Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TAPERED AIR PURGING CIRCULATOR
Backgiround Of The Inyention
(0002) Air can enter a hydronic (hot water) heating system in nun-
ber of ways. Most typically, air enters the system as a result of some repair
or replacement of a component of the system. If, for example, a boiler is re-
placed, the entire system typically must be drained and refilled with water.
(0003) The removal of air in a hot water heating system is conven-
tionally done in two steps. The first step is to remove the large pockets of
air
by purging the system with a fiose. The second step is to remove the left-
over smaller pockets of air by an air scoop or microbubbler.
(0004) In the first step, a shut off valve is opened on the fill line
leading to the boiler and the system is filled until 12 psi is reached. Then a
hose is attached to a drain valve in the system piping and the shutoff valves
for each split,.off of each zone, are closed. The drain valve is opened and
the pressure is increased in the system by adjusting the fill valve to let
water
into the system. If that doesn't work, the fill valve must be bypassed with a
double-end hose. Most of the time the drain valves are not properly placed
to do this. The water is then circulated through the system until new v~ater
replaces the water already in the system. The hose is then moved to the
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next drain valve and the step of circulating v~ater to replace existing water
with new water is repeated for each split of each heating loop. This task
takes 1.25-2.5 hours and must be added to every repair done in the system.
If the fill valve breaks due to excessive pressures during filling of the
system,
the entire process may have to be repeated.
(ooos~ In the second step, after the biggest pockets of air are gone,
small.bubbles remain, causing gurgling noises in the pipes of the hot water
system. These small bubbles are removed by air scoops or nicrobubblers
installed in the system. If properly installed, these devices will eventually
purge most of the remaining air within 24 hours and the system should circu-
late smoothly and quietly.
(ooos] If the smaller bubbles are not removed, they can accumulate
into bigger pockets of air. These large pockets of air, if they are drawn
through the system to the impeller chamber of the circulator, can cause stall-
ing of circulation of the water through the system, so fiat no heat is
delivered
to the radiators located downstream of the circulator. In other cases, the air
pocket can become trapped in one of the zones of the heating system, pe-
venting circulation through that zone. If these protiems occur in the winter,
there.is the possibility of the pipes freezing and bursting if the problems
are
not promptly solved.
(0007 A number of systems have been proposed to provide gas
separation equipment in a hyrdronic heating system, but to date, none of the
proposed systems have been suitable for use in retrofit applications, i.e., n-
stallation into preexisting hydronic heating systems. Thus, the system in U.S.
Patent No. 3,290,864 is complicated, and would require ecpensive repiping
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to install the pump where system piping is run close to a wall. The system in
U.S. Patent 4,775,292 is not suitable for orientation in more than one direc-
tion, thus limiting its application to limited situations where a preexisting
circu-
lator pump is oriented in the same way as the intended use of the system
shown in this patent. In addition, this system would not be useful to install
the pump where system piping runs close to a wall.
(0008 More recently, I have invented a new design for a retrofit cir-
culator, as disclosed in U.S. Patent 6,129,523, issued October 10, 2000,
which provides a circulator for hydronic systems which can automatically re-
move air in the system, without need for laborious hose purging of the sys-
tem, and which is suitable for retrofit applications regardless of the
position-
ing or orientation of the existing circulator or piping in the system.
(0009 The present invention improves upon and extends this origi-
nal design.
Summary of the invention
(ooo~o~ In accordance with one embodiment of the invention, an air
purging circulator comprises a pump housing which is tapered from an inlet
end to a pump end. In the preferred embodiment, the housing is a horizontal
frustoconical shape, similar to a coffee cup positioned on a horizontal axis.
The circulator has an inlet aperture and an outlet aperture at one end, gener-
ally axially aligned with each other. The inlet leads to a reservoir and from
there to an impeller chamber. The impeller chamber is at one end of the
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housing and contains an impeller driven by an electric motor
at an end of the circular opposite from the end containing
the inlet and outlet. The impeller chamber preferably
connects to the outlet aperture in the pump housing by a
curved passageway that extends from the impeller chamber to
the outlet aperture.
[0011] The air purging circulator is particularly well
adapted to use in retrofit of existing systems, even where
piping is close by a wall. Preferably, the distance between
the inlet and outlet apertures of the pump housing is
selected to match the distance between flanges in
conventional circulators, to allow easy retrofit.
[0012] The air purging reservoir is sized to provide
reduction of the velocity of the circulating water in the
hydronic system as it passes through the air purging
reservoir on the suction side of the reservoir. This
location has the lowest pressure within the system, and
thus, the least amount of dissolved air in the circulating
water. The air contained in the circulating water separates
from the circulating water and, due to the frustoconical
shape of the reservoir, collects in an upper portion of the
air purging reservoir. The air purging reservoir has an air
vent provided in the upper portion thereof to release the
air collected in the reservoir. Preferably, the air purging
reservoir is provided with four apertures positioned at 90°
intervals around a peripheral wall thereof. In this way,
the air purging circulator may be oriented in any direction
and the air vent will be positioned on the upper portion of
the air purging reservoir.
In particular, according to one aspect of the
present invention there is provided an air purging
circulator for a hydronic heating system, comprising: a
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motor; a pump housing having an inlet aperture and an outlet
aperture, said inlet aperture connecting to an air purging
reservoir, said air purging reservoir having a generally
frusto-conical shape, said air purging reservoir being on a
suction side of an impeller chamber, an outlet from said air
purging reservoir connecting to said impeller chamber, said
impeller chamber connecting to said outlet aperture in said
pump housing; impeller means for pumping water in said
hydronic heating system operably connected to said motor and
located within said impeller chamber; said air purging
reservoir being sized to permit reduction of velocity of
circulating water in the hydronic system through said air
purging reservoir, air contained in the circulating water
separating from the circulating water while passing through
said air purging reservoir and collecting in an upper
portion of said air purging reservoir, said air purging
reservoir having an air vent provided in said upper portion
thereof to release air collected in said reservoir.
According to another aspect, there is provided an
air purging circulator for a hydronic heating system,
comprising: a motor; a pump housing having an inlet aperture
and an outlet aperture, said inlet aperture connecting to an
air purging reservoir, said air purging reservoir having a
tapered shape along its axial length, said air purging
reservoir being on a suction side of an impeller chamber, an
outlet from said air purging reservoir connecting to said
impeller chamber, said impeller chamber connecting to said
outlet aperture in said pump housing; said inlet aperture
and said outlet aperture of said pump housing being axially
aligned and being located at one end of said pump housing
opposite from said motor; impeller means for pumping water
in said hydronic heating system operably connected to said
motor and located within said impeller chamber; said air
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purging reservoir being sized to permit reduction of
velocity of circulating water in the hydronic system through
said air purging reservoir, air contained in the circulating
water separating from the circulating water while passing
through said air purging reservoir and collecting in an
upper portion of said air purging reservoir, said air
purging reservoir having an air vent provided in said upper
portion thereof to release air collected in said reservoir.
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[00~3~ In a preferred embodiment, the reservoir contains a sepaetion
media, such as a plate, marbles, wire mesh, or crumpled wire, to further slow
the water flow and enhance separation of the air from the water.
(00~4~ Other objects, aspects and features of the present inveition in
addition to those mentioned above will be pointed out in or will be undestood
from the following detailed description provided in conjunction with the ac-
companying drawings.
Brief Description of Drawings
(oo~s~ FIG.1 is a top, front and left side perspective view of a first em-
bodiment of an air purging circulator in accordance with the invention.
(oo~s~ FIG. 2 is a top, front and right side perspective view of the em-
bodiment of an air purging circulator of FIG. 1.
(oozy FIG. 3 is a perspective view of the embodiment of an air pug-
ing circulator of FIG. 1.
(oo~s~ FIG. 4 is a cross-sectional view of the embodiment of an air
purging circulator of FIG. 1.
(oo~s~ FIG. 5 is a cross-sectional view of the embodiment of an air
purging circulator of FIG. 1.
(0020] FIG 6A is a top and side perspective view of a flange for mount-
ing to a flanged pipe in an air purging circuhtor.
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(0021 FIG. 6B is a top and side perspective view of the first step of
mounting the flange to a flanged pipe in an air purging circulator.
(0022 FIG. 6C is a top and side perspective view of the second step of
mounting the flange to a flanged pipe in an air purging circulator.
(0023) FIG. 6D is a top and side perspective view of the third step of
mounting the flange to a flanged pipe in an air purging circulator.
(oo2a~ FIG. 6E is a top and side perspective view showing the com-
pleted mounting the flange to a flanged pipe in an air purging circulator and
assembly with another flanged pipe.
Detailed Description of the Drawings
(0025 The present invention has particular application in hydronic
heating systems, i.e., circulating hot water heating systems found in many
homes. Referring now to FIGS. 1-6E, an air purging circulator 30 for a hy-
dronic heating system is shown. In the Figures, the same numbers refer to
like elements in the different embodiments.
(oo2s~ Circulator 30 comprises an electric motor 32 (not shown), a
pump housing 34, and an impeller 36 (not shown). Pump housing 34 has an
inlet aperture 38 leading to an air purging reservoir 42. An outlet from the
air
purging reservoir 42 has an outlet aperture 44 connected to an impeller
chamber 46, such that the reservoir 42 is on the upstream, or suction side, of
the impeller chamber 46. Impeller chamber 46 is connected bar a passage-
way 48 to an outlet aperture 50 in pump housing 34. The impeller chamber
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46 preferably connects to the outlet aperture 50 in the pump housing 34 by a
curved tube 52 that extends from the impeller chamber 46, to the outlet aper-
ture 50.
~002~~ Impeller 36 for pumping water in the hydronic heating system is
operably connected to motor 56. Impeller 35 is located within impeller cham-
ber 46. Thus the air purging reservoir 42 is located on the suction side of
the
impeller 36 in circulator 30.
~0028~ Inlet aperture 38 and outlet aperture 50 are axiaNy aligned, so
that the circulator 30 may be installed in retrofit applications in place of
an
existing conventional circulator without requiring repiping, drainage of the
system, or other time-consuming and expensive alterations of the existing
hydronic heating system. Moreover, the distance between aperture 38 and
outlet aperture 50 is selected to be consistent with industry standards for ex-
isting circulators, to simplify installation of the circulator 30 into an
existing
hydronic heating system. Flanges are preferably associated with the inlet
aperture 38 and outlet aperture 50 and are preferably secured in a manner
allowing rotation of the flanges relative to the housing this manner, the air
purging circulator 30 can easily be retrofitted into existing systems that
have
mating flanges on installed pipes, because the flanges on the circulator 30
may easily be oriented to match up with the existing flanges in the
preexisting
heating system. Rotation of the flanges of the inlet and outlet apertures 38,
50 may be provided by a threaded connection between the flange and a nip-
ple extending from the circulator 30, or by a retaining collar for the flange
having sealing means between the flange and the collar.
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(oo2s~ In preferred embodiments, shown in FIGS. 1 and 2, the inlet
aperture 38 and outlet aperture 50 are positioned on one end of air purging
reservoir opposite from the motor 12. This configuration provides the added
advantage of fitting the circulator 30 into tight spaces,as where existing pip-
ing is fitted close to a wall. The provision of the inlet aperture 38 and
outlet
aperture 50 at end 54 of air purging reservoir 30 allows the circulator 30 to
fit
into the existing space, very nearly flush against a wall, where piping is
fitted
close.to the wall. As noted above, in the embodiment of FIG. 1, a curved
tube 52 preferably connects the impeller chamber 46 to the outlet aperture 50
of pump housing 34. The curved tube 52 is a smooth gradually curved tube
to provide a smooth transition from the impeller chamber 46 to the outlet 50,
and is believed to have a better flow rate and to reduce turbulence and mix-
ing of air into the water than a system where a winding path is provided from
the impeller chamber to the outlet.
(ooso~ Housing 34 and reservoir 42 contained therein have a tapered
diameter along their axial length. The Figures show a preferred embodiment
where housing 34 and reservoir 42 are frustoconical in shape along their
horizontal axis. The frustoconical shape, similar to a coffee cup laid on its
side, enhances the separation of air from the circulating water, and encou-
ages the separated air to rise up and exit through the uppermost of the vent
apertures 60.
(003~~ The air purging reservoir 42 is provided with four threaded vent
apertures 60 around a peripheral wall thereof at positions 90° apart,
for con-
necting air vent 64 to the air purging reservoir 42 using a nipple 66. The ap-
ertures 60 are aligned with the axis of the inlet and outets 38 and 50 and at
positions 90° away therefrom. The provision of vent apertures 60 at
these
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positions allows the air purging circulator 30 to be oriented in any
direction,
and the air vent 64 can be installed in the upper portion 62 of the air
purging
reservoir 42. The apertures 60 that are not used for the air vent 64 will be
plugged with a suitable threaded plug 68.
[0032 The air purging reservoir 42 is sized to permit reduction of ve-
locity of water in the hydronic system, and is located to remove air at the
point of lowest pressure in the system. This causes air bubbles cortained in
the water to separate from the water by and to be collected in an upper por-
tion 62 of the air purging reservoir 42. The air purging reservoir 42 has an
air
vent 64 provided in the uppermost of the vent apertures 60 to release air
collected in the air purging reservoir 42.
[0033 The air purging circulator may be an empty space; houvever, in
one embodiment, the air purging circulator 30 contains media that assists in
inducing the separation of air from the water. Baffle plates may also be used
in lieu of separation media. Separation media may comprise a randomly
stacked series of spherical materials such as marbles or it may comprise
packings of the type used in packed towers as are ki iiowi ~ I. i the a~r i of
chef
cal process equipment; or it may comprise a mesh or other material, such as
a crumpled wire media. The separation media acts to divert the viater flow
into numerous paths, further reducing the water velocity, to allow further
resi-
dence time for separation of air bubbles from the water.
[0034 A summary of the operation of the circulator of the inveition is
as follows. An air/water mixture in a hydronic heating system enters the c~-
culator through aperture 38 in housing 34, then enters the air purging reser-
voir 42. Air purging reservoir 42 is sized sufficiently large so as to allow
the
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mixture to reduce its speed. Air released by the low pressure, or that is mov-
ing with the water, separates by gravity from the water and collects in the ~p-
per end 62 of the reservoir 42. The aF is then vented out through automatic
vent 64. Vent 64 does not allow water to pass therethrough. Vent 64 is ~-
tached to reservoir 42 by a nipple 66 screwed into threaded vent aperture 60.
In a typical use, one air vent 64 will be installed in one of he apertures 60
after it is determined which aperture 60 will be topmost.
(oo3s~ After separation of the air/water mixture in reservoir 42, the v~a-
ter flows into impeller chamber 46 by suction from the impeller. The amount
of dissolved air in the water in impeller chamber 46 is significantly lower
than
the amount of air in the water entering reservoir 42. The water in,'impeller
chamber 46 does not contain enough air to stall the system. (In prior art sys-
tems the entire heating system would stall if enough air entered impeller
chamber 46, so that the impeller was spinning in the trapped air instead of
pumping water through the system.) After a few cycles of the water through
the air purging circulator 30 the smaller pockets of air disappear,
eliminating
banging and other noises associated with air in the hydronic system.
(oo3s~ Referring now to FIGS. 6A 6E, a preferred embodiment for ret-
rofit of the circulator of the invention into an existing home hydronic system
is
shown. A flange 90 is provided with a central opening 92, which has cutout
sides, and conventional bolt holes 94. Opening 92 is sized to fit over the lip
95 of the flaring tube end 96 in the circulator. The cutout sides allow the
flange to be oriented and manipulated to a position inward of the lip 95, so
that the flange 90 may be retained on the tube end 96, all as shown in the
series of steps at FIGS. 6A~E. Once the flange 90 is positioned in location,
it may be bolted to the corresponding flange of a pipe 100.
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~003~~ Accordingly, the present invention provides a new and useful
improvement in the filed of hydronic heating systems, by providing for elinr
nation of dissolved air in the circulating water in the heating sy~em.
m
