SYSTEM FOR TREATING SHIPS' BALLAST WATER

Abstract

The system for treating ships' ballast water, which is attached to a ship that sails a sea route having a plurality of calling ports, comprises: a disinfectant reservoir that stores a disinfectant; a data acquisition means that acquires stored disinfectant information regarding a remaining amount and an effective chlorine concentration of a disinfectant stored in the disinfectant reservoir; a data storage means that stores supplier information regarding a disinfectant supplier at each of the plurality of calling ports and sea route information regarding a call sequence and a call schedule for the plurality of calling ports; and a data calculation means that determines whether or not an order for the disinfectant has to be placed, on the basis of the stored disinfectant information.

Claims

1. A system for treating ships' ballast water, the system being attached to a ship that sails a sea route having a plurality of calling ports, the system comprising: a disinfectant reservoir that stores a disinfectant; a data acquisition means that acquires stored disinfectant information regarding a remaining amount and an effective chlorine concentration of a disinfectant stored in the disinfectant reservoir; a data storage means that stores supplier information regarding a disinfectant supplier at each of the plurality of calling ports and sea route information regarding a call sequence and a call schedule for the plurality of calling ports; and a data calculation means that determines whether or not an order for the disinfectant has to be placed, on a basis of the stored disinfectant information, wherein when determining that the order for the disinfectant has to be placed, the data calculation means makes a determination as to which calling port among the plurality of calling ports at which the order for the disinfectant is placed with a disinfectant supplier.

2. The system for treating ships' ballast water according to claim 1, wherein the disinfectant is sodium hypochlorite.

3. The system for treating ships' ballast water according to claim 1, wherein the supplier information includes information regarding a lead time required for delivering a disinfectant that is not deteriorated to the ship from when a disinfectant supplier at each of the plurality of calling ports accepts the order.

4. The system for treating ships' ballast water according to claim 1, further comprising a data communication means that places the order for the disinfectant with the disinfectant supplier determined by the data calculation means.

5. The system for treating ships' ballast water according to claim 4, wherein the data communication means automatically places the order for the disinfectant in response to the determination of the disinfectant supplier made by the data calculation means.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0021] FIG. 1 is an explanatory diagram illustrating the configuration of a system for treating ships' ballast water according to an embodiment of the present invention.

[0022] FIG. 2 is an explanatory diagram illustrating the configuration of a data processing device in the treatment system.

[0023] FIG. 3 is an explanatory diagram illustrating the calling ports and sea route for a ship equipped with the treatment system.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0024] Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. As illustrated in FIG. 1, the system for treating ships' ballast water 1 according to the present embodiment may include a water intake part 11 for raw water W as ballast water, a main line 12 that is connected to the water intake part 11 and feeds the raw water W, and a ballast tank 13 provided at the end of the main line 12. A liquid feed pump 14 as a means for feeding the raw water W may be provided just downstream the position at which the water intake part 11 is connected to the main line 12. The main line 12 branches to a discharge line 15 at the midstream of the main line 12 (before the ballast tank 13), and the end of the discharge line 15 serves as a drainage part 16. The branch point from the main line 12 to the discharge line 15 may be provided with an on-off valve (not illustrated) that switches between the main line 12 and the discharge line 15.

[0025] The midstream of the main line 12 may be provided with a disinfectant supply line that includes a disinfectant reservoir 21 and a liquid feed pump 22. The disinfectant supply line is configured to be able to inject the disinfectant into the raw water W flowing in the main line 12. The midstream of the discharge line 15 may be provided with a neutralizer solution supply line that includes a neutralizer solution reservoir 31. The neutralizer solution supply line is configured to be able to inject the neutralizer solution into the discharged water (discharged ballast water) from the ballast tank 13 flowing in the discharge line 15.

[0026] On the main line 12, a first flow meter 41 may be provided on the downstream side of the liquid feed pump 14 and on the upstream side of the connection part with the disinfectant supply line. The first flow meter 41 measures the flow rate of the raw water W flowing through the main line 12. On the disinfectant supply line, a second flow meter 42 may be provided on the downstream side of the liquid feed pump 22. The second flow meter 42 measures the flow rate of the disinfectant injected into the main line 12. On the main line 12, a first chlorine concentration meter 43 may be provided on the downstream side of the connection part with the disinfectant supply line. The first chlorine concentration meter 43 measures the concentration of chlorine in the ballast water (which is obtained by injecting the disinfectant into the raw water W). On the discharge line 15, a second chlorine concentration meter 44 may be provided on the downstream side of the connection part with the neutralizer solution supply line. The second chlorine concentration meter 44 measures the concentration of chlorine in the discharged ballast water.

[0027] In the present embodiment, sodium hypochlorite may be used as the disinfectant while sodium sulfite or sodium bisulfite may be used as the neutralizer. The treatment system 1 of the present embodiment may not necessarily be used only with these disinfectant and neutralizer, but may preferably be used particularly when the disinfectant is sodium hypochlorite.

[0028] The disinfectant reservoir 21 may have a temperature management function achieved by a water-cooling chiller, an air-cooling chiller, or the like and store and manage the disinfectant in a state in which the temperature is controlled, thereby to suppress the phenomenon that the disinfectant deteriorates due to high temperatures on the ship.

[0029] As will be understood, the disinfectant reservoir 21 may have a size that allows for storage of the disinfectant with which the ballast water can be treated once, but may preferably have a capacity enough to treat the ballast water at least twice and more preferably three times. When the disinfectant reservoir 21 has such a capacity, the necessary amount of effective chlorine can be injected into the volume of the ship's ballast water even if the disinfectant deteriorates during storage. A level meter 45 may be installed in the disinfectant reservoir 21 and can measure the remaining amount of the disinfectant in the disinfectant reservoir 21.

[0030] A data processing device 50 may be provided in the ship S equipped with the treatment system 1 according to the present embodiment. The data processing device 50 may be, for example, a general-purpose personal computer or the like installed in the bridge, wheelhouse, engine room, or the like of the ship S. As illustrated in FIG. 2, the data processing device 50 may include a data calculation unit 51, a data storage unit 52, and a data communication unit 53. The data processing device 50 is connected to four meters so as to be capable of electrical communication with each other. The four meters comprise: the first flow meter 41 which measures the flow rate of the raw water W flowing through the main line 12; the second flow meter 42 which measures the flow rate of the disinfectant added into the main line 12; the first chlorine concentration meter 43 which measures the concentration of chlorine in the ballast water; and the level meter 45 which measures the remaining amount of the disinfectant in the disinfectant reservoir 21. The data processing device 50 is configured to be able to receive the measured value data acquired by each meter from the meter.

[0031] The data calculation unit 51 serves to acquire stored disinfectant information regarding the remaining amount and effective chlorine concentration of the disinfectant stored in the disinfectant reservoir 21 and determines whether or not an order for the disinfectant has to be placed, on the basis of the stored disinfectant information. When determining that the order for the disinfectant has to be placed, the data calculation unit 51 makes a determination as to which calling port among a plurality of calling ports at which the order for the disinfectant is placed with a disinfectant supplier, on the basis of supplier information and sea route information, which will be described later.

[0032] The stored disinfectant information may include information regarding the remaining amount of the disinfectant in the disinfectant reservoir 21, which is received from the level meter 45, and information regarding the effective chlorine concentration of the disinfectant in the disinfectant reservoir 21, which is estimated from the concentration of chlorine in the ballast water received from the first chlorine concentration meter 43.

[0033] In the present embodiment, the effective chlorine concentration of the disinfectant in the disinfectant reservoir 21 may be estimated as follows. The ballast water treatment may be carried out so that the concentration of chlorine in the ballast water measured by the first chlorine concentration meter 43 becomes a prescribed chlorine concentration T (mg/L as Cl.sub.2). In this operation, the relationship of T=1000c*s/b is established using a ballast water flow rate b (m.sup.3/h) measure by the first flow meter 41, a disinfectant flow rate s (m.sup.3/h) measured by the second flow meter 42, and an effective chlorine concentration c (g/L) of the disinfectant in the disinfectant reservoir 21. However, considering that the concentration of chlorine in the ballast water decreases by about 20% due to the early decrease until the concentration of chlorine is measured by the first chlorine concentration meter 43 from when the disinfectant is injected, the above relationship may be modified to 1.2*T=1000c*s/b, and the effective chlorine concentration of the disinfectant in the disinfectant reservoir 21 can be obtained using an equation of c=1.2 Tb/1000 s.

[0034] The data storage unit 52 may preliminarily store the supplier information and the sea route information. The supplier information, which is information regarding a disinfectant supplier at each of a plurality of calling ports for the ship S, may include information regarding a lead time required for delivering a disinfectant that is not deteriorated to the ship from when a disinfectant supplier at each of the plurality of calling ports for the ship S accepts the order. The sea route information is information regarding a call sequence and a call schedule for the plurality of calling ports for the ship S.

[0035] Specifically, as illustrated in FIG. 3 for example, when cargos are loaded and unloaded for the ship S at a plurality of calling ports P1, P2, P3, P4, P5, and P6, the data storage unit 52 may store the sea route information, such as information on the schedule that the ship S sails in the order of P1-P2-P3-P4-P5-P6, the scheduled date of arrival at each calling port, the number of days required for loading and unloading the cargos, and the scheduled date of departure from each calling port. The data storage unit 52 may also store the supplier information, such as information on a disinfectant supplier at each calling port and the lead time required for delivering a disinfectant that is not deteriorated to the ship from when each disinfectant supplier accepts the order.

[0036] When the data calculation unit 51 determines that an order for the disinfectant has to be placed and makes a determination as to which calling port among the plurality of calling ports P1, P2, P3, P4, P5, and P6 at which the order for the disinfectant is placed with a disinfectant supplier, the data communication unit 53 may transmit the ordering data to order the disinfectant to the supplier with which the order is determined to be placed. The transmission of the ordering data may be carried out, for example, by sending an e-mail, sending data in an on-line system dedicated to placing the order online, sending a facsimile, or the like or by using other communication means. In addition or alternatively, the system may be configured such that the order for the disinfectant is automatically placed in response to the determination of the supplier made by the data calculation unit 51, and it is thereby possible to promptly convey the determination of the order to the supplier and more steadily receive the delivery of a disinfectant having deteriorated as little as possible.

[0037] A processing flow leading up to receiving the delivery of a disinfectant having deteriorated as little as possible will be described. This flow may be executed by the treatment system 1 having the configuration as described above. First, after the ballast water treatment is carried out at a calling port, the level meter 45 measures a remaining amount V (m.sup.3) of the disinfectant in the disinfectant reservoir 21, and the data calculation unit 51 acquires the measured value. The first chlorine concentration meter 43 measures a chlorine concentration T (mg/L as Cl.sub.2) of the ballast water, which may be used together with the ballast water flow rate b (m.sup.3/h) measured by the first flow meter 41 and the disinfectant flow rate s (m.sup.3/h) measured by the second flow meter 42, thereby to estimate the effective chlorine concentration c (g/L) of the disinfectant in the disinfectant reservoir 21, and the data calculation unit 51 acquires the estimated value.

[0038] For the ballast water treatment at the next calling port, the amount of disinfectant V.sub.0 (m.sup.3) necessary for the ballast water B (m.sup.3) as an object of the treatment to have a prescribed concentration T (mg/L as Cl.sub.2) may be obtained in accordance with V.sub.0=1.2BT/1000c on the basis of the relational expression 1.2T=1000c*V.sub.0/B which is modified from the relational expression T=1000c*V.sub.0/B obtained with consideration for the decrease of 20% due to the early decrease of the concentration of chlorine in the ballast water.

[0039] The data calculation unit 51 may compare the remaining amount V (m.sup.3) of the disinfectant in the disinfectant reservoir 21 with the necessary amount of disinfectant V.sub.0 (m.sup.3) and determine that an order for the disinfectant has to be placed, for example, upon V<2V.sub.0.

[0040] When determining that the order for the disinfectant has to be placed, the data calculation unit 51 may make a determination as to which calling port at which the order for the disinfectant is placed with a disinfectant supplier, on the basis of the sea route information and supplier information stored in the data storage unit 52. For example, provided that the required time from the current location to the first calling port P1 is T1, the lead time required at P1 is L1, the required time from the calling port P1 to the second calling port P2 is T2, and the lead time required at P2 is L2, when T1L1 is satisfied, delivery at the first calling port P1 can be ordered thereby to allow the delivery of the disinfectant, which is not deteriorated, to be received.

[0041] In the case of T1<L1 and T1+T2L2, when V.sub.0<V<2V.sub.0 is satisfied, delivery at the first calling port P1 may not be ordered and delivery at the second calling port P2 may be ordered. After the cargos are unloaded at the first calling port P1, V<V.sub.0 holds, but no particular problem occurs because the delivery of a disinfectant that is not deteriorated can be received at the second calling port P2.

[0042] Likewise, in the case of T1<L1 and T1+T2L2, if V<V.sub.0 holds, this causes a shortage of the disinfectant used when treating the ballast water at the first calling point P1. In such a case, therefore, delivery of the disinfectant for compensating for the shortage in the ballast water treatment at the first calling port P1 may be ordered, and delivery at the second calling port P2 may also be ordered. In this case, the lead time required for delivering a disinfectant that is not deteriorated may be insufficient because of T1<L1 at the calling port P1, so that a disinfectant that is deteriorated to some extent will be delivered, but at the second calling port P2, delivery of a disinfectant that is not deteriorated can be received. Placing the order in this way makes it possible to minimize the amount of the delivered disinfectant which is deteriorated to some extent. As will be understood, in such a case, it may be difficult to avoid the delivery of a disinfectant that is deteriorated to some extent at the calling port P1, and it is thus preferred to execute the control so that such situations take place as little as possible.

[0043] When the data calculation unit 51 determines that an order for the disinfectant has to be placed and makes a determination as to which calling port among the plurality of calling ports P1, P2, P3, P4, P5, and P6 at which the order for the disinfectant is placed with a disinfectant supplier, the data communication unit 53 may automatically transmit the ordering data to order the disinfectant to the supplier with which the order is determined to be placed. Through this operation, the supplier can be determined such that the disinfectant is delivered at appropriate timing at a calling port suitable for delivery, and the determination can be promptly conveyed to the supplier. It is thus possible to more steadily receive the delivery of a disinfectant having deteriorated as little as possible. In usual cases, the amount of order may be the difference between the remaining amount V of the disinfectant in the disinfectant reservoir 21 and the tank capacity of the disinfectant reservoir 21.

[0044] According to such a treatment system 1, necessity of placing an order for the disinfectant is determined on the basis of the stored disinfectant information regarding the remaining amount and effective chlorine concentration of the disinfectant in the disinfectant reservoir 21. When placing an order for the disinfectant is necessary, the supplier can be determined on the basis of the supplier information and the sea route information, which are preliminarily stored in the data communication unit 53, so that the disinfectant is delivered at appropriate timing at a calling port suitable for delivery. It is thus possible to receive the delivery of a disinfectant having deteriorated as little as possible.

[0045] In particular, information on the lead time required for delivering a disinfectant that is not deteriorated to the ship S from when a disinfectant supplier at each of the plurality of calling ports for the ship S accepts the order may be included as one item of the supplier information which is preliminarily stored in the data communication unit 53, and the delivery of a disinfectant having deteriorated as little as possible can thereby be received at more appropriate timing. It is thus possible to reduce the risk that the expense burden increases due to the extension of staying time at the port and the extra labor and expense are needed to treat or discard the unused disinfectant.

[0046] The embodiments heretofore explained are described to facilitate understanding of the present invention and are not described to limit the present invention. It is therefore intended that the elements disclosed in the above embodiments include all design changes and equivalents to fall within the technical scope of the present invention.

[0047] For example, in the present embodiment, the effective chlorine concentration of the disinfectant in the disinfectant reservoir 21 is estimated from the concentration of chlorine in the ballast water received from the first chlorine concentration meter 43, but the effective chlorine concentration of the disinfectant in the disinfectant reservoir 21 may also be directly measured.

[0048] In the present embodiment, one data processing device 50 is configured to achieve each of functions of the data acquisition means, the data calculation means, the data storage means, and the data communication means, but the system may also be configured such that multiple devices are used to separately achieve each of functions of the data acquisition means, the data calculation means, the data storage means, and the data communication means.

[0049] In addition or alternatively, the system may be configured such that, when the data calculation unit 51 of the data processing device 50 cannot determine or select a disinfectant supplier due to the time limit for placing an order or the like, a warning against this fact is given to the crew members through an audio output device (not illustrated) and/or a display device (not illustrated) such as a liquid-crystal monitor, so that a crew member who receives the warning can manually place an order for the disinfectant with an optimum supplier.

DESCRIPTION OF REFERENCE NUMERALS

[0050] 1 System for treating ships' ballast water [0051] 11 Water intake part [0052] 12 Main line [0053] 13 Ballast tank [0054] 14 Liquid feed pump [0055] 15 Discharge line [0056] 16 Drainage part [0057] 21 Disinfectant reservoir [0058] 22 Liquid feed pump [0059] 31 Neutralizer solution reservoir [0060] 41 First flow meter [0061] 42 Second flow meter [0062] 43 First chlorine concentration meter [0063] 44 Second chlorine concentration meter [0064] 50 Level meter [0065] 50 Data processing device [0066] 51 Data calculation unit [0067] 52 Data storage unit [0068] 53 Data communication unit