Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~ACKCIROUN~ ~F TIIE INv~r~TIoN
This invention relates to a reverse os~osis system
and particularly to an inte~ral dis~osable reverse osmosis
unit which may conveniently he inserted into and removed from
a system.
Brackish water has an unacceptable taste that can
be remedied by water treatment processes such as reverse
osmosis. Spirally wound, tubular, or hollo~ fiber reverse
osmosis membrane modules are used for reducin~ the mineral
quantity in potable water or in water used for preparin~ ice,
beveraqes, etc. These modules are housed in permanent
pressure vessels which may be made of PVC, stainless steel,
or iber reinforced plastic material. The reverse osmosis
process renuires a certain level of water pressure to push
the water throuqh the ~emhrane, leavinn the removed minerals
on the surface of the memhrane. The accumulated minerals are
washe~ off the membrane by a reject or waste stream of water
flowinq at a fairly hi~h velocity alon~ the surface of the
memhrane. This basic re~uirement of water pressure and water
flow can be met by line ~ressure existin~ in a water supply
system or can he provided hy a pump operatin~ to provide such
conditions. Hiqher water ~ressures result in ]ar~er flows
throuqh the membrane and also hetter rejection of unwanted
minerals.
The modules contained in presently used pressure
vessels slowly lose their effectiveness to remove minerals
due to various chemical and ~hysical aspects of mineral build-
up on the surface of the memhrane. When the flow throuqh the
membrane surfaces becomes too slow or too poor in quality for
intended end use, the water flow is sto~ed usually with an
appropriate valve ahead of the system, the pressllre vessel is
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o~ened, an~ the used reverse osmosis ~emhrane module is
re~oved from the vessel and discarded. A new memhrane module
is inserted into the vessel, retainin~ means are fastened,
the vessel is closed, and the valve is opened so that the
required operatina conditions can be reestahlished.
The process of chan~inq modules can be very messy
and time consumin~. In some areas under some operatin~
conditions, the chanqing process may have to be done often,
resultinq in hi~h maintenance costs. Additional difficulties
are encountered when the devices are located and mounted in
rather inaccessible places.
Accordin~ly it hecomes appropriate to develop a
reverse osmo.sis assembly in which an inteqral dis~osable
reverse osmosis unit can be inserted in a head me~ber and
then be removed and replaced as a unit thereby avoidinq a
pluarality of ~roblems now commonplace with existinq units.
SUM~1ARY OF THE INVENTION
A principal ohject of the invention herein is to
provi~e an integral reverse osmosis unit which can be easily
an~ quickly removed and replaced.
Another object is to provide an inte~ral reverse
osmosis unit which will avoid the piece by ~iece removal and
replacement of a used reverse osmosis module.
Another object is to provide a reverse osmosis unit
includin~ a pressure vessel hein~ constructed at its one end
in such a manner as to be easily insertable into and
removahle fro~ a`head memher which is mounted in a fluid
inlet line.
The above objects and advanta~es will beco~e more
ap~arent when considered in conjunction with the accom~anyin~
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drawinas and the ~ollowin~ description.
~RIEF DESCRIPTION OF THE ~RA~-~IN~S
Fiq. 1 is a view in elevation and partially in
section of a reverse osmosis ~ssemhly embodyin~ the invention
herein.
DESCRIPTION OF PREFERP~ED EMBODIME~T
The reverse osmosis system includes qenerally a
head memher 10, and a reverse osmosis unit 12 operatively
connected in the reverse osmosis system. In the embodiment
described herein a clampinn collar 14 is associated with the
hea~ member and is effective to sup~ort and releasably secure
the reverse osmosis unit in the head ~emher. The head member
10 is desiqned to be permanently mounted in a fluid inlet
line.
The head member 10 preferably is of plastic
construction. It has formed therein an inlet port 16 and a
pair of outlet ports 18 and 20. The inlet ~ort 16 is adapted
to be connected to a raw water supply system and is adapted
for fluid communication with a reverse osmosis unit. A valve
unit (not shown) is associated with the inlet port 16 to
control the flow of raw influent water to the inlet port.
The outlet ports also are adapted for fluid communication
with a reverse osmosis unit inserted into the head member.
One of the said outlet ports 1~ is the dischar~e port for
purified water cominn from the reverse osmosis unit and the
other of the outlet ports 20 is the dischar~e ~ort for waste
water cominn from the reverse osmosis unit.
The head member 10 is constructed internally with 3
concentric bores 22, 24 and 26 each adapted to sealin~ly
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enna~e tubular ~ortions of a closure memher of the reverse
osmosis~unit.
In the particular embodiment described herein the
clampinq collar 14 is operatively associated with the head
member 10 in the same manner as is described in U.S. Patent
No. 3,746,171 for a Filter Assembly issued July 17, 1973, and
assiqned to the same assiqnee as this a~plication. The
clampin~ collar 1~ in association with the head member 10
operates to retain a pressure vessel in the head member in
the same manner as is described in U.S. Patent No. 3,746,171.
It should he understoo(1 that other methods of
retaininq the pressure vessel in the head memher 10 could be
sed without departinq from the scope of the invention
herein.
The reverse osmosis unit comprises an elon~ated
pressure vessel 28~an end or closure member 30 disposed in
the open end of the ~ressure vessel, a reverse osmosis module
32 dis~osed in the pressure vessel 28 and attached to the
closure member 30 and an elon~ated tuhe 34 attached to the
closure ~emher 30 and extendinq throu~h the reverse osmosis
module. The pressllre vessel preferably is of metal
construction but may he of heavy plastic. The ~ressure
vessel is constructed with means for retainin~ it in the head
member. Such means may include a ~air of diametrically
disposed outstandinq ridqe surfaces 36 formed on the u~er
end thereof as described in U~S. Patent ~o. 3,746,171 issued
July 17, 1973, and assiqned to the same assiqnee as this
application.
The end or closure me~er 30 which is disposed in
and attached to tlle u~er end of the ~ressure vessel in sealed
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enqace~ent therewith is desiqned to cooperate with the head
memher 10. The closure member, which preferably is of a hard
plastic material, is formed with a plurality of passa~eways
which in the reverse osmosis syste~ form ~art of the inlet
and outlet passa~eway system for permittin~ fluid to enter
and exit from the reverse osmosis unit. The closure member
30 is of such construction as to provide the appropriate
passaqeway system and at the same time be compatible with the
head memher into which it is adapted to be inserte~. As here
shown the closure member is of a somewhat ~enerally tapered
or conical-like construction. This constrllction, however,
may take various for~s to acco~odate the construction of the
particular hea~ member with which it is to be associated.
The closure ~e~her is annular in constrllction to fit in the
open end of the pressure vessel 28. It includes a first
tuhular portion 38 a second tubular portion 40 and a third
tubular portion 42 all disposed coaxially with each other, a
ri~ ~ortion 44 also disposed coaxially with said first,
second and third tubular portions and a weh portion 46
interconnectin~ the third tuhular portion 42 and rim portion
44. An axial hore 48 extends throu~h the first tubular
portion 38 to define a fluid inlet passaqe 50. The second
tubular portion 40 is radially spaced from the first tubular
portion 38 to define therebetween a second fluid passa~e 52,
and a third tubular portion 42 is spaced from the second
tubular portion 40 to define a third fluid passa~e 54. Seal
means is associated with each of said tubular portions to
provide sealinq enqaqe~ent with the head ~emher 10 into which
the reverse os~osis unit 12 is inserted. As herein shown
O-rinq seals 56, 58 and 60 are disposed on the first, second
and third tubular ~ortions res~ectively to provide sealin~
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enqaqement with bores 22, 24 and 26 respectively of the head
member 10.
The rim portion 44 of closure member 30 is
sealinqly positioned in the upper end of pressure vessel 28.
The closure me~ber may be constructed with an annular base
~emher 62 in its lower end, with a ~lurality of openings 64
bein~ formed in the base member to provide communication
between the reverse osmosis module 32 and the waste water
passaqe 66 formed in the head me~er.
The elon~ated inlet tube 34 is connected to and is
in fluid communiation with the first tubular portion 38 of
the closure member. The tube 34 extends down into the
pressure vessel throu~h the reverse osmosis module and
provides in this case a fluid inlet passaqe into the bottom
Oe the associated pressure vessel 28.
The reverse osmosis module 32 includes a reverse
osmosis membrane 70 which in conjunction with a coextensive
grid member 72 is spirally wound, usually ;n several layers,
on a perforated tube 74 which ~referahly is made of plastic.
The ~lastic tube 74 is formed with many perforations alonq
its len~th to pass clean liquid therethrou~h. In the
assembly as herein shown the u~per end of the perforated tuhe
74 is sealin~ly attached to the closure memher 30 by seal 75
and is radially spaced from inlet tube 34 to provide
therebetween a circumferentially extendinq passaqeway 76.
The tube 74 also could be molded as one piece with closure
memher 30. This passaqeway 76 is adapted to receive the
purified water or other liquid bein~ processed which has been
forced throu~h the reverse osmosis member 70 under pressure
and from there it flows to the product water outlet 18 in
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head member as indicated hy the flow path 78 shown in a full
line.
A plu~ member 80 is disposed in the lower end of
tube 74, and inlet tube 34 extends tllrouqh plug member 80
being in sealed relation therewith. This arrangement is
effective to seal the inlet water flowin~ down through tube
34 fro~ contact with the processed product water enterinq
passa~eway 76 after passinq throu~h the reverse osmosis
me~brane 70.
Means are provided to create a chamber at the lower
end of the unit into which raw influent water will discharge
from inlet tube 34. In one manner of accomplishinq this a
cup like member 88 is sealin~ly attached to the lower end of
reverse osmosis module 32 with a rin~ seal member 90 being
disposed between the cup-like member 88 and the outer wrap 92
of the reverse os~osis module 32. This creates a chamber A
into which raw inlet water under line pressure flows from the
inlet tube 34. The water may continue its low upward under
pressure throuqh tlle laminations of module 32 as indicated by
the broken line flow path P. Durinq the course of this flow
some of the water is purified by removal of certain
undesirable ~ineral elements, and the pure water is forced
throuqh the membrane 70, then throu~h perforated tube 74 and
into passa~e 76 and out throu~h outlet port 18 in the head
memher 10 as indicated in part by the broken line flow path
P. Other means may be provided to create such a Chamber A.
For example, Chamber A could be created by sealin~ directly
to the pressure vessel 28 instead of usin~ the cup-like
member 88.
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Durin~ the course of water flow mineral impurities
are separated out because they cannot pentrate the module
membrane 70. These impurities settle on the membrane surface
and they are removed by water flowing along the surface of
the membrane and out throunh o~enin~s 64, Chamber s and waste
water outlet 20.
A capillary tube 98 may be disposed in the drain
line 100 which is connected to outlet port 20 in the head
member. The capillary tube serves to restrict the flow of
waste water throu~h the reverse osmosis module 32. Other
types of restrictions such as fixed orfices or flow controls,
which under certain circumstances may be more preferable,
also may be used to create this back pressure in Chamber B.
Such a restriction holds back most of the pressure and fluid
flow from Chamber B and allows only sufficient flow to flush
away the impurities which collect on the surface of membrane
70 and permit them to flow to drain.
While the operation of the reverse osmosis system
should be reasonably clear from the above description and
accompanyin~ drawin~s we now summarize the operation briefly.
Raw influent under line pressure enters inlet port 16 under
pressure and flows downwardly throu~h inlet port 16 and the
inlet tube 34 connected thereto into Chamber ~. Because the
influent water is pressurized it will move upwardly through
the laminations of the reverse osmosis membrane 70 to Chamher
B out to outlet port 20. At the outlet port 20 a restriction
or other means permits only limited flow and creates a back
pressure in Chamber B which is effective to force some of the
water flowin~ over the membrane 70 to penetrate through the
membrane 70 leaving behind on the surface of the membrane
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the dissolved solids and impurities and allowing the purified
water to enter Chamber C which is at a low pressure. The
pure water in Chamber C enters from the passaqe 76 between
the inlet tube 34 and the perforated tubular sleeve 74 upon
which the laminations of the module membrane 70 are wound.
The purified water then proceeds to the outlet port 1~ in the
head member.
When the membrane loses its ability over a period
of weeks, months or a year to effectively remove the
minerals, then it is time to chan~e the module. To
accomplish such chan~e out, a shut-off valve (not shown) is
closed to shut off line pressure. The pressure vessel 28
containinq the used membrane module and the integral closure
member 30 is removed from the head member 10. A new pressure
vessel with a new membrane module and its own integral
closure member then is inserted into the head member. The
shut-off valve is then opened and the system a~ain is ready
for operation.
It will be apparent that we have advanta~eously
provided an inte~ral disposable reverse osmosis unit which
may be quickly replaced as an entire unit thus eliminating
the necessity of dismantling the components of a pressure
vessel assembly to remove and replace a reverse osmosis
membrane module.
While a preferred embodiment of the invention has
been disclosed, it will be appreciated that this is shown by
way of example only, and the invention is not to be limited
thereto as other variations will be apparent to those skilled
in the art and the invention is to be ~iven its fullest
possible interpretation within the terms of the following
claims.
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