WO2021009823A1

WO2021009823A1 - Underwater aeration mixing device provided with motor cooling function

Info

Publication number: WO2021009823A1
Application number: PCT/JP2019/027821
Authority: WO
Inventors: 育馬尊田
Original assignee: 阪神動力機械株式会社
Priority date: 2019-07-12
Filing date: 2019-07-12
Publication date: 2021-01-21

Abstract

An underwater aeration mixing device that comprises a motor, an impeller that is rotated by being driven by the motor, and a discharge port to discharge a gas-liquid mixed water flow supplied from the impeller, wherein a cooling nozzle is provided so as to branch from the discharge port and a water current is generated on the outer circumference of the motor due to the gas-liquid mixed water flow being sprayed from the cooling nozzle toward the motor. By generating a water current on the outer circumference of the motor, it is possible to efficiently dissipate heat generated by the motor and mitigate motor overheating.

Description

Underwater aeration agitator with motor cooling function

The present invention relates to an underwater aeration stirrer that is installed in a water tank such as a wastewater treatment facility or in a river to aerate and stir the waste water in the water tank and the water in the river.

In order to improve the quality of wastewater in water tanks of wastewater treatment facilities and river water, an underwater aeration stirrer is used that forcibly creates convection with surface water while supplying oxygen to low-rise water. In an underwater aeration agitator, as described in Patent Document 1 below, drainage or the like is generally sucked up from an impeller whose drive source is a motor, mixed with air supplied from an air supply pipe, and discharged. The structure is such that the water is discharged from the outlet to the outside of the underwater aeration agitator.

Japanese Patent No. 32033336

The underwater aeration agitator described in Patent Document 1 has a discharge port for discharging a gas-liquid mixed water flow in the radial direction. When the gas-liquid mixed water flow is discharged from the discharge port, the discharge flow is generated in the radial direction. Due to this discharge flow, a water flow is generated in the water tank, and the gas-liquid mixed water flow is placed on the water flow and diffused to the end of the water tank, and aeration can be reliably performed over a wide range.

In addition, a motor that serves as a rotational drive source for the impeller is provided above the underwater aeration agitator.

Since the purpose of the discharge flow is to diffuse the gas-liquid mixed water flow over as wide a range as possible in a water tank or the like, the discharge flow is generated in a direction away from the underwater aeration agitator. Then, the water flow generated in the water tank by the discharge flow reaches the wall surface or the water surface while moving away from the underwater aeration agitator, and then continues to move back. A part of the water flow eventually reaches the upper part of the underwater aeration agitator, but when a part of the water flow reaches the upper part of the underwater aeration agitator, that is, the peripheral edge of the motor, it is decelerated by the drag force. There is.

-Task-
The inside of the motor generates heat due to operation. By dissipating the heat generated to the outside of the motor, it is possible to reduce the occurrence of an abnormal temperature rise inside the motor.

However, as described above, since the water flow reaching the peripheral edge of the motor is in a state of being decelerated by the drag force, the water flow is not sufficient to promote the heat transfer of the peripheral edge of the motor. Therefore, there is a problem that the heat generated by the motor stays on the periphery of the motor, the insulating material inside the motor deteriorates, and the motor is damaged in a short period of time.

The present invention has been made to solve the above-mentioned conventional problems, and by injecting a gas-liquid mixed water flow to the periphery of the motor to generate a water flow, the heat generated by the motor is efficiently dissipated and the motor is dissipated. It is an object of the present invention to provide an underwater aeration agitator having a motor cooling function capable of alleviating overheating.

In order to achieve the above object, the underwater agitation / stirring device of the present invention includes an underwater agitation device including a motor, an impeller rotated by driving the motor, and a discharge port for discharging a gas-liquid mixed water flow sent from the impeller. In the agitator, the underwater agitation agitator has a cooling nozzle formed so as to branch from the discharge port, and the cooling nozzle injects the gas-liquid mixed water flow toward the motor, and the motor of the agitator. It is characterized in that a water flow is generated on the outer circumference.

According to this specific matter, the gas-liquid mixed water flow sent from the impeller is branched into a discharge port and a cooling nozzle, the gas-liquid mixed water flow is discharged from the discharge port, and the gas-liquid mixed water flow is also injected from the cooling nozzle. Can be done. Then, a gas-liquid mixed water flow injected from the cooling nozzle toward the motor generates a water flow on the periphery of the motor.

According to the underwater aeration agitator of the present invention, the heat generated by the motor can be efficiently dissipated by injecting a water stream, and the overheating of the motor can be mitigated. Therefore, the deterioration of the insulating material due to overheating of the motor can be delayed, and the life of the motor can be extended.

It is a front view which shows the underwater aeration agitator which concerns on one Embodiment of this invention. It is a vertical cross-sectional view which shows the underwater aeration agitator of FIG. It is a top view which shows the underwater aeration agitator of FIG. It is a slope view which shows the cooling nozzle. It is sectional drawing in line AA of FIG. It is sectional drawing in BB line of FIG. It is a graph which shows the surface temperature of a motor.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments.

FIG. 1 is a front view showing an underwater aeration / stirring device 1 according to an embodiment of the present invention. Further, FIG. 2 is a vertical cross-sectional view showing the underwater aeration stirring device 1, and FIG. 3 is a top view showing the underwater aeration stirring device 1.

As shown in FIGS. 1 and 2, the underwater aeration / stirring device 1 has a rotational power mechanism 10 arranged at the upper part with the axis in a vertical state, and below the rotational power mechanism 10 so as to be rotated by the rotational power mechanism 10. It is provided with an impeller 20 attached to the side. The impeller 20 is arranged in the pump casing 30 formed in a cylindrical shape, and a discharge casing 40 provided with a plurality of discharge ports 411 extending in the radial direction is attached to the upper side of the pump casing 30. Hereinafter, each of the above components will be described in detail from the rotational power mechanism 10.

-Rotation drive mechanism-
As shown in FIG. 2, the rotary power mechanism 10 includes a motor 11 whose axis is in a vertical state, and a speed reducer 12 attached to an output shaft extending below the motor 11.

The motor 11 is arranged above the discharge casing 40. A cabtire cable 13 that supplies electric power to the rotational power mechanism 10 is connected above the motor 11.

The speed reducer 12 is arranged in the discharge casing 40 so as to be supported by the discharge casing 40. The output shaft of the speed reducer 12 penetrates the central portion of the discharge casing 40 and reaches the inside of the pump casing 30. An impeller 20 is attached to the output shaft of the speed reducer 12 located in the pump casing 30.

-Imeller-
The impeller 20 is surrounded by a pump casing 30 and has a cylindrical hub 21 attached so that the output shaft of the speed reducer 12 is inserted upward, and a plurality of blades arranged at equal intervals in the circumferential direction of the hub 21. 22 and. The power generated by driving the motor 11 is transmitted to the hub 21 via the output shaft of the motor 11, the speed reducer 12, and the output shaft of the speed reducer 12, so that the impeller 20 rotates. The impeller 20 has a role of sucking water from below the pump casing 30 and sending it into the discharge casing 40 by its rotational operation.

Both the hub 21 and the blade 22 are made of austenitic stainless steel, but the hub 21 and the blade 22 are not limited to this as long as they have excellent durability.

The hub 21 has an opening at the bottom, and an air supply pipe 50 for supplying air into the underwater aeration / stirring device 1 is inserted through the opening. A plurality of air discharge ports 21a are arranged on the upper peripheral surface of the hub 21 at equal intervals in the circumferential direction. The air supplied from the air supply pipe 50 into the hub 21 is discharged into the pump casing 30 through each air discharge port 21a.

Each blade 22 is formed so as to extend in the radial direction from the peripheral surface of the hub 21 with a large pitch angle so as to generate a strong upward water flow by the rotation of the impeller 20.

-Pump casing-
The pump casing 30 has a cylindrical pump casing main body 31 whose diameter gradually increases toward the lower side, and a plurality of legs 32 formed so as to extend below the pump casing main body 31.

The pump casing main body 31 is formed so that the upper surface and the lower surface are open. The outer peripheral surface of the pump casing main body 31 is reinforced by a plurality of reinforcing ribs 31a extending in the vertical direction arranged at equal intervals in the circumferential direction. The pump casing main body 31 is made of a cast iron material having excellent workability, but of course, the pump casing main body 31 is not limited to this.

The legs 32 are arranged at equal intervals in the circumferential direction. The underwater aeration agitator 1 is supported by the legs 32 so as to stand upright in the water tank. For example, the underwater aeration / stirring device 1 is supported by three legs 32, but the number of legs 32 is not limited to this. Further, the length of the leg portion 32 is set so as to secure a sufficient clearance for piping the air supply pipe 50 from the lower part of the pump casing main body 31 to the bottom surface where the submersible aeration / stirring device 1 is installed. ..

-Discharge casing-
The discharge casing 40 is attached to the upper side of the pump casing 30 and is provided with a plurality of discharge ports 411 extending in the radial direction. The discharge casing main body 41 is spaced equal to the circumferential direction. It has a plurality of cooling nozzles 42 arranged at the base end portion, a flange 43 fastened to the pump casing 30, and a hook member 44 to which the hanger 60 is locked.

The discharge casing main body 41 is formed so that the upper surface and the lower surface are open. The discharge casing main body 41 is made of a cast iron material having excellent workability like the pump casing main body 31, but is not limited to this, of course.

Each discharge port 411 is provided to discharge the water sent from the impeller 20 into the discharge casing 40, and is suitable upward with respect to the annular lower guide plate 413 and the lower guide plate 413. It is an opening formed from an annular upper guide plate 412 arranged at intervals and a plurality of partition walls 414 connecting the upper guide plate 412 and the lower guide plate 413.

The lower guide plate 413 has an opening in the axial center portion, and is formed so as to incline downward in order toward the outside at an angle of about 5 to 40 degrees.

The upper guide plate 412 has a through hole in the center, and is arranged above the lower guide plate 413 substantially in parallel with a certain interval. The inner peripheral side portion of the upper guide plate 412 is gently curved in an arc shape so as to go downward, and the inner peripheral edge thereof is concentrically located in the opening of the lower guide plate 413.

As shown in FIG. 3, the upper guide plate 412 is divided into six equal parts by six pairs of partition walls 414 extending in the radial direction at the six equal parts in the circumferential direction. The number of divisions may be appropriately changed depending on the model and the like.

Each partition wall 414 is formed by being integrally bent with the upper guide plate 412 and bent downward, and the lower edge is formed so as to abut against the upper surface of the lower guide plate 413. A connecting portion 415 for connecting the inner peripheral side portions of the partition walls 414 is provided on the inner peripheral side portion of the partition wall 414. The connecting portion 415 is formed so as to be curved in an arc shape with a relatively large curvature so as to project toward the inner peripheral side, and to be inclined at about 30 to 60 degrees so as to be located upward toward the inner peripheral side. To.

Between each partition wall 414, there is a guide groove 416 that is open upward and in the radial direction and extends in the radial direction.

The lower end edge of the truncated cone-shaped stay 417 is supported by the curved portion on the inner peripheral side of the upper guide plate 412. The stay 417 is concentric with the through hole of the upper guide plate 412, and is formed so that the peripheral surface is inclined at about 45 degrees so as to be continuous with the connecting portion 415 of the partition wall 414. The upper surface and the lower surface of the stay 417 are opened, and the speed reducer 12 is incorporated between the inner peripheral side portion of the upper guide plate 412 and the stay 417.

FIG. 4 is a perspective view showing the cooling nozzle 42. FIG. 5 is a radial cross-sectional view of the cooling nozzle 42 attached to the underwater aeration / stirring device 1, and FIG. 6 is a circumferential cross-sectional view of the cooling nozzle 42 attached to the underwater aeration / stirring device 1. It is a figure.

As shown in FIG. 3, the cooling nozzle 42 is arranged on the proximal end side of the surface of the upper guide plate 412 at a position divided into three equal parts in the circumferential direction. By arranging the cooling nozzle 42 on the upper surface of the upper guide plate 412, a part of the water flowing between the upper guide plate 412 and the lower guide plate 413 is branched to the cooling nozzle 42 and discharged from the discharge port 411. It is injected as an injection flow from the cooling nozzle 42 separately from the discharge flow. The cooling nozzle 42 is made of austenitic stainless steel, but is not limited to this as long as it has excellent durability.

As shown in FIG. 4, the cooling nozzle 42 is provided so as to face the nozzle body 421 formed so that the upper end of the cylinder is gently curved so as to form 180 degrees in the radial direction of the nozzle body 421. It has two flanges 422, an injection port 423 formed by the nozzle body 421, and a fastening hole 424 provided so as to penetrate in the thickness direction of the flange 422.

As shown in FIGS. 4 and 5, the nozzle body 421 has a cylindrical lower portion and an upper portion formed so that the central axis of the cylinder is gently curved to a predetermined angle so as to move away from the vertical axis. Become. That is, the upper end of the nozzle body 421 is opened so as to be inclined in the radial direction, and the lower end of the nozzle body 421 is opened in the vertical axis direction.

The angle at which the upper part of the nozzle body 421 is curved is set so that the water ejected from the injection port 423, which will be described later, faces the direction of the motor 11 arranged on the upper part of the underwater aeration stirring device 1.

As shown in FIGS. 4, 5 and 6, a fitting portion 421a for fitting into a fitting hole previously provided in the upper guide plate 412 is provided at the lower end of the lower portion of the nozzle body 421. The outer circumference of the fitting portion 421a is formed to be smaller than the outer circumference of the lower portion of the nozzle body 421 in order to avoid stress concentration at the connection portion between the flange 422 and the nozzle body 421, which will be described later.

As shown in FIGS. 4 and 6, two flanges 422 are provided on the outer peripheral edge of the nozzle body 421 above the fitting portion 421a. One of the flanges 422 is horizontally attached to the outer peripheral edge of the nozzle body 421 at a position of 90 degrees clockwise with respect to the direction in which the opening at the upper end of the nozzle body 421 is inclined in the radial direction. The other end of the flange 422 is horizontally attached to the outer peripheral edge of the nozzle body 421 at a position of 270 degrees clockwise with respect to the direction in which the opening at the upper end of the nozzle body 421 is inclined in the radial direction. That is, the two flanges 422 are provided facing each other so as to form 180 degrees in the radial direction. The flange 422 is formed in a substantially rectangular shape whose width is set smaller than the outer circumference of the lower portion of the nozzle body 421. The two corners located at the tip of the flange 422 are chamfered. The length of the flange 422 is set by the position of the fastening hole 424 described later.

The injection port 423 is an opening formed by the nozzle body 421 as shown in FIGS. 4, 5 and 6. A part of the water sent into the discharge casing 40 by the impeller 20 rides on the water flow due to the rotation of the impeller 20 and enters the nozzle body 421, and is directly ejected from the injection port 423 to the outside of the underwater aeration stirring device 1. .. Since the cross-sectional area of the nozzle body 421 is significantly smaller than the cross-sectional area of the path including the upper guide plate 412 and the lower guide plate 413 through which water has passed so far, water passes through the nozzle body 421. It is accelerated and injected from the injection port 423.

As shown in FIGS. 4 and 6, the fastening holes 424 are two bolt fastening holes used for fixing the cooling nozzle 42 to the surface of the upper guide plate 412, one in the thickness direction of each flange 422. It was penetrated. The pitch between the fastening holes 424 is set so as to correspond to the nozzle fixing portion 412a provided in advance on the upper guide plate 412. The nozzle fixing portion 412a of the upper guide plate 412 is a through hole, and the cooling nozzle 42 is attached to the surface of the upper guide plate 412 by penetrating the bolt through the fastening hole 424 and fastening the flange 422 to the nozzle fixing portion 412a. Fix it. The nozzle fixing portion 412a is not limited to the above structure, and may be configured as a stud, for example, the stud may be passed through the fastening hole 424 and the flange 422 may be fastened with a nut.

The cooling nozzle 42 injects a part of the water flowing between the upper guide plate 412 and the lower guide plate 413 from the cooling nozzle 42 separately from the discharge flow that branches to the cooling nozzle 42 and is discharged from the discharge port 411. Since it is sufficient if the cooling nozzle 42 can be injected as a flow, the shape and structure of the cooling nozzle 42 are not limited to the above, and may be complicated, for example. Further, the cooling nozzle 42 may be a separate component attached to the upper guide plate 412 as described above, or may be integrally molded with the upper guide plate 412.

As shown in FIG. 2, the flange 43 is provided on the inner peripheral edge of the lower surface open portion of the discharge casing main body 41 over the entire circumference. The flange 43 is placed on the upper surface of the pump casing main body 31 over the entire circumference, and is fixed to the upper surface of the pump casing main body 31 with bolts or the like.

As shown in FIG. 3, hook members 44 are attached to the upper surfaces of the upper guide plates 412 located on one side of the guide grooves 416 arranged every other in all the guide grooves 416. As shown in FIGS. 1 and 2, the lower end of the hanger 60 is locked to each hook member 44. A wire rope or the like is locked to the hanger 60, and the entire underwater aeration / stirring device is lowered inside the water treatment reaction tank or the like and installed on the bottom surface thereof.

In the above embodiment, the discharge casing 40 is attached to the upper side of the pump casing 30, but in the present invention, the discharge casing 40 is attached to the lower side of the pump casing 30 and water is attached from the upper side of the pump casing 30. May be sucked and discharged from the lower side. Further, in the above embodiment, the motor 11 is arranged on the upper side of the discharge casing 40 and the cooling nozzle 42 is opened upward toward the motor 11, but in the present invention, the motor 11 is placed on the discharge casing. It may be arranged on the lower side of the 40 and the cooling nozzle 42 may be opened downward toward the motor 11.

Based on the above embodiment, the present invention will be described in more detail together with an example of using the underwater aeration / stirring device according to the present invention. However, the present invention is not limited to the following examples.

The underwater aeration / stirring device 1 described above is used in a state of being installed on the bottom surface of a water treatment reaction tank or the like. By driving the motor 11 of the rotation drive mechanism 10, the impeller 20 arranged in the pump casing main body 31 rotates. By the rotation of the impeller 20, water is sucked into the pump casing main body 31 through the bottom surface, and flows upward in the pump casing main body 31.

At this time, the air supplied from the air supply pipe 50 is discharged from each air discharge port 21a provided on the upper peripheral surface of the hub 21. Then, the air discharged from each air discharge port 21a is diffused and mixed in the water flowing upward through the pump casing main body 31. Since each air discharge port 21a rotates coaxially with the blade 22, the air discharged from each air discharge port 21a is finely sheared by the rotational action to become fine bubbles, and the oxygen in the bubbles is efficiently in the water. Is dissolved in.

In this way, the water in which the fine bubbles are diffused rides on the water flow generated by the impeller 20 and flows upward in the pump casing main body 31, and the upper guide plate 412 and the lower guide plate 413 of the discharge casing 40 Introduced during. A part of the water is branched into three cooling nozzles 42 provided at the base end of the upper guide plate 412, and while riding on the water flow generated by the impeller 20, all the cooling nozzles 42 head toward the motor 11. Is injected. The other part of the water is bent outward in the radial direction by the upper guide plate 412, and is discharged diagonally downward in the radial direction from all the discharge ports 411 partitioned by the partition wall 414.

The injection flow injected from each cooling nozzle 42 generates a water flow in the direction of the motor 11. A water flow is generated on the outer circumference of the motor 11 by the injection flow injected from each cooling nozzle 42, and the water flow can efficiently dissipate the heat staying on the outer circumference of the motor 11 and alleviate the overheating of the motor. .. Therefore, it is possible to delay the deterioration of the insulating material due to overheating of the motor and extend the life of the motor.

As described above, the cooling nozzle 42 branches a part of the water introduced between the upper guide plate 412 and the lower guide plate 413 into the cooling nozzle 42 provided at the base end of the upper guide plate 412. The structure is such that the water flow generated by the impeller 20 is used to inject water from the cooling nozzle 42 toward the motor 11. Therefore, the cooling nozzle 42 can inject water even though it has a simple structure that does not have a separate pump or the like for injecting water from the cooling nozzle 42.

Since the water discharged from all the discharge ports 411 flows along the bottom of the water treatment reaction tank and the like, the bottom of the water treatment reaction tank and the like is surely agitated. Moreover, since the water and air discharged from the discharge port 411 are efficiently mixed with each other, the entire water treatment reaction tank is efficiently and reliably aerated.

<Temperature measurement experiment>
The internal temperature of the motor 11 and the surface temperature of the motor 11 were measured using the above-mentioned underwater aeration stirring device 1. The internal temperature of the motor 11 and the surface temperature of the motor 11 were measured before the cooling nozzle 42 was attached to the underwater aeration stirring device 1 and after the cooling nozzle 42 was attached to the underwater aeration stirring device 1, respectively.

The internal temperature of the motor 11 is measured by measuring the coil temperature by the resistance method, and is 1 each before the cooling nozzle 42 is attached to the underwater aeration stirring device 1 and after the cooling nozzle 42 is attached to the underwater aeration stirring device 1. Measured times.

The surface temperature of the motor 11 was measured by mounting a resistance temperature sensor made of Pt100 on the surface of the motor 11 and measured every 10 minutes.

Table 1 shows the measurement results of the internal temperature of the motor 11 of the underwater aeration stirring device 1. The internal temperature of the motor 11 before attaching the cooling nozzle 42 to the underwater aeration stirring device 1 was 91.6 degrees, whereas the inside of the motor 11 after attaching the cooling nozzle 42 to the underwater aeration stirring device 1 The temperature was 52.3 degrees. That is, the internal temperature of the motor 11 was lowered by 39.3 degrees by attaching the cooling nozzle 42.

FIG. 7 is a graph showing the surface temperature of the motor 11. As is clear from this graph, it can be seen that in the underwater aeration agitation device 1 to which the cooling nozzle 42 is attached, the increase in the surface temperature of the motor 11 is effectively suppressed as compared with the case where the cooling nozzle 42 is not attached.

From the above results, it can be concluded that the water flow generated on the outer circumference of the motor 11 due to the injection flow injected from the cooling nozzle 42 promotes heat dissipation of the motor and suppresses overheating of the motor.

The above embodiment is an example in all respects and does not serve as a basis for a limited interpretation. Therefore, the technical scope of the present invention is not construed solely by the above-described embodiments, but is defined based on the description of the claims. It also includes all changes within the meaning and scope of the claims.

1 Submersible air exposure agitator 10 Rotating power mechanism 11 Motor 12 Reducer 13 Cabtire cable 20 Impeller 21 Hub 21a Air discharge port 22 Blade 30 Pump casing 31 Pump casing body 31a Reinforcing rib 32 Leg 40 Discharge casing 41 Discharge casing body 411 Discharge Outlet 412 Upper guide plate 412a Nozzle fixing part 413 Lower guide plate 414 Partition 415 Connecting part 416 Guide groove 417 Stay 42 Cooling nozzle 421 Nozzle body 421a Fitting part 422 Flange 423 Injection port 424 Fastening hole 43 Flange 50 Air supply pipe 60 Hanger

Claims

In an underwater aeration / stirring device including a motor, an impeller rotated by driving the motor, and a discharge port for discharging a gas-liquid mixed water flow sent from the impeller.
The underwater aeration agitator has a cooling nozzle formed so as to branch from the discharge port.
The cooling nozzle is an underwater aeration agitator that injects the gas-liquid mixed water flow toward the motor to generate a water flow on the outer periphery of the motor.