KR101540289B1 - Recirculation valve and pumping system including the same - Google Patents

Abstract

A recirculation valve and a pumping system including the same are disclosed. The recirculation valve according to an embodiment of the present invention includes a valve body having an inlet through which fluid flows and an outlet through which fluid flows, a pilot line branched from one surface of the valve body to distribute the pressure of the fluid, And a stem unit that opens or closes the flow of fluid flowing from the inlet to the outlet in accordance with the pressure bases of the fluid.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a recirculation valve and a pumping system including the recirculation valve.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recirculation valve and a pumping system having the recirculation valve, and more particularly, to a recirculation valve and a pumping system having the recirculation valve that transfer the fluid stored in the suction tank to a destination.

Generally, a pump is used to pressurize a fluid to be transferred from a suction tank in which a fluid such as a ship or an offshore plant is stored.

However, in order to transfer all the fluid stored in the suction tank, it is not possible to simply operate the pump.

This is due to the characteristics of a centrifugal pump which is commonly used. In the case of a centrifugal pump, NPSHr (Net Positive Suction Head required) and the minimum head (pressure) required at the inflow end of the pump must be satisfied. I can drive.

That is, if the NPSHa (Net Positive Suction Head available) value is at least NPSHr + 0.6m (or NPSHr × 1.3) at the suction line where the fluid is sucked, the pump can operate properly.

For reference, the head refers to the height at which the pump draws water, and NPSH (Net Positive Suction Head) is a measure of the likelihood of cavitation of the pump.

Cavitation refers to the generation of bubbles when the pressure falls below a saturated vapor pressure due to a high suction head or a locally high velocity part in the pump.

When cavitation occurs, noise and vibration are generated in the initial stage of pressure drop, and the performance of the pump is deteriorated.

NPSHr means the local pressure drop within the pump and is determined by the manufacturer of the pump.

NPSHa means the degree of safety for cavitation and is determined by the installation conditions of the pump, such as the distance between the water surface and the pump, the length of the intake pipe and the length of the pipe, the type and temperature of the transfer liquid.

That is, the value of NPSHa is greatly influenced by the water level of the suction tank and the pressure drop of the suction line. When the pumping flow rate is constant, the value of NPSHa is determined according to the suction tank, The lower the value, the lower the NPSHa value.

Therefore, it is impossible to pump simply by driving the pump below a certain level.

As the pumping flow decreases, the NPSHa increases and the NPSHr decreases. Therefore, if the pumping flow rate is reduced, it is possible to operate while satisfying the NPSH condition.

However, since all pumps have an acceptable minimum flow rate (usually 30% of the normal flow rate), it is impossible to operate by reducing the infinite flow rate.

In addition, various sensors (sensors) and controllers are required to control the flow rate to a certain level.

Accordingly, the pumping flow rate is very small, but is applied to discharge all of the fluid from the suction tank 20 by adding a small stripping pump or an eductor having no limit to NPSH or the like.

However, when the eductor or the stripping pump is additionally operated, the capacity is very small as compared with the main pump which mainly transports the fluid from the suction tank, so that the operation time is long.

For example, in a ballast system of a ship, it takes a long time to extract all of the fluid from the suction tank, since more than half of the time taken to extract the fluid from the suction tank is the operation time of the stripping pump.

Therefore, it is necessary to pump the main pump to a lower level for a longer time than before to minimize the running time of the eductor or the stripping pump.

Korean Patent No. 10-1001774 (Announcement of Dec. 15, 2010)

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a recirculation valve that reduces the time spent in discharging all of the fluid from the suction tank by reducing the flow rate in the suction tank and operating the main pump for a longer time than before, Pumping system.

According to an aspect of the present invention, there is provided a valve apparatus comprising: a valve body having an inlet through which a fluid flows and an outlet through which the fluid flows; A pilot line branched from one surface of the valve body to distribute the pressure of the fluid; And a stem unit that opens or closes the flow of fluid flowing from the inlet to the outlet in accordance with a pressure basis of the fluid dispensed by the pilot line.

Wherein the stem unit comprises: a stem unit body part which is distributed by the pilot line and opens and closes the flow of the fluid by rising and falling with respect to the valve body by the pressure of the fluid; And a stem unit lifting unit installed on the valve body to raise or lower the stem unit body.

The stem unit elevating unit includes a stem unit pressure spring provided inside the valve body and elastically biasing the stem unit body downward so that the stem unit body blocks the flow of the fluid. And a stem unit speed reducing unit that alleviates the speed of the stem unit body when the stem unit body is lifted by the pressure of the fluid, which is distributed by the pilot line.

Wherein the stem unit speed reducing unit includes a plurality of stem unit protrusions having a protruding shape protruding from an outer surface of the stem unit body and provided adjacent to each other to buffer the speed of the stem unit body stepwise when the stem unit body is lifted up; And a stem unit stopper provided on the valve body and engaged with the stem unit protrusion to stop the stem unit body.

The stem unit stopper may include: a stem unit fixing spring having elasticity coupled to the valve body; And a stem unit fixing pin coupled to the stem unit fixing spring and hooked to the stem unit protrusion.

Wherein the stem unit elevating portion further includes a stem unit stopper provided on the valve body to limit a descending range of the stem unit body portion, wherein the stem unit body portion includes a stem unit flange As shown in FIG.

And the lower end of the stem unit body may have a cage shape capable of partially accommodating the fluid when the fluid flows out.

The valve body includes a body body having a hollow shape and accommodating the stem unit body portion and the stem unit lift portion; And a conduit connecting body disposed laterally to the body and coupled to the body and connected to a conduit through which the fluid passes.

Wherein the channel connecting body includes a blocking wall provided inside the body body so as to be inclined with respect to the center axis of the body body and blocking the flow of the fluid passing through the channel connecting body; And a fluid inlet hole formed through the center of the blocking wall and through which the fluid passes.

According to another aspect of the present invention, there is provided a suction apparatus comprising: a suction tank in which a fluid to be transferred is stored; A pipe connected to the suction tank for transferring the fluid from the suction tank; A main pump provided on the pipe to apply pressure to the fluid; A recirculation line connected to the front side and rear side pipes of the main pump; And a recirculation valve provided in the recirculation line for regulating the flow rate according to a predetermined set pressure.

According to the present invention, since the flow rate in the suction tank is reduced and the main pump is operated for a longer time than the conventional one, the time consumed for discharging all of the fluid from the suction tank can be reduced.

1 is a cross-sectional view of a recirculation valve according to an embodiment of the present invention.
2 is a cross-sectional view illustrating the operation of the recirculation valve of FIG.
3 is an enlarged cross-sectional view of the stem unit speed reducing part shown in Fig.
4 is a configuration diagram of a pumping system having the recirculation valve of FIG.
5 is another configuration diagram of a pumping system having the recirculation valve of FIG.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

FIG. 1 is a sectional view showing a recirculation valve according to an embodiment of the present invention, FIG. 2 is a sectional view showing the operation of the recirculation valve in FIG. 1, FIG. 3 is an enlarged sectional view of the stern unit speed- FIG. 4 is a configuration diagram of the pumping system having the recirculation valve of FIG. 1, and FIG. 5 is another configuration diagram of the pumping system having the recirculation valve of FIG.

Hereinafter, the construction and operation of the recirculation valve 10 will be described first, and the construction and operation of the pumping system 1 will be described later.

1 to 3, a recirculation valve 10 according to an embodiment of the present invention includes a valve body 100, a pilot line 200, and a stem unit 300.

First, the valve body 100 is provided with an inlet I and an outlet E through which fluid flows in and out.

The valve body 100 includes a body 110 and a pipe connecting body 120.

The body 110 has a hollow shape and functions to receive a stem unit body 310 and a stem unit lifting unit 320, which will be described later.

The pipe connecting body 120 is disposed laterally with the body 110 and is coupled to the body 110 and is connected to a channel through which the fluid passes.

The pipe connecting body 120 further includes a blocking wall 121 and a fluid inlet / outlet hole 122.

The blocking wall 121 is sloped with respect to the central axis of the body 110 and serves to cut off the flow of the passing fluid.

The fluid inlet / outlet hole 122 is formed at the center of the blocking wall 121 and is provided with a hole through which the fluid can pass when the stem unit body 310 rises.

In the embodiment of the present invention, the shape of the valve body 100 has the shape of a globe type as shown in the figure, but it may also have the shape of a flattened gate valve or other various valve shapes have.

Therefore, it is to be understood that the scope of the present invention is not limited by the shape of the valve body 100.

Next, the pilot line 200 branches from one surface of the valve body 100 and distributes the pressure of the fluid.

In the embodiment of the present invention, the pilot line 200 is connected to the outlet E as shown in the figure, but the pilot line 200 is connected to the suction side of the main pump 40 It is obvious that the scope of the present invention is not limited thereto since it may be directly connected to the main pump 40 or may be connected to other places that distribute the suction side pressure of the main pump 40. [

When the pressure of the outlet E is reduced, the pilot line 200 is connected to the body 110, so that the pressure inside the body 110 also decreases, so that the pressure of the fluid is distributed.

On the other hand, the stem unit 300 serves to open and shut off the flow of the fluid flowing from the inlet I to the outlet E, based on the pressure of the fluid, which is distributed by the pilot line 200.

The stem unit 300 includes a stem unit body 310 and a stem unit lifting unit 320.

First, the stem unit body 310 moves up and down with respect to the valve body 100 by the pressure of the fluid, which is distributed by the pilot line 200, to open and shut off the flow of the fluid.

The stem unit body 310 further includes a stem unit flange 311 which is caught by the stem unit stopper 325 to be described later and is restricted from falling.

For reference, the upward and downward directions in the present embodiment are defined as a rise when the valve body 100 is moved upwards with respect to the inner center of the valve body 100, and the downward movement is defined as a downward movement.

Therefore, it will be appreciated that when the recirculation valve 10 is installed at a vertical, horizontal or other angle depending on the installation environment, the directions of the upward and downward directions may be changed.

Next, the stem unit lifting unit 320 is installed on the valve body 100 and serves to raise or lower the stem unit body 310.

2, the stem unit elevating portion 320 includes a stem unit urging spring 321 and a stem unit speed reducing portion 322. As shown in FIG.

First, the stem unit pressure spring 321 is provided inside the valve body 100.

The stem unit pressure spring 321 elastically biases the stem unit body 310 downward so as to block the flow of fluid through the stem unit body 310.

Therefore, an adjustment screw (not shown) can be further added to the stem unit pressure spring 321 to adjust the elastic force and the set pressure of the stem unit pressure spring 321.

Next, the stem unit speed reducing unit 322 causes the stem unit body portion 310 to rise as the stem unit body portion 310 is lifted by the pressure of the fluid distributed by the pilot line 200 It serves to slow down the speed.

3, the stem unit speed mitigation section 322 includes a plurality of stem unit protrusions 323 and a stem unit stop section 324. [

First, the plurality of stem unit protrusions 323 have a protruding shape protruding from the outer surface of the stem unit body 310.

The plurality of stem unit protrusions 323 are provided adjacent to each other so as to buffer the speed stepwise when the stem unit body 310 rises.

In this case, when the fluid inlet / outlet hole 122 is opened, the size of the shape of the plurality of protrusions is such that, as shown in the figure for the sake of fine control, .

However, the size of the shape of the plurality of protrusions may be the same or larger in size and may have various shapes, so that the scope of the present invention is not limited thereto.

The stem unit stopper 324 is provided on the valve body 100 and is engaged with the stem unit protrusion 323 to stop the stem unit body 310. [

In more detail, the stem unit stopper 324 includes a stem unit fixing spring 324a and a stem unit fixing pin 324b.

First, the stem unit fixing spring 324a is a spring that is coupled to the valve body 100 and has elasticity.

The stem unit fixing spring 324a serves to support the impact when the stem unit fixing pin 324b is hooked.

In this case, the stem unit fixing spring 324a may have an example of a leaf spring as shown in the figure, but a spring having a different elasticity may also be applied, so that the present invention is not limited thereto .

The stem unit fixing pin 324b is coupled to the stem unit fixing spring 324a and is engaged with the stem unit protrusion 323.

Therefore, in order to prevent the stem unit body 310 from rising at an abrupt speed, the stem unit fixing pin 324b is hooked to the stem unit protrusion 323 since the speed should be relaxed at the middle.

Hereinafter, the operation of the recirculation valve 10 according to an embodiment of the present invention will be described.

First, when the pressure of the outlet E drops, the internal pressure of the pilot line 200 connected to the outlet E also drops.

When the pressure inside the pilot line 200 drops, the pressure of the body 110 connected to the pilot line 200 also becomes low.

Therefore, the stem unit body 310 rises due to the lowered pressure of the body 110.

When the stem unit body 310 rises, the stem unit pressure spring 321 connected to the stem unit body 310 is compressed.

In this case, when the stem unit body 310 rises, a plurality of stem unit protrusions 323 are provided so as to prevent a sharp rise and to buffer a stepwise rising speed, And the rising speed is relaxed.

Then, the stem unit main body 310 is stopped by the engagement by the stem unit fixing pin 324b coupled to the stem unit fixing spring 324a.

If the stem unit body 310 is to be lowered, it is necessary to limit the descending range in order to prevent collision between the stem unit body 310 and the valve body 100.

Therefore, a stem unit flange 311 is provided at the upper part of the stem unit body 310.

The stem unit unit flange 311 is caught by the latching jaw of the stem unit stopper 325 so that the movement of the stem unit body 310 is restricted.

Hereinafter, the configuration of the pumping system 1 having the recirculation valve 10 according to the embodiment of the present invention will be described first, and the operation thereof will be described.

4, the pumping system 1 includes a suction tank 20, a pipe 30, a main pump 40, a recirculation line 50, and a recirculation valve 10.

First, the suction tank 20 is provided in a ship and an offshore plant, and is a place where the fluid to be transferred is stored.

The pipe 30 is connected to the suction tank 20 and serves to transfer the fluid to a place where the fluid is discharged from the suction tank 20.

The main pump 40 is provided in the pipe 30 and serves to apply pressure to transfer the fluid.

In other words, in the embodiment of the present invention, the main pump 40 mainly refers to a pump which is used as a pump having a larger discharge flow rate and performance than an eductor or a stripping pump. However, the present invention is not limited thereto.

The recirculation line 50 is connected to the front and rear piping 30 of the main pump 40 to allow fluid to flow in and out of the recirculation valve 10.

In the embodiment of the present invention, the front side means that the fluid to be transferred does not yet pass through the main pump 40, and the rear side means that the fluid to be transferred passes through the main pump 40.

As described above, the recirculation valve 10 is provided in the recirculation line 50 and functions to regulate the flow rate according to a preset hydraulic pressure to open and close.

Hereinafter, the operation of the pumping system 1 having the recirculation valve 10 according to the embodiment of the present invention will be described.

When the fluid to be transferred stored in the suction tank 20 is continuously discharged using the main pump 40, the water level of the suction tank 20 decreases.

When the water level of the suction tank 20 is continuously decreased, the flow rate to be fed to the main pump 40 is reduced to a certain level or less.

As the flow rate to be delivered to the main pump 40 decreases, the minimum head NPSHr required in the front side pipe 30 of the main pump 40 decreases.

The pressure in the front side piping 30 of the main pump 40 is reduced to reach a set constant pressure.

At this time, the fluid inlet / outlet hole 121 starts to be opened by the operation of the recirculation valve 10, which is one embodiment of the present invention described above.

When the fluid inlet / outlet hole 121 is opened, the flow rate of the fluid recirculating from the inlet I to the outlet E starts to be formed.

Then the flow rate that is recirculated from the inlet I to the outlet E in the front side pipe 30 of the main pump 40 joins the flow rate which is substantially continuously pumped from the suction tank 20, As a result, the main pump 40 flows a certain amount or more of the flow rate.

Thus, the main pump 40 maintains a constant pressure in the front-side pipe 30, and the water level of the suction tank 20 continuously decreases.

When the opening of the fluid inlet / outlet hole 122 of the recirculation valve 10 is continuously increased, the recirculation flow rate through the recirculation valve 10 is continuously increased.

Therefore, even if the water level of the suction tank 20 is reduced, the main pump 40 continuously replenishes the recirculating flow rate passing through the recirculation valve 10, The main pump 40 can be used as much as possible.

That is, according to the embodiment of the present invention, even if the flow rate in the suction tank 20 continuously decreases, the flow rate is automatically and continuously replenished through the recirculation line 50 and the recirculation valve 10, The main pump 40 having a large discharge flow rate during the operation time required to empty the fluid in the suction tank 20 is utilized as much as possible.

Therefore, unlike the conventional technique, the time for using the ejector (not shown) or the stripping pump (not shown) having a small discharge capacity is minimized, and the operation time required for discharging the fluid to be transferred from the suction tank 20 There is an advantage that it can be reduced.

Although not shown in the drawings, if the pumping system 1 is constructed by providing a plurality of recirculation valves 10 with different set pressures, various recirculating flow rates may be adjusted and operated.

5, the pilot line 200 for distributing the pressure of the fluid is connected to the outlet E of the recirculation valve 10 in the case of the configuration diagram of another pumping system 1a according to an embodiment of the present invention, Side piping of the main pump 40 so that the pressure on the suction side of the main pump 40 can be sensed immediately.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Accordingly, such modifications or variations are intended to fall within the scope of the appended claims.

10: recirculation valve 20: suction tank
30: piping 40: main pump
50: recirculation line 100: valve body
110: body body 120: pipe connecting body
200: Pilot line 300: Stem unit
310: stem unit body part 320: stem unit lift part
1: Pumping system

Claims (10)

A valve body having an inlet through which the fluid flows and an outlet through which the fluid flows;
A pilot line branched from one surface of the valve body to distribute the pressure of the fluid; And
And a stem unit that opens or closes the flow of fluid flowing from the inlet to the outlet in accordance with a pressure basis of the fluid dispensed by the pilot line,
The stem unit comprises:
A stem unit body portion that is divided by the pilot line and opens and closes the flow of the fluid by rising and falling with respect to the valve body by the pressure of the fluid; And
And a stem unit lifting unit installed on the valve body to lift or lower the stem unit body,
The stem unit elevating unit includes:
And a stem unit stopper provided on the valve body to limit a downward extent of the stem unit body,
The stem unit main body portion
And a stem unit flange which is caught by the stem unit stopper and is restricted from falling down. delete The method according to claim 1,
The stem unit elevating unit includes:
A stem unit pressure spring provided inside the valve body for elastically biasing the stem unit body downward so that the stem unit body blocks the flow of the fluid; And
And a stem unit speed relieving portion which is distributed by the pilot line and relaxes the speed of the stem unit body portion when the stem unit body portion is lifted by the pressure of the fluid. The method of claim 3,
The stem unit speed reducing unit may include:
A plurality of stem unit protrusions each having a protruding shape protruding from an outer surface of the stem unit body and provided adjacent to each other to buffer the speed of the stem unit body step by step; And
And a stem unit stopper provided at the valve body and engaged with the stem unit protrusion to stop the stem unit body. 5. The method of claim 4,
The stem unit stopper may include: a stem unit fixing spring having elasticity coupled to the valve body; And
And a stem unit fixing pin coupled to the stem unit fixing spring and engaged with the stem unit protrusion. delete The method according to claim 1,
Wherein a lower end of the stem unit body is in the shape of a cage capable of partially accommodating the fluid at the time of the outflow of the fluid. The method according to claim 1,
Wherein the valve body comprises:
A body body having a hollow shape and housing the stem unit body and the stem unit lift portion; And
And a conduit connecting body disposed laterally to the body body and coupled to the body body, the conduit connecting body being connected to a conduit through which the fluid passes. 9. The method of claim 8,
The pipe connecting body includes:
A blocking wall provided inside the body body so as to be inclined with respect to the center axis of the body body and blocking the flow of the fluid passing therethrough; And
And a fluid inlet and outlet hole passing through the center of the blocking wall and through which the fluid passes. A suction tank in which a fluid to be transferred is stored;
A pipe connected to the suction tank for transferring the fluid from the suction tank;
A main pump provided on the pipe to apply pressure to the fluid;
A recirculation line connected to the front side and rear side pipes of the main pump; And
And a recirculation valve according to any one of Claims 1 to 7, and a recirculation valve according to any one of Claims 3 to 5, which is provided in the recirculation line and adjusts the flow rate according to a predetermined set pressure.

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