Note: Descriptions are shown in the official language in which they were submitted.
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METHODS AND DEVICES FOR TREATING WATER
TECHNICAL FIELD
This invention relates to devices and methods for treating
water comprising a dispensing device containing a composition of
tetraborate or tetraborate/boric acid and calcium hypochlorite
Ca(OCl)2. The method can be used for treating standing water
such as water in swimming pools, spas, cooling towers and the
like. The composition further comprises the alkaline metal
tetraborate and optionally, boric acid, mixed with calcium
hypochlorite,.
BACKGROUND OF THE INVENTION
In standing water, swimming pools, hot tubs and spas, it is
necessary to filter and recirculate water, add chemicals to keep
the water safe for bathing or free from algal growth, and remove
impurities. It is particularly important to keep standing waters
clean for safe use and free from growth of unwanted biological
organisms.
As a part: of basic pool and water maintenance, it is
frequently the case that the water is treated with halogen
chemicals, particularly chlorine and bromine. Some bodies of
water may be treated with chlorine gas which is dangerous and
difficult to use. There is always the danger of exposure of
humans or animals to the chlorine gas.
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For smaller bodies of water, chlorine is typically purchased
and used in the form of calcium hypochlorite granules which may
be mixed with water to form a liquid and then poured into the
swimming pool. Although such techniques of chlorine dispersion
and chemical treatment of water are widespread, there are many
disadvantages associated with these methods. In particular, the
chlorine is positioned and dispensed near the top of the pool
thereby making the treatment inefficient as chlorine evaporates
from the surface of the water at a high rate. Furthermore, the
process of mixing chlorine granules generally requires the use of
buckets and there is a substantial risk of splashing highly
chlorinated water, which can cause damage to clothing,
discoloration of surrounding areas such as ceramic tile or vinyl,
and physical irritation to lungs, eyes and skin due to the caustic
fumes.
Another problem associated with the distribution of
chemicals in swimming pools, hot tubs, spas and standing water
systems, is the actual handling of the chemicals themselves. Most
water treatment chemicals are present in granular or powder
form, and must be scooped, dissolved, and subsequently
distributed. Chemicals which are available in solid or block
forms must also be handled, and placed into appropriate devices
for distribution. It is generally not feasible to provide pool
chemicals or water treatment chemicals, especially chlorine, in
liquid form for simplified distribution as this may decrease shelf
life or storage options. Consequently, most individuals handling
pool or water chemicals must wear suitably protective clothing
such as gloves and protective eyewear. Such precautions make
chemical treatment of water both tedious and cumbersome.
Additionally, many water treatment chemicals are flammable and
must be stored to prevent accidental combustion.
Sodium tetraborate has long been known to be effective as
an algaecide and a fungicide in standing water systems such as
swimming pools, drinking water reservoirs, and cooling towers
and is the subject of U.S. Patent Nos. 4,594,091 and 5,131,938,
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both to Girvan, both of which may be referred to for finther details. It has
been found that the alkaline metal, tetraborate, by itself improves the
treatment
of standing water systems in several ways. The tetraborate solutions plus
dissolved carbon dioxide with produce sodium carbonate plus sodium
bicarbonate thereby lowering the CO2 concentration in the water and making
it difficult for algae to germinate in the water. The tetraborates have also
been
shown to react with dissolved halides in the water to give off free halogen.
Finally, the tetraborates increase the solubility of most other salts that may
be
added to the standing water system.
Another additive that is commonly used to treat standing water is
calcium hypochlorite. Calcium hypochlorite is added to water and, when
dissolved in water, provides a source of chlorine for disinfectant purposes
and
for general sanitation. Several commercial processes are currently used for
the
manufacture of the so-called "high-grade" calcium hypochlorite compositions
containing at least 65% calcium hypochlorite from which the chlorine for
sanitation purposes is derived. Several of these processes are described in
U.S.
Patent No. 3,793,216 which may also be referred to for further details.
The '216 patent discloses a calcium hypochlorite composition
comprising at least 55% calcium hypochlorite mixed with water soluble,
hydrated inorganic salts in an amount sufficient to provide a water content in
the total mixture in the range of about 3% to about 13%. Included in the
disclosure, as one of the hydrated inorganic salts, are the salts containing
tetraborate. The focus of the '216 patent is to reduce the flammability of the
calcium hypochlorite.
The major disadvantage of the essentially water-free
calcium hypochlorite compositions is the danger intended thereto
if contacted by external contaminants, which contamination causes
exothermic decomposition of the material regardless of the
temperature. For example, if any portion of a batch of said
calcium hypochlorite, whether in a small container, large drum or
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uncontained mass, reaches a temperature of about 350 F, it will
undergo a self-sustaining and self-propagating decomposition
which will spread through the entire batch until decomposition is
complete. Decomposition may be initiated by the accidental
touching of a live flame or spark to the calcium hypochlorite
composition, as for example, the accidental contact of a lit match
or cigarette. Decomposition may also be initiated by contacting
the hypochlorite with just a single drop of organic material, for
example, glycerin, and alcohol, a variety of hydrocarbons such as
petroleum oil and many others. The decomposition of all gaseous
chlorine which constitutes a toxic hazard to personnel in the area,
and also involves oxygen, which intensifies a fire that might reach
stored quantities of calcium hypochlorite. Because oxygen is
released in the decomposition process, attempts to smother a
hypochlorite fire will. be unsuccessful. The `216 patent thus
describes a composition which reduces the likelihood of
spontaneous decomposition of the calcium hypochlorite
composition. However, the `216 patent does not disclose any
other properties of a composition comprising calcium
hypochlorite and an alkaline metal tetraborate and/or boric acid.
What is needed in the industry is a method of distributing a
composition that will stabilize pH of the water, reduce the
presence of algae and other microorganisms which normally
grow in standing water, and provide a source of halogens which
will further sanitize the water solution. More particularly, what
is needed is an efficient and safe method of distributing water-
treatment chemicals whereby the chemicals are optimally utilized
and whereby unnecessary exposure of the chemicals to the persons
tending the body of water and the environment is minimized.
SUMMARY OF THE INVENTION
The present invention provides devices and methods for the
controlled administration of water treatment chemicals and
provides for the safe handling of chemicals. Chemicals such as
calcium hyp o chlorite/tetrab orate are packaged and shipped in
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5 sealed conveniently-sized containers. Particularly, the composition of Cdn.
Patent Application file 2,229,281 is suitable for use with the present method.
For use, one or more perforations are made into the container so that when the
container is immersed in water, the motion of the water and interaction with
the water, causes the chemical to dissolve and distribute into the water. The
number of perforations made into the container, together with the motion of
water, are coordinated such that the desired rate of chemical distribution is
achieved.
Surprisingly, when the composition of Cdn. Patent Application file
2,229,281, an admixture comprising an effective amount of calcium
hypochlorite and an effective amount of a mixture comprising borate salt and
boric acid, is used with the current invention, an unexpected advantage is
found in that the composition forms a solid briquette. The solid briquette
does
not immediately dissolve and flow into the water percolating through the
openings in the container. With many other kinds of water treatment
chemicals, the chemicals immediately dissolve into the water and thus too
much chemical is provided immediately and all of the chemical is gone in a
short amount of time. Instead, the briquette formed by the composition of
Cdn. Patent Application 2,229,281, in combination with the perforations in the
container, allows for the even distribution of the composition into the body
of
water.
A composition used with the present method is a calcium
hypochlorite/alkaline metal tetraborate composition or a calcium
hypochlorite/alkaline metal tetraborate/boric acid composition to
treat standing water systems such as swimming pools, spas,
cooling towers and the like. The method of treating water of the
present invention comprises the addition of the calcium
hypochlorite/tetraborate and/or boric acid composition to the
water periodically to stabilize pH and to increase the available
chlorine to the water. It has been found that the calcium
hypochlorite/tetraborate and/or boric acid composition act
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synergistically to reduce the growth of microorganisms in the water, reduce
the
cloudy scale on the sides of the water container that normally occurs when
only calcium hypochlorite is added to the water and reduces the calcification
of filters, especially sand filters.
The device of the present invention may be any convenient storage or
shipping container into which preselected openings can be made. Such a
device includes, but is not limited to, plastic or polymer bags which are
waterproof. The device may have a convenient appendage for anchoring the
container within the body of water.
A method of the present invention involves the creation of selected
openings in a sealed container that contains calcium hypochloritelalkaline
metal
tetraborate compositions or a calcium hypochlorite/alkaline metal
tetraborate/boric acid compositions. The container with the selected openings
is placed in a body of water, for example, a swimming pool. For a swimming
pool, a convenient site for placement is the skimmer. Upon placement in the
water, the composition within the container forms a solid briquette. The
selected openings allow the water to flow trough the container, across the
briquette, and the composition is evenly distributed into the swimming pool.
Treating water before the filter thereby allowing the chlorine residual to
last
longer with longer filter cycles.
Accordingly, the present invention seeks to provide a method for
treating standing water systems such as swimming pools, spas, and cooling
towers by administering a composition comprising calcium hypochlorite and
an alkaline metal tetraborate or calcium hypochlorite and a combination of an
alkaline metal hypochlorite and boric acid.
Further, the present invention seeks to provide a device for treating
standing water systems such as swimming pools, spas, and cooling towers by
administering a composition comprising calcium hypochlorite and an alkaline
metal tetraborate or calcium hypochlorite and a combination of an alkaline
metal hypochlorite and boric acid.
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Still further, the present invention seeks to provide a method for
treating standing water systems wherein a chemical is distributed by being
placed within a perforated device.
Further still, the present invention seeks to provide a device for
distributing a chemical in a body of water.
Moreover, the present invention seeks to provide a method for treating
standing water systems wherein the device for chemical distribution comprises
necessary perforations for a desired rate of chemical distribution.
Yet further, the present invention seeks to provide a device and method
for treating standing water systems wherein the device is placed or anchored
within a skimmer through which water circulates.
Still further, the present invention seeks to provide a method for
chemically treating standing water wherein the chemicals may be efficiently
utilized and safely handled.
Further still, the present invention seeks to provide a device comprising
chemicals for treating a standing body of water that can be safely handled and
provides less exposure to the chemicals within.
Yet further the present invention seeks to provide a device and method
for treating standing water systems wherein the device contains a calcium
hypochloride composition.
Moreover, the present invention seeks to provide a device and method
for treating standing water systems which will increase the availability of
free
chlorine to the system.
Further, the present invention seeks to provide a device and method for
treating standing water systems with a composition wherein the cloudiness of
the water is reduced.
Still further, the present invention seeks to provide a device and method
for treating standing water systems with a calcium hypochlorite solution
wherein the scale on the sides of the water container are reduced.
Another aspect of the present invention seeks to provide a device and
method for treating standing water wherein the normal cost of a calcium
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hypochlorite treatment of the standing water system is reduced.
Still another aspect of the invention seeks to provide a means by which
the advantages of water treatment chemicals can be made available in
relatively
small water systems.
Another aspect of the invention seeks to provide safe containers for the
storage and shipment of dangerous water treatment chemicals and to provide
child-proof containers for final consumer use.
Still another aspect of this invention is to provide a device and method
for using water treatment chemicals that is both simple and safe.
These and other aspects, features and advantages of the present
invention will become apparent after a review of the following detailed
description of the disclosed embodiments.
DETAILED DESCRIPTION
The present invention comprises devices and methods for
treating standing water systems with a composition comprising
calcium hypochlorite and an alkaline metal borate placed within a
distribution. Specifically, water treatment chemicals are
contained within a perforated device or container such as a plastic
bag. The container is then suspended, placed, or immersed into
the water dispensing equipment such as a pool skimmer.
Circulation of the water through dispenser or skimmer causes the
chemical to dissolve and disperse at a predetermined rate. The
rate of dispersion is controlled by varying the number of
perforations in the container. If necessary, the container may be
attached to the filter or skimmer by use of an anchoring device.
A preferred embodiment is a method and device which are
designed to dispense halogen sanitizer, such as Proteam
Calcibor, into a pool or spa on the suction side of the system. The
sanitizer within the bag is turned into a briquette when the bag,
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with predetermined openings being made into the bag, is placed
into the water. This is a surprising finding because if calcium
hypochloride alone, in a bag with openings, is placed into water,
the calcium hypochloride quickly dissolves and provides too much
chemical too quickly with no chemical provided at a later time.
The devices and methods of the present invention are
designed to dispense halides, blended with an erosion inhibitors,
in a briquette that forms immediately upon introduction to water.
The composition prior to introduction into water is a blended
powder-like composition. The container can provide distribution
of the chemicals without need for liners or reinforcement. A
single-walled plastic-type bag may have the sites for openings
printed on it.
The chemical distribution devices of the present invention
comprise containers capable of containing water treatment
chemicals, including, but not limited to, an admixture comprising
an effective amount of calcium hypochlorite and an effective
amount of a mixture comprising borate salt and boric acid. The
container is constructed of materials resistant to both destruction
from prolonged exposure to water and sunlight and to corrosive
and harsh substances such as chlorine. Such devices may be
constructed from plastic, nylon, rubber and the like. The devices
may be available in various shapes such as bags, hollow balls or
capsules, cylindrical tubes and boxes. Preferably, the shape and
size of the apparatus is determined by the equipment in which it is
to be placed. For example, in a water filter having very little free
area, the device may be a small, flexible plastic bag which is able
to fit into a confined space. For larger spaces such as in pool
skimmer baskets, the shape and size of the device would not be so
restricted.
The devices of the present invention have openings for the
exposure of the water treatment chemicals to the water
environment. Prior to placement in the water, the devices do not
have openings or any such openings are sealed or shut in any
manner known to those in the art. One embodiment would have
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the sites for the openings indicated by printed circles on the
container. Preferably, the devices have from 1 to 12 openings,
which are predetermined, in the device, more preferably, there
are from 1 to 8 openings, and most preferably, there are 2 to 8
5 openings in the device. A preferred device has the openings
indicated on the unopened device such that a consumer could
readily select the necessary number of openings, and open the
openings for optimum distribution of the composition to the body
of water.
10 The device may optionally be anchored or attached to a
particular area. For example, in a skimmer basket, it may be
attached to the basket by use of string or other appropriate
anchoring device such as hooks, clips, plastic coated wires, velcro
and the like.
A preferred embodiment of the invention comprises a
device such as a sealed, flexible, plastic pouch having enclosed
within it water treatment chemicals such as an admixture
comprising an effective amount of calcium hypochlorite and an
effective amount of a mixture comprising borate salt and boric
acid. The device has a number of sites for creating openings
printed on the pouch. A preferred method of the present
invention comprises determination of the total amount of water to
be treated, creating perforations in the pouch at the
predetermined, designated sites, and placing the device containing
the composition into a swimming pool skimmer basket. Upon
contact with water, the composition forms a briquette, which
gradually dissolves over a period of time, dispensing a
predetermined amount of chemical into the swimming pool at a
desired rate. Generally, as water is drawn past the briquette, the
motion of the water allows for uniform erosion of chemicals
from the briquette. The erosion is controlled by the rate of
dissolution of the briquette, the rate of flow past the briquette,
exposure of the briquette and the length of time the flow
continues. Once the briquette is substantially dissolved, the
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container simply floats to the surface of the skimmer, indicating
to the pool operator that a replacement is necessary.
The devices and methods of the present invention are
especially desirable because users do not have to handle the
chemical itself. Many water treatment chemicals are highly
corrosive, poisonous and dangerous, thus, eliminating the
possibility of the direct contact with such chemicals is particularly
advantageous. In addition, the invention is environmentally safe
in that it does not expose chlorine gas to the atmosphere as
unsealed containers of chlorine presently do. Also, the invention
comprises pre-measured amounts of chemicals, thereby
eliminating the added step of measuring out individualized
quantities for each periodic distribution with its inherent risk of
contact with the handler and the environment.
The devices and methods of the present invention are
further desirable because pre-packaged pouches containing
chemicals may be easily shipped, stored and distributed. In
addition, the devices are cost-effective and easy to use since no
complicated pumps, or motorized components are involved.
The borate in the composition is preferably an alkaline
metal tetraborate pentahydrate, an alkaline metal tetraborate
dehydrate an alkaline metal tetraborate pentahydrate. The
alkaline metal can be any alkaline metal that is compatible with
the borate ion. These alkaline metals include sodium, potassium,
and lithium. The composition that can be used in the method of
the present invention also includes a calcium hypochlorite and a
borate with boric acid. The combination of alkaline metal, borate
and the boric acid can be in the ratio of 5% to 95% borate to
boric acid by weight. In the composition for use in the method of
the present invention, the composition comprises between
approximately 60% and 80% calcium hypochlorite and between
approximately 20% and 40% of the borate molecule. Again, it is
contemplated that by the term borate molecule, as used herein, the
borate molecule can be any of the borate ions or it can be a
combination of the borate ion and boric acid.
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To prepare the calcium hypochlorite/borate composition,
the compositions are prepared by mixing the particular
ingredients uniformly in a powder blender that is, measured
amounts of the calcium hypochlorite with varying, measured
amounts of the borate salt and/or the boric acid combination. It is
important to note that the composition should be uniformly mixed
so that the resulting composition is a powder. The composition
can be further processed by compressing it into convenient tabs
that can be added to the standing water system. Methods of
producing these tabs are well known to those of ordinary skill in
the art. The calcium hypochlorite that is preferably used in the
present invention is commercially available and contains on the
order of at least about 65%, normally about 70-78%, and in some
cases up to 85% or more by weight of calcium hypochlorite, the
remaining constituents being sodium chloride, calcium chlorate,
calcium hydroxide, calcium carbonate and calcium chloride.
However, the products are always referred to in the trade as
"calcium hypochlorite."
The term "standing water system" includes, but is not
limited to, swimming pools, spas, hot water tubs, cooling tower
systems, foot baths, drinking water reservoirs and the like. The
present invention is contemplated as being used in any standing
water system wherein pH is desirably maintained at a stable value,
the growth of microorganisms is desirably inhibited, and the
clarity of the standing water system is desirably maintained.
In performing the method of treating water according to
the present invention, the calcium hypochlorite/borate
composition is administered to the water, that is the standing
water system at a final concentration of between approximately
0.5 to 10 pounds per approximately 10,000 gallons of water.
Preferably, the final concentration of calcium hypochloritelborate
composition is between approximately 1 and 3 pounds per 10,000
gallons of water. Most preferably, the concentration of calcium
hypochloritelborate composition is approximately 2 pounds per
approximately 10,000 gallons of water. For swimming pool
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treatment, the water is treated preferably between 1 and 7 times
per week. The method of treating standing water of the present
invention has several advantages over the use of calcium
hypochlorite by itself. As disclosed in the U.S. Patent No.
3,793,216, the composition of calcium hypochlorite with borate is
much less reactive when in contact with organic material and is
therefore much safer to use. However, it is not taught or
disclosed in the `216 patent that the composition comprising
calcium hypochlorite and borates allows one to use approximately
30% less calcium hypochlorite to obtain the same beneficial
effects as calcium hypochlorite alone, that the problems of water
cloudiness using calcium hypochlorite alone are reduced or
eliminated; that the normal problem of scale build-up on the sides
of the standing water container are reduced or eliminated; that the
calcification of water filters for the standing water system is
reduced or eliminated; and that the availability of free chlorine to
the standing water system is increased; and that the pH of the
standing water system is stabilized at more neutral pH then when
calcium hypochlorite is added to the water alone.
This invention is further illustrated by the following
examples, which are not to be construed in any way as imposing
limitations upon the scope thereof. On the contrary, it is to be
clearly understood that resort may be had to various other
embodiments, modifications, and equivalents thereof which, after
reading the description herein, may suggest themselves to those
skilled in the art without departing from the spirit of the present
invention and/or the scope of the appended claims.
Example I
A 12 ounce bag containing a composition of Canadian
Patent Application file 2,229,281, an admixture comprising an effec-
tive amount of calcium hypochlorite and an effective amount of a
mixture of a borate salt and boric acid, was added to a 10,000
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gallon pool. In order to deliver 1 ppm, 3 openings were made in
the bag.
When the bag was placed in the skimmer of the pool, the
composition immediately formed a hard briquette. Unlike other
pool treatment chemicals which quickly dissolve into the pool
water, the briquette is very stable and is maintained within the
bag.
The water in the pool was tested daily for the following
parameters:
Free and available chloride, pH, TA, CAH, CYA, TDS and
nitrates.
All tests results were in line with desired pool conditions.
After two weeks, the briquette had dissolved and the bag
was empty and floating. The bag was removed and another bag,
with the composition, was placed in the skimmer.
It should be understood, of course, that the foregoing
relates only to preferred embodiments of the present invention
and that numerous modifications or alterations may be made
therein without departing from the spirit and the scope of the
invention.
