U.S. patent application number 14/894721 was filed with the patent office on 2016-06-30 for determination device for determining antirust effect of treated water and method for determining the same.
The applicant listed for this patent is TOSHIKOGYO CO., LTD.. Invention is credited to Mitsuo Ishikawa, Nobuyuki Kamiya, Kunio Nemoto, Yasuo Tajiri.
Application Number | 20160187287 14/894721 |
Document ID | / |
Family ID | 54192811 |
Filed Date | 2016-06-30 |
United States Patent
Application |
20160187287 |
Kind Code |
A1 |
Tajiri; Yasuo ; et
al. |
June 30, 2016 |
Determination Device for Determining Antirust Effect of Treated
Water and Method for Determining the Same
Abstract
A determination device capable of easily and quickly determining
an enhancement in rust-prevention of treated water and a method for
determining the same are provided. The device has first and second
potential difference measurement devices, each including at least
one anode electrode, a pair of cathode electrodes, a first current
generator for applying an electric current between the anode and a
first cathode of the pair, a second current generator for applying
an electric current between the anode and a second cathode, an
electric current changer for periodically changing a magnitude of a
current between the first and second cathodes, a measurement/output
equipment for measuring a potential difference across the first and
second cathodes, and a determiner for determining antirust effect
of treated water based on signal A outputted by the equipment of
the first potential difference measurement device and signal B
outputted by that of the second device.
Inventors: |
Tajiri; Yasuo;
(Yokohama-shi, Kanagawa, JP) ; Ishikawa; Mitsuo;
(Yokohama-shi, Kanagawa, JP) ; Nemoto; Kunio;
(Yokohama-shi, Kanagawa, JP) ; Kamiya; Nobuyuki;
(Yokohama-shi, Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOSHIKOGYO CO., LTD. |
Yokohama-shi, Kanagawa |
|
JP |
|
|
Family ID: |
54192811 |
Appl. No.: |
14/894721 |
Filed: |
May 30, 2014 |
PCT Filed: |
May 30, 2014 |
PCT NO: |
PCT/JP2014/002890 |
371 Date: |
November 30, 2015 |
Current U.S.
Class: |
205/775.5 ;
204/404 |
Current CPC
Class: |
G01N 27/416 20130101;
G01N 27/4161 20130101; G01N 27/30 20130101; C02F 1/30 20130101;
G01N 33/18 20130101 |
International
Class: |
G01N 27/416 20060101
G01N027/416; G01N 27/30 20060101 G01N027/30 |
Claims
1. A determination device for determining antirust effect of
treated water comprising a first potential difference measurement
device and a second potential difference measurement device,
wherein the first potential difference measurement device includes:
at least one anode electrode, a pair of cathode electrodes having a
first cathode electrode and a second cathode electrode, a first
current generator for applying a first electric current between the
anode electrode and the first cathode electrode, a second current
generator for applying a second electric current between the anode
electrode and the second cathode electrode, an electric current
changer for periodically changing a magnitude of an electric
current between the first cathode electrode and the second cathode
electrode, and a measurement and output device for measuring a
first potential difference across the first cathode electrode and
the second cathode electrode, wherein the second potential
difference measurement device includes: at least one comparative
anode electrode, a pair of comparative cathode electrodes having a
first comparative cathode electrode and a second comparative
cathode electrode, a first current generator for comparison, for
applying a first electric current for comparison between the
comparative anode electrode and the first comparative cathode
electrode, a second current generator for comparison, for applying
a second electric current for comparison between the comparative
anode electrode and the second comparative cathode electrode, an
electric current changer for comparison, for periodically changing
a magnitude of a comparative electric current between the first
comparative cathode electrode and the second comparative cathode
electrode, and a measurement and output device for comparison, for
measuring a second potential difference across the first
comparative cathode electrode and the second comparative cathode
electrode, wherein the at least one anode electrode and the pair of
cathode electrodes of the first potential difference measurement
device are immersed in treated water that has been treated with a
water treatment device, and the at least one comparative anode
electrode and the pair of comparative cathode electrodes of the
second potential difference measurement device are immersed in
untreated water that has not been treated with a water treatment
device, and a determiner for determining antirust effect of the
treated water based on an output signal A outputted by the
measurement, and output device of the first potential difference
measurement device and an output signal B outputted by the
measurement and output device for comparison of the second
potential difference measurement device.
2. The determination device according to claim 1, the first
potential difference measurement device further including a third
current generator for applying an electric current between the
first cathode electrode and the second cathode electrode, and the
second potential difference measurement device further including a
third current generator for comparison, for applying a comparative
electric current between the first comparative cathode electrode
and the second comparative cathode electrode.
3. The determination device according to claim 1, wherein the
determiner determines the antirust effect of the treated water
based on a ratio of a level of the output signal A to a level of
the output signal B.
4. The determination device according to claim 1, wherein the pair
of the cathode electrodes and the pair of the comparative cathode
electrodes have a surface made of silver, and the anode electrode
and the comparative anode have a surface made of platinum.
5. The determination device according to claim 1, wherein the water
treatment device contacts water with a hybrid ceramic which emits
far-infrared rays having wavelengths from 4.4 .mu.m to 15.4 .mu.m
at an integral emissivity of 92% or more.
6. A method for determining antirust effect of treated water
comprising: applying an electric current between a first cathode
electrode of a pair of cathode electrodes and at least one anode
electrode, and between a second cathode electrode of the pair of
cathode electrodes and the anode electrode, wherein the first
cathode electrode, the second cathode electrode, and the anode
electrode are immersed in treated water that has been treated with
a water treatment device; applying a comparative electric current
between a first comparative cathode electrode of a pair of
comparative cathode electrodes and at least one comparative anode
electrode, and between a second comparative cathode electrode of
the pair of comparative cathode electrodes and the comparative
anode electrode, wherein the first comparative cathode electrode,
the second comparative cathode electrode, and the comparative anode
electrode are immersed in untreated water that has not been treated
with a water treatment device; and determining antirust effect of
the treated water based on a first potential difference across the
first cathode electrode and the second cathode electrode, and a
second potential difference across the first comparative cathode
electrode and the second comparative cathode electrode.
7. The method according to claim 6, wherein the antirust effect of
the treated water is determined based on a ratio of the first
potential difference to the second potential difference.
8. The method according to claim 6, wherein the pair of cathode
electrodes and the pair of comparative cathode electrodes have a
surface made of silver, and the anode electrode and the comparative
anode electrode have a surface made of platinum.
9. The method according to claim 6, wherein the water treatment
device contacts water with a hybrid ceramic which emits
far-infrared rays having wavelengths from 4.4 .mu.m to 15.4 .mu.m
at an integral emissivity of 92% or more.
10. The determination device according to claim 2, wherein the
determiner determines the antirust effect of the treated water
based on a ratio of a level of the output signal A to a level of
the output signal B.
11. The determination device according to claim 2, wherein the pair
of the cathode electrodes and the pair of the comparative cathode
electrodes have a surface made of silver, and the anode electrode
and the comparative anode have a surface made of platinum.
12. The determination device according to claim 3, wherein the pair
of the cathode electrodes and the pair of the comparative cathode
electrodes have a surface made of silver, and the anode electrode
and the comparative anode have a surface made of platinum.
13. The method according to claim 7, wherein the pair of cathode
electrodes and the pair of comparative cathode electrodes have a
surface made of silver, and the anode electrode and the comparative
anode electrode have a surface made of platinum.
Description
TECHNICAL FIELD
[0001] The present invention relates to a determination device for
determining antirust effect of treated water and a method for
determining antirust effect of treated water. More particularly,
the present invention relates to a determination device capable of
determining, easily and in a short time, an enhancement in
rust-prevention of treated water as a result of the treatment, and
to a method for determining antirust effect of treated water.
BACKGROUND ART
[0002] In general, when a metal piece is immersed in water for a
long time, the surface of the metal piece becomes corroded. Metal
corrosion is caused by localized polarization of a part of the
surface into an anode and a cathode. A small amount of electric
current flows between the anode and the cathode, which causes an
oxidation reaction at the anode and a reduction reaction at the
cathode. The oxidation reaction at the anode oxidizes the surface
of the metal piece, whereby the metal corrosion progresses.
[0003] Various kinds of water treatment devices capable of
purifying water with ceramics that emits far-infrared rays have
been conventionally known as water treatment devices. An example of
the water treatment devices may be a device named "THE BIOWATER"
(registered trademark), which is sold on market by TOSHIKOGYO CO.,
LTD. (see Non-patent document 1). It is reported that water treated
with this device has various advantages. Especially noticeable is
its effectiveness in preventing deterioration caused by red rust.
More particularly, metal corrosion progresses more slowly in water
treated with this water treatment device than in untreated water.
In other words, the treatment of water with the water treatment
device enhances antirust effect of water. When the water treatment
device is installed, for example, in the piping, through which the
water treated with the water treatment device is made to pass, the
progress of metal corrosion on the inner surface of the piping is
capable of being controlled.
[0004] It normally takes a time period from a few months to several
years to assess the progress of metal corrosion by observing and
analyzing the surface of metal pieces immersed in water.
Conventionally, it also takes a time period from a few months to
several years from the installation of a water treatment device in
a piping to determine the effectiveness of the device in
controlling metal corrosion on the inner surface of the piping.
Thus, currently it is not possible to determine an improvement in
the rust-prevention of treated water within a short time period
from the installation.
[0005] Also, in general, a water treatment device is usually placed
in a piping of large facilities such as factories and buildings.
When the piping in which a water treatment device is installed is
examined and the effectiveness in treating water with the water
treatment device is determined, it is necessary to temporarily stop
operation of the equipment provided with the device, to drain water
from the piping, and then to observe the inner surface of the
piping. However, it is often practically difficult to stop
operation of the equipment and it requires prodigious labor to
drain water from the piping. Thus it is difficult to check whether
the anti-corrosion performance of water is enhanced owing to the
installment of a water treatment device by examining the piping in
which the water treatment device is installed.
PRIOR ART DOCUMENTS
Patent Documents
[0006] Non-patent Document 1: "Introduction of the Products" in the
website of TOSHIKOGYO CO, LTD. whose URL is
http://www.biowater.co.jp/product/feature.html (searched on Apr.
21, 2014).
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0007] The objective of the present invention is to provide a
determination device for determining antirust effect of treated
water, capable of determining, easily and in a short time, an
enhancement in anti-corrosion performance of water treated with a
water treatment device, and a method for determining antirust
effect of the treated water.
Means to Solve the Problems
[0008] Means to achieve the objective are as follows:
(1) A determination device for determining antirust effect of
treated water comprising a first potential difference measurement
device and a second potential difference measurement device, each
of which includes:
[0009] at least one anode electrode,
[0010] a pair of cathode electrodes,
[0011] a first current generator for applying an electric current
between the anode electrode and a first cathode electrode of the
pair of cathode electrodes,
[0012] a second current generator for applying an electric current
between the anode electrode and a second cathode electrode of the
pair of cathode electrodes,
[0013] an electric current changer for periodically changing a
magnitude of an electric current between the first cathode
electrode and the second cathode electrode,
[0014] a measurement and output device for measuring a potential
difference across the first cathode electrode and the second
cathode electrode, [0015] wherein the at least one anode electrode
and the pair of cathode electrodes of the first potential
difference measurement device are immersed in treated water that
has been treated with a water treatment device, and the at least
one anode electrode and the pair of cathode electrodes of the
second potential difference measurement device are immersed in
untreated water that has not been treated with a water treatment
device, and
[0016] a determiner for determining antirust effect of the treated
water based on an output signal A outputted by the measurement and
output device of the first potential difference measurement device
and an output signal B outputted by the measurement and output
device of the second potential difference measurement device.
(2) The determination device according to item (1), each of the
first and second potential difference measurement devices further
including a third current generator for applying an electric
current between the first cathode electrode and the second cathode
electrode. (3) The determination device according to item (1) or
(2), wherein the determiner determines the antirust effect of the
treated water based on a ratio of a level of the output signal A to
a level of the output signal B. (4) The determination device
according to any one of items (1)-(3), wherein the pair of the
cathode electrodes has a surface made of silver and the anode
electrode has a surface made of platinum. (5) The determination
device according to any one of items (1)-(4), wherein the water
treatment device contacts water with a hybrid ceramic which emits
far-infrared rays having wavelengths from 4.4 .mu.m to 15.4 .mu.m
at an integral emissivity of 92% or more. (6) A method for
determining antirust effect of treated water comprising:
[0017] applying an electric current between a cathode electrode and
a first anode electrode, and between the cathode electrode and a
second anode electrode, wherein the cathode electrode, the first
anode electrode, and the second anode electrode are immersed in
treated water that has been treated with a water treatment
device;
[0018] applying an electric current between a comparative cathode
electrode and a first comparative anode electrode, and between the
comparative cathode electrode and a second comparative anode
electrode, wherein the comparative cathode electrode, the first
comparative anode electrode, and the second comparative anode
electrode are immersed in untreated water that has not been treated
with a water treatment device; and
[0019] determining antirust effect of the treated water based on a
first potential difference across the first cathode electrode and
the second cathode electrode, and a second potential difference
across the first comparative cathode electrode and the second
comparative cathode electrode.
(7) The method according to item (6), wherein the antirust effect
of the treated water is determined based on a ratio of the first
potential difference to the second potential difference. (8) The
method according to item (6) or (7), wherein the pair of cathode
electrodes and the pair of comparative cathode electrodes have a
surface made of silver, and the anode electrode and the comparative
anode electrode have a surface made of platinum. (9) The method
according to any one of items (6)-(8), wherein the water treatment
device contacts water with a hybrid ceramic which emits
far-infrared rays having wavelengths from 4.4 .mu.m to 15.4 .mu.m
at an integral emissivity of 92% or more.
Advantages of the Invention
[0020] According to the present invention, the cathode reaction is
capable of being expedited by the application of an electric
current between the anode electrode and the cathode electrodes.
Thus the formation of a calcium carbonate film on the cathode
electrodes progresses so quickly that a difference between the
rust-prevention of the treated water and that of the untreated
water can be determined even if a short time is expended on the
experiment. Thanks to this invention, researchers no longer have to
conduct experiments that involve immersing metal pieces in water
for a long time, from months to years. The present invention
provides a determination device for determining antirust effect of
treated water and a method for determining antirust effect of
treated water, capable of determining an improvement in
rust-prevention of water by a short-term experiment that requires
only several days.
[0021] Also, the determination device for determining antirust
effect of treated water and the method for determining antirust
effect of treated water according to the present invention are
capable of determining antirust effect of treated water by
utilizing a potential difference across the two electrodes of a
pair of cathode electrodes. This is a simple method that does not
include actual observation of the surface of a metal piece immersed
in the water.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a schematic illustration showing the structure of
a first potential difference measurement device.
[0023] FIG. 2 is a schematic illustration showing the structure of
a determination device for determining antirust effect of treated
water according to the present invention.
[0024] FIG. 3 is a schematic circuit diagram of a control unit for
the first and second current generators.
[0025] FIG. 4 is a schematic illustration showing an example of how
the water treatment device is installed in a piping.
[0026] FIG. 5 is a graph showing how voltages measured in the
working example changed with time.
EMBODIMENTS TO CARRY OUT THE INVENTION
[0027] The determination device for determining antirust effect of
treated water according to the present invention has a first
potential difference measurement device, a second potential
difference measurement device, and a determiner. We will explain
the first potential difference measurement device in the following,
referring to FIG. 1. It should be noted that the second potential
difference measurement device has the same structure as the first
potential difference measurement device shown in FIG. 1.
[0028] As shown in FIG. 1, the first potential difference
measurement device 11 includes at least one anode electrode 2, a
pair of cathode electrodes 3, a first current generator 14 for
applying an electric current between the at least one anode
electrode 2 and a first cathode electrode 13 of the pair of cathode
electrodes, and a second current generator 24 for applying an
electric current between the at least one anode electrode 2 and a
second cathode electrode 23 of the pair of cathode electrodes. The
at least anode electrode 2 of the example shown in FIG. 1 is
comprised of two anode electrodes. A first anode electrode 12 of
the two anode electrodes is connected with the first cathode
electrode 13 and a second anode electrode 22 thereof with the
second cathode electrode 23.
[0029] When the first current generator 14 and the second current
generator 24 are activated after the at least one anode electrode 2
and the pair of cathode electrodes 3 are immersed in water, a first
electric current flows between the first anode electrode 12 and the
first cathode electrode 13, and a second electric current flows
between the second anode electrode 22 and the second cathode
electrode 23. These first and second electric currents respectively
cause an anode reaction at the anode electrodes 2 and a cathode
reaction at the cathode electrodes 3.
[0030] There is no special limitation on the shape of the anode
electrodes; they may be in the shape of a plate, a rod, or a
wire.
[0031] The anode reaction is generally an oxidation reaction. When
the surface of the anode electrode 2 is made of a metal with a
small ionization tendency, such as Pt, the reaction represented by
formula (1) is mainly caused at the anode electrode. On the other
hand, when the surface of the anode electrode 2 is made of a metal
with a relatively large ionization tendency, such as Cu, the
reaction represented by formula (2) is mainly caused.
2H.sub.2O.fwdarw.O.sub.2+4H.sup.++4e.sup.- (1)
Cu.fwdarw.Cu.sup.2++2e.sup.- (2)
[0032] The reaction represented by formula (2) dissolves the metal
of which the anode electrode 2 is made. When the metal is dissolved
into water, impurities in the water increase. The increased
impurities hamper the anode reaction and the cathode reaction,
which may, in turn, interfere with accurate determination of the
antirust effect of treated water. Thus, the surface of the anode
electrode 2 should preferably be made of a metal with a small
ionization tendency so that the metal of the anode electrode 2 will
not be dissolved into water by electrolysis. Specifically,
electrodes known as insoluble electrodes may be used as the anode
electrode 2. More specifically, electrodes whose surface is covered
with films of platinum or iridium oxide may be used as the anode
electrode 2. Electrodes covered with films of platinum or iridium
oxide may be produced by plating the surface of a base for
electrodes made of other metals such as titanium with platinum or
by baking iridium oxide on the surface.
[0033] The cathode reaction is generally a reduction reaction. For
example, a reaction represented by formula (3) or (4) may be
caused.
O.sub.2+2H.sub.2O+4e.sup.-.fwdarw.4OH.sup.- (3)
2H.sub.2O+2e.sup.-2OH.sup.-+H.sub.2 (4)
[0034] The hydroxide ions OH.sup.- produced in the reaction
represented by formula (3) or (4) raise the pH of the water
surrounding the cathode electrodes 3. When the pH becomes high,
CO.sub.3.sup.2- ions are prone to be released from carbon dioxide
gas that is dissolved in the water. Then calcium ions Ca.sup.2+ and
CO.sub.3.sup.2- are prone to react with each other in the water,
which produces CaCO.sub.3. As a result, as the cathode reaction
progresses, a film of CaCO.sub.3, which may be called "calcium
carbonate" hereinafter", is formed on the surface of the cathode
electrodes 3.
[0035] The calcium carbonate can have a crystal structure of
aragonite or of calcite. The aragonitic crystals are known to be in
the form of needles, while the calcitic crystals are known to be in
the form of granules. Calcium carbonate with a higher proportion of
aragonitic crystals adheres to the cathode electrodes in such a
manner that needle-like crystals adhere to the electrodes with many
gaps between the needles. As a result, the surface of the
electrodes is sparsely covered with films of calcium carbonate. On
the other hand, calcium carbonate with a higher proportion of
calcitic crystals adheres to the cathode electrodes in such a
manner that granular crystals closely adhere to the electrodes,
with no space left. Thus the surface of the electrodes is uniformly
covered with a film of calcium carbonate without gaps. The larger
the area of the surface of the cathode electrodes 3 covered with
films of calcium carbonate is, the more increased the electrical
resistance of the cathode electrodes 3 is. Therefore films of
calcium carbonate with a higher proportion of calcitic crystals
closely adhere to the surface of the cathode electrodes 3, without
gaps between the films, compared with films of calcium carbonate
with a higher proportion of aragonitic crystals, even if the mass
of the former is the same as that of the latter. Thus, the former
increases the electrical resistance of the surface of the
electrodes more than the latter.
[0036] When a metal piece is immersed in water, films of calcium
carbonate are formed on the surface of the metal piece by the
cathode reaction. The calcium carbonate films serve as a protective
film for the surface of the metal piece, which controls oxidation
of the surface. Also, when the surface of the metal piece is
covered with films of calcium carbonate, it is hard for an electric
current to flow between an anode and a cathode caused by localized
polarization of the surface. As a result, oxidation of the metal
surface caused by the anode reaction is controlled. Therefore as
films of calcium carbonate adhere to the metal surface more closely
without gaps, it is more capable of controlling corrosion of
metals.
[0037] The surface of the cathode electrodes 3 may be made of
materials that are publicly known and used as materials for the
negative electrode of electrolytic apparatuses. Specifically, the
surface of the cathode electrodes 3 may be made of a metal or alloy
with a small ionization tendency, or a metal or alloy excellent in
corrosion resistance. More specifically, the surface of the cathode
electrodes 3 may be made of silver or copper. Cathode electrodes 3
whose surface is covered with silver or copper may be produced by
preparing cathode electrodes that are made of silver or copper in
their entirety or by plating the outer surface of a base for
electrodes made of other metals with silver or copper.
[0038] The first current generator 14 applies a first electric
current between the first anode electrode 12 and the first cathode
electrode 13. The second current generator 24 applies a second
electric current between the second anode electrode 22 and the
second cathode electrode 23. Each of the first current generator 14
and the second current generator 24 may be a device for providing
an electric current of a constant magnitude. Alternatively, it may
be a device that is controlled to periodically change the magnitude
of an electric current to be provided. The product of the
multiplication of the magnitude of the electric current applied by
the first current generator 14 by the time period of the
application of the electric current, which product may be called a
"quantity of electricity" hereinafter, should preferably be almost
the same as the quantity of electricity applied by the second
current generator 24. For example, when the first current generator
14 and the second current generator 24 are operated for one hour,
the value of the current applied by the first current generator 14
may be set to 4.5 .mu.A and the value of the current applied by the
second current generator 24 may be set to 3.5 .mu.A for the first
half of the time period, while the current value of the first
current generator may be 3.5 .mu.A and the current value of the
second current generator may be 4.5 .mu.A for the latter half of
the period. Thus the quantity of electricity generated by the first
current generator 14 may be adjusted to the same as that generated
by the second current generator 24 after one hour's operation of
the generators.
[0039] There is no special limitation on the first current
generator 14 and the second current generator 24, as long as the
generators are capable of generating electric currents. Commercial
power supplies may be used for this purpose. Also, a single power
supply may be used for both of the first current generator 14 and
the second current generator 24.
[0040] As shown in FIG. 3, for example, the device may be provided
with a single power supply 92 for both of the first current
generator 14 and the second current generator 24, and further
provided with two current transducers 93 and 94 downstream of the
power supply 92. The power circuit should be so designed that the
first current transducer 93 and the second current transducer 94
send electric currents respectively to the first current generator
14 and the second current generator 24. Specifically, the power
circuit should be provided with a control circuit 95 which controls
the current transducers in such a manner that the first current
transducer 93 sends electric currents to one of the first current
generator 14 and second current generator 24, and the second
current transducer 94 sends electric currents to the other of the
first current generator 14 and second current generator 24. The
power circuit should further be provided with a flip-flop
controller 96 capable of switching a flow path of the output
electric current at regular intervals between a path from the first
current transducer 93 to one of the first current generator 14 and
second current generator 24 and a path from the second current
transducer 94 to the other of the first current generator 14 and
second current generator 24. Although there is no limitation on the
frequency at which the flow path is switched by the flip-flop
controller 96, the flow path should be switched at a frequency from
approximately once every five minutes to approximately once an
hour.
[0041] The larger the magnitude of the electric current applied by
the first current generator 14 and the second current generator 24
is, the more rapidly the cathode reaction is caused. This rapid
cathode reaction means that the time period necessary for the
determination is decreased. On the other hand, if the electric
current applied by the first current generator 14 and the second
current generator 24 is too large, there is a danger that the user
receives an electric shock when s/he touches the electrodes. Also,
hydrogen gas vigorously produced at the cathode electrodes may
deprive the cathode electrodes of the calcium carbonate films.
Therefore the current density applied by the first current
generator 14 and the second current generator 24 should be
approximately from 10 .mu.A/cm.sup.2 to 200 .mu.A/cm.sup.2.
[0042] The at least one anode electrode 2 may be comprised of one
anode electrode or several anode electrodes. The number of the at
least one anode electrode 2 should preferably be the same as that
of cathode electrodes 3.
[0043] The first potential difference measurement device 11 has an
electric current changer 35 and a measurement and output device 36,
as shown in FIG. 1. The device may further include a third current
generator 34.
[0044] The third current generator 34 applies an electric current
between the first cathode electrode 13 and the second cathode
electrode 23. The electric current changer 35 changes the magnitude
of the electric current flowing through the pair of cathode
electrodes at regular intervals. Although there is no limitation on
the frequency at which the magnitude of the electric current is
changed by the electric current changer 35, the magnitude should be
changed at a frequency approximately from once every five minutes
to once an hour.
[0045] Any generator may be employed as the third current generator
34, as long as it is capable of applying a constant magnitude of an
electric current. Commercial constant current sources may be used
as the third current generator 34.
[0046] This third current generator 34 may be operated while the
first current generator 14 and the second current generator 24 are
being operated. When the third current generator 34 and the first
and second current generators 14, 24 are operated simultaneously,
the magnitude of the electric current applied by the first current
generator 14 should be the same as that of the electric current
applied by the second current generator 24. Also, the magnitude of
the electric current applied by the third current generator 34
should preferably be smaller than that of the electric current
applied by the first current generator 14 and that of the electric
current applied by the second current generator 24. When the
electric currents applied by the first, second and third current
generators satisfy this relationship, the cathode reaction always
occurs at the first cathode electrode 13 or the second cathode
electrode 23. When the third current generator 34 is operated while
the first current generator 14 and the second current generator 24
are kept operating in such a manner that they generate a same
magnitude of an electric current, the magnitude of the electric
current flowing through the first cathode electrode 13 and that of
the electric current flowing through the second cathode electrode
23 may be controlled by controlling the direction and magnitude of
an electric current applied between the pair of cathode electrodes
by the third current generator 34. Therefore the employment of the
third current generator 34 enables the user to control the electric
current flowing through the pair of cathode electrodes only by
controlling the electric current applied by the third current
generator 34 without controlling the electric current applied by
the first current generator 14 and that applied by the second
current generator 24.
[0047] Alternatively, only the third current generator 34 may be
activated after the first current generator 14 and the second
current generator 24 are stopped.
[0048] The measurement and output device 26 measures a potential
difference across the first cathode electrode 13 and the second
cathode electrode 23, and outputs and sends the measured potential
difference to a determiner 91. When the potential difference is
measured, either the first cathode electrode 13 or the second
cathode electrode 23 is used as reference electrode and the other
is used as working electrode.
[0049] Application of a voltage is necessary to enable the third
current generator 34 to pass an electric current through the first
cathode electrode 13 and the second cathode electrode 23. A voltage
necessary to drive an electric current of a constant magnitude is
in proportion to the electrical resistance of the cathode
electrodes 3. As explained hereinbefore, the more calcium carbonate
films are formed on the surface of the cathode electrodes and the
higher the proportion of calcitic crystals in the calcium carbonate
films is, the larger the electrical resistance of the cathode
electrodes 3 is.
[0050] As another method of measuring the electrical resistance of
the cathode electrodes 3, a constant-voltage supply for applying a
constant voltage may be used as the third current generator 34 and
then the magnitude of an electric current flowing through the first
cathode electrode 13 and the second cathode electrode 23 may be
measured with the measurement and output device 36. Thus this
method also works for this invention.
[0051] As shown in FIG. 2, the first potential difference
measurement device 11 is used for treated water 41 that has been
treated with a water treatment device, while a second potential
difference measurement device 61 is used for untreated water 42.
More specifically, when the determination device for determining
antirust effect of treated water according to the present invention
is used, the at least one anode electrode 2 and the cathode
electrodes 3 of the first potential difference measurement device
11 are immersed in the treated water 41, while at least one
comparative anode electrode 52 and comparative cathode electrodes
53 are immersed in the untreated water 42.
[0052] The water treatment device may include those having a hybrid
ceramic placed in a piping, such as "THE BIOWATER" (registered
trademark), which is manufactured by TOSHIKOGYO CO., LTD. The
hybrid ceramic is one which emits far-infrared rays having
wavelengths from 4.4 .mu.m to 15.4 .mu.m at an integral emissivity
of 92% or more. Water treated with this device is improved in at
least one of a capability to activate life, bacteriostatic
capability, antioxidative capability, detergent ability,
environmental cleanup capability, treated condition-sustaining
capability, and anticorrosion property (see Non-patent document
1).
[0053] Treated water 41 that has been treated with a water
treatment device has enhanced rust-prevention, compared with
untreated water 42. In other words, a metal piece immersed in
treated water 41 has a smaller rate of corrosion than a metal piece
immersed in untreated water 42.
[0054] Specifically, the cathode reaction tends to form calcium
carbonate crystals abundant in calcitic crystals on the surface of
a metal piece that is immersed in treated water 41. As a result,
the surface of the metal piece is covered with films of calcium
carbonate all over. The films control progress of the corrosion. On
the other hand, the cathode reaction tends to form calcium
carbonate crystals including a high proportion of aragonitic
crystals on the surface of a metal piece that is immersed in
untreated water 42. As a result, the surface of the metal piece is
sparsely covered with films of calcium carbonate. The metal piece
begins to corrode at the portions that are not covered with the
calcium carbonate films and the corrosion is likely to further
proceed.
[0055] In FIG. 2, films of calcium carbonate with a high proportion
of calcitic crystals are likely to be formed on the cathode
electrodes 3 immersed in treated water 41, compared with those
formed on the comparative cathode electrodes 53 immersed in
untreated water 42. Thus the electrical resistance of the cathode
electrodes 3 becomes larger than that of the comparative cathode
electrodes 53. Consequently, as the cathode reaction progresses,
the voltage necessary to make a constant magnitude of an electric
current pass through the first cathode electrode 13 and the second
cathode electrode 23 becomes larger than the voltage necessary to
make the same magnitude of an electric current pass through the
first comparative cathode electrode 63 and the second comparative
cathode electrode 73.
[0056] The determiner 91 is capable of determining antirust effect
of treated water 41 based on an output signal A and an output
signal B. There is no special limitation on the kinds of the output
signals A and B, as long as the signals serve the functions
required by the present invention. For example, the potential
difference across the first cathode electrode 13 and the second
cathode electrode 23, the value of the electric current passing
through the first cathode electrode 13 and the second cathode
electrode 23, or the electrical resistance of the cathode
electrodes 3 may be used as the output signal A. The output signal
B should be a signal of the same kind as the output signal A. For
example, when the output signal A is the potential difference
across the first cathode electrode 13 and the second cathode
electrode 23, the output signal B should be the potential
difference across the first comparative cathode electrode 63 and
the second comparative cathode electrode 73.
[0057] The determiner 91 is capable of determining antirust effect
of treated water 41 based on the output signal A and the output
signal B. Specifically, the determiner 91 calculates the ratio of
the output signal A to the output signal B, the ratio of the output
signal B to the output signal A, or the difference between the
output signal A and the output signal B, based on which the
antirust effect is determined. Let the case where the output
signals A and B are potential differences across the respective
pairs of cathode electrodes be taken as an example. When the output
signal A is larger than the output signal B, the cathode electrodes
3 immersed in treated water 41 is considered to have a surface a
larger area of which is covered with films of calcium carbonate
including a high proportion of calcitic crystals than the
comparative cathode electrodes 53 immersed in untreated water 42
have. Thus when the determiner 91 finds that the output signal A is
larger than the output signal B, the determiner determines that the
examined water has been treated to a water in which metal pieces
are not easily corroded, or the rust-prevention of the treated
water is enhanced.
[0058] A conventionally known device may be used as the electric
current changer 35. The measurement and output device 36 may be a
combination of a device for measuring electrical values such as the
potential difference across one cathode electrode and the other
cathode electrode of a pair of cathode electrodes, and an output
device for outputting and sending measured results to the
determiner 91.
[0059] The operation of the device will be explained
hereinafter.
[0060] Facilities suppliers would sometimes like to check whether
water in a piping is treated and whether metal on the inner surface
of the piping is kept from corroding by installing a water
treatment device 102, such as "THE BIOWATER (registered
trademark)", in the piping in such a manner as shown, for example,
in FIG. 4. On such occasions, facilities suppliers may use the
determination device for determining antirust effect of treated
water according to the present invention. The operation method of
this device will be explained in the following: First, untreated
water 41 in the piping is sampled through a three-way valve 104
that is fixed to the piping at a place upstream of the water
treatment device 102. Treated water 42 is also sampled through a
three-way valve 105 that is fixed to the piping at a place
downstream of the water treatment device 102. The samples are
collected in vessels such as beakers. As shown in FIG. 2, the
cathode electrodes 3 and anode electrodes 2 of the first potential
difference measurement device 11 are immersed in the treated water
41 in one vessel, and the comparative cathode electrodes 53 and
comparative anode electrodes 52 of the second potential difference
measurement device 61 are immersed in the untreated water 42 in
another vessel.
[0061] Then, the first current generators 14 and 64, and the second
current generators 24 and 74 are activated to make electric
currents pass through the first cathode electrode 13 and the second
cathode electrode 23 and through the first comparative cathode
electrode 63 and the second comparative cathode electrode 73
respectively. The electric currents cause the cathode reaction
respectively at the cathode electrodes 13, 23 and at the
comparative cathode electrodes 63, 73, on the surface of which
films of calcium carbonate are formed. For example, when electric
currents are applied by the first current generator 14 and the
first current generator for comparison 64 at a current density from
about 10 .mu.A/cm.sup.2 to 200 .mu.A/cm.sup.2 for about 5 to 500
hours, films of calcium carbonate are formed on the surface of the
cathode electrodes 13, 23, 63, and 73 to such a degree that the
antirust effect of the treated water 41 is determined. Also, when
the hardness of the treated water 41 and that of the untreated
water 42 are increased, it serves to reduce the time period for
which electric currents are applied. If an increase in the hardness
of the treated and untreated waters is desired, the addition of a
salt, such as calcium carbonate, would suffice for the purpose. For
an accurate determination of the antirust effect, the salt to be
added to the treated water 41 should be the same as that to be
added to the untreated water 42 in the kind and quantity.
[0062] The treated water 41 has enhanced rust-preventive property
compared with the untreated water 42. Calcium carbonate crystals
abundant in calcitic crystals are more easily precipitated out at
the cathode electrodes 3 immersed in the treated water 41 than at
the comparative cathode electrodes 53 immersed in the untreated
water 42. Thus the surface of the cathode electrodes 3 is covered
with films of calcium carbonate all over, compared with the surface
of the comparative cathode electrodes 53.
[0063] The third current generators 34 and 84 are further
activated, while the first current generators 14, 64 and the second
current generators 24, 74 are being kept driving. The third current
generator 34 makes a constant magnitude of an electric current pass
through the first cathode electrode 13 and the second cathode
electrode 23, and the third current generator for comparison 84
makes a constant magnitude of an electric current pass through the
first comparative cathode electrode 63 and the second comparative
cathode electrode 83, wherein the electric currents are adjusted so
that the former constant magnitude is the same as the latter
constant magnitude. Furthermore, the magnitude of the electric
current applied by the first current generator 14 should be the
same as that of the electric current applied by the first current
generator for comparison 64, and the magnitude of the electric
current applied by the second current generator 24 should be the
same as that of the electric current applied by the second current
generator for comparison 74. Moreover, the magnitude of the
electric current applied by the third current generator 34 should
be smaller than that of the electric current applied by each of the
first current generators 14, 64 and by each of the second current
generators 24, 74.
[0064] When the current density of the electric current applied by
the third current generator is from about 0.5 .mu.A/cm.sup.2 to
about 25 .mu.A/cm.sup.2, the antirust effect of the treated water
41 is capable of being determined promptly and accurately.
[0065] Then, the measurement and output devices 36 and 86
respectively measure the potential difference across the first
cathode electrode 13 and the second cathode electrode 23 and the
potential difference across the first comparative cathode electrode
63 and the second comparative cathode electrode 73. The larger the
potential difference across the cathode electrodes, the larger the
electrical resistance at the cathode electrodes, which means that
films of calcium carbonate abundant in calcitic crystals are formed
at the cathode electrodes.
[0066] The measurement and output devices 36 and 86 output and send
the measured potential differences, respectively as an output
signal A and an output signal B, to the determiner 91. The
determiner 91 checks whether the ratio of the output signal A to
the output signal B is more than 100%. When it is the case, the
determiner 91 determines that the cathode electrodes 3 have a
larger electrical resistance than the comparative cathode
electrodes 53 and that the antirust effect of treated water 41 is
enhanced.
[0067] The determination device 1 for determining antirust effect
of treated water according to the present invention is capable of
checking an improvement in the antirust effect of water by
measuring electrical properties such as potential differences
across the cathode electrodes 3 and across the comparative cathode
electrodes 5. Thus it is not necessary to observe the inner surface
of the piping 103 to check whether corrosion of metal on the inner
surface of the piping 103 is controlled by the installation of a
water treatment device 102. Therefore the user does not bother to
stop the operation of the equipment or to drain water from the
piping 103; this device enables the user to check whether a water
treatment device 102 serves to improve the antirust effect easily
and conveniently.
[0068] Furthermore, the determination device 1 for determining
antirust effect of treated water according to the present invention
is capable of expediting the cathode reaction that occurs in metal
pieces immersed in water by the application of an electric current.
Thus it does not take a long time period from a few months to
several years from the installation of a water treatment device 102
in a piping to observe the progress of corrosion in order to
determine the effectiveness of the device in controlling metal
corrosion, but just a short period of several days to check an
enhancement in the antirust effect of water.
[0069] In addition, the antirust effect of treated water may be
determined by measuring the potential difference across the first
cathode electrode and the second cathode electrode without using
the third current generator 34. For example, the potential
difference across the first cathode electrode 13 and the second
cathode electrode 23 may be measured under the conditions where the
magnitude of an electric current applied by the first current
generator 14 is set to a value that is different from the magnitude
of an electric current applied by the second current generator 24.
Also, the magnitude of electric currents flowing through the
cathode electrodes 3 may be controlled by changing the magnitude of
an electric current applied by the first current generator 14 and
the magnitude of an electric current applied by the second
generator at regular intervals by means of the electric current
changer 35. Furthermore, when the potential differences are used as
output signals, the operation of the first current generators 14,
24, 64 and 74 should be controlled so that the magnitude of the
electric current flowing through the first cathode electrode 13 and
the second cathode electrode 23 is the same as that of the electric
current flowing through the first comparative cathode electrode 63
and the second comparative cathode electrode 73.
[0070] We will further explain the invention by means of
examples.
Working Example 1
[0071] Calcium sulfate was added to 5,000 mL of tap water so that
the hardness of the water would be 300 ppm. Untreated water 42 was
thus produced. Two pieces of hybrid ceramic, each of which was 13.5
mm in diameter and 19 mm in length, were placed in the untreated
water 42. The hybrid ceramic pieces were the same as those
incorporated into a device named "THE BIOWATER". The water with the
two pieces of hybrid ceramic was allowed to stand for 15 minutes.
Treated water 41 was thus produced. In this treated water 41 were
immersed two anode electrodes 2 and two cathode electrodes 3 of a
first potential difference measurement device 11 of a determination
device for determining antirust effect of treated water 1. Also, in
untreated water 42 were immersed two comparative anode electrodes
52 and two comparative cathode electrodes 53 of a second potential
difference measurement device 61 of a determination device for
determining antirust effect of treated water 1. An electrode with a
surface of polished silver was used as each of the cathode
electrodes 3 and 53, while a platinum-plated electrode was used as
each of the anode electrodes 2 and 52. Each of the cathode
electrodes 13, 23, 63, and 73 had a surface area of 0.2
cm.sup.2.
[0072] Then, the first current generators 14 and 64 and the second
current generators 24 and 74 were driven for 48 hours so that they
would provide an electric current of 4 .mu.A. The magnitude of the
electric current applied by the first current generators 14 and 64
was 4 .mu.A. After the 48 hours, the third current generator 34 and
84 were activated while the first current generators 14 and 64 and
the second current generators 24 and 74 were kept operating. The
third current generators 34 and 84 made an electric current of 0.5
.mu.A flow through each of the cathode electrodes 3 and the
comparative cathode electrodes 5. After 30 minutes from the
activation of the third current generators 34 and 84, or after 48
hours and 30 minutes from the activation of the first current
generators 14 and 64 and the second current generators 24 and 74,
the magnitude of the electric current provided by the third current
generators was changed every 30 minutes by electric current
changers 35 and 85. A series of changes of the electric current was
conducted on a one-hour cycle, beginning at the activation of the
third current generators 34 and 84.
[0073] Since the magnitude of the electric current provided by the
first current generators 14 and 64 and that of the electric current
provided by the second current generators 24 and 74 are larger than
the magnitude of the electric current provided by the third current
generators 34 and 84, electric currents always flowed into the
cathode electrodes 13, 63, 23, and 73 where the cathode reaction
always occurred while the electric current was being provided by
the third current generators 34 and 84.
[0074] While the third current generators 34 and 84 were providing
the electric current, the potential difference across the first
cathode electrode 13 and the second cathode electrode 23 and that
across the first comparative cathode electrode 63 and the first
comparative cathode electrode 73 were continuously measured. The
results are shown in FIG. 5. The potential difference in the first
half, or the first 30 minutes, of each cycle, had positive values,
while the potential difference in the latter half, or the latter 30
minutes, of each cycle, had negative values. The average of the
values of the potential difference in the first 30 minutes and that
of the values of the potential difference in the last 30 minutes
were respectively calculated. The results are shown in Table 1
below. In FIG. 5, the zero on the axis of abscissas, or the axis of
the elapsed time, denotes the point when the operation of the third
current generators 34 and 84 was begun.
[0075] In addition, the electrical resistance, which may be called
"polarization resistance" hereinafter, of the cathode electrodes 3
or 53 was calculated for each cycle. The following equation was
used for the calculation:
R.sub.p1=(V.sub.1+-V.sub.1-)/2I-R (5)
[0076] R.sub.p1: polarization resistance in each cycle
[0077] V.sub.1+: average of the values of the potential difference
in the first 30 minutes
[0078] V.sub.1-: average of the values of the potential difference
in the last 30 minutes
[0079] I: magnitude of the electric current that was made to flow
through the cathode electrodes by the third current generator
[0080] R: resistance of the solution between the pair of cathode
electrodes
[0081] The resistance of the solution between the pair of cathode
electrodes was automatically decided depending on the distance
between the cathode electrodes and whether the solution had been
treated or untreated.
[0082] In equation (5) above, the entire resistance is calculated
according to "(V.sub.1+-V.sub.1-)/2I". The subtraction of "R", the
electrical resistance of the solution, from the entire resistance
provides "R.sub.p1", the electrical resistance of only the cathode
electrodes.
[0083] The polarization resistance of each cycle and the average of
the polarization resistances of all the cycles are shown in Table 1
below. In addition, the ratio of the average of the resistances of
the cathode electrodes immersed in the treated water to the average
of the resistances of the comparative cathode electrodes immersed
in the untreated water was also calculated: The result was
137.5%.
TABLE-US-00001 TABLE 1 1.sup.st potential difference measurement
device 2.sup.nd potential difference measurement device (for
treated water) (for un-treated water) Average Average Polarization
Average Average Polarization voltage (mV) voltage (mV) resistance
voltage (mV) voltage (mV) resistance for +0.5 .mu.A for -0.5 .mu.A
(k.OMEGA.) for +0.5 .mu.A for -0.5 .mu.A (k.OMEGA.) 1.sup.st cycle
170.58 -350.51 519.00 159.01 -241.88 398.80 2.sup.nd cycle 157.22
-298.26 453.37 203.36 -179.57 380.84 3.sup.rd cycle 216.44 -279.99
494.33 138.55 -184.84 321.30 4.sup.th cycle 198.03 -363.43 559.35
110.34 -218.23 326.49 5.sup.th cycle 210.01 -207.42 415.32 130.57
-200.00 328.48 6.sup.th cycle 171.21 -230.93 400.03 164.61 -147.46
309.98 Average 473.56 344.32 (137.5%) (100%)
[0084] As understood, the working example shows that the cathode
electrodes 3 immersed in the treated water 41 has a large
electrical resistance, compared with the comparative cathode
electrodes 53 immersed in the untreated water 42. Therefore the
experiments proved that the cathode reaction in the treated water
41 formed closer and more uniform films of calcium carbonate with a
larger proportion of calcitic crystals than the cathode reaction in
the untreated water 42 did. The formation of the calcium carbonate
films controls metal corrosion. Thus it was proven that the treated
water 41 had an enhanced antirust effect, compared with the
untreated water 42.
EXPLANATION OF REFERENCE NUMERALS
[0085] 1 determination device for determining antirust effect of
treated water [0086] 2, 12, 22, 52, 62, 72 anode electrode [0087]
3, 13, 23, 53, 63, 73 cathode electrode [0088] 11 first potential
difference measurement device [0089] 14, first current generator
[0090] 24, 74 second current generator [0091] 34, 84 third current
generator [0092] 35, 85 electric current changer [0093] 36, 86
measurement and output device [0094] 41 treated water [0095] 42
untreated water [0096] 61 second potential difference measurement
device [0097] 91 determiner [0098] 92 power supply [0099] 93, 94
current transducer [0100] 95 control circuit [0101] 96 flip-flop
controller [0102] 102 water treatment device [0103] 103 piping
[0104] 104, 105 three-way valve
* * * * *
References