JP2020131154A - Liquid treatment apparatus - Google Patents

Abstract

To provide a liquid treatment apparatus capable of properly controlling a control object, even when a rate of flow at which the object circulates through a filter is small, in controlling the control object according to differential pressure before and after the filter.SOLUTION: Provided is a liquid treatment apparatus 100 with a filter 2, that comprises a pressure sensor 6, a flow meter 9, and controlling means 7. In the liquid treatment apparatus 100, the pressure sensor 6 is configured to detect a primary pressure P1 and a secondary pressure P2 in the filter 2, and the flow meter 9 is configured to detect a flow rate of a liquid subjected to filtration treatment by the filter 2. Further, the controlling means 7 controls a control object by comparing a differential pressure ΔP of the primary pressure P1 and the secondary pressure P2 detected by the pressure sensor 6 to a threshold Pq set on the basis of the flow rate of the liquid detected by the flow meter 9.SELECTED DRAWING: Figure 1

Description

The present invention relates to a liquid processing apparatus having a filter.

When a ship such as a tanker unloads the cargo of crude oil and then sails toward the destination again, water called ballast water is usually stored in a ballast tank in order to balance the ship while sailing. Such vessels are provided with a water treatment device (ballast water treatment device) for purifying and treating ballast water in order to prevent the destruction of the ecosystem due to the injection and drainage of ballast water.

As a kind of ballast water treatment apparatus, a type (filtration apparatus) for filtering ballast water by arranging a cylindrical filter in a casing is known. In this method, constant cleaning of the filter is important to prevent blockage of the filter.

Therefore, as a configuration for removing foreign matter accumulated on the filter, for example, Patent Document 1 describes a configuration provided on the secondary side of the filter and provided with a cleaning nozzle for ejecting cleaning water toward the filter. There is.

Japanese Unexamined Patent Publication No. 2004-141785

By the way, in the filtration device provided with such a cleaning nozzle, the ejection of cleaning water is controlled based on the differential pressure before and after the filter. However, when the flow rate of a liquid such as water flowing through the filter is small, there is a problem that even if the filter is clogged, the cleaning is not performed because the differential pressure for ejecting the cleaning liquid is not reached. Further, if the flow rate is increased in such a state, the differential pressure may increase, which may adversely affect the filter and the like.

Furthermore, not only the control of the ejection of the washing water, but also the flow rate of the liquid such as water flowing through the filter and the operation of the controlled object such as the ballast water treatment device itself can be controlled based on the differential pressure before and after the filter. Conceivable. However, even in this case, it is difficult to perform appropriate control because the differential pressure does not increase when the flow rate of the flowing liquid such as water is small.

The present invention has been made in view of such circumstances, and when the control target is controlled based on the differential pressure before and after the filter, the control target can be appropriately controlled even when the flow rate flowing through the filter is small. It is an object of the present invention to provide a liquid processing apparatus which can be controlled.

According to the present invention, the liquid processing apparatus including a filter includes a pressure sensor, a flow meter, and a control means, and the pressure sensor is configured to detect the primary pressure and the secondary pressure of the filter. 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. A liquid processing apparatus is provided that controls a controlled object by comparing with a threshold value set based on the flow rate of the liquid detected by the meter.

According to the present invention, since 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, the flow rate of the liquid flowing through the filter changes. Even if this is the case, it is possible to properly clean the filter.

Hereinafter, various embodiments of the present invention will be illustrated. The embodiments shown below can be combined with each other.

Preferably, the control target is at least one of the following (1) to (3).
(1) Operation of the cleaning liquid ejecting means configured to eject the cleaning liquid toward the filter (2) Flow rate of the liquid filtered by the filter (3) Operation of the liquid processing apparatus

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

Preferably, the filter includes a discharge means and a rotating means, the filter is formed in a cylindrical shape, the discharge means includes a discharge nozzle and a discharge pipe, and the discharge nozzle is the filter on the primary side of the filter. The discharge pipe is arranged so as to discharge the water introduced from the discharge nozzle to the outside of the liquid treatment device, and the rotating means is configured to rotate the filter.

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

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

The ballast water treatment device 100 as a liquid treatment device according to the embodiment of the present invention is introduced for purifying ballast water in a ballast device installed on a ship. The "ballast water" in the present specification is introduced (inflowed) into the ballast water treatment device 100 regardless of whether it is introduced into the ballast tank (not shown) or after it is discharged from the ballast tank. All the water taken into the ship, whether before or after being discharged (outflowed) from the ballast water treatment device 100, is referred to as "ballast water". In addition, the ballast water taken into the ship shall include seawater, freshwater, brackish water, and the like.

1. 1. Configuration As shown in FIG. 1, the ballast water treatment device 100 of the present embodiment includes a cylindrical casing 1, a cylindrical filter 2, and a filter rotating means 3. The cylindrical filter 2 is arranged in the casing 1 and filters the ballast water before the filtration treatment such as seawater that has flowed into the inside (primary side) and discharges it to the outside (secondary side). The filter rotating means 3 rotates the filter 2 about its axis.

Further, the ballast water treatment device 100 is provided on the discharge means 4 for discharging the ballast water on the primary side of the filter 2 and the secondary side of the filter 2 for cleaning the filter 2 during the filtration treatment, and faces the filter 2. It is provided with a cleaning liquid ejection 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. Hereinafter, each configuration will be specifically described.

The casing 1 is formed in a cylindrical shape, and the upper opening is sealed by the lid 11 and the lower opening is sealed by the bottom 12. The upper opening of the cylindrical filter 2 arranged in the casing 1 is sealed by the upper closing portion 13, and the lower opening is closed by the lower closing portion 14. With these configurations, the inside of the filter 2 (primary side) is separated from the casing 1 and the filter 2 (secondary side). The filter 2 is formed, for example, by bending a metal plate having a large number of through holes into a cylindrical shape and welding a pair of side edges extending in the axial direction of the cylindrical shape.

At the lower part of the casing 1, an introduction port 15 for introducing the ballast water before the filtration treatment into the inside of the filter 2 is provided. The introduction line L1 is connected to the introduction port 15. A pump 8 of a ballast device that pumps ballast water from the on-off valve with the on-off valve V1 sandwiched is connected to the introduction line L1. Further, an outlet 16 is provided on the side portion of the casing 1 from which the ballast water after the filtration treatment that has passed through the filter 2 flows out.

The ballast water that flows through the introduction line L1 and is introduced from the introduction port 15 enters the filter 2 through the lower rotary 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 flows out from the outlet 16. The ballast water after the filtration treatment that flows out from the outflow port 16 flows through the outflow line L2 and is stored in a ballast tank (not shown).

The outflow line L2 is provided with an on-off valve V2 and a flow meter 9. The flow meter 9 detects the flow rate of the ballast water processed by flowing through the ballast water treatment device 100 (filter 2). It is also preferable to arrange another purification means such as an ultraviolet treatment device (not shown) that kills organisms by 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 rotation shaft member 31. Further, the upper rotary shaft member 31 penetrates the lid portion 11 of the casing 1 and is rotatably and liquid-tightly supported by the lid portion 11 via the sealed bearing member 18. The lower rotary shaft member 32 penetrates the bottom portion 12 of the casing 1 and is rotatably and liquid-tightly supported by the bottom portion 12 via the sealed bearing member 19. The lower rotary shaft member 32 is a tubular body that communicates with the inside of the filter 2 and projects from the bottom 12 of the casing 1 to the outside of the casing 1.

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

The discharge nozzle 41 is arranged so that its tip portion opens in a slit shape toward the inner peripheral surface (primary side surface) of the filter 2 and faces the filter 2. The base end portion of the discharge nozzle 41 is connected to the discharge pipe 42. In the present embodiment, the discharge nozzles 41 are provided in four rows at 90-degree intervals in the circumferential direction, three in each vertical direction, for a total of twelve (in FIG. 1, the nozzles other than those extending in the right direction are omitted). .. Then, in order to eliminate the unsucked portion between the discharge nozzles 41 arranged above and below, the height direction of each row is such that the discharge nozzles 41 of the other row are located between the discharge nozzles 41 of one row. The positions of are staggered.

The upper side of the discharge pipe 42 is arranged inside the filter 2, and the lower side extends to the outside of the casing 1. More specifically, the upper portion of the discharge pipe 42 is arranged at a position corresponding to the central axis of the filter 2, the upper end portion is closed and the lower end portion is open. The upper end of the discharge pipe 42 is inserted and supported in a hole provided in the center of the upper rotary 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 extends, and penetrates the peripheral surface of the introduction port 15. Ballast water and foreign matter that have flowed through the discharge nozzle 41 are collected and circulated in the discharge pipe 42, and these are discharged to the outside of the casing 1 (ballast water treatment device 100). Further, the discharge pipe 42 of the present embodiment is provided with an adjusting valve (not shown) capable of adjusting the opening degree.

The cleaning liquid ejection means 5 includes a plurality of cleaning nozzles 51, a cleaning line 52, and a cleaning pump 53. The plurality of cleaning nozzles 51 are provided on the side portion of the casing 1, and the tip portion thereof opens in the casing, particularly toward the outer peripheral surface of the filter 2. In the present embodiment, each cleaning nozzle 51 is arranged on the same circumference as each of the plurality of arranged discharge nozzles 41. It is preferable that each cleaning nozzle 51 can eject the cleaning liquid over the entire axial direction of the filter 2, but the configuration thereof 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 the cleaning line 52 is connected to a cleaning liquid supply source (not shown). As the cleaning liquid, ballast water treated by the filter 2 can be used. However, water stored in the ballast tank, domestic water or drinking water stored for other purposes may 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. 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, specific positions of the "secondary side of the filter 2" include, for example, the space between the casing 1 and the filter 2 (including the one in which the socket is installed in the casing 1), the inside of the outlet 16, and the outflow. On line L2. However, it is not limited to these positions.

The control means 7 is a differential pressure between the primary pressure P1 and the secondary pressure P2 from the primary pressure P1 of the filter 2 detected by the primary side sensor 61 and the secondary pressure P2 of the filter 2 detected by the secondary side sensor 62. Derivation of ΔP (= P1-P2). From this differential pressure ΔP, it is possible to determine how dirty the filter 2 is. 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 flowing 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 ejection means 5 based on the differential pressure ΔP and the flow rate Q. Specific control of the cleaning liquid ejection means 5 by the control means 7 will be described later.

2. 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 in from the introduction port 15 through the introduction 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 discharging means 4. Then, the ballast water enters the space formed between the casing 1 and the filter 2 and flows out from the outlet 16. The spilled ballast water passes through the spill 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 adjusting valve installed in the discharge pipe 42, foreign matter adhering to the filter 2 can be removed from the filter 2. It is sucked from the opening of the discharge nozzle 41 together with the ballast water after filtration on the next side, and is discharged to the outside through the discharge pipe 42.

Further, during cleaning during the filtration process, the on-off valve 54 of the cleaning liquid ejection means 5 is opened and the cleaning pump 53 is driven under the control of the control means 7, and the cleaning liquid is ejected from each cleaning nozzle 51 toward the filter 2. .. When the cleaning liquid is ejected, the foreign matter accumulated on the primary side of the filter 2 is peeled off, and immediately after the peeling, the foreign matter is sucked by the discharge nozzle 41. Therefore, the foreign matter peeled off from the filter 2 is effectively sucked by the discharge nozzle 41. To.

Here, the control means 7 controls the operation of the cleaning liquid ejection means 5 by comparing the differential pressure ΔP with a predetermined threshold value Pq. The threshold value Pq is stored in a storage unit (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 ejection means 5. On the other hand, when the differential pressure ΔP is larger than the threshold value Pq, the control means 7 determines that the amount of foreign matter deposited on the filter 2 has increased, operates the cleaning liquid ejecting means 5, and starts cleaning. In the present embodiment, the "operation of the cleaning liquid ejection means 5" is the control target of the control means 7.

Then, in the present embodiment, the control means 7 changes the threshold value Pq of the differential pressure ΔP based on the flow rate Q of the flowing 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 ejection 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 processing flow rate, the threshold value Pq is raised as compared with the case where the flow rate Q is small, and the cleaning liquid ejection means 5 is not operated until the differential pressure ΔP becomes large. When the flow rate Q of the ballast water exceeds the rated processing flow rate, the threshold value Pq may be maintained or the threshold value Pq may be set even larger.

A more specific example of changing the threshold value Pq based on the flow rate Q of the flowing ballast water by the control means 7 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. When / 3 or more and less than Qr / 2 (Qr / 3 <Q <Qr / 2), the threshold Pq is set to the second threshold Pq2 (> Pq1) which is larger than the first threshold Pq1, and the flow rate Q is Qr / 2 or more. In the case of (Qr / 2 <Q), the threshold value Pq is set to a third threshold value Pq3 (> Pq2) larger than the second threshold value Pq2. When an ultraviolet reactor (not shown) is installed in the outflow line L2, a reference flow rate may be specified based on the rated flow rate of the ultraviolet reactor instead of the rated flow rate of the ballast water treatment device 100.

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

Further, as another example of changing the threshold value Pq of the differential pressure ΔP based on the flow rate Q of the flowing ballast water by the control means 7, the following calculation formula (i) can be used. In this control, the threshold value Pq is calculated each time according to the change in the flow rate Q.
Pq = (Q / Qr) ^α × ΔP × β (where Q: flow rate, Qr: rated flow rate, α, β: constant) ... (i)
The control means 7 can appropriately operate the cleaning liquid ejection means 5 by calculating and using the threshold value of the differential pressure ΔP in real time by the calculation formula (i).

3. 3. Effect As described above, in the ballast water treatment device 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 ejection means 5. With such a configuration, even when the flow rate Q of the ballast water flowing through the filter 2 changes, the cleaning liquid ejection means 5 can be appropriately operated according to the flow rate Q to clean the filter 2. ing.

Specifically, for example, in the case where the ultraviolet reactor is installed in the outflow line L2, the case where the flow rate Q is reduced in order to properly perform the ultraviolet irradiation is considered. In this case, if the threshold value Pq is set as a constant value, even if the filter is clogged, if the flow rate Q is small, the differential pressure for ejecting the cleaning liquid is not reached, so that cleaning may not be performed properly. However, the control means 7 of the present embodiment sets the threshold value Pq to be 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 the filter clogging.

On the contrary, when the flow rate Q is large, the differential pressure ΔP takes a slightly large value even if the filter 2 is not clogged, but by setting the threshold value Pq to a large value, unnecessary cleaning liquid is ejected. It is possible to suppress.

4. Modifications The present invention can also be carried out in the following embodiments.
-In the above embodiment, the control means 7 is configured to set the value of the threshold value Pq to three threshold values of the first threshold value Pq1 to the third threshold value Pq3 according to the flow rate Q of the ballast water. It is also possible to set a threshold value of 2 steps or 4 steps or more. Further, the control means 7 can also control so as 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 ejection means 5 has been described as a control target of the control means 7 for controlling the differential pressure ΔP by comparing it with the threshold value Pq set based on the flow rate Q. Is not limited to the operation of the cleaning liquid ejection means 5. For example, the control means 7 can control the flow rate Q itself of the liquid filtered by the filter 2 by comparing the differential pressure ΔP with the threshold value Pq set based on the flow rate Q. Further, the control means 7 can control the operation of the ballast water treatment device 100 itself (stop purification treatment, etc.) by comparing the differential pressure ΔP with the threshold value Pq set based on the flow rate Q. .. In addition, of the operation of the cleaning liquid ejection means 5, the flow rate Q of the liquid filtered by the filter 2, and the operation of the ballast water treatment device 100, two or more of them have a threshold value in which the differential pressure ΔP is set based on the flow rate Q. It is also possible to have a configuration that is controlled by comparing with Pq. The ballast water treatment device 100 includes the cleaning liquid ejection means 5 when the configuration includes 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. It doesn't have to be. That is, the ballast water treatment device 100 that does not have the cleaning liquid ejection means 5 is also an object of the present invention.
The ballast water treatment device 100 in the above embodiment has a configuration in which the filter 2 is rotated relative to the discharge means 4, but the present invention is not limited to this. That is, the present invention may be applied to a ballast water treatment device having a configuration in which the discharge means 4 (discharge nozzle 41) rotates with respect to the fixed filter 2. It is also possible to apply the present invention to a ballast water treatment apparatus in which both the discharge nozzle 41 and the filter 2 do not rotate.
-In the above embodiment, the discharge means 4 is arranged inside the filter 2, but it is also possible to arrange the discharge 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.
-In the above embodiment, the flow meter 9 is provided on the outflow line L2, but the present invention is not limited to this. That is, the flow meter 9 can be arranged at an arbitrary position on the ballast water flow path as long as the flow rate of the ballast water processed through the filter 2 can be detected.
-In the above embodiment, the present invention is applied to a ballast water treatment apparatus used in a ship to treat 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 water such as seas, rivers, lakes and ponds, and industrial water. Further, it can be applied to a liquid treatment device that treats a liquid other than water (for example, oil) instead of a water treatment device that treats water.

1: Casing 2: Filter 3: Filter rotating means 4: Discharge means 5: Cleaning liquid ejection means (controlled object)
6: Pressure sensor 7: Control means 8: Pump 9: Flow meter 11: Lid 12: Bottom 13: Top closure 14: Bottom closure 15: Introduction port 16: Outlet 18: Bearing member 19: Bearing member 31: Upper rotary shaft member 32: Lower rotary shaft member 33: Motor 41: Discharge nozzle 42: Discharge pipe 51: Cleaning nozzle 52: Cleaning line 53: Cleaning pump 54: On-off valve 61: Primary side sensor 62: Secondary side sensor 100: Ballast water treatment equipment (liquid treatment equipment)
L1: Introductory line L2: Outflow line ΔP: Differential pressure P1: Primary pressure P2: Secondary pressure Pq: Threshold Pq1: First threshold Pq2: Second threshold Pq3: Third threshold Q: Flow rate V1: On-off valve V2: On-off valve

Claims (4)

A liquid processing device equipped with a filter
Equipped with a pressure sensor, a flow meter, and a control means,
The pressure sensor is configured to detect the primary and secondary pressures of the filter.
The flow meter is configured to detect the flow rate of the liquid filtered by the filter.
The control means controls the control target by comparing the differential pressure between the primary pressure and the secondary pressure detected by the pressure sensor with a threshold value set based on the flow rate of the liquid detected by the flow meter. A liquid processing device that controls. The liquid processing apparatus according to claim 1.
The control target is at least one of the following (1) to (3), a liquid processing apparatus.
(1) Operation of the cleaning liquid ejecting means configured to eject the cleaning liquid toward the filter (2) Flow rate of the liquid filtered by the filter (3) Operation of the liquid processing apparatus The liquid processing apparatus according to claim 1 or 2.
The control means is a liquid processing apparatus that sets the threshold value by calculation each time or based on a table stored in advance. The liquid processing apparatus according to any one of claims 1 to 3.
Equipped with a discharge means and a rotation means,
The filter is formed in a cylindrical shape.
The discharge means includes a discharge nozzle and a discharge pipe.
The discharge nozzle is arranged so as to face the filter on the primary side of the filter.
The discharge pipe is arranged so as to discharge the water introduced from the discharge nozzle to the outside of the liquid treatment apparatus.
The rotating means is a water treatment device configured to rotate the filter.