JPS58183891A - Glandless pump - Google Patents

Abstract

PURPOSE:To prevent generation of cavitation in a motor by a method wherein a part of handling liquid, pressurized by an impeller, is pressurized by a rear vane to a pressure higher than the discharging pressure of the pump and is introduced into a canned motor from the scroll chamber of the pump through a path therefor. CONSTITUTION:A part of the handling liquid 48, pressurized by the impeller 35, is pressurized by the rear vane 42 to a pressure higher than the discharging pressure of the pump and is introduced into the canned motor 21 from the scroll chamber 43a of the pump through the paths 44, 45 as shown by arrow signs in the diagram. Thus, the handling liquid 48 in the canned motor 21 is being pressurized, however, the pressure thereof is showing a pressure between the discharging pressure of the rear vane 42 and the same of the pump and, therefore, it becomes higher than the discharging pressure of the pump. Accordingly, there is no fear to generate the cavitation in the canned motor 21 and, therefore, lubrication of the bearings 32, 33 as well as the cooling of the canned motor 21 may be effected surely.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a Guérande dress pump, and relates to a circulation system of a Guérande dress pump that handles liquids with high vapor pressure such as liquefied gas and liquids operated at temperatures close to the boiling point. Regarding improvements.

[Technical background of the invention and its problems]

The Guérandeless pump has a completely leak-free structure with no shaft seals by integrating the pump and motor into one unit.The motor is cooled by a stator can made of non-magnetic thin metal for the bearing lubricating fluid that also serves as motor cooling. There are canned motor pumps, which have a structure in which the stator of the motor is isolated, and wet motor pumps, which have a structure in which the stator of the motor is also immersed.In both cases, the bearings are generally cleaned by circulating a portion of the pump fluid. and motor cooling.

For example, in a "canned motor pump KN" having a camphor structure, as shown in Figure 1, the pump discharge side 111 and the pump (3) side of the canned motor (2) are opposite to each other. A part of the pump handling liquid (51) on the pump discharge side (1) is communicated with the pump discharge side (1) through the circulation vibrator (4) due to the pressure difference between the pump discharge pressure P and the pump suction pressure P. The force is introduced into the rear end of the canned motor (2) through the rear end of the canned motor (2), lubricates the rear bearing (6), and the stator (1G and A structure is adopted in which the rotor 0υ is cooled, the front bearing α2 is lubricated, and the pump impeller 0 is circulated back from the balance hole 04 to the pump suction side o9. 5) approaches the pump (3) side from the end of the canned motor (2) (as the pressure approaches the pump suction pressure P.K, R and its temperature increase as the canned motor (2)
), it rises by taking away the heat, that is, it becomes high temperature and low pressure.
Cavitation is likely to occur when handling liquids with high vapor pressure such as liquefied gas or liquids that are operated at temperatures close to the boiling point, resulting in poor cleaning of the front bearing and abnormal wear or seizure, which can lead to pump failure. It generates noise and vibration, resulting in performance deterioration.
There is a possibility that it will eventually become impossible to pump the liquid.

On the other hand, a part of the pump handling liquid on the pump discharge side is introduced into the front bearing side of the canned motor, and flows inside the canned motor from the target bearing through the gap between the stator can and the rotary calf can to the rear bearing. There is a reverse circulation method in which the vapor is passed through and returned to the vapor zone of the suction tank using reverse piping for circulation.However, since the flow path resistance of the reverse piping system differs depending on the device, the circulation flow rate must be adjusted in advance using the canned motor pump alone. The problem is that the piping equipment is complicated, such as the need to adjust the circulation flow rate using a valve or the like installed in the middle of the reverse piping after it is installed in the device, and the operation is troublesome.

In addition, an auxiliary pump is installed inside the canned motor, and the action of this auxiliary pump allows circulating fluid independent of the pump handling fluid to flow from the rear bearing through the gap between the stator can and rotor can to the front bearing inside the canned motor. There is also an independent circulation method in which the heat is passed through the front bearing and then circulated back to the rear bearing via the heat exchanger, but this requires the auxiliary pump, heat exchanger, and cooling water equipment for this heat exchanger. Due to the high price,
Furthermore, since the circulating fluid is basically the same as the pump handling fluid, if these fluids are chemically unstable, they may deteriorate over a long period of time, and maintenance management is extremely troublesome.

[Object of the invention]

As a result of the above-mentioned Km-inspection test, the present inventor has determined that a part of the pump handling liquid (5) on the pump discharge side (1) is passed through the circulation vibrator (4) to the canned motor (2) as shown in Figure 2. ) and pass through the canned motor (2) from the rear bearing (6) through the gap (9) between the force and the rotor can (8) to the front bearing α2, and then pass through the canned motor (2) to the final stage. According to the multiple canned motor pump, which circulates from the balance hole (14, I) of the pump impeller (13,) back to the final stage pump suction side (15,), the air passing through the canned motor (2) The pump handling liquid (5) is returned to a relatively high pressure side, which is closer to the pump discharge pressure P, k than the pump suction pressure P0, so the pressure of the circulation flow is also high and cavitation is extremely unlikely to occur. Focusing on the single-stage Guerandless pump, we installed a back blade on the pump impeller that cooperates with the final stage pump impeller in the multi-stage canned motor pump, and the pump 1 root wheel pressure was increased before the st stage. A part of the pump salt IQ is guided to the back blade and further pressurized to lubricate the front bearing, cool the stator and rotor of the motor, lubricate the rear bearing, and pass through the inside of the motor.
The circulation pipe is returned to the pump discharge side corresponding to the suction side of the final stage of the multi-stage canned motor pump to form a two-stage pump for circulating flow, and a single-stage pump for the main flow of the pump. By configuring the pump,
There is no risk of cavitation in the liquid handled by the pump, such as liquids with high vapor pressure such as liquefied gas or liquids operated at mi close to the boiling point due to high pressure in the circulating RR, and cans with a standard structure as shown in the above IM. By simply converting some parts of the motor pump or Watt-type motor pump, there is no need for reverse piping or valves in the reverse circulation method, or auxiliary pumps, heat exchangers, and cooling water equipment in the independent circulation method, making it extremely inexpensive. , which offers a single-stage Guérandeless pump that is easy to operate and maintain.

[Summary of the invention]

The structure of the Guérande-less pump of the present invention is such that a fixed orifice on the outer diameter part and a fixed orifice on the inner diameter part are formed from the rear wall body of the pump casing of the Guérande-less pump, the pump impeller, and K, respectively. A back blade is provided between the fixed orifices, one end communicates with the pop discharge side and the other end communicates between the inner diameter fixed orifice and the back blade, and one end connects to the outer diameter fixed orifice.
A passageway is provided in the rear wall body of the pump casing, the other end of which communicates with the J vane and the other end communicates with the motor side from the inner diameter part rMI leg orifice, and the end opposite to the pump side of the take motor. The part and the nNf4e pump discharge are connected through a circulation vibrator.

[Embodiments of the invention]

Next, an embodiment in which the present invention is applied to a canned motor pump will be described based on Figure 3.

... is a canned motor pump that liquid-tightly combines a canned motor Ql) and a centrifugal pump. A stator &41 is inserted and fixed into the stator frame C23 of the Ai]8d canned motor Qυ, and this stator (2 A stator calf can 6 is tightly inserted into the inner periphery of the stator can 6, and both edges of the stator can 6 are connected to the front flange (23) formed at both ends of the stator frame.
, ) and the inner periphery of the rear 7 flange (23A) to seal the stator (2) in a liquid-tight manner.

Also, inside the identifier can QS+, there is a rotating shaft □□□
A rotating pre-soak fixed to and sealed by a rotor can α is disposed opposite to the stator (2) with a gap between the stator can (c) and the rotor can. An end 11G3G that also serves as a bearing box is fluid-tightly attached to the rear flange (234) of the stator frame, and a bearing box is attached to the front flange (23,) of the stator frame. A pump casing rear wall body 6υ that also serves as a
K rear bearings [with] are installed respectively, and both of the above-mentioned shafts *@(
The rotating shaft (e) is rotatably supported on the rotary shaft (e).

Also, the outside J of the pump casing rear wall body Gυ! dK is fitted with the pump casing (to), and this pump casing (b) is attached to the front flange (23,) of the stator frame @.
The pump casing (2) is fluid-tightly attached to the pump casing (2).
A pump blade 4 disposed inside the pump casing (b) is fixed to a rotating shaft (c) protruding inside the pump casing (b).

[Then, an annular ridge (36,) provided on the outer diameter of the rear plate (3) of the pump impeller G and an annular ridge (31,) provided on the outer diameter of the pump casing rear wall 6υ. An outer diameter fixed orifice □□□ is formed between W1 (9) which is narrower in the radial direction than K and the outer periphery of the boss (to) of the @I pipon impeller (c) and the rear wall of the pump casing. body C
A fixed orifice υ is formed on the inner diameter through a narrow radial gap (a) between the inner periphery of υ and the threshold.

A back printing *i43 is provided between the fixed orifices (to) μυ on the rear side of the west side of the pump impeller.

and a passageway (2) whose one end communicates with the pump vortex chamber (43,) on the pump discharge side (43) and whose other end communicates with the inner diameter fixed orifice (43);
- m is the spinning outer diameter fixed orifice (to) and the back blade -
A passageway (C) whose other end communicates between the inner diameter fixed orifice -D and the aforementioned bearing structure, that is, from the inner diameter fixed orifice to the canned motor Q1) is connected to the pump casing. It is provided on the rear wall body Qυ, and one end of the circulation vibe μs is the pump discharge port (43h).
The other end of the canned motor Qυ is connected to the end cover, so that the rear end of the canned motor Qυ and the pump discharge 11LI are in liquid-tight communication.

(4η is the pump suction side of pump (2).

According to the embodiment configured in this way, the pump suction side I
The pump handling liquid (c) of D is the pump suction pressure P. is energized by the pump impeller &''QK, and the pump discharge pressure is increased to P on the pump discharge side Q3, and a part of the liquid handled by the pump (c) on this pump discharge side (c) is energized by the pump impeller &''QK, as shown by the arrow. It is introduced between the long blade I4 and the inner fixed orifice -υ from the pump vortex chamber (43a) through the passage G44), is urged by the back blade (43), and is further boosted to the back blade discharge pressure P2. It is introduced into the canned motor Qυ through the passage (c),
Clean the front shaft, cool the stator (2) and rotor (c) through the gap between the stator can 6 and the rotor can, and lubricate the rear bearing (to). It flows into the circulation vibrator (c), and while passing through the canned motor cylinder, it absorbs the heat of the canned motor 0V and is heated up.Then, the pressure is lowered to pump discharge pressure P1, and the pump is discharged from the circulation vibrator (c). It is returned to the discharge port (43k) and circulated.

Although the temperature of the liquid handled by the pump in the canned motor Qυ is raised in this way, its pressure is between the long blade discharge pressure P2 and the pump discharge pressure P, that is, the pressure is higher than the pump discharge pressure P. Therefore, there is no fear of cavitation occurring within the canned motor Qυ, and the bearing port is reliably lubricated and the canned motor CI'll is reliably cooled.

In addition, the pump handling liquid that has passed through the canned motor Qυ is at a sufficiently high pressure and is also returned to the pump discharge side, so there is no risk of cavities or cheesions occurring at the pump suction (1mk7), which reduces the performance of the pump. , it will not lead to inability to pump liquid.

According to the above embodiment, the canned motor pump having a standard structure as shown in Fig. 1 can be improved by simply replacing the rear wall of the pump casing and the pump impeller. A canned motor pump suitable for handling liquids and liquids operated at temperatures close to the boiling point can be obtained.

Note that the fixed orifice in the inner diameter section is 1. As shown in Figure t-4, 5 shows the annular ridge (36b) provided on the inner diameter of the rear plate ω of the pump impeller G and the rear wall Gυ of the pump casing.
The annular ridge (31b) provided on the inner diameter of the l! 1 (may be formed via 49,
In addition, the flow 6υ on the rear wall of the pump casing is adjusted between the front part 7 of the pump casing (to) and the stator frame (c) as shown in Figure 4.
Adapter liquid-tightly connected to the threshold with the lunge (23,) ■
, one end is the inner diameter identification orifice G4.
11 and the back blade (42) may also be fluid-tightly communicated with the pump discharge port (43A) via the circulation vibro υ.

Further, the present invention is not limited to the canned motor pump head, but also includes a wet type structure in which the stator can (c) of the canned motor pump head is removed and the stator (c) is also immersed in the pump handling liquid (c). It can also be adopted as a motor pump and can provide similar effects.

〔Effect of the invention〕

According to the Guérandeless pump of the present invention, an outer diameter fixed orifice and an inner diameter fixed orifice are formed by the rear wall of the pump casing of the Guérande pump and the pump impeller, respectively, and both of the fixed orifices of the pump impeller are fixed. A back blade is provided in the orifice section, one end of which communicates with the pump discharge side and the other end of which communicates between the inner diameter fixed orifice and the back blade, and one end of which communicates with the outer diameter fixed orifice and AfJ.
A passage is provided in the rear wall body of the pump casing, the other end of which communicates with the surface blade and which communicates with the motor 1 side from the inner diameter identification orifice, and an end opposite to the pump side of the fA Qif motor. The Guerlain pump, which has a standard structure, is suitable for handling liquids with high vapor pressure such as liquefied gas, liquids operated at temperatures close to the boiling point, etc., by connecting the pump outlet and the pump outlet with a circulation vibrator. It can be easily obtained by simply replacing some parts of the dress pump, and does not require reverse piping or valves in the reverse circulation system, or auxiliary pumps, heat exchangers, or cooling water equipment in the independent circulation system. It is inexpensive, easy to operate and maintain, and has extremely high practical value.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional Guérande dress pump, Figure 2 is a sectional view of a Guérande dress pump that is the premise of the present invention, and Figure 8
The figure is a sectional view of a Guérande dress pump showing one embodiment of the present invention, and Figure 4 is a sectional view of a part of a Guérande dress pump showing another embodiment of the invention.翰... Canned motor pump as Guerandless pump, Qυ... Canned motor, 6υ fighting pump casing rear wall, (2)... Pump casing, (To)... Pump impeller, Trowel... Outer diameter Part fixed orifice, Sir... Inner diameter fixed orifice, (6)... Back blade, @4-/0 passage, --Φ circulation vibe.

Claims (1)

[Claims] (1) A fixed orifice in the outer diameter part and a fixed orifice in the inner diameter part are respectively formed by the rear wall of the pump casing of the Guerandless pump and the pump impeller, and a back blade is provided between the two fixed orifices of the pump impeller. , a passage having one end communicating with the pump discharge side and the other end communicating between the inner diameter fixed orifice and the back blade, and a passage having one end communicating from the outer diameter fixed orifice to the motor side. A Guerand dress pump characterized in that the pump is provided on each rear wall body, and the end of the motor opposite to the pump side and the pump discharge side are communicated by a circulation pipe.