JPH0618150Y2 - 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 procedure is restricted, and the length of the piping system increases the possibility of leakage of liquefied gas, In addition, there are many dangers of damage to the piping system and the 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 when the liquid level in the tank becomes low, the suction side As a result, gas is likely to be generated, and it is impossible to discharge all the liquid in the tank.

Further, as shown in FIG. 2, in the case of the type in which the immersion type canned motor pump is inserted and suspended in the tank tank tank, the manhole 2 provided above the tank 20 is used.
Inserting a submersible canned motor pump 24 into the tank from 2 and suspending it, extending a discharge pipe 26 upward from this pump 24, penetrating a manhole cover 27 and communicating with a discharge port 28 outside the tank. To do. The conductive cable of the canned motor is inserted into a protective tube provided in parallel with the pipe 26, penetrates the manhole cover 27, and is guided into a connection terminal box 29 provided outside the tank. In this case, by providing a manhole in the upper part of the tank, the center of gravity becomes high and the running stability of the tank lorry becomes a problem.Because the discharge port is located in the upper part of the tank, the pipe extends to the upper part of the tank. Increase the possibility of gas leaks,
In addition, there is a problem that the risk of damage to the piping system and pump due to a traffic accident increases. Further, according to such a model, since the bottom of the tank 20 is a curved surface, the suction port 25 of the submersible canned motor pump 24 cannot be brought into close contact with the bottom of the tank, so that all the liquefied gas in the tank is discharged. However, there was a problem that some of them remained.

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 plate that is detachably attached to the opening provided in the 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. Since the structure of the pump has been added, the structure becomes more complicated, and the smooth and efficient discharge of the liquid in the tank by the pump device is unsolved, and there are many practical problems.

Therefore, when the submersible canned motor pump is mounted on the lower part of the tank truck, the object of the present invention is to simplify the structure without restricting the tank capacity to improve the airtightness, and to require almost no maintenance of the pump. At the same time, there is little risk of leakage of liquefied gas from the discharge piping system, and even in the event of an accident such as a traffic accident, the damage and impact can be minimized, and the liquefied gas is discharged. In this case, the position of the pump suction side is lower than the bottom of the tank, so that the liquid remaining in the tank can be eliminated and efficient pump operation can be realized. To provide.

[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, the discharge port communicating with the discharge portion of the pump casing is provided in a part of the lid body. Inside the pump suction port facing the bottom, the impeller of the submersible canned motor pump and the inducer coaxially coupled to the impeller are separated from the surface in contact with the liquid in the flow path. A feature is that a partition is provided.

[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,
By providing a discharge port communicating with the discharge part of the pump casing in a part of the lid and discharging the fluid inside the tank through the liquid reservoir, the lid of the immersion type canned motor pump is formed. It can be firmly and easily mounted on the bottom of the tank, and the pump casing can be configured to be sufficiently lower than the bottom of the tank. By providing an inducer axially coupled with the impeller of the pump inside the facing pump suction port, it is possible to eliminate residual liquid in the tank and realize efficient pump operation.

〔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. 3 is a tank 3 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.
It shows 0. However, a manhole 32 is provided at the bottom of the tank 30, and a pump casing 34 of the immersion type canned motor pump is attached to the manhole 32. Therefore, a flange portion 35 is provided on the outer peripheral edge of the pump casing 34 to integrally form a manhole cover, and the manhole cover is liquid-tightly fixed to the manhole 32. Pump casing 3 that doubles as this lid
4 is provided with a concave portion for accommodating the impeller and the inducer of the canned motor pump, and the bottom portion of the concave portion is structured and arranged so as to be located at a position lower than the bottom portion of the tank 30. Further, the motor portion 36 fixed to the pump casing 34 is inserted and supported in the tank.

FIG. 4 shows details of the mounting structure of the immersion type canned motor pump in the manhole 32. That is, in FIG. 4, the pump casing 34 also serves as a cover plate for the manhole 32, and is made of a metal material suitable for the type of liquid to be loaded on the tank truck, and the flange portion 35 is provided on the outer edge of the pump casing 34. The flange portion 35 is circumferentially provided and is liquid-tightly fixed to the manhole 32 by a stud bolt 40 via a gasket 38.

On the end surface of the pump casing 34, the motor portion 36 of the submersible canned motor pump is mounted in a liquid-tight manner via a mounting bolt 44 by a flange portion 42 extending to the end portion.

The motor shaft 46 of the motor unit 36 is connected to the pump casing 34.
An inducer 48 and an impeller 50 are axially attached to the tip end of the extender 48.

The conductive cable 52 led out from the motor portion 36 passes through the inside of the wiring pipe 54 and is guided into the connection terminal chamber 56 provided in the hollow portion of the pump casing 34. The conductive cable 52 is connected from the stator 58 of the motor unit 36 to the wiring pipe 54.
Up to the middle, complete insulation is provided by resin filling etc. to prevent explosion. It is also possible to lead the terminal of the conductive cable 52 from the opening 60 of the connection terminal chamber 56 and wire it outside the tank.

Further, the discharge side space 62 in the pump casing 34
An emergency shutoff valve (not shown) may be provided therein.

On the lower surface of the impeller 50 and the outer peripheral side surface of the inducer 48, partition walls 64 are provided at a slight distance from each other to form a double casing structure, and a liquid storage chamber 66 is provided between the two casings or between the two casings to suck the fluid. To perform.

Reference numeral 68 is a suction port, 70 is a discharge port, 72 is a rotor of the motor unit 36, 74 is a bearing, 76 is a front bearing housing, and 78 is a rear bearing housing.

To discharge the liquefied gas to the outside by using the fluid discharge device configured as described above, for example, a valve device provided in the joint pipe connected to the discharge port of the pump casing 34 also serving as the manhole cover is used to discharge the liquefied gas. In a state where the outlet is closed, the pipe from the suction side tank to which the liquefied gas is transferred is connected to the joint pipe. Further, the inside of the submersible canned motor pump used in the fluid discharge device of the present invention is always filled with liquefied gas which is a liquid to be handled during loading in the tank, and can be immediately driven.
The external power cable is connected to the inside of the connection terminal chamber 56, and in the switch-off state, the tank 30 and the piping system from the suction side tank are first made to have an equal pressure, and then the valve device is opened by the opening / closing handle 37. . Next, by operating the drive switch of the immersion type 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 side of the tank 30 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 32 provided at the bottom of the tank 30, it is possible to set the bottom of the pump casing 34, which also functions as the manhole cover, at a position lower than the tank bottom. This allows the pump suction port 68 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 liquid intake (not shown) near the end face of the inward protruding portion of the pump casing 34 passes through the liquid reservoir chamber 66 of the pump casing 34. Guided to the bottom. At this time, since the liquefied gas filling the liquid reservoir chamber 66 contacts the inducer 48 and the impeller 50, a vortex flow is generated in the liquid reservoir chamber 66 to hinder the smooth flow of the liquefied gas to the bottom. In the device of the present invention, the rotor 48 interferes with the fluid in the liquid storage chamber 66 by providing the partition wall 64 slightly apart from the surfaces of the inductor 48 and the impeller 50 in contact with the fluid in the liquid storage chamber 66. Is being prevented.

Further, the liquefied gas introduced into the inner bottom portion of the pump casing 34 is sucked from the suction port 68 opened at the end portion of the partition wall 64 to the tip end portion of the inducer 48, and then the liquefied gas of the impeller 50 located at the upper portion by the action of the inductor 48. After being pressurized in the pump chamber, it passes through the discharge passage provided on the pump casing 34 side, passes through the discharge side space 62, and the discharge port 70.
Is discharged into the piping system.

[Effect of device]

As is apparent from the above-described embodiment, according to the 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. Along with the pump suction port facing the bottom of the liquid storage chamber, the pump casing is integrally formed with the lid so as to be at a position sufficiently lower than the bottom of the tank, and a part of the lid has the pump casing By providing a discharge port that communicates with the discharge unit and discharging the fluid inside the tank through the liquid reservoir, the immersion type canned motor pump can be firmly and easily attached to the lid. Achieves a structure with excellent airtightness, resulting in a structure requiring almost no maintenance of the pump, and there is little risk of leakage of liquefied gas from the discharge piping system, and traffic Also in eventuality etc. can suppress the damage and impact to a minimum.

Further, the pump casing is configured to be positioned sufficiently lower than the bottom of the tank, and the impeller of the pump and an inductor coaxially connected to the impeller flow inside the pump suction port facing the bottom of the liquid reservoir. By providing the partition wall apart from the surface in contact with the liquid in the passage, the liquefied gas in the tank can be completely discharged without inhaling the vaporized gas from the pump suction port.

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 and FIG. 2 are explanatory views each showing a schematic configuration of a tank truck which adopts a conventional fluid discharging device, and FIG. 3 is a schematic showing an embodiment of a tank truck which adopts a fluid discharging device according to the present invention. Explanatory drawing and FIG. 4 are cross-sectional views of essential parts of the fluid discharge device according to the present invention shown in FIG. 30 ... Tank, 32 ... Manhole 34 ... Pump casing, 35 ... Flange part 36 ... Motor part, 38 ... Gasket 40 ... Stud bolt, 42 ... Flange part 44 ... Mounting bolt, 46 ... Motor shaft 48 ... Inducer, 50 ... Impeller 52 ... Conductive cable, 54 ... Wiring pipe 56 ... Wiring terminal chamber, 58 ... Stator 60 ... Opening part, 62 ... Discharge side space 64 ... Partition, 66 ... Liquid reservoir chamber 68 ... Suction port, 70 ... Discharge port 72 ... Rotor, 74… Bearing 76… Front bearing housing 78… Rear bearing housing

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. 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 portion of the pump casing in a part of the body, wherein the pump faces the bottom of the liquid storage chamber. A partition wall should be provided inside the suction port, away from the surface of the impeller of the submersible canned motor pump and the inducer that is coaxially coupled to the impeller and that contacts the liquid in the flow path. A fluid discharge device.