JP2013099969A - Pump with flow measurement function, and ballast water treatment device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure pump flow arranged in a narrow space, with high accuracy.SOLUTION: The pump with flow measurement functions includes: a pump having a first pressure outlet formed on the downstream side of an intake-side flange and a second pressure outlet formed on the upstream side of a discharge-side flange; first and second pressure sensors arranged in the first and second pressure outlets, respectively; a memory part for storing in advance flow characteristics showing the relationship between the difference in detected pressures between the first and second pressure sensors and the flow; a calculation part for calculating a difference between the pressures actually obtained by the first and second pressure sensors; and a computing part for computing the flow on the basis of the difference and the flow characteristics.

Description

  The present invention relates to a pump with a flow rate measuring function and a ballast water treatment apparatus using the pump.

Conventionally, it has been stipulated that the flow rate of a pump is measured by installing an orifice type flow meter, a Pitot tube type flow meter, or an electromagnetic type flow meter in a straight pipe part that is five times or more the pipe diameter (non-patent document). 1).
Therefore, if the pump installation space is narrow as in a ship, the pump inlet and outlet pipes are bent and the straight pipe section is short, the flow meter cannot be installed or the measurement accuracy can be improved even if it can be installed. There was a problem that it was not guaranteed.
On the other hand, two pressure gauges that measure fluid pressure are provided on the suction side and discharge side of the pump, and the pump head is calculated from the deviation in pressure measured by the two pressure gauges, and the flow rate is calculated from the calculated head. There is known a pump flow meter that calculates the above (for example, see Patent Document 1).

JP-A-62-815

JIS B 8301

By the way, in order to calculate the pump head in this way, when the pressure measured by the pressure gauges provided on the suction side and the discharge side of the pump is used, the suction side pressure gauge is connected to the straight pipe from the flange of the suction side straight pipe of the pump. The discharge side pressure gauge is provided at a distance of twice or more the pipe diameter from the flange of the discharge side straight pipe (see JIS B 8301).
Therefore, the method of calculating the flow rate based on the head calculated from the pressure on the suction side and the discharge side of the pump also has a straight pipe portion at least twice the pipe diameter at the upstream and downstream sides of the suction and discharge side flanges of the pump. Since it is necessary, there is a problem that it is difficult to apply when the pipe line is bent immediately upstream of the suction flange or immediately downstream of the discharge flange.

  The present invention has been made in consideration of such circumstances, and a pump with a flow rate measurement function capable of accurately measuring the flow rate even if the pipe line is bent immediately upstream or downstream of the flange of the pump, and A ballast water treatment apparatus using the same is provided.

  The present invention includes a pump having a first pressure outlet on the downstream side of the suction side flange and a second pressure outlet on the upstream side of the discharge side flange, and first and second pressure outlets respectively installed on the first and second pressure outlets. Actually obtained from the first and second pressure sensors, the first and second pressure sensors, the storage unit that stores in advance the flow rate characteristics indicating the relationship between the detected pressure difference between the first and second pressure sensors and the flow rate. The present invention provides a pump with a flow rate measurement function comprising a calculation unit that calculates a difference in detected pressure and a calculation unit that calculates a flow rate from the calculated difference and the flow rate characteristic.

  According to the present invention, since the pressure sensors are provided on the downstream side of the suction flange and the upstream side of the discharge flange, a straight pipe portion is not necessary in the pipe line upstream of the suction flange and downstream of the discharge flange, and the flow rate is saved in a space-saving manner. It can measure with high accuracy.

It is principal part sectional drawing of the pump which concerns on 1st Embodiment of this invention. It is an expanded sectional view of the pressure outlet of the pump shown in FIG. It is a block diagram which shows the electric circuit of the flowmeter of the pump which concerns on 1st Embodiment of this invention. It is a characteristic view concerning a 1st embodiment of this invention. It is explanatory drawing which shows the ballast water treatment apparatus of 2nd Embodiment of this invention. It is explanatory drawing which shows the ballast water treatment apparatus of 3rd Embodiment of this invention. It is explanatory drawing which shows the ballast water treatment apparatus of 4th Embodiment of this invention.

  The flowmeter of the present invention is characterized by a pump having a first pressure outlet on the downstream side of the suction side flange and a second pressure outlet on the upstream side of the discharge side flange, and the first and second pressure outlets. A first and a second pressure sensor respectively installed; a storage unit for storing in advance a flow rate characteristic indicating a relationship between a detected pressure difference between the first and second pressure sensors and a flow rate; and a first and a second pressure A calculation unit that calculates a difference in detection pressure actually obtained from the sensor, and a calculation unit that calculates a flow rate from the calculated difference and the flow rate characteristic.

  From another viewpoint, the present invention provides a pump having a first pressure outlet on the downstream side of the suction side flange and a second pressure outlet on the upstream side of the discharge side flange, and the first and second pressure outlets. The first and second pressure sensors installed, the rotational speed sensor for detecting the rotational speed of the pump, and the flow rate indicating the relationship between the difference between the detected pressures of the first and second pressure sensors, the rotational speed of the pump, and the flow rate. A storage unit for storing characteristics in advance, a calculation unit for calculating a difference between detected pressures actually obtained from the first and second pressure sensors, a flow rate based on the calculated difference, the detected rotational speed, and the flow rate characteristic. A pump with a flow rate measurement function provided with a calculation unit that calculates the above is provided.

  From still another aspect, the present invention provides a seawater intake port for taking in seawater, a ballast pump for sucking seawater and supplying it to a ballast tank, a processing member for processing seawater supplied to the ballast tank, and a flow rate of the ballast pump A ballast water treatment device is provided, wherein the ballast pump is a pump with a flow rate measuring function.

In the ballast water treatment apparatus, the treatment member may be an injection member that injects a treatment chemical into seawater, and the control unit may control the injection amount of the chemical according to the flow rate of the ballast pump.
The processing member may be an ozone injection member that injects ozone into seawater, and the control unit may control the ozone injection amount according to the flow rate of the ballast pump.
The processing member may be a chlorine injection member that injects chlorine into seawater, and the control unit may control the amount of chlorine injected according to the flow rate of the ballast pump.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
First Embodiment FIG. 1 is a cross-sectional view of an essential part of a centrifugal pump according to a first embodiment of the present invention.
As shown in FIG. 1, the centrifugal pump 1 includes a main body casing 2 and a bearing casing 3. The main body casing 1 includes the impeller 4 inside, and includes a suction side flange 12 at the suction port 16 and a discharge side flange 13 at the discharge port 17. The suction port 16 is formed with a first pressure extraction port 40 downstream of the suction side flange 16, and the discharge port 17 is formed with a second pressure extraction port 41 upstream of the discharge side flange 13.

  FIG. 2 is a cross-sectional view showing the structure of the first and second pressure outlets 40 and 41. The first and second pressure outlets 40 and 41 are formed from a female screw hole for mounting a sensor and a pressure outlet pore. Thus, the pore diameter d is 3 to 6 mm, the pore length L ≧ 2.5d, and the pore tip r ≦ d / 10.

  The first pressure sensor 14 and the second pressure sensor 15 are fixed to the first pressure outlet 40 and the second pressure outlet 41 with screws, respectively. As the first pressure sensor 14 and the second pressure sensor 15, for example, model JTG940A manufactured by Yamatake Corporation is preferably used.

The impeller 4 is fixed to one end of a rotating shaft 5, and the rotating shaft 5 is rotatably supported by two bearings 7 and 8. The rotary shaft 5 is sealed by a shaft seal portion 6 and the other end is connected to one end of the output shaft of the motor 9 by a coupling 10.
A rotation speed sensor 11 that measures the rotation speed N of the pump 1 is coupled to the other end of the output shaft of the motor 9. Note that the rotational speed sensor 11 is not required when the rotational speed of the motor 9 is always constant.

FIG. 3 is an electric circuit diagram of the flow rate measuring unit of the pump according to the first embodiment of the present invention. As shown in the figure, the flow rate measurement unit 42 includes a storage unit 19, a calculation unit 20, and a calculation unit 21.
The flow rate measuring unit 42 receives output signals from the first pressure sensor 14, the second pressure sensor 15, and the rotational speed sensor 11, processes the output signals, and outputs them to the display unit 18 and other devices. Yes. The flow rate measuring unit 42 includes a microcomputer including a CPU, a ROM, and a RAM.

  In the storage unit 19, the difference ΔP between the detected pressure P1 of the first pressure sensor 14 and the detected pressure P2 of the second pressure sensor as shown in FIG. 4 obtained in the preliminary test, the rotational speed N of the pump 1, and the flow rate A flow rate characteristic indicating the relationship with Q is stored in advance.

In FIG. 3, curve (a) is when the rotational speed N is the rated speed N ₀ (100%), and curve (b) is when the rotational speed N is 0.8N ₀ , which is reduced to 80% of the rated speed N ₀ . curve (c) shows the relationship between ΔP and Q when the 0.6 N ₀ of the rotational speed N is reduced to 60% of N _0.

The operation in such a configuration will be described.
In the spiral pump 1 shown in FIG. 1, when the impeller 4 is driven by the motor 9, fluid is sucked into the suction port 16 and discharged from the discharge port 17.

The first pressure sensor 14 measures the pressure P 1 downstream of the suction side flange 12, and the second pressure sensor 15 measures the pressure P 2 upstream of the discharge side flange 13.
The rotational speed sensor 11 measures the rotational speed N of the impeller 4, that is, the rotational speed N of the centrifugal pump 1. These measured values P1, P2, and N are input to the flow rate measuring unit 42.

In the flow rate measurement unit 42, the calculation unit 20 calculates a difference ΔP between the measurement value P1 of the first pressure sensor 14 and the measurement value P2 of the second pressure sensor 15. Then, the calculation unit 21 calculates the flow rate Q from the calculated ΔP, the measured value N of the rotation speed sensor 11, and the flow rate characteristic of FIG. 3 stored in advance in the storage unit 19. That is, the arithmetic unit 21 when the variation in N = N _0, 0.8N ₀ or 0.6 N _0, respectively curve (a), (b), calculates a Q corresponding to ΔP based on (c).

When the _value fluctuates to N = 0.9N ₀ or 0.7N ₀ , the corresponding characteristic curve is instantly created by mathematical complementary calculation each time based on the curves (a), (b) and (c). Then, the flow rate Q is calculated from the created new characteristic curve. The calculated flow rate Q is output as an electric signal to the display unit 18 and other desired devices. If the rotational speed N is always constant, the calculation unit 21 can naturally calculate Q from only one curve, ignoring the output of the rotational speed sensor 11.

Second Embodiment FIG. 5 is an explanatory view showing a ballast water treatment apparatus according to a second embodiment of the present invention.
As shown in the figure, the ballast water treatment apparatus includes a seawater intake unit 22, a strainer 23, a filter 24, a chemical injection unit 25 for injecting a chemical for treatment, and the centrifugal pump 1 of the first embodiment. The special pipe 26 and the ballast tank 27 are provided, and these are connected in series by pipes (pipes) 28a to 28f.

  The drug injection unit 25 is connected to a drug storage tank 31 through a fixed gear pump 30. The medicine storage tank 31 and the metering gear pump 30 are connected by a pipe line 29a, and the metering gear pump 30 and the medicine injection part 25 are connected by a pipe line 29b.

  Further, the spiral pump 1 includes the flow rate measuring unit 42 of the first embodiment, and the control device 32a receives a signal representing the flow rate Q of the spiral pump 1 from the flow rate measuring unit 16, and corresponds to the flow rate Q of the quantitative gear pump 30. The drive speed is controlled. The control device 32 a includes a microcomputer including a CPU, a ROM, and a RAM, and a driver circuit that drives the quantitative gear pump 30.

  The strainer 23 has a function of removing an object having an outer diameter of 10 mm or more (for example, jellyfish or dust (vinyl, wood pieces, plastic bottles, etc.)). The filter 24 has a function of removing an object having an outer diameter of 300 μm or more. The special pipe 26 is a physical means for generating shear stress and cavitation in the ballast water.

This is a pipe with two slit plates (plate thickness 4 mm, slit width 0.3 mm, slit interval 4 mm, slit number 36, slit interval 5 mm). Those having a length of 200 mm and a pipe length of 600 mm are preferably used.
Examples of the drug stored in the drug storage tank 31 include an aqueous hydrogen peroxide solution having a concentration of 3 to 60% that is commercially available for industrial use.

The operation in such a configuration will be described.
When the vortex pump 1 is driven by the motor 9 (FIG. 1), seawater is drawn from the intake portion 22 and passes through the strainer 23, the filter 24, the drug injection portion 25, the vortex pump 1 and the special pipe 26 to the ballast tank 27. Supplied.

  At this time, the flow rate Q of the centrifugal pump 1 is measured by the flow rate measurement unit 42 in the same manner as in the first embodiment. The drug storage tank 31 stores a 45 wt% aqueous hydrogen peroxide solution in advance. The control device 32 drives the metering gear pump 30 to supply the aqueous peroxide solution from the drug storage tank 31 to the drug injection part 25. In the drug injection unit 25, hydrogen peroxide solution quantified so as to have a desired constant concentration in the range of 10 to 300 mg / L of hydrogen peroxide concentration with respect to the ballast water at the flow rate Q is injected.

  Therefore, the aquatic organisms contained in the seawater taken from the water intake unit 22 are efficiently removed by the action of hydrogen peroxide and the shear stress and cavitation action of the special pipe 26, and the dissolved oxygen in the ballast water is set to an appropriate amount. The hydrogen peroxide in the ballast water is rapidly decomposed.

Third Embodiment FIG. 6 is an explanatory view showing a ballast water treatment apparatus according to a third embodiment of the present invention.
As shown in the figure, the ballast water treatment apparatus includes a seawater intake unit 22, a strainer 23, a filter 24, an ozone injection unit 33 for injecting treatment ozone, and the vortex pump 1 of the first embodiment. The special pipe 26 and the ballast tank 27 are provided, and these are connected in series by pipes (pipes) 28a to 28f.
The ozone injection part 33 is connected to the flow rate adjustment valve 36 via a gas pipe line 35b, and the flow rate adjustment valve 36 is connected to the ozone storage tank 34 via a gas pipe line 35a.

  The centrifugal pump 1 includes the flow rate measurement unit 42 of the first embodiment, and the control device 32b receives a signal representing the flow rate Q of the centrifugal pump 1 from the flow rate measurement unit 16 and controls the flow rate adjustment valve 36 corresponding to the flow rate Q. It is supposed to be. The control device 32b includes a microcomputer including a CPU, a ROM, and a RAM, and a driver circuit that drives the flow rate adjusting valve.

  That is, in this embodiment, the medicine injection section 25, the metering gear pump 30, and the medicine storage tank 31 in the second embodiment are replaced with the ozone injection section 33, the flow rate adjusting valve 36, and the ozone storage tank 34, and the control device 32a. Is replaced with the control device 32b. Other configurations are the same as those of the second embodiment (FIG. 4).

The operation in such a configuration will be described.
When the vortex pump 1 is driven by the motor 9 (FIG. 1), seawater is taken from the intake portion 22 and passes through the strainer 23, the filter 24, the ozone injection portion 33, the vortex pump 1 and the special pipe 26 to the ballast tank 27. Supplied.

  At this time, the flow rate Q of the centrifugal pump 1 is measured by the flow rate measurement unit 42 in the same manner as in the first embodiment. The control device 32 b drives the flow rate adjustment valve 36 to supply ozone from the ozone storage tank 34 to the ozone injection part 33. In the ozone injection unit 33, an amount of ozone adjusted so that the ozone concentration becomes a desired constant concentration (for example, 4 mg / L) with respect to the ballast water at the flow rate Q is injected.

  Therefore, the aquatic organisms contained in the seawater taken from the water intake unit 22 are efficiently removed by the action of ozone and the shear stress and cavitation action of the special pipe 26, and the dissolved oxygen of the ballast water is maintained at an appropriate amount. In addition, hydrogen peroxide in the ballast water is rapidly decomposed.

Fourth Embodiment FIG. 7 is an explanatory view showing a ballast water treatment apparatus according to a fourth embodiment of the present invention.
As shown in the figure, this ballast water treatment apparatus includes a seawater intake unit 22, a strainer 23, a filter 24, the centrifugal pump 1 of the first embodiment, and a chlorine injection unit 37 for injecting chlorine for treatment. The special pipe 26 and the ballast tank 27 are provided, and these are connected in series by pipes (pipes) 28a to 28f.
In addition, the chlorine injection part 37 is connected to a chlorine generator 38 through a gas pipe 39.

  The vortex pump 1 includes the flow rate measurement unit 42 of the first embodiment, and the control device 32c receives a signal representing the flow rate Q of the vortex pump 1 from the flow rate measurement unit 16, and corresponds to the flow rate Q of the chlorine gas generation device 38. The amount of chlorine gas produced is controlled. The control device 32c includes a microcomputer including a CPU, a ROM, and a RAM.

  That is, in this embodiment, the medicine injection part 25, the metering gear pump 30 and the medicine storage tank 31 in the second embodiment are replaced with the chlorine injection part 37 and the chlorine generator 38, and the control device 32a is replaced with the control device 32c. It is a replacement. Other configurations are the same as those of the second embodiment (FIG. 4). However, in this embodiment, the chlorine injection part 37 is installed downstream of the centrifugal pump 1.

The operation in such a configuration will be described.
When the vortex pump 1 is driven by the motor 9 (FIG. 1), seawater is taken from the intake portion 22, passed through the strainer 23, filter 24, vortex pump 1, chlorine injection portion 37 and special pipe 26 to the ballast tank 27. Supplied.

  At this time, the flow rate Q of the centrifugal pump 1 is measured by the flow rate measurement unit 42 in the same manner as in the first embodiment. The control device 32 c controls the chlorine generator 38 to supply the chlorine injecting unit 37 with an amount of chlorine corresponding to the flow rate Q. In the chlorine injection part 37, an amount of chlorine adjusted so that the chlorine concentration becomes a desired constant concentration is injected into the ballast water at the flow rate Q.

  Therefore, the aquatic organisms contained in the seawater taken from the water intake unit 22 are efficiently removed by the action of chlorine and the shear stress and cavitation action by the special pipe 26, and the dissolved oxygen of the ballast water is maintained at an appropriate amount. In addition, hydrogen peroxide in the ballast water is rapidly decomposed.

DESCRIPTION OF SYMBOLS 1 Centrifugal pump 2 Main body casing 3 Bearing casing 4 Impeller 5 Rotating shaft 6 Shaft seal part 7 Bearing 8 Bearing 9 Motor 10 Coupling 11 Rotation speed sensor 12 Suction side flange 13 Discharge side flange 14 First pressure sensor 15 Second pressure sensor 16 Suction port 17 Discharge port 18 Display unit 19 Storage unit 20 Calculation unit 21 Calculation unit 22 Water intake unit 23 Strainer 24 Filter 25 Drug injection unit 26 Special pipe 27 Ballast tanks 28a to 28f Pipe lines 29a and 29b Pipe line 30 Metering gear pump 31 Drug container Tanks 32a to 32c Controller 33 Ozone injection part 34 Ozone storage tanks 35a, 35b Gas pipe line 36 Flow rate adjusting valve 37 Chlorine injection part 38 Chlorine generator 39 Gas pipe line 40 Pressure outlet 41 Pressure outlet 42 Flow rate measuring part

Claims (6)

  A pump having a first pressure extraction port on the downstream side of the suction side flange and a second pressure extraction port on the upstream side of the discharge side flange, and first and second installed at the first and second pressure extraction ports, respectively. A pressure sensor, a storage unit that stores in advance a flow rate characteristic indicating a relationship between a detected pressure difference between the first and second pressure sensors and a flow rate, and a detected pressure actually obtained from the first and second pressure sensors. A pump with a flow rate measurement function, comprising: a calculation unit that calculates a difference; and a calculation unit that calculates a flow rate from the calculated difference and the flow rate characteristic.   A pump having a first pressure extraction port on the downstream side of the suction side flange and a second pressure extraction port on the upstream side of the discharge side flange, and first and second installed at the first and second pressure extraction ports, respectively. A pressure sensor, a rotation speed sensor for detecting the rotation speed of the pump, and a storage unit for previously storing a flow rate characteristic indicating a relationship between a difference between detected pressures of the first and second pressure sensors, a rotation speed of the pump, and a flow rate And a calculation unit that calculates a difference between the detected pressures actually obtained from the first and second pressure sensors, and a calculation unit that calculates the flow rate from the calculated difference, the detected rotation speed, and the flow rate characteristic. Pump with measurement function.   Seawater intake port for taking in seawater, ballast pump for sucking seawater and supplying it to the ballast tank, processing member for processing seawater supplied to the ballast tank, and controlling the processing capacity of the processing member according to the flow rate of the ballast pump A ballast water treatment apparatus, wherein the ballast pump is a pump with a flow rate measuring function according to claim 1 or 2.   The ballast water treatment apparatus according to claim 3, wherein the treatment member is an injection member that injects a treatment chemical into seawater, and the control unit controls an injection amount of the chemical according to a flow rate of the ballast pump.   The ballast water treatment apparatus according to claim 3, wherein the treatment member is an ozone injection member that injects ozone into seawater, and the control unit controls the injection amount of the ozone in accordance with a flow rate of the ballast pump.   The ballast water treatment apparatus according to claim 3, wherein the treatment member is a chlorine injection member that injects chlorine into seawater, and the control unit controls an injection amount of chlorine according to a flow rate of the ballast pump.

Images