Note: Descriptions are shown in the official language in which they were submitted.
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FILTERING APPARATUS, FILTER REGULATOR FOR USE WITH SPRAY
GUN AND SPRAYING SYSTEM USING THE SAME
TECHNICAL FIELD
[0002] The disclosed embodiments relate to a filtering apparatus, a filter
regulator for
use with one or more spray guns, and a spraying system using the same.
BACKGROUND
[0003] Clean, compressed air has been known to be critical for operation of
equipment
that runs on compressed air, such as various air operated instruments, paint
spray equipment,
and other pneumatic devices that require oil and liquid free compressed
natural gas or air.
[0004] There is a need for devices that can provide such clean compressed air
or
compressed gas at the line pressure and/or a desired regulated pressure.
SUMMARY
[0005] In an aspect, a filtering apparatus includes a housing having an inlet
and at least
an outlet, and a filter arrangement disposed in the housing, downstream of the
inlet and
upstream of the outlet for filtering a pressurized gas entering the housing
through the inlet to
provide a filtered pressurized gas at the outlet. The filter arrangement has
first and second
tubular filter elements. The first filter element is received within the
second filter element.
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[0006] In another aspect, the filtering apparatus is configured as a filter
regulator when
equipped with a pressure regulator.
[0007] In a further aspect, a spraying system using the filtering apparatus or
the filter
regulator is provided.
[0007A] A further aspect of the present invention seeks to provide a filtering
apparatus,
comprising: a housing having an inlet and at least an outlet a filter
arrangement disposed in the
housing, downstream of the inlet and upstream of the outlet for filtering a
pressurized gas
entering the housing through the inlet to provide a filtered pressurized gas
at the outlet,
wherein the filter arrangement comprises first and second tubular filter
elements, and the first
filter element is located within the second filter element; and a pressure
regulator disposed in
an upper portion of the housing, downstream of the filter arrangement and
upstream of the at
least one outlet for regulating a pressure of the filtered pressurized gas in
accordance with a
setting of the pressure regulator to provide a regulated, filtered pressurized
gas at the at least
one outlet, wherein the upper portion of the housing comprises a unregulated
chamber and a
regulated chamber separated by a valve of the pressure regulator; and the at
least one outlet
comprises one or more regulated outlets formed in a wall of the regulated
chamber; the
filtering apparatus further comprising a unregulated outlet formed in a wall
of the unregulated
chamber for providing the unregulated, filtered pressurized gas at the
unregulated outlet.
10007B] Further still, one broad aspect of the invention seeks to provide a
spraying
system, comprising: a filtering apparatus, comprising: a housing comprising an
inlet and
multiple pressure-regulated outlets a filter arrangement disposed in the
housing,
downstream of the inlet and upstream of the outlet for filtering a pressurized
gas entering the
housing through the inlet to provide a filtered pressurized gas at the
outlets, wherein the filter
arrangement comprises first and second tubular filter elements, and the first
filter element is
located within the second filter element; a source of the pressurized gas
connected to the inlet
of the filtering apparatus; multiple spraying material reservoirs; and
multiple spray guns each
connected to a separate one among the spraying material reservoirs and a
separate one among
the pressure-regulated outlets of the filtering apparatus.
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[0008] Additional aspects and advantages of the disclosed embodiments are set
forth in
part in the description which follows, and in part are obvious from the
description, or may be
learned by practice of the disclosed embodiments. The aspects and advantages
of the disclosed
embodiments may also be realized and attained by the means of the
instrumentalities and
combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The disclosed embodiments are illustrated by way of example, and not by
limitation, in the figures of the accompanying drawings, wherein elements
having the same
reference numeral designations represent like elements throughout.
[0010] Fig. 1A is a front view of a filter regulator in accordance with an
embodiment
of the present invention.
[0011] Fig. 1B is a front-left-top perspective view of the filter regulator
shown in Fig.
1A.
[0012] Fig. 2 is a cross sectional view taken along line II-II in Fig. 1B.
[0013] Fig. 3 is a cross sectional view taken along line III-III in Fig. 1B.
[0014] Fig. 4 is a cross sectional view taken along line IV-IV in Fig. 3.
[0015] Fig. 5A is a view similar to Fig. 1B.
[0016] Fig. 5B is an enlarged, cross sectional view of circled area B in Fig.
5A.
[0017] Fig. 6 is an exploded view of the filter regulator shown in Fig. IA.
[0018] Fig. 7 is a perspective view showing the filter regulator of Fig. 1A
and two spray
guns.
2A
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[0019] Fig. 8A is a front view of a filter regulator in accordance with a
further
embodiment of the present invention.
[0020] Fig. 8B is a front-left-top perspective view of the filter regulator
shown in
Fig. 8A.
[0021] Fig. 9A is a cross sectional view taken along line IX-IX in Fig. 8B
showing
one half of the filter regulator; Fig. 9B is a perspective view of the other
half of the filter
regulator; Fig. 9C is a cutaway perspective view showing an internal structure
of the
filter regulator from the rear of the filter regulator; and Fig. 9D is a
cutaway perspective
view showing the internal structure of the filter regulator from the front of
the filter
regulator.
[0022] Fig. 10 is a cross sectional view taken along line X-X in Fig. 8B.
[0023] Fig. 11 is a cross sectional view taken along line XI- XI in Fig. 10.
[0024] Fig. 12 is an exploded view of the filter regulator shown in Fig. 8A.
DETAILED DESCRIPTION OF EMBODIMENTS
[0025] In the following detailed description, for purposes of explanation,
numerous
specific details are. set forth in order to provide a thorough understanding
of the
embodiments. It will be apparent, however, that the embodiments may be
practiced
without these specific details. In other instances, well-known structures and
devices are
schematically shown in order to simplify the drawing.
[0026] Figs. 1A and lB are front and perspective views of a filter regulator
100 in
accordance with an embodiment of the present invention. Cross-sectional views
of
filter regulator 100 are provided in Figs. 2-4. Fig. 6 is an exploded view of
filter
regulator 100. Figs. 8-12 are various views of a filter regulator 800 which is
a
simplified version of filter regulator 100 shown in Figs. 1-7. In particular,
filter
regulator 800 neither includes a line pressure gauge (such as 26), nor a
filter-change
indicator (such as 29). Additionally, valves 22, 23 of filter regulator 100
are replaced
with manual drain cocks 30, 31 in filter regulator 800. Filter regulator 800
is otherwise
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substantially identical to filter regulator 100 and filter regulators 100 and
800 will be
described in further detail herein together.
[0027] As can be seen in Fig. IA, filter regulator 100 includes a housing 101
which
in turn includes an upper portion or hollow body 1, and a lower portion or
bowl 2.
Body 1 and bowl 2 in an embodiment are separately manufactured and fastened
together, e.g., by bolts 651 shown in Fig. 6. Body 1 and bowl 2 can also be
attached by
threaded or bayonet connections. A sealing element, such as 0 ring 676 in Fig.
6, is used
in an embodiment to ensure that the connection between body 1 and bowl 2 is
airtight.
The above-described detachable arrangement allows for removal of bowl 2 from
body 1
for maintenance or service. Each or both bowl 2 and hollow body 1 can be made
of
metal or any suitable material, such as plastic. Other arrangements and/or
materials are,
however, not excluded.
[0028] Housing 101 includes an inlet 252 (Figs. 2 and 9B) which, in an
embodiment,
is located at the upper portion or body 1 of housing 101. Inlet 252 is
configured for
connection to a source (not shown) of pressurized gas, such as compressed air.
The
connection between inlet 252 and the source of pressurized gas can be of any
type known
in the art and will not be described in further detail herein. In the specific
embodiment
shown in Figs. 2 and 9B, inlet 252 is a hole arranged on a rear side of filter
regulator
100 and oriented upwardly. This arrangement facilitates connection, e.g., via
a hose, of
the source of pressurized gas to inlet 252, without causing significant
obstruction of the
work area in the front of filter regulator 100. Other arrangements are,
however, not
excluded.
[0029] Housing 101 further includes at least an outlet at which the
pressurized gas
that enters filter regulator 100 via inlet 252 and filtered by a filter
arrangement as will
be described hereinafter is provided as a filtered pressurized gas. In the
specific
embodiment disclosed in Figs. 1-6, there are four outlets 102-104 (Figs. IA-
113) and
105 (Fig. 6) provided at the upper portion or body 1 of housing 101. Outlets
102-105
are located at opposite lateral sides of filter regulator 100 and oriented
obliquely
downwardly as best seen in Fig. 9C. This arrangement avoids kinking of the
hoses (not
shown) to be connected to outlets 102-105. Other arrangements are, however,
not
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excluded. In addition, the number of the outlets of filter regulator 100 is
not limited to
four and may vary depending on the applications.
[00301 Among outlets 102-105 of filter regulator 100, outlets 103-105 are
regulated
outlets at which the filtered pressurized gas is provided at a desired
pressure regulated by a
pressure regulator as will be described hereinafter. In contrast, outlet 102
is a unregulated
outlet at which the filtered pressurized gas is provided at or near the line
pressure of the
unfiltered pressurized gas that enters filter regulator 100 via inlet 252. In
other words, the
pressure of the filtered pressurized gas at unregulated outlet 102 is not
regulated by the
pressure regulator. The regulated filtered pressurized gas at outlets 103-105
can be used
for applications that require clean or filtered pressurized gas at a specific
pressure, for
example, paint spraying or paint pressurizing. For applications that do not
require the
filtered pressurized gas to be at a specific pressure, such as duster guns,
unregulated outlet
102 can be employed. Again, the numbers of regulated and unregulated outlets
of filter
regulator 100 are not limited to the specifically disclosed numbers, and may
vary
depending on applications. For example, all outlets can be regulated outlets
or unregulated
outlets. In the latter case, i.e., all outlets are unregulated outlets, the
pressure regulator can
be omitted and filter regulator 100 becomes a filtering apparatus that simply
provides
filtered pressurized gas without any pressure regulation. Other arrangements
are,
however, not excluded.
[0031] As can be seen in Fig. 6, each outlet 102-105 is equipped with a valve
653 for
selectively opening and closing the outlet. In an embodiment, valves 653 are
ball valves as
best seen in Fig. 9C, but valves of other types can be used. Each outlet 102-
105 includes
multiple holes 654, 655 for respectively fitting the main body and handle of
valve 653 as
shown in Fig. 6. Other arrangements are, however, not excluded. In addition,
one or
more valves 653 can be omitted or provided separately from filter regulator
100 in
which case the respective outlets 102-105 will be connected to the separately
provided
valve or valves by fittings or the like.
[00321 Return now to Fig. 2 where the internal structure of filter regulator
100 is
depicted. In particular, filter regulator 100 includes, besides housing 101, a
filter
arrangement 256 which is located downstream of inlet 252 and upstream of
outlets 102-
105 for filtering the pressurized gas that enters filter regulator 100 via
inlet 252 and
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providing the filtered pressurized gas, either pressure-regulated or
unregulated, at
outlets 102-105.
[00331 Filter arrangement 256 is located in the lower portion or bowl 2 of
housing
101 and includes at least two filter elements 4 and 5 one arranged within
another. In the
specific embodiment of Fig. 2, outer filter element 4 is located upstream of
inner filter
element 5, meaning that the pressurized gas, in operation, moves in the
outside-to-inside
direction through filter element 4 then through filter element 5, and escapes
to the upper
portion or body 1 of housing 101 through the internal space within filter
element 5 as
shown by arrows in Fig. 9B. The upstream filter, i.e., filter element 4, is
configured as a
coarse filter, whereas the downstream filter, i.e., filter element 5, is
configured as a fine
filter. Coarse filter 4 is positioned upstream of fine filter 5 to remove
contaminants of
large size that would otherwise easily clog the fine filter 5. The reversed
arrangement
wherein outer filter element 4 is located downstream of inner filter element
5, meaning
that the pressurized gas, in operation, moves in the reversed, inside-to-
outside direction
is not excluded but would require certain rearrangement of parts.
[00341 In a specific embodiment, the coarse filter or filter element 4 is a
particulate or
porous filter, whereas the fine filter or filter element 5 is a coalescing
filter or a coalescer.
[00351 Particulate filter 4 is configured for removing particles, such as
dirt, rust and
pipe scale, of a certain size from the pressurized gas and preventing such
particles from
clogging the downstream filter element, i.e., coalescing filter 5. Thus,
particulate filter 4
functions as a pre-filter that insures long service life and high efficiency
of coalescing filter
in particular and filter arrangement 256 as well as filter regulator 100 in
general.
Particulate filter 4 can be configured in any manner known in the art. For
example,
particulate filter 4 may include a mesh or porous material of a certain mesh
size. In an
embodiment, particulate filter 4 comprises a plurality of plastic balls or
spheres
compressed together until a predetermined porousness is obtained. In an
embodiment,
particulate filter 4 is configured to trap or intercept particles as small as
1 gm in diameter.
Other arrangements and/or mesh sizes are not excluded.
[00361 Coalescing filter 5 is configured for removing oil and/or water and/or
other
liquid substance and/or their vapor from the pre-filtered pressurized gas that
has passed
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particulate filter 4. Coalescing filter 5 is also responsible for trapping
very fine particles
that escape particulate filter 4. Coalescing filter 5 can be configured in any
manner known
in the art. For example, coalescing filter 5 may include a fibrous assembly
comprising a
plurality of fine fibers which, in an embodiment, can be micro-fibers having a
sub-micron
diameter or a diameter of a few to several tens of microns ( m) depending on
applications. Such fibers or micro-fibers can be glass fibers or glass micro-
fibers arranged
in a single layer or several layers. Other arrangements and/or material and/or
fiber sizes
are, however, not excluded.
[00371 Coalescing filter 5 generally removes solid contaminants in a direct
impact
and/or interception mode, and liquid or vapor contaminants in a diffusion
mode. In
particular, solid contaminants (i.e., fine particles that escape particulate
filter 4) of a
specified size and/or mass collide with the fibers or other filter media used
in coalescing
filter 5 and adhere thereto. Liquid or vapor contaminants, e.g., aerosols,
which also
strike the fibers or filter media when a stream of the pre-filtered
pressurized gas passes
through coalescing filter 5, do not permanently adhere to the fibers or filter
media. Rather,
the aerosols are united together as they move under gravity down along the
fibers to
form larger drops. The drops grow until their masses are sufficient to cause
the drops to
fall out of the fibers or filter medium or media of coalescing filter 5 to be
subsequently
drained away.
[0038] As can be seen in Fig. 2, coalescing filter 5 includes an inner support
layer or
core 257 and an outer filter medium 258. Alternative arrangements, wherein
filter
medium 258 is on the outer side and support layer 257 is on the inner side, or
wherein
multiple filter media 258 are provided on both inner and outer sides of
support layer
257, or wherein multiple support layers 257 are provided on both inner and
outer sides
of one or more filter media 258, are not excluded.
[0039] Support layer 257 is configured to provide mechanical strength to
coalescing
filter 5 as a whole. Support layer 257, in an embodiment, is configured as a
perforated
sleeve. A suitable material for support layer 257 includes metals, such as
stainless steel.
Other arrangements and/or materials are, however, not excluded.
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[0040] Outer filter medium or media 258 can include one or more fibrous layers
as
described above. The fibrous layers can be smooth or pleated. Filter medium or
media
258 may also include or coated with a drainage layer, which can be
hydrophobic, for
facilitating drainage of coalesced liquid, e.g., oil or water. Filter medium
258 in an
embodiment is configured to remove liquid droplets and particles as small as
0.1 micron
in diameter with an efficiency as high as 95% or greater. Again, other
arrangements
and/or materials and/or filter size and efficiency are not excluded.
[0041] As can be seen in Fig. 6, filter element 4 and filter element 5 are
separable
from one another and can be individually serviced and/or replaced. It is,
however, not
excluded that the filter elements can be made integral in a single filter
cartridge for
facilitating assembly of the filter regulator 100, and/or ensuring the desired
quality or
cleanness of the filtered pressurized gas when the entire filter arrangement
256 is
replaced. It should be noted that filter arrangement 256, in other
embodiments, may
include more than two filter elements. The filter elements are not necessarily
cylindrical in shape as specifically disclosed in Figs. 2-6. Rather, one or
some or all of
the filter elements can have a conical or truncated conical shape. The filter
elements are
not required to be circular in cross section and can have other cross
sectional shapes,
such as square, hexagon, etc.
[0042] Filter arrangement 256 is supported from below, in accordance with the
embodiment shown in Fig. 2, by a bottom plate 7 which has a single or several
grooves
best seen in Fig. 6 for receiving therein lower ends of filter elements 4, 5.
The groove
or grooves temporarily fix filter elements 4, 5 in place for assembly of
filter regulator
100. Bottom plate 7 further includes at least one through hole 359 for
draining away the
liquid coalesced by coalescing filter 5. There are four through holes 359
depicted in
Figs. 3-4, however, any other number of such through holes can be provided in
bottom
plate 7. The through holes 359 in the embodiment of Fig. 2 are located
corresponding
to the space between filter elements 4 and 5. Other arrangements are, however,
not
excluded. For example, through holes 359 can be provided below and/or radially
inside
coalescing filter 5. Bottom plate 7 can be made of any suitable material such
as plastic
and/or metal. In an embodiment, bottom plate 7 includes a plastic disc that
defines the
groove or grooves for positioning filter elements 4, 5, and a metal, e.g.,
brass, member
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at the center of such disc for reliable connection to a rod 8 as will be
described in detail
herein below. Other configurations and/or materials are not excluded.
[0043] A cup 6 is disposed below bottom plate 7 for collecting therein the
coalesced
liquid that has passed through holes 359. As best seen in Fig. 6, cup 6
includes an upper
enlarged portion 660 and a lower narrow portion 661. Upper enlarged portion
660 of
cup 6 is configured to sealingly receive therein bottom plate 7. An O-ring 662
can be used
for sealing between cup 6 and bottom plate 7. Lower narrow portion 661 of cup
6 in an
embodiment has a funnel shape. Other shapes are, however, not excluded.
[0044] Lower narrow portion 661 has an opening 363 (Fig. 3) at a bottom of cup
6 for
draining away the coalesced liquid collected in cup 6. Lower narrow portion
661 is
sealingly fit in a hole 364 at a bottom of bowl 2. In the embodiment of Fig.
3, no separate
O-ring is required for sealing between lower narrow portion 661 and hole 364.
For
example, the outer wall of lower narrow portion 661 and/or the inner wall of
hole 364 may
include resilient ribs for frictionally holding lower narrow portion 661 in
hole 364 and
sealing between the elements. Cup 6 can be made of any suitable material, such
as metal
or plastic. When cup 6 is made of plastic, the resilient ribs at the outer
wall of lower
narrow portion 661 can be molded together with the remainder of cup 6, and cup
6 so
manufactured can be press-fit into hole 364 at the bottom of bowl 2. Other
arrangements,
such as when an O-ring is used for sealing between cup 6 and bowl 2, are not
excluded.
[0045] Cup 6 and the inner wall of bowl 2 in an embodiment include matching
flanges
which engage, as best seen in Figs. 2-3, when cup 6 has been sufficiently
pressed into hole
364 at the bottom of bowl 2, thereby stopping cup 6 from being further pressed
into hole
364. As described above, hole 364 of bowl 2 and lower narrow portion 661 of
cup 6 are in
sealing contact or have a sealing element therebetween. However, the inner
side wall, e.g.,
372 (Fig. 3), of bowl 2 and the outer side wall, e.g., 673 (Fig. 6) of cup 6
are not entirely in
sealing contact. Cup 6 in some embodiments even includes one or more cutout
portions in
outer side wall 673. As a result, there is a fluid communication between a
space 374 (Fig.
3), which is located above cup 6 and between inner side wall 372 of bowl 2 and
filter
element 4, and a space 375 (Fig. 3), which is located below cup 6. Such fluid
communication allows water or liquid drops and, sometimes, solid particles to
flow along
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inner side wall 372 of bowl 2, pass cup 6 and collect in space 375 for being
drained away, as
will be described herein after.
[00461 Inside opening 363 at the bottom of cup 6, a valve 23 is provided for
selectively
opening and closing opening 363. Valve 23 can be an automatic valve or a drain
cock. In the
embodiment of Fig. 2, valve 23 is an automatic valve of a float type which
will be
automatically opened when the coalesced liquid in lower narrow portion 661 has
reached a
predetermined level. A manual valve or drain cock can be used instead, as
shown at 30 in Fig.
8B and 9. Valves of other types, such as electronic automatic valves, are not
excluded.
[0047) At the upper end of filter arrangement 256, a deflector 3 is positioned
as best
seen in Figs. 2-3. Deflector 3 has fins around its edge as best seen at 665 in
Fig. 6. Fins 665
are slanted relative to the axial direction of filter arrangement 256 and/or
axial direction of inlet
252 for imparting a swirling motion to the flow of pressurized gas entering
housing 101
through inlet 252 as will be detailed herein after. Deflector 3 can be
generally annular in shape
as disclosed in Fig. 6, or may include a cylindrical skirt. Generally,
deflector 3 is stationary
and does not rotate despite the flow of pressurized gas in filter regulator
100.
[00481 Deflector 3, in an embodiment, is self-positioned on top of one and or
both of
filter elements 4, 5 by a groove on its underside that matched with the top
end of the filter
elements 4 and/or 5. In a further embodiment, a cap 266 (Fig. 2) is used to
center deflector
3 on top of filter arrangement 256. In particular, cap 266 is fit in a central
hole of deflector
3 on the one hand, and fits over the top end of filter element 5 on the other
hand, as shown
in Fig. 2. Cap 266 and/or deflector 3 function as bottom plate 7 to
temporarily fix filter
arrangement 256 in place before assembly of filter regulator 100. Cap 266
and/or deflector 3
and bottom plate 7 also function to maintain a desired spacing between filter
elements 4, 5 of
filter arrangement 256.
100491 Besides hole 364, bowl 2 further includes another hole 369 (Fig. 3) at
its bottom
for draining water or other liquids collected therein due to the swirling
motion imparted by
deflector 3 to the stream of pressurized gas, as will be described in detail
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herein below. Like hole 364 and opening 363, hole 369 is also equipped with a
valve
22 (Fig. 3) or 30 (Fig. 10) for selectively draining the collected liquid or
water.
[0050] A fastening rod 8 is provided to fasten bottom plate 7 with the upper
portion
or hollow body 1 of housing 101, thereby clamping filter arrangement 256
together with
deflector 3 and cap 266, if provided, therebetween. Specifically, rod 8 in the
embodiment of Fig. 2 includes two threaded ends that can be threadedly,
removably
screwed into respective threaded holes 267, 268 in bottom plate 7 and hollow
body 1.
Other connection types, such as bayonet connections, can be used at either or
both ends
of rod 8. It is not excluded that rod 8 can be made integral with either of
bottom plate 7
and hollow body 1. In an embodiment wherein rod 8 is screwed or otherwise
detachably connected with hole 267 of bottom plate 7, such hole 267 is
provided in a
metal, e.g., brass, member at the center of bottom plate 7 for ensuring
desirable
mechanical strength of the connection. In this case, bottom plate 7 can be
formed by
molding a plastic disc portion around the brass member.
[0051] In an embodiment, 0-rings, such as 670, 671 in Fig. 6, are used to seal
between filter element 4 and deflector 3 at the upper end of filter element 4
and bottom
plate 7. Although Fig. 6 does not disclose any O-rings or other sealing
elements
between filter element 5 and deflector 3 and bottom plate 7, such O-rings or
sealing
elements can be provided in accordance with other embodiments.
[0052] In addition, although Fig. 6 discloses cap 665 and deflector 3 as being
separate from hollow body 1, the elements in some embodiments can be made
integral
with hollow body 1 for reducing the number of parts. In an alternative
embodiment,
only cap 665 is made integral with hollow body 1, whereas deflector 3 is made
as a
separate element. Other arrangements are, however, not excluded.
[0053] The operation of the filtering section of filter regulator 100 as
described
above will now be explained with reference to Figs. 9B-9D.
[0054] A flow of pressurized gas, such as compressed air, enters filter
regulator 100
or 800 through inlet 252 as indicated by arrow A in Fig. 9B. The pressurized
gas flow
is guided into a swirling pattern by deflector 3 as indicated by arrows B in
Fig. 9B.
Water, oil or other liquids as well as some solid contaminants, such as
debris, contained
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in the pressurized gas are separated from the pressurized gas flow as a result
of
centrifugal force caused by the swirling motion and are forced to inner side
wall 372 of
bowl 2 by such centrifugal force. The separated solid contaminants, water, oil
or other
liquids slide down inner side wall 372 of bowl 2, pass cup 6 and collect in
space 375
below cup 6. Thus, cup 6 functions as a baffle that creates a quiet zone,
i.e., space 375, at
the bottom of bowl 2, and prevents the swirling pressurized gas flow from
reaching the
solid contaminants, water, oil or other liquids that have been collected at
the bottom of
bowl 2. In this manner, the accumulated contamination (solid and/or liquid) is
ultimately
kept out of the swirling pressurized gas flow, and remains at the bottom of
bowl 2 without
being entrained or re-entrained back into the swirling pressurized gas flow,
until such
accumulated contamination can be removed from bowl 2 via drain cock 30 or
automatic
drain 22.
[0055] The swirling pressurized gas flow in space 374 continues to pass
through
filter element 4 which removes most solid particles. The swirling pressurized
gas flow
having passed filter element 4 then enters a space 377 between filter elements
4 and 5 as
a flow of pre-filtered pressurized gas.
[0056] Then, the pre-filtered pressurized gas flow continues to pass through
filter
element 5 (arrows C in Fig. 9B) which will trap the fine solid particles that
have passed
filter element 4 as well as liquid particles, e.g., droplets of water, oil or
other liquids,
and/or their vapor. The captured droplets combine or coalesce and are
subsequently
pulled by gravity down to the lower end of filter element 5 where the
coalesced water
oil or liquids flow through through holes 359 of bottom plate 7 into the
bottom section
of cup 6.
[0057] Bottom plate 7 functions as a baffle that creates a second quiet zone
378 at
the bottom of cup 6, and prevents the pre-filtered pressurized gas flow from
reaching the
contaminants and coalesced water, oil or other liquids that have been
collected at the
bottom of cup 6. The accumulated contamination remains at the bottom of cup 6
without being entrained or re-entrained back into the pressurized gas flow,
until it is
removed from cup 6 via drain cock 31 or automatic drain 23.
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[0058] It should be noted that quiet zone 375 is separated from quiet zone 378
by the
side wall, e.g.; 679 (Fig. 6), of the bottom section of cup 6. Thus, the
contaminants
either solid or liquid in the quiet zones, which are under different pressures
due to the
pressure drop across filter element 4, will not be mixed. As a result, there
is no
likelihood that the contamination in quiet zone 375 might be entrained or re-
entrained
back into the pre-filtered pressurized gas flow in space 374 via the less-
pressurized
quiet zone 378.
[0059] The clean, filtered pressurized gas that has passed filter element 5
enters an
inner space 380 (Figs. 3 and 9B) of filter element 5, and flows upwardly to
the interior
of hollow body 1 as indicated by arrow D in Fig. 9B. If filter regulator 100
or 800 is
configured solely for filtering purposes, i.e., without pressure regulation,
the filtered
pressurized gas will be directly delivered to the outlets 102-105, which in
this case are
unregulated outlets, and subsequently supplied to connected external devices
that run on
pressurized gas when the respective valves 653 are open. However, if pressure
regulation
is desirable, a pressure regulator, such as 281 (Fig. 2), will be required.
[0060] Pressure regulator 281 can be configured in any manner known in the
art.
[0061] In the specific embodiment of Figs. 2 and 9B-9D, pressure regulator 281
includes a valve 282 that separates the interior of hollow body 1 into two
chambers, i.e., an
upstream chamber 283 (al so shown in Fig. 9C) and a downstream chamber 284 (al
so
shown in Fig. 9D). Upstream chamber 283 is in fluid communication with inner
space
380 of filter element 5 and receives the filtered pressurized gas therefrom.
Upstream
chamber 283 is also in fluid communication with unregulated outlet 102 as best
seen in
Fig. 9C. Since the pressure in upstream chamber 283 is unregulated, upstream
chamber
283 is a unregulated chamber and the unregulated, filtered pressurized gas is
provided at
unregulated outlet 102. Downstream chamber 284, on the other hand, is a
regulated
chamber meaning that its pressure is regulated by pressure regulator 281.
Downstream
chamber 284 is in fluid communication with regulated outlets 103-105 as best
seen in Fig.
9D, and a regulated, filtered pressurized gas is provided at the regulated
outlets 103-105.
[0062] Valve 282 includes a valve stem 10 and a valve seat 11. In the
specifically
disclosed embodiment of Fig. 2, valve seat 11 is a flexible member or seal
that rests on
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an end of nut 12, which, in turn, is screw into an threaded recess in an inner
wall of
hollow body 1. A spring 9 is provided to bias valve stem 10 against valve seat
11,
thereby closing valve 282 at no-flow. The provision of nut 12 allows easy
assembly of
valve 282, wherein spring 9, valve stem 10 and valve seat 11 are placed in a
receiving
cavity within hollow body 1, and nut 12 is subsequently threaded in to its
receiving
recess to fix valve 282 in place.
[0063] Valve stem 10 further extends through aligned central openings of nut
12 and
disc 15 to engage an opening (right opening in Fig. 9B) of a through hole 689
(Fig. 6) at
a central portion 685 (Fig. 6) of a diaphragm 14. A tapered or rounded end 938
of valve
stem 10 rests against a surface around the right opening in Fig. 9B of through
hole 689,
and therefore, a movement of central portion 685 having through hole 689 to
the right
(in Fig. 9B) will move valve stem 10 to the right (in Fig. 9B) against action
of spring 9.
The right opening (in Fig. 9B) of through hole 689 is normally sealingly
closed by valve
stem 10 and O-ring or seal 24. However, valve stem 10 is not rigidly fixed to
through
hole 689 or any other part of central portion 685 or diaphragm 14. Thus, a
movement of
central portion 685 having through hole 689 to the left (in Fig. 9B) will not
move valve
stem 10 therewith. As a result, the right opening (in Fig. 9B) of through hole
689 can
be open by a clearance between seal 24 and tapered or rounded end 938 of valve
stem
10. In an embodiment, central portion 685 of diaphragm 14 is made of a rigid
material,
such as metal or rigid plastic, whereas its peripheral portion 686 (Fig. 6) is
made of a
deformable material, such as rubber, rubber-coated fabric, or fabric-
reinforced rubber.
The peripheral portion of 686 in a further embodiment is elastically
deformable. Other
arrangements and/or materials are, however, not excluded.
[0064] Peripheral portion of 686 of diaphragm 14 is tightly clamped between
the rim
of dick 15 and a spring housing 16 when spring housing 16 is fastened against
hollow
body 1 by way of, e.g., bolts 687 (Fig. 6). Other connection types, e.g.,
threaded
connection, between spring housing 16 and hollow body 1 can be used as well.
As a
result of such construction, central portion 685 of diaphragm 14 and, hence,
valve stem
is movable back and forth about a rest position due to the flexibility of
peripheral
portion of 686 of diaphragm 14. Disc 15 defines a diaphragm chamber 939 (Fig.
9B)
for diaphragm 14, thereby significantly reducing physical contact of diaphragm
14 with
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the main flow of filtered pressurized gas flowing through pressure regulator
281. Thus,
the service file span of diaphragm 14 can be prolonged. Diaphragm chamber 939
is in
fluid communication with downstream chamber 284 by orifice 688 (Fig. 6) formed
in
disc 15.
[0065] An adjustment spring 17 is provided in spring housing 16 and exerts a
spring
force, when compressed, on central portion 685 of diaphragm 14. The spring
force of
adjustment spring 17 is adjusted by knob 21 which engages an adjusting screw
19 via a
pin 20. An adjusting nut 18 is positioned at an end of adjustment spring 17
and
threadedly engaged with adjusting screw 19. When knob 21 is turned, adjusting
screw
19 is also turned which makes adjusting nut 18 to compress or release
adjustment spring
17. The invention is not limited to the above described configuration of
pressure
regulator 281 and other arrangements are not excluded.
[0066] The operation of the pressure regulating section of filter regulator
100 as
described above will now be explained.
[0067] The filtered pressurized gas is supplied from inner space 380 of filter
element
to upstream chamber 283. The pressure of the filtered pressurized gas in
upstream
chamber 283 has not yet been regulated and may fluctuate with the line
pressure
upstream of inlet 252. The unregulated pressure of the filtered pressurized
gas in
upstream chamber 283 together with spring 9 press valve stem 10 against valve
seat 11,
thereby closing valve 282. No filtered pressurized gas is provided to
downstream chamber
284 and its regulated outlets 103-105. The unregulated filtered pressurized
gas is,
however, available at unregulated outlet 102 of upstream chamber 283.
[0068] When knob 21 is turned, e.g., clockwise, to adjust a setting of
pressure
regulator 281 to a desired output regulated pressure, adjustment spring 17 is
moved to
the left in Fig. 2 (to the right in Fig. 9B). Diaphragm 14 is subsequently
moved together
with valve stem 10 to the left in Fig. 2 (to the right in Fig. 9B), thereby
unseating valve
stem 10 from valve seat 11 and opening valve 282. The filtered pressurized gas
flows
around valve stem 10, as indicated by arrow E in Fig. 9B, through a central
opening of
valve seat 11 to enter downstream chamber 284. The filtered pressurized gas is
now
available at regulated outlets 103-105.
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[00691 As downstream chamber 284 is in fluid communication with the diaphragm
chamber 939 through orifice 688 in disc 15, the pressure in the 'diaphragm
chamber 939
that acts against the action of adjustment spring 17, increases together with
the pressure in
downstream chamber 284, thereby applying an increasing force on the left side
of
diaphragm 14. It should be noted that the right opening (in Fig. 9B) of
through hole 689
is sealed by seal 24, allowing the pressure to build up in the diaphragm
chamber 939.
Diaphragm 14 and valve stem 10 move gradually to the right of Fig. 2 (to the
left in Fig.
9B), compressing adjustment spring 17. The movement of diaphragm 14 and valve
stem 10 stops when the pressure in downstream chamber 284, i.e., the pressure
in the
diaphragm chamber 939, balances the spring force of adjustment spring 17. If
one or
more of regulated outlets 103-105 is/are open, diaphragm 14 and valve stem 10
remain in
the balanced position and maintain the open state of valve 282, thereby
ensuring
continuous supply of the filtered pressurized gas at the desired or regulated
pressure at the
open regulated outlets 103-105. When regulated outlets 103-105 are all closed,
the
balance of forces occurs when valve 282 is closed. The pressure in downstream
chamber 284 is now at the desired level regulated by knob 21.
100701 The filtered pressurized gas trapped in downstream chamber 284 and
diaphragm chamber 939 can be released after regulated outlets 103-105 are
closed by
turning knob 21 in the opposite direction, i.e., counter clockwise, to reduce
the regulated
pressure. In particular, when the compressive force of adjustment spring 17 is
removed by
turning knob 21 counterclockwise, the pressure of the trapped filtered
pressurized gas in
downstream chamber 284 and diaphragm chamber 939 will move diaphragm 14 to the
left (in Fig. 9B). As valve stem 10 is stopped by nut 12 and seal 11, seal 24
carried by
diaphragm 14 will move relative to valve stem 10 to a position corresponding
to tapered
end 938 of valve stem 10, at which the right opening (in Fig. 9B) of through
hole 689
will open allowing the trapped filtered pressurized gas to escape diaphragm
chamber
939 and downstream chamber 284 through centre hole 689 of diaphragm 14 into
the
interior of spring housing 16 to be subsequently vented outside.
[00711 Other types of pressure regulators, such as electronic pressure
regulators, can
also be used in accordance with other embodiments of the present invention.
16
CA 02628982 2010-07-27
[0072] The pressure in downstream chamber 284 is indicated by a pressure gauge
27 mounted on the front side of hollow body 1. Pressure gauge 27 can be of any
type of
pressure gauges known in the art. Pressure gauge 27 is, in an embodiment,
threadedly
mounted in a hole 690 (Fig. 6) formed in hollow body 1 via a seal 691.
[0073] Likewise, the line pressure, or the pressure in space 374, is indicated
by a
pressure gauge 26 mounted on the front side of hollow body 1. Pressure gauge
26 can be
of any type of pressure gauges known in the art. Pressure gauge 26 is, in an
embodiment,
threadedly mounted in a hole 692 (Fig. 6) formed in the side wall of bowl 2.
[0074] Filter regulator 100 in some embodiment further includes a bracket 28
mounted at the bottom of bowl 2 for hanging one or more spray or duster guns
as shown
in Fig. 7. Guns 794, 793 in Fig. 7 can be spray guns of any type known in the
art.
Examples for guns 793, 794 are provided in U.S. Patent Application Publication
No. US
2003/0230636 which may be referred to for further details.
[0075] Filter regulator 100 in further embodiments includes a filter-change
indicator
29 mounted at a side of hollow body 1 for indicating when it is necessary to
replace either
one or some or all filter elements of filter arrangement 256. In the
specifically disclosed
embodiment of Figs. 5A and 5B, filter-change indicator 29 indicates when it is
required
to replace the entire filter arrangement of filter cartridge 256.
[0076] Filter-change indicator 29 in Fig. 5B is driven by the pressure
difference
between the line pressure and the pressure of the filtered pressurized gas. As
can be seen
in Fig. 5B, filter-change indicator 29 includes first chamber 595 and second
chamber 596
separated by a moveable partition, such as a piston 597. A diaphragm or other
elements
can be used instead of piston 597. First chamber 595 is in fluid communication
with space
380 or upstream chamber 283 of hollow body 1 and has the pressure of the
filtered
pressurized gas. Second chamber 596 is in fluid communication with inlet 252
or space
374 and has the line pressure. The pressure difference acting on piston 597 is
oriented to
the left in Fig. 5B and corresponds to the pressure drop across filter
arrangement 256.
Piston 597 is maintained in the retracted position shown in Fig. 5B by action
of
compression spring 598 which biases piston 597 to the right of Fig. 5B. When
filter
arrangement 256, especially filter element 4, becomes clogged, the pressure
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drop across filter arrangement 256 increases. The force acting on the right of
piston 597
also increases. When the clogging of filter arrangement 256 has reached an
unacceptable level, i.e., when the pressure drop across filter arrangement 256
has
become sufficiently, the force acting on the right of piston 597 outbalances
the spring
force of spring 598 and moves piston 597 to the left of Fig. 5B. As a result,
an outer
end 599 of piston 597 pops out to indicate that filter arrangement 256 need
service or
replacement. Filter-change indicator 29 can be arranged to individually
indicate the
clogging state of each filter element in filter arrangement 256 by connecting
first
chamber 595 and second chamber 596 to the respective spaces, such as 374, 380,
377
etc. Several filter-change indicators can be provided as well.
[0077] The embodiments disclosed above with reference to Figs. 1-7 provide
several
advantages. In particular, the arrangement of a front pressure adjusting knob
(21), a
vertical inlet (252) in the back of the filter regulator, four downwardly
inclined outlets
(102-105) providing both regulated and unregulated clean pressurized gas, and
enclosed
pressure gauges (26, 27) is unique. In the conventional filter regulators, the
inlet is at a
side, only one regulated outlet is provided, the pressure adjusting knob is at
the top of the
filter regulator, and the gauges are exposed.
[0078] Further, the arrangement of filter elements 4 and 5 with one inside
another is
also unique. The filter elements can be coaxial or concentric but off-center
arrangements are not excluded. In the conventional filter regulators, filter
elements 4
and 5 are placed in separate bowls and do not provide the 2-in-1 configuration
of the
filter arrangement 256 in accordance with the disclosed embodiments.
[0079] In addition, the mounting of pressure gauge 26 directly on the wall of
hollow
body 1 for indicating the line pressure is advantageous. In the conventional
filter
regulators, the line pressure is indicated by a separate gauge mounted outside
the filter
regulator, usually in the air line.
[0080] Furthermore, the provision of a water or liquid collection piece, such
as cup
6, advantageously allows two drains (22, 23) of two separate chambers (375,
378) to be
disposed in a single bowl (2). In the conventional filter regulators, only one
drain is
positioned inside a bowl.
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[0081] Additionally, the incorporation of valves 253 with hollow body 1 is
novel. In
the conventional filter regulators, the valves are separate from the filter
regulator and
are connected thereto by fittings.
[0082] Moreover, no known filter regulators provide a gun mounting bracket.
[0083] The disclosed embodiments are particularly suitable for spray painting,
but
other applications are not excluded.
[0084] While the present invention has been illustrated by the description of
the
embodiments thereof, and while the embodiments have been described in
considerable
detail, it is not the intention of the applicant to restrict or in any way
limit the scope of
the appended claims to such detail. Additional advantages and modifications
could be
made herein without departing from the scope of the described embodiments as
defined
by the appended claims. Furthermore, although elements of the described
embodiments
may be described or claimed in the singular, the plural is contemplated unless
limitation
to the singular is explicitly stated.
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