EP3850219A1 - Self-priming centrifugal pump - Google Patents

Self-priming centrifugal pump

Info

Publication number
EP3850219A1
EP3850219A1 EP19765816.4A EP19765816A EP3850219A1 EP 3850219 A1 EP3850219 A1 EP 3850219A1 EP 19765816 A EP19765816 A EP 19765816A EP 3850219 A1 EP3850219 A1 EP 3850219A1
Authority
EP
European Patent Office
Prior art keywords
suction conduit
pumping chamber
pump body
conduit
opening
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.)
Granted
Application number
EP19765816.4A
Other languages
German (de)
French (fr)
Other versions
EP3850219B1 (en
Inventor
Luca NICOLIN
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pedrollo SpA
Original Assignee
Pedrollo SpA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Pedrollo SpA filed Critical Pedrollo SpA
Publication of EP3850219A1 publication Critical patent/EP3850219A1/en
Application granted granted Critical
Publication of EP3850219B1 publication Critical patent/EP3850219B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • 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.
  • FIGS 2 and 3 illustrate in graphical form, with the dotted lines FI 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 of predetermined width with respect to said longitudinal axis of the pump body.
  • said angle of predetermined width 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.
  • Figures 2 and 3 show a graph respectively of the head and the efficiency of the pump as a function of the flow rate.
  • 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 1 1.
  • 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 1 1 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 1 1 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 1 1 of the pump body 10.
  • the pumping chamber 20 substantially closes the inner cavity 1 1 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 1 1 of the pump body 10.
  • the ejector group 30 comprises an ejection nozzle
  • 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
  • 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 1 1 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
  • 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
  • the total flow rate passing through the impeller group 22 is introduced into the inner cavity 1 1 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 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 self-priming centrifugal pump described by way of example may change according to the different requirements.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Abstract

The self-priming centrifugal pump comprises a pump body (10) having an inner cavity (11 ) having a longitudinal axis (A) arranged in a horizontal position in use configuration which divides said inner cavity (11) into an upper zone (S) and a lower zone (I); a suction opening (12) made on a front surface (13) of said pump body (10) at said upper zone (S); 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 inside said pumping chamber (20); an ejector group (30) which extends into said inner cavity (11) of the pump body (10) and comprises an ejection nozzle (31) and an suction conduit (32) shaping a divergent profile, connected, at the wider section thereof to the inlet opening (21) of the pumping chamber (20); an auxiliary suction conduit (34) arranged inside said inner cavity (11 ) of the pump body (10), at said upper zone (S), and adapted to put said suction opening (12) in direct communication with said inlet opening (21) of the pumping chamber (20).

Description

Description
SELF-PRIMING CENTRIFUGAL PUMP
Technical field
[01] The present invention relates to a self-priming centrifugal pump.
Prior art
[02] 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.
[03] 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.
[04] 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.
[05] 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.
[06] Patent EP 0.401.670 illustrates, for example, a self-priming centrifugal pump of this type.
[07] 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.
[08] Figures 2 and 3 illustrate in graphical form, with the dotted lines FI 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.
[09] 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.
[10] GB 397,035 discloses a further embodiment of a self-priming centrifugal pump equipped with a by-pass conduit.
[1 1 ] However, these solutions are not exempt from improvements.
Disclosure
[12] 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.
[13] 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.
[14] Another object of the invention is to provide a self-priming centrifugal pump which allows the efficiency of the pumping group to be improved.
[15] 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.
[16] The aforementioned objects are achieved, according to the present invention, by the self priming centrifugal pump according to claim 1 .
[17] 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.
[18] 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.
[19] 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.
[20] 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. [21] Preferably, said auxiliary suction conduit opens into the upper part of said first portion at a constant inclination of the collecting suction conduit.
[22] Advantageously, the pump comprises a non-return valve arranged inside said auxiliary suction conduit.
[23] Advantageously, said auxiliary suction conduit has a substantially rectilinear arrangement.
[24] Preferably, said auxiliary suction conduit is inclined at an angle of predetermined width with respect to said longitudinal axis of the pump body.
[25] Preferably, said angle of predetermined width is approximately 45°.
[26] 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.
[27] 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.
[28] 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.
[29] Preferably, said feeding conduit opens into a portion of said collecting suction conduit arranged in a toroidal shape around said ejection nozzle.
[30] 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.
[31] In this way, the non-return valve opens the said auxiliary suction conduit, allowing the pump to achieve a high flow rate and efficiency.
[32] 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.
[33] In this way, the non-return valve closes the said auxiliary suction duct, allowing the pump to maintain a high head.
Description of drawings
[34] 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.
Embodiments of the invention
[35] 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 an inner cavity 1 1. The pump body 10 defines the casing of the operating members of the pump.
[36] 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.
[37] The longitudinal axis A divides the inner cavity 1 1 of the pump body 10 into an upper zone S and in a lower zone I.
[38] 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.
[39] 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 1 1 of the pump body 10. The outlet opening 14 is arranged radially with respect to the longitudinal axis A of the pump body 10.
[40] 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 1 1 of the pump body 10. The pumping chamber 20 substantially closes the inner cavity 1 1 of the pump body 10 on the opposite side the frontal surface 13.
[41] Inside the pumping chamber 20 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.
[42] An ejector group 30 is axially associated with the pumping chamber 20 and extends inside the inner cavity 1 1 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.
[43] Preferably the feeding conduit 33 opens into a portion of collecting suction conduit 32 arranged in a toroidal shape around the ejection nozzle 31 .
[44] In the illustrated embodiment, 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.
[45] According to the present invention, 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 1 1 of the pump body 10 located above the longitudinal axis A. In particular, 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.
[46] In practice, 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. Preferably, 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.
[47] 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.
[48] The operation of the self-priming centrifugal pump may be easily understood from the above description.
[49] In use, the total flow rate passing through the impeller group 22 is introduced into the inner cavity 1 1 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.
[50] When the required flow rate exceeds a predetermined value, 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.
[51] 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 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.
[52] 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 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.
[53] 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.
[54] 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.
[55] The self-priming centrifugal pump described by way of example may change according to the different requirements.
[56] In the practical embodiment of the invention, the used materials, as well as the shape and the dimensions, may vary depending on requirements.
[57] Should the technical features mentioned in any claim be followed by reference signs, such reference signs were included strictly with the aim of enhancing the understanding of the claims and hence they shall not be deemed restrictive in any manner whatsoever on the scope of each element identified for exemplifying purposes by such reference signs.

Claims

Claims
1. Self-priming centrifugal pump, comprising
a pump body (10) provided with an inner cavity (1 1 ) having a longitudinal axis (A) arranged in use in a horizontal position, said axis defining into said inner cavity (1 1 ) 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 (1 1 ) 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 (1 1 ) 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).
2. Centrifugal pump according to claim 1 , characterized in that said auxiliary suction conduit (34) has a substantially rectilinear shape.
3. Centrifugal pump according to claim 2, characterized in that said auxiliary suction conduit (34) is inclined according to an angle of determined width with respect to said longitudinal axis (A).
4. 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)
5. 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).
6. 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).
EP19765816.4A 2018-09-12 2019-07-18 Self-priming centrifugal pump Active EP3850219B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
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
EP3850219A1 true EP3850219A1 (en) 2021-07-21
EP3850219B1 EP3850219B1 (en) 2022-09-07

Family

ID=64607079

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19765816.4A Active EP3850219B1 (en) 2018-09-12 2019-07-18 Self-priming centrifugal pump

Country Status (6)

Country Link
EP (1) EP3850219B1 (en)
CN (1) CN112703320B (en)
EC (1) ECSP21021418A (en)
MX (1) MX2021003000A (en)
PH (1) PH12021550536A1 (en)
WO (1) WO2020053906A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113586458B (en) * 2021-08-30 2023-06-09 陈荣国 Self-priming multi-stage composite shielding pump

Family Cites Families (9)

* Cited by examiner, † Cited by third party
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 ASV Stübbe GmbH & Co KG, 32602 Vlotho 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

Also Published As

Publication number Publication date
CN112703320A (en) 2021-04-23
ECSP21021418A (en) 2021-07-30
PH12021550536A1 (en) 2022-02-14
MX2021003000A (en) 2021-05-27
WO2020053906A1 (en) 2020-03-19
CN112703320B (en) 2023-02-28
EP3850219B1 (en) 2022-09-07

Similar Documents

Publication Publication Date Title
EP0401670B1 (en) Self-priming centrifugal pump
CN100575712C (en) Centrifugal pump and impeller thereof
US20160169230A1 (en) Pump
US10337516B2 (en) Multi-stage, self-priming centrifugal pump assembly
US2553066A (en) Self-priming centrifugal pump
EP3850219B1 (en) Self-priming centrifugal pump
CA3042635A1 (en) Impeller pump
EP0552661B1 (en) Self priming centrifugal pump
CN208858581U (en) A kind of injection self priming pump avoiding cavitation
US5474418A (en) Self-priming centrifugal pump
US5375975A (en) Fuel pump pre-swirl inlet channel
EP0936356B9 (en) Self-priming jet pump with flow control device
US6390783B1 (en) Hydraulic pump having low aeration single return boost reservoir
WO1996024770A1 (en) Fluid pump
KR100319567B1 (en) Columnar flow pump for supplying fuel from the supply tank to the car's internal combustion engine
US2580347A (en) Centrifugal pump
CN207814052U (en) A kind of centrifugal pump inhibiting cavitation
AU2017379190B2 (en) Vortex pump
CN207583633U (en) A kind of centrifugation cernrifugal pump
CN109707669A (en) A kind of double feed inlet, the efficient inlet segment of double helical form
KR101693929B1 (en) A vacuum self-priming pump
US2394931A (en) Centrifugal pump
CN107795492B (en) Centrifugal vortex water pump
SU729381A1 (en) Centrifugal self-suction recirculation-tyre pump
US1439386A (en) Balanced pump casing

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20210412

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTG Intention to grant announced

Effective date: 20220408

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

Ref country code: AT

Ref legal event code: REF

Ref document number: 1517242

Country of ref document: AT

Kind code of ref document: T

Effective date: 20220915

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602019019362

Country of ref document: DE

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG9D

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20220907

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221207

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 1517242

Country of ref document: AT

Kind code of ref document: T

Effective date: 20220907

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221208

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230109

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230107

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602019019362

Country of ref document: DE

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230412

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

26N No opposition filed

Effective date: 20230608

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20230731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230718

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20230718

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230718

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230718

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20220907

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230718

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230718

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20240826

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20240730

Year of fee payment: 6