JPH05231373A - Method for holding spare pump and vessel used therein - Google Patents

Abstract

PURPOSE:To provide a method for holding a spare pump always in a startable condition by removing air mixed in a suction line of the spare pump and a vessel used in this method. CONSTITUTION:A vessel 11 in an almost full-water condition is provided in a vacuumizing line 7 of a spare pump P2, to automatically exhaust air of staying on an upper part of the vessel. An inlet and an outlet connected to the vacuumizing line of the spare pump are provided respectively in separate suitable parts in a side surface or bottom surface of the vessel, a partitioning plate for partitioning these inlet and outlet parts is provided so as to position the lower edge in the bottom surface of the vessel and the upper edge in the upper part from the inlet, and an automatic exhausting means (comprising timer and solenoid valve or electrode and electric motor driven valve) 12 of air is provided in the upper part of the vessel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for holding a preliminary pump and a vessel used for the method, and more particularly, to always keep the auxiliary pump by removing air mixed in the suction line of the auxiliary pump and the main body of the auxiliary pump. It relates to a method that can be kept bootable and the vessel used for this method.

[0002]

2. Description of the Related Art A backup pump must be automatically started when the pump in operation stops due to some trouble or the like, and must always be kept in a state where continuous operation is possible. For example, in a pump that pumps seawater for cooling a plant, if the pump that is operating is stopped and the standby pump is not immediately activated, the operation of the entire plant must be stopped.

As a cause of the standby pump not starting, defective vacuuming (full water) of the standby pump can be mentioned.
This vacuuming (full water) failure is caused by (1) suction of air from the spare pump gland, (2) generation of holes, gaps, pinholes, etc. due to deterioration of the spare pump, (3) air separated from seawater. This is caused by the fact that the vacuum pumping line around the auxiliary pump is mixed.

Therefore, as a method of maintaining full water of the auxiliary pump, conventionally, (1) a method of using a foot valve in the suction portion of the auxiliary pump, that is, a seawater intake portion (intake portion), (2) before starting the auxiliary pump A method of operating a vacuum pump, (3) a method of constantly maintaining a vacuum with a vacuum pump or an ejector, (4) using a pump in operation to leave a vacuuming line around a preliminary pump full of water,
A method of preventing air from being mixed into the line is adopted.

[0005]

However, in the above method (1), it is necessary to install a special foot valve having corrosion resistance and a large diameter, which not only raises the equipment cost of the foot valve but also operates the foot valve. There are also defects and maintenance problems. Further, in the above method (2), it takes a certain amount of time to complete the evacuation, so that the water supply pressure is temporarily reduced. Further, in the above method (3), power costs are high and operating costs are high. In the method (4), it is impossible or extremely difficult to prevent a slight amount of air from being sucked in or mixed.

Incidentally, according to the experience of the present inventors, the number of defective times of vacuuming (full water) of the auxiliary pump when the method (4) is adopted was as high as 22 times a month. As measures against this, we investigated and repaired the air-mixed portion, and added a rising slope to the pump side during operation to prevent air from accumulating in the evacuation line. The number of defective vacuum draws (full water) was 18 times a month, which was only about 18% reduction. Therefore, it is desired to develop a measure capable of removing the air mixed in the vacuuming line around the preliminary pump.

The present invention, under the above circumstances,
The aim is to propose a method by which the standby pump can be kept in a state in which it can be activated at all times and the equipment (vessel) of a specific configuration used for this method.

[0008]

The inventors of the present invention have conducted extensive studies to achieve the above object. As a result, (1) a vacuum pumping line of a preliminary pump is provided with a vessel having a function of discharging mixed air. Together with making the vessel almost full of water, and (2) if air is mixed in the suction line of the preliminary pump and the pump body, guide the air to the vessel and remove it from the vessel. Moreover, according to (3) the automatic removal of the air, it has been found that the standby pump can be always maintained in a full water state in which it can be started.

The method for holding a preliminary pump according to the present invention is based on the above-mentioned findings. A nearly full-filled vessel is provided along the vacuum line from the top of the pump main body of the preliminary pump, and the vessel is retained above the vessel. It is characterized by automatically discharging air.

Further, the vessel of the present invention is a vessel used in the above-mentioned holding method, wherein an inlet and an outlet connected to a vacuum pumping line of a preliminary pump are provided on a side surface or a bottom surface of the vessel as appropriate. A partition plate for partitioning the inlet part and the outlet part, respectively, so that the lower edge of the partition plate is located on the bottom surface of the vessel and the upper edge is located above the inlet, It is characterized in that an automatic air discharging means is provided on the upper portion of the vessel.

Examples of the automatic air discharging means include a periodic discharging means using an electromagnetic valve and a timer, an discharging means using a motor-operated valve and an electrode to retain a certain amount of air, and the like.

[0012]

In the holding method of the present invention, the substantially full vessel provided in the vacuum evacuation line of the preliminary pump has a function of discharging the air mixed in the line. That is,
When air is mixed in the suction line of the auxiliary pump and the pump body, for example, by leaking from the outside or separation of air in seawater, the air fills the suction line and the pump body. Depending on the seawater present, it enters the vessel above via a vacuum line. The air that has entered the vessel stays in the upper portion of the water in the vessel and is automatically discharged from the upper portion. By the above-described operation, the air in the suction line of the preliminary pump is removed, the vacuum evacuation (full water) failure at the time of starting the preliminary pump is eliminated, and the preliminary pump is always kept in a startable state.

Further, in the vessel of the present invention, in a substantially full state, the above-mentioned air enters from an inlet connected to a vacuuming line of a preliminary pump provided at an appropriate position on the side surface of the vessel. The flow of this air is restricted by the partition plate whose upper edge is located above the inlet (in other words, the flow is blocked by the partition plate). The air whose flow is restricted (obstructed) has a lower specific gravity than the water filled in the vessel, and thus floats in the water and stays in the upper portion of the vessel.

On the other hand, an automatic air discharging means such as an electromagnetic valve and a timer, or an air discharging port equipped with a motor-operated valve and an electrode is provided above the vessel. The solenoid valve periodically repeats the open state and the closed state by the action of the timer, and the motor-operated valve becomes the open state when a certain amount of air stays due to the action of the electrode, and becomes the closed state when a certain amount of air is discharged. Therefore, the air staying above the vessel is automatically discharged from the air discharge port via the electromagnetic valve or the motor-operated valve which is automatically opened. With the above operation, when the vessel of the present invention is used, the air in the suction line of the preliminary pump and the pump body is effectively removed, and the preliminary pump is always kept in a startable state.

In the vessel of the present invention, when the auxiliary pump is activated, a motor-operated valve provided in the vacuum evacuation line at the top of the auxiliary pump (the automatic air-discharging means provided in the upper portion of the vessel described above). However, it is in a blocked state. When the standby pump is stopped, the motor-operated valve is opened, vacuuming of the standby pump is started again, and the standby pump is kept full of water.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flow chart showing an embodiment of the holding method of the present invention. In FIG. 1, P1 is an operating pump and P2 is a backup pump. The pump P1 in operation is
In this example, seawater is taken from the suction pit (intake port) 1, and is sent from a line 13 to a seawater use plant (not shown) via a suction line 2'and a delivery line 3 '.

On the other hand, the auxiliary pump P2 is first evacuated (filled with water) by the vacuum pump VP, and then the valve 4, the motor-operated valve 5 in the evacuation line 7 at the top of the auxiliary pump P2 and the pump P1 in operation. The valve 8'in the vacuum line 9'for the suction line is opened. Next, seawater is taken from the intake 1 by the suction force of the pump P1 during operation,
Seawater flows into the suction line 2, the preliminary pump body P2, the vacuuming line 7, the vessel 11, the vacuuming line 7'on the side of the pump P1 in operation, and the vacuuming line 9'for the suction line. At this time, the vacuuming (full water) state of the auxiliary pump P2 is electrically performed by the full water detector 6, and the full water state (the state in which the air is completely lost) in each of the above lines is the glass window 10, 10 '. By visual inspection.

As described above, when the preliminary pump P2 is kept full of water, when air is mixed in from the ground of the preliminary pump P2 or when air is separated from seawater, these air flows. Is introduced into the vessel 11 via the vacuuming line 7 at the top of the preliminary pump P2 and stays in the upper portion of the vessel 11. Then, the air is automatically discharged by the automatic air discharging means 12 provided at the top of the vessel 11, and the preliminary pump P
2 is held.

It is preferable that the vacuum evacuation line 7 is designed so as to have a slight upward gradient from the preliminary pump P2 toward the vessel 11 side to prevent air from staying in the evacuation line 7.

In the above-described mode, the pump P1 is normally operated, seawater is taken in, and the seawater-using plant is operated while maintaining the full state of the preliminary pump P2.

By the way, if some trouble occurs in the pump P1 during operation and the operation is stopped, the pressure in the water supply line 13 to the seawater using plant is lowered, so that the seawater using plant automatically stops its operation. Resulting in. Therefore, if the preliminary pump P2 is automatically (or manually) activated to continue the seawater supply before the pressure in the water supply line 13 is reduced, the operation stop of the seawater use plant can be prevented. When the auxiliary pump P2 is activated, the motor-operated valve 5 installed in the vacuuming line 7 at the top of the auxiliary pump P2
Is automatically closed, and the discharge pressure of the preliminary pump P2 is not applied to the evacuation line 7 and the vessel 11.

The case where one pump P1 and one auxiliary pump P2 are in operation has been described above. However, there are several pumps in operation, and one or several of them may cause some trouble. Even when the pump is stopped, the same measure (prevention of pressure drop) as described above is performed.

Incidentally, the water intake by the preliminary pump P2 is carried out in the same manner as the water intake by the pump P1 described above, and the seawater thus taken in is taken in through the suction line 2 and the delivery line 3 by another pump (not shown) in operation. It is sent to the seawater use plant together with the taken seawater.

FIG. 2 shows the above-mentioned preliminary pump P2 of the present invention.
FIG. 3 is a schematic explanatory diagram showing an example of the vessel of the present invention used in the method for maintaining full water of FIG. 2, the same reference numerals as those in FIG. 1 denote the same parts as those in FIG. In FIG. 2, the vessel 11 has a cylindrical shape, and an inlet 15 connected to the evacuation line 7 of the auxiliary pump P2 is provided on the side surface, and the evacuation line 7'of the auxiliary pump is provided at a position opposite to the inlet 15. Is provided with an outlet 16, and the inlet 15 and the outlet 16 are partitioned by a partition plate 17. As shown in FIG. 2, the partition plate 17 has a lower edge located on the bottom surface of the vessel 11 and an upper edge located above the installation position of the inlet 15.

An air outlet 18 is provided at the top of the vessel 11 described above, and in the present example, the air outlet 18 is connected to a line 20 to which a solenoid valve B-SV and a check valve 19 are attached. The line 20 is connected to the ejector 21 to which the solenoid valve A-SV is attached.
Then, these solenoid valves A-SV and B-SV are periodically opened and closed by a timer having a control circuit as shown in FIG.
Is operated by seawater sent through the open solenoid valve A-SV. These air outlets 1
8, the line 20 with the solenoid valve B-SV and the check valve 19, the ejector 21 with the solenoid valve A-SV, and the timer of FIG. 3 correspond to the automatic air discharging means 12 shown in FIG.

The vessel 11 constructed as above is
As described with reference to FIG. 1, the seawater 22 sent from the evacuation line 7 is almost filled with water. As shown in FIG. 2, the substantially full state is maintained by adjusting the set time of the timer so that the water surface is located above the upper edge of the partition plate 17.

In this state, the air mixed in the evacuation line 7 enters the vessel 11 through the inlet 15 of the vessel 11 and the flow is blocked by the partition plate 17. Since this air has a lower specific gravity than the seawater 22, it floats in the seawater 22 and stays in the upper space of the vessel 11. When the solenoid valves A-SV and B-SV are opened by the action of the timer, the air retained in the upper part of the vessel 11 is ejected by the ejector 21 operated by seawater.
The solenoid valve B is sucked into the line 20 from the air outlet 18.
-SV, Check valve 19, Ejector 21 is emitted into the atmosphere.

The check valve 19 sucks air into the vessel 11 when the solenoid valve B-SV is opened when the solenoid valve A-SV is not opened due to a failure or the like. Will be installed in.

The solenoid valves A-SV and B-SV shown in FIG.
In the control circuit shown in, the control power switch S0 is turned on.
And turn off the snap switches S1 and S2,
It opens every fixed time, for example, every 20 minutes, and the ejector 21 is driven to discharge the air in the vessel 11. Hereinafter, this operation will be described in detail in order.

When the control circuit is energized by turning on the switch S0, the address interval setting timer T1 is activated, and, for example, when 20 minutes have elapsed, the timed operation contact t1 of the address is turned on. Then, the actuating relay R1 of the solenoid valve A-SV for ejector driving water at the address is excited,
The automatic return contact r1 of the address is turned on, and the solenoid valve A-SV
Is energized and opens. When the solenoid valve A-SV opens,
Seawater for driving the ejector flows, and the ejector 21 drives.

On the other hand, the air bleed solenoid valve B-SV at the address
When the operation start setting timer T2 is excited, the timed operation contact t2 at the address is turned ON after a fixed time, for example, 8 seconds. Then, the operation relay R2 of the solenoid valve B-SV at the address is excited, the automatic return contact r2 at the address is turned on, and the solenoid valve B-SV is energized and opened. Solenoid valve B-
When the SV is opened, the air inside the vessel 11 is sucked by the ejector 21 and discharged to the outside. The timer T2 sets a fixed time, for example, 8 seconds, in order to open the air vent solenoid valve B-SV after the operation of the ejector 21.

When the air bleeding time setting timer T3 of the address is excited, the timed operation contact t of the address is reached after 2 minutes.
3 is turned off and the timer T1 is reset. When the timer T1 is reset, the contact t1 of the address becomes O.
It becomes FF, the relay R1 at the address is demagnetized, the contact r1 at the address is turned off, the energization to the solenoid valve A-SV is stopped, and the valve is closed.

At the same time, the address timer T2 is reset. As a result, the address contact t2 is turned off, the address relay R2 is demagnetized, the address contact r2 is turned off, and the solenoid valve B-SV is deenergized and the valve is closed.

At the same time, the timer T3 is reset.
As a result, the contact point t3 of the address is turned on, the timer T1 starts time counting, returns to the first operation described above, and repeats the same process as above.

When the address switch S1 is turned on, the solenoid valve A-SV can be opened arbitrarily, and when the address switch S2 is turned on, the solenoid valve B-S is arbitrarily turned on.
V can be opened.

Further, the solenoid valve AS as described above is used.
Instead of the automatic air discharging means by the V, B-SV and the timer, the automatic air discharging means by the motor-operated valves A-MV, B-MV and the electrodes E as shown in FIG. 4 can be adopted.
That is, in FIG. 4, when air stays in the upper part of the vessel 11 and the level of the seawater 22 drops from the electrode E ₃ (air bleeding completion electrode) installation position to the electrode E ₂ (air bleeding start electrode) installation position, the electrode E ₂ causes The motor-operated valves A-MV and B-MV are energized and opened, and the air in the vessel 11 is discharged to the outside by the suction force of the ejector 21 as in the case of FIG.

Seawater is introduced into the vessel 11 through the inlet 15 as the air is discharged, and the level of the seawater 22 changes to the electrode E ₃
When raised to the installation position, the motor-operated valve B is driven by the electrode E _3.
The power supply to -MV and A-MV is stopped, the valve is closed, and the air discharge is completed. This operation will be described in detail with reference to the circuit diagram of FIG.

In FIG. 4, even when the electrode E ₃ is separated from the seawater 22 due to the decrease in water level, if the electrode E ₂ is immersed in the seawater 22, the electrode E ₂ and the common electrode (electrodes E ₂ , E
₃ ) an electrode for forming an electric circuit between seawater and seawater) E ₁
Since a current flows through the resistance r between the relay R and the relay R, the relay R remains excited, but the water level further decreases and the electrode E ₂
Is separated from the seawater 22, no current flows between the electrodes E _{1 and} E ₂ , and the relay R is demagnetized.

When the relay R is demagnetized, the automatic return contact r at the address of FIG. 5 is turned on, and the relay R1 for actuating the ejector drive water electric valve A-MV at the address is excited,
The automatic return contact r1 of the address is turned on, and the motorized valve A-MV
Is opened by being energized, seawater for driving the ejector flows, and the ejector 21 is driven.

On the other hand, the air bleeding motor operated valve B-MV
When the operation start setting timer T2 is excited, the timed operation contact t2 of the address is turned on after a fixed time, for example, 8 seconds.
Then, the motor-operated valve B-MV is opened, and the air in the vessel 11 is sucked by the ejector 21 and discharged to the outside. The timer T2 is set to a fixed time, for example, 8 seconds, in order to open the electric valve B-MV for venting air after the operation of the ejector 21.

By the suction force of the ejector 21, the air inside the vessel 11 is discharged to the outside, the water level inside the vessel 11 rises, and when the electrode E ₂ is submerged in the seawater 22, the electrodes E ₁ -E through the resistance r. _{Although a} current flows between the _two , the relay R is not excited because the current is extremely small. When the water level further rises and the electrode E ₃ is immersed in the seawater 22, the electrodes E ₁ -E ₃
The relay R, in which a current flows, is excited.

When the relay R is excited, the automatic return contact r of the address is turned OFF, the operation start setting timer T2 of the electric valve B-MV at the address is reset, and at the same time, the relay for operating the electric valve A-MV at the address is reset. R1 is demagnetized, the contact r1 at the address and the timed operation contact t2 at the address are turned off, the motor-operated valves A-MV and B-MV are simultaneously closed, and the air removal by the ejector 21 is completed. The above operation is repeated by the vertical movement of the water level in the vessel 11.

As described above, the automatic air discharging means of FIG.
The air is not periodically discharged as shown in FIG. 3, but the air is not discharged at a time when the air retention amount in the vessel 11 becomes constant (in other words, when the amount of seawater 22 in the vessel 11 decreases to a constant amount). It is what is discharged.

Further, the vessel 11 of the present invention is not limited to the configuration shown in FIGS. 2 and 4, and for example, as shown in the vertical sectional views of FIGS. 6 (a) to 6 (c), The inlet 15 and the outlet 16 may be opened on the bottom surface of the vessel 10, or the outlet 16 may be provided at a position 90 ° apart from the inlet 15 as shown in the cross-sectional view of FIG. Then, as shown in the transverse sectional view of FIG.
8 may be provided on the upper side surface of the vessel 11. Furthermore,
The partition plate 17 is not limited to one having a flat surface as shown in FIGS. 2 and 4, but may be, for example, a corrugated plate as shown in the transverse sectional view of FIG. 6 (f). It may have a curved plate shape as shown in the cross-sectional view of g). Moreover, the vessel 11
The shape is not limited to the cylindrical shape as shown in FIGS. 2 and 4, and although not shown, it may be used even if the cross section has a triangular shape, a quadrangular shape, or another polygonal shape.

When the preliminary pump P2 in the flow of the embodiment shown in FIG. 1 was held using the vessel 11 of the present invention shown in FIGS. 2 to 3, the auxiliary pump P2 was operated for one month. No defective vacuuming (full water) occurred at all, and when the usage of seawater increased, pump P in operation
When the operation of No. 1 is stopped, or when the pressure of the water supply line 13 to the plant using seawater is about to drop, the auxiliary pump P2 is immediately activated, and the pressure of the water supply line 13 can be kept almost constant. It was Of course, there was no shutdown of the seawater plant.

[0046]

As described in detail above, according to the holding method of the present invention, the nearly full-filled vessel provided in the vacuum pumping line of the preliminary pump periodically discharges the air mixed in the line. Therefore, it is possible to always keep the standby pump in a water-filled state in which it can be started. Therefore, in the holding method of the present invention, the emergency start of the auxiliary pump is always possible,
It is possible to keep the pressure of water supplied to the seawater-using plant almost constant.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of a holding method of the present invention.

FIG. 2 is a schematic explanatory view showing an embodiment of the vessel of the present invention.

FIG. 3 is a diagram showing an example of a timer control circuit as an example of an automatic air discharging means in the vessel of the present invention.

FIG. 4 is a diagram for explaining an example of an installation mode of electrodes as another example of the automatic air discharging means in the vessel of the present invention and its operation.

5 is a diagram showing an example of a control circuit in the automatic air discharging means of FIG.

FIG. 6 is a schematic explanatory view showing another embodiment of the vessel of the present invention, in which (a) to (c) and (e) are longitudinal sectional views, (d),
(F), (g) is a cross-sectional view.

[Explanation of symbols]

P1 Pump in operation P2 Preliminary pump 2,2 'Suction line 11 Vessel 12 Automatic air discharge means 15 Vessel inlet connected to vacuum line 16 Vessel outlet 17 connected to vacuum line 17 Partition plate 18 Air discharge port 19 Check valve 20 Air discharge line 21 Ejector 22 Vessel full water A-SV, B-SV solenoid valve A-MV, B-MV electric valve

Claims (2)

[Claims] 1. A vessel that is almost full of water is provided on the way of a vacuuming line from the top of the pump body of the auxiliary pump,
A method for holding a preliminary pump, characterized in that the air accumulated in the upper part of the vessel is automatically discharged. 2. The vessel according to claim 1, wherein an inlet and an outlet connected to a vacuuming line of a preliminary pump are provided at appropriate separate positions on a side surface or a bottom surface of the vessel, and the inlet is provided. A partition plate that divides the partition part from the outlet part is provided such that the lower edge of the partition plate is located on the bottom surface of the vessel and the upper edge is located above the inlet, and the air is automatically discharged to the upper part of the vessel. A vessel provided with means.