EP3850219B1 - Self-priming centrifugal pump - Google Patents
Self-priming centrifugal pump Download PDFInfo
- Publication number
- EP3850219B1 EP3850219B1 EP19765816.4A EP19765816A EP3850219B1 EP 3850219 B1 EP3850219 B1 EP 3850219B1 EP 19765816 A EP19765816 A EP 19765816A EP 3850219 B1 EP3850219 B1 EP 3850219B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- suction conduit
- pumping chamber
- conduit
- pump body
- auxiliary suction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- 238000005086 pumping Methods 0.000 claims description 30
- 238000007493 shaping process Methods 0.000 claims description 4
- 230000000903 blocking effect Effects 0.000 claims 1
- 239000007788 liquid Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- 238000012423 maintenance Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D9/00—Priming; Preventing vapour lock
- F04D9/04—Priming; Preventing vapour lock using priming pumps; using booster pumps to prevent vapour-lock
- F04D9/06—Priming; Preventing vapour lock using priming pumps; using booster pumps to prevent vapour-lock of jet type
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
- F04D15/0005—Control, e.g. regulation, of pumps, pumping installations or systems by using valves
Definitions
- the present invention relates to a self-priming centrifugal pump.
- the known self-priming centrifugal pumps comprise a substantially cylindrical shaped body having a front-facing liquid suction opening and an outlet opening located on an upper side.
- the impeller group adapted to be rotated by a suitable motor member, generally of the electric type, is housed inside a pumping chamber, which is associated with the pump body.
- the ejector group is arranged inside the cavity defined by the pump body.
- the ejector group comprises an ejection nozzle and a collecting suction conduit shaping a divergent profile.
- the collecting suction conduit is connected on one side to the suction opening and on the opposite side to the inlet of the impeller group, coaxially thereto.
- the recirculation of the liquid is carried out through the ejection nozzle; the liquid, on exiting from the pumping chamber of the impeller group, fills the internal cavity of the pump body.
- the total flow rate passing through the impeller group is partly delivered through the outlet opening and partly recycled through the ejection nozzle thanks to the Venturi effect produced in the collecting suction conduit.
- Patent EP 0.401.670 illustrates, for example, a self-priming centrifugal pump of this type.
- centrifugal pumps of the aforementioned type The main problem in the use of centrifugal pumps of the aforementioned type is the performance decay that occurs when a certain value of the flow rate is reached. This effect is caused by the incipient cavitation that is generated in the area surrounding the ejection nozzle at the opening of the Venturi tube. It follows that the maximum flow rate achievable in centrifugal pumps of the aforementioned type finds a limit caused by the aforementioned performance decay.
- FIGS 2 and 3 illustrate in graphical form, with the dotted lines H and P, the variation respectively of the hydraulic head and the percentage efficiency of a known self-priming centrifugal pump as a function of the flow rate. It is clearly visible that once a predetermined flow rate value Q' is reached, both the head and the efficiency of the pump fall. Ultimately, this Q' value represents the maximum flow rate achievable in centrifugal pumps of the aforementioned type.
- US patent 2,634,680 illustrates a self-priming centrifugal pump, selectively operable in a first mode (so-called shallow-well system) and a second mode (so-called deep well system).
- the pump provides for a by-pass conduit, through which the liquid may flow from the outlet opening to the impeller group, without engaging the ejector group.
- GB 397,035 discloses a further embodiment of a self-priming centrifugal pump equipped with a by-pass conduit.
- the aim of the present invention is to solve the aforementioned problems by devising a self-priming centrifugal pump, which allows the maximum achievable flow rate to be increased while maintaining high levels of performance.
- a further object of the present invention is to provide a self-priming centrifugal pump, which ensures the maintenance of the maximum pressure.
- Another object of the invention is to provide a self-priming centrifugal pump which allows the efficiency of the pumping group to be improved.
- Still another object of the invention is to provide a self-priming centrifugal pump of simple constructive and functional conception, provided with a certainly reliable operation, of versatile use, as well as of relatively economical cost.
- the self-priming centrifugal pump comprises a pump body having an inner cavity having a longitudinal axis arranged in a horizontal position in use configuration; a pumping chamber associated with said pump body and having at a frontal part thereof an axial inlet opening; an ejector group which extends inside said inner cavity of the pump body according to said longitudinal axis and which is axially associated with said pumping chamber, within said inner cavity of the pump body being defined an upper zone and a lower zone with respect to said ejector group; a suction opening made on a frontal surface of said pump body at said upper zone located above said ejector group; an auxiliary suction conduit arranged inside said inner cavity of the pump body, at said upper zone with respect to said ejector group, and configured for directly connecting said suction opening with said inlet opening of the pumping chamber.
- an impeller group provided with an axial hub adapted to be associated with a motor shaft coaxial thereto according to said longitudinal axis is arranged.
- Said ejector group comprises an ejection nozzle and a collecting suction conduit shaping a divergent profile, connected, at the end of the wider section thereof, to said inlet opening of the pumping chamber.
- said divergent profile is made up of a first portion with constant inclination and a second section with increasing inclination which engages in said axial inlet opening of the pumping chamber.
- said auxiliary suction conduit opens into the upper part of said first portion at a constant inclination of the collecting suction conduit.
- the pump comprises a non-return valve arranged inside said auxiliary suction conduit.
- said auxiliary suction conduit has a substantially rectilinear arrangement.
- said auxiliary suction conduit is inclined at an angle with respect to said longitudinal axis of the pump body.
- said angle is approximately 45°.
- said auxiliary suction conduit has a slightly curved upper portion which may be inserted into the top of said feeding conduit in front of said suction opening.
- said upper portion of the auxiliary suction conduit engages at the top of said feeding conduit according to an axis substantially parallel to the horizontal axis of said suction opening.
- said collecting suction conduit is connected, at said ejection nozzle, to a feeding conduit which extends substantially in a radial direction at said upper zone of the pump body and is connected to said suction opening at the top.
- said feeding conduit opens into a portion of said collecting suction conduit arranged in a toroidal shape around said ejection nozzle.
- the pressure at the region of said collecting suction conduit near the mouth of said inlet opening of the pumping chamber is lower than the pressure at the top of said auxiliary suction conduit.
- the non-return valve opens the said auxiliary suction conduit, allowing the pump to achieve a high flow rate and efficiency.
- the pressure at the zone of said collecting suction conduit near the mouth of said inlet opening of the pumping chamber is higher than the pressure at the top of said auxiliary suction conduit.
- the non-return valve closes the said auxiliary suction duct, allowing the pump to maintain a high head.
- the centrifugal pump 1 indicates the self-priming centrifugal pump according to the invention.
- the centrifugal pump 1 comprises a pump body 10, which shapes an inner cavity 11.
- the pump body 10 defines the casing of the operating members of the pump.
- the pump body 10 has for example a substantially cylindrical shape and has a longitudinal axis A arranged in a horizontal position in the use configuration.
- the longitudinal axis A represents the motor axis of the rotating parts of the pump.
- the longitudinal axis A divides the inner cavity 11 of the pump body 10 into an upper zone S and in a lower zone I.
- a suction opening 12 is made on a frontal surface 13 of the pump body 10.
- the suction opening 12 is arranged at the upper zone S of the pump body 10 located above the longitudinal axis A.
- An outlet opening 14 is made on an upper surface 15 of the pump body 10.
- the outlet opening 14 is in communication with the upper zone S of the inner cavity 11 of the pump body 10.
- the outlet opening 14 is arranged radially with respect to the longitudinal axis A of the pump body 10.
- a pumping chamber 20 is associated with the pump body 10.
- the pumping chamber 20 has an axial inlet opening 21 at the frontal part thereof, facing the inner cavity 11 of the pump body 10.
- the pumping chamber 20 substantially closes the inner cavity 11 of the pump body 10 on the opposite side the frontal surface 13.
- an impeller group 22 is arranged, of a known shape; the impeller group 22 is provided with an axial hub 23, which is axially associated with a motor shaft 24 coaxial thereto.
- the motor shaft 24 is adapted to be rotated by a motor member 25, for example of an electric type, represented only partially in the figure.
- An ejector group 30 is axially associated with the pumping chamber 20 and extends inside the inner cavity 11 of the pump body 10.
- the ejector group 30 comprises an ejection nozzle 31 and a collecting suction conduit 32 shaping a divergent profile.
- the collecting suction conduit 32 is connected at the end of the wider section thereof to the mouth of the inlet opening 21 of the pumping chamber 20; at the opposite end, the collecting suction conduit 32 is connected to a feeding conduit 33 which extends substantially in a radial direction at the upper zone S of the pump body 10 and at the top is connected to the suction opening 12.
- the feeding conduit 33 opens into a portion of collecting suction conduit 32 arranged in a toroidal shape around the ejection nozzle 31.
- the ejector group 30 is made up of a rear part 30a and a frontal part 30b.
- the rear part 30a substantially shapes the collecting suction conduit 32 and the feeding conduit 33;
- the frontal part 30b is constituted by a cover which frontally closes the rear part 30a and shapes the ejection nozzle 31 and a sleeve 36 which is inserted tightly in the suction opening 12.
- the self-priming centrifugal pump has an auxiliary suction conduit 34 adapted to put the suction opening 12 in direct communication with the inlet opening 21 of the pumping chamber 20.
- the auxiliary suction conduit 34 has a substantially rectilinear arrangement and is contained at said upper zone S of the inner cavity 11 of the pump body 10 located above the longitudinal axis A.
- the auxiliary suction conduit 34 is inclined at an angle of predetermined width with respect to the longitudinal axis A; this angle is included for example in a range around 45°, depending on the size of the pump.
- the auxiliary suction conduit 34 has a slightly curved portion at its top, which is inserted into the top of the feeding conduit 33 in front of the suction opening 12.
- the upper portion of the auxiliary suction conduit 34 engages in the top of the feeding conduit 33 with its axis substantially parallel to the horizontal axis of the suction opening 12.
- a non-return valve 35 is arranged inside the auxiliary suction conduit 34, in a substantially central position.
- the non-return valve 35 is adapted to close the auxiliary suction conduit 34 when the pressure at the area of the collecting suction conduit 32 near the mouth of the inlet opening 21 of the pumping chamber 20 is higher than the pressure at the top of the auxiliary suction conduit 34.
- the total flow rate passing through the impeller group 22 is introduced into the inner cavity 11 of the pump body 10. This total flow is partly delivered through the outlet opening 14 and partly drawn back into circulation through the ejection nozzle 31, thanks to the Venturi effect, which is produced in the collecting suction conduit 32.
- the non-return valve 35 opens the auxiliary suction conduit 34 and allows the liquid to pass directly from the suction opening 12 to the inlet of the pumping chamber 20. In this way cavitation phenomena are avoided in the area surrounding the ejection nozzle, at the inlet of the collecting suction conduit 32, while allowing the overall flow entering the impeller group 22 to increase up to the desired value.
- the pressure at the area of the collecting suction conduit 32 near the mouth of the inlet opening 21 of the pumping chamber 20 is lower than the pressure at the top of the auxiliary suction conduit 34 and therefore the non-return valve 35 opens the auxiliary suction conduit 34. In this way, a greater flow rate and greater efficiency are obtained than with a traditional self-priming pump.
- the pressure at the area of the collecting suction conduit 32 near the mouth of the inlet opening 21 of the pumping chamber 20 is higher than the pressure at the top of the auxiliary suction conduit 34 and therefore the non-return valve 35 closes the auxiliary suction conduit 34. In this way, a greater prevalence is obtained compared to a traditional centrifugal pump.
- the self-priming centrifugal pump according to the present invention has a trend of the head and of the efficiency which maintain relatively high values for flows significantly higher than the traditional pumps, as shown in the graphs of Figures 2 and 3 where it is indicated with the continuous lines h and p the variation respectively of the head and the percentage efficiency of the pump in question according to the flow rate, compared to that of a traditional pump represented with the dotted lines H and P. It should be noted that the head and efficiency of the pump according to the present invention maintain a satisfactory value even when the Q' value, which represents the maximum flow rate achievable in the centrifugal pumps of the traditional type, is exceeded.
- the self-priming centrifugal pump according to the present invention thus reaches the purpose of increasing the maximum flow rate achievable while maintaining high levels of performance.
- the used materials as well as the shape and the dimensions, may vary depending on requirements.
Description
- The present invention relates to a self-priming centrifugal pump.
- The use of self-priming centrifugal pumps which provide for an ejector group connected on one side to the suction of the liquid and on the opposite side to the inlet of the impeller group, coaxially thereto, is currently known.
- More specifically, the known self-priming centrifugal pumps comprise a substantially cylindrical shaped body having a front-facing liquid suction opening and an outlet opening located on an upper side. The impeller group, adapted to be rotated by a suitable motor member, generally of the electric type, is housed inside a pumping chamber, which is associated with the pump body.
- The ejector group is arranged inside the cavity defined by the pump body. The ejector group comprises an ejection nozzle and a collecting suction conduit shaping a divergent profile. The collecting suction conduit is connected on one side to the suction opening and on the opposite side to the inlet of the impeller group, coaxially thereto. The recirculation of the liquid is carried out through the ejection nozzle; the liquid, on exiting from the pumping chamber of the impeller group, fills the internal cavity of the pump body.
- In use, the total flow rate passing through the impeller group is partly delivered through the outlet opening and partly recycled through the ejection nozzle thanks to the Venturi effect produced in the collecting suction conduit.
- Patent
EP 0.401.670 illustrates, for example, a self-priming centrifugal pump of this type. - The main problem in the use of centrifugal pumps of the aforementioned type is the performance decay that occurs when a certain value of the flow rate is reached. This effect is caused by the incipient cavitation that is generated in the area surrounding the ejection nozzle at the opening of the Venturi tube. It follows that the maximum flow rate achievable in centrifugal pumps of the aforementioned type finds a limit caused by the aforementioned performance decay.
-
Figures 2 and 3 illustrate in graphical form, with the dotted lines H and P, the variation respectively of the hydraulic head and the percentage efficiency of a known self-priming centrifugal pump as a function of the flow rate. It is clearly visible that once a predetermined flow rate value Q' is reached, both the head and the efficiency of the pump fall. Ultimately, this Q' value represents the maximum flow rate achievable in centrifugal pumps of the aforementioned type. -
US patent 2,634,680 illustrates a self-priming centrifugal pump, selectively operable in a first mode (so-called shallow-well system) and a second mode (so-called deep well system). The pump provides for a by-pass conduit, through which the liquid may flow from the outlet opening to the impeller group, without engaging the ejector group. -
GB 397,035 - However, these solutions are not exempt from improvements.
- The aim of the present invention is to solve the aforementioned problems by devising a self-priming centrifugal pump, which allows the maximum achievable flow rate to be increased while maintaining high levels of performance.
- Within this aim, a further object of the present invention is to provide a self-priming centrifugal pump, which ensures the maintenance of the maximum pressure.
- Another object of the invention is to provide a self-priming centrifugal pump which allows the efficiency of the pumping group to be improved.
- Still another object of the invention is to provide a self-priming centrifugal pump of simple constructive and functional conception, provided with a certainly reliable operation, of versatile use, as well as of relatively economical cost.
- The aforementioned objects are achieved, according to the present invention, by the self-priming centrifugal pump according to claim 1.
- The self-priming centrifugal pump comprises a pump body having an inner cavity having a longitudinal axis arranged in a horizontal position in use configuration; a pumping chamber associated with said pump body and having at a frontal part thereof an axial inlet opening; an ejector group which extends inside said inner cavity of the pump body according to said longitudinal axis and which is axially associated with said pumping chamber, within said inner cavity of the pump body being defined an upper zone and a lower zone with respect to said ejector group; a suction opening made on a frontal surface of said pump body at said upper zone located above said ejector group; an auxiliary suction conduit arranged inside said inner cavity of the pump body, at said upper zone with respect to said ejector group, and configured for directly connecting said suction opening with said inlet opening of the pumping chamber.
- Inside said pumping chamber an impeller group provided with an axial hub adapted to be associated with a motor shaft coaxial thereto according to said longitudinal axis is arranged.
- Said ejector group comprises an ejection nozzle and a collecting suction conduit shaping a divergent profile, connected, at the end of the wider section thereof, to said inlet opening of the pumping chamber.
- Preferably, said divergent profile is made up of a first portion with constant inclination and a second section with increasing inclination which engages in said axial inlet opening of the pumping chamber.
- Preferably, said auxiliary suction conduit opens into the upper part of said first portion at a constant inclination of the collecting suction conduit.
- According to the invention, the pump comprises a non-return valve arranged inside said auxiliary suction conduit.
- Advantageously, said auxiliary suction conduit has a substantially rectilinear arrangement.
- Preferably, said auxiliary suction conduit is inclined at an angle with respect to said longitudinal axis of the pump body.
- Preferably, said angle is approximately 45°.
- Preferably, said auxiliary suction conduit has a slightly curved upper portion which may be inserted into the top of said feeding conduit in front of said suction opening.
- Preferably, said upper portion of the auxiliary suction conduit engages at the top of said feeding conduit according to an axis substantially parallel to the horizontal axis of said suction opening.
- Advantageously, said collecting suction conduit is connected, at said ejection nozzle, to a feeding conduit which extends substantially in a radial direction at said upper zone of the pump body and is connected to said suction opening at the top.
- Preferably, said feeding conduit opens into a portion of said collecting suction conduit arranged in a toroidal shape around said ejection nozzle.
- Advantageously, at a high flow rate, the pressure at the region of said collecting suction conduit near the mouth of said inlet opening of the pumping chamber is lower than the pressure at the top of said auxiliary suction conduit.
- In this way, the non-return valve opens the said auxiliary suction conduit, allowing the pump to achieve a high flow rate and efficiency.
- Advantageously, at a low flow rate, the pressure at the zone of said collecting suction conduit near the mouth of said inlet opening of the pumping chamber is higher than the pressure at the top of said auxiliary suction conduit.
- In this way, the non-return valve closes the said auxiliary suction duct, allowing the pump to maintain a high head.
- The details of the invention will become more apparent from the detailed description of a preferred embodiment of the self-priming centrifugal pump according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, where:
-
Figure 1 shows an axial section view of the self-priming centrifugal pump; -
Figures 2 and 3 show a graph respectively of the head and the efficiency of the pump as a function of the flow rate. - With particular reference to these figures, the reference numeral 1 indicates the self-priming centrifugal pump according to the invention. The centrifugal pump 1 comprises a
pump body 10, which shapes aninner cavity 11. Thepump body 10 defines the casing of the operating members of the pump. - The
pump body 10 has for example a substantially cylindrical shape and has a longitudinal axis A arranged in a horizontal position in the use configuration. As specified in the following, the longitudinal axis A represents the motor axis of the rotating parts of the pump. - The longitudinal axis A divides the
inner cavity 11 of thepump body 10 into an upper zone S and in a lower zone I. - A
suction opening 12 is made on afrontal surface 13 of thepump body 10. Thesuction opening 12 is arranged at the upper zone S of thepump body 10 located above the longitudinal axis A. - An outlet opening 14 is made on an
upper surface 15 of thepump body 10. The outlet opening 14 is in communication with the upper zone S of theinner cavity 11 of thepump body 10. The outlet opening 14 is arranged radially with respect to the longitudinal axis A of thepump body 10. - A
pumping chamber 20 is associated with thepump body 10. Thepumping chamber 20 has an axial inlet opening 21 at the frontal part thereof, facing theinner cavity 11 of thepump body 10. Thepumping chamber 20 substantially closes theinner cavity 11 of thepump body 10 on the opposite side thefrontal surface 13. - Inside the
pumping chamber 20 animpeller group 22 is arranged, of a known shape; theimpeller group 22 is provided with anaxial hub 23, which is axially associated with amotor shaft 24 coaxial thereto. Themotor shaft 24 is adapted to be rotated by amotor member 25, for example of an electric type, represented only partially in the figure. - An
ejector group 30 is axially associated with the pumpingchamber 20 and extends inside theinner cavity 11 of thepump body 10. Theejector group 30 comprises anejection nozzle 31 and a collectingsuction conduit 32 shaping a divergent profile. The collectingsuction conduit 32 is connected at the end of the wider section thereof to the mouth of the inlet opening 21 of the pumpingchamber 20; at the opposite end, the collectingsuction conduit 32 is connected to afeeding conduit 33 which extends substantially in a radial direction at the upper zone S of thepump body 10 and at the top is connected to thesuction opening 12. - Preferably the feeding
conduit 33 opens into a portion of collectingsuction conduit 32 arranged in a toroidal shape around theejection nozzle 31. - In the illustrated embodiment, the
ejector group 30 is made up of arear part 30a and afrontal part 30b. Therear part 30a substantially shapes the collectingsuction conduit 32 and the feedingconduit 33; thefrontal part 30b is constituted by a cover which frontally closes therear part 30a and shapes theejection nozzle 31 and asleeve 36 which is inserted tightly in thesuction opening 12. - According to the present invention, the self-priming centrifugal pump has an
auxiliary suction conduit 34 adapted to put thesuction opening 12 in direct communication with the inlet opening 21 of the pumpingchamber 20. Theauxiliary suction conduit 34 has a substantially rectilinear arrangement and is contained at said upper zone S of theinner cavity 11 of thepump body 10 located above the longitudinal axis A. In particular, theauxiliary suction conduit 34 is inclined at an angle of predetermined width with respect to the longitudinal axis A; this angle is included for example in a range around 45°, depending on the size of the pump. - In practice, the
auxiliary suction conduit 34 has a slightly curved portion at its top, which is inserted into the top of the feedingconduit 33 in front of thesuction opening 12. Preferably, the upper portion of theauxiliary suction conduit 34 engages in the top of the feedingconduit 33 with its axis substantially parallel to the horizontal axis of thesuction opening 12. - A
non-return valve 35 is arranged inside theauxiliary suction conduit 34, in a substantially central position. Thenon-return valve 35 is adapted to close theauxiliary suction conduit 34 when the pressure at the area of the collectingsuction conduit 32 near the mouth of the inlet opening 21 of the pumpingchamber 20 is higher than the pressure at the top of theauxiliary suction conduit 34. - The operation of the self-priming centrifugal pump may be easily understood from the above description.
- In use, the total flow rate passing through the
impeller group 22 is introduced into theinner cavity 11 of thepump body 10. This total flow is partly delivered through theoutlet opening 14 and partly drawn back into circulation through theejection nozzle 31, thanks to the Venturi effect, which is produced in the collectingsuction conduit 32. - When the required flow rate exceeds a predetermined value, the
non-return valve 35 opens theauxiliary suction conduit 34 and allows the liquid to pass directly from thesuction opening 12 to the inlet of the pumpingchamber 20. In this way cavitation phenomena are avoided in the area surrounding the ejection nozzle, at the inlet of the collectingsuction conduit 32, while allowing the overall flow entering theimpeller group 22 to increase up to the desired value. - In particular, when working with high flow rates, the pressure at the area of the collecting
suction conduit 32 near the mouth of the inlet opening 21 of the pumpingchamber 20 is lower than the pressure at the top of theauxiliary suction conduit 34 and therefore thenon-return valve 35 opens theauxiliary suction conduit 34. In this way, a greater flow rate and greater efficiency are obtained than with a traditional self-priming pump. - Conversely, when working with low flow rates, the pressure at the area of the collecting
suction conduit 32 near the mouth of the inlet opening 21 of the pumpingchamber 20 is higher than the pressure at the top of theauxiliary suction conduit 34 and therefore thenon-return valve 35 closes theauxiliary suction conduit 34. In this way, a greater prevalence is obtained compared to a traditional centrifugal pump. - In practice, it has been found that the self-priming centrifugal pump according to the present invention has a trend of the head and of the efficiency which maintain relatively high values for flows significantly higher than the traditional pumps, as shown in the graphs of
Figures 2 and 3 where it is indicated with the continuous lines h and p the variation respectively of the head and the percentage efficiency of the pump in question according to the flow rate, compared to that of a traditional pump represented with the dotted lines H and P. It should be noted that the head and efficiency of the pump according to the present invention maintain a satisfactory value even when the Q' value, which represents the maximum flow rate achievable in the centrifugal pumps of the traditional type, is exceeded. - The self-priming centrifugal pump according to the present invention thus reaches the purpose of increasing the maximum flow rate achievable while maintaining high levels of performance.
- In the practical embodiment of the invention, the used materials, as well as the shape and the dimensions, may vary depending on requirements.
Claims (6)
- Self-priming centrifugal pump, comprisinga pump body (10) provided with an inner cavity (11) having a longitudinal axis (A) arranged in use in a horizontal position, said axis defining into said inner cavity (11) an upper zone (S) and a lower zone (I);a suction opening (12) made on a frontal surface (13) of said pump body (10) at said upper zone (S), located above said longitudinal axis (A);an outlet opening (14) made on an upper surface (15) of said pump body (10);a pumping chamber (20) associated with said pump body (10) and having at a frontal part thereof an axial inlet opening (21);an impeller group (22) arranged into said pumping chamber (20) and provided with an axial hub (23) configured to be associated with a motor shaft (24) coaxial thereto, according to said longitudinal axis (A);an ejector group (30) which is located into said inner cavity (11) of the pump body (10) and which is axially associated with said pumping chamber (20), said ejector group (30) comprising an ejection nozzle (31) and a collecting suction conduit (32) shaping a diverging profile, connected, at the end of the wider section thereof, to said inlet opening (21) of the pumping chamber (20),a feeding conduit (33) configured for connecting said suction opening (12) with said collecting suction conduit (32), at said ejection nozzle (31),an auxiliary suction conduit (34) arranged into said inner cavity (11) of the pump body (10), at said upper zone (S) located above said horizontal axis (A), and configured for directly connecting said suction opening (12) with said inlet opening (21) of the pumping chamber (20),characterized in that it comprises a non-return valve (35) arranged inside said auxiliary suction conduit (34) for blocking the same auxiliary suction conduit (34) when the pressure at the zone of the collecting suction conduit (32) close to the mouth of said inlet opening (21) of the pumping chamber (20) is higher than the pressure at the upper part of the auxiliary suction conduit (34).
- Centrifugal pump according to claim 1, characterized in that said auxiliary suction conduit (34) has a substantially rectilinear shape.
- Centrifugal pump according to claim 2, characterized in that said auxiliary suction conduit (34) is inclined according to an angle with respect to said longitudinal axis (A).
- Centrifugal pump according to any of the preceding claims, characterized in that said feeding conduit (33) is directed in a substantially radial direction with respect to said collecting suction conduit (32) at said upper zone (S) of the pump body (10) and at the upper part is connected with said suction opening (12)
- Centrifugal pump according to any of the preceding claims, characterized in that at a high flow rate the pressure at the zone of the collecting suction conduit (32) close to the mouth of said inlet opening (21) of the pumping chamber (20) is lower than the pressure at the upper part of the auxiliary suction conduit (34), so that said non-return valve (35) opens said auxiliary suction conduit (34).
- Centrifugal pump according to any of the preceding claims, characterized in that at a low flow rate the pressure at the zone of the collecting suction conduit (32) close to the mouth of said inlet opening (21) of the pumping chamber (20) is higher than the pressure at the upper part of the auxiliary suction conduit (34), so that said non-return valve (35) blocks said auxiliary suction conduit (34).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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IT201800008547 | 2018-09-12 | ||
PCT/IT2019/050168 WO2020053906A1 (en) | 2018-09-12 | 2019-07-18 | Self-priming centrifugal pump |
Publications (2)
Publication Number | Publication Date |
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EP3850219A1 EP3850219A1 (en) | 2021-07-21 |
EP3850219B1 true EP3850219B1 (en) | 2022-09-07 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP19765816.4A Active EP3850219B1 (en) | 2018-09-12 | 2019-07-18 | Self-priming centrifugal pump |
Country Status (6)
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EP (1) | EP3850219B1 (en) |
CN (1) | CN112703320B (en) |
EC (1) | ECSP21021418A (en) |
MX (1) | MX2021003000A (en) |
PH (1) | PH12021550536A1 (en) |
WO (1) | WO2020053906A1 (en) |
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CN113586458B (en) * | 2021-08-30 | 2023-06-09 | 陈荣国 | Self-priming multi-stage composite shielding pump |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB397035A (en) * | 1933-02-24 | 1933-08-17 | Holden & Brooke Ltd | Improvements in or relating to means for priming centrifugal pumps |
US2634680A (en) * | 1949-10-17 | 1953-04-14 | Schleyer Victor | Pump |
IT1225596B (en) * | 1988-09-26 | 1990-11-22 | Calpeda A Spa | SELF-PRIMING EJECTOR PUMP. |
DE9314532U1 (en) * | 1993-09-25 | 1993-12-09 | Stuebbe Asv Gmbh | Self-priming centrifugal pump |
NL1019411C2 (en) * | 2001-11-22 | 2003-05-27 | Nicolaas Pieter Verspaget | Self-suction centrifugal pump has housing of which inner part is formed by pressure chamber and flexible suction hose is connected to housing suction connection |
RU2351805C1 (en) * | 2007-12-12 | 2009-04-10 | Закрытое акционерное общество "Гидрогаз" | Self-priming centrifugal pump |
CN102562604A (en) * | 2011-12-22 | 2012-07-11 | 安徽江南泵阀有限公司 | High-performance strong-corrosion-resistant self-sucking pump |
CN105298857B (en) * | 2015-11-19 | 2017-12-05 | 江苏大学 | A kind of non-return valve of big-flow self-priming centrifugal pump self-suction system |
CN205977708U (en) * | 2016-08-29 | 2017-02-22 | 浙江人民泵业有限公司 | Injection formula is from inhaling charge pump |
-
2019
- 2019-07-18 CN CN201980059728.2A patent/CN112703320B/en active Active
- 2019-07-18 WO PCT/IT2019/050168 patent/WO2020053906A1/en unknown
- 2019-07-18 MX MX2021003000A patent/MX2021003000A/en unknown
- 2019-07-18 EP EP19765816.4A patent/EP3850219B1/en active Active
-
2021
- 2021-03-11 PH PH12021550536A patent/PH12021550536A1/en unknown
- 2021-03-26 EC ECSENADI202121418A patent/ECSP21021418A/en unknown
Also Published As
Publication number | Publication date |
---|---|
CN112703320A (en) | 2021-04-23 |
ECSP21021418A (en) | 2021-07-30 |
EP3850219A1 (en) | 2021-07-21 |
PH12021550536A1 (en) | 2022-02-14 |
MX2021003000A (en) | 2021-05-27 |
WO2020053906A1 (en) | 2020-03-19 |
CN112703320B (en) | 2023-02-28 |
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