 and 45
are moun-ted to the inner surface of cylindrical wall 10 bet~
ween respective ports 16,17 and 18,19 and are in-tersected by
the central longitudinal. plane 46 containing baffle 22 when
divexter element 20 is in its normal posi-tion. Seats 44,45
extend in one direction circumferen-tially toward and surround
the respective diagonally opposed ports 17 and 18. The sea-ts
extend in -the other direction circumferentially beyond plane
46 and terminate as at 47 and 48, on the side of the plane
~emote from respective ports 17 and 18~ See Fig. 6 as to seat
44.
Seats 44 and 45 are provided wi-th respective concave
faces 49 and 50 which, in section, are inclined planularly a-t
an acu-te angle (such as 5 for example) to axis 25 and -the
inner cylindrical surface of wall 10.
The circumferential end edges 51 of -tubular diver-ter
elemen-t 20, as well as the end edges 52 of baffle 22 are pro-
vided ~1ith a planular slan-t which corresponds in degree and
position to the angle of incline of faces 49 and 50. Thus,
the element 20 and faces 49,50 will engage, in section, at a
planular interface.
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When diverter element 20 is in its normal posi-tion,
as shown in Fig. 3, leakage or bypass be-tween -the supply and
return fluid flows is reduced by engagement of baffle end
edges 52 with seat surfaces 49 and 50 adjacen-t the interscc-tion
with plane 46.
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ci.rcumferentially end edyes 51 of diverter element 20 do
seat against poxtions of seat surfaces 49 and 50 but do not
contribute essentially to the bypass reducing function.
Note tha-t end edges are freely exposed to ports 16 and 18.
When diverter element 20 is in its secondary rota-
ted position, as i.n Fig. 4, leakage or bypass between the
supply and return fluid flows is reduced by engagement of
diverter element end edges 51 with the por-tions of seat
surfaces 49 and 50 in the areas surrounding respective ports
18 and 17. In this instance, baffle end edges 52 are freely
exposed to these ports.
Means are provi.ded to selectively shift diver-ter
element 20 on its axis 25 to either firmly tighten end edges
51 and 52 onto seats 44 and 45 to thereby substantially
eliminate bypass of fluid, as previously described, or -to
lift edges 51 and 52 from their seats so that di.verter
element 20 can be rota-ted between normal and reverse flow
position without binding.
For this purpose, and in the presen-t embodiment,
pinion 30 forms part of a hollow housing 53, one end of
which slidingly receives a hex-shaped end 54 of stub shaft
27. A threaded shaf-t 55 ,extends axi.ally through housing 53
with its inner end threaded into end 54. A retainer 56 is
fixedly secured to -the outer end of housing 53, as by bolts
57, and serves to captur:e an adjusting nut 58 through which
shaft 55 is threaded. A lock nut 59 iS also threaded on
sha-ft 55 and serves -to -ti.ghten or loosen nut 58.
When it is desired to firmly tighten diverter
element 20 and baffle edges 52 onto seats 44 and 45! lock
nut 59 is manually or otherwise loosened and adjusting nut
58 is turned, causing threaded shaft 55 to move inwardly on
its axis, this being axis 25, shi.fting diverter element 20
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so that baffle edges 52 are tlghteningly seated, as in Fig.
When i-t i.s desired -to shift diverter element 20
from normal to reverse flow position, which is about a
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35- turn, lock nut 5g is loosened so that adjusting nut
58 can he turned on shaft 55 to lift element 20 away from
seats 44 and 45, as shown in exaggerated form in FIG. 9.
Element 20 will then be free to turn to its flow
reversing position without binding, as shown in exaggerated
form in FIG. 10. In that reverse Elow position, diverter
element 20 can be lowered so that its edges 51 engage
seats 44 and 45 if desired. However, in the contemplated
use for shuttle brush cleaning of condenser tubing, some
bypassing of fluid flow between supply and return during
reverse flow can be tolerated. This is due to the fact
that brush cleaning may be used for only about two minutes
out of six hours of total operation, and even with fluid
bypassing occurring, there will be sufficient pressure to
drive the brushes.
Slight loosening of element 20 from its seats 44
and ~5 c/n also be accomplished while leaving element 20
in its normal position, if a slight tolerance adjustment
is desired.
During axial shifting of the normally positioned
element 20, ribs 35 and 36 will merely slide along resilient
seals 39 and 42 to maintain the longitudinal seal, even
while fluid is flowing through the valveO
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