JP2010216352A - Drive water receiving pipe and sand pumping device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive water receiving pipe capable of reducing required power than conventionally and a sand pumping device (jet pump) having the same. <P>SOLUTION: The drive water receiving pipe 4 provided at a tip end of a sand pumping pipe 2 includes a drive water receiving portion 17 having a suction port 4a curved outward, and an enlarged portion 18 extending from the drive water receiving portion 17 and in which its diameter is gradually increased from the upstream side toward the downstream side. Specifically, the suction port 4a of the drive water receiving portion 17 is formed so that a curvature radius R is 0.15d with respect to the diameter d of the drive water receiving portion 17, and the enlarged portion 18 is formed to be enlarged by an inclination angle of γ:5 degrees with respect to a pipe center line. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sand pumping device for sanding a sand settling in a sewage treatment plant or a pumping plant and sinking to the bottom of the pond. In particular, the present invention relates to a jet pump type sand raising device.

  Bucket conveyor systems have been used frequently for sand collection from sand settling basins such as sewage treatment plants, but in recent years, odor countermeasures, simplified maintenance, and equipment cost reduction measures have been used. From the point of view, the adoption of jet pump type sand raising devices is increasing. A jet pump type sand raising device is a type of sand raising device that ejects water at a high pressure from a nozzle (driving water jet nozzle) and sucks and discharges sand using the negative pressure generated at this time. .

  Here, as a technique related to the jet pump type sand raising apparatus, for example, there is a technique described in Patent Document 1. In the sand raising device (jet pump) described in Patent Document 1, the open end of the receiving pipe is arranged so that there is no jet nozzle that jets the jet water flow in the receiving pipe that sucks in an object to be pumped up such as sand. And the opening end of the jet nozzle are arranged at a certain distance in the tube axis direction. And in Patent Document 1, “the structure of the receiving tube is simple, clogging of sand, impurities, etc. is small, and the receiving tube and the jet nozzle are arranged to face each other at a constant interval as described above. Therefore, it is possible to repair each part of the apparatus very easily. "

Japanese Patent No. 2755382

  On the other hand, in a jet pump type sand raising device, a high-pressure jet water flow is used for sucking and discharging sedimentation, so that a driving water pump for generating this jet water flow is required. For this reason, the power is increased as compared with a conventional bucket conveyor type sand raising device. That is, in the jet pump type sand pumping device, power reduction measures for the driving water pump are very important.

  Here, according to the technique described in Patent Document 1, it is possible to prevent clogging of the receiving pipe (driving water receiving pipe provided at the tip of the sand-carrying pipe) due to sand, foreign substances, etc., and to repair each part of the device. It can be done easily. However, in the jet pump described in Patent Document 1, the energy loss (piping) in the receiving pipe part is caused by the contraction of the flow at the suction port (tip part) of the receiving pipe and the expansion of the flow in the pipe diameter enlarging part thereafter. (Pressure loss) is large, which contributes to the power increase of the drive water pump.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a driving water receiving pipe capable of reducing the required power as compared with the conventional one, and a sand raising device (jet pump) including the same. It is to be.

Means and effects for solving the problems

  As a result of intensive studies to solve the above-mentioned problems, the present inventors curved the distal end portion of the driving water receiving portion outward, and formed a widened portion whose diameter gradually increased from the upstream side toward the downstream side. It is found that the energy loss (pipe pressure loss) in the driving water receiving pipe portion can be suppressed lower than before, and the above problem can be solved by this, and the present invention is completed based on this knowledge. It came to do.

  That is, in order to solve the above-mentioned problems, the present invention is a driving water receiving pipe provided at the tip of a sand raising pipe of a sand raising device that sucks sand in a solid-liquid mixed state and raises the sand, and is curved outward. Provided is a driving water receiving pipe comprising a driving water receiving portion having a suction port and a widening portion extending from the driving water receiving portion and gradually increasing in diameter from the upstream side toward the downstream side.

  According to this configuration, by curving the suction port of the driving water receiving portion outward and forming a widened portion whose diameter gradually increases from the upstream side to the downstream side on the downstream side of the driving water receiving portion, these Due to this synergistic effect, it is possible to suppress the generation of a high flow velocity inside the driving water receiving pipe, and as a result, it is possible to suppress the energy loss (pipe pressure loss) in the driving water receiving pipe portion to be lower than before. Thereby, according to the drive water receiving pipe of the present invention, the required power can be reduced as compared with the conventional case.

  Moreover, in this invention, it is preferable that the suction inlet of the said drive water receiving part is formed so that the curvature radius R may be 0.1d or more and 1d or less with respect to the diameter d of the said drive water receiving part. According to this structure, generation | occurrence | production of the high flow velocity inside a drive water receiving pipe can be suppressed more.

  Furthermore, in the present invention, it is preferable that the expanding portion expands at an angle of 1 to 10 degrees with respect to the tube center line. According to this structure, generation | occurrence | production of the high flow velocity inside a drive water receiving pipe can be suppressed more.

  Moreover, according to the 2nd aspect, this invention provides the sand raising apparatus provided with the drive water receiving pipe of this invention. According to this sand pumping device, its power can be reduced more than before, and compared with the conventional jet pump type sand pumping device, energy saving of the sand basin equipment, and consequently the entire sewage treatment facility or pump station equipment. It is possible to provide a sand raising device that contributes to

It is a side view of the sand raising apparatus provided with the drive water receiving pipe which concerns on one Embodiment of this invention. FIG. 2 is a detailed view of a sand raising pipe and a driving water pipe shown in FIG. 1. It is a side view of the sand pipe which concerns on a prior art. It is a contour figure which shows the simulation result of flow velocity distribution. It is a side view which shows the sand pipe and drive water pipe which were used for the pumping experiment. It is a graph which shows a pumping experiment result. It is a graph which shows the pumping experiment result by a small experiment apparatus. It is a detailed side view around the drive water injection nozzle which concerns on other embodiment. It is a BB arrow line view of FIG. 8, and AA sectional drawing.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the following description, a jet pump type sand pumping device is referred to as a “jet pump”.

(Configuration of jet pump)
FIG. 1 is a side view of a jet pump 10 (sand raising apparatus) provided with a driving water receiving pipe 4 according to an embodiment of the present invention. FIG. 2 is a detailed view of the sand raising pipe 2 and the driving water pipe 5 shown in FIG.

  As shown in FIG. 1, the jet pump 10 of the present embodiment has a sand raising pipe 2 disposed in the center of the sand settling pit 3 and a discharge port 1 a that opens opposite to the suction port 4 a of the sand raising pipe 2. And a drive water pipe 5. The driving water pipe 5 is for injecting high-pressure water toward the suction port 4a of the sand raising pipe 2, and the driving water injection nozzle 1 is provided at the tip thereof. The sand raising pipe 2 sucks the sand 20 collected in the sand settling pit 3 in a solid-liquid mixed state by high-pressure water from the driving water pipe 5 and passes through a sand sediment transfer pipe (not shown) connected to the sand raising pipe 2. This is for discharging the sedimentation sand 20 to a sedimentation separator (not shown). A driving water receiving pipe 4 is provided at the tip of the sand raising pipe 2. The jet pump 10 also includes a pressure water pump (not shown), a sand collecting device (not shown), and the like.

  Here, the sand settling pit 3 is formed at the bottom of a sand settling pond provided in a sewage treatment plant or a pumping station. A sand basin is a concrete pond into which sewage that reaches a sewage treatment plant or a pump station flows first, and is provided to remove sand and impurities contained in the sewage. Sand having a specific gravity greater than that of water sinks to the bottom of the settling basin by slowly flowing sewage, and is poured into the settling pit 3 by a sand collecting device (not shown).

  The sand settling pit 3 is made of concrete, and has a trapezoidal shape with an upper opening (a shape that narrows downward) as shown in FIG. 1 in a cross-sectional view. The shape of the sand settling pit 3 is not limited to that shown in FIG. For example, it may have a rectangular shape with an open top in a cross-sectional view.

(Deep sand pipe)
As described above, the sand raising pipe 2 arranged in the center of the sand settling pit 3 sucks the sand settling 20 accumulated in the sand settling pit 3 from the suction port 4a at the tip thereof in a solid-liquid mixed state, It is for discharging the sedimentation sand 20 to a sedimentation separator (not shown) through a connected sedimentation transfer pipe (not shown). The sand raising pipe 2 is a stainless steel pipe (may be a carbon steel pipe), and is arranged at the center of the sand settling pit 3 with its longitudinal direction aligned with the vertical direction.

  As shown in FIG. 2, the sand raising pipe 2 includes a straight pipe 19 and a drive water receiving pipe 4 connected to the straight pipe 19 by welding.

(Drive water pipe)
The straight pipe 19 is piped with its longitudinal direction aligned with the vertical direction. The driving water receiving pipe 4 welded and attached to the upstream end of the straight pipe 19 extends from the driving water receiving part 17 having the suction port 4a curved outward and the driving water receiving part 17 to the upstream. And a widened portion 18 whose diameter gradually increases from the side toward the downstream side.

  Here, the drive water receiving part 17, the spreading part 18, and the straight pipe 19 are all connected (welded) to each other by welding (butt welding). In FIG. 2, the weld line is indicated by w. These members may be connected to each other via a flange (flange connection) or may be screwed (screw connection).

(Drive water receiver)
The drive water receiver 17 is piped with its longitudinal direction aligned with the vertical direction. The tube diameter (bore diameter) of the drive water receiving portion 17 is constant except for the suction port 4a portion. That is, the drive water receiving part 17 is a straight pipe except the suction inlet 4a part. Here, if the tube diameter (portion) of the constant driving water receiving portion 17 except for the suction port 4a portion is d, the suction opening 4a of the driving water receiving portion 17 has a curvature radius R = 0.15d. It is formed to be bent outward. In addition, it is preferable that this curvature radius R is 0.1 d or more and 1 d or less. If the radius of curvature R is too small (less than 0.1 d), the suction resistance of the driving water (high-pressure water from the driving water pipe 5) and the settling sand 20 increases, while the radius of curvature R is too large. However, the effect of reducing the suction resistance is almost the same (even if it is larger than 1d).

  Moreover, the cross-sectional shape of the drive water receiving part 17 is circular. In addition, the cross-sectional shape of the drive water receiving part 17 may be elliptical. Further, the driving water receiving portion 17 is not limited to a pipe whose longitudinal direction is aligned with the vertical direction, and includes, for example, a pipe that is piped at an angle such as obliquely upward (a straight pipe 19 and a spreading portion described later). The same applies to 18).

(Spreading part)
The spreading portion 18 is a member that is piped with its longitudinal direction aligned with the vertical direction, and is welded to the downstream end portion of the driving water receiving portion 17. Further, the expanding portion 18 gradually increases the diameter of the sand raising pipe 2 from the diameter of the driving water receiving portion 17 to the diameter of the straight pipe 19. The gradually increasing pipe diameter means that the pipe diameter gradually increases. Here, the spreading portion 18 is a concentric spreading portion (a line connecting the opening center of the upstream end and the opening center of the downstream end is in the vertical direction).

  Further, in the side view of the spread portion 18, the inclination angle γ between the frusto-conical bus 18a (18b) and the tube center line (vertical direction) is 5 degrees. The inclination angle γ is preferably 1 degree or more and 10 degrees or less. Even if the inclination angle γ is made too small (less than 1 degree), the effect of reducing the pipe pressure loss is hardly changed, and only the driving water receiving pipe 4 is lengthened. On the other hand, if the inclination angle γ is made too large ( This is because the pipe pressure loss at the spread portion 18 becomes large (when it is larger than 10 degrees). In consideration of the balance between the effect of reducing the piping pressure loss at the spreading portion 18 and the length of the driving water receiving pipe 4, the inclination angle γ is more preferably 3 degrees or more and 8 degrees or less.

  The cross-sectional shape of the spread part 18 is circular. The cross-sectional shape of the spreading portion 18 may be an ellipse. Further, the widened portion 18 is not limited to the concentric shape as in the present embodiment, and an eccentric form in which a line connecting the opening center of the upstream end and the opening center of the downstream end is in an oblique direction or the like. It may be a spread part.

(Drive water pipe)
Next, the drive water pipe 5 is for injecting the pressure water toward the suction port 4a of the sand raising pipe 2, and the pressure water flows through the inside thereof. The drive water pipe 5 includes a straight pipe 11 and a drive water injection nozzle 1 connected to the straight pipe 11 by welding. The straight pipe 11 and the drive water injection nozzle 1 are both made of stainless steel (may be made of carbon steel). The drive water pipe 5 is connected to a pressure water pump (not shown) on the upstream side. The pressure water pump (not shown) is one of the devices constituting the jet pump 10.

(Drive water injection nozzle)
The straight pipe 11 is piped with its longitudinal direction aligned with the vertical direction. And the drive water injection nozzle 1 welded and attached to the downstream end part of the said straight pipe 11 is the 1st bending part 12 which changes the flow of a downward direction into a horizontal direction, and the downstream end of the 1st bending part 12 An eccentric reducer portion 13 (first reducer portion) that extends from the portion and decreases in diameter from the upstream side toward the downstream side, and extends from the downstream end portion of the eccentric reducer portion 13 to flow in the horizontal direction upward The second bent portion 14 to be changed into the second bent portion 14, the second reducer portion 15 extending from the downstream end portion of the second bent portion 14 and decreasing in diameter from the upstream side toward the downstream side, and the downstream side of the second reducer portion 15 The nozzle part 16 which forms from the front-end | tip the discharge port 1a which extends from the edge part and opens facing the suction port 4a of the sand pipe 2 is provided.

  Here, the straight pipe 11, the first bent portion 12, the eccentric reducer portion 13, the second bent portion 14, the second reducer portion 15, and the nozzle portion 16 are all connected to each other by welding (butt welding) (welding). It is connected. In FIG. 2, the weld line is indicated by w. These members may be connected to each other via a flange (flange connection), or may be screwed (screw connection) (the same applies to other embodiments described later).

(First bend)
The first bent portion 12 is an elbow member (90 ° elbow) that changes the vertically downward flow to the horizontal direction, and is welded to the downstream end of the straight pipe 11. The pipe diameter of the straight pipe 11 and the pipe diameter of the first bent portion 12 are equal. The straight pipe 11 is not limited to pipes whose longitudinal direction is aligned with the vertical direction, and includes pipes that are piped at an angle such as obliquely downward. In this case, since the first bent portion 12 is a member (tube) that changes the downward flow to the horizontal direction, the first bent portion 12 is not limited to a 90 ° elbow, but a 45 ° elbow or the like. There is also.

(First reducer part)
The eccentric reducer portion 13 is a member whose longitudinal direction is arranged in parallel with the bottom surface of the sand settling pit 3, and is welded to the downstream end portion of the first bent portion 12. Moreover, the eccentric reducer part 13 is reducing the pipe diameter of the drive water pipe 5 from the pipe diameter of the 1st bending part 12 to the pipe diameter of the 2nd bending part 14 mentioned later. Here, in the present embodiment, in the side view of the eccentric reducer portion 13, the inclination angle α between the busbar 13b on the upper side of the truncated cone and the horizontal line is 30 degrees. The inclination angle α is preferably 20 degrees or more and 60 degrees or less. If the inclination angle α is made too small (less than 20 degrees), the eccentric reducer 13 must be lengthened to lower the level of the pipe, so the bottom surface of the sand settling pit 3 needs to be widened. This is because if the angle α is made too large (greater than 60 degrees), the pipe pressure loss of the drive water pipe 5 becomes large.

  Moreover, the cross-sectional shape of the eccentric reducer part 13 is circular, and the opening center is shifted downward as it goes from the upstream side to the downstream side. Here, in FIG. 2, a line connecting the opening centers of the eccentric reducer portions 13 is shown as an opening center line C. The opening center line C is a downward-sloping line. Further, in the present embodiment, in the side view of the eccentric reducer portion 13, the first bent portion 12 is maintained so that the lower busbar 13 a of the truncated cone is horizontal (parallel to the bottom surface of the sand settling pit 3). The tube diameter is reduced from the tube diameter to the tube diameter of the second bent portion 14 described later.

  The opening center line C may be horizontal. That is, the reducer portion 13 is not necessarily eccentric, and may be a concentric reducer portion (concentric reducer portion) whose opening center is the same height from the upstream side toward the downstream side. Moreover, the cross-sectional shape of the eccentric reducer portion 13 may be an ellipse or the like (the same applies to other embodiments described later).

(Second bend)
The second bent portion 14 is an elbow member (90 ° elbow) that changes the flow in the horizontal direction into a vertically upward flow, and is welded to the downstream end of the eccentric reducer portion 13. The tube diameter of the second bent portion 14 is smaller than the tube diameter of the first bent portion 12.

(Second reducer part)
The second reducer portion 15 is a member whose axial center direction is arranged in the vertical direction, and is welded to the downstream end portion of the second bent portion 14. Moreover, the 2nd reducer part 15 is reducing the pipe diameter of the drive water injection nozzle 1 from the pipe diameter of the 2nd bending part 14 to the pipe diameter of the nozzle part 16 mentioned later. Here, the 2nd reducer part 15 is a concentric reducer part (concentric reducer part). In a side view of the second reducer portion 15, the inclination angle β between the generatrix 15a (15b) of the truncated cone and the axial direction (vertical direction) is set to 25 degrees. In addition, it is preferable that inclination | tilt angle (beta) is 20 to 40 degree | times. This is because if the inclination angle β is too small, the position of the nozzle portion 16 becomes high, and if the inclination angle β is too large, the pipe pressure loss of the drive water pipe 5 becomes large.

  The second reducer unit 15 may be an eccentric reducer (second eccentric reducer unit) instead of the concentric reducer. In this case, it is preferable that the busbar 15b on the side located on the outer side of the driving water spray nozzle 1 is aligned with the vertical direction and the busbar 15a on the side located on the inner side is inclined. In this case, the inclination angle β with respect to the vertical direction of the bus 15a on the inner side is preferably 25 degrees or more and 55 degrees or less. Thereby, the flow of the water of a 2nd reducer part becomes smoother, and it can suppress piping pressure loss lower.

(Nozzle part)
The nozzle portion 16 is a nozzle portion that extends from the downstream end portion of the second bent portion 14 via the second reducer portion 15. The nozzle portion 16 is a cylindrical member having the same diameter as the tube diameter of the downstream end portion of the second reducer portion 15 and is welded to the downstream end portion of the second reducer portion 15. Pressure water is jetted from the discharge port 1 a at the tip of the nozzle portion 16 toward the suction port 4 a of the sand pipe 2. The nozzle portion 16 and the second reducer portion 15 can be integrally formed by drawing. Further, a structure in which air can be supplied by attaching the air supply nozzle 6 as shown in FIG. 8 to the tip of the nozzle portion 16 may be used (details will be described later).

(Jet pump operation)
Next, the operation of the jet pump 10 will be described.

  The pressure water pump (not shown) of the jet pump 1 is activated to supply the pressure water (driving water) to the driving water pipe 5 and inject the pressure water from the discharge port 1a toward the suction port 4a of the sand lifting pipe 2. Let The jetted pressure water is sucked into the sand raising pipe 2 from the suction port 4 a together with the sand settling 20 in the sand settling pit 3. Thus, the sand settling 20 sucked into the sand raising pipe 2 is discharged to a sand settling machine (not shown) via a sand settling transfer pipe (not shown) connected to the sand raising pipe 2.

(Verification of the effect of the driving water receiving pipe)
Using two types of φ80 type driving water receiving pipes as examples, the energy loss reduction effect by the driving water receiving pipe 4 according to one embodiment of the present invention was verified.

(simulation)
The driving water receiving tube 4 includes a driving water receiving portion 17 and a spreading portion 18. The driving water receiving portion 17 is a main body of an 80A straight pipe, and the radius of curvature R of the suction port 4a is 12 mm (0.15d). ). On the other hand, a driving water receiving pipe 54 as a comparative example is shown in FIG. As shown in FIG. 3, the sand raising pipe 52 according to the prior art includes a straight pipe 55 and a driving water receiving pipe 54. The driving water receiving tube 54 includes a driving water receiving portion 53 and a spreading portion 56. The driving water receiving portion 53 is a 80A straight pipe (the inlet is not rounded (curved outward)), and the widening portion 56 is a concentric spreading tube of 80A-150A (standard product, tilt angle D: 20 degrees). (The same applies to the pumping experiment described later).

Moreover, the amount of driving water (pressure water amount) sprayed toward the suction port of the sand pipe is set to 2.1 m ³ / min. Table 1 shows the simulation results of the flow velocity distribution. FIG. 4 is a contour diagram showing the simulation result of the flow velocity distribution. FIG. 4A shows a simulation result of the driving water receiving pipe 4 of the present embodiment, and FIG. 4B shows a simulation result of the driving water receiving pipe 54 of the comparative example. In addition, the drive water pipe is the drive water pipe 5 of this embodiment in FIGS. 4 (a) and 4 (b).

  As is clear from the simulation results shown in Table 1, according to the driving water receiving pipe 54 of the present embodiment, it was confirmed that the pumping amount ratio was improved by 46% with respect to the driving water receiving pipe 54 of the comparative example.

  4 (a) and 4 (b) are compared, in the comparative example shown in FIG. 4 (b), there are many places where the flow velocity is high in the drive water receiving pipe 54. This is because the flow suddenly contracts and expands at the driving water receiving portion and the expanding portion, so that the flow is separated from the inner wall of the driving water receiving tube and a vortex is generated, so that the flow path is substantially reduced. This is to reduce the size. This reduction of the flow path results in an increase in pipe pressure loss. On the other hand, in the embodiment of the present invention shown in FIG. 4A, since the reduction of the flow path due to the separation vortex is suppressed, the inside of the driving water receiving pipe 4 is compared with the case of the driving water receiving pipe 54. There are few places with high flow velocity.

(Pumping experiment)
Next, two types of φ80 type driving water receiving pipes (the driving water receiving pipe 4 and the driving water receiving pipe 54) were actually made on a trial basis and a pumping experiment was conducted. FIG. 5 is a side view showing a sand raising pipe and a driving water pipe used in the water pumping experiment. FIG. 5A relates to the driving water receiving pipe 4 of the present embodiment, and FIG. 5B relates to the driving water receiving pipe 54 of the comparative example. As shown in FIG. 5, each of the driving water pipes 65 for supplying the driving water is provided with a nozzle 66 at the tip of a 150A pipe.

FIG. 6 is a graph showing the results of the pumping experiment. Calculate the theoretical power P [kW] of the driving water pump (pressure water pump) necessary to obtain the pumping amount 0.6 m ³ / min from the data of the pumping experiment. The total lift [m] was plotted on the horizontal axis. The circles in FIG. 6 relate to the drive water receiving pipe 4, and the ▲ marks relate to the drive water receiving pipe 54 of the comparative example. The theoretical power P [kW] is obtained by the following formula: driving water amount [m ³ / s] × driving water pump head [m] × density [kg / m ³ ] × gravity acceleration [m / s ² ].

  From the experimental results shown in FIG. 6, by using the driving water receiving pipe 4 of this embodiment, the theoretical power of the driving water pump can be reduced by about 12% (average) compared to the case of the driving water receiving pipe 54. I understood. The motor output [kW] of the driving water pump is ranked for every 20% of power, such as 30/37/45/55/75/90 kW. If it decreases, depending on the specifications of the jet pump, the power of the drive water pump can be lowered by one rank than before.

  Further, the low pressure loss effect (energy loss reduction effect) between the roundness of the suction port of the driving water receiving portion 17 (curvature radius R (= 0.15 d)) and the gradual increase in the diameter of the spread portion 18 (inclination angle γ: 5 degrees). ) Was examined by a small device experiment (1/3 size).

  FIG. 7 is a graph showing the results of a pumping experiment by a small experimental device. Here, a circle in FIG. 6 indicates that the suction port of the driving water receiving portion 17 is rounded (curved outward) with a radius of curvature R = 0.15d, and the widened portion is a standard product (inclination angle D: 20 degrees). It is an experimental result by the driven water receiving pipe. The squares in FIG. 7 are the results of an experiment using a drive water receiving tube that is rounded at the suction port of the drive water receiving portion and has an inclination angle γ of the widened portion 18 of 5 degrees. Moreover, the ▲ mark in FIG. 7 is the result of an experiment using a conventional driving water receiving pipe in which the suction port of the driving water receiving portion is rounded and the widened portion is a standard product (inclination angle D: 20 degrees).

  From the experimental results shown in FIG. 7, the theoretical power of the drive water pump can be reduced by about 5% (average) by making the suction port of the drive water receiving portion curved outward (rounded). all right. In addition, it was found that the theoretical power of the drive water pump can be reduced by about 5% (average) by gradually increasing the diameter of the expanded portion (gradually increasing the diameter of the pipe). Further, in order to compare the experimental result of FIG. 7 with the experimental result of FIG. 6 described above, the suction port of the driving water receiving part is curved outward and the diameter of the widened part is gradually increased (the pipe diameter is gradually reduced). (Experimental results in FIG. 6), a good result of about 2% was obtained as compared with the case where each was performed alone (experimental results in FIG. 7). That is, it can be seen that there is a synergistic effect by curving the suction port of the driving water receiving portion outward and gradually increasing the diameter of the expanding portion (gradually widening the tube diameter).

  As described above, the expanding portion 18 whose diameter is gradually increased from the upstream side to the downstream side is curved to the outside of the suction port 4a of the driving water receiving portion 17 and downstream of the driving water receiving portion 17. By forming the driving water receiving pipe 4 to be formed, these synergistic effects can further suppress the generation of a high flow velocity inside the driving water receiving pipe 4, and as a result, energy loss ( Pipe pressure loss) can be kept lower than before. Thereby, according to the drive water receiving pipe of the present invention, the power of the drive water pump can be reduced as compared with the conventional case.

  In addition, by curving the suction port 4a of the drive water receiving part 17 to the outside, the suction area is increased, and as a result, there is an effect that the operation time of the drive water pump can be shortened.

(Verification of the effect of the driving water injection nozzle)
The drive water injection nozzle 1 according to the present embodiment and the drive water injection nozzle according to the comparative example were prototyped, and a performance comparison test of the drive water injection nozzle was performed.

(Experimental result)
The driving water jet nozzle 1 is, in order from the upstream side, 150A straight pipe 11 (vertical pipe), 150A / 90 ° elbow first bent portion 12, 150A-80A eccentric reducer portion 13, 80A / 90 ° elbow first. It was set as the nozzle which consists of the 2 bending part 14, the 2nd reducer part 15 of 80A-36mm, and the nozzle part 16 of 36 mm in diameter.

  On the other hand, the driving water injection nozzle according to the comparative example has a 150A straight pipe (vertical pipe), a 150A / 90 ° elbow, a 150A straight pipe (horizontally arranged short pipe), 150A / 90 ° in order from the upstream side. The nozzle was composed of an elbow, a 150A-36 mm concentric reducer, and a nozzle part having a diameter of 36 mm.

  And the pressure loss of the above-mentioned two types of drive water jet nozzles was measured. As a result, it was found that the pressure loss can be kept sufficiently low according to the drive water jet nozzle 1. In addition, according to the drive water spray nozzle 1 of this embodiment, the level of the discharge port 1a can be made at least 100 mm lower than the drive water spray nozzle according to the comparative example.

  That is, by reducing (squeezing) the diameter of the drive water jet nozzle 1 in two steps as in the present embodiment, the pipe pressure loss of the drive water pipe can be kept sufficiently low while reducing the level of the discharge port 1a. it can.

  Although the reduction of the diameter of the drive water injection nozzle in three stages or more (squeezing) was also considered, the pipe pressure loss is greatly reduced as compared to the case of reducing (squeezing) in two stages as in this embodiment. Was not recognized. On the other hand, as the number of diameters is increased, the level of the discharge port 1a tends to gradually increase. That is, in consideration of lowering the level of the discharge port 1a, when reducing the diameter in a plurality of stages, it is preferable to reduce (squeeze) the diameter of the drive water spray nozzle in two stages.

  Further, by disposing the drive water pipe 5 below the sand pumping pipe 2 so as to be the discharge port 1a opening facing the suction port 4a of the sand pumping pipe 2, the bottom of the sand pit (the driving water pipe 5 A dead space (a place where sedimentation tends to accumulate) is formed in the bottom). However, according to the drive water jet nozzle 1 (jet pump 10) of the present embodiment, the discharge port with the pipe pressure loss of the drive water pipe 5 kept low by the eccentric reducer portion 13 whose diameter decreases from the upstream side toward the downstream side. The position (level) of 1a can be lowered. Here, by keeping the pipe pressure loss of the driving water pipe 5 low, the momentum of the jet water flow from the driving water pipe 5 injected from the discharge port 1a toward the suction port 4a of the sand raising pipe 2 does not drop (keep the momentum high). be able to). From another point of view, the power of the drive water pump can be kept low.

  In addition, since the position (level) of the discharge port 1a of the driving water pipe 5 can be lowered, the position (level) of the suction port 4a of the sand pumping pipe 2 can also be lowered. The distance between the inlet 2a of the pipe 2 can be shortened. Accordingly, even if the driving water pipe 5 is disposed below the sand raising pipe 2 and a dead space (a place where the sand is easily collected) is formed at the bottom of the sand settling pit 3, a decrease in the sand raising efficiency of the sand settling 20 is prevented. be able to.

  In addition, since the suction force extends to a deeper position of the sand settling pit 3 by shortening the distance between the bottom surface of the sand settling pit 3 and the suction port 4a of the sand raising pipe 2, there is a dead space at the bottom of the sand settling pit 3. Even if it is not, it can suck in more sand settling 20 (it can reduce the unsucked sand set 20 after operation of jet pump 1).

  In the present embodiment, in the side view of the eccentric reducer 13, the diameter is reduced so that the lower generatrix 13a of the truncated cone is horizontal, so the position (level) of the discharge port 1a of the drive water pipe 5 Can be lowered.

(Another embodiment of the driving water jet nozzle)
FIG. 8 is a detailed side view around the drive water jet nozzle 21 according to another embodiment. 9 is a BB arrow view and an AA cross-sectional view of FIG. In the following description, differences from the above-described drive water injection nozzle 1 will be mainly described. The same members as those constituting the jet pump 10 are denoted by the same reference numerals. As in this embodiment, the diameter of the drive water spray nozzle may be reduced (throttle) in one step.

  As shown in FIG. 8, the drive water pipe 7 of this embodiment includes a straight pipe 11 and a drive water injection nozzle 21 connected to the straight pipe 11 by welding.

(Eccentric reducer)
The difference between the eccentric reducer portion 23 of the present embodiment and the eccentric reducer portion 13 is the tube diameter and the tube length of the downstream end portion. The eccentric reducer portion 23 of the present embodiment has a tube diameter at the downstream end smaller than that of the eccentric reducer portion 13, and as a result, the tube length is longer. The inclination angle α is set to 30 degrees as in the case of the eccentric reducer 13. Further, similarly to the eccentric reducer portion 13, the inclination angle α is preferably not less than 20 degrees and not more than 60 degrees. If the inclination angle α is too small, the eccentric reducer 23 must be lengthened to lower the level of the tube, so the bottom surface of the sand pit 3 needs to be widened. On the other hand, if the inclination angle α is too large, This is because the pipe pressure loss of the drive water pipe 25 becomes large.

  Further, as shown in FIG. 9A as viewed from the direction indicated by arrows BB in FIG. 8, the bus bars 23 c and 23 d on both sides of the truncated cone in the plan view of the eccentric reducer 23 are the eccentric reducer 13. (The same applies to the eccentric reducer 13).

(Second bend)
The difference between the second bent portion 24 of the present embodiment and the second bent portion 14 is the pipe diameter. The tube diameter of the second bent portion 24 of the present embodiment is smaller than the tube diameter of the first bent portion 12 and smaller than the tube diameter of the second bent portion 14.

(Nozzle part)
The nozzle portion 25 of this embodiment is directly welded to the downstream end portion of the second bent portion 24. In addition, the nozzle part 25 and the 2nd bending part 14 can also be integrally molded by the bending process of a pipe | tube.

  Here, the air supply nozzle 6 is attached to the tip of the nozzle portion 25 by screwing or welding. As shown in FIG. 9B, the air supply nozzle 6 has a cylindrical portion 6a and a throttle portion 6b. The inner diameter of the cylindrical portion 6a is larger than the outer diameter of the nozzle portion 25, and the aperture diameter of the throttle portion 6b is reduced as it goes upward. Further, the upper end of the throttle portion 6b is located above the upper end of the discharge port 1a. The downstream end of the air supply pipe 8 is connected to the side surface of the cylindrical portion 6a. An air supply device (air compressor) (not shown) is connected to the air supply pipe 8 on the upstream side. The air supply nozzle 6 is made of stainless steel (may be made of carbon steel). Further, the outer diameter of the air supply nozzle 6 is smaller than the inner diameter of the suction port 4a of the sand pipe 2. The air supply pipe 8 is piped along the drive water pipe 7. Note that an air supply device may not be connected to the air supply pipe 8, and the upstream end of the air supply pipe 8 may be open to the atmosphere.

(About air supply nozzle)
When a driving water pump (not shown) is activated, pressure water (driving water) is supplied to the driving water pipe 7, and when the pressure water is injected from the discharge port 1a toward the suction port 4a of the sand pipe 2, The pressurized water is sucked into the sand raising pipe 2 together with the sand settling 20 in the sand settling pit 3.

  Here, pressure water is jetted from the discharge port 1a of the drive water pipe 7 toward the suction port 4a of the sand pumping pipe 2, and an air supply device (not shown) is activated, and the sand pumping pipe 2 from the air supply nozzle 6 is activated. Air is supplied toward the suction port 4a. By supplying air from the air supply nozzle 6, the layer of the sand settling 20 between the discharge port 1a and the suction port 4a and in the vicinity thereof is easily broken, which helps sanding at the initial stage of startup. The supply of air from the air supply nozzle 6 may be performed only at the start of the driving water pump (pressure water pump (not shown)) or continuously during the operation of the driving water pump (not shown). As shown in FIG. 9B, the tip of the air supply nozzle 6 is squeezed (throttle portion 6b), so that the air jetted upward from the air supply nozzle 6 is prevented from spreading obliquely upward, Since it rises with a flow that concentrates in the center of the suction port 4a of the sand pumping pipe 2, the layer of the sand settling 20 between the discharge port 1a and the suction port 4a and the vicinity thereof is easily broken, that is, the sand pumping efficiency of the sand settling 20 decreases. Can be prevented.

  In addition, by supplying air from the air supply nozzle 6 to the sand raising pipe 2, the sand settling 20 sucked into the sand raising pipe 2 and transferred through the sand settling transfer pipe is washed. In addition, there is an effect that the resistance in the pipe in the sand raising pipe 2 and the sand settling pipe is reduced and the sand raising efficiency is improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. .

  For example, in the above-described embodiment, an example in which the diameter of the suction port 4a of the driving water receiving pipe 4 is gradually increased in one stage (only by the widened portion 18) has been shown, but the driving water receiving pipe is divided into two or more stages. The diameter of the suction port may be gradually increased.

  In addition, among the driving water jet nozzles provided at the tip of the driving water pipe, the portion parallel to the bottom surface of the sand settling pit is a reducer part whose diameter decreases from the upstream side toward the downstream side. The position (level) of the discharge port of the drive water pipe can be lowered while keeping the pipe pressure loss at a low level. That is, the diameter of the drive water injection nozzle may be reduced (throttle) in multiple stages of three or more stages. .

1: Drive water jet nozzle 1a: Discharge port 2: Sand pumping pipe 4a: Suction port 3: Sedimentation pit 4: Drive water receiving pipe 10: Jet pump (sand pumping device)
17: Drive water receiving part 18: Spreading part

Claims (4)

A driving water receiving pipe provided at the tip of a sand raising pipe of a sand raising device that sucks sand in a solid-liquid mixed state and raises the sand,
A driving water receiver having a suction port curved outward;
An extended portion extending from the driving water receiving portion and gradually increasing in diameter from the upstream side toward the downstream side,
A drive water receiving tube comprising:   The suction port of the driving water receiving part is formed so that a curvature radius R is 0.1d or more and 1d or less with respect to a diameter d of the driving water receiving part. Drive water receiver tube.   The drive water receiving pipe according to claim 1, wherein the spreading portion is spread at an angle of 1 to 10 degrees with respect to the pipe center line. A sand raising device comprising the drive water receiving pipe according to any one of claims 1 to 3.