JP7234684B2 - Ballast water treatment system - Google Patents

Description

The present invention relates to a liquid treatment apparatus with a filter.

A ship such as a tanker normally stores water called ballast water in a ballast tank in order to balance the ship during navigation when it sails toward its destination after unloading cargo such as crude oil. Such ships are equipped with a water treatment device (ballast water treatment device) that purifies ballast water in order to prevent the ecosystem from being destroyed by the injection and discharge of ballast water.

As one type of ballast water treatment apparatus, a system (filtration apparatus) that filters ballast water by arranging a cylindrical filter in a casing is known. In this method, constant cleaning of the filter is considered important in order to prevent clogging of the filter.

Therefore, as a configuration for removing foreign matter deposited on a filter, for example, Patent Document 1 describes a configuration in which a cleaning nozzle is disposed on the secondary side of the filter and ejects cleaning water toward the filter. there is

JP 2004-141785 A

By the way, in a filtering device equipped with such a cleaning nozzle, jetting of cleaning water is controlled based on the differential pressure across the filter. However, when the flow rate of the liquid such as water flowing through the filter is low, there is a problem that even if the filter clogging progresses, the differential pressure for jetting the cleaning liquid is not reached, so cleaning is not performed. In addition, if the flow rate is increased in such a state, the differential pressure increases, which may adversely affect the filter or the like.

Furthermore, not only the control of jetting of wash water, but also the flow rate of liquid such as water flowing through the filter and the operation of the control target such as the ballast water treatment system itself can be controlled based on the differential pressure across the filter. Conceivable. However, even in this case, if the flow rate of liquid such as water is small, the differential pressure does not increase, so it is difficult to perform appropriate control.

The present invention has been made in view of such circumstances. It is an object of the present invention to provide a controllable liquid treatment apparatus.

According to the present invention, a liquid treatment apparatus comprising a filter, comprising a pressure sensor, a flow meter and control means, said pressure sensor being arranged to detect primary and secondary pressures of said filter. and the flow meter is configured to detect the flow rate of the liquid filtered by the filter, and the control means measures the differential pressure between the primary pressure and the secondary pressure detected by the pressure sensor as the flow rate A liquid treatment apparatus is provided that controls a control target by comparing with a threshold set based on the flow rate of liquid detected by a meter.

According to the present invention, the control means controls the cleaning liquid ejection means based on the differential pressure between the primary pressure and the secondary pressure of the filter and the flow rate of the liquid flowing through the filter, so that the flow rate of the liquid flowing through the filter changes. It is possible to properly clean the filter even when

Various embodiments of the present invention are illustrated below. The embodiments shown below can be combined with each other.

Preferably, the controlled object is at least one of the following (1) to (3).
(1) Operation of cleaning liquid jetting means configured to jet cleaning liquid toward the filter (2) Flow rate of liquid filtered by the filter (3) Operation of the liquid processing apparatus

Preferably, the control means sets the threshold by calculation on a case-by-case basis or based on a pre-stored table.

Preferably, the filter comprises a discharge means and a rotation means, the filter being cylindrically formed, the discharge means comprising a discharge nozzle and a discharge pipe, the discharge nozzle being located on the primary side of the filter. The discharge pipe is arranged to discharge water introduced from the discharge nozzle to the outside of the liquid treatment device, and the rotating means is configured to rotate the filter.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structure of the ballast water treatment apparatus 100 which concerns on embodiment of this invention.

Embodiments of the present invention will be described below. Various features shown in the embodiments shown below can be combined with each other. In addition, the invention is established independently for each feature.

A ballast water treatment apparatus 100 as a liquid treatment apparatus according to an embodiment of the present invention is installed in a ballast apparatus installed on a ship for purification of ballast water. It should be noted that the "ballast water" in this specification is introduced (flowed) into the ballast water treatment apparatus 100, regardless of whether it is before being introduced into a ballast tank (not shown) or after being discharged from the ballast tank. Regardless of whether it is before or after being discharged (outflowed) from the ballast water treatment device 100, all water taken into the ship is referred to as "ballast water." In addition, the ballast water taken into the ship shall include sea water, fresh water, brackish water, etc.

1. Configuration A ballast water treatment apparatus 100 of the present embodiment includes a cylindrical casing 1, a cylindrical filter 2, and filter rotating means 3, as shown in FIG. The cylindrical filter 2 is arranged in the casing 1 and filters unfiltered ballast water such as seawater that has flowed into the interior (primary side) and allows it to flow out to the outside (secondary side). The filter rotating means 3 rotates the filter 2 around its axis.

Further, the ballast water treatment apparatus 100 includes a discharge means 4 for discharging ballast water on the primary side of the filter 2 and a discharge means 4 for discharging the ballast water on the primary side of the filter 2 for cleaning the filter 2 during the filtration process. a cleaning liquid ejecting means 5 for ejecting cleaning water, a pressure sensor 6 for detecting the pressure on the primary side (primary pressure) and the pressure on the secondary side (secondary pressure) of the filter 2, and a control means 7; Each configuration will be specifically described below.

The casing 1 is formed in a cylindrical shape, and has an upper opening sealed with a lid 11 and a lower opening sealed with a bottom 12 . The cylindrical filter 2 placed in the casing 1 has its upper opening sealed with an upper closing part 13 and its lower opening closed with a lower closing part 14 . These configurations separate the interior of the filter 2 (primary side) from the space between the casing 1 and the filter 2 (secondary side). The filter 2 is formed, for example, by bending a metal plate in which a large number of through holes are formed into a cylindrical shape and welding a pair of side edge portions extending in the axial direction of the cylindrical shape.

An inlet 15 for introducing ballast water before filtration into the filter 2 is provided in the lower portion of the casing 1 . An introduction line L<b>1 is connected to the introduction port 15 . The introduction line L1 is connected to a pump 8 of a ballast device that pumps the ballast water through the on-off valve V1. Further, an outflow port 16 is provided in the side portion of the casing 1 through which ballast water that has passed through the filter 2 and has been subjected to filtering treatment flows out.

Ballast water introduced from the introduction port 15 through the introduction line L1 enters the filter 2 through the lower rotating shaft member 32, passes through the filter 2, is filtered, and is formed between the casing 1 and the filter 2. It enters the space and exits through the outlet 16 . The filtered ballast water flowing out from the outflow port 16 flows through the outflow line L2 and is stored in a ballast tank (not shown).

An on-off valve V2 and a flow meter 9 are provided in the outflow line L2. The flow meter 9 detects the flow rate of ballast water that flows through the ballast water treatment device 100 (filter 2) and is treated. It is also preferable to arrange other purification means such as an ultraviolet treatment device (not shown) that kills organisms with ultraviolet rays on the outflow line L2.

The filter rotating means 3 includes an upper rotating shaft member 31 , a lower rotating shaft member 32 and a motor 33 . The upper rotating shaft member 31 holds the upper closing portion 13 of the filter 2 and the lower rotating shaft member 32 holds the lower closing portion 14 . The motor 33 rotates the upper rotating shaft member 31 . The upper rotating shaft member 31 passes through the lid portion 11 of the casing 1 and is rotatably and liquid-tightly supported by the lid portion 11 via a sealed bearing member 18 . The lower rotary shaft member 32 passes through the bottom portion 12 of the casing 1 and is rotatably and liquid-tightly supported on the bottom portion 12 via a sealed bearing member 19 . The lower rotating shaft member 32 is a tubular body that communicates with the inside of the filter 2 and protrudes from the bottom portion 12 of the casing 1 to the outside of the casing 1 .

The discharge means 4 includes a plurality of discharge nozzles 41 and discharge pipes 42 . The discharging means 4 is used to discharge foreign matter adhering to the filter 2 to the outside of the casing 1 .

The discharge nozzle 41 has a slit-like opening at its tip toward the inner peripheral surface (primary side surface) of the filter 2 and is arranged to face the filter 2 . A proximal end of the discharge nozzle 41 is connected to the discharge pipe 42 . In this embodiment, the discharge nozzles 41 are provided in four rows at intervals of 90 degrees in the circumferential direction, three in each row in the vertical direction, for a total of 12 nozzles (in FIG. 1, nozzles other than those extending rightward are omitted). . In order to eliminate unsucked portions between the discharge nozzles 41 arranged vertically, the height direction of each row is adjusted so that the discharge nozzles 41 of another row are positioned between the discharge nozzles 41 of one row. are staggered.

The discharge pipe 42 is arranged inside the filter 2 on the upper side and extends to the outside of the casing 1 on the lower side. More specifically, the upper portion of the discharge pipe 42 is arranged at a position coinciding with the central axis of the filter 2, and has a closed upper end and an open lower end. The upper end of the discharge pipe 42 is inserted into and supported by a hole provided in the center of the upper rotating shaft member 31 of the filter 2 . The lower part of the discharge pipe extends downward inside the lower rotating shaft member 32 so as not to hinder the rotation of the filter 2 . The lower end side of the discharge pipe 42 is bent and extended, and penetrates the peripheral surface of the introduction port 15 . The ballast water and the foreign matter that have passed through the discharge nozzle 41 flow together in the discharge pipe 42, and are discharged to the outside of the casing 1 (ballast water treatment apparatus 100). Further, the discharge pipe 42 of the present embodiment is provided with a control valve (not shown) whose opening can be adjusted.

The cleaning liquid ejecting means 5 includes a plurality of cleaning nozzles 51 , a cleaning line 52 and a cleaning pump 53 . A plurality of cleaning nozzles 51 are provided on the side portion of the casing 1 , and the tip portions open toward the inside of the casing, particularly toward the outer peripheral surface of the filter 2 . In this embodiment, each cleaning nozzle 51 is arranged on the same circumference as each discharge nozzle 41 arranged in plurality. It is preferable that each cleaning nozzle 51 can jet the cleaning liquid over the entire area of the filter 2 in the axial direction, but the configuration is not particularly limited.

The cleaning line 52 is connected to each cleaning nozzle 51 and supplies the cleaning liquid pressure-fed by the cleaning pump 53 to each cleaning nozzle 51 . The cleaning line 52 is also provided with an on-off valve 54 . The upstream side of cleaning line 52 is connected to a cleaning fluid supply (not shown). Ballast water treated with the filter 2 can be used as the cleaning liquid. However, the water stored in the ballast tank, or domestic water or drinking water stored for other purposes may also be used.

The pressure sensor 6 includes a primary side sensor 61 and a secondary side sensor 62 . The primary side sensor 61 is arranged on the primary side of the filter 2 and detects the primary pressure P1 of the filter 2 . The secondary side sensor 62 is arranged on the secondary side of the filter 2 and detects the secondary pressure P2 of the filter 2 . In addition, specific positions of the “primary side of the filter 2” include, for example, the inside of the filter 2, the inside of the introduction port 15, and the top of the introduction line L1. However, it is not limited to these positions. Further, as a specific position of the "secondary side of the filter 2", for example, the space between the casing 1 and the filter 2 (including the one where the socket is installed in the casing 1), the inside of the outflow port 16, and the outflow On line L2 can be mentioned. However, it is not limited to these positions.

The control means 7 detects the primary pressure P1 of the filter 2 detected by the primary sensor 61 and the secondary pressure P2 of the filter 2 detected by the secondary sensor 62, and calculates the differential pressure between the primary pressure P1 and the secondary pressure P2. ΔP (=P1−P2) is derived. The degree of contamination of the filter 2 can be determined from this differential pressure ΔP. That is, when the differential pressure ΔP is large, it indicates that the amount of foreign matter deposited on the filter 2 is large, and when the differential pressure is small, it indicates that the filter 2 is in a state close to the initial state.

Further, the control means 7 acquires the flow rate Q of the circulating ballast water from the flow meter 9 installed in the outflow line L2. Then, the control means 7 controls the operation of the cleaning liquid jetting means 5 based on the differential pressure ΔP and the flow rate Q. As shown in FIG. Concrete control of the cleaning liquid ejection means 5 by the control means 7 will be described later.

2. Operation Next, the operation of the ballast water treatment device 100 of the present embodiment, particularly the operation of cleaning the filter 2 during the filtration process will be described.

When the ballast water flows through the inlet 15 through the inlet line L1 by driving the pump 8, the ballast water enters the filter 2, passes through the filter 2, and is filtered. At this time, the filter rotating means 3 rotates the filter 2 . As a result, the filter 2 rotates relative to the discharge means 4 . The ballast water then enters the space formed between the casing 1 and the filter 2 and flows out from the outlet 16 . The outflowing ballast water passes through the outflow line L2 and is stored in a ballast tank (not shown).

The cleaning operation during the ballast water filtration process is performed continuously or intermittently during the filtration process. Specifically, since the pressure in the discharge means 4 is lower than the secondary pressure of the filter 2, by opening the regulating valve installed in the discharge pipe 42, the foreign matter adhering to the filter 2 is removed from the filter 2. Together with the filtered ballast water on the next side, the ballast water is sucked from the opening of the discharge nozzle 41 and discharged to the outside through the discharge pipe 42 .

Further, during cleaning during the filtration process, the control means 7 opens the on-off valve 54 of the cleaning liquid jetting means 5 and drives the cleaning pump 53 to jet the cleaning liquid from each cleaning nozzle 51 toward the filter 2 . . When the cleaning liquid is jetted, the foreign matter deposited on the primary side of the filter 2 is removed, and immediately after the separation, the discharge nozzle 41 sucks the foreign matter. be.

Here, the control means 7 controls the operation of the cleaning liquid jetting means 5 by comparing the differential pressure ΔP with a predetermined threshold value Pq. The threshold value Pq is stored in a storage section (not shown) of the control means 7 . Specifically, when the differential pressure ΔP is equal to or less than the threshold value Pq, the control means 7 determines that the amount of foreign matter deposited on the filter 2 is small, and stops the operation of the cleaning liquid jetting means 5 . On the other hand, when the differential pressure ΔP is greater than the threshold value Pq, the control means 7 determines that the amount of foreign matter deposited on the filter 2 has increased, and operates the cleaning liquid jetting means 5 to start cleaning. In the present embodiment, "the operation of the cleaning liquid ejecting means 5" is controlled by the control means 7. FIG.

In this embodiment, the control means 7 changes the threshold value Pq of the differential pressure ΔP based on the flow rate Q of the circulating ballast water detected by the flow meter 9 (according to the flow rate Q). Specifically, when the flow rate Q of the ballast water is small, the control means 7 sets the threshold value Pq to be small, and operates the cleaning liquid jetting means 5 even if the differential pressure ΔP is small. On the other hand, when the flow rate Q of the ballast water is the rated treatment flow rate, the threshold value Pq is raised more than when the flow rate Q is small, and the washing liquid jetting means 5 is not operated until the differential pressure ΔP becomes large. In addition, when the flow rate Q of the ballast water becomes equal to or higher than the rated treatment flow rate, the threshold value Pq may be maintained, or the threshold value Pq may be set larger.

A more specific example of how the control means 7 changes the threshold value Pq based on the flow rate Q of the circulating ballast water is as follows. Assuming that the rated flow rate of the ballast water treatment device 100 is Qr, the control means 7 sets the threshold value Pq to the first threshold value Pq1 when the flow rate Q is less than Qr/3 (Q<Qr/3), and the flow rate Q is Qr /3 or more and less than Qr/2 (Qr/3<Q<Qr/2), the threshold Pq is set to a second threshold Pq2 (>Pq1) larger than the first threshold Pq1, and the flow rate Q is Qr/2 or more. If (Qr/2<Q), the threshold Pq is set to a third threshold Pq3 (>Pq2) that is greater than the second threshold Pq2. If an ultraviolet reactor (not shown) is installed in the outflow line L2, the rated flow rate of the ultraviolet reactor may be used instead of the rated flow rate of the ballast water treatment device 100 to define the reference flow rate.

In this way, the control means 7 stores a plurality of threshold values Pq (for example, the first threshold value Pq1 to the third threshold value Pq3) according to the flow rate Q as a table, and sets the threshold value Pq based on the table. It's becoming In addition to the threshold value Pq, it is also possible to perform control to adjust the ejection pressure of the cleaning liquid according to the flow rate Q.

As another example of changing the threshold value Pq of the differential pressure ΔP based on the flow rate Q of the circulating ballast water by the control means 7, the following calculation formula (i) can be used. In this control, the threshold value Pq is calculated every time the flow rate Q changes.
Pq = (Q/Qr) ^α × ΔP × β (here, Q: flow rate, Qr: rated flow rate, α, β: constants) (i)
By calculating the threshold value of the differential pressure .DELTA.P in real time according to such calculation formula (i), the control means 7 can also operate the cleaning liquid jetting means 5 appropriately.

3. Effect As described above, in the ballast water treatment apparatus 100 of the present embodiment, the control means 7 compares the differential pressure ΔP of the filter 2 detected by the pressure sensor 6 with the threshold value Pq set based on the flow rate Q. controls the operation of the cleaning liquid ejecting means 5 . With such a configuration, even when the flow rate Q of ballast water flowing through the filter 2 changes, it is possible to appropriately operate the cleaning liquid jetting means 5 according to the flow rate Q to clean the filter 2 . ing.

Specifically, for example, when an ultraviolet reactor is installed in the outflow line L2, consider the case where the flow rate Q is lowered in order to appropriately irradiate the ultraviolet rays. In this case, if the threshold value Pq is set to a constant value, even if the filter clogging progresses, if the flow rate Q is small, the differential pressure for ejecting the cleaning liquid may not be reached, and cleaning may not be performed appropriately. However, the control means 7 of this embodiment sets the threshold value Pq small when the flow rate Q of the ballast water is small. Therefore, even if the value of the differential pressure ΔP is small, it can be determined that the filter 2 is clogged, and the cleaning liquid can be ejected to suppress clogging of the filter.

Conversely, when the flow rate Q is large, the differential pressure ΔP will take a slightly large value even if the filter 2 is not clogged. can be suppressed.

4. Modifications The present invention can also be implemented in the following modes.
・In the above embodiment, the control means 7 is configured to set three thresholds, the first threshold Pq1 to the third threshold Pq3, according to the flow rate Q of the ballast water. It is also possible to set threshold values in two steps or four steps or more. In addition, the control means 7 can perform control to proportionally change the threshold value Pq without permission according to the flow rate Q of the ballast water.
In the above embodiment, the operation of the cleaning liquid jetting means 5 was described as an object to be controlled by the control means 7, which performs control by comparing the differential pressure ΔP with the threshold value Pq set based on the flow rate Q. is not limited to the operation of the cleaning liquid jetting means 5 . For example, the control means 7 can also control the flow rate Q itself of the liquid filtered by the filter 2 by comparing the differential pressure ΔP with a threshold value Pq set based on the flow rate Q. In addition, the control means 7 can also control the operation of the ballast water treatment device 100 itself (such as stopping the purification process) by comparing the differential pressure ΔP with a threshold value Pq set based on the flow rate Q. . In addition, two or more of the operation of the cleaning liquid jetting means 5, the flow rate Q of the liquid filtered by the filter 2, and the operation of the ballast water treatment device 100 are set as a threshold value set based on the flow rate Q and the differential pressure ΔP. It is also possible to adopt a configuration in which control is performed by comparing with Pq. In the case where a configuration for controlling the flow rate Q itself of the liquid filtered by the filter 2 and a configuration for controlling the operation of the ballast water treatment device 100 itself are included, the ballast water treatment device 100 is provided with the cleaning liquid ejection means 5. It doesn't have to be. That is, the ballast water treatment apparatus 100 that does not have the cleaning liquid jetting means 5 is also subject to the present invention.
- Although the ballast water treatment apparatus 100 in the said embodiment was the structure which relatively rotates the filter 2 with respect to the discharge means 4, it does not restrict to this. That is, the present invention may be applied to a ballast water treatment apparatus having a configuration in which the discharge means 4 (discharge nozzle 41) rotates with respect to the fixed filter 2. FIG. Moreover, it is also possible to apply the present invention to a ballast water treatment system in which both the discharge nozzle 41 and the filter 2 do not rotate.
- In the above-described embodiment, the discharging means 4 is arranged inside the filter 2 , but it is also possible to arrange the discharging means 4 outside the filter 2 . That is, the discharge means 4 may be arranged on the primary side of the filter 2 or may be arranged on the secondary side of the filter 2 .
- Although the flowmeter 9 was provided in the outflow line L2 in the said embodiment, it does not restrict to this. That is, the flow meter 9 can be arranged at any position on the flow path of the ballast water as long as it can detect the flow rate of the ballast water that flows through the filter 2 and is treated.
- In the above embodiment, the present invention is applied to a ballast water treatment device that is used in a ship and treats ballast water, but the present invention is not limited to this. That is, the present invention may be applied to a water treatment apparatus for treating sea water, river water, lake water, pond water, industrial water, and the like. Furthermore, it can be applied to a liquid treatment apparatus for treating liquids other than water (for example, oil) instead of a water treatment apparatus for treating water.

Reference Signs List 1: casing 2: filter 3: filter rotating means 4: discharging means 5: cleaning liquid ejecting means (controlled object)
6: Pressure sensor 7: Control means 8: Pump 9: Flow meter 11: Lid portion 12: Bottom portion 13: Upper closing portion 14: Lower closing portion 15: Inlet 16: Outlet 18: Bearing member 19: Bearing member 31: Upper rotating shaft member 32 : Lower rotating shaft member 33 : Motor 41 : Discharge nozzle 42 : Discharge pipe 51 : Washing nozzle 52 : Washing line 53 : Washing pump 54 : Open/close valve 61 : Primary side sensor 62 : Secondary side sensor 100 : Ballast water treatment system (liquid treatment system)
L1: Introduction line L2: Outflow line ΔP: Differential pressure P1: Primary pressure P2: Secondary pressure Pq: Threshold value Pq1: First threshold value Pq2: Second threshold value Pq3: Third threshold value Q: Flow rate V1: On-off valve V2: On-off valve

Claims (2)

A ballast water treatment system comprising a filter,
comprising a pressure sensor, a flow meter, cleaning liquid ejecting means, and control means,
the pressure sensor is configured to detect primary and secondary pressures of the filter;
the flow meter is configured to detect the flow rate of ballast water filtered by the filter;
the cleaning liquid ejecting means is configured to eject cleaning liquid to clean the filter;
The control means sets a threshold for the differential pressure between the primary pressure and the secondary pressure based on the flow rate of the ballast water detected by the flowmeter, and the differential pressure detected by the pressure sensor is equal to or less than the threshold. The ballast water treatment apparatus stops the cleaning liquid jetting means when , and operates the cleaning liquid jetting means to start washing when the differential pressure is greater than the threshold value. The ballast water treatment system according to claim 1,
comprising ejecting means and rotating means,
The filter is formed in a cylindrical shape,
The discharge means comprises a discharge nozzle and a discharge pipe,
the discharge nozzle is arranged to face the filter on the primary side of the filter;
The discharge pipe is arranged to discharge water introduced from the discharge nozzle to the outside of the ballast water treatment device,
The ballast water treatment system, wherein the rotating means is configured to rotate the filter.

Images