Two-Stage Pump

The present invention relates to a pump for pumping at least one medium.

The prior art discloses different types of pumps. These allow different media such as gases or liquids to be moved. Some pump types are suited for gases and liquids or only for gases or liquids. Furthermore, with regard to the pumping of liquids, there are self-priming and non-self-priming pump types. Liquid ring pumps (see, for example, DE 199 13 632 C2) are known, for example, in which a liquid ring is formed due to the eccentric arrangement of a blade wheel, or also side channel pumps (see, for example, EP 0 118 027 B1), which are characterized by a conveying channel having an interrupter. The prior art also discloses the arrangement of different pump types one behind the other (see, for example, DE 24 62 187 A1 or DE 101 08 631 B4, DE 33 03 460 A1, DE 10 2007 013 872 A1 or DE 31 28 374 A1).

The object on which the invention is based is to propose a pump which represents an alternative to the prior art.

The object is achieved by the invention by a two-stage pump for pumping a medium, wherein the pump has a liquid ring stage, a side channel stage, and two medium accesses, wherein the liquid ring stage has a medium chamber and two medium openings, wherein the two medium openings of the liquid ring stage open onto the medium chamber of the liquid ring stage, wherein the side channel stage has a medium chamber and two medium openings, wherein the two medium openings of the side channel stage open onto the medium chamber of the side channel stage, and wherein one medium opening of the two medium openings of the side channel stage and one medium opening of the two medium openings of the liquid ring stage merge to form a common overflow opening.

The pump according to the invention has two stages: a liquid ring stage and a side channel stage. Therefore, the respective associated pumping principle is implemented in the stages. The pump has two medium accesses through which the medium—for example a gas such as air or a liquid such as water can flow in or out. Preferably, the pump can be operated in two directions such that the medium accesses are each inlets and outlets. Each of the two stages has an individual medium chamber and two medium openings through which the medium flows into or out of the respectively assigned medium chamber. One respective medium opening of the side channel stage and of the liquid ring stage merge to form a common overflow opening. The two stages therefore share one opening, such that the medium from one stage flows into the other stage via this common overflow opening. The pump according to the invention thus combines two different pump types to one unit which distinguishes itself by its compactness. A pump which is two-staged is in particular involved, rather than two separate pumps which are arranged one behind the other.

One embodiment consists in that the other medium opening of the two medium openings of the side channel stage and the other medium opening of the two medium openings of the liquid ring stage are connected to one respective medium access of the two medium accesses. In this embodiment, the medium openings which do not merge to the overflow opening are each connected to the medium accesses of the pump itself or form them in a further embodiment.

One embodiment provides that the liquid ring stage furthermore has a cover component, a bottom component and an impeller, that the cover component of the liquid ring stage and the bottom component of the liquid ring stage enclose the medium chamber of the liquid ring stage, that the medium chamber of the liquid ring stage has a circular cylindrical shape about a longitudinal axis, that the impeller of the liquid ring stage has blades extending from an axis of rotation, that the blades of the impeller of the liquid ring stage are arranged in the medium chamber of the liquid ring stage, and that the impeller of the liquid ring stage is arranged in relation to the medium chamber of the liquid ring stage such that the axis of rotation of the impeller is offset with respect to the longitudinal axis of the medium chamber. In this embodiment, the liquid ring stage is described in more detail. The impeller is arranged eccentrically in the circular cylindrical medium chamber.

One embodiment consists in that the side channel stage furthermore has a cover component, a bottom component and an impeller, that the cover component of the side channel stage and the bottom component of the side channel stage enclose the medium chamber of the side channel stage, that the bottom component of the side channel stage has a conveying channel having an interrupter, that the conveying channel is open to the medium chamber of the side channel stage, that the impeller of the side channel stage has blades extending from an axis of rotation, that the blades of the impeller of the side channel stage are arranged in the medium chamber of the side channel stage, that the medium chamber of the side channel stage has a circular cylindrical shape about a longitudinal axis, and that the impeller of the side channel stage is arranged in the medium chamber of the side channel stage so as to be rotatable about the longitudinal axis. This embodiment describes the side channel stage the medium chamber of which has a conveying channel having an interrupter. The impeller is arranged concentrically in the medium chamber.

One embodiment provides that the impeller of the side channel stage and the impeller of the liquid ring stage are configured in one piece. In this embodiment, the impeller of the side channel stage and the impeller of the liquid ring stage are formed by a one-piece component. In one configuration, the two blades are the two faces of a common support. In this embodiment, the two stages not only share a common overflow opening, but also a common impeller unit. Alternatively, the impellers are connected to each other so as to form a common unit.

One embodiment consists in that the bottom component of the liquid ring stage and the cover component of the side channel stage have a common intermediate component and that the intermediate component has the overflow opening. In this embodiment, the bottom component of the liquid ring stage and the cover component of the side channel stage partially coincide in that they use a common intermediate component. The overflow opening which connects the two medium chambers to each other is located in this intermediate component.

One embodiment provides that the pump pumps two different media. The pump is adapted to pump two different media. This is possible in that the two different pumping principles are combined in one unit.

One embodiment consists in that the medium is a gas or a liquid. If the pump pumps in particular two different media, this is preferably on the one hand a gas, for example air, and on the other hand a liquid, for example water.

According to one embodiment, it is provided that the pump furthermore has a motor, that the motor has two directions of rotation, and that one of the two medium accesses serves as a medium inlet or a medium outlet and the other of the two medium accesses as a medium outlet or a medium inlet depending on the direction of rotation of the motor. The pump can thus convey the at least one medium in two directions. To this end, a motor is present which is preferably coupled to the rotating component to move the impellers of the two stages. Depending on the direction of rotation, one medium access thus serves as a medium inlet and the other as a medium outlet. If the direction of rotation changes, the medium inlet becomes a medium outlet, and vice versa.

shows one embodiment of the two-stage pump in an exploded view.shows the pump in a section. Both illustrationsandwill be described together below.

The two stages of the pump are a liquid ring stageand a side channel stagewhich are both arranged directly one behind the other. The motorfor the pumping function is here exemplarily located behind the side channel stage. An arrangement (not shown) of the motorin front of the liquid stage ringis also possible. The pump has two medium accesseswhich serve to supply or discharge medium depending on the direction of rotation of the motor. The medium can be a liquid, such as water, or a gas, such as air.

The liquid ring stagehas a cover componentand a bottom component. In the illustrated embodiment, the cover componentis configured in two pieces by way of example. A medium chamberto which two medium openings,are connected, is formed between the cover componentand the bottom component. The axis of rotationof the impelleris offset with respect to the longitudinal axisof the circular cylindrical medium chamber. The rotation of the impellerthus causes the formation of the liquid ring. The individual bladesextend in a star shape from the axis of rotation.

The side channel stagealso has a cover componentand a bottom componentbetween which a medium chamberis formed-which is configured in a circular cylindrical manner. Two medium openings,also open onto the medium chamber. The medium is guided through the impellerin the conveying channel having an interrupter. Here, the interrupter can be seen below the medium opening. The axis of rotationof the impellerand the longitudinal axisof the medium chambercoincide. The bladesof the impellerextend in a star shape from the axis of rotation.

These two stages,partially share individual components. This is described below.

A medium openingof the liquid ring stageand a medium openingof the side channel stagemerge to form a common overflow opening. The medium thus flows out of a stageordirectly into the respective other stageor. The other medium openingof the liquid ring stageand the other medium openingof the side channel stageform the medium accessesof the pump.

The overflow openingis located in the intermediate componentwhich belongs to the bottom componentof the liquid ring stageand to the cover componentof the side channel stage. It can therefore also be stated that the bottom componentof the liquid ring stageand the cover componentof the side channelmerge to form a common component.

In addition to the overflow opening, a circular recess in which the rotating componentis rotatably arranged is also located in the intermediate component. The rotating componentcomprises the impellerof the liquid ring stageand the impellerof the side channel stage. The two impellers,are located on different faces of a support of the rotating component, which is arranged in the circular recess of the intermediate component. A sealing effect is reached between the edge about the recess and the support of the rotating component, so that the bottom componentof the liquid ring stageand the cover componentof the side channel stageallow the medium to pass substantially only through the overflow opening.

The rotating componentis configured and the respective blades,are arranged such that the axis of rotationof the impellerof the liquid ring stageand the axis of rotationof the impellerof the side channel stagecoincide. The longitudinal axisof the medium chamberof the side channel stageis also located along this common axis,. It can be seen that the bladesof the impellerof the liquid ring stagehave a greater axial extent than the bladesof the impellerof the side channel stage.

Illustrations a) and b) ofshow the medium chamberof the liquid ring stage. Illustration a) ofshows a medium openingof the liquid ring stageand a medium openingof the side channel stage. Furthermore, the medium openingof the liquid ring stageis visible, through which the transition between the liquid ring stageand the side channel stageoccurs. Illustration b) ofshows the asymmetric arrangement of the impellerin the medium chamber. The axis of rotationof the impelleris here arranged above the longitudinal axisof the circular cutout of the edge of the medium chamber. Therefore, a larger volume is present below the bladesof the impeller, in which the liquid ring can form.

Illustrations a) and b) ofshow the medium chamberof the side channel stage. As can be seen in illustration a) of, the impelleris located centrally in the medium chamber. Furthermore, the medium openingin the cover componentcan be seen, which is located above the axis of rotationof the impeller. Illustration b) ofshows the bottom componentin which the conveying channel having the interrupteris located. In this view onto the rotating component, it can also be seen that the bladesof the impellerof the side channel stagehave a significantly greater radial extent than the bladesof the impellerof the liquid ring stage.

When used for two different media, the pump has an optimum performance for the respectively conveyed medium, depending on the direction of rotation:

If a rotation occurs in one direction, for example in a clockwise direction, the conveyance is optimally adapted for gases. The liquid ring stage is active. The side channel stage does not cause any pressure increase, it is passive.

In the event of a counterclockwise rotation, liquids can be conveyed in an optimal manner. The pressure increase occurs in the side channel stage. The liquid ring stage contributes only little to the pressure increase.