WO2017046743A1

WO2017046743A1 - Two-stage hydrodynamic pump

Info

Publication number: WO2017046743A1
Application number: PCT/IB2016/055512
Authority: WO
Inventors: Branislav KNÍŽAT; Róbert OLŠIAK
Original assignee: Slovenska Technicka Univerzita V Bratislave
Current assignee: Slovenska Technicka Univerzita V Bratislave
Priority date: 2015-09-16
Filing date: 2016-09-15
Publication date: 2017-03-23
Anticipated expiration: 2018-03-16

Abstract

Two-stage pump is composed of the system of the channels (4) of the first stage and the system of the channels (5) of the second stage which are alternately distributed on a single impeller (1). The channels (4) of the first stage have axial suction inlets (6) in the zone of the rotation of the impeller (1) and the channels (5) of the second stage have radial discharge outlets (7) to this spiral (2) for discharge of the liquid. A transferer (3) is placed behind the impeller (1), whereby the axial outlets (8) of the channels (4) of the first stage lead to the inlet of the transferer (3) in the circumferential zone of the impeller (1). The outlet from the transferer (3) leads to the axial inlets (9) of the channels (5) of the second stage in the zone of the axis of the rotation of the impeller (1).

Description

Two-stage hydrodynamic pump

Field of technology

The invention concerns a construction of the two-stage hydrodynamic pump with the centrifugal impeller, mainly for the pumping of the liquids with the low flow and high pressure. The invention belongs to the field of engineering and hydraulic machinery.

Prior state of the art The pumps are machines where the mechanical energy led to the shaft is transformed to the mechanical energy of the liquid. Specific energy is the mechanical energy of the liquid per unit of its mass. In case of hydrodynamic pumps there is a possibility to increase the specific energy based on the work-energy principle. This is why such pumps are in case of need constructed and designed as multi-stage, whereby the total specific energy is a sum of the contributions at individual stages. Current state of the art can be constructionally characterized as a two-stage pump where each stage has a single impeller. The liquid which runs through the impeller of the first stage is led by the transferer to the entry to the impeller of the second stage. A spiral is behind the second stage, which takes the liquid out to the pipe duct. A built- up volume of the pump increase with the increase of the stages of the multi-stage pump; its weight as well as demands on its maintenance increase, too.

Such arrangements are know, for example, according to publications CN2718290, DE102009013156A1 , JPS5496801A, US4893986A, US2008273990A1 , where two impellers are used, which sets the limits for the diminution of the dimensions and weight of a pump. In order to decrease the pump's weight and the built-up volume, a possibility arose to solve such issues by the technical means capable of addressing these issues. Following construction of the two-stage pump according to this invention is a result of an effort to solve these issues. Essence of the invention

Abovementioned deficiencies are significantly remedied by a construction of the two-stage pump with the centrifugal impeller according to this invention. The essence of the construction of the pump lies in the fact that both stages of the pump are arranged on a single impeller, where there are channels of the first stage and channels of the second stage alternately distributed on a single plane. The pump involves a system of the channels of the first stage and a system of the channels of the second stage, whereby the channels are alternately arranged in one and the same impeller. This means that the impeller contains the channels of the first stage as well as channels of the second stage; together it contains even number of channels.

The impeller has an even number of channels. The channels are distributed in a single plane (perpendicular axis of the rotation) and they are distributed alternately. If the impeller has, for example, 10 channels, then there are five first-stage (1 °) channels and five second-stage (2°) channels. Their arrangement on the impeller is: Ί o 2° Ί ° 2° 1 ° 2° 1 ° 2° 1 ° 2°

The channels of the first and second stage can be variously shaped; they can have simple cylindrical shape or - preferably - they can be radial, which is not a necessary condition, though. The channels of the first and second stage are connected in such a way that half of them operate in the first stage and half of them operate in the second stage. This is not an obstacle, though; on the contrary, the proposed solution broadens the use of the hydrodynamic pumps, since it is not a problem to achieve low specific rotation (that means low flow during high pressure). The complex shape of the channels of the impeller in this type of pumps has no effect - or no significant effect -, for example, on the increase of the efficiency. The channels of the pump according to this invention can be technologically simple and therefore cheap to produce. The channels do not even have to be formed by vanes; they can be cylindrical and they can be, for example, drilled.

Since this is a hydrodynamic pump with low specific rotations, the simple shape of the channels (required by the technology of the production) is not a problem, too, since as is generally known, the lower the specific rotation the less effect the shape of the channels has on the efficiency. This manifests itself in the construction of the pump in such a way that the channels of the first stage have axial suction inlets in the zone of the axis of the rotation of the impeller. It is not a necessary condition, though, that the suction inlets of the channels are axial. Individual axial suction inlets of the channels of the first stage can be combined to a single common axial suction inlet for the channels of the first stage. The channels of the second stage have radial discharge outlets to the spiral for the discharge of the liquid. It is not a necessary condition, though, that the discharge outlets of the channels of the second stage are radial. A transferer is placed behind the impeller, whereby the axial outlets of the channels of the first stage flow or lead to the inlet of the transferer behind the circumferential zone of the impeller. It is not a necessary condition, though, that the outlets of the channels of the first stage are axial. The transferer is a stator part of the pump containing the vanes which lead the liquid towards the second-stage suction. Transfer through the transferer lowers the circumferential portion of the speed to zero. The outlet from the transferer leads to axial inlets of the channels of the second stage in the zone of the axis of the rotation of the impeller. It is not a necessary condition, though, that the inlets of the channels of the second stage are axial. If a second transferer is used on the opposite side of the common impeller, a three-stage pump can be created, where there are alternating channels of the first, second and third stage.

The advantages of the construction of the two-stage pump according to this invention are obvious looking at their outwardly manifested effects. In general it can be stated that this concerns a hydrodynamic pump where part of the channels of the same impeller operates in the first stage and part of the channels of the same impeller operates in the second stage. Such construction solution allows using hydrodynamic pump in case of low flow and high pressure. Compared to the typical solution of the pump with two impellers, this pump brings about the advantage of simple construction, lower number of moving parts (only a singe impeller), lower weight and smaller size. Abovementioned advantages stem from the fact that this is a two-stage pump, whereby the pump only contains a single impeller. This fact lowers the production and maintenance costs.

Two-stage pump according to this invention has an advantage of good throughput or passability of the solid particles, since it is capable to pump the mixtures of liquids and solid particles. It can be used to pump the liquid in the machine tools, where a good use is made of all these advantages. The invention brings compact construction with shorter shaft and lower inertia torque of the rotating parts as compared to the two-impeller two-stage pump. The shorter construction length is an advantage, too; this shorter length cannot be achieved in the typical arrangement with two impellers.

Brief description of drawings

The invention is further disclosed by figures 1 to 3. The used scale of the depiction and the ratio of sizes of individual elements, the depicted cross-section and shape of the channels cannot be interpreted as limiting the scope of protection. Figure 1 depicts - in form of a side, detailed cross-section - a scheme of the flow of the liquid from the inlet through the impeller to the outlet of the two-stage pump.

Figure 2 depicts a complete construction of the two-stage pump from the side. Figure 3 depicts a complete construction of the two-stage pump from the front.

Example of realization

It is understood that individual realizations according to this invention are intended for illustration purposes only, not for limitation of the technical solutions. A person skilled in the art will easily find - and will be able to find - many equivalents of specific realization of invention by use of no more than a routine experimentation. All such equivalents fall within the scope of the subsequent patent claims.

A person skilled in the art will have no problem with optimal setting of the construction and with choice of its particular components; therefore these aspects are not addressed in detail.

Example

In this example of the particular realization of the subject of the invention a construction of the two-stage pump is disclosed, which corresponds to the figures 2 and 3. The two-stage pump is composed from a system of the channels 4 of the first stage and the system of the channels 5 of the second stage, whereby the channels are alternately distributed on a single impeller 1_. The channels 4 of the first stage have axial suction inlets 6 in a zone of the rotation of the impeller 1_. The channels 5 of the second stage have radial discharge outlets 7 to the spiral 2 for the discharge of the liquid. A transferer 3 is placed behind the impeller 1_, whereby the axial outlets 8 of the channels 4 of the first stage lead to the inlet of the transferer 3 in the circumferential zone of the impeller 1_. The outlet from the transferer 3 leads to the axial inlets 9 of the channels 5 of the second stage in the zone of the axis of the rotation of the impeller 1

The function of the two-stage pump according to this invention can be explain by figure 1 , where the directions of flow are represented by arrows in the scheme. The liquid enters the impeller 1. in the direction represented by the arrow A. This arrow depicts the entrance of the liquid to these channels 4 of the impeller 1_ which operate in the first stage. The liquid leaves the channel 4 of the first stage in the direction represented by the arrow B and continues to the transferer 3. The arrow C represents the entry of the liquid from the transferer 3 to the channels 5 of the impeller 1 which operate in the second stage. The liquid leaves a channel 5 of the second stage towards the spiral 2, as represented by the arrow D.

Industrial applicability

Industrial applicability is obvious. According to this invention it is possible to industrially and repeatedly produce and use two-stage hydrodynamic pump, which can be preferably used in chemical industry, food industry, energy industry, and so on. It can be, for example used as an injection pump or lubrication pump.

List of related symbols - impeller

- spiral

- transferer

- channel of the first stage

- channel of the second stage

- suction inlet of the channels of the first stage- outlet of the channels of the second stage- outlet of the channels of the first stage- inlet of the channels of the second stage

Claims

PATENT CLAI MS

A two-stage hydrodynamic pump with a spiral (2) for a discharge of a liquid i s characterized by the fact, that it includes a system of channels (4) of a first stage and a system of channels (5) of a second stage which are alternately distributed on an impeller (1); the channels (4) of the first stage have suction inlets (6) in a zone of an axis of a rotation of the impeller (1) and the channels (5) of the second stage have discharge outlets (7) to a spiral

(2) for a discharge of the liquid; whereby a transferer (3) is placed behind the impeller (1); whereby axial outlets (8) of the channels (4) of the first stage lead to an inlet of the transferer (3) in a circumferential zone of the impeller (1); and an outlet from the transferer

(3) leads to axial inlets (9) of the channels (5) of the second stage in the zone of the axis of the rotation of the impeller (1 ).

The two-stage hydrodynamic pump according to the claim 1 i s characterized by the fact, that both stages of the pump are arranged in the single centrifugal impeller (1), whereby the channels

(4) of the first stage and the channels

(5) of the second stage are alternately distributed in a single plane on the impeller (1).

The two-stage hydrodynamic pump according to the claim 1 or 2 i s characterized by the fact, that the suction inlets

(6) of the channels (4) of the first stage are axial.

The two-stage hydrodynamic pump according to the claim 1 or 2 i s characterized by the fact, that the discharge outlets (7) of the channels (5) of the second stage are radial.

The two-stage hydrodynamic pump according to the claim 1 or 2 i s characterized by the fact, that the outlets (8) of the channels (4) of the first stage are axial.

The two-stage hydrodynamic pump according to the claim 1 or 2 i s characterized by the fact, that the inlets (9) of the channels (5) of the second stage are axial.

7. The two-stage hydrodynamic pump according to any of the claims 1 to 6 i s characterized by the fact, that the channels (4) of the first stage and/or the channels (5) of the second stage are cylindrical.

8. The two-stage hydrodynamic pump according to the claim 7 i s characterized by the fact, that the channels (4) of the first stage and/or the channels (5) of the second stage are drilled.

9. The two-stage hydrodynamic pump according to any of the claims 1 to 8 i s characterized by the fact, that it is a fuel injection pump.

10. The two-stage hydrodynamic pump according to any of the claims 1 to 8 i s characterized by the fact, that it is a lubrication pump.