JP2013079648A - Pump facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump facility to which a siphon pipe forming a siphon is connected on a pump discharge side, improving controllability (operability), maintainability, economical efficiency, and reliability.SOLUTION: The pump facility to which the siphon pipe 20 forming the siphon is connected on the pump discharge side, includes a water receiving frame 50 arranged at a position where the frame covers a lower part of surroundings and an end face of an opening end of the siphon pipe 20, the water receiving frame having a capacity smaller than that of a discharge water tank 24 and causing discharged water to flow over from above the end face of the opening end.

Description

  The present invention relates to a pump facility that operates by forming a siphon in a siphon pipe connected to the discharge side of the pump.

  Pump equipment that operates by forming a siphon in the siphon pipe connected to the discharge side of the pump as a simplified pump equipment without the need to install valves such as a discharge valve in the pump main pipe ( Siphon type pump equipment) is known.

  FIG. 1 shows a conventional general pump installation of this kind. As shown in FIG. 1, the pump facility includes a pump 18 that pumps up water 16 in the suction water tank 14 by the rotation of the impeller 12 that is driven by the driving machine 10. One end of a siphon pipe 20 is connected to the discharge port of the pump 18, and the open end 22 of the siphon pipe 20 is located inside the discharge water tank 24 and is immersed in the water 26 stored in the discharge water tank 24. It is supposed to be.

  The siphon pipe 20 has a rising pipe 28 that rises vertically, a top pipe 30 that extends horizontally at the top, and a drooping pipe 32 that droops vertically, and the inside of the siphon pipe 20 at the top of the top pipe 30 when stopped. A siphon breaker (valve) 34 is provided to prevent back flow to the suction water tank 14 side by introducing air into the siphon.

  In this example, in order to simplify the equipment, the siphon is formed by the self-siphoning operation of the pump 18 (operation in which the actual lift is approximately the top of the siphon piping). A method of driving the pipe 20 with water is also performed. In addition, a divergent pipe 36 that gradually expands downward is connected to the bottom of the drooping pipe 32, thereby reducing discharge loss and reducing the head loss, but instead of the divergent pipe, a straight pipe is used. May be used.

  In this pump facility, when the suction water tank 14 reaches a predetermined water level, the impeller 12 of the pump 18 is rotated by driving the driving machine 10, and the water 16 in the suction water tank 14 is siphoned. Through 20, water is pumped into the discharge water tank 24. When the siphon is formed in the siphon pipe 20, the actual head of the siphon forming portion is eliminated, and the actual head Ha at that time is the difference between the discharge water level and the suction water level. In addition, when the siphon is not formed in the siphon pipe 20 (during the formation process), the water pushed up by the pump 18 overflows to the upper part of the siphon pipe 20, and the actual lifting height Hb at that time is over the top of the siphon pipe 20. It is the difference between the water surface and the suction water level.

  In addition, as shown in FIG. 2, one end of the bent pipe 38 is connected to the hanging pipe 32 to form the siphon pipe 20, and the other end of the bent pipe 38 is connected to the side wall of the discharge water tank 24. Yes. In this case, in order to form a siphon during pump operation, the upper end level (▽ PL) of the opening end 22 of the siphon pipe 20 is set at a position lower than the lowest water level (▽ LWL) during operation of the discharge water tank 24. Must be submerged.

  In a conventional pump facility that operates by forming a siphon, since the main pipe is not provided with a valve, the pump discharge flow rate cannot be controlled by the valve. In addition, although the discharge flow rate of a pump can be controlled by using rotational speed control and blade angle control, if such a control means is provided, it will become expensive and inferior in economy.

  In addition, it is necessary to submerge the open end of the siphon piping in the discharge water tank, which increases the piping length, increases the piping loss, increases the cost of piping, and increases the piping loss. Equipment costs such as up are expensive. In addition, if the water level in the discharge tank is low and the discharge pipe does not submerge in the discharge water tank due to management operation, etc., the actual head is high with the overflow level at the top of the siphon pipe (the top of the siphon pipe is It may be an operation at the actual head) and satisfactory management operation may not be performed. That is, the operation is performed with a small amount of water having a high actual head, and problems such as (1) increase in vibration and (2) increase in required power and consumption of fuel or electric power in the axial flow pump characteristics occur. In addition, when the vibration is large, the continuous operation time is also limited (the management operation cannot be performed by proper continuous operation).

  Furthermore, the time required to form a siphon due to the self-siphon system in which the siphon is formed by the discharge flow of the main pump or the filling of the siphon piping by the vacuum pump is as long as about 5 to 10 minutes, and the wastewater is accompanied by a rapid inflow. At the machine, there is a risk of inundation damage due to inadequate drainage due to the small amount of water operation time (start-up time) when the siphon is not formed (during the formation process). Furthermore, most of the pump failures occur at the time of starting, which is not preferable from the viewpoint of reliability. In addition, as described above, since the pump discharge flow rate cannot be controlled, it is necessary to stop and operate the pump as the suction water level decreases and rises, and it is necessary to start and stop frequently. The reliability is further reduced.

  In addition, in the case of pump equipment that performs self-siphoning, operation with a high actual head is temporarily required at the time of start-up, so an axial flow pump having a stall area with a high actual head (small water volume) is required. It may not be usable. Even if it can be used, due to the characteristics of the axial flow pump, the required shaft power is higher at the operating point with a higher head. It is necessary to give the drive machine the above output, that is, the output exceeding the power required for the pump operation at the planned actual head.

  In order to solve the problems of the above siphon type pump equipment, the siphon breaker is controlled to be fully open / closed to control two operating points: siphon operation and low water operation with the pipe head level as the actual head. And what was comprised so that low water volume driving | operation could be performed (refer patent document 1, 2) is proposed. However, in this case, continuous flow rate control cannot be performed, and it is difficult to cope with strict control such as constant water level control of the suction water tank, so that practical operation cannot be performed. Further, in the operation with the pipe head as the actual head, a high specific speed pump such as an axial flow pump becomes an unstable operation region, and there is a problem that vibration or the like becomes larger than that in the normal operation. In addition, the high specific speed pump has a characteristic that the required shaft power is increased, resulting in uneconomic operation.

  In addition, there has also been proposed a configuration in which siphon formation is assisted by expanding and contracting the opening end of the siphon piping in accordance with the water level of the discharge water tank (see Patent Document 3). However, in this case, a complicated mechanism is required at the opening end of the siphon piping, and the simplification effect due to the omission of the valve is not obtained. Moreover, the inside of the discharge water tank is generally a portion that is difficult to perform maintenance, and is difficult to maintain.

  In addition, the pumps are connected in series, and only when starting siphon formation, they are operated in series to meet the required high actual head (actual head up to the top of the pipe) and adopt a low head pump (high specific speed pump). A configuration that can be used (see Patent Document 4) has also been proposed. In this case, since the pumps are connected in series, the starting pump portion (the pump that is not in operation) is configured as a suction or siphon piping line during normal operation. However, the inside of the pump generally has a complicated structure, so a large head loss occurs, and the total head required for regular drainage (when forming a siphon) is larger than conventional pumps, resulting in uneconomical pump equipment. . In addition, in a pump that is connected in series and does not operate, the pump rotates even if it is not operated, so that the same maintenance management as that of the pump that performs the operation is necessary, and the maintenance management is also deteriorated.

JP-A-8-296579 JP 2004-339970 A JP 2004-270474 A JP 2006-233865 A

  The present invention has been made in view of the above, and in a pump facility in which a siphon pipe forming a siphon is connected to a pump discharge side, a pump having improved controllability (operability), maintainability, economy, and reliability. The purpose is to provide equipment.

  In the pump facility in which the siphon pipe forming the siphon is connected to the pump discharge side, the capacity of the invention according to claim 1 is smaller than the discharge water tank at a position covering the periphery of the opening end of the siphon pipe and the lower end surface, And it is the pump installation characterized by arrange | positioning the water receiving frame which overflows discharge water from the upper direction from the said opening end surface.

  Thus, regardless of the water level of the discharge water tank, even if the water level of the discharge water tank is below the opening end of the siphon pipe, it is possible to form a siphon in the siphon pipe, which makes it easy even when the external water level is low. In addition, it becomes possible to perform the management operation in the siphon state, and the maintenance management is improved. In addition, by converting the downward flow into the upward overflow flow, scouring of the lower portion of the discharge water tank can be prevented.

You may provide the water level meter which calculates the discharge flow volume of a pump by measuring the water level of the discharge water which overflows from the said water receiving frame.
As a result, it is possible to accurately measure the pump discharge rate because the overflow rate by the weir can be measured. (Water amount measurement by the weir is widely used as a method for measuring the amount of water discharged during pump factory tests. Is also a precise method specified).

According to a second aspect of the present invention, in the pump facility according to the first aspect, a curved flow path forming surface or an inclined surface for changing the flow direction of the discharged water is provided on the bottom surface of the water receiving frame. is there.
Thereby, the flow of water is prevented from being disturbed in the water receiving frame, an excessive force is not applied to the water receiving frame, and adverse effects such as vibration can be prevented. In addition, by changing the direction of the flow so that the discharged bubbles do not stagnate vertically below the siphon piping, the discharged bubbles are released almost entirely from the discharge water tank to the atmosphere without returning to the pipe by buoyancy, Siphon formation time can be shortened compared to conventional methods, and operability and reliability (early rated drainage can be secured) can be improved.

The invention according to claim 3 is the pump equipment according to claim 1, wherein the water receiving frame is arranged such that an overflow end of the water receiving frame is higher than a discharge-side maximum water level.
As a result, only the water in the receiving frame flows backward when the pump is stopped, and when the water in the receiving frame finishes flowing back, the air naturally enters from the open end of the siphon piping, and the inside of the siphon piping is steady (normal pump (Shutdown state) can be brought into a dry state, so that a siphon breaker such as a valve is not necessary, and the risk of backflow and water immersion due to failure of the siphon break valve or the like can be avoided, thereby improving the reliability.

  ADVANTAGE OF THE INVENTION According to this invention, in the pump installation which connected the siphon piping which forms a siphon to the pump discharge side, the pump installation which improved controllability (operability), maintainability, economical efficiency, and reliability can be provided.

It is a schematic diagram which shows the conventional pump equipment. It is a schematic diagram which shows the principal part of the other conventional pump equipment. It is a schematic diagram of other pump equipment. It is a flowchart which shows the flow control basic logic of the pump installation shown in FIG. It is a flowchart which shows the further other flow control basic logic of the pump installation shown in FIG. It is a graph attached | subjected to description of the flow control in a prior art example. It is a graph attached | subjected to description of the flow control in the flow control basic logic shown in FIG. It is a schematic diagram of other pump equipment. It is a D direction arrow directional view of FIG. FIG. 9 is a view corresponding to FIG. 9 showing a modification of the pump facility shown in FIG. 8. It is a schematic diagram of pump equipment of an embodiment of the invention. It is a perspective view of the water receiving frame of the pump equipment shown in FIG. It is a perspective view which shows the example from which each water receiving frame differs. It is sectional drawing which shows the further different example of a water receiving frame with the opening part of siphon piping. It is a figure which shows the relationship between the water receiving frame and bubble which are shown in FIG. It is sectional drawing which shows the further different example of a water receiving frame with the opening part of siphon piping. It is a schematic diagram of the pump installation of other embodiment of this invention. It is a schematic diagram which shows the other usage example of the pump installation shown in FIG. It is a schematic diagram which shows the further another usage example of the pump installation shown in FIG. It is a perspective view which shows the water receiving frame of the pump installation shown in FIG. It is a schematic diagram of other pump equipment. It is a principal part schematic diagram of the conventional pump equipment. Furthermore, it is a principal part schematic diagram of another pump installation. It is a principal part schematic diagram of the other conventional pump equipment. It is another principal part schematic diagram of a pump installation. It is a schematic diagram of other pump equipment. It is a schematic diagram of other pump equipment. It is a figure which shows the state which the water level in siphon piping rises immediately after starting. It is a schematic diagram of other pump equipment. It is a graph which shows the relationship between the shaft power in the starting method of pump equipment, and pump discharge amount. It is a graph which shows the relationship between the total head and the pump discharge amount in the other starting method of pump equipment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following examples, members that are the same as or correspond to those in the conventional example shown in FIGS. 1 and 2 are assigned the same reference numerals, and redundant description is omitted.

FIG. 3 shows still another pump facility. The example shown in FIG. 3 is different from the example shown in FIG. 1 in that the top pipe 30 of the siphon pipe 20 is composed of an opening / closing valve, and air is caused to flow into the siphon pipe 20 by the opening / closing operation. Is provided with a flow control valve 40 for continuously or intermittently controlling the pressure and volume of the air reservoir formed to control the discharge amount of the pump 18, and further, near the inlet of the siphon pipe 20. The pressure gauge 42 for measuring 18 discharge pressures is provided.
In addition, in the example shown in FIG. 3, although the flow control valve is comprised by 1 unit | set, it is good also considering a controllability and it is good also considering a plurality of flow rate control valves.

FIG. 4 shows the basic flow control logic of the pump equipment shown in FIG. As shown in FIG. 4, the pump 18 is started to start the siphon forming operation, and the pressure gauge 42 measures the pump discharge pressure to detect whether or not the siphon is formed in the siphon pipe 20. And after detecting that the siphon was formed in the siphon piping 20, the flow control mode is turned ON. In the state where the flow rate control mode is ON, the current value and the target value at the flow rate or the discharge pressure are compared, and the flow rate control valve 40 is opened by the flow rate “decrease” command, and is formed in the top portion of the siphon pipe 20. The pressure and volume of the air reservoir are controlled, and the flow rate is increased by a flow rate “increase” command.
In addition, when increasing to the rated water volume of the pump, the operation is performed with the rated water volume by shifting from the pressure siphon to the complete siphon by the closing operation of the flow control valve 40.

  Here, the complete siphon is in a state in which the discharge pressure of the pump 18 is low in a state where the air in the siphon pipe 20 has been released, and is stable at the entire head during siphon formation (actual head lift during siphon + pipe loss). In other words, in the pressure siphon, the air in the siphon pipe 20 is not completely removed, but the discharge pressure of the pump 18 is almost the same as that of the complete siphon, that is, the residual air has a slight pipe loss at the time of the complete siphon. It means that it is getting bigger.

  In conventional siphon equipment that does not have a discharge valve, the pump flow rate cannot be controlled, and even when the pump flow rate is controlled, it is completely the same as the atmospheric discharge operation (high actual head operation) at the top of the pipe before the siphon is formed. Fine control such as performing constant control of the water level of the suction water tank 14 could not be performed only by two-stage control by two operation points of siphon operation.

  According to this example, by controlling the pressure and volume of the air reservoir formed in the top of the siphon pipe 20 in the (pressure) siphon state by the flow control valve 40, it is similar to the throttle control by the discharge valve. An effect can be obtained, and continuous flow rate control equivalent to valve control becomes possible.

  The flow rate “decrease” command and the flow rate “increase” command are constituted by, for example, a command issued from a suction water tank water level constant control function which is separately configured. The flow rate “decrease” command and the flow rate “increase” command may be configured by a command issued from a separately configured discharge tank water level control function (water volume command by limiting the amount of drainage due to high water level, etc.), and flow rate setting by an operator You may comprise by.

  In this example, the flow rate is controlled by flowing air into the siphon pipe 20, but the siphon pipe 20 is in an almost atmospheric pressure state when the siphon is not formed, and an air reservoir in the siphon pipe 20. It is difficult to control the pressure and volume with the flow control valve 40. For this reason, as shown in FIG. 4, a siphon (complete siphon or pressure siphon) is formed once, or the air entrained operation state in which the residual air is entrained and discharged from the top of the siphon pipe 20 is discharged. It is preferable to control the flow rate after detecting the formation.

  FIG. 5 shows still another flow control basic logic of the pump equipment shown in FIG. In this example, the target pump discharge pressure corresponding to the current suction water level is calculated from the setting table based on the pump characteristics incorporated in the pump control equipment or the pump parallel operation characteristics for any flow rate setting value. By comparing the pressure with the current discharge pressure, the flow control valve 40 is controlled to be opened and closed.

  That is, in the state where the flow rate control mode is ON, the pump pressure value corresponding to the target flow rate is calculated from the flow rate value manually input or separately output from the control mechanism, the water level of the suction water tank 14, and the pump flow rate characteristic curve data. Then, the calculated pressure (calculated pressure) is compared with the current discharge pressure (current discharge pressure), and when the current discharge pressure <calculated pressure, a flow rate “decrease” command is issued and the flow rate control valve 40 is set to “ Open ”. On the other hand, when the current discharge pressure> the calculated pressure, the flow rate “increase” command is issued, the flow rate control valve 40 is set to “closed”, and the self-siphon function (air discharge operation) is used to perform the transition operation from the self-siphon to the complete siphon. Do. When the current discharge pressure is not equal to the calculated pressure, the above operation is repeated, and when the current discharge pressure is equal to the calculated pressure (current discharge pressure = calculated pressure), the flow control valve 40 is stopped.

  In this way, operability (flow rate control based on the judgment of the machine operator) can be improved by controlling the pump 18 not by feedback control of the water level but by flow rate setting. Moreover, even in a pump facility in which a plurality of pumps (bore diameter / model / drive machine, etc.) having different characteristics are installed, for example, operation pattern setting / command is based on the control facility incorporating the pump characteristics. It is possible to operate with an efficient operation pattern and operate the drainage station with high efficiency by separately issuing the setting signal of each pump flow rate that is most efficient than the operation control function. The operation control function may be incorporated in the pump control facility.

That is, in the conventional example, as shown in FIG. 6, the intersection A between the pipe loss and the pump QH characteristic in the actual lift when the siphon is not formed, and the pipe loss and the pump Q− in the actual lift when the siphon is formed. Only two-stage flow control of the intersection B of the H characteristic was possible. According to this example, it is possible to change the absolute pressure and volume of the air reservoir formed in the siphon pipe 20 by adjusting the air amount, thereby changing the actual pump head as shown in FIG. Then, the pump flow rate is changed from the intersection A between the pipe loss and the pump QH characteristic in the actual head when the siphon is not formed to the intersection B (approximately A to B between the pipe loss and the pump QH characteristic in the actual head when the siphon is formed. Point) can be controlled steplessly. In this case, since the volume of the air reservoir also changes, the pipe loss also changes slightly.
Moreover, in order to prevent the allowable output of the drive machine and the operation in the stall area of the pump, it may be controlled to limit (lower limit) the minimum discharge water amount of the pump to be controlled.

  8 and 9 show still another pump facility. 3 is different from the example shown in FIG. 3 in that a rectangular pipe is used as the siphon pipe 20, and a plurality (three in the figure) of partition plates 44 are arranged in the vertical direction inside the siphon pipe (rectangular pipe) 20. Then, the inside of the siphon pipe 20 is divided into a plurality of vertical flow paths 20a to 20d, and the divided flow paths 20a to 20d are divided into air pockets formed in the tops of the flow paths 20a to 20d. The flow rate control valves 40a to 40d for continuously controlling the discharge amount of the pump 18 by controlling the pressure and the volume are provided respectively.

  According to this example, the interior of the siphon pipe 20 is divided into a plurality of flow paths 20a to 20d, thereby controlling the amount of air accumulated in the siphon pipe 20 with high accuracy and adjusting and controlling the flow rate of the pump 18 with high accuracy. be able to.

  As shown in FIG. 10, a plurality (three in the figure) of partition plates 46 are arranged in the vertical direction only inside the top pipe 30 of the siphon pipe 20, and only the inside of the top pipe 30 is arranged in a plurality of vertical directions. You may make it divide | segment into these flow paths 30a-30d. Thereby, discharge piping can be comprised at low cost. Further, the flow control valve 40 may have a siphon break function, and the siphon breaker 34 may be omitted.

  11 and 12 show a pump facility according to the embodiment of the present invention. In this example, the lower end of the drooping pipe 32 is the opening end 22 of the siphon pipe 20, and the capacity is smaller than the discharge water tank 24 and the discharge water is opened to the opening end 22 at a position covering the periphery of the opening end 22 and below the end face. A water receiving frame 50 that overflows from above the end face of the water is disposed, and further, a water level that measures the water level of the discharged water that overflows from the water receiving frame 50 and calculates the discharge flow rate of the pump 18 above the water receiving frame 50. A total of 52 is arranged.

  In this example, as the water receiving frame 50, a rectangular shape opened upward as shown in FIG. 12 is used, but as shown in FIG. 13 (a), a circular shape opened upward. Even if it uses, as shown in FIG.13 (b), you may use the thing of the truncated quadrangular pyramid shape opened upwards, and the shape of the water receiving frame 50 is selected arbitrarily it can.

  According to this example, a siphon can be formed in the siphon pipe 20 regardless of the water level of the discharge water tank 24, that is, even when the water level of the discharge water tank 24 is below the opening end 22 of the siphon pipe 20. This makes it possible to easily form a siphon state even in a state where the outside water level is low, such as during a management operation, thereby improving maintenance. Moreover, by converting the downward flow into the upward overflow flow through the water receiving frame 50, scouring of the lower portion of the discharge water tank 24 can be prevented. When draining directly to the dike slope, it is necessary to consider scouring prevention, and this example is effective.

  In this example, the water level of the discharged water overflowing from the water receiving frame 50 is measured by the water level meter 52, the overflow depth h of the overflow water is calculated from the water level, and the pump 18 is calculated from the calculated overflow depth h. The discharge flow rate is calculated.

  From the pump performance curve (flow rate – total head curve), the pump discharge flow rate can be estimated from the discharge pressure, suction water level, etc., but the pump performance is not the same as the actual site installation situation at the factory test site. For this reason, it is known that the performance in the factory test is slightly different from the actual performance in the field. Therefore, in the ejection amount estimation from the performance curve, the accuracy of the estimated value is worse than the accuracy by a normal measuring instrument.

According to this example, it is possible to measure the overflow rate by the weir, so it is possible to accurately grasp the pump discharge amount (water amount measurement by the weir is widely used as a method for measuring the amount of water discharged during pump factory testing. This is a highly accurate method specified in JIS). For example, the pump discharge amount Q can be calculated from the following formula of the overflow water amount of the square weir.
Q = C × B × h (1)
Here, C: flow coefficient (coefficient determined by various structures such as receiving water frame), B: overflow width, h: overflow water depth

  As shown in FIGS. 14 and 15, a curved flow path forming surface 54 a that changes the flow direction of the discharged water may be provided on the bottom surface of the water receiving frame 50. Thereby, the flow of water in the water receiving frame 50 is not disturbed, an excessive force is not applied to the water receiving frame 50, and adverse effects such as vibration can be prevented. In addition, as shown in FIG. 16, you may make it provide the inclined surface 54b which changes the flow direction of discharged water in the bottom face of the water receiving frame 50. As shown in FIG. Such an inclined surface 54b can be easily formed by a plate material.

  In the self-siphon, the air in the siphon piping is entrained by the discharge water flow of the main pump, and the siphon is formed by taking it out of the tube, but the entrained bubbles have upward levitation force due to the influence of buoyancy. doing. For this reason, in the conventional example, when the water flow discharged from the open end of the siphon pipe flows vertically downward, the bubbles try to return to the siphon pipe again due to buoyancy, until the siphon is formed. Takes a lot of time.

  According to this example, the direction of the discharged water flow is changed so that the bubbles entrained by the water flow do not stagnate vertically below the siphon pipe 20, and the discharged bubbles do not return into the siphon pipe 20 due to buoyancy. By making almost all of the water receiving frame 50 open to the atmosphere, the siphon formation time can be shortened compared to the prior art, and the operability and reliability (early rated drainage secured) can be improved.

  The water flow control mechanism such as the curved flow path forming surface 54a and the inclined surface 54b is provided in the discharge water tank 24 on the downstream side of the opening end of the pump discharge pipe not having a water receiving frame to discharge bubbles. You may comprise so that air | atmosphere may be opened | released more efficiently than the inside of the water tank 24. FIG. Further, the opening end may be installed by being shifted from the central portion of the discharge water tank, and the water flow direction may be changed using a haunch at the water tank end.

  FIG. 17 shows a pump facility according to another embodiment of the present invention. The pump equipment is different from the examples shown in FIGS. 11 and 12 in that the siphon breaker and the water level gauge are omitted. And the water receiving frame 50 is arrange | positioned so that the overflow end of this water receiving frame 50 may become a position higher than a discharge side highest water level.

For example, as schematically shown in FIG. 18, this example has a great effect when the discharge water tank is not near the pumping station and is discharged to the discharge river water 58 over the bank waterproof pipe bridge 56. In the case of this example, the actual head can be reduced by the height h ₁ shown in FIG.

  In the conventional siphon equipment, if the siphon is not destroyed when the pump is stopped, the discharge water tank and the discharge river water flow back (infinitely) to the pump suction water tank through the siphon pipe. For this reason, when the pump is stopped, air is introduced into the siphon piping to destroy the siphon (siphon break) to prevent backflow. According to this example, the reverse flow when the pump 18 is stopped is only the amount of water in the water receiving frame 50, and when the water in the water receiving frame 50 finishes flowing back, the opening end 20 of the siphon pipe 20 Air naturally enters and the siphon pipe 20 is in a steady (normal pump stop state) dry state. As a result, a siphon break valve or the like can be omitted, and the risk of backflow or water inundation due to a failure of the siphon break valve or the like can be avoided to improve reliability.

  As shown in FIGS. 19 and 20, when the water receiving frame 50 is installed on the slope, the overflow direction from the water receiving frame 50 is not the entire surface but only one direction for the protection of the slope. good. As shown in FIGS. 18 and 19, the siphon pipe 20 may be applied not only to a vertical pipe but also to an oblique pipe that is inclined along the slope of a bank. Moreover, the material of the siphon piping is not limited to a steel pipe or cast iron pipe, but may be a hose or a resin tube used in an emergency drain pump car or the like.

  In recent years, there has been a situation in which rainwater suddenly flows into a pumping station that drains water due to localized torrential rain, and rapid pump start-up (drainage with a planned amount of water) is strongly demanded. In the siphon type pump equipment, until the siphon is formed, the operation state is higher than the planned practical use, and the discharge amount of the pump becomes the operation less than the planned discharge water amount. For this reason, how quickly the siphon is formed and the rated discharge water amount is drained (starting quickly) leads to prevention of inundation damage due to drainage delay, and the reliability can be greatly improved.

  FIG. 21 shows still another pump facility. In this example, the curved pipe 60 is connected to the lower end of the drooping pipe 32, and the siphon is discharged from the opening end of the siphon pipe 20, that is, the opening end of the curved pipe 60, approximately horizontally into the discharge water tank 24. An inclined portion 62 that constitutes the pipe 20 and further inclines upward toward the downstream side is formed on the upper surface of the curved pipe 60 that extends horizontally.

  In FIG. 21, the inclined portion 62 is configured by a plate having a flat surface, but the inclined portion 62 may be configured by a member having a curved surface. The curved pipe 60 may be a substantially circular pipe or a rectangular pipe. In particular, when a rectangular tube is used, the upper end level of the opening can be set low while maintaining the designed opening area as a rectangular shape, and the opening end becomes submerged even when the water level on the discharge side is low. Thus, siphon can be easily formed.

  In the siphon piping, air entrained in the discharge water flow of the main pump at the top of the siphon piping becomes bubbles and is taken to the discharge water tank. As shown in FIG. 22, a bent tube 60 is connected to the lower end of the drooping pipe 32. Thus, in the conventional example in which the siphon pipe 20 is configured so that the discharge water is discharged into the discharge water tank substantially horizontally, the bubbles are stagnated on the upper surface of the curved pipe 60 in the vicinity of the opening end 22 and completely. It takes time to form a siphon. This is a phenomenon that occurs due to the stagnation in the flow at the top of the open end 22 and the entrained water flow speed is not sufficient with respect to the rising speed of the bubbles.

  According to this example, by forming the inclined portion 62 that is inclined upward toward the downstream side on the upper surface of the curved pipe 60, the bubbles that have passed through the starting end of the inclined portion 62 are self-regarded regardless of the water flow. It flows into the discharge water tank 24 and is released to the atmosphere due to its floating ability. That is, since the bubbles do not stagnate, all the air is discharged from the siphon pipe 20 in a short time, and the starting time can be shortened.

  FIG. 23 shows the main part of still another pump facility. In this example, a swirl flow generating plate 64 is provided in a divergent pipe 36 that is connected to the lower end of the drooping pipe 32 of the siphon pipe 20 and arranged in the vertical direction, and directed downward in the vertical direction that flows along the divergent pipe 36. A centrifugal flow speed component is given to the flowing discharge water flow by the swirl flow generating plate 64. In this example, a swirl flow generating plate 64 made of a plate material is obliquely installed on the inner peripheral surface of the divergent pipe 36 to generate a swirl flow. However, as the swirl flow generating plate 64, a three-dimensional plate is used. Then, a swirling flow may be generated.

  In the conventional siphon pipe 20 in which the divergent pipe 36 is vertically connected to the lower end of the hanging pipe 32, as shown in FIG. 24, the bubbles once discharged from the open end 22 of the siphon pipe 20 rise again. A phenomenon remains in the siphon pipe 20.

  According to this example, by giving a centrifugal direction component to the water flow flowing vertically downward, the bubbles discharged from the opening end 22 of the siphon pipe 20 are lifted again and returned to the siphon pipe 20, thereby eliminating the bubbles. The bubbles can be smoothly discharged from the siphon pipe 20 to shorten the siphon formation time.

  In addition, as shown to Fig.25 (a), you may comprise so that the inclination piping 66 may be used as piping connected to the opening end 22 of the siphon piping 20, and a discharge water flow may not turn to the perpendicular downward direction. In this case, by forming the opening end 22 by cutting the inclined pipe 66 in a substantially vertical direction, it is possible to guide the bubbles to the discharge water tank 24 while maintaining the flow velocity of the lower water flow, and to discharge the bubbles more effectively. It becomes possible to do. That is, as shown in FIG. 25B, when the inclined pipe 66 is cut at a right angle to form the opening end 22a, the flow velocity immediately after the opening end 22a (immediately after the discharge) becomes slow, and the upper end of the opening end 22a. Air bubbles tend to stagnate.

  FIG. 26 shows still another pump facility. In this example, the communication pipe 70 communicates the approximate top of the top pipe 30 of the siphon pipe 20 and the secondary side of the curved pipe bent portion installed downstream of the top pipe 30, that is, the back side of the hanging pipe 32. Further, a curved pipe 60 is connected to the lower end of the hanging pipe 32 so that the open end of the bent pipe 60 becomes the open end 22 of the siphon pipe 20.

  The secondary side of the curved pipe, which becomes the overflow section during the siphon formation process, is in a state where the flow is separated, and that part has a negative pressure. In order to shorten the siphon formation time, a major factor is how the air in the siphon pipe 20 is entrained with the pump discharge water flow. According to this example, a drooping pipe 32 serving as a negative pressure part on the secondary side of the curved pipe bending part installed on the downstream side of the substantially top pipe 30 and the substantially top part of the top pipe 30 where the air of the siphon pipe 20 accumulates. By connecting the back side of the pipe with the communication pipe 70, the air at the top of the siphon pipe 20 is naturally taken into the drooping pipe 32 that becomes a negative pressure section due to the pressure difference, and then taken along with the water flow, and the discharge water tank 24 is opened to the atmosphere. As a result, the air in the siphon pipe 20 can be taken more effectively than before, the siphon formation time can be shortened, the start delay can be prevented, and the reliability of the drainage station can be improved.

  Of course, for example, the communication pipe 70 of this example may be combined with each pump facility in each of the above embodiments.

  FIG. 27 shows still another pump facility. This example includes an auxiliary pump 74 that is started when the pump 18 is started and discharges discharged water from the substantially top of the top pipe 30 of the siphon pipe 20 through the auxiliary pipe 72.

  Immediately after the pump 18 is started, the water flow in the siphon pipe 20 becomes a waterfall from the top pipe 30 of the siphon pipe 20 as shown in FIG. It will be in the state of being taken out of the piping 20. Then, when the air in the pipe is discharged to some extent, the water level in the siphon pipe 20 rises as shown in FIG. 28 (b), and the top pipe 30 of the siphon pipe 20 as shown in FIG. 28 (c). When the bottom level (PTL) or more is reached, the water flow (surface flow) becomes stable and the air in the siphon pipe 20 cannot be effectively entrained.

  According to this example, as shown in FIG. 28 (c), when the water level in the siphon pipe 20 is at the top of the siphon pipe 20, the auxiliary pump 74 passes the auxiliary pipe 72 to the top of the siphon pipe 20. The discharge water is discharged, the water surface at the top of the siphon pipe 20 is disturbed, and residual air is entrained in the water flow, so that the air accumulated at the top of the siphon pipe 20 is forcibly taken into the discharge water flow of the pump 18. It is possible to entrain, shorten the siphon formation time, and improve the reliability.

  FIG. 29 shows still another pump facility. In this example, the open end 78 of the air intake pipe 76 of the siphon breaker 34 installed in the top pipe 30 in order to destroy the siphon when the pump is stopped is positioned in the pump building 80 in which the pump 18 is installed. Yes.

  During a siphon break, the sound of the air at the inlet is loud and adversely affects nearby dwellings. Conventionally, measures have been taken, such as providing a silencer for siphon breaks, but since the sound is very loud, the silencer equipment has become extremely excessive.

  According to this example, by providing the open end 78 of the air intake pipe 76 serving as a sound source in the pump building 80, the silencer facility is omitted (or using the soundproofing effect of the building (sound reduction by a wall or the like)) (or This makes it possible to construct a facility that is economical and environmentally friendly.

  The starting method in the pump equipment is shown in FIGS. That is, in this example, when the pump 18 is started (during self-siphoning operation), the operation is performed within the overload resistance of the drive unit 10 (operation exceeding the rated output within the allowable time) and above the rated output. The system is operated at the rated output after the siphon is formed.

  In pump equipment that forms a self-syphon with a pump that has a downward-sloping shaft power, such as an axial flow pump, the power required to form the self-siphon is greater than the power required during normal operation (operation during the planned lift) The rated output of the drive machine is determined by the power at this time. However, when the rated water volume of the pump, which is the majority of the operation (normal operation), does not require such high output, the equipment is designed with a very excessive equipment, and the equipment is not economical. . In addition, starting is performed in units of several minutes per time, and normal operation is several hundred hours per year.

  In addition, a drive machine such as an internal combustion engine or an electric motor is designed so that it can be operated without a failure within an allowable time even in an overload state exceeding a rated output. By completing the self-siphon operation within this allowable time, it is possible to set the rating of the electric motor with the necessary power during the rated operation, and it is possible to improve the economy of the entire equipment. In other words, if the output of the driving machine decreases, it is not necessary to make the specifications of the electrical equipment and auxiliary equipment accompanying it too large, and the overall cost can be reduced.

In combination with the above-described start time shortening method, it is possible to reduce the burden on the driving machine, and to make a more effective equipment configuration.
Further, when starting each of the above-described pump facilities, the operation may be performed within the overload tolerance of the driving machine 10 and at or above the rated rotational speed, and the operation at the rated rotational speed may be performed after the siphon is formed.

  A drive machine such as an internal combustion engine or an electric motor is designed so that it can be operated without a failure within an allowable time even in an overload state exceeding a rated rotational speed. When the siphon is formed, it is possible to increase the discharge water amount during self-siphoning and increase the entrainment amount of air by shortening the start time by making the rotation speed more than the rated rotation speed within this allowable time. Become.

DESCRIPTION OF SYMBOLS 10 Driver 12 Impeller 14 Water absorption tank 18 Pump 20 Siphon piping 20a-20d Flow path 22 Open end 24 Discharge water tank 28 Rising pipe 30 Top piping 30a-30d Channel 32 Drooping pipe 34 Siphon breaker 36 End wide pipe 40 Flow control valve 42 Pressure Total 44, 46 Partition plate 50 Water receiving frame 52 Water level meter 54 Flow path forming surface 60 Curved pipe 62 Inclined portion 64 Swivel flow generating plate 70 Communication pipe 72 Auxiliary pipe 74 Auxiliary pump 76 Air intake pipe 78 Open end 80 Pump building

Claims (3)

In the pump equipment where the siphon piping that forms the siphon is connected to the pump discharge side,
A pump facility characterized in that a water receiving frame having a capacity smaller than that of the discharge water tank and allowing the discharge water to overflow from above the end surface of the opening is disposed at a position covering the periphery of the opening end of the siphon piping and below the end surface. .   The pump equipment according to claim 1, wherein a curved flow path forming surface or an inclined surface for changing a flow direction of the discharged water is provided on a bottom surface of the water receiving frame.   2. The pump equipment according to claim 1, wherein the water receiving frame is arranged so that an overflow end of the water receiving frame is higher than a discharge-side maximum water level.

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