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BACKGROUND OF THE INVENTION
The present invention relates to portable water purification systems and,
in particular, a water purifier orally operable by a human.
DESCRIPTION OF THE PRIOR ART
In an attempt to combat the high degree of impurities, contaminants, and
chemicals in most sources of drinking water, people have turned to the use
of water purification systems. Many large scale purifying systems have
been developed and perform the task adequately. However, one does not
always have access to water purified by a large scale purifier. Therefore,
portable water purifiers have been developed to allow a user to obtain
clean water wherever the person may go. Lightweight designs have been
achieved that allow oral operation and storage within a pocket of
clothing. Water purifiers of this type and others are disclosed, for
example, in the following U.S. Patent Numbers:
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Dyer 1,000,332
Crady 1,333,011
Pall 3,327,859
Barley 3,389,803
Sanzenbacher 3,392,837
Teeple 3,715,035
Lambert 3,923,665
Gartner 4,298,475
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Pall, Sanzenbacher, and Teeple disclose portable water purifiers having a
series of materials within a large structured container and include a
bacteria removal portion, activated charcoal or carbon, and other filter
means for a moving particulate matter. However, each of the structures are
so large as to prohibit discrete transport of the water purifier because
the device could not be carried on a person unobtrusively. Pall discloses
a generally rectangular box-like structure with a carrying case to retain
extending parts of the device and to protect the purifier. Sanzenbacher
discloses a large scale purifier also with a rectangular box-like
structure having several solid protrusions extending thereon, including a
handle for carrying the device and an outlet for obtaining the treated
water.
Teeple discloses a collapsible bag-like structure that requires the user to
hang the purifier for operation of the device and ultimately to obtain
treated water after the water drains through the purifier.
These structures present an impediment for unobtrusive portability of a
water purifier because they have structures with protrusions. Furthermore,
these devices require steps to be taken by the user before the
purification process can begin: either pouring water into the device or
unpacking the device from a protective case designed to retain the
protrusions.
In response to the shortcomings of larger-scale portable water purifiers,
straw-like pocket purifiers have been developed. Dyer, Crady, Barley, and
Gartner disclose structures having a filtering material, including
activated charcoal or carbon, and a bacteria removal material. The
structures allow transportation or storage of the device within a pocket
of clothing or other personals.
Dyer and Crady disclose straws that have multiple parts cooperable with one
another to allow disassembly and assembly of the device. Crady shows a
straw having two parts which releasably engage each other by means of
cooperable screw threads placed on each part of the straw. Dyer also
discloses a two-part straw whereby a filter part releasably engages the
other part of the straw by means of a cooperable screw thread, the other
part also including a telescopically collapsible mouthpiece portion. In
order to purify drinking water, this design requires the user to assemble
the straw from an inoperable storage position. Both Dyer and Crady also
allow the replacement of the filtering material, such as activated
charcoal, by permitting the removal of screens located within the straw
through the disassembly of the straw.
Barley discloses a one-piece pocket straw which contains a bacterial filter
between two screens, a filter plate, activated carbon, and another filter
plate. Gartner discloses a one-piece pocket straw that contains the
bacteria removal material as a first step in treatment of the water
followed by activated carbon as the last step in treatment of the water.
Filter means are positioned before the bacterial removal resin, between
the activated carbon and the bacteria removal material, and after the
activated carbon. However, neither Gartner nor Barley permit the
replacement of the particulate filter plate or the filter means,
respectively, and Crady and Dyer require some disassembly of the straw to
replace the filtering material enclosed therein. Furthermore, neither
Gartner nor Barley provide a mechanism to insure that the activated carbon
is maintained in a uniform structural state, and that both the carbon and
mouthpiece remain free of saliva-borne or air-borne bacteria.
Lambert also discloses that a demand bactericide, such as a strong base
anion exchange resin containing triodide, may be used as a bacteria
removal agent to kill bacteria without leaving significant amounts of
residual iodine in the treated water.
There is a continuing need for improved orally operable portable water
purifiers. The purifier should be designed so that it may be readily
carried unobtrusively in a pocket and available for direct use without any
assembly. Furthermore, the device should permit the quick removal and
exchange of an initial particulate filter without disassembly of the
device. This capability will thereby reduce the cost of using a pocket
purifying system because the whole straw need not be replaced when the
particulate filter becomes occluded. The design should include a powerful
bactericide to kill or remove all organic matter and other harmful
bacteria. It is also desirable to include an activated carbon material and
maintain the carbon in a uniform structural state to ensure proper
adsorption of taste and odor contaminants and to ensure removal of the
iodine from the water. In addition, the device should be designed so that
an additional bactericide operates on the water after the carbon stage to
provide a residual level of iodine in the water to prevent airborne
bacteria and saliva-borne organisms from growing in the activated carbon
material, as well as keeping the mouthpiece free from similar
contamination.
SUMMARY OF THE INVENTION
The present invention is an orally operable portable water purifier which
removes contaminants and bacteria from ordinary water to provide suitable
drinking water. The water purifier comprises a straw which purifies the
water by forced movement of the water through the straw. The straw
includes an elongated tubular conduit with an inlet at a distal end of the
conduit and an outlet at a proximal end of the conduit, with an inlet
filter removably mounted at the distal end of the conduit. Proximal to the
filter is a purification material, an activated carbon material, and a
bactericide material in series. A plurality of porous spacers are
positioned selectively within the conduit as follows: a first spacer
between the filter and the purification material; a second spacer between
the purification material and the carbon material; a third spacer between
the carbon material and the bactericide material; and a fourth spacer
proximal to the bactericide material. A tubular mouthpiece is mounted to
the proximal end of the conduit.
In a preferred embodiment of the present invention, the straw also includes
resilient foam layers positioned at opposite ends of the carbon material
to permit expansion of the activated carbon. Moreover, the pore size of
the inlet filter is smaller than the pore size of the porous spacer or the
foam layer, and the pore size of the foam layer is larger than the pore
size of the porous spacer. The inlet filter is frictionally inserted
partially within the inlet of the conduit and has a slightly compressible
retention ring surrounding the filter and of size to frictionally engage
an inner surface of the conduit. The purification material is a pentacide
resin, the carbon material is a granular activated carbon, and the
bactericide material is a triocide resin, all of which are known
materials. The porous spacers are a porous plastic.
The purifier, in accordance with the present invention, is small, and
unobtrusively carriable in a pocket. The inlet filter is quickly removable
allowing an occluded particulate filter to be quickly exchanged for a new
filter without any required disassembly of the straw. Furthermore, the
initial bactericide purification material, in combination with the
activated carbon, and the final bactericide stage produce a final product
of drinking water suitable for consumption and that also maintains the
carbon and mouthpiece in an anti-bacterial state.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a longitudinal sectional view of the water purification straw
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention of a water purification straw is illustrated
generally at 10. The straw 10 includes an elongated tubular conduit 12,
which has an inlet 14 at a distal end 16 and an outlet 18 at a proximal
end 20. The conduit 12 also has an inner surface 22 and an outer surface
24. The conduit 12 is made preferably of a polycarbonate material and is
preferably circular in cross section.
A removable inlet filter 26 is positioned within the inlet 14 and has a
neck 28 and a head 30, joined by shoulder 32. A retention ring or sleeve
36 is also positioned within the inlet 14 and has an outer surface 38, an
inner surface 40, and a lip 42. The outer surface 38 of ring 36
frictionally engages the inner surface 22 of conduit 12 and the lip 42 of
ring 36 abuts the distal end 16 of conduit 12 to further constrain the
ring 36 relative to the conduit 12. The neck 28 of filter 26 frictionally
engages the inner surface 40 of ring 36 and is partially inserted within
the inlet 14 such that ring 36 surrounds the neck of filter 26. The
shoulder 32 of head 30 abuts lip 42 of ring 36 to further constrain
movement of the filter 26 relative to the conduit 12 and ring 36. The ring
or sleeve 36 is made of a slightly compressible material to provide a
friction fit for the filter.
The inlet filter 26 is a removable and is used for removing particulates
and sediment from the water. The filter 26 is made preferably of a porous
plastic and preferably has a pore size of about 80 microns, for example.
The retention ring 36 is made preferably of a polycarbonate material.
A first porous spacer 44 of a plurality of porous spacers, which are
positioned within the conduit 12, is positioned proximally adjacent to the
ring 36 within conduit 12. The spacer 44 is a disk that firmly engages the
inner surface 22 of conduit 12. The first spacer 44 is made preferably of
a porous plastic and preferably has a pore size larger than the pore size
of the removable inlet filter 26. A preferable pore size for the first
spacer 44 is 140 microns. The spacer 44, in combination with other spacers
within the conduit 12, aid in keeping the various materials within the
conduit 12 segregated appropriately.
A purification resin 46 is filled within conduit 12 between the first
spacer 44 and a second porous spacer 48. The purification resin 46 acts to
kill nearly all bacteria, and organic materials or organisms that are
present in the water being subject to treatment. The purification resin 46
is made preferably of a pentacide resin, such as the pentacide resin
obtainable through Water Technologies Corporation, the assignee of this
application. The resin can be any suitable bactericide.
A first resilient foam layer 50 is positioned proximally adjacent to the
second spacer 48 on a side of the spacer opposite from the resin 46.
Activated carbon granules 52 are filled within the conduit 12 between the
first resilient foam layer 50 and a second resilient foam layer 54. The
activated carbon 52 acts as an adsorptive media to remove taste and odor
contaminants, as well as reduce the residual iodine level in the purified
water resulting from the action of resin 46.
The foam layers 50 and 54 act as expansion joints to prevent channeling of
the carbon 52 and to allow the carbon 52 to expand permitting even flow of
the water. The foam layers 50 and 54 have a pore size larger than the pore
size of the inlet filter 26 or the porous spacers. A preferable pore size
for the foam layers 50 and 54 is 240 microns. The foam layers 50 and 52
are preferably disks, which fit firmly within the conduit 12.
A third porous spacer 56 is positioned within the conduit 12 proximally
adjacent to the foam layer 54. A bactericide resin 58 is filled within the
conduit 12 between the third porous spacer 56 and a fourth porous spacer
60, which is positioned within the conduit 12 at the proximal end 20. The
bactericide resin 58 is preferably a triocide resin and acts to prevent
the entry and growth of air-borne bacteria and saliva-borne organisms
within the activated carbon material 52 and a mouthpiece 62.
The mouthpiece 62 is mounted at the proximal end 20 of conduit 12 and has a
securing end 64, a user end 66, and an inner surface 68. The inner surface
68 of mouthpiece 62 is mounted to the outer surface 24 of conduit 12. The
securing end 64 engages the proximal end 20 and outer surface 24 of
conduit 12, whereas the user end 66 is adapted to be received within the
mouth or orifice of the straw device user. The mouthpiece 62 is made
preferably of a polycarbonate or polypropylene material.
In operation, the straw device 10 is held by the user so that the distal
end 16 and the inlet filter 26 are immersed within the water to be
purified. Oral suction is applied by the user at the mouthpiece 62 to
forcibly move the water through the conduit 12 from the inlet 14 to the
outlet 18. As the water moves through inlet filter 26 after entering at
head 30, most heavy particulate matter and sediment material is removed
from the water by filter 26. Next, the filtered water passes through the
first porous spacer 44 into the purification resin 46, such as a pentacide
or strong bactericide. The pentacide resin 46 is the primary purification
stage that acts to kill all bacteria, organic matter including
microorganisms, and other contaminants within the water.
As the water passes further through the straw 10, it flows through second
porous spacer 48 and then the first foam layer 50, followed by activated
carbon 52. The activated carbon 52 is directed primarily at improving the
taste of the purified water by acting as an adsorption medium to remove
taste and odor contaminants in the water, as well as reducing the residual
iodine level in the purified water that results from treatment by the
purification resin 46. The granules of carbon 52 are permitted to expand
and are maintained in a uniform structural state by slight compression
forces from the resilient foam layers 50 and 54. The carbon particles are
thus held from shifting laterally to avoid forming channels which permits
untreated water to flow through the carbon section. The water is treated
uniformly at an efficient rate.
Finally, the water moves through a third porous spacer 56 into the
bactericide resin 58 which is the final treatment stage, and out through a
fourth spacer 60, through the mouthpiece 62 into the user's mouth. The
bactericide resin 58 primarily acts to prevent bacteria and organisms,
which originate from the user's mouth or the surrounding environment, from
entering the straw 10 through the mouthpiece 62 to contaminate the carbon
52 and the mouthpiece 62. The bactericide resin 58 contains a bactericide
weaker than that of resin 46, and accomplishes the cleansing task by
reintroducing a residual level of iodine into the water, such that
bacteria are killed, but without unduly tainting the taste of the purified
water. Thus, ordinary water is moved from the inlet 14 of the straw 10 to
the outlet 18 of the straw 10 to provide a purified, clean and tasteful
water product for the user.
The water purification straw 10 has considerable advantages over those of
the prior art. The filter 26 is removable from the straw 10 and is
replaceable so that the primary particulate filter 26 may be exchanged
when the filter 26 becomes occluded. Thus, the entire straw 10 need not be
disposed of when the particulate inlet filter 26 becomes plugged. This
yields a cost savings to the user while allowing the straw 10 to be
maintained at peak efficiency. The purification straw 10 has a lightweight
design and low profile such that it may be carried within a pocket or
personals in an unobtrusive fashion. Straw 10 does not require any
assembly or disassembly for its use, or for removal and exchange of the
filter 26. The foam layers 50 ensure that the activated carbon 52 will be
maintained in a uniform structural state to permit efficient treatment of
the purified water. The straw 10 also includes the use of a strong
bactericide as a purification material 46 which is similar to that of the
prior art. However, the straw 10 has an additional bactericide resin 58
following the carbon 52 which acts to keep the straw 10 free of user
originated bacteria and organisms, thereby prolonging the useful life of
the activated carbon 52 and straw 10. This last step also keeps the
mouthpiece free from contamination without unduly hampering the taste or
effectiveness of the purification process.
Suitable caps can be placed over the inlet filter and the mouthpiece when
the straw is not in use, as is well known. Although the present invention
has been described with reference to preferred embodiments, workers
skilled in the art will recognize that changes may be made in form and
detail without departing from the spirit and scope of the invention.
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