JP7132877B2 - horizontal shaft pump - Google Patents

Description

The present invention relates to horizontal shaft pumps.

Patent document 1 includes a pump casing, an auxiliary pipe connected to the top of the pump casing, a vacuum pump interposed in the auxiliary pipe, and a steam separator interposed upstream of the vacuum pump in the auxiliary pipe. A horizontal shaft pump is disclosed.

Japanese Patent No. 5364043

In the horizontal shaft pump of Patent Document 1, the vacuum pump is driven at startup, and the air-water separator is provided on the upstream side of the vacuum pump, so that only the air in the pump casing can be efficiently discharged, and the drainage operation can be performed. . However, if an air suction vortex is generated in the water suction tank during the water discharge operation, the air that hinders the water suction is sucked in continuously or intermittently. There is

An object of the present invention is to improve the operation characteristics of a horizontal shaft pump during drainage.

According to one aspect of the present invention, there is provided a pump casing having a suction port arranged in a suction tank and extending horizontally above the suction port; a first end located within the pump casing; and the pump casing. a main shaft having an outer second end and rotatably arranged in the pump casing so as to extend horizontally; an impeller arranged on the first end side of the main shaft; an auxiliary pipe connected to the upper part of the upstream side of the impeller; an auxiliary pump interposed in the auxiliary pipe for sucking air in the pump casing; a steam separator for separating air and water flowing into the auxiliary pipe; a full water sensor for detecting that the pump casing is filled with water; and driving the impeller and the auxiliary pump. and a control unit for continuing to drive the impeller and the auxiliary pump even after the full-water sensor detects the full-water level.

According to this horizontal shaft pump, the air in the pump casing is discharged through the auxiliary pipe by driving the auxiliary pump at startup, and water flows into the pump casing. Water gradually enters the auxiliary pipe together with air, but the air and water are separated by the steam separator and only the air is discharged through the auxiliary pipe. Therefore, the inside of the pump casing can be efficiently filled with water, and the drainage operation can be started. In addition, since the auxiliary pump continues to be driven even after the full-water level sensor detects that the water level is full, air that has flowed into the pump casing is discharged through the auxiliary pipe by the suction of the auxiliary pump when an air suction vortex occurs. Therefore, it is possible to effectively suppress collision of air against the impeller during drainage, thereby improving the operating characteristics of the horizontal shaft pump. In addition, since the water can be drained to the water level at which the air suction vortex is generated, the water in the suction tank can be drained to a low water level.

The steam separator is a cyclone separator that separates air and water by swirling. According to this aspect, air and water can be separated without using an extra power source (pump) or the like, and only the air can be reliably discharged downstream through the auxiliary pipe.

The cyclone separator has a suction port that opens inside the pump casing and a discharge port that opens on the side of the auxiliary pipe. The opening area of the suction port is larger than the opening area of the discharge port. have a department. According to this aspect, since the discharge pressure of the water flowing into the cyclone separator can be increased, a swirl force can be effectively applied, and air and water can be reliably separated.

A transmission is provided for transmitting the power of the prime mover to the rotating shaft of the main shaft and the auxiliary pump, and the rotating speed of the rotating shaft by the transmission is faster than the rotating speed of the main shaft by the transmission. According to this aspect, since the rotation shaft of the auxiliary pump is rotated at a higher speed than the main shaft, air can be reliably discharged through the auxiliary pipe, and the size of the auxiliary pump can be reduced.

A clutch is provided on the rotary shaft and switches between a connected state in which the power of the prime mover can be transmitted to the auxiliary pump and a disconnected state in which the power of the prime mover cannot be transmitted to the auxiliary pump. According to this aspect, the driving and stopping of the auxiliary pump can be switched according to the internal and external conditions of the pump casing.

Specifically, a valve connected to the pump casing and capable of adjusting an outflow rate from the pump casing to the downstream side is provided, and the control unit reduces the outflow rate to a first flow rate or less determined by the valve. When adjusting, the clutch is switched from the connected state to the disconnected state. This control is executed, for example, in an emergency when the water level on the downstream side of the pump casing suddenly rises. According to this aspect, the valve is throttled and the drive of the auxiliary pump is stopped, so the discharge pressure of the horizontal shaft pump increases. Therefore, since the water in the water suction tank can be reliably discharged to the downstream side, the overflow of the water suction tank can be prevented.

Said auxiliary pump is a self-priming pump with a rotatable impeller. According to this aspect, the air in the pump casing can be discharged through the auxiliary pipe at the time of starting, and the air and water in the pump casing can be discharged through the auxiliary pipe at the time of draining after the water is full.

In the horizontal shaft pump of the present invention, since the auxiliary pump continues to be driven when the water is drained after the detection of full water, the air contained in the air suction vortex can be discharged through the auxiliary pipe. Therefore, it is possible to effectively suppress collision of air against the impeller during drainage, thereby improving the operating characteristics of the horizontal shaft pump.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing of the horizontal shaft pump which concerns on 1st Embodiment of this invention. FIG. 2 is a partially enlarged view of FIG. 1; Sectional drawing of a steam-water separator. The figure which shows the flow-head curve by the horizontal shaft pump of 1st Embodiment. 4 is a flowchart showing activation processing by a control unit; 4 is a flowchart showing waste water treatment by the control unit; 4 is a flowchart showing stop processing by a control unit; 9 is a flow chart showing drainage processing by the control unit of the horizontal shaft pump of the second embodiment. 9 is a flowchart showing emergency processing in FIG. 8;

Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 shows a horizontal shaft pump 10 according to a first embodiment of the invention. The horizontal shaft pump 10 includes a pump casing 12, a main shaft 20, and an impeller (main impeller) 22, and drains rainwater or the like that has flowed into the suction tank 1 downstream. Since the impeller 22 is arranged above the water surface of the suction tank 1, the horizontal shaft pump 10 is preferably used in cold regions where water freezes.

The horizontal shaft pump 10 is provided with an auxiliary device 25 for discharging the air and water inside the pump casing 12 separately from the main drainage path. By driving the auxiliary device 25 when starting the horizontal shaft pump 10, the air in the pump casing 12 is discharged and water flows into the pump casing 12 (starting process). When the inside of the pump casing 12 is filled with water (full water), normal drainage operation is started (drainage treatment). In this embodiment, by changing the period during which the auxiliary device 25 is driven, the operation characteristics during drainage are improved.

The pump casing 12 includes a vertically upwardly extending suction bell 13 , a bent elbow 14 connected to the upper end of the suction bell 13 , and a vane casing 15 connected to the downstream end of the bent elbow 14 . The suction bell 13 has a conical cylindrical shape that gradually expands downward, and a suction port 13a at the lower end thereof is arranged at a predetermined distance from the bottom of the suction tank 1 . The bent elbow 14 is a bent tube whose central axis is bent 90 degrees, and has a through portion 14 a for passing the main shaft 20 through at a position corresponding to the axis of the vane casing 15 . The vane casing 15 has a tubular shape that bulges outward in the radial direction so as to form a substantially elliptical shape, and extends horizontally above the suction port 13a. A bearing casing 15b is provided inside the vane casing 15 via a guide vane 15a, and an underwater bearing 16 that rotatably supports the main shaft 20 is provided in the bearing casing 15b.

A water pipe 17 is connected to a vane casing 15, which is the downstream end of the pump casing 12, and this water pipe 17 is piped to a discharge water tank (not shown) on the downstream side. The water pipe 17 is provided with a discharge valve 18 which can be switched between an open state in which the pump casing 12 and the discharge water tank are communicated and a closed state in which the communication between the pump casing 12 and the discharge water tank is cut off. For the discharge valve 18, a flow control valve is used that can steplessly adjust the amount of flow downstream from the pump casing 12 by changing the opening area (throttle opening).

The main shaft 20 is arranged to pass through the through portion 14a of the pump casing 12 so as to extend in the horizontal direction. The space between the main shaft 20 and the through portion 14a is liquid-tightly sealed by a shaft sealing device. The main shaft 20 has a first end 20a located within the pump casing 12 and is rotatably supported in the underwater bearing 16. As shown in FIG. Further, the main shaft 20 has a second end 20b located outside the pump casing 12, and a prime mover 51, which will be described later, is mechanically connected to the second end 20b.

The impeller 22 is arranged on the first end 20a side of the main shaft 20 so as to be adjacent to the upstream side of the bearing casing 15b. When the main shaft 20 is rotated by driving the prime mover 51, the impeller 22 rotates together with the main shaft 20, sucks the water in the suction tank 1 into the pump casing 12 through the suction port 13a, and discharges it downstream. When the drive of the prime mover 51 is stopped (first water level WL1 in FIG. 1), the impeller 22 is not submerged in the water in the water suction tank 1 at all.

The auxiliary device 25 is provided for sucking up water at a first water level WL1 lower than the impeller 22 into the pump casing 12 to perform a drain operation. The auxiliary device 25 includes an auxiliary pipe 27 , an auxiliary pump 33 , and a steam separator 42 . By driving the auxiliary pump 33 , the air in the pump casing 12 is discharged through the auxiliary pipe 27 and the water in the suction tank 1 is discharged. is sucked into the pump casing 12 . As will be described in detail later, in the present embodiment, the auxiliary pump 33 is also driven in the drainage process that follows the activation process.

The auxiliary pipe 27 includes a first pipe 28 connected to the upper portion of the pump casing 12 and a second pipe 29 connected to the first pipe 28 via the auxiliary pump 33 . The first pipe 28 is connected to the connecting portion 14b of the bent elbow 14 located upstream of the impeller 22 . Referring to FIG. 2, the first pipe 28 includes an ascending portion 28a extending vertically upward from the pump casing 12, a curved portion 28b continuing from the upper end of the ascending portion 28a and curved 180 degrees, and a curved portion 28b continuing to the curved portion 28b. A descending portion 28c extending vertically downward and a connecting portion 28d connected to the auxiliary pump 33 continuously from the lower end of the descending portion 28c are provided. Referring to FIG. 1, the second pipe 29 is an L-shaped pipe, and includes a vertical pipe portion 29a extending vertically upward from the discharge portion 35b of the auxiliary pump 33 and a horizontal pipe portion 29a continuously extending from the upper end of the vertical pipe portion 29a. and a horizontal pipe portion 29b. The horizontal pipe portion 29b is arranged above the curved portion 28b.

A water pipe 30 is connected to a second pipe 29, which is the downstream end of the auxiliary pipe 27, and this water pipe 30 is piped to a discharge water tank on the downstream side. The water pipe 30 is provided with a discharge valve 31 that can be switched between an open state in which the auxiliary pump 33 and the discharge water tank are communicated and a closed state in which the communication between the auxiliary pump 33 and the discharge water tank is cut off. The discharge valve 31 is an on-off valve that can be switched between a fully open state and a fully closed state, but a flow control valve similar to the discharge valve 18 may be used. The discharge side end of the water pipe 30 may be connected to the downstream side of the discharge valve 18 in the water pipe 17 .

The auxiliary pump 33 is interposed between the first pipe 28 and the second pipe 29 that constitute the auxiliary pipe 27 and automatically performs a water priming action by itself to suck the air and water in the pump casing 12 . It is a self-priming pump for Specifically, as shown in FIG. 2, the auxiliary pump 33 includes a casing 35, a rotating shaft 38, and an impeller (auxiliary impeller) 40, and discharges air and water sucked from the pump casing 12 to a discharge water tank.

The casing 35 includes a suction portion 35a connected to the connection portion 28d of the first pipe 28, a discharge portion 35b connected to the vertical pipe portion 29a of the second pipe 29, and a passage portion 35c communicating these. A check valve 36 for preventing backflow to the suction portion 35a (first pipe 28) is provided in the passage portion 35c. Between the passage portion 35c and the discharge portion 35b, a rectifying plate 35d that guides the air and water that have flowed into the passage portion 35c from the suction portion 35a to the impeller 40 is provided. Further, the casing 35 includes a bearing portion 35f partitioned by a partition wall 35e outside the passage portion 35c. A recess 35g in which the impeller 40 is arranged is provided in the partition wall 35e so as to be recessed toward the bearing portion 35f.

The rotary shaft 38 is arranged in the bearing portion 35f so as to extend parallel to the main shaft 20. As shown in FIG. A first end 38a of the rotary shaft 38 penetrates the partition wall 35e and is arranged in the passage portion 35c. A second end 38b of the rotating shaft 38 is arranged outside the bearing portion 35f, and the prime mover 51 is mechanically connected to the second end 38b.

The impeller 40 is arranged at the first end 38a of the rotating shaft 38 so as to be positioned inside the passage portion 35c (recess 35g). As the rotating shaft 38 rotates, the impeller 40 sucks fluid (at least one of air and liquid) from the axial direction and delivers it radially. Specifically, when the inside of the pump casing 12 is not filled with water, air is sucked and sent downstream, while when the inside of the pump casing 12 is filled with water, water is sucked and sent downstream. Send to The check valve 36 arranged at the outlet of the suction portion 35a is opened by air pressure and water pressure from the suction portion 35a.

After the water is discharged by the impeller 40 (drainage treatment), when the driving of the impeller 40 is stopped (stopping process), the water in the ascending portion 28a located upstream of the curved portion 28b of the auxiliary pipe 27 is discharged into the pump casing 12. (see fourth water level WL4 in FIG. 1). On the other hand, water in the descending portion 28c located downstream of the curved portion 28b, in the casing 35, and in the lower portion of the vertical pipe portion 29a (up to approximately the same position as the upper end of the descending portion 28c) flows back into the pump casing 12. It is retained (priming) without being drained or discharged downstream. This priming allows the auxiliary pump 33 to evacuate air on the next start-up.

The air-water separator 42 is provided on the upstream side of the auxiliary pump 33 in the first pipe 28 and separates air and water flowing into the auxiliary pipe 27 . Specifically, the steam separator 42 is arranged in a bulging portion 28e provided at the end of the first pipe 28 on the pump casing 12 side. The bulging portion 28 e has a straight pipe shape with a diameter larger than that of the other portion of the first pipe 28 , and is liquid-tightly connected to the connecting portion 14 b of the bent elbow 14 .

Referring to FIGS. 2 and 3, the air-water separator 42 is a cyclone separator that separates the air and water that have flowed into the auxiliary pipe 27 by swirling. A cylindrical container 46 is provided.

The partition plate 43 has an outer shape that is liquid-tightly attached to the opening of the connection portion 14b, and includes a conical inflow portion (cone) 44 that allows the inside of the pump casing 12 and the inside of the container 46 to communicate with each other, and the inside of the pump casing 12 and the container. 46 and a circulation hole 45 for communicating with the outside. The inflow portion 44 has a suction port 44a that opens inside the pump casing 12 and a discharge port 44b that opens inside the container 46 (on the side of the auxiliary pipe 27). is also big. The suction port 44a is located farther from the impeller 22 than the discharge port 44b. When the pump casing 12 is viewed from the side (the state shown in FIG. 1), the axis from the suction port 44a to the discharge port 44b runs along the water flow in the pump casing 12, and the container 46 moves closer to the impeller 22. sloping upwards towards The circulation hole 45 has an oval shape and is provided in the pump casing 12 so as to be positioned in a lower pressure region than the suction port 44a. That is, in the pump casing 12 during drainage, the pressure P1 in the area where the suction port 44a is located is higher than the pressure P2 in the area where the return hole 45 is located (P1>P2).

The container 46 has a conical cylindrical shape in which the opening area of the upstream end portion 46a liquid-tightly arranged with respect to the partition plate 43 is larger than the opening area of the downstream end portion 46b opened in the bulging portion 28e. be. A partition plate 43 blocks the inside of the upstream end portion 46a except for the inflow portion 44, and when viewed from the direction in which the axis of the container 46 extends, the axis of the inflow portion 44 is in contact with the inner peripheral surface thereof. The height from the bottom of the suction tank 1 to the upstream end 46a is lower than the upper top of the vane casing 15, which is the highest position of the pump casing 12 (see second water level WL2 in FIG. 1). The height of the downstream end 46b is also high (see the third water level WL3 in FIG. 1). As shown most clearly in FIG. 3, a supplemental air space 47 capable of storing air is provided between the inner peripheral surface of the bulging portion 28e and the outer peripheral surface of the container 46. A circulation hole 45 is provided so as to be positioned within the space 47 .

In the steam separator 42 configured in this manner, water flows together with air before the inside of the pump casing 12 is filled with water (state of WL2 or more and less than WL3) at startup. Since the axis of the inflow portion 44 is in contact with the inner peripheral surface of the container 46 and the opening area of the discharge port 44b is smaller than the opening area of the suction port 44a, the fluid flows into the container 46 in a pressurized state. Water, which is heavier than air, spirally swirls along the inner peripheral surface of the container 46 in a state where the circumferential velocity is increased toward the downstream end 46b (swirling flow), and the air flows in the container 46. They gather at the center and go to the downstream end 46b. The separated air flows out from the downstream end 46 b into the supplemental air space 47 and is discharged to the second pipe 29 through the first pipe 28 by the suction force of the auxiliary pump 33 . On the other hand, when the water flows out from the downstream end 46b into the supplemental air space 47, the water is decelerated, drops by its own weight, and returns into the pump casing 12 through the return hole 45. As shown in FIG.

As shown in FIG. 1 , the horizontal shaft pump 10 includes a drive device 50 for rotationally driving the main shaft 20 and the rotary shaft 38 . The driving device 50 includes one prime mover 51 , a transmission 52 for transmitting the power of the prime mover 51 to the main shaft 20 and the rotating shaft 38 , and a clutch 56 for switching the connection state between the prime mover 51 and the rotating shaft 38 .

A well-known diesel (internal combustion) engine driven by light oil, heavy oil, or the like is used as the prime mover 51 . However, the prime mover 51 may be an electric motor, and can be changed according to the environment in which the horizontal shaft pump 10 is installed.

The transmission 52 includes a driving gear 53 connected to the output shaft 51a of the prime mover 51, a first driven gear 54 connected to the second end 20b of the main shaft 20, and a second end 38b of the rotating shaft 38. 2 driven gear 55 is provided. Helical gears are used for these gears 53 to 55 , and the gear ratio of the second driven gear 55 to the drive gear 53 is higher than the gear ratio of the first driven gear 54 to the drive gear 53 . That is, the number of revolutions per unit time of the rotating shaft 38 driven by the second driven gear 55 is made greater than the number of revolutions per unit time of the main shaft 20 driven by the first driven gear 54, and the rotational speed of the rotating shaft 38 is increased to that of the main shaft 20. Faster than the rotation speed.

The clutch 56 is interposed on the rotary shaft 38 and switches between a connected state in which the power of the prime mover 51 can be transmitted to the auxiliary pump 33 and a disconnected state in which the power of the prime mover 51 cannot be transmitted to the auxiliary pump 33 . For example, the clutch 56 includes a pair of clutch plates that can move toward and away from the rotating shaft 38 along the axial direction. If present, the type of clutch 56 can be changed as desired.

Continuing to refer to FIG. 1, the horizontal shaft pump 10 includes a control section 58 for opening and closing the discharge valves 18 and 31, driving and stopping the prime mover 51, and switching the clutch 56. As shown in FIG. The controller 58 is composed of a single or multiple microcomputers and other electronic devices. The control unit 58 drives the prime mover 51 based on starting conditions such as the water level in the suction tank 1 and rainfall information in the surrounding area, and controls the amount of water in the pump casing 12, the water level in the suction tank 1, and the water level in the discharge tank. Switch the operation state in wastewater treatment based on various conditions such as.

A full water sensor 60 is arranged at the top of the vane casing 15, which is the highest position, in order to detect the amount of water in the pump casing 12, specifically when the pump casing 12 is filled with water. As the full water sensor 60, a water level sensor that detects the water level in the pump casing 12, or a pressure sensor that detects pressure (discharge pressure) that increases or decreases according to an increase or decrease in the amount of water can be used.

The control unit 58 first executes a start-up process for the horizontal shaft pump 10 when a predetermined start condition is established, executes a drainage process when the pump casing 12 is filled with water, and executes a stop condition set during the drainage process. is established, stop processing is executed. The main shaft 20 (impeller 22) and the rotary shaft 38 (auxiliary pump 33) are rotationally driven in the start-up process, and the drive of the main shaft 20 and the rotary shaft 38 is continued in the drainage process. In other words, the auxiliary pump 33 continues to be driven even after the full water sensor 60 detects full water. In addition, in wastewater treatment, continuous operation can be performed without overheating, noise, vibration, etc., and when the mini-flow execution condition of discharging water at a discharge rate smaller than the normal discharge rate is satisfied, the opening of the discharge valve 18 is increased. change.

Next, control by the control unit 58 will be specifically described with reference to FIGS. 5 to 7. FIG.

In the start-up process, the control unit 58 drives the auxiliary pump 33 to discharge the air in the pump casing 12 to suck the water in the suction tank 1 and fill the pump casing 12 with water. Since the impeller 22 idles at the time of starting, the starting torque is small and the motor starting current can be suppressed.

As shown in FIG. 5, the control unit 58 waits until the activation condition is satisfied in step S1, and when the activation condition is satisfied, switches the discharge valve 31 of the auxiliary device 25 from the closed state to the open state in step S2. Further, the prime mover 51 is driven in step S3, and the clutch 56 is connected in step S4. As a result, the power of the prime mover 51 is transmitted to the main shaft 20 and the rotary shaft 38 via the transmission 52, and the impeller 22 of the horizontal shaft pump 10 itself and the impeller 40 of the auxiliary device 25 rotate. In this state, the discharge valve 18 of the horizontal shaft pump 10 itself is fully closed (step S22 to be described later).

Air in the pump casing 12 is discharged by the rotation of the impeller 40, water in the suction tank 1 is sucked up from the suction port 13a, and the water level in the pump casing 12 rises from WL1 shown in FIG. When the water level in the pump casing 12 rises to WL2 shown in FIG. 1, water begins to flow into the auxiliary pipe 27 together with air. Then, as described above, the air and water are separated by the steam separator 42, the air is discharged through the auxiliary pipe 27, and the water is returned into the pump casing 12.

The controller 58 waits until the full water sensor 60 detects full water in step S5. When the water level inside the pump casing 12 rises to WL3 shown in FIG. 1, it is detected that the inside of the pump casing 12 is full of water. As a result, the controller 58 fully opens the discharge valve 18 (100% opening) in step S6. After that, in step S7, it waits until the rated water discharge (discharge amount) is detected based on the detection result of the pressure sensor 62 on the side of the discharge water tank. As a result, the controller 58 shifts to wastewater treatment.

In the wastewater treatment, the control unit 58 operates with the discharge valve 18 fully opened when the mini-flow execution condition is not satisfied, and half-opens the discharge valve 18 when the mini-flow execution condition is satisfied. operate as a state. The half-open state means that the opening area of the discharge valve 18 is narrowed, for example, within a range of 50% to 70%.

As shown in FIG. 6, the control unit 58 continues driving the prime mover 51 in step S10, and keeps the clutch 56 connected in step S11. After that, in step S11, it is determined whether or not the conditions for executing the mini-flow are satisfied. Then, if the mini-flow execution condition is satisfied, the opening degree of the discharge valve 18 is set to a half-open state in step S13. Here, the half-open state means switching to the half-open state when the discharge valve 18 is in the fully-open state, and maintaining the half-open state when the discharge valve 18 is in the half-open state. On the other hand, if the conditions for executing the mini-flow are not satisfied, the discharge valve 18 is fully opened in step S14. Here, the fully open state means switching to the fully open state when the discharge valve 18 is in the half-open state, and maintaining the fully open state when the discharge valve 18 is in the fully open state.

Subsequently, in step S15, the control unit 58 determines whether or not a condition for stopping the horizontal shaft pump 10 is satisfied. If the stop condition is not met, the flow returns to step S12 to continue draining the water suction tank 1 and switching the opening degree of the discharge valve 18 . On the other hand, if the stop condition is met, the process ends the wastewater treatment and returns. As a result, the control unit 58 shifts to stop processing.

During this drainage, part of the water that has flowed into the pump casing 12 is discharged by the auxiliary device 25 into the discharge water tank. Further, as the water surface in the suction tank 1 decreases, air is included in the water flow from the water surface toward the suction port 13a (air suction vortex). This air intake vortex is directed to the connecting portion 14b which is the inlet of the auxiliary pipe 27, and at least the air is discharged through the auxiliary pipe 27. As shown in FIG.

FIG. 4 shows the head (H)-flow rate (Q) curve of the horizontal shaft pump 10 of this embodiment. In FIG. 4 , the vertical axis represents the head (H), and the horizontal axis represents the flow rate (Q) and the number of rotations (N) of the main shaft 20 . When the mini-flow of step S13 is executed, the opening of the discharge valve 18 is throttled, and the upstream side outer peripheral portion of the impeller 22, particularly the upper inner peripheral surface of the pump casing 12, flows backward toward the upstream side (backflow in FIG. 2). F) occurs, so there occurs an inflection point at which the operating efficiency fluctuates abruptly as indicated by the dashed line in FIG. However, in this embodiment, the backflow F as described above flows around the auxiliary pipe 27 and is sucked. As a result, as indicated by the solid line in FIG. 4, the inflection point of the operating efficiency can be relaxed as indicated by the solid line.

In the stop processing, the control unit 58 switches the opening/closing states of the discharge valves 18 and 31 and stops driving the prime mover 51 .

Specifically, as shown in FIG. 7, the control unit 58 stops driving the prime mover 51 in step S20. Subsequently, in step S21, the discharge valve 31 of the auxiliary device 25 is switched to the fully closed state, and in step S22, the discharge valve 18 of the horizontal shaft pump 10 itself is switched to the fully closed state. As a result, the stop processing ends, and the control unit 58 shifts to start processing.

Next, the features of the horizontal shaft pump 10 of this embodiment will be described.

At startup, by driving the auxiliary pump 33 , the air inside the pump casing 12 is discharged through the auxiliary pipe 27 and water flows into the pump casing 12 . Water gradually enters the auxiliary pipe 27 together with air, but the air and water are separated by the steam separator 42, and only the air is discharged through the auxiliary pipe 27. - 特許庁Therefore, the inside of the pump casing 12 can be efficiently filled with water, and the water discharge operation can be started.

Since the driving of the auxiliary pump 33 is continued even after the full water sensor 60 detects the full water level (drainage treatment), when an air suction vortex occurs, the air that has flowed into the pump casing 12 is sucked by the auxiliary pump 33 and flows into the auxiliary pipe 27. expelled through Therefore, it is possible to effectively prevent air from colliding with the impeller 22 at the time of draining water, so that the operating characteristics of the horizontal shaft pump can be improved. Moreover, since the water can be drained to a water level at which an air suction vortex is generated, the water in the suction tank 1 can be drained to a low water level.

The steam separator 42 is a cyclone separator that separates air and water by swirling. Therefore, air and water can be separated without using an extra power source (pump) or the like, and only the air can be reliably discharged downstream through the auxiliary pipe 27 . The steam separator 42 has a cylindrical inflow part in which the opening area of the suction port 44a is larger than the opening area of the discharge port 44b. Therefore, since the discharge pressure of the water flowing into the container 46 can be increased, a swirling force can be effectively applied, and air and water can be reliably separated.

The rotation speed of the rotary shaft 38 by the transmission 52 is faster than the rotation speed of the main shaft 20 . Therefore, since the rotary shaft 38 of the auxiliary pump 33 is rotated at a higher speed than the main shaft 20, the air can be reliably discharged through the auxiliary pipe 27, and the size of the auxiliary pump 33 can be reduced.

Auxiliary pump 33 is a self-priming pump having impeller 40 . Therefore, the air in the pump casing 12 can be reliably discharged through the auxiliary pipe 27 at the time of starting, and the air and water in the pump casing 12 can be discharged through the auxiliary pipe 27 at the time of draining after the water is full.

(Second embodiment)
8 and 9 show drainage treatment by the controller 58 of the horizontal shaft pump 10 of the second embodiment. The horizontal shaft pump 10 of this second embodiment has the same basic structure as the horizontal shaft pump 10 of the first embodiment shown in FIGS. That is, the horizontal shaft pump 10 includes a clutch 56 that switches the connection state between the prime mover 51 and the rotary shaft 38 of the auxiliary pump 33 , and the control unit 58 drives the auxiliary pump 33 according to the internal and external conditions of the pump casing 12 . and stop can be switched.

The control unit 58 switches the clutch 56 from the connected state to the disconnected state, for example, when adjusting the outflow rate to a predetermined first flow rate or less by the discharge valve 18 . The defined first flow rate is a discharge amount (for example, 40%) smaller than the discharge amount for the mini-flow (for example, the minimum discharge amount of 50% to 70%). This control is executed, for example, in an emergency when the water level on the downstream side of the pump casing 12 suddenly rises. By throttling the discharge valve 18 and disengaging the clutch 56 without changing the output of the prime mover 51, the discharge pressure of the horizontal shaft pump 10 can be increased. Therefore, even if the pressure of the discharge water tank is high, the water in the water suction tank 1 can be reliably discharged to the downstream side.

Specifically, similarly to the first embodiment, the control unit 58 executes start-up processing when a predetermined start-up condition is satisfied, and executes drainage processing when the pump casing 12 is filled with water. When the stop condition specified in is established, the stop processing is executed. Among them, the start processing and the stop processing are the same as in the first embodiment.

The drainage process of the second embodiment by the control unit 58 differs from that of the first embodiment in that, when an emergency signal is input, the emergency process of excessively throttling the discharge valve 18 is executed. The determination of execution of this emergency process is made after the opening degree of the discharge valve 18 is changed (step S13 or S14) after determining whether or not the mini-flow needs to be executed. Specifically, it is as follows.

As shown in FIG. 8, in the drainage process, the control unit 58 executes steps S10 to S14 in the same manner as in the first embodiment. After changing the degree of opening of the discharge valve 18 (step S13 or S14) depending on whether or not the mini-flow execution condition is satisfied, the controller 58 receives an input signal from the pressure sensor 62 of the discharge water tank in step S15'. Based on the above, it is determined whether or not to execute emergency processing. That is, when the controller 58 determines from the input signal from the pressure sensor 62 that the pressure in the discharge tank is higher than the predetermined pressure, it executes the emergency process of step S16'. On the other hand, if it is determined that the discharge water tank is not at a high pressure, it is determined at step S17' whether or not the stop condition is satisfied without executing the emergency process at step S16'.

Referring to FIG. 9, in the emergency process, the control unit 58 sets the discharge valve 18 to a slightly open state (opening area of 40%) in step S16'-1, and sets the discharge valve 31 to a fully closed state in step S16'-2. do. Thereafter, after switching the clutch 56 from the engaged state to the disengaged state in step S16'-3, the system waits until the emergency signal is cut off (that is, until the pressure in the discharge water tank becomes low) in step S16'-4. When the emergency signal is interrupted, the controller 58 switches the discharge valve 31 to the fully open state in step S16'-5, and then switches the clutch 56 from the disconnected state to the connected state in step S16'-6 to return. do.

With the horizontal shaft pump 10 of the second embodiment, it is possible to obtain the same actions and effects as the horizontal shaft pump 10 of the first embodiment. Moreover, in the horizontal shaft pump 10 of the second embodiment, when an emergency signal is received during drainage, the discharge valve 18 is throttled more than during the mini-flow without changing the output of the prime mover 51, the clutch 56 is disengaged, and the auxiliary pump is discharged. Since the driving of 33 is stopped, the discharge pressure can be increased. Therefore, even if the water level in the discharge water tank is high and the pressure is high, the water in the water suction tank 1 can be reliably discharged to the downstream side, so that the overflow of the water suction tank 1 side can be prevented.

Note that the horizontal shaft pump 10 of the present invention is not limited to the configuration of the above-described embodiment, and various modifications are possible.

For example, the auxiliary pump 33 is not limited to the self-priming pump having the impeller 40, and may be a vacuum pump. The steam separator 42 is not limited to a cyclone separator, and may be modified as necessary as long as it is configured to separate incoming air and water. The impeller 22 of the transverse pump 10 itself and the impeller 40 of the auxiliary pump 33 may each be rotated (driven) by separate prime movers. The horizontal shaft pump 10 of the first embodiment may not have the clutch 56 .

DESCRIPTION OF SYMBOLS 1... Suction tank 10... Horizontal shaft pump 12... Pump casing 13... Suction bell 13a... Suction port 14... Bent elbow 14a... Through part 14b... Connection part 15... Vane casing 15a... Guide vane 15b... Bearing casing 16... Underwater bearing 17 Water pipe 18 Discharge valve 20 Main shaft 20a First end 20b Second end 22 Impeller 25 Auxiliary device 27 Auxiliary pipe 28 First pipe 28a Ascending portion 28b Curved portion 28c Descending portion 28d Connection portion 28e Swelling portion 29 Second pipe 29a Vertical pipe portion 29b Horizontal pipe portion 30 Water pipe 31 Discharge valve 33 Auxiliary pump 35 Casing 35a Suction portion 35b Discharge portion 35c Passage portion 35d Current plate 35e Partition wall 35f Bearing 35g Recess 36 Check valve 38 Rotary shaft 38a First end 38b Second end 40 Impeller 42 Steam separator 43 Partition 44 Inflow 44a... Suction port 44b... Discharge port 45... Recirculation hole 46... Container 46a... Upstream end 46b... Downstream end 47... Supplementary air space 50... Drive device 51... Motor 51a... Output shaft 52... Transmission 53... Drive Gear 54 First driven gear 55 Second driven gear 56 Clutch 58 Control unit 60 Full water sensor 62 Pressure sensor

Claims (7)

a pump casing having a suction port disposed in a suction sump and extending horizontally above the suction port;
a main shaft having a first end located within the pump casing and a second end located outside the pump casing, the main shaft being rotatably disposed in the pump casing so as to extend in a horizontal direction;
an impeller arranged on the first end side of the main shaft;
an auxiliary pipe connected to an upper portion of the pump casing upstream of the impeller;
an auxiliary pump interposed in the auxiliary pipe for sucking air in the pump casing;
a steam separator provided upstream of the auxiliary pump in the auxiliary pipe and separating air and water flowing into the auxiliary pipe;
a full water sensor for detecting that the pump casing is filled with water;
and a control unit that drives the impeller and the auxiliary pump, and continues driving the impeller and the auxiliary pump even after the full-water sensor detects full water. 2. The horizontal shaft pump according to claim 1, wherein the steam separator is a cyclone separator that separates air and water by swirling. The cyclone separator has a suction port that opens inside the pump casing and a discharge port that opens on the side of the auxiliary pipe. The opening area of the suction port is larger than the opening area of the discharge port. 3. The horizontal shaft pump of claim 2, comprising a section. a transmission for transmitting the power of the prime mover to the main shaft and the rotating shaft of the auxiliary pump;
4. The horizontal shaft pump according to any one of claims 1 to 3, wherein the speed of rotation of said rotary shaft by said transmission is faster than the speed of rotation of said main shaft by said transmission. 5. The apparatus according to claim 4, further comprising a clutch interposed on the rotating shaft for switching between a connected state in which the power of the prime mover can be transmitted to the auxiliary pump and a disconnected state in which the power of the prime mover cannot be transmitted to the auxiliary pump. Horizontal shaft pump as described. A valve connected to the pump casing and capable of adjusting an outflow rate from the pump casing to the downstream side,
6. The horizontal shaft pump according to claim 5, wherein the control unit switches the clutch from the connected state to the disconnected state when the valve adjusts the outflow rate to a predetermined first flow rate or less. 7. Horizontal axis pump according to any one of claims 1 to 6, wherein the auxiliary pump is a self-priming pump with a rotatable impeller.

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