JPS6056279B2 - liquid dredging equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for dredging residual liquid in a liquid tank.

Conventional devices of this type include a gas-liquid separation tank provided between a liquid tank and its main pump, and a jet pump operated using a portion of the liquid discharged from the main pump to separate the gas and liquid. There are types that are installed between the tank and the liquid tank, and types that have a gas-liquid separation tank that is installed between the liquid tank and its main pump, and a gas release tank. There is a problem with durability because the valve for starting and stopping the jet pump is operated frequently during steep cutting work, and there is also a drawback that air is sucked into the main pump. There is a problem in that it requires a large-scale device to separate the gases, making the structure complicated.

The present invention aims to solve the above-mentioned problems in conventional liquid dredging equipment, and provides a jet pump that can be used continuously after dredging work begins, and a jet pump that can be started and stopped for gas-liquid separation. The object of the present invention is to provide a device that can dredge liquid efficiently and reliably by combining a repeatable vacuum pump and automating them.

For this reason, the liquid dredging device of the present invention includes an auxiliary tank connected to a liquid tank via a main suction pipe, a main suction pipe valve provided on the main suction pipe, and a suction dredge that bypasses the main suction pipe valve. A jet pump disposed in the main suction pipe together with the main pipe valve, a main pump connected to the auxiliary tank, and a discharge liquid of the main pump so that a part of the liquid discharged from the main pump becomes the driving liquid for the jet pump. The main suction pipe is equipped with a communication pipe with a driving liquid valve that connects the jet pump to the jet pump, and a liquid level detector for the auxiliary tank. an electromagnetic valve control unit capable of closing a valve to open the suction dredging main pipe valve and also opening the driving fluid valve; It is characterized by being equipped with a vacuum pump that can bleed air from the top of the auxiliary tank. Hereinafter, an embodiment in which the present invention is applied to a tanker will be explained with reference to the drawings.
An auxiliary tank 3 is connected to the auxiliary tank 3 via a main suction pipe 2a having a main pump 2a, and a main pump 4 is connected to the auxiliary tank 3. A communication pipe 8 with a drive fluid valve 7 is provided in the discharge portion 5a in front of the discharge valve 5 connected to the main pump 4, and branches from the discharge portion 5a to reach the jet pump 6.

The jet pump 6 is arranged in the suction main pipe 2a together with the suction dredging main pipe valve 9 so as to be able to bypass the suction main pipe valve 2,
When starting the dredging work of the liquid tank 1, the suction main pipe valve 2 is closed and the suction dredging main pipe valve 9 is opened by a valve control means, which will be described later.

The auxiliary tank 3 is provided with a liquid level detector 10, and a converter 11 converts the signal from the liquid level detector 10 into power.
and a power unit 12a connected to this converter 11.
A solenoid valve control unit 12 is provided.

This electromagnetic valve control unit 12 closes the main suction pipe valve 2 based on a signal from the liquid level detector 10 when the liquid level in the auxiliary tank 3 begins to drop and starts dredging the liquid tank 1. The driving fluid valve 7 is opened at the same time as the main pipe valve 9 is opened.

In addition, at that time, the electromagnetic valve control unit 12 controls the discharge valve 5.
The opening/closing control is performed.

Further, an air bleed pipe 13 is provided which communicates from the upper part of the auxiliary tank 3 to the upper part of the liquid tank 1, and this air bleed pipe 13 has the following features:
A vacuum pump 14 and stop valves 15 and 16 before and after the vacuum pump 14 are inserted. When the liquid level in the auxiliary tank 3 decreases, the converter 11 is activated by a signal from the liquid level detector 10, and the vacuum pump 14 is accordingly activated and each stop valve 15, 16 is opened. , the gas in the auxiliary tank 3 is released into the upper part of the liquid tank 1.
In the figure, reference numeral 17 indicates a bell mouth, 18 indicates a suction branch pipe with a valve, 19 indicates a strainer, and 20 indicates a rectifying plate.

Further, reference numeral 21 indicates an upper deck, 22 indicates a bottom outer plate, 23 indicates a tank bulkhead, and 24 indicates a pump room.

Since the liquid dredging device of the present invention is configured as described above, when unloading the liquid tank 1, the bell mouth 1 is usually
The liquid sucked from 7 passes through the main suction pipe valve 2 of the main suction pipe 2a.
The gas enters the auxiliary tank 3 through the main pump 4 and is discharged from the discharge valve 5. However, when the liquid level in the liquid tank 1 falls below a certain level, gas starts to be sucked in from the bell mouth 17. As this gas enters the auxiliary tank 3, the amount of gas in the auxiliary tank 3 increases, and when the liquid level in the auxiliary tank 3 drops to a predetermined value, it is detected by the liquid level detector 10. The signal activates the converter 11 and the electromagnetic valve control unit 12 with the power unit 12a.

As a result, the opening degree of the discharge valve 5 is controlled, and the driving fluid valve 7
The main suction pipe valve 9 is opened, and the main suction pipe valve 2 is closed.

Therefore, a part of the pumped liquid reaches the jet pump 6 via the drive liquid valve 7, which activates the jet pump 6 to dredge the liquid or gas-liquid mixture in the liquid tank l. It will be done.

At the same time, the vacuum pump 14 equipped to promote the dredging efficiency of the jet pump 6 is also started, and the stop valves 15 and 16 before and after it are opened.

Thereafter, when the liquid level in the auxiliary tank 3 recovers to a certain set value, the vacuum pump 14 is stopped and the stop valves 15 and 16 are closed. Thereafter, the vacuum pump 14 is turned on and off and the stop valves 15 and 16 are opened and closed repeatedly in response to fluctuations in the liquid level in the auxiliary tank 3.

However, since the driving liquid valve 7 and the main suction pipe valve 9 are kept open, and the main suction pipe valve 2 is kept closed,
Continuous dredging work is carried out.

When this steepening work is nearing completion and the liquid level in the auxiliary tank 3 remains low for a certain period of time and does not recover, the main pump 4 is tripped. The gas extracted by the vacuum pump 14 is returned to the upper part of the liquid tank 1 or released into the atmosphere.

When this gas is returned to the liquid tank 1, the rectifier plate 20 can prevent the generation of static electricity. The main function of this device is dredging by the jet pump 6, and active extraction by the vacuum pump 14 serves as an auxiliary function, but if the jet pump 6 fails, dredging by the vacuum pump 14 is also possible. Yes, and conversely, vacuum pump 14
Even if the jet pump 6 breaks down, dredging can be performed only by the jet pump 6.

In this way, the liquid dredging device of the present invention can suck up to the limit of the open end of the bell mouth 17, and not only can it exhibit good liquid dredging efficiency, but also
A significant increase in suction volume is provided, and the vacuum pump 14
Due to the positive air bleed action, the amount of driving liquid for the jet pump 6 can be reduced, and the main pump 4 is prevented from sucking air, resulting in the effect of improving cargo lifting efficiency.

When a flammable liquid is stored in the liquid tank 1, the liquid level detector 10 sends an air signal to the converter 11 for explosion protection.
This converter 11 converts the air signal into an electrical signal and sends this to the electromagnetic valve control unit 12. Also,
The suction main pipe valve 2, the discharge valve 5, the driving liquid valve 7, and the suction dredging main pipe valve 9 are controlled by hydraulic pressure or pneumatic pressure.

Further, the stop valves 15 and 16 are also controlled by air signals for explosion protection.

The present invention is not limited to the above-mentioned cargo tanks, but can also be applied to ballast tanks of cargo ships, and can also be applied to unloading systems for land tanks.

[Brief explanation of the drawing]

The figure is an explanatory diagram showing a liquid dredging device as an embodiment of the present invention. 1...Liquid tank, 2...Suction main pipe valve, 2a...
Main suction pipe, 3... Auxiliary tank, 4... Main pump, 5
...Discharge valve, 5a...Discharge part, 6...Jet pump, 7...Drive liquid valve, 8...Connection pipe, 9...Suction dredging main pipe valve, 10...Liquid position detector, 11... converter, 12... electromagnetic valve control unit, 12a... power unit, 13... bleed pipe, 14... vacuum pump, 15, 16... stop valve, 17...Bellmouth,
18...Suction branch pipe with valve, 19...Strainer, 20
... rectifier plate, 21 ... upper deck, 22 ... bottom outer plate, 23 ... tank bulkhead, 24 ... pump room.

Claims (1)

[Claims] 1. An auxiliary tank connected to the liquid tank via a main suction pipe, a main suction pipe valve provided on the main suction pipe, and a main suction pipe valve arranged in the main suction pipe together with a main suction dredging valve so as to be able to bypass the main suction pipe valve. a jet pump connected to the auxiliary tank, and a driving liquid valve that connects a discharge part of the main pump to the jet pump so that a part of the liquid discharged from the main pump is used as driving liquid for the jet pump. Equipped with a connecting pipe and a liquid level detector for the auxiliary tank,
an electromagnetic valve control unit capable of closing the suction main pipe valve, opening the suction dredging main pipe valve, and opening the driving liquid valve according to a signal from the liquid level detector when starting dredging work of the liquid tank; A liquid dredging device characterized in that a vacuum pump is provided which is activated by a signal from the liquid level detector to bleed air from the upper part of the auxiliary tank in response to a decrease in the liquid level of the auxiliary tank.