JPH0736149Y2 - Gas seal type motor pump - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial field of application) The present invention relates to a gas-sealed motor pump, in which the liquid handled by the pump in the gas-sealing chamber is polymerized or solidified to impair the gas-sealing function. It relates to a structure that prevents being exposed.

(Prior Art) Generally, a canned motor pump cools a stator and a rotor of the canned motor and lubricates a bearing by circulating a part of a pump handling liquid to the canned motor. When handling liquids such as contained liquids, high-viscosity liquids, liquids that tend to polymerize or solidify, or liquids that are highly corrosive to bearings that cause failure when circulated to the canned motor section, a gas-sealed canned motor A pump is used.

In this gas seal type canned motor pump, as shown in FIGS. 6 and 7, a canned motor unit 3 is airtightly integrated with an upper side of a pump unit 1 via a gas seal chamber 2. By mechanically sealing the rotor chamber 4 of 3 and the gas seal chamber 2 with a mechanical seal 5,
The pump handling liquid 7 that has flowed into the gas seal chamber 2 from the pump chamber 6 is blocked by the gas body 8 enclosed in the gas seal chamber 2 and does not reach the mechanical seal 5, that is, the canned motor unit 3 is removed from the pump handling liquid 7 It is configured to seal.

Further, as the rotating shaft 9 rotates, the pump handling liquid 7 in the gas seal chamber 2 is disturbed, so that the gas body 8 in the gas seal chamber 2 is caught in the pump handling liquid 7 and leaks into the pump chamber 6. By this amount, the pump handling liquid 7 flows from the pump chamber 6 into the gas seal chamber 2 and the liquid level of the gas seal chamber 2 rises, and finally reaches the mechanical seal 5 and the mechanical seal 5 is damaged. Since the gas seal action is impaired, a means for preventing the disturbance of the pump handling liquid 7 in the gas seal chamber 2 is necessary, and therefore the applicant of the present invention, as shown in FIG.
A structure was proposed in which a plurality of baffles 10a, 10b, 10c, 10d are radially arranged in the gas seal chamber 2 (Japanese Utility Model Publication No. 45-8285).

(Problems to be solved by the invention) However, due to the baffles 10a, 10b, 10c, and 10d provided to prevent the disturbance of the gas seal chamber 2, the pump handling liquid 7 in the gas seal chamber 2 naturally stagnates and is almost lost. When the pump handling liquid 7 is a liquid that easily causes polymerization or solidification, polymerization or solidification in the gas seal chamber 2 cannot be avoided because the liquid does not flow.

And as this polymerization or coagulation progresses,
Since the volume of the pump handling liquid 7 in the gas seal chamber 2 decreases and the actual volume of the gas seal chamber 2 decreases, when the canned motor pump is repeatedly operated and stopped, the pump handled liquid due to the pressure difference between the time of operation and the time of stop. The liquid level in the gas seal chamber 2 gradually rises with the inflow and outflow of the gas seal chamber 2 into the gas seal chamber 2,
That is, when the pump handling liquid 7 flows out from the gas seal chamber 2 into the pump chamber 6 due to the pressure difference between the time of operation and the time of stop, the amount of the pump handling liquid 7 in the gas seal chamber 2 is small, so that even the gas body 8 is present. The liquid level of the gas seal chamber 2 when it flows out into the pump chamber 6 and the pump handling liquid 7 flows into the gas seal chamber 2 from the pump chamber 6 due to the pressure difference, rises more than before and finally. When reaching the mechanical seal 5, the mechanical seal 5 is damaged and the gas sealing action is impaired.

Further, when the product resulting from the polymerization or solidification of the pump handling liquid 7 from the gas seal chamber 2 falls into the pump chamber 6 and is mixed into the pump discharge liquid, the quality of the product produced from the pump handling liquid 7 is deteriorated. There is also a risk of being invited.

Therefore, as shown in FIGS. 8 and 9, the pump discharge port 11 and the gas seal chamber 2 are connected and communicated with each other by the circulation pipe 12, and a part of the pump handling liquid 7 at the pump discharge port 11 is circulated. Through the gap 13 between the partition body 13 and the rotary shaft 9 that partition the gas seal chamber 2 and the pump chamber 6 from the gas seal chamber 2, and the balance hole 16 of the impeller 15 through the impeller. By guiding it to the suction side 17 of 15 and returning it to the pump discharge port 11 for circulation,
A part of the means for flowing the pump handling liquid 7 in the gas seal chamber 2 to prevent polymerization or coagulation is implemented, but the pump handling liquid 7 polymerizes or coagulates in the gas seal chamber 2 to impair the gas sealing action. Although I was able to extend the period until
Pump handling liquid 7 to the extent that the gas sealing action is not impaired
It has never been possible to prevent the polymerization or coagulation of.

Further, in the gas seal type canned motor pump of this configuration, since the pump discharge port 11 and the gas seal chamber 2 are connected and communicated with each other by the circulation pipe 12, an unexpected external force is applied during transportation, installation or inspection. If added, there is a drawback that the number of sealing points that may cause liquid leakage increases.

In addition to the gas-sealed motor pump driven by the canned motor as described above, the gas-sealed motor pump driven by a general-purpose motor has the same problem.

The present invention has been made in view of the above, and provides a gas-sealed motor pump which prevents polymerization or coagulation of a pump handling liquid in a gas-sealing chamber and does not impair the gas-sealing action.

[Constitution of device]

(Means for Solving the Problem) The present applicant has examined the cause that the polymerization or coagulation of the pump handling liquid 7 in the gas seal chamber 2 could not be prevented so much even by the configurations shown in FIGS. 8 and 9. As a result, a part of the pump handling liquid 7 in the gas discharge chamber 11 flows through the circulation pipe 12 into the gas seal chamber 2 so that a part of the pump handling liquid 7 in the gas seal chamber 2 flows. It was found that the pump handling liquid 7 hardly flowed.

That is, as shown in FIG. 9, when the gas seal chamber 2 is provided with four baffles 10a, 10b, 10c and 10d, it flows into the gas seal chamber 2 from the pump discharge port 11 through the circulation pipe 12. The pump handling liquid 7 is flowed from the outer diameter side between the baffle plates 10c and 10d toward the inner diameter side, as shown by the arrow in the figure,
Although it flows into the shaft penetrating portion gap 14 between the partition 13 and the rotary shaft 9 and is returned to the pump discharge port 11 for circulation as described above, the circulated pump handling liquid 7 is the baffle plate 10a. , 10d
Between the baffles 10a, 10b, 10b, 10c, and 10a, 10d, since there is almost no flow between the baffles 10a, 10b and between the baffles 10a, 10b. Is not flowing and is almost stagnant, so baffles 10c, 10d
It was found that polymerization or solidification occurred in the pump handling liquid 7 in the gas seal chamber 2 excluding the space. Therefore, the applicant has the idea that the polymerization or solidification of the pump handling liquid 7 in the gas seal chamber 2 can be prevented by causing most of the pump handling liquid 7 in the gas seal chamber 2 to flow without stagnation. .

Based on this idea, the structure of the gas-sealed motor pump of the present invention is such that the gas-sealed chamber is airtightly integrated with the upper side of the pump part, and is axially sealed by a mechanical seal so as to project above the gas-sealed chamber. In a motor pump in which a rotating shaft is connected to a motor unit, an auxiliary pump chamber is provided between the pump unit and the gas seal chamber, and a partition body that partitions the auxiliary pump chamber and the gas seal chamber is provided. An auxiliary impeller is provided in the auxiliary pump chamber by arranging an auxiliary impeller with its suction side facing the shaft penetrating portion gap with the rotating shaft,
The partition body is provided with a plurality of auxiliary pump discharge holes that connect the discharge side of the auxiliary pump portion and the outer diameter side of the gas seal chamber.

(Operation) In the gas-sealed motor pump of the present invention, the pumping liquid in the gas-seal chamber causes the pump handling liquid in the gas-seal chamber to rotate between the partition body and the rotary shaft that partition the auxiliary pump chamber and the gas-seal chamber. The gas is sucked into the auxiliary pump through the gap of the penetrating portion, and is discharged from the discharge side of the auxiliary pump to the outer diameter side of the gas seal chamber through the plurality of auxiliary pump discharge holes formed in the partition body. In almost the entire area of the seal chamber, it flows from the outer diameter side to the inner diameter side and is circulated to the auxiliary pump portion through the shaft penetrating portion gap.

Since most of the pump handling liquid in the gas seal chamber flows due to the circulation of the pump handling liquid, polymerization or solidification due to the stagnation of the pump handling liquid in the gas seal chamber is prevented.

(Example) Next, the Example of this invention is described based on drawing.

In FIG. 1 and FIG. 2, a can motor unit 23 is airtightly integrated with a gas seal chamber 22 above a pump unit 21, and a rotor chamber 24 and a gas seal chamber 22 of the can motor unit 23 are provided. With a canned motor pump whose shafts are mechanically sealed by a mechanical seal 25, a clear liquid 28 sealed in the rotor chamber 24, the upper pot 26 and the heat exchanger 27 is operated by an auxiliary impeller 29 of the canned motor unit to form an upper bearing 30 Lubricate the can gap 33 between the stator can 31 and the rotor can 32.
To cool the stator 34 and the rotor 35, lubricate the lower bearing 36 and the mechanical seal 25, and reach the heat exchanger 27.
A canned motor circulation path is formed, which is cooled by the heat exchanger 27 and is circulated back from the upper pot 26 to the canned motor part auxiliary impeller 29.

Then, the first partition body 38 and the second partition body 39 are sequentially fitted to the lower end portion of the adapter 37 that connects the pump portion 21 and the canned motor portion 23 and serves as the wall body of the gas seal chamber 22, and the bolt The second partition 39 is fastened to the adapter 37 at 40, and the first partition 38 is fixed to the second partition 39 and the adapter.
It is clamped between 37 and the pump casing 41 is attached to the second partition.
39, and is fastened to the adapter 37 with a bolt 43 via a gasket 42, and the gas seal chamber 22 is provided between the mechanical seal 25 and the first partition body 38 and the first partition body 38. An auxiliary pump chamber 44 is formed between the second partition 39 and the pump chamber 45 between the second partition 39 and the pump casing 41.

Further, the impeller 47 attached to the lower end of the rotary shaft 46 is arranged in the pump chamber 45 to construct the pump chamber 21, and the first partition body is constructed.
The auxiliary impeller 49 attached to the rotary shaft 46 is disposed in the auxiliary pump chamber 44 with the suction side 49a facing the shaft penetrating gap 48 between the rotary shaft 46 and the rotary shaft 46. Pump section 50
An auxiliary pump discharge hole 51 for communicating the discharge side 50a of the gas seal chamber 22 with the outer diameter side of the gas seal chamber 22 is formed in the first partition 38, and in the present embodiment, as shown in FIG. 52a, 52b,
One auxiliary pump discharge hole 51 is formed between 52c and 52d.

According to the embodiment configured as described above, the pump handling liquid 53 in the gas seal chamber 22 is generated by the pumping action of the auxiliary pump unit 50.
Is sucked into the auxiliary pump portion 50 through the gap 48 between the first partition body 38 and the rotary shaft 46, and is bored in the first partition body 38 from the discharge side 50a of the auxiliary pump portion 50. The gas is delivered to the outer diameter side of the gas seal chamber 22 through a plurality of auxiliary pump discharge holes 51 and flows from the outer diameter side to the inner diameter side in the gas seal chamber 22 as indicated by an arrow in FIG. It is circulated to the auxiliary pump unit 50 through the through hole gap 48.

As described above, most of the pump handling liquid 53 in the gas seal chamber 22 is circulated by the auxiliary pump unit 50 and flows from the outer diameter side to the inner diameter side in almost the entire area of the gas seal chamber 22 as shown by the arrow. Therefore, polymerization or solidification due to stagnation in the gas seal chamber 22 does not occur, and the pump handling of the portion near the baffles 52a, 52b, 52c and 52d on the outer diameter side of the gas seal chamber 22 is performed. The liquid 53 may be locally affected by the circulation flow and may be in a state close to stagnation.However, the volume of the gas seal chamber 22 is extremely small due to polymerization or solidification. Moreover, after this polymerization or solidification occurs locally, the gas seal chamber
Since there is no stagnant portion of the pump handling liquid 53 at 22, the polymerization or solidification does not proceed any further, and therefore the gas seal chamber
There is no possibility that the liquid level rises due to polymerization or solidification due to the stagnation of the pump handling liquid 53 at 22 and the mechanical seal 25 is damaged and the gas sealing action is impaired.

Further, the auxiliary pump discharge hole 51, which connects the discharge side 50a of the auxiliary pump portion 50 and the outer diameter side of the gas seal chamber 22 to circulate the pump handling liquid 53 in the gas seal chamber 22, is formed in the first partition 38. Therefore, as in the conventional example shown in FIG. 8 and FIG. 9, the pump discharge port 11 is arranged so that a part of the pump handling liquid 7 at the pump discharge port 11 flows into the gas seal chamber 2 and is circulated.
Since the 11 and the gas seal chamber 2 are connected and communicated with each other by the circulation pipe 12, there is a disadvantage that the number of seal points that may cause liquid leakage increases if careless external force is applied during transportation, installation, or inspection. Absent.

In this embodiment, as described above, the pump handling liquid 53 is locally polymerized or solidified in the gas seal chamber 22, and the product does not adhere to the gas seal chamber 22 or a part of the adhered product. Even if it is separated and falls into the pump chamber 45 through the gap 55 between the second partition 39 and the rotary shaft 46 while circulating with the pump handling liquid 53 and is mixed into the pump discharge liquid, The amount is extremely small compared to the conventional examples,
Almost no practical problems occur due to deterioration of the quality of the product produced from the pump handling liquid 53.

However, when the amount of the product mixed in the pump handling liquid 53 is more severely limited, as shown in FIG. 3, the pump handling liquid 53 in the gas seal chamber 22 is prevented from being locally retained. , A large number of auxiliary pump discharge holes 51 are provided on the outer diameter side between the adjacent baffle plates 52a, 52b, 52c and 53d, respectively, or although not shown, a large number of baffle plates are added to the outside between the adjacent baffle plates. One auxiliary pump discharge hole may be provided on each radial side.

The embodiment in which the present invention is applied to the gas seal type canned motor pump in which a plurality of baffle plates are radially arranged in the gas seal chamber to prevent the disturbance of the liquid handled by the pump in the gas seal chamber has been described. As shown in FIG. 5 and FIG. 5, the first partition 38 is integrally provided with a sleeve 38a extending above the gas seal chamber 22, and a through hole 54 is formed in the base of the sleeve 38a to form a gas seal chamber. Of course, it can be applied to a gas seal type canned motor pump configured to prevent disturbance of the pump handling liquid 53 of 22 as well. Applicable to

[Effect of device]

According to the gas seal type motor pump of the present invention, most of the pump handling liquid in the gas seal chamber is circulated by the auxiliary pump portion and flows from the outer diameter side to the inner diameter side in almost the entire area of the gas seal chamber. , No polymerization or solidification due to stagnation in the gas seal chamber occurs, and even if local stagnation causes polymerization or solidification, the volume of the gas seal chamber decreases very little. After polymerization or coagulation occurs locally, there is no stagnation part, so polymerization or coagulation does not proceed any further, and therefore the liquid level rises due to polymerization or coagulation due to stagnation of the pump handling liquid in the gas seal chamber, There is no risk of damaging the mechanical seal and impairing the gas seal function.

Further, as in the conventional example shown in FIGS. 8 and 9,
Since the pump discharge port and the gas seal chamber are connected and circulated by a circulation pipe in order to flow the pump handling liquid in the gas seal chamber, liquid leakage will occur if an external force is inadvertently applied during transportation, installation, or inspection. There is no disadvantage that the number of sealing points that may cause the increase is increased.

[Brief description of drawings]

1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a lateral sectional view taken along the line AA of FIG. 1, and FIG. 3 is a plurality of auxiliary pump discharges between respective baffle plates in the embodiment. FIG. 1 shows a cross-sectional view taken along the line AA of FIG. 1 showing the case where holes are bored, FIG. 4 is a vertical cross-sectional view showing another embodiment of the same as above, and FIG. 5 is a cross-sectional view taken along the line BB of FIG. FIG. 6 is a longitudinal sectional view showing a conventional gas-sealed canned motor pump, FIG. 7 is a transverse sectional view taken along the line CC of FIG.
FIG. 8 is a longitudinal sectional view showing another conventional gas-sealed canned motor pump, and FIG. 9 is a lateral sectional view taken along the line D-D of FIG. 21 …… Pump part, 22 …… Gas seal chamber, 23 …… Canned motor part, 25 …… Mechanical seal, 38 …… First partition, 44 …… Auxiliary pump chamber, 46 …… Rotary shaft, 48… … Axial penetration gap, 49 …… Auxiliary impeller, 49a …… Suction side of auxiliary impeller, 50 …… Auxiliary pump section, 50a …… Discharge side of auxiliary pump section, 51 …… Auxiliary pump discharge hole, 52a, 52b, 52c, 52d ...
… Baffle plate, 53 …… Pump handling liquid, 38a …… Sleeve, 54
…… Through hole.

Claims (1)

[Scope of utility model registration request] 1. A motor in which a gas seal chamber is integrally formed in an airtight manner on the upper side of a pump unit, and a rotary shaft which is axially sealed by a mechanical seal and protrudes above the gas seal chamber is connected to a motor unit. In the pump, an auxiliary pump chamber is provided between the pump portion and the gas seal chamber, and a suction side is provided in a gap between the partition body that partitions the auxiliary pump chamber and the gas seal chamber and the rotary shaft. Auxiliary impeller directed to the above is disposed in the auxiliary pump chamber to construct an auxiliary pump portion, and a plurality of auxiliary pump discharge holes communicating the discharge side of the auxiliary pump and the outer diameter side of the gas seal chamber are provided. A gas-sealed motor pump characterized by being formed in a partition body.