JP4870043B2 - Fluid supply device and boiler water-containing component concentration measuring device - Google Patents

Description

  The present invention relates to a fluid supply device and a boiler water-containing component concentration measuring device equipped with the fluid supply device, and more specifically, used for analyzing a specific component concentration in a small amount of liquid, for example, 10 mL or less. A fluid supply device in which the chemical solution or sample solution is not inadvertently dropped into the reaction cell after the chemical solution or sample solution is supplied to the reaction cell, and the specific component content in the boiler water by incorporating this fluid supply device It is related with the boiler water containing component density | concentration measuring apparatus which can measure accurately.

  As a method for measuring the concentration of a component contained in an aqueous solution, an absorptiometric method using a coloring reaction between a substance to be measured and a coloring reagent is known. In this absorptiometry, a substance to be measured contained in an aqueous solution is reacted with a coloring reagent, the aqueous solution is colored with the generated compound, and then light emitted from a light source is passed through the colored aqueous solution. The transmitted light is received by the light receiving element, and the absorbance or light transmittance of the colored aqueous solution is measured based on the electrical signal output from the light receiving element, thereby obtaining the concentration of the component contained in the aqueous solution. it can.

  Furthermore, for example, when measuring the concentration of ionic silica contained in a trace amount in boiler water, molybdenum blue absorptiometry is used. In molybdenum blue absorptiometry, several kinds of coloring reagents are sequentially injected into a reaction cell that stores the collected boiler water.

  So far, the measurement of the ionic silica concentration contained in boiler water has been carried out by manual analysis. An analysis method called manual analysis is to extract a predetermined amount of boiler water from a piping system that circulates the boiler water, and measure the concentration of ionic silica contained in the boiler water by applying the molybdenum blue absorptiometry to the extracted boiler water. It is a technique to do.

  As can be easily guessed, measurement of the ionic silica concentration in boiler water by such manual analysis takes time and causes a time lag. Accordingly, there is a problem that the quality of boiler water cannot be controlled by measuring the ionic silica concentration in the boiler water every moment.

In order to solve this problem, a silica concentration automatic measuring device capable of measuring the ionic silica concentration in boiler water in a short time is desired. In recent years, there has been a demand for a compact silica concentration automatic measuring device that requires a small volume of boiler water to be collected.
As an apparatus for automatically measuring the silica concentration, for example, an apparatus for injecting a predetermined amount of reagent with a plunger pump or a bellows pump into a reaction cell having a predetermined amount of sample liquid extracted from a boiler pipe for circulating boiler water is assumed. The

  The plunger pump and bellows pump are large-sized devices. Accordingly, it is not possible to reduce the size of the silica concentration automatic measuring apparatus that employs the plunger pump and the bellows pump.

  As a mechanism for supplying a reagent to a reaction cell in a silica concentration automatic measuring device, a reagent tank for storing the reagent, a pressurizing means for injecting a pressurized gas into the reagent tank, and a reagent in the reagent tank are transferred to the reaction cell. A reagent supply means including a fluid flow path and an electromagnetic valve interposed in the middle of the fluid flow path is assumed. When employing a reagent supply means having a pressurizing means, the apparatus configuration is complicated because the piping system and the reagent tank need to have an airtight structure so that the pressurized gas can be injected into the reagent tank at a predetermined pressure. Become. In addition, since the pressurized gas that is press-fitted into the reagent tank must be clean, equipment for purifying the gas is required. As a result, it is difficult to reduce the size of a silica concentration automatic measuring device that employs a method of press-fitting pressurized gas into a reagent tank.

  It is envisaged that a rotary pump is employed in the silica concentration automatic measuring device to supply the reagent to the reaction cell. However, since the rotary pump is worn at the rotary part, for example, the bearing part of the rotary shaft, it is necessary to periodically replace parts, and there is a concern of liquid leakage from the seal part of the rotary pump.

  In a small-sized automatic measuring device for silica concentration, it is important that boiler water and a chemical solution as sample solutions are accurately supplied into a reaction cell. In particular, when the internal volume of the reaction cell is 10 mL or less, the allowable fluctuation range of the supply amount of the sample solution and the chemical solution is required to be about ± 3 to 5%.

  An object of the present invention is that a chemical solution or a sample solution flowing through a fluid flow path can be accurately supplied to a reaction cell at a desired volume, and a droplet of the chemical solution or the sample solution is involuntarily in the reaction cell after the supply. An object of the present invention is to provide a small fluid supply device that is not supplied. Another object of the present invention is to provide a small boiler water-containing component concentration measuring device capable of measuring the concentration of components contained in boiler water with a small amount of sample liquid collected from boiler water.

As means for solving the problems,
Claim 1
“A sample solution or chemical solution collected from boiler water can be mixed, but the sample solution or chemical solution is circulated through a reaction cell having an internal volume of at most 10 mL, and the opening opens into the reaction cell. A fluid flow path having a cross-section of 0.2 to 0.8 mm ² ;
A pump that is disposed in the middle of the fluid flow path, and that transfers a sample liquid or a chemical liquid existing in the fluid flow path to the reaction cell by driving a piezoelectric element;
A flow path opening / closing valve disposed in the middle of the fluid flow path from the pump to the reaction cell;
A fluid supply device characterized by comprising:
Claim 2
“The fluid supply device according to claim 1, wherein the flow path opening / closing valve is a solenoid valve”,
Claim 3
“The fluid supply device according to claim 1 or 2, wherein the fluid flow channel is a chemical flow channel for flowing a chemical solution, and the flow channel opening / closing valve is a chemical flow channel opening / closing valve;
A boiler water storage tank in which the collected boiler water is arranged at a position higher than the reaction cell, a boiler water supply flow path for deriving the boiler water in the boiler water storage tank to the reaction cell, and the boiler water supply flow path A sample liquid supply device provided with a boiler water supply flow path opening / closing valve interposed in the middle of
A light emitting element that emits light into the reaction cell and a light receiving element that receives the light emitted from the light emitting element and outputs an electrical signal;
Output means for outputting the concentration of a specific component in the boiler water based on the electrical signal output from the light receiving element;
A boiler water-containing component concentration measuring device characterized by comprising:
Claim 4
"The boiler water-containing component concentration measuring device according to claim 4, wherein the output means includes a calculation means for calculating the concentration of the specific component in the boiler water and a display means for displaying the concentration of the specific component". It is.

A fluid supply device according to the present invention is provided in a reaction cell having an internal volume of at most 10 mL, from a fluid flow channel having an opening cross-sectional area of a fluid flow channel opening in the reaction cell of 0.2 to 0.8 mm ^2. , Supplying a sample solution collected from a chemical solution or boiler water. When a fluid such as a sample solution or a chemical solution is supplied to a reaction cell having such an internal volume from a fluid channel having the opening cross-sectional area, in this invention, a pump that operates by driving a piezoelectric element and a channel opening / closing The valve supplies and stops supplying fluid to the reaction cell. By stopping the driving of the piezoelectric element without using the flow path opening / closing valve, when the supply of fluid from the fluid flow path having the opening cross-sectional area is stopped in the reaction cell having an internal volume of at most 10 mL, Even after the fluid droplets remain in the opening of the fluid flow path and the supply of the fluid is stopped, the fluid droplets drop involuntarily from the opening of the fluid flow path into the reaction cell. However, according to the present invention, the fluid supply from the fluid channel opening to the reaction cell is stopped by the fluid channel closing operation by the channel opening / closing valve. And no fluid droplets remain. Therefore, after the fluid supply to the reaction cell is stopped, the fluid existing in the opening of the fluid flow path is not involuntarily supplied into the reaction cell. Thus, in the fluid supply apparatus according to the present invention, the advantage that the liquid droplet is not inadvertently supplied into the reaction cell after the supply of the fluid to the reaction cell is stopped is due to the driving of the piezoelectric element. This is a significant advantage that cannot be achieved when using only a working pump to supply and stop fluid supply to the reaction cell. According to the present invention, when a fluid is supplied to a reaction cell having an internal volume of 10 mL or less by a fluid channel having the opening cross section, a combination of a small pump driven by a piezoelectric element and a channel opening / closing valve, Provided is a fluid supply device that does not involuntarily drop fluid from an opening of a fluid flow path.

  In the fluid supply apparatus according to the present invention, the pump using the piezoelectric element exists in the fluid flow path on the upstream side by the diaphragm formed so as to be reciprocally movable by driving the piezoelectric element, and by the reciprocating motion of the diaphragm. And a pump chamber for sucking the sample liquid or the chemical liquid and discharging the sample liquid or the chemical liquid into the fluid flow path on the downstream side, and when a solenoid valve is employed as the flow path opening / closing valve, The fluid breakage at the opening is particularly good, and after the supply of fluid to the reaction cell is stopped, fluid droplets do not involuntarily fall into the reaction cell from the fluid opening. Therefore, a color reaction by mixing a sample solution and a chemical solution of 10 mL or less, particularly 5 mL or less, in a reaction cell having an internal volume of 10 mL or less can be performed stoichiometrically accurately. In a color reaction at a large volume in a reaction cell having an internal volume far exceeding 10 mL, even if a droplet drops involuntarily from the opening of the fluid flow path, the large influence on the color reaction is negligible. However, in consideration of the involuntary drop that occurs in the color reaction that is performed at a volume of 10 mL or less, the color reaction is greatly affected. The absence of involuntary drop dropping in the reaction cell is regarded as a great advantage when performing accurate concentration measurements.

  In the boiler water-containing component concentration measuring apparatus according to the present invention, the supply of fluid, for example, sample liquid or chemical liquid into the reaction cell is executed by a combination of a pump using a piezoelectric element and a flow path opening / closing valve. There is no involuntary droplet dropping from the opening of the fluid flow path after stopping the supply of fluid, for example, sample liquid or chemical liquid, into the reaction cell having an internal volume of 10 mL or less. The active ingredient concentration can be accurately measured.

Embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing a chemical liquid supply apparatus which is an example of a fluid supply apparatus according to the present invention. FIG. 2 is a schematic diagram showing a pump using a piezoelectric element, which is an example of the pump according to the present invention. FIG. 3 is a schematic view showing an ionic silica concentration measuring apparatus which is an example of a boiler water-containing component concentration measuring apparatus according to the present invention.

As shown in FIGS. 1 and 3, the chemical solution supply apparatus 1 is connected to a chemical solution tank 2 for storing a chemical solution and a reaction cell 14, and transfers the chemical solution from the chemical solution tank 2 to the reaction cell 14. A chemical liquid transfer channel 3 that is an example of a fluid flow path that can be used, and a pump using a piezoelectric element that is interposed in the middle of the chemical liquid transfer flow path 3 and is an example of a pump in the present invention that uses a piezoelectric element 4 and an electromagnetic valve 5 that is an example of a channel opening / closing means that is interposed downstream of the pump 4 in the chemical solution transfer channel 3.
The reaction cell 14 has an internal volume of 10 mL or less, particularly 5 mL or less. The reason why such a small-capacity reaction cell 14 is used is to accommodate a small-volume sample solution.

Inside the reaction cell 14, an opening of the chemical liquid transfer channel 3 that supplies the chemical liquid stored in the chemical tank 2 into the reaction cell 14 is disposed. The opening cross-sectional area of the opening of the chemical liquid transfer channel 3 is 0.2 to 0.8 mm ² . For example, a chemical solution is supplied into the reaction cell 14 at a flow rate of 0.4 to 1.0 mL / sec from the opening having such an opening cross-sectional area. With such a small amount of chemical solution supply, the stoichiometric reaction between the chemical solution and the sample solution proceeds accurately in the reaction cell 14 after the supply of the chemical solution into the reaction cell 14 is completed. In any case, involuntary dripping of the chemical solution from the opening of the chemical solution transfer channel 3 is absolutely prohibited. As shown in FIG. 3, a sample transfer channel 15 for supplying a sample solution to the reaction cell 14 is coupled to the reaction cell 14, and the end opening of the sample transfer channel 15 is in the reaction cell 14. Open above.

The pump 4 according to the present invention is formed so that the chemical liquid in the chemical liquid transfer channel can be sucked and discharged by driving the piezoelectric element to transfer the chemical liquid in the chemical liquid transfer channel to the reaction cell 14. .
As shown in FIG. 2, the pump 4 includes an inlet channel 6 connected to the chemical liquid transfer channel 3, an inlet valve 7, a pump chamber 8, an outlet valve 9, and an outlet flow connected to the chemical solution transfer channel 3. A voltage is applied to the diaphragm portion 11 having a flexible diaphragm thin film for changing the pressure in the passage 10 and the pump chamber 8, the disk-like piezoelectric element 12 serving as a driving means for the diaphragm portion 11, and the piezoelectric element 12. Power source (not shown).
The piezoelectric element 12 is made of a piezoelectric material that generates vibration and expansion and contraction when a voltage is applied thereto.

An outline of the operation of the pump 4 using the piezoelectric element according to one embodiment of the present invention will be described.
As shown in FIG. 2, when an AC voltage is applied to the piezoelectric element 12, the piezoelectric element 12 expands and contracts in the peripheral portion direction, and the diaphragm thin film in the diaphragm portion 11 also expands and contracts. At this time, the diaphragm thin film in the diaphragm portion 11 bends in a direction perpendicular to the surface of the diaphragm portion 11, and the diaphragm thin film in the diaphragm portion 11 bends outwardly from the pump chamber 8 and the diaphragm thin film in the diaphragm portion 11. Repeats the operation of bending in a concave shape inside the pump chamber 8. That is, the diaphragm thin film in the diaphragm portion repeats reciprocation between the convex curve and the concave curve. By such reciprocation of the diaphragm thin film in the diaphragm portion 11, the internal volume of the pump chamber 8 changes. When the internal volume of the pump chamber 8 increases and the inside of the pump chamber 8 becomes negative pressure, the outlet valve 9 is closed and the inlet valve 7 is opened, whereby the chemical solution is sucked into the pump chamber 8 from the inlet channel 6. When the internal volume of the pump chamber 8 is reduced and the pressure in the pump chamber 8 becomes positive, the inlet valve 7 is closed and the outlet valve 9 is opened, whereby the chemical solution in the pump chamber 8 is discharged from the outlet channel 10. By performing such an operation, a minute amount of liquid can be transferred.

  In the chemical solution supply apparatus 1 according to one embodiment of the present invention, the piezoelectric element 12 is used as the driving means, so that the structure is simplified, and as a result, a long-life and small-sized pump can be obtained. Moreover, there is an advantage that the power consumption is low and the closed operation can be performed. If a small pump is used, the chemical supply device can be reduced in size, and a very small amount of chemical solution can be supplied. Therefore, the reaction cell for injecting the chemical solution can also be reduced in size. The entire boiler water-containing component concentration supply device incorporating the device 1 can be reduced in size.

  In FIG. 1, a solenoid valve 5 is used as an embodiment of the flow path opening / closing means. Since the solenoid valve has a fast response speed to ON / OFF in energization to the solenoid valve, the chemical solution transfer channel can be quickly opened and closed. Therefore, an electromagnetic valve is preferable as the channel opening / closing means. Examples of the solenoid valve include a diaphragm solenoid valve and a piston solenoid valve. However, in the present invention, the flow path opening / closing means may be various other than the electromagnetic valve as long as the chemical liquid in the chemical liquid transfer flow path 3 can be circulated or stopped by opening and closing the chemical liquid transfer flow path 3. The following means can be adopted. Examples of the channel opening / closing means other than the electromagnetic valve include a pinch valve. The pinch valve is formed so as to close the flow path by pressing the chemical transfer path and to stop the flow of the chemical liquid in the chemical transfer path, and to open the flow path It is formed so that a chemical solution can be circulated in the chemical solution transfer channel.

  Examples of the chemical solution include a solution in which a reagent used in an analysis device or a test device is dissolved.

The chemical transfer channel 3 is not particularly limited as long as it is a commonly used channel for transferring liquid. The material of the chemical solution transfer channel, the cross-sectional area of the chemical solution, the channel length, etc. are appropriately selected in consideration of the type of the chemical solution to be transferred through the chemical solution transfer channel, for example, the viscosity, corrosivity, and discharge amount of the chemical solution. be able to.
An injection nozzle can be attached to the end of the chemical liquid transfer channel 3 where the chemical liquid is discharged, if necessary. This injection nozzle is used to facilitate attachment to the reaction cell and / or to improve the breakage of the liquid droplets of the chemical solution, and the material and shape of the injection nozzle can be appropriately selected. Even when the discharge nozzle is provided, since the discharge nozzle forms a part of the chemical liquid transfer channel 3, the opening of the discharge nozzle has an opening cross-sectional area of 0.2 to It needs to be 0.8 mm ² .

  The chemical tank 2 is not particularly limited as long as it is a tank that is normally used for storing a chemical. The material and capacity of the chemical solution tank can be appropriately selected in consideration of the corrosiveness of the chemical solution, the amount used, and the like.

The operation of the chemical solution supply apparatus 1 shown in FIG. 1 will be described below.
As shown in FIG. 1, the chemical liquid transfer channel 3 includes a pump 4 using a piezoelectric element and an electromagnetic valve 5 in this order along the downstream side from the chemical liquid tank 2, as shown in FIG. 2. Then, the chemical solution is transferred from the chemical solution tank 2 connected to the chemical solution transfer channel 3 by the pump 4 using the piezoelectric element 12, and the chemical solution is reacted from the end opening of the chemical solution transfer channel 3 as shown in FIG. The cell 14 is discharged. When stopping the injection of the chemical liquid, the chemical liquid flow path 3 is closed by the electromagnetic valve 5 to stop the distribution of the chemical liquid.

  The pump 4 using the piezoelectric element 12 can always be operated even when the electromagnetic valve 5 is closed. Therefore, since the time and flow rate of the chemical solution injected into the reaction cell 14 can be adjusted only by opening and closing the electromagnetic valve 5, the operation is simple.

  Further, when the pump 4 using the piezoelectric element 12 is always in an operating state, the chemical solution transfer channel 3 is always filled with the chemical solution, and is in a standby state so that the chemical solution can be circulated at a constant flow rate. Yes. Furthermore, the electromagnetic valve 5 can quickly open and close the flow path. Therefore, if the electromagnetic valve 5 is opened, the chemical liquid can be circulated immediately at a constant flow rate, and if the electromagnetic valve 5 is closed, the flow of the chemical liquid can be stopped quickly, so that the electromagnetic valve 5 is opened for a predetermined time. By doing so, a predetermined amount of chemical liquid can be discharged accurately. Even if the electromagnetic valve 5 is closed while the pump 4 is being driven, the pump 4 is driven by the piezoelectric element 12, so that the impact caused by the driving of the pump 4 that continues to be driven causes the end opening of the chemical transfer passage 3. Therefore, the liquid droplet is not inadvertently dropped into the reaction cell 14 from the end opening of the chemical liquid transfer channel 3 that opens into the reaction cell 14. Accordingly, an accurate amount of the sample solution and an accurate amount of the chemical solution are supplied into the reaction cell 14, and the stoichiometric chemical reaction proceeds to accurately measure the concentration of the component contained in the sample solution. Can be done.

  Furthermore, the combination of the pump 4 using the piezoelectric element 12 and the electromagnetic valve 5 improves the cutting of the chemical solution at the end of the chemical solution transfer channel 3 after the chemical solution has stopped flowing through the chemical solution transfer channel 3. Therefore, there is no problem that a liquid droplet remains at the end of the chemical liquid transfer channel 3 and this liquid droplet is involuntarily dropped into the reaction cell.

  Furthermore, the pump 4 using a piezoelectric element does not need to prepare a special tank that can withstand pressurization, unlike means for transferring chemical liquid by supplying air to the chemical liquid tank. Moreover, it is not necessary to bleed the pump unlike a centrifugal pump. In addition, unlike a plunger pump, it does not require a drive source such as a motor, a control circuit, and a liquid leakage prevention measure. Therefore, the pump can be reduced in size, so that the entire chemical supply device can be reduced in size. it can. Further, unlike a rotary pump, there is no rotating part such as a motor or a bearing, so there is an advantage that maintenance such as periodic replacement of parts is not required.

The chemical solution supply apparatus according to the present invention can be used when measuring the concentration of ionic silica in water, for example, in boiler water by molybdenum yellow absorptiometry and molybdenum blue absorptiometry (JIS B 8224).
In the above, an example of the chemical liquid supply apparatus according to the present invention has been described. However, the chemical liquid supply apparatus according to the present invention is not limited to the chemical liquid supply apparatus described above. In the chemical liquid supply apparatus described above, the fluid flow path is the chemical liquid transfer flow path, but the fluid flow path may be a flow path through which the sample liquid collected from the boiler water flows, that is, the sample transfer flow path.

FIG. 3 is a schematic view showing an example of a boiler water-containing component concentration measuring device according to the present invention, which includes the chemical solution supply device 1.
The ends of the chemical liquid transfer channels 3a, 3b, and 3c of the chemical liquid supply apparatus 1 according to the embodiment of the present invention are connected to the reaction cell 14, and the chemical liquid in the chemical liquid tank (not shown) is transferred to the chemical liquid transfer flow. It flows through the passages 3a, 3b, 3c and is injected into the reaction cell 14. In this example, the three chemical liquid transfer channels 3a, 3b, 3c are provided because it is necessary to supply three types of chemical liquids to the reaction cell 14.
A sample transfer channel 15 is connected to the reaction cell 14, and a sample tank (not shown) is connected to the end of the sample transfer channel 15. The sample water in the sample tank flows through the sample transfer channel 15 and is injected into the reaction cell 14. In addition, a sample tank stores the boiler water extract | collected, for example from boiler piping (not shown), and is installed in the position higher than the said reaction cell 14. FIG. A channel opening / closing valve (not shown) is interposed in the middle of the sample transfer channel 15. Therefore, when the flow path opening / closing valve interposed in the middle of the sample transfer flow path 15 is opened, the sample liquid stored in the sample tank can be transferred to the reaction cell 14 by the head pressure. When the sample liquid is boiler water, the sample tank is also referred to as a boiler water storage tank, the sample transfer channel 15 is also referred to as a boiler water supply channel, and the channel on / off valve is also referred to as a boiler water supply channel on / off valve. .
A waste liquid pipe 16 is connected to the bottom of the reaction cell 14, and after the sample water and the chemical liquid are mixed, the mixed liquid is discharged from the waste liquid pipe 16.

  In the reaction cell 14, a light source 17 that emits light so as to pass through the liquid in the reaction cell 14, for example, a light emitting element, and a light receiving element 18 that receives light that has passed through the liquid are included in the reaction cell 14. Alternatively, the calculation unit 19 is installed so as to sandwich the reaction cell 14 and calculates the concentration of ionic silica in the sample water based on an electric signal (also referred to as a detection signal) output from the light receiving element 18. Display means (not shown) for displaying the concentration of ionic silica calculated by the calculation unit 19, for example, a liquid crystal screen, a CRT, a printer, and the like are provided. In the present invention, the calculation unit 19 and the display means form the output means in the present invention.

  The reaction cell 14 according to the present invention is not particularly limited as long as it has a shape such as a columnar shape, a rectangular parallelepiped shape, a spherical shape, or a conical shape that can completely mix the sample water and the chemical solution. When mixing using a stirrer such as a stirrer, a shape having a flat bottom surface is preferable. In this example, the stirrer is a stirrer that is rotated by the magnetic force of the driving source existing outside the reaction cell. However, in the present invention, the stirrer is not limited to this stirrer, and mechanical force by the driving source is used. It may be a stirrer in which a stirring blade is provided on a rotating shaft that rotates.

  The material of the reaction cell 14 is not particularly limited. If a spectrophotometer is provided so as to sandwich the reaction cell 14 and the absorbance or transmittance of the liquid in the reaction cell 14 is measured, ionic silica and It is preferable that the material does not absorb the color exhibited by the reaction product obtained as a result of the reaction with the chemical solution, for example, a material that does not absorb light from around 400 nm which is the yellow wavelength band to around 800 nm which is the blue wavelength band, Examples thereof include quartz glass and plastic.

The internal volume of the reaction cell 14 in the present invention is an important factor in the present invention. This is because it is necessary to meet the demand for downsizing the boiler water-containing component concentration measuring device. The internal volume of the reaction cell 14 in the present invention is at most 10 mL, and particularly at most 5 mL. Measuring the ionic silica concentration using a sample solution collected in a volume of 5 mL or less from the boiler water collected from the boiler water pipe is a request for measuring the ionic silica concentration in recent years. Thus, a reaction cell having a small internal volume can suitably meet the above-mentioned requirements.
In order to accurately measure the concentration of ionic silica, it is necessary to completely react ionic silica in the sample water with the chemical solution. When the volume of the reaction cell 14 is larger than 10 mL, the amount of the chemical solution injected into the reaction cell 14 fluctuates, and the liquid remaining at the end of the chemical solution transfer channel after a predetermined time has elapsed after stopping the chemical solution injection. Dropping of the droplet does not cause a problem because it falls within the measurement error range. However, downsizing of the boiler water-containing component concentration measuring device 13 is desired, and when the reaction cell 14 is downsized, the reaction cell 14 is downsized. It is the content of the reaction cell 14 that the liquid droplets remaining in the openings in the reaction cells 14 of the chemical solution transfer channels 3a, 3b, and 3c involuntarily fall after the change in the injection amount of the chemical solution and the injection of the chemical solution are stopped. It becomes larger at a ratio that cannot be ignored compared to the product. In that case, when the chemical solution supply apparatus according to the present invention is used, a predetermined amount of the chemical solution can be accurately injected, and even after the injection of the chemical solution is stopped, the opening ends of the chemical solution transfer channels 3a, 3b, 3c Since the droplets remaining in the sample liquid do not fall involuntarily, the ionic silica in the sample water and the chemical solution can be reacted stoichiometrically accurately. Therefore, since the ionic silica contained in the sample water and the chemical solution can be completely reacted, the boiler water-containing component concentration measuring device 13 is small and can accurately measure the concentration of the ionic silica. Is provided.

Here, as described in JIS B 8224, the ionic silica contained in the sample water is “silica that produces yellow of a heteropoly compound produced by reaction with hexaammonium heptamolybdate” or the like. Can be mentioned.
As a chemical solution for measuring the concentration of ionic silica contained in boiler water, an ammonium molybdate solution, oxalic acid, and an ascorbic acid solution are used. The ammonium molybdate solution is defined in JIS K 8905, the oxalic acid is defined in JIS K 8519, and the ascorbic acid solution is defined in JIS K 9502.

  The boiler water-containing component concentration measuring apparatus 13 according to the present invention is used when measuring the ionic silica concentration in water, for example, in boiler water by the molybdenum yellow absorptiometry and the molybdenum blue absorptiometry (JIS B 8224). Can do. By using the boiler water-containing component concentration measuring device 13 to measure the light absorbance or transmittance of the liquid obtained by completely reacting the ionic silica in the sample water with the chemical solution, the ionic state in the water is measured. The silica concentration can be measured. As shown in FIG. 3, the spectrophotometer measures the ionic silica concentration by a calculation unit 19 based on detection signals output from a light source 17 such as a light emitting element and a light receiving element 18 such as a light receiving element and a light receiving element 18. can do. The light emitted from the light source 17 passes through the liquid in which ionic silica and the chemical liquid are completely reacted, and reaches the light receiving element 18. Either molybdenum yellow absorptiometry or molybdenum blue absorptiometry can be employed to measure the concentration of ionic silica. In the molybdenum yellow absorptiometry, silica is quantified by measuring the yellow absorbance of a heteropoly compound produced by the reaction of ionic silica with hexaammonium heptamolybdate. In the molybdenum yellow absorptiometry using a light receiving element, the absorbance or transmittance near a wavelength of 400 nm is measured, whereby the silica concentration is calculated by the calculation unit. In the molybdenum blue absorptiometry, the silica concentration is calculated by the calculation unit 19 by measuring the absorbance or transmittance around a wavelength of 800 nm. In the molybdenum blue absorptiometry, the heteropolyacid produced by the reaction of ionic silica with hexaammonium heptamolybdate is reduced with oxalic acid and ascorbic acid to convert it into molybdenum blue, and the absorbance of this molybdenum blue is measured.

  As shown in FIG. 3, the light emitting element and the light receiving element may be provided so as to sandwich the reaction cell 14, may be provided so as to sandwich the waste liquid pipe 16, or may be measured downstream of the waste liquid pipe 16. A cell may be provided so as to sandwich the measurement cell.

  Next, a method for analyzing the concentration of ionic silica will be described.

  First, sample water heated to 25 to 45 ° C. is injected into the reaction cell 14 from the sample water flow path 15 for a predetermined time. This is because by heating the sample water, the reaction between the substance in the sample water and the chemical solution can be promoted, so that the total measurement time can be shortened and a rapid analysis is realized. At this time, while rotating the stirrer, a solenoid valve (not shown) is intermittently opened and closed to clean the reaction cell and the waste liquid tube.

  Next, the injection of the sample water and the rotation of the stirrer are stopped, the electromagnetic valve is closed, and an appropriate amount of the sample water is held in the reaction cell. Thereafter, an appropriate amount of a mixed solution of the chemical solution X and sulfuric acid is injected from the chemical solution transfer channel 3a, and mixed by rotating the stirrer. As this chemical solution X, an ammonium molybdate solution can be mentioned, and ionic silica and phosphate ions in the sample water are reacted with ammonium molybdate to color the sample water yellow. At this time, ionic silica and ammonium molybdate react, and in parallel with this reaction, phosphate ions and ammonium molybdate react to produce two types of compounds each having a yellow color in the sample water. Therefore, the concentration of ionic silica cannot be calculated from the absorbance of the sample liquid that exhibits a yellow color.

Therefore, the rotation of the stirrer is temporarily stopped, a predetermined amount of the chemical solution Y is injected into the reaction cell from the chemical solution transfer channel 3b, and the stirrer is rotated again to mix. An example of the chemical solution Y is an oxalic acid solution. Addition of oxalic acid solution causes yellow color due to the reaction product of phosphate ion and ammonium molybdate to disappear when oxalic acid reacts with the reaction product of phosphate ion and ammonium molybdate that had been yellow. . Therefore, when the absorbance or transmittance of the reaction product liquid colored yellow by the light emitting element and the light receiving element is measured, the concentration of ionic silica in the sample water can be measured.
In the present invention, since a reaction cell having an internal volume of 10 mL or less is employed, the ionic silica concentration in the high concentration range of 2 to 20 mg / L can be measured. The measurement method so far is based on the molybdenum yellow absorptiometry. That is, when ionic silica is contained in boiler water at a high concentration, molybdenum yellow absorptiometry is suitable.

Furthermore, when measuring a low concentration ionic silica concentration, next, a predetermined amount of the chemical solution Z is injected from the chemical solution transfer channel 3c, and the sample water and the chemical solution are sufficiently mixed. As this chemical | medical solution Z, an ascorbic acid solution can be mentioned. When the ascorbic acid solution is added to the yellow reaction product solution, which is generated by adding ammonium molybdate to the boiler water sample solution, the reaction product of ionic silica and ammonium molybdate and the alcohol As a result of the reaction with the acid, the reaction product liquid which has been yellowed becomes blue. The rotation of the stirrer is stopped, and after standing for a certain period of time, the light absorbance or transmittance of the reaction product liquid colored blue is measured by a spectrophotometer. Thereby, the ionic silica concentration in the concentration range of 1 to 2000 μg / L can be measured. The measurement method so far is based on the molybdenum blue absorptiometry. That is, when blue water contains ionic silica at a low concentration, the molybdenum blue absorptiometry is suitable.
After the measurement is completed, the liquid in the reaction cell is discharged.

  In the method for analyzing the concentration of ionic silica, the mixing time, the standing time, the timing of chemical solution injection, and the like can be determined as appropriate.

  When the yellow colored compound in the reaction product liquid produced by the reaction between the phosphate ion contained in the boiler water, which is the sample liquid, and the chemical liquid X remains in the reaction product liquid without completely reacting with the chemical liquid Y When this yellow coloring compound reacts with the chemical solution Z, another compound exhibiting a blue color is generated. Then, when the blue absorbance of the reaction product liquid containing the blue compound is measured in this way, the measured value obtained is erroneously output as the silica concentration. Therefore, the chemicals X, Y, Z are accurately injected into the reaction cell at a predetermined volume at a predetermined time, and as a result, the reaction between the chemicals X, Y, Z and a specific substance in the sample water is completely performed. Measurement error will be reduced.

  A boiler water-containing component concentration measuring device 13 according to an embodiment of the present invention includes a diaphragm pump using a piezoelectric element and a solenoid valve in order from an upstream side to a chemical solution transfer channel connected to a chemical solution tank that stores a chemical solution. Since the chemical solution supply device 1 is used, the chemical solutions X, Y, and Z flowing through the chemical solution transfer channels 3a, 3b, and 3c to the reaction cell 14 connected to the chemical solution supply device 1 are used. Can be accurately injected at a desired time and in a desired volume, and the liquid droplets of the chemical solution are not inadvertently dropped into the reaction cell after the injection. That is, since the chemical solution is cut off at the ends of the chemical solution transfer channels 3a, 3b, and 3c after the injection of the chemical solution into the reaction cell 14 is stopped, droplets remain at the ends of the chemical solution transfer channel and the predetermined time After the lapse, this droplet does not fall. Therefore, each time the chemical solution is sequentially injected, the ionic silica, phosphate ions and the generated compound in the sample water can be completely reacted with the chemical solution, so that the ionic silica concentration in the sample water is accurately determined. be able to. In addition, since the chemical solution supply device 1 is small and the chemical solution supply device 1 can accurately inject a desired volume of chemical solution into the reaction cell, the reaction cell can be reduced in size. The water-containing component concentration measuring device 13 can be downsized. In addition, since the chemical solution supply apparatus 1 has almost no need for maintenance, the boiler water-containing component concentration measurement apparatus 13 provided with the chemical liquid supply apparatus 1 has almost no need for maintenance.

FIG. 1 is a schematic view showing an embodiment of a chemical liquid supply apparatus according to the present invention. FIG. 2 is a schematic view of a diaphragm pump using a piezoelectric element showing an embodiment of the chemical solution transfer means according to the present invention. FIG. 3 is a schematic view showing an embodiment of a boiler water-containing component concentration measuring apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chemical solution supply apparatus 2 Chemical solution tank 3, 3a, 3b, 3c Chemical solution transfer flow path 4 Diaphragm pump 5 using a piezoelectric element Electromagnetic valve 6 Inlet flow path 7 Inlet valve 8 Pump chamber 9 Outlet valve 10 Outlet flow path 11 Diaphragm part 12 Piezoelectric element 13 Boiler water-containing component concentration measuring device 14 Reaction cell 15 Sample transfer flow path 16 Waste liquid pipe 17 Light source 18 Light receiving element 19 Calculation unit

Claims (4)

An open cross-section in which the sample solution and the chemical solution collected from the boiler water can be mixed, but the sample solution or the chemical solution is circulated through the reaction cell having an internal volume of at most 10 mL and is opened in the reaction cell. A fluid flow path of 0.2 to 0.8 mm ² ;
A pump that is disposed in the middle of the fluid flow path, and that transfers a sample liquid or a chemical liquid existing in the fluid flow path to the reaction cell by driving a piezoelectric element;
A flow path opening / closing valve disposed in the middle of the fluid flow path from the pump to the reaction cell;
A fluid supply device comprising:   The fluid supply apparatus according to claim 1, wherein the flow path opening / closing valve is an electromagnetic valve. The fluid supply apparatus according to claim 1 or 2, wherein the fluid flow path is a chemical flow path for flowing a chemical liquid, and the flow path opening / closing valve is a chemical flow path opening / closing valve;
A boiler water storage tank in which the collected boiler water is arranged at a position higher than the reaction cell, a boiler water supply flow path for deriving the boiler water in the boiler water storage tank to the reaction cell, and the boiler water supply flow path A sample liquid supply device provided with a boiler water supply flow path opening / closing valve interposed in the middle of
A light emitting element that emits light into the reaction cell and a light receiving element that receives the light emitted from the light emitting element and outputs an electrical signal;
Output means for outputting the concentration of a specific component in the boiler water based on the electrical signal output from the light receiving element;
A boiler water-containing component concentration measuring device comprising:   4. The boiler water-containing component concentration measuring apparatus according to claim 3, wherein the output means includes calculation means for calculating the concentration of the specific component in the boiler water and display means for displaying the concentration of the specific component.

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