JP2007218825A - Continuous measuring type total phosphorus meter, and operation method of continuous measuring type total phosphorus meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a continuous measuring type total phosphorus meter capable of preventing deposition of a crystal in an oxidation reactor even if a suspension period is long. <P>SOLUTION: This meter includes the oxidation reactor 21 for generating an oxidation reaction of sample water; an absorbance measuring device 22 for measuring the absorbance of the sample water subjected to the oxidation reaction; a liquid transfer means 25 for supplying a prescribed amount of the sample water, a medicine and a coloring agent to the oxidation reactor 21, and transferring the sample water subjected to the oxidation reaction to the absorbance measuring device; a sample water supply means 34 for supplying the sample water to the liquid transfer means 25; a clean water supply means 36 for supplying clean water to the liquid transfer means; and control means 22 for controlling each operation of the liquid transfer means 25, the sample water supply means 34 and the clean water supply means 36. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a total phosphorus meter for measuring the total phosphorus concentration in sample water, and more particularly to a continuous measurement type total phosphorus meter capable of continuously measuring the concentration.

  The power plant is provided with a waste water treatment device for treating boiler blow water at the time of boiler activation, drain discharged from each device, rain water, and the like. FIG. 2 is a flowchart showing a schematic configuration of the waste water treatment apparatus 1 for treating boiler blow water and the like. Boiler blow water, rainwater, and the like are temporarily stored in the water storage tank 2 and then sent to the PH adjustment tank 4 by the water storage tank pump 3. After the pH adjustment is performed here, the wastewater which is sent to the filter 8 by the filtration pump 7 and finally processed through the neutralization tank 5 and the filtration tank 6 is stored in the treated water tank 9. The treated water tank 9 includes a treated water pump 10, and treated water stored in the treated water tank 9 is pumped out by the treated water pump 10 and discharged through the discharge valve 11 and the treated water flow meter 12.

  At the same time, part of the treated water pumped out by the treated water pump 10 is sent to the treated water analyzer 13. The treated water analyzer 13 includes a total nitrogen / total phosphorus meter 14 for measuring total nitrogen and total phosphorus concentrations, a turbidity meter 15 for measuring turbidity, a COD analyzer 16 for measuring COD concentration, and a pH sensor for measuring pH. 17 and each value of treated water is continuously measured through each analyzer and sensor. Whether or not the treated water has a predetermined value is monitored through the treated water analyzer 13, and if it is determined that the treated water has not been treated to the predetermined value, the treated water is stopped from being discharged, The water is returned to the water tank 2 through the circulation valve 18.

  An example of a procedure for measuring the total nitrogen concentration of the total nitrogen / total phosphorus meter 14 that can be continuously measured in the analysis of the treated water is as follows. A predetermined amount of sample water is collected, a chemical is added thereto, and the phosphorus compound contained in the sample water is oxidized to phosphate ions while blowing air. A color former is added to this solution, and the total phosphorus concentration is determined by measuring the absorbance. When the measurement of the total phosphorus concentration is completed, the oxidation reactor and the measurement cell are cleaned. The series of operations described above is performed by the control device controlling each device according to a predetermined time chart.

  In addition, similar patent documents could not be found.

  Since the total nitrogen / total phosphorus meter 14 that continuously measures the total phosphorus concentration shown above is based on the premise of continuous measurement, if the analysis is not performed for more than one day, the oxidation reactor is separate from the above steps. It is necessary to have a cleaning process for cleaning the chemicals with chemicals. This is because, if the measurement operation is not performed for a long time, the chemicals remaining in the oxidation reactor and the components dissolved in the sample water are crystallized by the evaporation of water, and this peels off and damages the tubes, valves, etc. It is. However, there are cases where the inside of the oxidation reactor cannot be sufficiently cleaned even if a cleaning operation using this chemical is performed. In particular, in the case of total nitrogen and total phosphorus meters provided in wastewater treatment equipment that treats wastewater discharged intermittently, such as boiler blow water, the outage period may range from a few days to nearly one month. Crystals are likely to form in the reactor. While this is necessary, no effective method has been developed to address this issue.

  An object of the present invention is to provide a continuous measurement type total phosphorus meter in which crystals are not deposited in an oxidation reactor even when there is a long stoppage period. It is another object of the present invention to provide a continuous measurement type total phosphorus meter operating method in which crystals are not deposited in the oxidation reactor even if there is a long shutdown period.

  In the present invention, sample water and chemicals are quantitatively supplied to the oxidation reactor, the sample water is oxidized in the oxidation reactor, a coloring agent is added, the absorbance of this solution is measured, and the total phosphorus in the sample water is measured. A continuous measurement type total phosphorus meter for calculating the concentration, an oxidation reactor for oxidizing the sample water, an absorbance measuring device for measuring the absorbance of the oxidized sample water, and a predetermined amount to the oxidation reactor A liquid transfer means for supplying the sample water, the drug and the color former and transferring the oxidized sample water to the absorbance measuring device; a sample water supply means for supplying the sample water to the liquid transfer means; A continuous measurement type comprising water supply means for supplying clean water to the liquid transfer means, and control means for controlling the operation of the liquid transfer means, the sample water supply means, and the water supply means Total phosphorus meter.

  The present invention is also the operation method of the continuous measurement type total phosphorus meter according to claim 1, wherein the control means can supply the sample water to the oxidation reactor while the sample water supply means is in operation. When the control unit detects that the sample water supply means has stopped, the sample water is replaced with the sample water, and the clean water is controlled to be supplied to the oxidation reactor. is there.

  Further, the present invention is the operation method of the continuous measurement type total phosphorus meter according to claim 1, wherein the control means can supply the sample water to the oxidation reactor while the sample water supply means is in operation. Control, and when it is detected that the sample water supply means has stopped and a predetermined time has elapsed, the continuous water of the continuous measurement type is controlled so that the sample water can be supplied to the oxidation reactor instead of the sample water. It is the operation method of the phosphorus meter.

  Further, the present invention is the operation method of the continuous measurement type total phosphorus meter according to claim 1, wherein the control means can supply the sample water to the oxidation reactor while the sample water supply means is in operation. When the control unit detects that the sample water supply means has stopped, the continuous water type total phosphorus meter is controlled so that the clean water can be repeatedly supplied to the oxidation reactor at a predetermined interval for a predetermined time. It is a driving method.

  The continuous measurement type total phosphorus meter of the present invention supplies sample water and chemicals quantitatively to the oxidation reactor, causes the sample water to oxidize in the oxidation reactor, adds a color former, and measures the absorbance of this solution. A continuous measurement type total phosphorus meter for calculating the concentration of total phosphorus in the sample water, an oxidation reactor for oxidizing the sample water, an absorbance measuring device for measuring the absorbance of the oxidized sample water, and an oxidation reaction Liquid supply means for supplying a predetermined amount of sample water, drug and color former to the vessel, and transferring the oxidized sample water to the absorbance measuring device, and sample water supply means for supplying the sample water to the liquid transfer means, Since the water supply means for supplying the water to the liquid transfer means and the control means for controlling the operation of the liquid transfer means, the sample water supply means and the water supply means, when the sample water is not supplied, It is possible to supply clean water to the oxidation reactor Ri, without be stopped during the supply of the sample water is prolonged crystals precipitated in the oxidation reactor, it is possible to avoid the troubles caused by deposition of crystals.

  Further, according to the present invention, the control means of the continuous measurement type total phosphorus meter controls so that the sample water can be supplied to the oxidation reactor while the sample water supply means is in operation, and detects that the sample water supply means has stopped. Since the sample water is controlled to be supplied to the oxidation reactor instead of the sample water, the clean water is supplied to the oxidation reactor even when the sample water is not supplied. It is possible to prevent crystals from being precipitated. Thereby, the trouble accompanying the precipitation of crystals can be avoided.

  Further, according to the present invention, the control means of the continuous measurement type total phosphorus meter controls so that the sample water can be supplied to the oxidation reactor while the sample water supply means is activated, and the sample water supply means stops and the predetermined time is When the passage of water is detected, clean water is supplied instead of sample water, so the amount of clean water, chemicals, color former, and power used is reduced, and crystals can be prevented from efficiently depositing in the oxidation reactor. .

  According to the present invention, the control means of the continuous measurement type total phosphorus meter controls so that the sample water can be supplied to the oxidation reactor while the sample water supply means is activated, and detects that the sample water supply means has stopped. The water supply is controlled so that it can be repeatedly supplied to the oxidation reactor at predetermined intervals for a predetermined time, so that the amount of water, chemicals, coloring agent, and power used is further reduced, and crystals are more efficiently stored in the oxidation reactor. Can be prevented from precipitating.

  FIG. 1 is a diagram showing a schematic configuration of a continuous measurement type total phosphorus meter 20 as one embodiment of the present invention. The continuous measurement type total phosphorus meter 20 is used for analysis of treated water of the wastewater treatment apparatus 1 for treating boiler blow water or the like conventionally used as shown in FIG. The continuous measurement type total phosphorus meter 20 is an analyzer for measuring the concentration of phosphorus compounds such as phosphate ions and organic phosphorus in the sample water, and has an oxidation reactor 21 for oxidizing the phosphorus compounds contained in the sample water. The oxidation reaction is performed by heating and irradiating with ultraviolet rays in a state where a predetermined amount of sample water and sulfuric acid are aerated in the oxidation reactor 21. Predetermined amounts of sodium hydroxide, ammonium molybdate, and L-ascorbic acid are added to the sample water that has undergone the oxidation reaction in the oxidation reactor 21 and sent to the measurement unit 22.

  The measurement unit 22 includes a measurement cell (not shown), and the absorbance of the sample water sent to the measurement unit 22 is measured here. The absorbance data measured by the measurement unit 22 is sent to the control unit 23, and the total phosphorus concentration contained in the sample water is calculated from the absorbance measured here, and the total phosphorus concentration is calculated through the output unit 24 such as a printer or a display. The value is output. The control unit 23 includes a CPU (central processing unit) and time measuring means, and in addition to calculating the total phosphorus concentration, sends start and stop signals to each device and each part in accordance with a predetermined time chart, thereby continuously measuring type total phosphorus. A total of 20 operations are controlled.

  The sample water and various chemicals are weighed and the sample water and various chemicals are supplied to the oxidation reactor 21 through the liquid transfer means 25. The liquid transfer means 25 includes a microsyringe 26 that collects a certain amount of sample water and each drug, 8-port valves 27 and 28 that supply the sample water and various drugs to the oxidation reactor, and a pipe line 29 that is connected thereto. Has been. Various drugs such as sulfuric acid, sodium hydroxide, and ammonium molybdate are stored in a drug tank 30 (30a, 30b, 30c, 30d), and the drug tank 30 is connected to the 8-port valve 27 and the microsyringe 26 through a conduit. . After a predetermined drug is selected by the 8-port valve 27, a certain amount of drug is collected by the microsyringe 26 and sent to the oxidation reactor 21 via the other 8-port valve 28.

  In addition to colorants such as an oxidizing agent (sulfuric acid) and ammonium molybdate, chemicals include cleaning chemicals, span solutions for adjusting instruments, standard solutions, and the like. 32a, 32b, 32c). These chemicals are also sent to the oxidation reactor 21 or the measurement unit 22 through the 8-port valves 27 and 28 and the pipeline. In addition, pressurized air is sent to the oxidation reactor 21 and the microsyringe 26 via the gas purification flow rate adjustment unit 33.

  The sample water is collected through a sample water supply pump 34 that is a sample water supply means. The sample water supply pump 34 is connected to a treated water tank or the like of a wastewater treatment apparatus (not shown), and pumps the sample water such as treated water to a sample water pretreatment device 35 that can store the sample water. The sample pretreatment device 35 is connected to the 8-port valve 28 through a pipe line, and a predetermined amount of sample water is sent to the oxidation reactor 21 as with various chemicals. Further, the sample water pretreatment device 35 is connected with a water supply means 36. The water supply means 36 is for supplying fresh water to the oxidation reactor 21 in place of the sample water when the supply of the sample water is stopped as will be described later. A supply pipe 37 and a water supply valve 38 disposed in the middle of the pipe 37 are included.

  The continuous measurement type total phosphorus meter 20 having the above configuration measures the total phosphorus concentration according to the following procedure based on the signal from the control unit 23. A predetermined amount of sample water and sulfuric acid are sent to the oxidation reactor 21 via the microsyringe 26 and the 8-port valves 27, 28, etc., and then air is sent to the oxidation reactor 21 through the gas purification flow rate control unit 33. Irradiate and heat with ultraviolet rays to oxidize phosphorus compounds in sample water to phosphate ions. In parallel with the oxidation reaction operation, zero point correction of the measurement unit 22 that measures absorbance is performed. This zero point correction is performed using pure water, and after completion of the zero point correction, the pure water in the measurement cell is discharged.

  After completion of the oxidation reaction of the sample water, a predetermined amount of color former is added to the sample water, which is sent to the measurement cell of the measurement unit 22 and the absorbance is measured. The absorbance data is sent to the control unit 23, where the total phosphorus concentration of the sample water is obtained, and then the total phosphorus concentration value is output through the output unit 24. After the sample water is sent to the measurement cell, the oxidation reactor 21 is subjected to a cleaning operation using a chemical and pure water. Similarly, the cleaning operation is performed on the measurement cell that has been measured. By repeating the above operation as a unit, the total phosphorus concentration contained in the sample water can be continuously measured. When there is no sample water to be measured, the control unit 23 controls to supply clean water to the oxidation reactor 21 instead of the sample water. The water supply is operated as follows.

  The control unit 23 determines whether the sample water supply pump 34 is operating or stopped from the current value of the sample water supply pump 34 or the like. When it is detected that the sample water supply pump 34 is operating, control is performed so that the water supply valve 38 is closed. As a result, the sample water is continuously fed to the sample water pre-treatment device 35, so that the control unit 23 performs a predetermined oxidation reaction, absorbance measurement, oxidation reactor 21 and measurement to measure the total phosphorus concentration in the sample water. Repeat the series of cell washing and standby operations. On the other hand, when determining that the sample water supply pump 34 is stopped, the control unit 23 opens the water supply valve 38 and continuously supplies the water to the sample water pretreatment device 35. Since the sample water supply pump 34 is stopped, only clean water is supplied to the sample water pretreatment device 35.

  The control unit 23 outputs a signal for opening the water supply valve 38 to the water supply valve 38 and at the same time controls the liquid transfer means 25 and the like so that the oxidation reaction is performed in the oxidation reactor 21. As a result, clean water is sent to the oxidation reactor 21 instead of the sample water, and sulfuric acid is added to the clean water to carry out the oxidation reaction. Thereafter, the control unit 23 controls to repeatedly perform a series of operations of absorbance measurement, cleaning of the oxidation reactor 21 and the measurement cell, and standby similarly to the sample water. When the sample water is not supplied to the continuous measurement type total phosphorus meter 20 as described above, the continuous measurement type total phosphorus meter 20 can be continuously operated without being stopped by supplying clean water instead of the sample water.

  When the supply of sample water is stopped, the conventional continuous measurement type total phosphorus meter stops measuring the total phosphorus concentration. Therefore, if the supply of sample water is stopped for a long time, the moisture in the oxidation reactor evaporates. Crystals sometimes precipitated in the oxidation reactor. When the sample water was supplied again and the continuous measurement type total phosphorus meter started to operate, this crystal moved to the 8-port valve and the pipe line, and entered the 8-port valve and was damaged or the pipe line was blocked. In order to prevent this, the conventional continuous measurement type total phosphorus meter is provided with a cleaning step of the oxidation reactor, but this cleaning operation is not perfect. On the other hand, the continuous measurement type total phosphorus meter 20 shown in the present embodiment is supplied with clean water instead of sample water even when sample water is not supplied. Operates continuously without having to As a result, water in the oxidation reactor 21 is not evaporated and crystals are not precipitated, and troubles associated with crystal precipitation can be avoided.

  Moreover, the continuous measurement type total phosphorus meter 20 shown in this embodiment can also employ an operation method other than the above. Although the above control method prevents the crystals from being precipitated in the oxidation reactor 21 by supplying the clean water instead of the sample water immediately after the supply of the sample water is stopped, the supply of the sample water is stopped and fixed. After the time elapses, clean water may be supplied instead of the sample water. When the supply of both the sample water and the clean water is stopped, the continuous measurement type total phosphorus meter 20 enters a dormant state, but the precipitation of crystals in the oxidation reactor 21 occurs immediately after the supply of the sample water is stopped. It does not occur but occurs after the moisture in the oxidation reactor 21 evaporates, so that the clean water may be supplied before the moisture in the oxidation reactor 21 evaporates. Since the control unit 23 has time measuring means, it is only necessary to measure the time during which the sample water supply pump 34 is stopped and to control the water supply valve 38 based on the signal from this time measuring means. This makes it possible to reduce the amount of water, chemicals (including color former), and electric power used, which is economical.

  Further, after the sample water supply pump 34 is stopped and a certain time has elapsed, the supply of clean water is performed, and after supplying clean water for a fixed time, the operation of stopping the supply of clean water is repeatedly performed. Also good. Thus, even when the supply of sample water is stopped, it is possible to prevent crystals from being precipitated in the oxidation reactor 21 by intermittently supplying clean water to the oxidation reactor 21. As a result, it is possible to further reduce the use of clean water, chemicals (including color formers), and electric power, and it is possible to prevent the precipitation of crystals in the oxidation reactor 21 more efficiently.

  As described above, the continuous measurement type total phosphorus meter 20 shown in the present embodiment prevents evaporation of moisture in the oxidation reactor 21 by supplying clean water instead of sample water when the sample water is not supplied. Since the crystal is prevented from being precipitated, it is possible to effectively prevent the crystal from being precipitated in the oxidation reactor 21 with a simple configuration. In addition, when the sample water is not supplied, the continuous measurement type total phosphorus meter 20 supplies clean water instead of the sample water, and performs a series of operations from the oxidation reaction to washing and standby using the clean water. The same operation is performed with water supply, and control becomes simple. Furthermore, the continuous measurement type total phosphorus meter 20 supplies clean water instead of sample water when sample water is not supplied, and prevents the crystals from being precipitated in the oxidation reactor 21. It can be easily applied to a total phosphorus meter.

It is a figure which shows schematic structure of the continuous measurement type | mold total phosphorus meter 20 as one Embodiment of this invention. It is a flowchart which shows the schematic structure of the waste water treatment equipment 1 which processes the conventional boiler blow water.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Continuous measurement type total phosphorus meter 21 Oxidation reactor 22 Measuring part 23 Control part 25 Liquid transfer means 34 Sample water supply pump 36 Water supply means 38 Water supply valve

Claims (4)

Quantitatively supply sample water and chemicals to the oxidation reactor, oxidize the sample water in the oxidation reactor, add a color former, measure the absorbance of this solution, and calculate the total phosphorus concentration in the sample water A continuous measurement type total phosphorus meter,
An oxidation reactor for oxidizing the sample water;
An absorbance measuring device for measuring the absorbance of the oxidized sample water;
A liquid transfer means for supplying a predetermined amount of the sample water, drug and color former to the oxidation reactor, and transferring the oxidized sample water to the absorbance measuring device;
Sample water supply means for supplying the sample water to the liquid transfer means;
Water supply means for supplying clean water to the liquid transfer means;
Control means for controlling the operation of the liquid transfer means, the sample water supply means and the clean water supply means;
A continuous measurement type total phosphorus meter characterized by comprising: An operation method of the continuous measurement type total phosphorus meter according to claim 1,
The control means controls the sample water to be supplied to the oxidation reactor while the sample water supply means is in operation, and when detecting that the sample water supply means has stopped, the control means is replaced with the sample water. Is controlled so that it can be supplied to the oxidation reactor. An operation method of the continuous measurement type total phosphorus meter according to claim 1,
The control means controls the sample water to be supplied to the oxidation reactor while the sample water supply means is in operation, and detects that the sample water supply means has stopped and a predetermined time has passed. A method for operating a continuous measurement type total phosphorus meter, characterized in that, in place of water, the clean water is controlled to be supplied to the oxidation reactor. An operation method of the continuous measurement type total phosphorus meter according to claim 1,
The control means controls the sample water to be supplied to the oxidation reactor while the sample water supply means is in operation, and detects that the sample water supply means has stopped, and then supplies the clean water to the oxidation reactor. An operation method of a continuous measurement type total phosphorus meter, characterized in that control is performed so that the supply can be repeated for a predetermined time at predetermined intervals.

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