JPH0618152Y2 - Fluid discharge device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a fluid discharge device for a tank truck that stores and transports a fluid such as a liquefied gas, and in particular, a manhole is provided at the bottom of the tank and The present invention relates to improvement of a fluid discharge device configured to mount a submersible canned motor pump.

[Conventional technology]

Conventionally, liquefied petroleum gas (LPG), liquefied natural gas (LN)
As a fluid discharge device to be mounted on a tank truck that stores and transports a liquefied gas fluid such as G), a general-purpose motor pump is installed outside the tank, or a submersible canned motor pump is installed from the manhole on the tank to the tank. It is general to adopt a configuration in which the device is suspended inside and installed.

For example, as shown in FIG. 1, in a model in which a conventional general-purpose motor pump is used for a tank truck, a drainage piping system 12 is led out from a bottom portion 11 of the tank 10 and is connected to the outside of the tank 10. It is connected to the general-purpose motor-pump 14 arranged in the above. In this case, since the installation space for the pump and the piping system is required near the lower part of the tank, the tank capacity is restricted, and the possibility of leaking the liquefied gas increases due to the lengthening of the piping system. In addition, there is a great risk of damage to the piping system and pump due to a traffic accident, and since the emergency shutoff valve 16 is installed on the pump suction side, this becomes a resistance and the suction side when the liquid level in the tank becomes low. As a result, gas is likely to be generated, and it is impossible to discharge all the liquid in the tank. Further, the drive motor of the pump is provided with an external terminal box to be connected to the drive power source, which has a complicated facility configuration and the maintenance work is remarkably troublesome due to the dispersion of maintenance points.

From this point of view, the present applicant previously provided an opening at the bottom of a tank for storing a fluid such as a liquefied gas, and attached a lid plate to this opening in a liquid-tight and detachable manner, and An immersion type pump device is attached to the inside, that is, a portion facing the inside of the tank, and a housing capable of hermetically surrounding the pump device is fixedly provided inside the opening of the tank, and a part of the housing is opened and closed between the inside and the outside A fluid discharge device having an externally operable valve device for free communication and means for supplying an incombustible gas into the housing from the outside has been developed, and a patent application has been filed. 5
6-29093).

The fluid discharge device configured as described above is configured such that the housing is hermetically closed, the interior is filled with a nonflammable gas to expel all the liquefied gas, the pump piping system is shut off and separated, and then the lid plate is removed. With a simple structure, it is possible to reliably prevent the liquefied gas from leaking out and to easily perform maintenance work on the pump.

[Problems to be solved by the device]

However, the fluid discharge device according to the patent application, by providing the immersion type pump device in the bottom of the tank, it is possible to simplify the piping system and prevent the risk of leakage of liquefied gas, but the bottom of the tank. The structure for attaching the pump device to the lid body that is detachably attached to the opening provided in is complicated, and in particular, in order to simplify the maintenance work of the pump, a structure for hermetically surrounding the pump device is also provided. As the structure is added and the structure becomes more complicated, the terminal box for connecting to the external power supply is installed outside the cover plate, so not only the piping configuration of the conductor wire inside the cover plate is required, With regard to the installation of the emergency shutoff valve, it was difficult to set the pump pipe at an appropriate position due to its configuration, and there were many practical difficulties.

Therefore, an object of the present invention is to install a submersible canned motor pump in the lower part of a tank truck to connect a power cable so that the structure can be simplified and the airtightness can be improved without restricting the tank capacity. With the configuration that requires almost no maintenance of the pump, there is little risk of leakage of liquefied gas etc. from the discharge piping system, and its damage and influence are minimized even in the unforeseen situation such as a traffic accident. With a strong structure that can suppress it, and when discharging the liquefied gas, lowering the position of the pump suction side from the bottom of the tank, it is possible to eliminate residual liquid in the tank and realize efficient pump operation. The emergency shutoff valve can be installed properly and easily so that it does not hinder the discharge of liquid in the tank. To provide a fluid discharge device for tank truck for.

[Means for Solving the Problems]

The fluid discharge device according to the present invention is provided with a manhole at the bottom of a tank truck for storing and transporting a liquid such as liquefied gas, and a lid chamber for communicating with the inside of the tank. The pump casing of the submersible canned motor pump is loaded into the container, the pump inlet is exposed to the bottom of the liquid storage chamber, and the pump casing is formed integrally with the lid so as to be positioned sufficiently lower than the bottom of the tank. In the fluid discharge device configured to discharge a fluid inside the tank through the liquid storage chamber by providing a discharge port communicating with the discharge portion of the pump casing in a part of the cover body, Provide an emergency shutoff device at the discharge port of the pump casing provided in the section with the emergency shutoff valve of this emergency shutoff device inserted in the discharge port side space in the pump casing. Is characterized by.

[Action]

According to the fluid discharge device of the present invention, the lid of the manhole is provided with the liquid storage chamber communicating with the inside of the tank, and the pump casing of the submersible canned motor pump is loaded in the liquid storage chamber and the pump suction port is provided. Face the bottom of the liquid reservoir,
The pump casing is integrally formed with the lid so as to be located at a position sufficiently lower than the bottom of the tank, and a discharge port communicating with the discharge portion of the pump casing is provided in a part of the lid to prevent the fluid inside the tank from flowing. By constructing the submersible canned motor pump to be discharged through the liquid storage chamber, the submersible canned motor pump can be firmly and easily attached to the lid, and can be configured to have excellent airtightness. The terminal chamber is provided adjacent to the liquid storage chamber of the casing, and the conducting wire led out from the motor section is guided to the terminal chamber through the lid through the tea pipe and the wiring pipe. By configuring to connect with the power cable, the piping configuration of the conductor wire can be simplified and the connection work with the power cable can be facilitated. By installing an emergency shutoff device at the discharge port of the pump casing with the emergency shutoff valve of this emergency shutoff device inserted in the space on the discharge port side in the pump casing, the liquid in the tank can be discharged smoothly. Efficient pump operation can be realized by eliminating the residual liquid in the tank.

〔Example〕

A preferred embodiment of the fluid discharge device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 is a tank 1 of a tank truck for storing and carrying a fluid such as liquefied gas to which the fluid discharge device according to the present invention is applied.
8 is shown. However, a manhole 20 is provided at the bottom of the tank 18, and a pump casing 22 with a flange integrally formed with the manhole cover is fixed to the manhole 20 in a liquid-tight manner via a sealing member such as a gasket.

That is, as shown in FIG. 3, the pump casing 22
Is also a manhole cover and is made of a metal material suitable for the type of liquid to be loaded on the tank truck.
A flange portion 24 is provided around the outer edge portion of the pump casing 22, and the flange portion 24 is liquid-tightly fixed to the manhole 20 by a stud bolt 28 via a gasket 26.

On the end surface of the pump casing 22, the motor section 30 of the submersible canned motor pump is mounted in a liquid-tight manner via a mounting bolt 34 by a flange section 32 extending to the end section.

The motor shaft 36 of the motor unit 30 is connected to the pump casing 22.
An inducer 38 and an impeller 40 are axially attached to the tip end of the extender 38.

The lead wire 42 led out from the motor portion 30 passes through the inside of the tea pipe 44 and is guided into the connection terminal chamber 46 provided in the hollow portion of the pump casing 22. The conductor 42 is completely insulated from the stator 48 of the motor unit 30 to the inside of the tee pipe 44 by resin filling or the like for explosion protection. Further, by connecting the terminal of the lead wire 42 to the external power supply cable in the connection terminal chamber 46, it is possible to lead it out from the opening 50 and wire it outside the tank.

Further, the discharge side space 52 is provided in the pump casing 22.
An emergency shut-off valve 54 is provided therein and is configured to close the fluid passage in an emergency.

On the lower surface of the impeller 40 and the outer peripheral side surface of the inducer 38, partition walls 56 are provided at a distance from each other to form a double casing structure, and a liquid storage chamber 58 is provided between the two casings or between the two casings to suck the fluid. To perform.

Reference numeral 60 is an inlet, 62 is an outlet, 64 is a rotor of the motor unit 30, 66 is a bearing, 68 is a front bearing housing, and 69 is a rear bearing housing.

Next, in order to discharge the liquefied gas to the outside using the fluid discharge device configured as described above, first, in the discharge port 62 of the pump casing 22 which also serves as a manhole cover, an emergency shutoff having a built-in overcurrent detector is provided. The device 70 is replaced by the emergency shutoff device 70.
The emergency shutoff valve 54 is inserted into the discharge side space 52 in the pump casing 22, and is fixed liquid-tightly by the mounting bolt 55 via the gasket 26. Reference numeral 72 is an emergency shutoff valve release operation rod fitting projection.

Further, the inside of the canned motor pump used in the fluid discharge device of the present invention is always filled with the liquefied gas which is the liquid to be handled when the tank is loaded, so that it can be immediately driven. Connect the external power cable to the conductor 4 in the terminal chamber 46.
After connecting to No. 2 and switching off, the inside of the tank 18 and the inside of the piping system from the suction side tank are first made equal in pressure, and then the valve device is opened by the opening / closing handle. Then, by operating the drive switch of the canned motor pump, the liquefied gas is discharged and transferred into the suction side tank. After the transfer of the liquefied gas is completed, the valve device on the tank 18 side and the valve device at the end of the piping system from the suction side tank are closed to disconnect the piping.

As described above, since the fluid discharge device of the present embodiment is fixed to the manhole 20 provided at the bottom of the tank 18, the bottom of the pump casing 22 that also serves as the manhole cover can be set at a position lower than the tank bottom. This allows the pump suction port 60 to be installed at a position sufficiently lower than the bottom of the tank.

Further, when discharging the liquefied gas in the tank, the liquefied gas flowing from a fluid intake port (not shown) near the end surface of the inward protruding portion of the pump casing 22 passes through the liquid storage chamber 58 of the pump casing 22. Guided to the bottom. At this time, since the liquefied gas filling the liquid reservoir chamber 58 contacts the inducer 38 and the impeller 40, a vortex flow is generated in the liquid reservoir chamber 58 to hinder the smooth flow of the liquefied gas to the bottom. In the device of the present invention, the rotor 38 interferes with the fluid in the liquid storage chamber 58 by providing the partition wall 56 slightly apart from the surfaces of the inductor 38 and the impeller 40 in contact with the fluid in the liquid storage chamber 58. Is being prevented.

Further, the liquefied gas introduced into the inner bottom portion of the pump casing 22 is introduced from the suction port 60 opening at the end portion of the partition wall 56 to the tip end portion of the inducer 38 to the impeller 40 at the upper portion by the action of the inducer 38. After the pressure is introduced into the pump chamber, the discharge space 52 and the emergency shutoff valve 5 are passed through the discharge passage provided on the pump casing 22 side.
Then, it is discharged from the discharge port 62 into the piping system.

In this case, if the discharge flow rate increases for some reason and exceeds a preset limit value, the emergency shutoff valve 54 closes, and thus the discharge of the liquid from the tank 18 is stopped.
Even in this state, the operating state of the pump does not change at all, and the state is the same as that of the dead-end operation. Therefore, after the discharge side valve is closed once, the discharge is restarted while slowly opening again.

[Effects of the Invention] As is apparent from the above-described embodiments, according to the device of the present invention, the manhole cover is provided with a liquid reservoir communicating with the inside of the tank, and the pump of the immersion type canned motor pump is provided in the liquid reservoir. The casing is inserted and the pump inlet is exposed to the bottom of the liquid storage chamber, and the pump casing is integrally formed with the lid so as to be positioned sufficiently lower than the bottom of the tank. A discharge port that communicates with the discharge part of the pump casing is provided to discharge the fluid inside the tank through the liquid storage chamber, thereby firmly mounting the submersible canned motor pump on the lid. Moreover, a structure with excellent sealing performance is realized with a simple structure, and as a result, there is little need for pump maintenance, and there is little risk of leakage of liquefied gas from the discharge piping system. Moreover, even in the case of an unexpected situation such as a traffic accident, the damage and influence thereof can be suppressed to a minimum.

Particularly, in the device of the present invention, the terminal chamber is provided adjacent to the liquid reservoir of the pump casing, and the lead wire led out from the motor part is passed through the lid through the tea pipe and the guide pipe to reach the terminal chamber. By guiding and connecting the conductor wire and the external power cable in the terminal chamber, it is not necessary to separately provide a terminal box as in the conventional case, and this terminal chamber is integrated with the pump casing. This has the advantage that the structure and wiring of the conductors can be simplified, and the connection work and maintenance work with the external power supply cable can be simplified.

Further, in the device of the present invention, since the emergency shutoff valve can be simply installed in the discharge side space located downstream of the pump discharge part in the pump casing, the gas generation on the suction side due to the resistance of the emergency shutoff valve is facilitated. Can be prevented,
The liquid in the tank can be discharged more smoothly.

Further, with the above-described configuration of the device of the present invention, all of the piping connection, the valve device opening / closing operation, the wiring work from the external power supply, the motor driving / stopping operation, and the like accompanying the discharge work of the liquefied gas are performed on the ground and Since it can be carried out at a specific place, the work is safe and many practically excellent effects such as being able to cope with an emergency in a short time can be obtained.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and it is needless to say that various improvements and modifications can be made without departing from the spirit of the present invention.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a schematic structure of a tank truck tank adopting a conventional fluid discharge device, and FIG. 2 is a schematic explanatory view showing an embodiment of a tank truck tank adopting a fluid discharge device according to the present invention. FIG. 2 is a sectional view of the essential parts of the fluid discharge device according to the present invention shown in FIG. 18 ... Tank, 20 ... Manhole 22 ... Pump casing, 24 ... Flange part 26 ... Gasket, 28 ... Stud bolt 30 Motor part, 32 ... Flange part 34 ... Mounting bolt, 36 ... Motor shaft 38 ... Inducer, 40 ... Impeller 42 ... Conductor wire, 44 ... Wiring pipe 45 ... Tea pipe 46 ... Terminal chamber, 48 ... Stator 50 ... Opening part, 52 ... Discharge side space 54 ... Emergency shutoff valve, 55 ... Mounting bolt 56 ... Partition wall, 58 ... Liquid reservoir chamber 60 … Suction port, 62… Discharge port 64… Rotor, 66… Bearing 68… Front bearing housing 69… Rear bearing housing 70… Emergency shutoff device 72… Emergency shutoff valve release operation rod fitting projection

Claims (1)

[Scope of utility model registration request] 1. A manhole is provided at a tank bottom of a tank truck for storing and transporting a fluid such as liquefied gas, and a lid chamber of the manhole is provided with a liquid storage chamber communicating with the inside of the tank. An immersion type cand is provided in the liquid storage chamber. The pump casing of the motor pump is inserted and the pump inlet is exposed to the bottom of the liquid storage chamber, and the pump casing is formed integrally with the lid so as to be positioned sufficiently lower than the bottom of the tank. In a fluid discharge device configured to discharge a fluid inside a tank through the liquid storage chamber by providing a discharge port communicating with a discharge part of the pump casing in a part of the body, the fluid discharge device is provided in a part of the lid body. A fluid characterized in that an emergency shutoff device is provided at the discharge port of the pump casing with the emergency shutoff valve of this emergency shutoff device inserted in the discharge port side space in the pump casing. Ejection device.