WO2018167542A1

WO2018167542A1 - Air-liquid separator for centrifugal pumps and pump system comprising such separator

Info

Publication number: WO2018167542A1
Application number: PCT/IB2017/051568
Authority: WO
Inventors: Antonio TITOMANLIO
Original assignee: Varisco S.P.A.
Priority date: 2017-03-17
Filing date: 2017-03-17
Publication date: 2018-09-20

Abstract

An air-liquid separator (1) for centrifugal pumps, which comprises a hollow body (9) defining an air-liquid separation chamber (10) and having a lower portion (11) with a through hole (12) for the passage of a liquid (L) containing air (A) and an upper portion (13) with a suction port (14) for sucking in air (A), a connection conduit (15) for connecting the through hole (12) to a centrifugal pump (3) at the lower portion (11) for introducing the liquid (L), a cover (16) placed on top of the port (14) and having a connector (17) for an air suction line (5) and valve means (22) for selectively occluding the port (14) to regulate the flow of air (A) from the separation chamber (10) to the suction line (5). The valve means (22) are accommodated in the separation chamber (10) and comprise a lower floating member (23) which is adapted to interact with an upper valve member (24) designed to selectively occluding the port (14). A pump system (2) comprising an air-liquid separator as defined above, which is connected to a centrifugal pump (3) and to an air suction line (5).

Description

AIR-LIQUID SEPARATOR FOR CENTRIFUGAL PUMPS AND PUMP SYSTEM COMPRISING SUCH SEPARATOR

Field of the invention

[0001 ] The present invention generally finds application in the field of fluid machines and particularly relates to an air-liquid separator for non-self- priming centrifugal pumps.

[0002] The invention also relates to a pump system comprising such air-liquid separator.

Background art

[0003] Pumping systems has been long known to be used in the field of fluid machines, and are configured to pump up clean water, water with solid suspensions, bentonite or seawater operating overhead, i.e. at a higher level as compared with the liquid to be pumped.

[0004] A typical drawback o these pumping systems is that no exact check of what is sucked in by the pumps through the conduits is allowed.

[0005] Therefore some of the conduits may suck in the liquid, others may suck in a liquid mixed with air and others may suck air only.

[0006] This drawback is particularly felt in case of non-self-priming pumps, which cannot start up with air or gas within the pump body.

[0007] In an attempt to at least partially obviate these drawbacks, separators have been developed which can separate air from the liquid and discharge air outside to cause pump priming.

[0008] VI2014A0001 59, by the applicant thereof, discloses a separator comprising a separation chamber connected to the pump through a hole for the passage of a liquid, a discharge line for discharging air connected to a suction line and valve means for controlling the air flow to the discharge line.

[0009] The separation chamber accommodates a float and the valve means comprise a pair of spherical members which are operably associated with the float via a rigid stem and are held within a hollow body separated from the separation chamber.

[001 0] As liquid flows into the separation chamber, it lifts the float and displaces the spherical members in the hollow body to cause air to flow out of the separation chamber and into the discharge line.

[001 1 ] Air or gas is later conveyed outside from the suction line connected to the discharge line.

[001 2] A first drawback of this arrangement is that valve means are poorly responsive when regulating air discharge with respect to the introduction of liquid.

[001 3] This drawback is one of the causes for a long and complex priming procedure of the centrifugal pump.

[0014] A further drawback is that these separators include a great number of parts and are very complex.

[001 5] This drawback is one of the causes for the complexity of installation and maintenance of the separator by an operator.

[001 6] Another drawback is that the parts that connect the float with the valve means, e.g. the stem, are prone to early wear, particularly with dirty waters or waters with suspended solids, and require periodic maintenance.

[001 7] A further drawback is that these separators have a very large bulk and cannot be properly installed and connected to the pumps.

Technical Problem

[001 8] In view of the prior art, the technical problem addressed by the present invention consists in providing an air-liquid separator for centrifugal pumps that is highly responsive in air discharge operations and affords quick and efficient pump priming.

Disclosure of the invention

[001 9] The object of the present invention is to obviate the above drawback, by providing an air-liquid separator that is highly efficient and relatively cost- effective.

[0020] A particular object of the present invention is to provide an air-liquid separator of the aforementioned type that can quickly discharge air upon introduction of liquid into the separation chamber.

[0021 ] Another object of the present invention is to provide a separator of the aforementioned type, that can cause quick ad efficient priming of the centrifugal pump. [0022] Yet another object of the present invention is to provide a separator of the aforementioned type that has a small number of parts.

[0023] Another object of the present invention is to provide a separator of the aforementioned type that has low maintenance requirements.

[0024] A further object of the present invention is to provide a separator of the aforementioned type that has very small dimensions.

[0025] Yet another object of the present invention is to provide a separator of the aforementioned type that comprises parts with a very long half-life, that can be easily replaced when needed.

[0026] These and other objects, as better explained below, are fulfilled by an air-liquid separator for centrifugal pumps as defined in claim 1 , which comprises a hollow body defining an air-liquid separation chamber and having a lower portion with a through hole for the passage of a liquid containing air and an upper portion with a suction port for sucking in air, a connection conduit for connecting the through hole to a centrifugal pump at the lower portion for introducing the liquid, a cover placed on top of the port and having a connector for an air suction line and valve means for selectively occluding the port to regulate the flow of air from the separation chamber to the suction line.

[0027] The valve means are accommodated in the separation chamber and comprise a lower floating member which is adapted to interact with an upper valve member adapted to selectively occlude the port.

[0028] In a further aspect, the invention relates to a pumping system comprising the aforementioned separator, as defined in claim 1 0.

[0029] Advantageous embodiments of the invention are obtained in accordance with the dependent claims.

Brief description of the drawings

[0030] Further features and advantages of the invention will be more apparent from the detailed description of a preferred, non-exclusive embodiment of an air-liquid separator for centrifugal pumps and a pump system according to the invention, which is described as a non-limiting example with the help of the annexed drawings, in which: FIG. 1 is a perspective view of a pumping system comprising the separator of the invention;

FIGS. 2 and 3 are perspective and side views of the separator of the invention;

FIGS. 4 and 5 are broken away and perspective top and side views of a second detail of the separator of Fig. 3;

FIG. 6 is a broken away top and side view of a third detail of the separator of Fig. 3;

FIGS. 7 to 9 are broken away side views of the separator in different operating configurations.

Detailed description of a preferred exemplary embodiment

[0031 ] Particularly referring to the aforementioned figures, there is shown an air-liquid separator, generally designated by numeral 1 , within a pump system 2.

[0032] As shown in FIG. 1 , the pumping system 2 includes a centrifugal pump 3 of the non-self-priming type for lifting a liquid L containing air A, separation means 4 for separating air A from the liquid L, which comprise the aforementioned separator 1 and are in fluid communication with the pump 3, and a suction line 5 for sucking in air A connected to the separator 1 .

[0033] The pump 3 is configured to operate overhead, i.e. above the level of the liquid to be pumped, and comprises a feed conduit 6 connected to a suction pipe for sucking in liquid L, not shown, and along which the separator 1 is placed.

[0034] Furthermore, the centrifugal pump 3 comprises an outlet conduit 7 for the liquid L, which is connected to a delivery pipe for the liquid L, also not shown.

[0035] The suction line 5 may comprise either a vacuum pump 8 or a Venturi system previously connected to a compressor.

[0036] Preferably, the separator 1 may be used in pump system for separating air A from clean waters, waters with suspended solids, bentonite and seawater.

[0037] In a preferred embodiment of the invention, the separator 1 comprises a hollow body 9 which defines an air-liquid separation chamber 10. Furthermore, the body 9 comprises a lower portion 1 1 with a through hole 12 for the passage of a liquid L containing air A and an upper portion 1 3 with an air suction port 14.

[0038] The separation chamber 1 0 may be accessed from the outside for maintenance through an opening 9' formed in the wall 9" of the body 9 and may be closed by a removable door 9"', as shown in FIG. 2.

[0039] A connection conduit 1 5 is provided for connecting the through hole 1 2 to a centrifugal pump 3 as discussed above at the lower portion 1 1 of the body 9 to allow liquid L to flow into the separation chamber 10.

[0040] Advantageously, the body 9 may define a substantially vertical extension axis Y whereas the connection conduit 1 5 may define a substantially horizontal extension axis X.

[0041 ] In one embodiment that is not shown, the connection conduit 1 5 may be connected to the hollow body 9 via a plurality of vertically offset radial flanges.

[0042] The separator 1 comprises a cover 1 6, as best shown in FIG. 6, placed on top of the port 14 and having a connector 17 for coupling it with the air suction line 5.

[0043] The cover 1 6 may comprise a substantially radial flange 1 8 which is adapted to be connected to the upper portion 1 3 of the body 9 at a partition or a plate 1 9 via a plurality of anchor screws, not shown, introduced into respective holes 20.

[0044] The partition 1 9 is substantially perpendicular to the vertical axis Y and has the air suction port 14 formed therein. Furthermore, the cover 1 6 comprises one or more baffles 21 defining a labyrinth path to prevent the passage of the liquid K in the chamber 1 0 from the port 14 to the connector 1 7.

[0045] Valve means 22 are further provided, which are adapted to occlude the port 14 for regulating the passage of air A from the separation chamber 1 0 to the suction line 5.

[0046] In a peculiar aspect of the invention, the valve means 22 are accommodated in the separation chamber 10 and comprise a lower floating member 23 which is adapted to interact with an upper member 24 designed to selectively occlude the port 14.

[0047] Therefore, the valve means 22 are adapted to be moved within the separation chamber 10 directly from the liquid L flowing therein to regulate the discharge of air A.

[0048] This configuration imparts higher responsiveness and speed to the separator 1 for discharge of air A from the separation chamber 1 0 as compared with the moment in which the liquid L flows therein, thereby increasing the priming speed of the pump 3.

[0049] Furthermore, the separator 1 of the invention has a smaller number of parts and can be easily assembled and accessed during maintenance by an operator.

[0050] Advantageously, the lower valve member 23 may have a smaller weight than the upper valve member 24, such that it may be lifted and float in the liquid L that flows into the separation chamber 1 0.

[0051 ] For this purpose, the upper valve member 24 may be entirely made of rubber, whereas the lower valve element 23 may have a nylon core, which is lighter than rubber, and is covered with a rubber layer, as shown in FIGS. 7 to 9.

[0052] Of course, the valve means 22 may be made from suitable materials other than those as mentioned above, as long as the upper valve member 24 is heavier than the lower member 23 and the latter acts as a float in the liquid L.

[0053] As shown in the figures, the upper valve member 24 and the lower valve member 23 have a substantially spherical shape with respective diameters d1 , d2 and arranged one on top of the other.

[0054] Preferably, the spherical valve member 23, 24 have the same size, i.e. substantially the same diameter. In one embodiment, not shown, both valve members 23, 24 may be formed of the same material, and have different sizes, for the upper member 24 to be heavier than the lower member 23.

[0055] As mentioned above, the valve means 22 are accommodated in the separation chamber 1 0. For this purpose, the body 9 may have a first substantially annular support 25 therein, proximate to its lower portion 1 1 , as shown in FIG. 4, for supporting the lower valve member 23.

[0056] Furthermore, the body 9 comprises a second substantially annular support 26 therein, at its upper portion 1 3, for supporting the upper valve member 24.

[0057] The two respective supports 25, 26 are rigidly joined to the inner wall 27 of the separation chamber 1 0 and allow the valve member 23, 24 to be maintained in an initial lowered position in which they are at a predetermined axial distance s from each other, as best shown in FIG. 7.

[0058] The supports 25, 26 may also have a shape slightly differing from the annular shape of the figures, without departure from the scope of the present invention.

[0059] The first support 25 may comprise a funnel-shaped flange 28 with an open lower edge 29 defining the through hole 1 2 with a diameter D, smaller than the diameter d2 of the lower valve member 23, such that the latter will block it when it is in the initial position.

[0060] In operation, as the liquid L rises in the separation chamber 1 0, the lower valve member 23 will be lifted upwards by buoyancy until it reaches an intermediate position, as best shown in FIG. 8.

[0061 ] In this intermediate position, the lower valve member 23 contacts the upper valve member 24 and air A is progressively sucked in through the port 14 which is kept open.

[0062] The second support 26, as shown in FIG. 5, comprises a plurality of radial appendages 30, which are adapted to retain the upper valve member

24 at the distance s from the lower valve member 23.

[0063] On the other hand, the second support 26 allows the passage of air A as the latter is being sucked in, and allows the lower valve member 23 to interact with the upper member 24 in the intermediate position.

[0064] In the embodiment as shown in the figures, the second support 26 comprises four angularly arranged radial appendages 30. Nevertheless, a different number of appendages 30 may be also envisaged, without departure from the scope of the present invention.

[0065] In the initial position, the lower valve member 23 may be subjected to small axial displacements to allow the passage of air A which is progressively sucked in by the suction line 5.

[0066] Then, the lower valve member 23 is further lifted from the liquid L that flows into the separation chamber 1 0 to move the upper valve member 24 to a final position in which the port 14 is blocked, as shown in FIG. 9.

[0067] In this final position, the air A has been entirely sucked off the separation chamber 10, and the liquid L entirely fills it without coming out of the port 14, which is blocked by the upper valve member 24.

[0068] The level of the liquid L in the separation chamber 1 0 may be exposed to cyclic changes caused by the suction effect of the suction line 5.

[0069] These changes cause a temporary detachment of the upper valve member 24 from the port 14, to ensure reversible operation of the separator 1 .

[0070] Therefore, the weight of the upper valve member 24 shall be selected to ensure temporary detachment from the port 14 even when the suction line 5 continues to operate.

[0071 ] The above disclosure clearly shows that air-liquid separator and the pumping system fulfill the intended objects, and particularly allow such distance to be adjusted in a simple and consistent manner.

[0072] The separator and pumping system of the invention are susceptible to a number of changes or variants, within the inventive concept disclosed in the appended claims.

[0073] While the separator and pumping system have been described with particular reference to the accompanying figures, the numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.

Industrial Applicability

[0074] The present invention may find application in industry, because it can be produced on an industrial scale in fluid machine manufacturing plants.

Claims

1 . An air-liquid separator (1 ) for centrifugal pumps, comprising:

- a hollow body (9) which defines an air-liquid separation chamber (1 0), said body (9) having a lower portion (1 1 ) with a through hole (1 2) for the passage of a liquid (L) containing air (A) and an upper portion (1 3) with a suction port (14) for sucking air (A);

- a connection conduit (1 5) for connecting said through hole (12) to a centrifugal pump (3) at the lower portion (1 1 ) of said body (9) for introducing the liquid (L);

- a cover (1 6) placed on top of said port (14) and having a connector

(1 7) for coupling it to an air suction line (5);

- valve means (22) for selectively occluding said port (14) to regulate the flow of air (A) from said separation chamber (1 0) to said suction line (5); characterized in that said valve means (22) are accommodated in said separation chamber (1 0) and comprise a floating lower valve member (23) which is adapted to interact with an upper valve member (24) adapted to selectively occluding said port (14).

2. A separator as claimed in claim 1 , characterized in that said lower member (23) has a lower weight than said upper member (24).

3. A separator as claimed in claim 2, characterized in that said lower member (23) and said upper member (24) both have a substantially spherical shape and are placed one on top of the other.

4. A separator as claimed in claim 2, characterized in that said upper valve member (24) is entirely made of rubber and said lower valve member (23) comprises a nylon core covered with rubber.

5. A separator as claimed in claim 1 , characterized in that said body (9) comprises internally thereof a first substantially annular support (25) proximate to its lower portion (1 1 ) said support (25) being adapted to support said lower valve member (23) in an initial lowered position in which said valve members (23, 24) are in spaced relationship.

6. A separator as claimed in claim 5, characterized in that said first support (25) comprises a substantially funnel-shaped flange (28) with a lower edge (29) defining said through hole (1 2), said lower valve member

(23) being adapted to block said hole (1 2) in said initial position and to be lifted from the liquid (L) that flows in from said conduit (15) to an intermediate position in which it contacts said upper valve member (24) while progressively sucking in the air (A) contained in the liquid (L).

7. A separator as claimed in claim 6, characterized in that said body (9) comprises therein a second substantially annular support (26), proximate to its upper portion (1 3), for supporting said upper valve member

(24) in said initial position, and for allowing said lower valve member (23) to interact with said upper valve member (24) to move it to a final lifted position according said port (14), to prevent liquid (L) from flowing out of it once air (A) has been entirely sucked in from said chamber (1 0).

8. A separator as claimed in claim 7, characterized in that said second support (26) comprises a plurality of radial appendages (30) for retaining said upper valve member (24) at a predetermined radial distance (s) from said lower spherical member (23) when this latter is in its initial position.

9. A separator as claimed in claim 1 , characterized in that said cover (1 6) is joined to said upper portion of said body (2) by a partition (1 9) with said port (14) formed therein and has one or more baffles (21 ) which define a labyrinth path to prevent the passage of the liquid (L) from said port (14) to said connector (1 7).

1 0. A pump system (2) comprising a centrifugal pump (3) with a feed conduit (6) connected to a suction pipe for sucking in liquid (L), separation means (4) for separating the air (A) in the liquid (L) placed at the feed conduit (6) and a suction line (5) for sucking in the air (A) separated from the liquid (L), connected to said separation means (4), characterized in that said separation means (4) comprise a separator (1 ) as claimed in one or more of claims 1 to 9.