EP2455616A2

EP2455616A2 - Mixed flow centrifugal pump for swimming pools

Info

Publication number: EP2455616A2
Application number: EP11380090A
Authority: EP
Inventors: Marina Soler Álvarez
Original assignee: DESARROLLOS EMPRESARIALES VALAR SL
Current assignee: DESARROLLOS EMPRESARIALES VALAR SL
Priority date: 2010-11-23
Filing date: 2011-11-08
Publication date: 2012-05-23
Also published as: ES1073978U; EP2455616A3; ES1073978Y

Abstract

The present invention relates to a mixed flow centrifugal pump for swimming pools, being of the type made of injected plastic materials, while having a hydraulic body formed by a first part and a second part independent from each other, between which a complete logarithmic volute is defined, the pump also having a fluid inlet suction mouth located on the first part and a discharge mouth as an outlet for that same fluid; characterized in that it comprises an independent flange (9) as a means for fastening an anchor bracket (10) of a motor associated with the pump, said independent flange (9) being fastened at the front on the second part (2) of the hydraulic body (3) of the pump.

Description

OBJECT OF THE INVENTION

The present invention, as expressed in the title of this specification, refers to a mixed flow centrifugal pump for swimming pools being of the type including a hydraulic body formed by two independent pieces or parts made of plastic material, between which a complete logarithmic volute is defined, so that the use of plastic materials such as polypropylene with fiberglass, provides advantages of lower manufacturing cost compared to conventional hydraulic bodies, since no further machining is needed, and also presenting the advantage of preventing corrosion, while the plastic material prevents the conduction of galvanic and electrical streams, also presenting the advantage of a reduced weight.

BACKGROUND OF THE INVENTION

The mixed flow centrifugal pumps having logarithmic volute used in swimming pools, precisely because of the difficult construction of the volute, are made of a molten metal, usually steel and bronze, showing a main hydraulic body shaped as a logarithmic volute.
Generically said pumps are made of gray cast iron and, in a lesser extent due to their high economic costs, of marine cast bronze and stainless cast, the latter two especially recommended for sea water.
In these gray cast iron pumps (because this cast is composed of iron and carbon), there is always the problem of corrosion in the form of iron oxide.
It is also noteworthy that metal pumps, both made of gray cast iron and of cast bronze and stainless cast, have the disadvantage of the frequent occurrence of micropores, making them useless. These micropores are usually located once the cast is machined; adding to the losses of the cast costs the machining costs as well.
Another major problem often generated in these pumps is the appearance of the physical phenomenon so-called "implosion or cavitation" so that these metallic pumps, due to their molecular structure, the metallic pumps are decomposed to a drilling break, while the polypropylene with fiberglass pumps (utility model ES 200800221 owned by the same holder as the invention at hand), since this is an amorphous and plastic material, these are not so affected by this phenomenon of cavitation.
Another phenomenon that is created in metallic pumps, by the effects of the metallic materials, electrical and constructive conductors, is the appearance of the phenomenon so-called "electrolysis", so that this phenomenon is caused by the ion exchange of the metal parts of the pump in contact with a conductive medium such as water, leading to irreparable damages in the pump. This phenomenon is further aggravated by the current trend to disinfect water with salt chlorinators operated by electrolysis. In the case of plastic pumps, this phenomenon does not occur either, because the building material does not conduct electricity.
Metallic pumps, because of their constructive materials, are conductors of electricity, making it impossible to comply with the safety specifications set for class F as for the insulation of the hydraulic part and electrical part.
On the other hand, metallic pumps are heavy elements, making it difficult to handle them, especially when they are assembled, packaged and transported.

DESCRIPTION OF THE INVENTION

In order to achieve the objectives and avoid the drawbacks mentioned in the preceding paragraphs, the invention proposes a mixed flow centrifugal pump for swimming pools that has a hydraulic body defining a logarithmic volute therein, while consisting of a first part and second part independent from each other, nearly symmetrical, obtained in a process of plastic injection molding, while being perimetrically joined together by screws and nuts, with interposition of a seal.
Each of the parts of the hydraulic body is obtained from a different mold, i.e. a mold with the convenient shape for each of the two half volutes defined within such complementary parts. Thus, the hydraulic body made of plastic formed by the two half volutes of the pump is made up by the complete logarithmic volute formed when joining together both parts of the hydraulic body.
The complete logarithmic volute is closed at the side part by using an independent flange, also made of plastic material, such as polypropylene with fiberglass, while it is fastened to the second part of the hydraulic body by screws and sealed with an O-ring seal. This independent flange is also obtained in an injection molding process of plastic material, such independent flange also making up the fastening to the anchor bracket for holding the motor.
In the discharge mouth of the hydraulic body an upper flange is mounted as an element for closing and joining the two parts of the hydraulic body by threading and also sealed by the above described lead perimeter joint.
There is also an anterior flange arranged in correspondence with the fluid inlet or aspiration mouth, said anterior flange being threadably connected to the anterior part of the hydraulic body while being sealed by an O-ring.
Some advantages over conventional pumps are derived from the constitution and characteristics of the pump of the invention, among which the following can be mentioned as the most important:

The hydraulic performance as compared to metal pumps, is improved as the surface of the volute of the hydraulic body through which the water flows is completely smooth.
- Suitable for seawater since its construction material is non-corrosive.
- Lower manufacturing costs.
- Not affected by the phenomenon of implosion or cavitation.
- Free of electrolysis.
- Not being electrically conductive, complying with the regulation regarding electrical insulation between the hydraulic part and the electrical part of e class F pumps.
- Lighter weight than conventional pumps, with the subsequent saving on the transport and easier for handling the pump.
- More and better performance than iron and bronze pumps.

Next, to facilitate a better understanding of this specification and being an integral part thereof, some figures in which the object of the invention has been represented in an illustrative and not limitative manner are attached.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Figure 1 .- Shows an exploded view of the mixed flow centrifugal pump for swimming pools, object of the invention.
Figure 2 .- Shows a view similar to the previous one in which an anchor bracket of a motor for driving the pump of the invention is also included.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Considering the numbering adopted in the figures, the pump of the invention is made of plastic material and obtained in an injection molding process of said plastic material, being formed by the joining together of a first part 1 and a second part 2, both made up the hydraulic body 3 and between which a complete Archimedes volute 4 is defined, with the peculiarity that these two parts 1-2 are joined together by a plurality of nuts 5 and screws 6 passing through facing holes 7 established in respective perimeter wings 8 of those two complementary and independent parts 1-2.
An independent flange 9 for coupling an anchor bracket 10 of a motor 10'is fastened to the second part 2, while an upper flange 11 is provided to be anchored in a discharge mouth 12 as an element for closing the entire Archimedes volute 4 at the top, that discharge mouth 12 being corresponded with the fluid outlet provided by the pump assembly.
In contrast, a fluid inlet suction mouth 13 is included in the first part 1 of the hydraulic body 3 in correspondence with an anterior flange 14 connected by threading, as occurs with the upper flange 11, while the separate flange 6 is fastened to the second part 2 of the hydraulic body 3 by using some front screws 15.
At the joint between the first part 1 and second part 2 a main tight gasket 16 which is positioned on annular protrusions 17 formed for that purpose on the opposite areas of said parts 1-2 making up the hydraulic body 3 of the centrifugal pump itself, is sandwiched therbetween.
The various flanges 7-11-14 are attached to the hydraulic body 3 of the pump with the interposition of respective tight sealed O-rings 18-19-20.
Finally it should be noted that the two parts 1-2 of the hydraulic body 3 of the pump have bottom feet 21 as elements for seating and fastening the pump assembly.

Claims

Mixed flow centrifugal pump for swimming pools, being of the type made of injected plastic materials, while having a hydraulic body formed by a first part and a second part independent from each other, between which a complete logarithmic volute is defined, the pump also having a fluid inlet suction mouth located on the first part, and a discharge mouth as an outlet for that same fluid; characterized in that it comprises an independent flange (9) as a means for fastening an anchor bracket (10) of a motor associated with the pump, said independent flange (9) being fastened at the front on the second part (2) of the hydraulic body (3) of the pump.
Mixed flow centrifugal pump for swimming pools, according to claim 1, characterized in that the independent flange (9) is fastened to the second part (2) of the hydraulic body (3) by using screws (15).