WO2017110154A1 - Ballast water control device and method for controlling ballast water treatment system - Google Patents

Abstract

Provided is a ballast water control device having a chemical liquid feed device 2 connected partway along a ballast water feed line 1, a mixing part 4 provided at a location at which a chemical liquid feed line 3 is connected, and a TRO meter 5 provided across a sampling pipe 6 connected to the terminal end 4B-side of the mixing part 4. The TRO meter 5 is capable of transmitting the result of measurement by the TRO meter 5 to a control mechanism 10. The control mechanism 10 is capable of controlling the chemical liquid feed device 2 on the basis of the value of measurement by the TRO meter 5. The position of the distal end of the sampling pipe 6 extends towards the ballast tank side by at least three times the diameter (d) of the ballast water feed line 1 from the terminal end 4B of the mixing part 4. According to this ballast water control device, it is possible to determine an optimum amount of a chorine-based killing agent to add, and to control the ballast water through a simple structure.

Description

Ballast water control device and ballast water treatment system control method

The present invention relates to a control device and a control method for controlling ballast water by optimally determining the addition amount of a chlorine-based killing agent in ballast water treatment.

In general, since ships, especially cargo ships, are designed to include the weight of cargo, etc., ships that are unloaded or lightly loaded must be able to ensure proper submersion depth and safe navigation during unloaded conditions. From the necessity, seawater is taken in the port before leaving the port to balance the ship. The water used as this ballast is called ship ballast water. When the ship ballast water leaves the port without loading, the seawater of the port is loaded into the ballast tank at the port of departure, while the ship ballast water is drained when loading in the port.

By the way, when the ship ballast water is poured and discharged by a ship that goes back and forth between the loading port and the unloading port in different environments, the difference in microorganisms contained in the ship ballast water at the loading port and the unloading port. There are concerns that it will adversely affect coastal ecosystems. Therefore, an international convention for the regulation and management of ship ballast water and sediment of ships was adopted in February 2004 at the international conference on ship ballast water management of ships, and the treatment of ship ballast water became obligatory. .

The standard set by the International Maritime Organization (IMO) as a standard for the treatment of ship ballast water is that the number of organisms (mainly zooplankton) of 50 μm or more contained in the ship ballast water discharged from the ship is less than 10 in 1 m ³ , The number of organisms (mainly phytoplankton) of 10 μm or more and less than 50 μm is less than 10 in 1 ml, the number of Vibrio cholerae is less than 1 cfu in 100 ml, the number of E. coli is less than 250 cfu in 100 ml, and the number of enterococci in 100 ml Less than 100 cfu.

In order to meet these ballast water treatment standards, a chlorinated biocide such as sodium hypochlorite or calcium hypochlorite is added to the ship's ballast water to ensure the residence time and remove microorganisms. Methods for treating ship ballast water to be killed have been proposed. The addition amount of the chlorine-based killing agent in this ballast water treatment is determined using the maximum allowable addition amount (MAD) set at the time of IMO basic approval as an index.

Thus, when adding a chlorine-based biocide to ballast water, chlorine is consumed over time, so the consumption rate of the chlorine-based active substance is calculated and the ballast water is discharged, that is, until the end of the voyage. It is desirable to add the necessary amount. Therefore, as a method for controlling such ballast water, Patent Document 1 discloses that the ballast water in the ballast water supply line to which a predetermined amount of sodium hypochlorite is supplied from the chemical solution supply apparatus is sampled, and the next in the sampled sample is obtained. It is disclosed that the decay of sodium chlorite concentration is measured and the amount of sodium hypochlorite supplied from the chemical supply device to the line is adjusted based on the measured data.

JP 2012-106224 A

However, in the method described in Patent Document 1, the ballast water in the ballast water supply line supplied with sodium hypochlorite is sampled, but the ballast water supplied with sodium hypochlorite is Immediately after mixing, the concentration is still unevenly distributed, so it must be sampled at some distance from the sodium hypochlorite supply location. For this reason, it is necessary to construct a sodium hypochlorite supply device and sampling and sodium hypochlorite concentration measuring device in two areas of the ballast water supply line embedded in the ship in a wide range, In the case where it is installed, there is a problem that not only the construction period becomes longer, but also the cost increases.

This invention solves this subject and aims at providing the apparatus for controlling the ballast water by determining the addition amount of a chlorine-type disinfectant optimally with a simple structure. Moreover, an object of this invention is to provide the control method of the ballast water using this apparatus.

In order to solve the above problems, the present invention firstly provides a ballast water supply line for supplying the taken ballast water to the ballast tank, and a chlorine-based killing treatment for killing aquatic microorganisms in the ballast water. In the ballast water treatment system, comprising: a chemical solution supply device for supplying a biocide solution to the ballast water supply line; and a mixing unit for the chlorine-based disinfectant solution provided in the ballast water supply line, the ballast water supply In the line, a sampling pipe is installed extending from the mixing section to a position at least three times away from the ballast water supply line on the ballast tank side with respect to the diameter (d) of the ballast water supply line. An oxidizing substance concentration measuring means is provided, and a control mechanism is provided for controlling the chemical solution supply device based on the measurement result of the total residual oxidizing substance concentration measuring means. To provide a control device for ballast water, characterized in that the (invention 1).

According to this invention (Invention 1), when a chlorine-based disinfectant such as sodium hypochlorite is supplied to the ballast water supply line, in order to sufficiently homogenize the concentration, the ballast is introduced from the end of the mixing section. It has been found that the length of the water supply line is required to be at least 3 times the diameter (d). Therefore, if the tip of the sampling pipe is extended to a position at least three times the ballast tank side with respect to the diameter (d) of the ballast water supply line and the ballast water is sampled from the tip of the sampling pipe, Since the concentration of the chlorine-based disinfectant is uniform, the amount of addition of the chlorine-based disinfectant can be optimally determined by measuring the total residual oxidizing substance concentration (TRO) in this ballast water. In addition, since the chemical solution supply device and the mixing unit are close to each other, it is only necessary to construct one place of the ballast water supply line by providing a sampling pipe in the vicinity of the mixing unit. Also excellent.

In the above invention (Invention 1), the diameter (d1) of the sampling pipe is preferably 1/5 or less of the diameter (d) of the ballast water supply line (Invention 2).

According to this invention (Invention 2), the area of the sampling pipe is sufficiently smaller than the area of the ballast water supply line, so that there is no hindrance to the circulation of the ballast water.

In the above inventions (Inventions 1 and 2), it is preferable that the chemical solution supply device can add a neutralizing agent when discharging the ballast water (Invention 3).

According to this invention (Invention 3), the amount of neutralizing agent added is optimally determined by collecting the ballast water when discharging from the sampling pipe and measuring the total residual oxidizing substance concentration (TRO). Can do.

In addition, the present invention secondly supplies a chlorine-based disinfectant solution for killing aquatic microorganisms in the ballast water from a chemical supply device to a ballast water supply line for supplying the ballast water taken to the ballast tank. And a ballast water treatment system control method for mixing in a mixing section provided in the ballast water supply line, wherein the ballast water supply line is changed from the mixing section to the diameter (d) of the ballast water supply line. On the other hand, ballast water is collected from the tip of the sampling pipe extending to a position separated by 3 times or more on the ballast tank side, and the total residual oxidizing substance concentration (TRO) of the collected ballast water is set near the mixing unit. Measured by the total residual oxidizing substance concentration measuring means provided, and the supply amount of the chlorine-based biocide solution is controlled based on the measurement result of the total residual oxidizing substance concentration measuring means To provide a control method for ballast water treatment system characterized Rukoto (invention 4).

According to this invention (Invention 4), when a chlorine-based disinfectant such as sodium hypochlorite is supplied to the ballast water supply line, the concentration is sufficiently homogenized from the end of the mixing section. The length (d) of the water supply line must be at least 3 times longer. Therefore, if the tip of the sampling pipe is provided to extend to a position spaced three times or more on the ballast tank side with respect to the diameter (d) of the ballast water supply line, and the ballast water is sampled from the tip of the sampling pipe, Since the concentration of chlorinated biocide in ballast water is uniform, the amount of chlorinated biocide solution added can be determined optimally by measuring the total residual oxidizing substance concentration (TRO) in this ballast water. be able to.

In the above invention (Invention 4), it is preferable that the chemical supply device can add a neutralizing agent when discharging the ballast water (Invention 5).

According to this invention (invention 5), the amount of neutralizing agent added is optimally determined by collecting the ballast water when discharging from the sampling pipe and measuring the total residual oxidizing substance concentration (TRO). Can do.

According to the ballast water control device of the present invention, the sampling pipe is located in the ballast water supply line from the mixing portion to a position spaced three times or more on the ballast tank side with respect to the diameter (d) of the ballast water supply line. Since it is extended, ballast water can be sampled at locations where the concentration of chlorinated biocide in the ballast water is uniform. can do. Furthermore, since the chemical solution supply device and the mixing unit are close to each other, it is only necessary to construct one part of the ballast water supply line by providing a sampling pipe in the vicinity of the mixing unit.

It is the schematic which shows the control apparatus of the ballast water which concerns on one Embodiment of this invention. It is the schematic which shows the conventional ballast water control apparatus (comparative example 1).

Hereinafter, the control device and control method for ballast water of the present invention will be described in detail based on one embodiment.

FIG. 1 shows a control apparatus for ballast water according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a tubular ballast water for supplying ballast water taken from a water intake port to a ballast tank (not shown). A chemical liquid supply device 2 is connected to the ballast water supply line 1 via a chemical liquid supply line 3. In addition, a mixing unit 4 such as a static mixing device is provided so that the start end 4A is located at a connection location of the chemical solution supply line 3 in the ballast water supply line 1. On the other hand, a TRO meter 5 as a total residual oxidant concentration measuring means is connected to the end 4B side of the mixing unit 4 via a sampling pipe 6, and this sampling pipe 6 is connected to the ballast water supply line 1 in the ballast tank. Extends to the side. As a result, the chemical solution supply device 2 and the TRO meter 5 are close to each other. Reference numeral 7 denotes a chemical supply pump from the chemical supply apparatus, 8 denotes a flow rate adjusting valve, and 9 denotes a suction pump of the sampling pipe 6. In addition, as the TRO meter 5, a commercially available high-precision TRO meter using the DPD absorbance method can be used.

In this ballast water control device, the TRO meter 5 can transmit the measurement result to a control mechanism 10 such as a microcomputer, and the control mechanism 10 can control the chemical solution supply pump 7 and the flow rate based on the measured value of the TRO meter 5. The regulating valve 8 can be controlled. In the present embodiment, the control mechanism 10 is also connected to the chemical solution supply device 2, and this chemical solution supply device 2 is provided with a chlorine-based disinfectant tank 2A and a neutralizer tank 2B, and ballast water. The two tanks 2A and 2B are switched so that a chlorine-based disinfectant can be supplied from the chlorine-based disinfectant tank 2A when supplying water and a neutralizing agent can be supplied from the neutralizing tank 2B when discharging ballast water. It is possible.

In the apparatus as described above, the mixing unit 4 is not particularly limited, and a general-purpose static mixing device such as a static mixer or an orifice can be used. The terminal end of the mixing unit 4 becomes an extension starting point of a sampling pipe 6 to be described later.

Chlorine-based disinfectants stored in the chlorine-based disinfectant tank 2A include chlorinated isocyanuric acids such as hypochlorous acid (salt), dichloroisocyanurate and trichloroisocyanurate, hydrogen peroxide, and chlorine dioxide. One or two or more selected ones can be used as a solution, and hypochlorous acid (salt) is particularly preferable.

As the neutralizing agent stored in the neutralizing agent tank 2B, sodium sulfite, sodium bisulfite (sodium hydrogen sulfite), sodium thiosulfate, or the like can be used as a solution.

In this embodiment, the sampling pipe 6 extends from the end 4B of the mixing unit 4 to the ballast tank side at least 3 times the diameter (d) of the ballast water supply line 1, preferably 4 to 6 times, particularly about 5 times. Extend. When the length of the sampling pipe 6 (the position of the tip of the sampling pipe 6 from the end 4B) is less than three times the diameter (d), the chlorine-based killing agent supplied from the chemical supply device 2 is homogeneous in the ballast water. Since the concentration distribution is unevenly distributed, the measurement accuracy of the chlorine-based killing agent concentration in the ballast water is lowered, and the control of the addition amount of the chlorine-based killing agent is not suitable. The upper limit of the length of the sampling pipe 6 (the position of the tip of the sampling pipe 6 from the end 4B) is not particularly limited. However, even if the length is too long, the accuracy corresponding to the upper limit cannot be obtained. Since the installation becomes difficult, the diameter may be about 10 times the diameter (d) or less.

The diameter (d1) of the sampling pipe 6 is preferably 1/5 or less, particularly preferably 1/8 or less, of the diameter (d) of the ballast water supply line 1. By setting the ballast water supply line 1 to 1/5 or less of the diameter (d) of the ballast water supply line 1, the area of the sampling pipe 6 is sufficiently small relative to the area of the ballast water supply line 1. There is no. The lower limit of the diameter of the sampling pipe 6 may be 6A (A is the nominal diameter of the pipe JIS standard) or more from the viewpoint of water intake.

Specifically, the diameter (d) of the ballast water supply line 1 varies depending on the amount of ballast water. For example, in the case of the ballast water supply line 1 having a ballast water supply line 1 having a diameter (d) of 200 A, the diameter ( By setting d1) to 25A, the area of the sampling pipe 6 can be about 1.6% with respect to the area of the ballast water supply line 1, so that the influence on the circulation of the ballast water can be almost ignored.

In the conventional ballast water control device, the ballast water supply line 1 is provided with a separate sampling location at a position somewhat away from the chemical solution supply device 2 and the TRO meter 5 is installed in the vicinity of this sampling location. However, according to the control device for ballast water of the present embodiment as described above, since only one construction site is required, the construction range of the ballast water supply line 1 should be greatly reduced. Is economical. Specifically, in the case of a ballast water amount of 3000 m ³ / hr, the diameter (d) of the ballast water supply line 1 is 500 A, and the sampling point is separated from the diameter (d) of the ballast water supply line 1 by 5 times. In the case of the position, it is necessary to construct the 2500 mm (500 A × 5) range of the ballast water supply line 1 in the conventional apparatus, but in this embodiment, since only one place is required, the construction range itself should be reduced by about 2500 mm. Can do.

Next, a control method for ballast water when killing bacteria and plankton when the ballast water is loaded using the above-described ballast water control device will be described.

First, when the ballast water W is loaded, the taken ballast water W is supplied to a ballast tank (not shown) via the ballast water supply line 1. At this time, a sufficient amount of the chlorine-based disinfectant is stored in advance in the chlorine-based disinfectant tank 2A.

Then, the chemical solution supply pump 7 is driven, and the flow rate adjustment valve 8 is opened to add a chlorine-based killing agent to the ballast water W. The chlorine-based disinfectant is mixed and discharged from the starting end 4A to the end 4B of the mixing unit 4, but immediately after being discharged from the end 4B, the chlorine-based disinfectant is not yet sufficiently diffused and its concentration. Is unevenly distributed, and the concentration becomes uniform as it flows through the ballast water supply line 1. At least three times the diameter (d) of the ballast water supply line 1 is necessary for sufficient homogenization.

Subsequently, in this embodiment, the ballast water W is collected from the tip of the sampling pipe 6 having the diameter (d) of the ballast water supply line 1 and the total residual oxidizing substance concentration is measured by the TRO meter 5. The total residual oxidizing substance concentration is TRO (Total Residual Oxidants), and the oxidizing chlorine concentration by adding a chlorine-based killing agent and other oxidizing components generated by reaction with this oxidizing chlorine. Is included.

The TRO value measured by the TRO meter 5 is transmitted to and stored in the control mechanism 10. And based on this TRO value, when the TRO value is lower than the predetermined reference value, the addition amount of the chlorine-based killing agent is increased, and when it is higher than the predetermined reference value, the addition amount of the chlorine-based killing agent is decreased. The supply pump 7 and the flow rate adjustment valve 8 are controlled. For this control, for example, an appropriate TRO value is set on the basis of previously measured attenuation data of a chlorine-based killing agent, and a well-known PID control or the like is set so that the TRO value falls within a predetermined range. What is necessary is just to adjust the addition amount of a chlorine-type killing agent by a method.

Specifically, the addition amount of the chlorine-based killing agent is such that the total residual oxidizing substance concentration (TRO) after neutralization of the ballast water is, for example, a reference value of 0.5 to 20 mg / L (asCl ₂ ). It will be set according to the ship's schedule. If the TRO value is less than 0.5 mg / L, it will be difficult to bring harmful plank, bacteria, etc. below the reference value, or reproliferation of bacteria, etc. and hatching of plankton eggs will occur. On the other hand, even if it exceeds 20 mg / L, not only a more effective killing effect of harmful plank, bacteria, etc. is obtained, but the amount of neutralizing agent required for neutralization increases or the environment during discharge Since load increases, it is not preferable.

At this time, in this embodiment, the TRO value is accurately measured by separating the sampling pipe 6 from the terminal end 4B of the mixing unit 4 at least three times the diameter (d) of the ballast water supply line 1 as described above. Therefore, the control of the reference value of the TRO value becomes accurate, and can be maintained within ± 10% of the reference value, for example. As a result, the chlorine-based disinfectant can be added without excess or deficiency, so that plankton and bacteria in the ballast water W can be surely killed, and the ballast that meets the ballast water standard set by IMO at low cost. Water treatment can be realized.

Next, when the ballast water W is discharged, it is discharged from the ballast tank (not shown) via the ballast water supply line 1 to the external environment. At this time, a sufficient amount of neutralizing agent is stored in advance in the neutralizing agent tank 2B. Subsequently, while the chemical solution supply pump 7 is driven, the flow rate adjustment valve 8 is opened, and a neutralizing agent is added to the ballast water W to reduce the residual chlorine concentration to the target residual chlorine concentration.

At this time, in this embodiment, the ballast water W is collected from the tip of the sampling pipe 6 and the total residual oxidizing substance concentration is measured by the TRO meter 5. The TRO value measured by the TRO meter 5 is transmitted to and stored in the control mechanism 10. Based on the TRO value, the TRO value of 0.2 mg / L (asCl ₂ ) is used as a reference value. When the TRO value is higher than the reference value, the addition amount of the neutralizing agent is increased. The chemical solution supply pump 7 and the flow rate adjustment valve 8 are controlled so as to reduce the amount of addition of.

By controlling based on the TRO value in this way, the neutralizing agent can be added without excess and deficiency, and the residual chlorine concentration in the ballast water W is reduced below the target residual chlorine concentration and discharged to the external environment. be able to.

The present invention has been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the sampling pipe 6 is preferably provided along the inner wall surface of the ballast water supply line 1, but can be installed at various positions as long as it does not hinder the flow of the ballast water. Further, the total residual oxidant concentration measuring means is not limited to the measurement using a TRO meter using the DPD absorbance method, and various measuring means can be used as long as the same measurement value can be obtained. Is applicable.

The following specific examples further illustrate the present invention.
[Example 1]
In the apparatus shown in FIG. 1, the diameter (d) 200A of the ballast water supply line 1, the diameter (d1) 20A of the sampling pipe 6, and an orifice as the mixing unit 4 are 1000 mm (≈5 × (d) from the end of the orifice. The ballast water W was filled in the ballast tank using a device in which the sampling pipe 6 was extended on the ballast tank side. At this time, the control mechanism 10 controlled the ballast W so that the measured value of the TRO meter 5 was 15.0 mg / L (asCl ₂ ). Table 1 shows the maximum value, minimum value, average value, and maximum error (| maximum value or minimum value−average value | / average value × 100) (%) of the measured values of the TRO meter 5 during this period.

[Comparative Example 1]
As shown in FIG. 2, the ballast water W is ballasted using a device in which the sampling unit 6A and the TRO meter 5 are installed at a position of 1000 mm (≈5 × (d)) with a diameter (d) 200A of the ballast water supply line 1. Filled the tank. At this time, the control mechanism 10 controlled the ballast W so that the measured value of the TRO meter 5 was 15.0 mg / L (asCl ₂ ). Table 1 shows the maximum value, minimum value, average value, and maximum error (| maximum value or minimum value−average value | / average value × 100) (%) of the measured values of the TRO meter 5 during this period.

[Comparative Example 2]
In Example 1, the ballast water is sampled from the connection point of the sampling pipe 6 to the ballast water supply line 1 (the terminal end 4B of the mixing unit 4), and the measured value of the TRO meter 5 is similarly 15.0 mg / L ( asCl ₂ ). Table 1 shows the maximum value, minimum value, average value, and maximum error (| maximum value or minimum value−average value | / average value × 100) (%) of the measured values of the TRO meter 5 during this period.

As is apparent from Table 1, in the ballast water control device of Example 1, the maximum error is equal to or less than that of Comparative Example 1 as a conventional example, and the average value of TRO meter 5 is 15.0 mg / L (asCl ₂ ) or more, and within ± 10% of the set value, it can be seen that control can be performed reliably. On the other hand, in Comparative Example 2 in which the ballast water was sampled at the terminal portion 4B of the mixing unit 4, the maximum error was 100% or more, and the average value also deviated significantly from 15.0 mg / L-Cl ₂ . It turns out that it is not controlled.

With the ballast water control device of the present invention, it is possible to optimally determine the addition amount of the chlorine-based killing agent by constructing only one place of the ballast water supply line. Economic efficiency improves, and as a result, the spread of the ballast water control device becomes easy.

DESCRIPTION OF SYMBOLS 1 ... Ballast water supply line 2 ... Chemical liquid supply apparatus 2A ... Chlorine-type killing agent tank 2B ... Neutralizer tank 3 ... Chemical liquid supply line 4 ... Mixing part 4A ... Start end 4B ... End 5 ... TRO meter (total residual oxidizing substance) Concentration measuring means)
6 ... Sampling pipe 7 ... Chemical supply pump 8 ... Flow rate adjusting valve 9 ... Suction pump 10 ... Control mechanism W ... Ballast water d ... Ballast water supply line diameter d1 ... Sampling pipe diameter

Claims (5)

1. A ballast water supply line for supplying the taken ballast water to the ballast tank, and a chemical solution supply device for supplying a chlorinated biocide solution for killing aquatic microorganisms in the ballast water to the ballast water supply line And a ballast water treatment system comprising a mixing part of the chlorine-based disinfectant solution provided in the ballast water supply line,
   A sampling pipe is installed in the ballast water supply line so as to extend from the mixing section to a position at least three times the ballast tank side with respect to the diameter (d) of the ballast water supply line, and connected to the sampling pipe. To provide a means for measuring the total residual oxidizing substance concentration
   A control device for controlling ballast water, comprising a control mechanism for controlling the chemical solution supply device based on a measurement result of the total residual oxidant concentration measuring means.
2. The ballast water control device according to claim 1, wherein a diameter (d1) of the sampling pipe is 1/5 or less of a diameter (d) of the ballast water supply line.
3. 3. The ballast water control device according to claim 1, wherein the chemical solution supply device can add a neutralizing agent when discharging the ballast water.
4. A chlorine-based disinfectant solution for killing aquatic microorganisms in the ballast water is supplied from a chemical supply device to the ballast water supply line that supplies the taken ballast water to the ballast tank, and the ballast water supply line enters the ballast water supply line. A control method of a ballast water treatment system for mixing in a provided mixing unit,
   The ballast water is collected from the tip of a sampling pipe that extends from the mixing section to a position spaced three times or more on the ballast tank side with respect to the diameter (d) of the ballast water supply line in the ballast water supply line,
   The total residual oxidizing substance concentration (TRO) of the collected ballast water is measured by a total residual oxidizing substance concentration measuring means provided in the vicinity of the mixing unit,
   A control method for a ballast water treatment system, wherein a supply amount of the chlorine-based disinfectant solution is controlled based on a measurement result of the total residual oxidizing substance concentration measuring means.
5. The method for controlling a ballast water treatment system according to claim 4, wherein the chemical solution supply device can add a neutralizing agent when discharging the ballast water.

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