JP2018112070A - Fluid delivery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid delivery device which enables gas drainage from a motor pump to be securely performed even if a non-return valve is provided at a discharge pipeline.SOLUTION: A canned motor pump 12 has: a suction port 22 provided at a lower part; a discharge port 23 provided at an upper part; and a motor pump body 21 which suctions a fluid from the suction port 22 and discharges the fluid from the discharge port 23. A discharge pipeline 13 is connected to the discharge port 23, and a non-return valve 50 is provided at a middle position of the discharge pipeline 13. A lower part of a gas drainage pipeline 51 is connected to the side below the non-return valve 50 of the discharge pipeline 13, and an upper part of the gas drainage pipeline 51 is connected to the side above the non-return valve 50 of the discharge pipeline 13. A gas drainage valve 52 which opens or closes the gas drainage pipeline 51 is provided in a liquid delivery device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fluid delivery device that delivers fluid.

  2. Description of the Related Art Conventionally, for example, a canned motor pump or the like is used to send a liquid that is easily vaporized, such as a liquefied gas, as a fluid stored in a storage unit from a storage unit to a predetermined delivery location. In the canned motor pump, pump handling liquid is circulated in the canned motor pump for cooling and lubrication of the canned motor pump. The gas which a part of pump handling liquid vaporized in the canned motor pump is returned to a storage part through a reverse line (for example, refer patent document 1).

  In this case, it is necessary to install a reverse line for venting the gas from the canned motor pump, and there is a problem that the equipment becomes complicated.

  Further, by using a canned motor pump having a suction port in the lower portion and a discharge port in the upper portion, it becomes possible to easily escape the gas from the canned motor pump (see, for example, Patent Document 2).

  However, when a check valve is provided in the discharge pipe connected to the discharge port, the gas that has been vaporized in the pump handling liquid due to the heat immediately after the operation of the canned motor pump is stopped, from the canned motor pump to the check valve. There is a possibility that it may remain, and there is a problem that the canned motor pump is troubled by gas biting and that it cannot be restarted for, for example, 1 to 2 hours after the canned motor pump stops.

Japanese Patent Laid-Open No. 8-200294 JP 2005-344696 A

  As described above, when a check valve is provided in the discharge pipe, degassing from the motor pump becomes a problem.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a fluid delivery device capable of reliably venting gas from a motor pump even when a check valve is provided in a discharge pipe.

  A fluid delivery device according to claim 1, wherein a motor pump having a suction port provided in a lower portion, a discharge port provided in an upper portion, and a motor pump body that sucks fluid from the suction port and discharges the fluid from the discharge port; A discharge pipe connected to the discharge port, a check valve provided in the middle of the discharge pipe, a lower part connected to the lower side of the check valve of the discharge pipe, and an upper part of the discharge pipe A degassing pipe connected above the check valve and a degassing valve for opening and closing the degassing pipe.

  The fluid delivery device according to claim 2, wherein the fluid delivery device according to claim 1 is provided in the discharge pipe above the connection portion to which the upper part of the gas vent pipe is connected, and opens and closes the discharge pipe. It comprises.

  According to the fluid delivery device of the first aspect, even if a check valve is provided in the discharge pipe, the gas can be reliably vented from the motor pump.

  According to the fluid delivery device of the second aspect, in addition to the effect of the fluid delivery device of the first aspect, by closing the discharge pipe when the gas vent valve is opened, the back flow of the fluid from the gas vent pipe to the motor pump Can be prevented.

It is a front view of the fluid delivery apparatus which shows one embodiment. It is sectional drawing of the canned motor pump of a fluid delivery apparatus same as the above.

  Hereinafter, an embodiment will be described with reference to the drawings.

  In FIG. 1, the fluid delivery device 10 delivers, for example, a liquid that is easily vaporized such as a liquefied gas as a fluid stored in the storage unit from the storage unit to a predetermined delivery location.

  The fluid delivery device 10 includes a suction pipe 11 connected to the reservoir, a canned motor pump 12 as a motor pump having the suction pipe 11 connected to the lower suction side, and an upper discharge side of the canned motor pump 12. A discharge pipe 13 is provided which is connected and extends toward a predetermined delivery place.

  In the fluid delivery device 10 of the present embodiment, two canned motor pumps 12 are used, and a branch pipe portion 11a of the suction pipe 11 and a branch pipe portion 13a of the discharge pipe 13 are parallel to the two canned motor pumps 12, respectively. It is connected.

  As shown in FIG. 2, the canned motor pump 12 is a vertical type, and includes a casing 20 and a motor pump main body 21 disposed in the casing 20.

  The casing 20 has a cylindrical shape that is long in the vertical direction. A suction port 22 to which the suction pipe 11 is connected is formed in the lower part, and a discharge port 23 to which the discharge pipe 13 is connected is formed in the upper part.

  The motor pump main body 21 includes a motor unit 24 and a pump unit 25 driven by the motor unit 24.

  In the motor unit 24, a stator 28 formed by winding a stator winding 27 around a stator core 26 is inserted inside the casing 20, and a thin cylindrical stator can 29 is formed on the inner peripheral surface of the stator 28. The both ends of the stator can 29 are tightly inserted and are liquid-tightly welded to the casing 20. A rotating shaft 33 is inserted into a rotor 32 formed by mounting a rotor conductor 31 on the rotor core 30, and a thin cylindrical rotor can 34 is attached to the outer peripheral surface of the rotor 32. Then, the stator 28 and the rotor 32 are opposed to each other through a can gap 35 between the stator can 29 and the rotor can 34, and the rotary shaft 33 has a bearing 36 in each of the lower, middle and upper stages with respect to the casing 20. It is pivotally supported by 37 and 38.

  The pump unit 25 includes a plurality of impellers 39, 40, and 41 attached to the lower, middle, and upper stages of the rotary shaft 33, and pump casings 42, 43, and 44 in which the impellers 39, 40, and 41 are disposed. I have.

  Then, in the casing 20, from the suction port 22 to the discharge port 23 through the lower impeller 39, the lower bearing 36, the middle impeller 40, the middle bearing 37, the can gap 35, the upper bearing 38, and the upper impeller 41. A leading flow path 45 is formed. Accordingly, the plurality of impellers 39, 40, 41 rotate together with the rotating shaft 33 by driving the motor unit 24, whereby liquid is sucked into the discharge port 22 from the suction pipe 11, and the discharge port 23 passes through the inside of the canned motor pump 12. To the discharge pipe 13.

  The discharge pipe 13 is connected to the discharge port 23 of the canned motor pump 12 and extends upward. A check valve (check valve) 50 is provided in the middle of the discharge pipe 13 in the vertical direction. The check valve 50 allows the liquid discharged from the discharge port 23 toward the discharge pipe 13 to flow, and blocks the flow of the liquid that attempts to flow backward from the discharge pipe 13 toward the discharge port 23.

  A gas vent pipe 51 is provided in parallel with a part of the discharge pipe 13. The lower part of the gas vent pipe 51 is connected to a position below the check valve 50 of the discharge pipe 13, and the upper part of the gas vent pipe 51 is connected to an upper position than the check valve 50 of the discharge pipe 13. That is, the gas vent pipe 51 is configured as a bypass pipe that bypasses the check valve 50 of the discharge pipe 13. Note that the lower part of the gas vent pipe 51 is preferably connected to a position as close as possible to the check valve 50 of the discharge pipe 13.

  The gas vent pipe 51 is provided with a gas vent valve 52 that opens and closes the gas vent pipe 51.

  The discharge pipe 13 is provided with a discharge valve 53 that opens and closes the discharge pipe 13 at a position above the connection portion to which the upper part of the gas vent pipe 51 is connected. A branch pipe portion 13 a of the discharge pipe 13 connected to the discharge port 23 of each canned motor pump 12 is joined on the downstream side of the discharge valve 53.

  Next, the operation of the fluid delivery device 10 will be described.

  When delivering the liquid in the reservoir, the motor unit 24 of the canned motor pump 12 is driven and the discharge valve 53 is opened. At this time, the gas vent valve 52 is closed.

  By driving the motor unit 24 of the canned motor pump 12, the plurality of impellers 39, 40, 41 rotate together with the rotating shaft 33, and the liquid in the reservoir is sucked into the discharge port 22 from the suction pipe 11 to Then, the gas is discharged from the discharge port 23 to the discharge pipe 13 through the flow passage 45. As the liquid flows through the flow passage 45 inside the canned motor pump 12, the motor unit 24 is cooled and the bearings 36 to 38 are lubricated.

  At this time, the lower impeller 39 is positioned below the lower bearing 36 serving as a suction resistance and plays a role of improving the suction efficiency. The middle multi-stage impeller 40 plays a role of obtaining a predetermined discharge pressure according to the specification. The upper impeller 41 plays a role of compensating for the pressure loss lost when passing through the motor unit 24.

  Then, the liquid discharged from the discharge port 23 of the canned motor pump 12 to the discharge pipe 13 passes through the check valve 50 and the discharge valve 53 and is sent to a predetermined delivery place by the discharge pipe 13.

  When the liquid delivery is stopped, the drive of the motor unit 24 of the canned motor pump 12 is stopped and the discharge valve 53 is closed.

  When a part of the liquid is vaporized due to the residual heat of the motor unit 24 after the motor unit 24 is stopped, the vaporized gas flows so as to float upward in the flow path 45 and escapes from the discharge port 23 to the discharge pipe 13. For this reason, gas can easily escape from the canned motor pump 12.

  The gas that has escaped into the discharge pipe 13 is blocked by the check valve 50 and easily accumulates in the discharge pipe 13. When the amount of vaporized gas is large, the gas may remain from the check valve 50 to the inside of the canned motor pump 12.

  Therefore, the gas vent valve 52 is opened. By opening the gas vent valve 52, the gas blocked by the check valve 50 flows to the discharge valve 53 through the gas vent pipe 51, and conversely, the liquid between the discharge valve 53 and the gas vent valve 52 flows. The gas flows down to the lower side of the check valve 50 through the gas vent pipe 52 and fills the inside of the canned motor pump 12 with liquid.

  The gas vent valve 52 may be opened when the motor unit 24 is stopped, or may be opened after a predetermined time from when the motor unit 24 is stopped.

  When the liquid delivery is resumed, the motor unit 24 of the canned motor pump 12 is driven to close the gas vent valve 52 and open the discharge valve 53. Thereby, the delivery of the liquid is resumed.

  In the fluid delivery device 10 configured in this way, the gas inside the canned motor pump 12 is discharged from the discharge port 23 by using the suction port 22 on the lower side and the discharge port 23 on the upper side and the canned motor pump 12 in a vertical type. It can be easily removed.

  Furthermore, even if the check valve 50 is provided in the discharge pipe 13, the gas below the check valve 50 of the discharge pipe 13 can be sent to the upper side of the check valve 50 through the gas vent pipe 51. The degassing from the canned motor pump 12 can be ensured.

  In this case, as in the case of returning from the canned motor pump 12 to the storage section through the reverse line, the equipment can be handled with a simple configuration without being complicated.

  Moreover, even after the canned motor pump 12 is stopped, the canned motor pump 12 can be restarted immediately by degassing.

  Further, when the gas vent valve 52 is opened, the discharge pipe 13 is closed by the discharge valve 53, whereby the backflow of liquid from the gas vent pipe 51 to the canned motor pump 12 can be prevented.

  Note that the fluid delivery device 10 is not limited to the case where two canned motor pumps 12 are used, but only one may be used, or three or more may be used.

  Further, by using a ball bearing for at least a part of the bearings 36 to 38 of the canned motor pump 12, it is possible to easily vent the gas from the inside of the canned motor pump 12.

10 Fluid delivery device
12 Canned motor pump as motor pump
13 Discharge piping
21 Motor pump body
22 Suction port
23 Discharge port
50 Check valve
51 Gas vent piping
52 Gas vent valve
53 Discharge valve

Claims (2)

A motor pump having a suction port provided in the lower portion, a discharge port provided in the upper portion, and a motor pump body that sucks fluid from the suction port and discharges it from the discharge port;
A discharge pipe connected to the discharge port;
A check valve provided in the middle of the discharge pipe;
A gas vent pipe whose lower part is connected to the lower side of the check valve of the discharge pipe and whose upper part is connected to the upper side of the check valve of the discharge pipe;
A fluid delivery device comprising: a gas vent valve that opens and closes the gas vent pipe. The fluid delivery device according to claim 1, further comprising a discharge valve provided in the discharge pipe above a connection portion to which an upper portion of the gas vent pipe is connected, and opening and closing the discharge pipe.

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