WO1997036826A1

WO1997036826A1 - Method and device for reducing formation of salt deposits in fluid use systems

Info

Publication number: WO1997036826A1
Application number: PCT/IL1997/000110
Authority: WO
Inventors: Michael Cais; Haim Yarnitzki
Original assignee: Silk Water Technologies Ltd.
Priority date: 1996-04-02
Filing date: 1997-03-26
Publication date: 1997-10-09
Also published as: AU2041697A; IL117781A0

Abstract

In a method for preventing mineral salt deposits in fluid use systems, a device (10) has a capsule body (12) with walls (14, 16, 18) defining a chamber (20). The capsule body (12) is insertable in a fluid pipeline (24) so that the chamber (20) communicates on an upstream side and a downstream side with the pipeline (24). The capsule chamber (20) contains a multiplicity of spherical particles (22) made of composition enabling electron transfer. Specifically, the particles (22) are made of an alloy with basic components taken from the group consisting of copper, tin, zinc, nickel, and iron. At least 65 % of the sphere's (22) composition is copper with the other basic elements being present in the alloy in an amount by weight of 5-7.5 %.

Description

METHOD AND DEVICE FOR REDUCING FORMATION OF SALT DEPOSITS IN FLUID USE SYSTEMS

Background of the Invention

This invention relates to the field of fluids use and particularly water use More

specifically, this invention relates to a method and an associated device for preventing the formation of mineral salts deposits in fluid use systems The method and device also assist in the removal of previously formed deposits

Water which is transferred by pipeline for industrial or residential use frequently

contains anions such as HCO₃ ^1", CO₃ ^2", OH^1", SO₄ ^2", PO₄ ^3' , and SiO₃ ^2' and cations such as Ca²⁺,

Mg²⁺, Fe ⁺, Fe³⁺, Al³\ and Zn²⁺ which lead to the deposition of mineral salts specifically in the

pipelines and more generally in water provisions systems Calcium carbonate, CaCO₃, is the

most common salt deposited in water use systems "Scaling" is the term normally used with respect to deposition of a solid whose solubility is decreased

Mineral deposits, particularly salt deposits are undesirable in pipelines and water use systems because of eventual diminution of flow and system capacity, as well as possible

electrolytic damage to the metallic components A known method for the prevention of salt deposits is acidification of the water through the addition of H₂SO₄ or HCl Other known

methods include recarbonation (CO₂ gas) and the addition of polyphosphates (NaPO₃)₆ and

Na₅P₃O₁₀

Yet another method for the prevention of salt deposits comprises the passing of water

through a layer of granulated ion exchanger In this process, cation ions are exchanged for

Ca²⁺ and Mg²⁺ ions Sodium, hydrogen and ammonium ions are distinguished here

Further methods for preventing the deposition of salt deposits on conduit surfaces include the application of magnetic fields, which retard the deposition process, or passing the water through various metal input devices on which mineral salts are reduced.

A number of devices have been developed in order to stabilize the flow of water through a pipe by decreasing, to a certain extent, the formation of scale. However, the results

obtained show that the beneficial effect which was achieved is only temporary.

U.S. Patent No. 3,486,999 discloses a device comprising an anodic core of a self

sacrificing metal, which decomposes over a long period of time. As pointed out in this patent, a chemical decomposition reaction is involved between the core and the water which minimizes

scale formation.

According to U.K. Patent No. 2,127,581, a device inserted in a conduit through which water is passed consists of longitudinally extending baffle spans and a plurality of venturi means on opposite surfaces, thus forming a series of flow channels. The water passing through

the device is subjected to a turbulent flow which reduces, to a certain extent, the tendency of

the water to form scale in the respective conduit.

U.S. Patent No. 3,636,983, cited in the above-discussed U.K. patent, describes a

method and device for increasing fluid flow. The device is a venturi type nozzle, provided with

baffles which cause an increase in the rate of flow.

Pursuant to U.S. Patent No. 3,448,034, a device for stabilizing liquids, such as water,

serves to avoid, to a certain extent, the precipitation of undesirable substances, such as calcium

sulfate, sodium salts and other destructive minerals, which are injurious to the flow tubes. The device includes a metallic rod of a particular composition of nonferrous metals, copper being

the main constituent, having a polarizing effect on the water to eliminate any affinity with the

mineral substances therein. The metallic rod is enclosed within a flow tube through which the

water is conveyed. It is apparent that the formation of scale in a conduit through which water is passed is a serious problem Various solutions have been proposed beginning as early as 1966. However, up to now there is evidently no device which provides a real solution to the critical problem of

scale deposition in the interior of a conduit through which water is passed.

Objects of the Invention

An object of the present invention is to provide a method and/or a device for reducing,

if not preventing, the deposition of mineral salts in fluid use systems.

Another object of the invention is to provide such a method and/or device which is

inexpensive and reliable and does not require human intervention upon installation.

It is a further, specific object of the present invention to provide such a device which,

when inserted in a fluid or water pipeline, provides a substantial or increased duration of liquid

contact with an activating surface.

Yet another object of the present invention is to provide such a device which is flexible in installation and can be connected with virtually any mechanical filter

These and other objects of the present invention will be apparent from the descriptions

and drawings herein.

Summary of the Invention

A method for inhibiting scale formation on the walls of a conduit through which a fluid

is passed, where the fluid includes dissolved constituents, comprises, in accordance with the

present invention, (a) guiding the fluid through a chamber containing a plurality of small

particles made of a composition enabling electron transfer and (b) during the guiding of the fluid through the chamber, inducing generation of an electric field in the fluid by virtue of the

particles, the electric field being sufficient to cause modification of nucleation patterns of the fluid, thereby causing an inhibition of essential nucleation steps in the fluid which precede and

govern scale formation.

The particles are preferably made of a metal alloy comprising more than 65% copper and possibly containing a small amount of an element taken from the group consisting of

nickel, zinc, and stanium, as well as minor constituents selected from the group consisting of iron, lead, aluminum, manganese and noble metals

Preferably, the particles have a total surface area of at least 150 square centimeters A device for preventing mineral salt deposits in water use systems comprises, in

accordance with the present invention, a capsule body having walls defining a chamber, the

capsule body being insertable in a fluid pipeline so that the chamber communicates on an

upstream side and a downstream side with the pipeline The capsule chamber contains a

multiplicity of particles made of a composition enabling electron transfer

Specifically, the particles are made of an alloy with basic components taken from the group consisting of copper, tin, zinc, nickel, and iron The alloy further includes auxiliary components taken from the group consisting of silver, manganese, silicon, gold, and carbon and attendant components taken from the group consisting of phosphorus, sulfur, magnesium,

aluminum, vanadium, tungsten, molybdenum, and cobalt Preferably, at least 97% of the alloy

by weight is composed of the basic components, with at least 65% of the alloy by weight being

composed of copper Other selected basic components are present in the alloy in an amount by

weight of 5-7 5% Each auxiliary component, if present, occurs in an amount by weight of

0.1-0 2%, while any one attendant component occurs in an amount by weight of 0.01-0 02%

Preferably, the alloy includes selected auxiliary components and selected attendant components

in an aggregate amount by weight of less than approximately 2 5% Other, polluting elements are present in a total amount of less than about 0.5% by weight.

Preferably, the particles are spherical in order to provide an optimal surface area for

contact with the flowing liquid.

Generally, each of the particles is in contact with at least one other of the particles and

at least some of the particles are in contact with the walls of the capsule body.

To provide additional surface area for electric field generation in the moving fluid and,

concomitantly, electron transfer, the capsule body itself may be provided internally with

formations for increasing the available surface area. In accordance with this feature of the invention, the walls of the capsule body define a first chamber communicating on an upstream

side with the pipeline and a second chamber communicating on a downstream side with the pipeline, and at least one of the walls, disposed between the first chamber and the second

chamber, is provided with a plurality of apertures through which fluid flows from the first

chamber to the second chamber, that perforated wall being made, at least in regions including

the apertures, of a composition enabling electron transfer. In a specific embodiment of the

invention, the first chamber is an inner chamber disposed inside the second chamber and the

apertures in the perforated wall are star shaped.

A device in accordance with the present invention serves to reduce, if not eliminate, the deposition of mineral salts in water use systems, including pipes and other transfer conduits.

The device prevents new salt deposits and also assists in the removal of previously deposited salt layers.

A device in accordance with the present invention is inexpensive and reliable. The

device is easy to use because once it is installed, it operates without human intervention.

A device in accordance with the present invention provides a substantial or increased duration of liquid contact with an activating surface. The activating surface is mainly the collective surfaces of the spherical particles.

A device in accordance with the present invention is flexible in installation and can be connected with virtually any mechanical filter. An optimal result is obtained when the water

treatment device in accordance with the invention is used in conjunction with and specifically

downstream of a mechanical filter. The filter removes insoluble salts and other mineral

elements by the mechanical filtering process and accordingly these insoluble salts and other

mineral elements do not reach the water treatment device of the invention, which increases the

efficiency of treatment in the capsule.

Brief Description of the Drawings

Fig. 1 is a schematic side elevational view of a water treatment device for preventing mineral salt deposits in water use systems, in accordance with the present invention, showing

the device inserted, together with a conventional filter, in a water conducting pipeline.

Fig. 2 is a schematic axial or longitudinal cross-sectional view, on a larger scale, of the

water treatment device of Fig. 1.

Fig. 3 A is a longitudinal cross-sectional view of another water treatment device for

preventing mineral salt deposits in water use systems, in accordance with the present invention.

Fig. 3B is a transverse cross-sectional view taken along line IIIB-IILB in Fig. 3A.

Fig. 3C is a transverse cross-sectional view taken along line IIIC-IIIC in Fig. 3 A. Fig. 3D is a partial side elevational view of a tubular wall in the water treatment device

of Fig. 3 A, showing in detail a star-shaped aperture in the tubular wall.

Fig. 4 is a perspective view, partially broken away, of the water treatment device of

Fig. 3A. Fig. 5 is a schematic side elevational view, partially broken away, of a water treatment

device in accordance with the present invention, together with a conventional disk filter.

Fig. 6 is a schematic side elevational view, partially broken away, of a filter with a water treatment device in accordance with the present invention disposed inside the filter. Fig. 7 is a schematic side elevational view, partially broken away, of a filter with a

water treatment device in accordance with the present invention disposed in a liquid outlet of a

mechanical self-cleaning disk filter.

Description of the Preferred Embodiments

As illustrated in Figs. 1 and 2, a water treatment device 10 includes a housing or

capsule body 12 having a water permeable upstream wall 14, a water permeable downstream wall 16 and a cylindrical peripheral wall 18. Walls 14, 16, and 18 define a cylindrical electron

transfer chamber 20 in which a multiplicity of spherical particles 22 are disposed. Generally,

particles 22 are each in contact with at least one other of the particles and at least some particles 22 are in contact with walls 14, 16 and 18. Particles 22 are made of a composition enabling electron transfer during the flow of water through chamber 20. Specifically, particles 22 are made of an alloy with basic

components taken from the group consisting of copper, tin, zinc, nickel, and iron. The alloy

further includes auxiliary components taken from the group consisting of silver, manganese,

silicon, gold, and carbon and attendant components taken from the group consisting of

phosphorus, sulfur, magnesium, aluminum, vanadium, tungsten, molybdenum, and cobalt.

Preferably, at least 97% of the alloy by weight is composed of the basic components, with at

least 65% of the alloy by weight being composed of copper. Other selected basic components are present in the alloy in an amount by weight of 5-7.5%. Each auxiliary component, if present, occurs in an amount by weight of 0 1-0.2%, while any one attendant component

occurs in an amount by weight of 0 01-0.02% Preferably, the alloy includes selected auxiliary

components and selected attendant components in an aggregate amount by weight of less than

approximately 2 5% Other, polluting elements may be present in a total amount of less than about 0 5% by weight

Generally, the alloy material of spherical particles 22 is made by melting together, in a

chemically inert crucible, raw materials composed of the basic elements The auxiliary and the

attendant elements, as well as any pollutants pass into the composition by virtue of being

present in small amounts in the raw basic components It is to be noted that any alloy composition with components falling within the above

weight ranges is expected to result in salt deposition reduction or elimination in water use

systems

As further illustrated in Fig 1, capsule body 12 is inserted in and connected to a water

pipeline or conduit 24 downstream of a conventional granular or activated carbon filter 26 which has an inlet 28 and an outlet 30 As further illustrated in Fig. 2, upstream wall 14 and downstream wall 16 are provided with respective apertures or throughholes 32 and 34 enabling

water to flow through capsule body 12, as indicated by arrows 36 and 38

In one specific realization of the water treatment device 10, spherical electron transfer

particles 22 had the following composition Cu - 70%, Ni - 8%, Sn - 6 5%, Zn - 8%, Fe -

2 5%, Au - 0.05%, Al - 0 5%, Mn - 0.5%, and Ag, Pt, C, SO₄ each less than 0 05%, with the

total content of other minerals at 3.95% The device 10 was placed in a 1 1/4" (32 mm) pipe

24 Water flow through capsule body 12 was 1000 liters (250 gallons) per hour with a water pressure of 2-2 5 kg/cm² The mineralization level was 350-400 mg/1 The basic impurities in the water determining the formation of hard salts were Ca²⁺, Mg²⁺, and Fe³⁺. Capsule chamber

20 contained 150-250 particles 22 which had a diameter of 4-10 mm. Capsule body 12 had a

diameter of 32 mm and distance between upstream wall 14 and downstream wall 16 of 17 cm. As illustrated in Figs. 3A and 4, another water treatment device 40 operating according

to electron transfer principles as discussed herein comprises a capsule body 42 including an

inner tubular member 44 coaxially surrounded by a second tubular member 46 in turn coaxially

surrounded by a third tubular member 48. Inner tubular member 44 communicates with a

conduit or pipeline 50, while outer tubular member 48 is connected to a conduit or pipeline 52. Generally, it is contemplated that water containing multiple ions and other constituents flows into capsule body 42 via inner tubular member 44, as indicated by arrows 45, and exits the capsule body via outer tubular member 48, as indicated by arrows 47.

Inner tubular member 44 is closed at one end by a plate or planar wall 54 and is

provided in a cylindrical sidewall 56 with a plurality of perforations or apertures 58 enabling

fluid flow (arrows 59) from inner tubular member 44 into the middle tubular member 46.

Tubular member 46 has solid end plates or planar walls 60 and 62 and a cylindrical sidewall 64 formed with a multitude of perforations or apertures 66 for enabling fluid flow (arrows 61) from the middle tubular member 46 into outer tubular member 48. Apertures 58 in inner tubular member 44 and apertures 66 in middle tubular member 46 are arranged in

longitudinally staggered planes (see Figs. 3 A, 3B, 3C).

Cylindrical sidewalls 56 and 64 of tubular members 44 and 46 are made of a

composition enabling electron transfer, at least in regions about apertures 58 and 66. The

composition is the same as that described above with respect to particles 22.

Apertures 58 and 66 can have any shape, for instance, circular, as illustrated in Figs. 3 A and 4 However, it is preferred that apertures 58 and 66 are formed to maximize the total surface area through which water flows from one tubular member to another A star shaped

design 41, as illlustrated in Fig 3D, is particularly effective

Apertures 58 and 66 have a diameter of at least 0 5 cm Generally, the diameters of apertures 58 and 66 depend on the thicknesses of cylindrical sidewalls 56 and 64 The

controlling consideration is the surface area available for electron transfer during motion of

water from inner tubular member 44 into chamber 68 and from chamber 68 into outer tubular

member 48 Generally, apertures 58 and 66 must present a total of at least 150 square

centimeters of area to the moving fluid Tubular members 44 and 46 together define a cylindrical chamber 68 To further enhance the electron transfer capabilities of device 40, chamber 68 may contain a multiplicity

of spherical particles 69 Generally, as discussed above with reference to Figs 1 and 2,

particles 69 are each in contact with at least one other of the particles and at least some

particles 69 are in contact with sidewalls 56 and 64 or end walls 54, 60, and 62 Particles 69

are made of a composition as discussed above for enabling electron transfer duπng the flow of

water through chamber 68 Particles 69 and apertures 58 and 66 together implement electron

transfer to inhibit scale formation and together must present a surface area of at least 150

square centimeters to the moving water to effectuate electron transfer

The lengths of tubular members 44, 46, and 48, depends on the required surface area for providing a sufficient electric field as well as on the respective location thereof Of course,

one may also use two or more tubes, located one after the other, depending on the amount of

the dissolved constituents as well as on the available space According to another embodiment, it is also possible to use any combination of the two types of tubes illustrated in Figs. 1, 2 and 3 A, 4. The preferred embodiment, will depend on the particular type of the fluid

and its dissolved constituents.

Fig. 5 shows a water treatment device 70 as described hereinabove with reference to

Figs. 1 and 2 disposed in a water use system (not shown) downstream of a conventional disk filter 72. Arrows 74 indicate a direction of water flow from an inlet 76 of filter 72, through

filter disks 78 and 80, to a filter outlet 82 connected to device 70.

Fig. 6 shows a water treatment device 84 disposed inside a filter 86. Water flows at 88

into a filter inlet 90 and then through a perforated cylindrical side wall 92 of device 84, as

indicated by arrows 94. Water exits from an internal chamber 96 of device 84 through a

passageway 98 in filter 86. The treated and filtered water leaves filter 86 through an outlet side 100, as indicated by an arrow 102.

Fig. 7 shows a mechanical self-cleaning disk filter 104 with a water treatment device

106 disposed in a liquid outlet 108 of the filter. Water enters an inlet 1 10 of filter 104 and is

guided through a manifold 1 12 to filter disks 1 14. Upon passing through disks 1 14, the water passes into liquid outlet 108 and water treatment device 106. Device 106 has a form described

hereinabove with reference to Figs. 1 and 2.

An optimal result is obtained when a water treatment device as described herein is used

in conjunction with and specifically downstream of a mechanical filter. The filter removes

insoluble salts and other mineral elements by the mechanical filtering process and accordingly

these salts and other mineral elements do not reach the water treatment device of the invention,

which increases the efficiency of treatment in the capsule.

The solutions described hereinabove to the problem of scaling in water use systems are

based on a thorough theoretical investigation of the problem. In that investigation, it was found that the inhibition of scale is related to an electrical double layer which is formed at the

interface of a moving fluid and the metal surfaces of a conduit or pipeline through which the

fluid moves Thus, the stability of the metals in a fluid depends on the various constituents

which are present in the solution In the simplest case, when no oxygen is present and an inert electrolyte is dissolved in a fluid and therein dissolved constituents, the charge of an electrode

immersed in a fluid is virtually zero In this case, it is practically impossible to measure the

potential of the electrode versus same point in the bulk of the fluid, but such measurement

could be carried out by means of a reference electrode The reference electrode would

introduce an additional and constant potential difference which is not measurable Thus,

assuming the charge on the electrode to be zero, the actual measured potential will be called a

potential zero charge (PZC) Assuming the metal electrode to be charged by some electrical

pump, the electrode will acquire some potential which will differ from the PZC, being either

positive or negative The potential difference which arises from the charge injected and the

counter charge - of the opposite sign - will result from that accumulated near the electrode surface The two layers of opposite charge, constitute the "double layer" which can be simulated by a simple electrical capacitor The distance between the two layers is of the order

of 1/10 of a nanometer The potential across the double layer can be changed by 1 volt in relation to the PZC Therefore, the electric field between the two layers, will be in the order of

10¹⁰ Vm^"1 This electric field is very strong, which explains why electrons are mobile, being transferred from the electrode to a species in the solution, or vice versa, depending on the

direction of the field The discharging ions, that exchange electrons with the electrode, will

approach the electrode surface causing them to bend and remove their hydration shell This

process does occur instantly when the ions enter the extensive electric field. As mentioned above, the charging can be carried out by a power supply, such as an electric pump. However,

there are metals such as zinc which can react and release electrons, if the potential is set to the

PZC, as measured in the case of a noble metal such as platinum, gold, etc.

When the electrode is not connected to the same electron sink, the released electrons

will charge the double layer until a negative potential, compared with PZC, is reached. As a

result, the electrode will be negatively charged and as a consequence, an electric field across the double layer is established In this case, several processes might occur.

( a ) An electron transfer to some species as present in the solution A typical example of this case is the dissolved oxygen, which will consume the electrons released by a metal, such

as zinc, and will maintain the potential at positive values. The metal will be spoiled completely, at the rate which will be equivalent to the oxygen supply This process is well-known as

corrosion

( b ) The negatively charged electrode will release electrons as "hydrated electrons".

This process, depends on the type of the metal immersed in the solution It is generally

accepted that a relatively high negative potential (- 2 7 V) will be required for a release of

hydrated electrons. However, there are some publications which mention the existence of

hydrated electrons of a more positive potential According to other reports, these hydrated electrons are trapped within a few microseconds

( c ) The shell of hydrated ions can be significantly changed, while flowing near the

electrode surface These changes are reversible and it is believed that the shell retains its

original shape as soon as the center ions leave the electron field In the last years, evidence has

been presented on the existence of the so called "memory of water". Extensive studies are

currently being carried out to find a reasonable explanation to many phenomena which otherwise can not be understood, unless some irreversible behavior of water molecule is assumed. The scale inhibition process exhibited by the device according to the present invention, can be explained by assuming that, for example the calcium and bicarbonate ions are

influenced by the strong electric field, causing some inhibition to the nucleation step, required

for the formation of the precipitated scale, such as calcium carbonate in this example.

The above explanation is supported by analytical measurements carried out by the inventors, which showed that there is not any difference in the concentration of all the ions

present in the solution before and after treatment of fluids using the devices described above which inhibits scale formation. It is also believed that the effect is controlled by the surface and

consequently an increase of the surface area will be required for a higher efficiency.

The term "fluid" to which the present invention refers includes generally any liquid such

as water, kerosene, oils, etc.

Although the invention has been described in terms of particular embodiments and

applications, one of ordinary skill in the art, in light of this teaching, can generate additional

embodiments and modifications without departing from the spirit of or exceeding the scope of

the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should

not be construed to limit the scope thereof.

Claims

WHAT IS CLAIMED IS:

1. A method for inhibiting scale formation on the walls of a conduit through which a fluid is passed, said fluid including dissolved constituents, comprising:

guiding the fluid through a chamber containing a plurality of small particles made of a

composition enabling electron transfer; and during the guiding of said fluid through said chamber, inducing generation of an electric

field in said fluid by virtue of said particles, said electric field being sufficient to cause

modification of nucleation patterns of said fluid, thereby causing an inhibition of essential

nucleation steps in said fluid which precede and govern scale formation.

2. The method defined in claim 1 wherein said particles are made of a metal alloy.

3. The method defined in claim 2, wherein said metal alloy comprises mainly copper.

4. The method defined in claim 3, wherein said particles are made of a metal alloy

containing more than 65% copper.

5. The method defined in claim 4, wherein said particles are made of a metal alloy

containing more than 75% copper.

6. The method defined in claim 2, wherein said particles are made of a metal alloy

containing a small amount of an element taken from the group consisting of nickel, zinc, and stanium.

7. The method defined in claim 2, wherein said particles are made of a metal alloy

containing minor constituents selected from the group consisting of iron, lead, aluminum,

manganese and noble metals

8. The method defined in claim 1 wherein said particles have a total surface area of at least 150 square centimeters.

9. A device for preventing mineral salt deposits in fluid use systems, comprising a capsule body having walls defining a chamber, said capsule body being insertable in a fluid

pipeline so that said chamber communicates on an upstream side and a downstream side with

said pipeline, a multiplicity of particles disposed in said chamber, said particles being made of a

composition enabling electron transfer.

10. The device defined in claim 9 wherein the composition of said particles is an alloy

with basic components taken from the group consisting of copper, tin, zinc, nickel, and iron.

1 1. The device defined in claim 10 wherein said alloy further includes auxiliary

components taken from the group consisting of silver, manganese, silicon, gold, and carbon.

12. The device defined in claim 1 1 wherein said alloy further includes attendant

components taken from the group consisting of phosphorus, sulfur, magnesium, aluminum,

vanadium, tungsten, molybdenum, and cobalt.

13 The device defined in claim 12 wherein at least 97% of said alloy by weight is

composed of said basic components

14 The device defined in claim 13 wherein at least 65% of said alloy by weight is

composed of copper and further includes selected ones of said basic components.

15 The device defined in claim 14 wherein said alloy contains said selected ones of said basic components each in an amount by weight of 5-7.5%

16 The device defined in claim 15 wherein said alloy includes selected ones of said

auxiliary components each in an amount by weight of 0 1-0 2%

17 The device defined in claim 16 wherein said alloy includes selected ones of said attendant components each in an amount by weight of 0 01-0 02%

18 The device defined in claim 15 wherein said alloy includes selected ones of said

auxiliary components and said attendant components in an aggregate amount by weight of less than approximately 2.5%

19 The device defined in claim 9 wherein the composition of said particles is an alloy containing at least 65% copper, said particles being spherical

20 The device defined in claim 19 wherein each of said particles is in contact with at least one other of said particles, at least some of said particles being in contact with said walls.

21. The device defined in claim 9 wherein said particles are spherical.

22. The device defined in claim 9 wherein each of said particles is in contact with at

least one other of said particles, at least some of said particles being in contact with said walls.

23. The device defined in claim 9 wherein said particles have a total surface area of at least 150 square centimeters.

24. The device defined in claim 9 wherein said chamber is an inner chamber disposed inside an outer chamber of said capsule body, said inner chamber communicating with said

pipeline on said upstream side, said outer chamber communicating with said pipeline on said downstream side, at least one of said walls being disposed between said inner chamber and said

outer chamber, said one of said walls being provided with a plurality of apertures through

which fluid flows from said inner chamber to said outer chamber, said one of said walls being

made, at least in regions including said apertures, of a composition enabling electron transfer.

25. The device defined in claim 24 wherein said apertures are star shaped.

26. The device defined in claim 24 wherein said aperatures have a diameter of at least

0.5 cm. 27 The device defined in claim 24 wherein one of said walls is made from a metal alloy

comprising more than 65% copper

28 A device for preventing mineral salt deposits in fluid use systems, comprising a

capsule body having walls defining a first chamber and a second chamber, said capsule body

being insertable in a fluid pipeline so that said first chamber communicates on an upstream side

with said pipeline and said second chamber communicates on a downstream side with said

pipeline, at least one of said walls being disposed between said first chamber and said second

chamber, said one of said walls being provided with a plurality of apertures through which fluid flows from said first chamber to said second chamber, said one of said walls being made, at

least in regions including said apertures, of a composition enabling electron transfer

29 The device defined in claim 28 wherein said first chamber is substantially surrounded by said second chamber

30 The device defined in claim 28 wherein said aperatures are substantially star-

shaped

31 The device defined in claim 28 wherein said apertures have a diameter of at least

0 5 centimeter

32 The device defined in claim 18 wherein said apertures are defined by surfaces having a total area of at least 150 square centimeters