EP2088326A2

EP2088326A2 - Mixed flow centrifugal volute pump for swimming pools

Info

Publication number: EP2088326A2
Application number: EP09380008A
Authority: EP
Inventors: Marina Soler Alvarez
Original assignee: Bombas PSH SA
Current assignee: DESARROLLOS EMPRESARIALES VALAR, S.L.
Priority date: 2008-02-05
Filing date: 2009-01-26
Publication date: 2009-08-12
Also published as: ES1067274Y; EP2088326A3; ES1067274U

Abstract

The mixed flow volute pump presents the particular feature of its casing comprising two independent parts (1) and (2) obtained by means of plastic injection molding, preferably of polypropylene, said parts (1) and (2) being joined together by means of screws (4). The materialization of the pump casing in plastic provides advantages such as lower manufacturing costs and less weight compared to conventional pump casings made of cast iron. The two parts (1) and (2) have a special shape such that the corresponding Archimedes volute (3) to be found in conventional pump casings of the same type is defined between them both. Established in the said parts (1) and (2) are flanges (5) for joining them together, along with a flange (6) for fixing to the respective motor, and a flange (7) for coupling to the discharge nozzle for the flow, establishing the closure of the volute (3).

Description

OBJECT OF THE INVENTION

As stated in the title of this descriptive specification, the present invention relates to a mixed flow centrifugal volute pump for swimming pools, whose hydraulic body and pre-filter are materialized wholly in plastic, with the consequent advantages of less weight and lower manufacturing costs compared to conventional pump casings.

BACKGROUND OF THE INVENTION

Mixed flow centrifugal volute pump casings used in swimming pools are generally manufactured in steel and bronze, and they have a main hydraulic body in the form of an Archimedes volute and an auxiliary or pre-filter body, with the consequent coupling flanges to the motor and to the corresponding inlet and outlet.
In general, said pump casings are materialized in GG25 gray cast iron and to a lesser extent in RG5 marine bronze, especially recommended for seawater.
These pump casings, particularly those made of gray cast iron, have always had a problem with rusting, above all when the pump is stopped for a length of time and it is wished to start it up again, in which case the initial discharge of fluid is generally rusty.
Moreover, metal pump casings are heavy, which makes them difficult to handle, above all when it comes to their assembly, packaging and transportation.
It can also be highlighted that metal pump casings, particularly bronze ones, have the drawback that micropores frequently appear, with the consequent problem that this entails.
Another drawback of metal pump casings that can likewise be emphasized is that they do not meet the established safety specifications in terms of insulation of the hydraulic part and of the electrical part.
Finally, another important aspect of metal pump casings is the appearance of the phenomenon known as "electrolysis" due to the turbine being made of bronze and the pump casing of gray cast iron, with the consequent eating away of materials.

DESCRIPTION OF THE INVENTION

The pump forming the object of the invention, having the same dimensions as the aforementioned conventional metal pump casings made of iron and bronze, is characterized in that it is materialized in plastic (preferably polypropylene) in such a way that the volute-shaped hydraulic body is made of two independent parts obtained in an injection molding process and joined to each other around their perimeters by screws, with the insertion of a sealing gasket. Each part of said hydraulic body will be obtained in a different mold, in other words, a mold with an appropriate shape for each of the two parts, in which a pre-filter body for the pump itself will also be established. In other words, the complete Archimedes volute is formed in the plastic material hydraulic body.
Likewise formed in one of the parts constituting the pump casing is the securing flange for the motor, there existing a second securing flange in the discharge nozzle for closure of the volute.
From the constitution and characteristics of the said pump casing, a series of advantages is deduced compared to conventional pump casings, the most important of which that can be mentioned being the following:

Lower manufacturing costs.
Same features as pump casings made of iron and bronze.
Improvement in hydraulic efficiency compared to conventional pump casings.
Equal dimensioning as FD series pump casings, both in bronze and in iron, which means that the body of the pump casing can be changed without changing the installation.
Possibility of complete insulation of the electrical part with regard to the hydraulic part.
Suitable for seawater.
Less weight than conventional pump casings, with the consequent saving in transportation and greater ease in handling the actual pump.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to complement the description that is going to be made forthwith, and with the aim of aiding a better understanding of the characteristics of the invention, the present descriptive specification is accompanied by a set of drawings on the basis of which the innovations and advantages of the centrifugal pump forming the object of the invention will be more easily understood.

Figure 1.- Shows a view in exploded general perspective of the two parts constituting the pump casing of the invention, along with the screws for fastening the two parts together and the intermediate sealing gasket.
Figure 2.- Shows an upper plan view of the pump casing constituted by means of the union or fastening together of the two parts represented in the previous figure.

PREFERRED EMBODIMENT OF THE INVENTION

As can be seen in the said figures, the pump casing of the invention, produced in plastic and obtained in an injection molding process, is constituted by means of the joining together of two parts 1 and 2, between which a complete Archimedes volute 3 is created, with the particular feature that those two parts 1 and 2 are joined by means of a set of screws 4 passing through holes made for the purpose in the respective plates or wings for the joining of the two parts 1 and 2.
The part 2 also has a flange 6 for coupling of the corresponding motor, while a second flange 7 is provided for its securing in the impulsion mouth as a closure element for the volute 3.
Inserted in the union between the parts 1 and 2 is a sealing gasket 8 which is positioned on annular projections 9 formed for the purpose in the facing surfaces of the parts 1 and 2 which constitute the actual centrifugal pump casing.

Claims

MIXED FLOW VOLUTE CENTRIFUGAL PUMP FOR SWIMMING POOLS comprising a casing which incorporates an hydraulic body with the shape of an Archimedes volute ; characterized in that the casing comprises two independent parts (1 and 2) obtained by means of injection molding, made of a plastic material, fixed to each other around their perimeters by screws (4) and with an intermediate sealing gasket (8).
MIXED FLOW CENTRIFUGAL PUMP FOR SWIMMING POOLS, according to claim 1, characterized in that the two parts (1 and 2), obtained in different and independent molds, have a complementary configuration in order between them to form the complete volute (3) of the hydraulic body of the casing.
MIXED FLOW VOLUTE CENTRIFUGAL PUMP FOR SWIMMING POOLS, according to claim 1, characterized in that the plastic material constituting the two parts (1 and 2) is preferably polypropylene.
MIXED FLOW VOLUTE CENTRIFUGAL PUMP FOR SWIMMING POOLS, according to the above claims, characterized in that one of said parts (2) includes a flange (6) for mounting of the corresponding motor.
MIXED FLOW VOLUTE CENTRIFUGAL PUMP FOR SWIMMING POOLS, according to the above claims, characterized in it includes a flange (7) for securing in the discharge nozzle, establishing the closure of the volute (3).