JP2016173043A - Vortex pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vortex pump which prevents occurrence of a restraint accident caused by foreign objects such as sand and achieves improvement of the water pumping ability.SOLUTION: A vortex pump includes: an impeller 60 attached to a main shaft 21 of a vertical type motor 20 and including an upper blade groove 62, a lower blade groove 63, an upper annular part 64, and a lower annular part 65 formed therein; a casing cover 31 which is disposed facing an upper surface of the impeller 60 and forming a narrow gap with the upper surface and includes an upper passage 45 formed at a position facing the upper blade groove 62; a liner part 50 which is disposed facing a lower surface of the impeller 60 and forming a narrow gap with the lower surface and includes a lower passage 52 formed at a position facing the lower blade groove 63; an upper seal part 42 provided at the casing cover 31 and formed into a recessed shape in which an outer peripheral surface of the upper annular part 64 fits; and a lower seal part 51 provided at the liner part 50 and formed into a recessed shape in which an outer peripheral surface of the lower annular part 65 fits.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an eddy current pump that prevents the occurrence of a restraint accident due to foreign matters such as sand during start-up and improves pumping performance.

  The vortex pump discharges the water inside the pump chamber to the discharge side by the rotation of the impeller, generates a negative pressure on the suction side, sucks the air inside the suction pipe, agitates and mixes with the water inside the pump chamber, Self-primed water is circulated by separating the bubbles and releasing them into the atmosphere, and returning the water in the pump chamber to the suction port of the pump unit. The suction side and discharge side of the pump part are sealed with a narrow gap, and water containing bubbles is less likely to flow back to the suction side, so it has excellent self-priming capability and its suction lift is -7 to -8m. In addition, the self-priming time is shorter than that of the centrifugal pump, and the trial operation after construction is simple.

  For this reason, if a check valve is equipped on the suction side, pumping from the well can be completed by self-priming operation just by filling the inside of the pump part called expiratory water with self-priming water. In addition, there is an advantage that it is not necessary to attach a foot valve to the tip of the suction pipe to fill the suction pipe with water, and this pump is suitable for well use.

  Furthermore, the vortex pump has the characteristics of a linear multi-stage pump having impellers corresponding to the number of blades, and a high head can be obtained with a small motor output, which is optimal as a home well pump.

  However, since the power consumption increases as the amount of water becomes smaller, energy saving has been demanded with about 1 or 2 faucets (10 to 20 L / min) used in many homes.

  Thus, by performing constant discharge pressure control using an inverter, it is possible to reduce power consumption on the small water volume side (see, for example, Patent Document 1 (FIG. 5)), but the maximum power point is The flow rate is equivalent to two faucets, and the power consumption is the same as in the past, so the power consumption is the same. The characteristics on the large flow rate side have been improved, and the power consumption has been reduced. .

  On the other hand, the pump efficiency of the vortex pump is greatly influenced by the amount of leakage that flows backward from the discharge side to the suction side through a narrow gap between the impeller, the casing cover, and the liner portion of the casing. For this reason, use a motor with a special structure that can fix the double-sided impeller to the main shaft and move the main shaft in the axial direction, and adjust the impeller so that it does not come into contact with the liner and cover facing each other through a narrow gap. What is made possible is disclosed (for example, see Patent Document 5).

JP-A-10-288185 Japanese Utility Model Publication No. 05-073287 JP 2004-183630 A JP 2012-092927 A Japanese Utility Model Publication No. 05-078989

  The vortex pump described above has the following problems. That is, when a motor having a special structure capable of moving the main shaft in the axial direction is used, the manufacturing cost becomes very high, and further, adjustment of the gap during pump assembly such as movement and fixing of the main shaft is complicated.

  In addition, if the gap is made too small, fine sand contained in the well water remains in the gap, which may cause a restraint accident at the time of startup.

  Furthermore, there was a problem due to the basic structure of the vortex pump. That is, as the fluid flowing in from the suction port advances through the flow path, the turbulence that occurs due to the difference in angular momentum between the root and tip of the blade groove gradually increases and the pumping action increases. At this time, it is considered that the fluid in the blade groove flows out from the blade tip into the annular flow path, and again returns to the root of the blade groove.

  This action is performed simultaneously by a plurality of blades of the impeller, and the turbulent flow is promoted by collision and mixing of fluids in the flow path. As a result, the fluid pressure increases. Then, the fluid in the blade groove that has been rotationally moved from the discharge side to the vicinity of the suction port collides with and mixes with the fluid that flows in from the suction port, resulting in an extremely irregular flow state, and wasteful power loss occurs.

  Furthermore, when it is used for the purpose of pumping well water and the vacuum pressure on the suction side is as high as -6 to -8 m, there is a problem that a pressure drop due to cavitation occurs and the maximum flow rate decreases.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vortex pump that prevents the occurrence of restraint accidents due to foreign matters such as sand and improves the pumping performance.

  In order to solve the above problems and achieve the object, the vortex pump of the present invention is configured as follows.

  An impeller which is inserted into the main shaft of the motor and has an upper blade groove and a lower blade groove, a cylindrical upper ring portion and a lower ring portion formed on its upper and lower surfaces, respectively, and a narrow gap on the upper surface of the impeller And a casing cover in which an upper flow path is formed at a position facing the upper blade groove, and a lower flow path disposed at a position facing the lower blade groove, with a narrow gap on the lower surface. A liner part of the casing formed with, an upper seal part formed in a concave shape with which an outer peripheral surface of the upper annular part is fitted, and a lower circle provided in the liner part. And a lower seal portion formed in a concave shape into which the outer peripheral surface of the ring portion is fitted.

  According to the present invention, it is possible to prevent the occurrence of a constraining accident due to foreign matters such as sand and improve the pumping performance.

The longitudinal cross-sectional view which shows the water supply unit provided with the eddy current pump which concerns on one embodiment of this invention. The longitudinal cross-sectional view which shows the principal part of the eddy current pump. Explanatory drawing which decomposes | disassembles and shows the principal part of the eddy current pump. The side view which shows the principal part of the eddy current pump. The top view which shows the liner part integrated in the eddy current pump. Explanatory drawing which shows the pump characteristic of the eddy current pump. Explanatory drawing which shows the relationship between the flow-path angle of the eddy current pump, and a discharge head.

  FIG. 1 is a longitudinal sectional view showing a water supply unit 10 provided with a vortex pump 30 according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing a main part of the vortex pump 30, and FIG. 4 is a side view showing the main part of the eddy current pump 30, FIG. 5 is a top view showing the liner part incorporated in the eddy current pump 30, and FIG. 6 shows the pump characteristics of the eddy current pump 30. FIG. 7 is an explanatory diagram showing the pump characteristics of the vortex pump 30.

  The water supply unit 10 includes a vertical motor 20, a vortex pump 30 that is rotationally driven by the vertical motor 20, and a control unit 100 that performs variable speed control of the vertical motor 20. The vertical motor 20 has a main shaft (rotating shaft) 21 disposed in the vertical direction, and is coupled to an impeller 60 described later disposed in the vortex pump 30. Hereinafter, the axial direction of the main shaft 21 is referred to as an axial direction.

  The vortex pump 30 includes a casing cover 31 for attaching to the vertical motor 20. The casing cover 31 is fastened to the casing 32, and the upper opening 33 of the casing 32 is covered with a bracket 40 in which an upper surface seal portion 42 that opens downward is formed. Further, the cylindrical opening 34 below the casing 32 is covered with a bottomed cylindrical liner portion 50.

  The bracket 40 has a main shaft 21 disposed in a disc-shaped bracket main body 41 and a concave upper surface seal portion 42 provided on the bracket main body 41, and the main shaft 21 is constituted by a shaft seal fixing portion 43 and a shaft seal rotating portion 44. Sealability is maintained. Furthermore, the bracket body 41 is formed with an upper flow path 45 for guiding water pumped from an upper blade groove 62 described later to a discharge pipe 90 described later.

  In addition, the casing cover 31 and the bracket 40, and the casing 32 and the liner part 50 may be integrally formed.

  In the center of the bottom of the liner portion 50, a concave lower surface seal portion 51 provided in a cylinder projecting upward is provided. Further, the liner 50 is provided with a lower flow path 52 for guiding water pumped from a lower blade groove 63 described later to a discharge pipe 90 described later. Further, as shown in FIG. 4, inside the liner portion 50, facing the side surface of the impeller 60, the axial dimension of the impeller 60 is the same as the dimension of the outer diameter of the lower flow path 52. A cylindrical barrier 70 having substantially the same inner diameter is provided. In FIG. 4, T indicates a discharge port, S1 indicates a suction port (upper side), and S2 indicates a suction port (lower side).

  As shown in FIG. 5, the liner portion 50 includes a draining portion 53 that separates the lower flow path 52 into the suction-side flow path 52 a and the discharge-side flow path 52 b, and a recess is formed in the vicinity of the protruding end of the discharge-side flow path 52 b. A (cavity) 54 is provided (see FIG. 4).

  An impeller 60 is accommodated between the upper surface seal portion 42 of the bracket 40 and the lower surface seal portion 51 of the liner portion 50.

  The impeller 60 includes a disc-shaped main body 61. The main body 61 is provided with an upper surface 61 a facing the bracket 40 and a lower surface 61 b facing the liner portion 50. An upper blade groove 62 is provided on the upper surface 61 a side of the main body 61, and a lower blade groove 63 is provided on the lower surface 61 b side of the main body 61.

  Further, an upper annular portion 64 is provided on the upper surface 61 a side of the impeller 60, and a lower annular portion 65 is provided on the lower surface 61 b side of the main body 61. The outer circumference of the upper annular portion 64 is fitted to the upper surface seal portion 42, and the outer circumference of the lower annular portion 65 is fitted to the lower surface seal portion 51.

  A discharge pipe 90 is connected to the outlet of the vortex pump 30.

  The control unit 100 performs variable speed control of the vertical motor 20 using an inverter. FIG. 6 shows the pump characteristics by the variable speed control at this time.

  In the vortex pump 30 configured as described above, the vertical motor 20 is subjected to variable speed control by the control unit 100.

  The upper and lower horizontal surfaces of the impeller 60 are disposed to face the upper horizontal seal portion 46 of the bracket 40 and the lower horizontal seal portion 56 provided in the liner portion 50 with a narrow gap, but the above gap is the same as the conventional one. Therefore, the possibility that the fine sand contained in the well water remains in the gap is equivalent to the conventional case.

  Further, the impeller 60 is disposed so as to be opposed by a narrow gap by an upper surface seal portion 42 provided on the bracket 40 and a lower surface seal portion 51 provided on the liner portion 50. For this reason, the backflow which makes the path | route the center of the main shaft from the discharge side to the suction side in a path | route can be prevented, and improvement in pumping performance can be aimed at. Moreover, in order to reduce the pumping performance to the same level as before, the impeller dimensions may be changed to reduce power consumption.

  Further, the gap formed by the upper surface seal portion 42 and the lower surface seal portion 51 has a short axial dimension, and the upper surface seal portion 42 is less likely to contain fine sand contained in well water in the gap, Since the fine sand that has entered the lower surface seal portion 51 also falls into the lower surface seal portion 51, it is possible to prevent a restraint accident from occurring at the time of startup.

  Further, since the barrier 70 is provided, the water (fluid) in the upper blade groove 62 and the lower blade groove 63 that has been rotated from the discharge side to the suction side collides with the barrier 70 at a constant distance. Then, while diffusing into the upper blade groove 62 and the lower blade groove 63, the water flowing in from the suction side flows into the upper channel 45 and the lower channel 52 above and below the barrier 70, and then the upper blade. Since the water flows into the roots of the groove 62 and the lower blade groove 63, water having kinetic energy in the two different directions does not collide, and wasteful power loss can be reduced.

FIG. 6 shows the pumping performance, pump efficiency, and power consumption of the conventional eddy current pump by a broken line and the eddy current pump 30 of the present proposal by a solid line. As can be seen from this figure, power loss can be reduced and power consumption can be reduced by improving pump efficiency in the entire flow rate range.
FIG. 7 shows the distribution of the discharge head with respect to the flow path angle of the vortex pump at a suction lift of −8 m. The vortex pump 30 of the present proposal is indicated by a solid line, the conventional vortex pump is indicated by a broken line, and a barrier 70 is provided. It can be seen that the pressure drop in the vicinity of 50 to 70 degrees from the suction side is reduced, and the occurrence of cavitation can be prevented. Therefore, even when used for the purpose of pumping a well with a suction head of about −6 to −8 m, the pressure drop due to cavitation can be reduced. When the water depth is less than 6 m, the rate of decrease in the maximum flow rate is almost the same. Can be reduced to zero.

  Further, a draining portion 53 that separates the lower flow path 52 of the liner portion 50 into the suction side flow path 52a and the discharge side flow path 52b is provided, and a recess (cavity) 54 is provided in the vicinity of the protruding end portion of the discharge side flow path 52b. Thus, the vibration generated by the discharge-side water flow colliding with the tip of the draining portion 53 is reduced from propagating from the liner portion 50 to the casing 32 and the bracket 40, thereby reducing pump noise.

  According to the vortex pump 30 according to the present invention, it is possible to prevent the occurrence of restraint accidents due to foreign matters such as sand and improve the pumping performance.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Water supply unit, 20 ... Vertical motor, 21 ... Main shaft, 30 ... Eddy current pump, 31 ... Casing cover, 32 ... Casing, 40 ... Bracket, 42 ... Top seal part, 45 ... Upper flow path, 50 ... Liner part, 51: Lower seal portion, 52: Lower flow path, 60 ... Impeller, 61a ... Upper surface, 61b ... Lower surface, 62 ... Upper blade groove, 63 ... Lower blade groove, 64 ... Upper ring portion, 65 ... Lower circle Annulus, 70 ... barrier, 90 ... discharge pipe, 100 ... control part.

Claims (3)

An impeller that is inserted into the main shaft of the motor and has an upper blade groove and a lower blade groove, a cylindrical upper ring portion and a lower ring portion formed on the upper and lower surfaces thereof, respectively;
A casing cover having a narrow gap on the upper surface of the impeller and having an upper flow path formed at a position facing the upper blade groove;
A liner portion of the casing, which is disposed opposite to the lower surface with a narrow gap, and in which a lower flow path is formed at a position facing the lower blade groove,
An upper seal portion provided in the casing cover and formed in a concave shape into which an outer peripheral surface of the upper annular portion is fitted; and
An eddy current pump comprising: a lower seal portion provided in the liner portion and formed in a concave shape into which an outer peripheral surface of the lower annular portion is fitted.   The liner portion is provided with a barrier that faces the side surface of the impeller and has an inner diameter that is the same as the axial dimension of the impeller and substantially the same as the outer diameter of the lower flow path. The vortex pump according to claim 1.   The liner portion includes a draining portion that divides the lower flow path into a suction-side flow path and a discharge-side flow path, and a concave portion is provided in the vicinity of the protruding end of the discharge-side flow path. The vortex pump according to claim 1 or 2.