EP0118027A2 - Self-priming lateral channel pump - Google Patents

Abstract

1. Self-priming lateral channel pump having a housing with an inlet opening (12), outlet opening (13) and incorporated lateral channels, having at least one impeller (32) with impeller cells which are arranged in at least two coaxial rings of cells or different diameters so that a flow medium reaches first the inner and then the outer impeller cells, while the lateral channel/channels directly connected to the outlet opening extend(s) completely over the impeller cells associated therewith and this/these lateral channel/channels (17, 17') is/are provided only over part of the circumference, whilst the inlet opening(s) of the lateral channel/channels associated with the inner impeller ring/rings is/are arranged in the near-axis portion and this/these lateral channel/channels (17, 17') is/are continued after (a) transitional opening(s) (19, 19') via (a) terminal secondary displacement channel/channels (20, 21'), characterized in that the lateral channel/channels (17, 17') connected to the inlet opening (12) of the housing extend(s) partially over the associated impeller cells (33, 33') in such a way that the portions of the impeller cells (33, 33') which are not overlapped, namely the near-axis portions, are sealed off by the the housing (16, 16'), whilst the transitional opening(s) (19, 19') of the lateral channel/channels (17, 17') associated with the inner ring/rings of impeller cells (33, 33') is/are arranged in the near-axis portion.

Description

The invention relates to a self-priming side channel pump, which is suitable for generating high pressures with a high suction head.

To achieve high pressures, side channel pumps are suitable, the vane cells of which are at least axially, in addition often also radially open, and to which side channels are assigned which completely cover the openings of the vane cells. In this way, optimal energy transfer is possible by exchanging impulses from the faster rotating blade fluid to the slower volume flow in the side channel. Furthermore, in order to achieve high pressures, care is taken to ensure that the volume flow conveyed in the side channel undergoes as little change of direction as possible when it enters and exits from the side channel. For this purpose, the inlet and in particular the outlet are guided outwards in the circumferential direction directly at the beginning or end of the side channel. The sensitivity to impurities in the pumped medium and the pressure loss due to the inward conveying of the pumped medium can be reduced or avoided, but on the other hand this measure of direct connection means that the ability of the side channel pump to self-priming is lost, since no liquid ring that displaces the sucked-in air can form. after the liquid present in the pump due to the initial filling is drained off immediately when restarting.

There are special types of side channel pumps known, in which the direct connections of suction and pressure ports through lateral, that is, axially arranged Connections are replaced to come close to immediate self-priming. However, the efficiency of the pump is considerably impaired by this arrangement, the suction and venting times of such pumps are nevertheless very long.

From DE-OS 30 14 425 a special version of a side channel pump is known, in which the blade cells are provided in an alternating length to the impeller hub, so that shorter and longer blade blades alternate (seen in the radial direction). These alternatingly long vane cells are opposed by a side channel with a decreasing cross-section, which covers the long and short vane cells at the beginning, but only the short vane cells at the end. This construction improves the air delivery of the side channel pump, but the suction and venting times are still quite long. In addition, the long suction times, especially in the case of long suction lines, lead to heating which can cause defects. In addition, the heating increases the vapor pressure of the liquid required for the self-priming process within the pump, which results in a decrease in the suction height that can actually be achieved.

From US-PS 23 21 810 a self-priming centrifugal pump is known, the rotor of which has two impeller rings. Opposite the outer impeller ring is a side channel that completely covers the impeller cells and is directly connected to the pressure opening of the pump. This outer side channel is, as is generally known in peripheral wheel pumps, only over part of the Guided circumferentially and has an overflow channel at its input end, which is connected to an inner housing space assigned to the inner blade cells. Although this known pump has a certain ability for self-priming, the suction height achievable with this arrangement is limited. In addition, the achievable pressure at the pump outlet is relatively low, since only a low pressure is specified for the external pressure stage.

Starting from the above-mentioned prior art, it is an object of the present invention to design a directly self-priming side channel pump in such a way that a high energy transfer number (pressure coefficient) is achieved with good efficiency and self-priming behavior, that is to say short priming or venting times.

This object is achieved by a pump according to the main claim, further preferred embodiments result from the subclaims.

In the case of the present pump, the impeller is in a constructional unit both with star-shaped blade cells, with long blade cells extending from the impeller hub and extending in the circumferential direction and with at least one larger-diameter, preferably double-sided blade cell ring with axially or axially and radially open blade cells and short ones Shovels trained. Here are the star-shaped inner blade cells either open continuously in the axial direction on both sides, or else are separated from one another by a central wall. Opposite the blade cells are side channels each with an interrupter, which only partially cover the long blades in the direction of the hub and completely cover the short blade cells.

In a further preferred embodiment of the pump according to the invention, the inner blade ring with associated side channels, which acts as a liquid ring “preliminary stage”, is connected upstream of several pump stages of blade cells connected in series and completely covering side channels with interrupters. The following blade rings are thus arranged with increasing diameters in the impeller, which results in a particularly compact design with a very high final head and still good sowing behavior.

The construction according to the invention has the advantage that by combining the delivery elements of a directly self-priming liquid ring side channel pump with the delivery elements of a side channel system which is considerably better in terms of efficiency and pressure, but not self-priming in one construction unit, a particularly compact, material-saving high-pressure pump with good self-priming properties and good efficiency arises. Since all the pump elements are arranged on only one impeller, the adjustment of the impeller in the housing is not nearly as critical as in the case of the conventional pumps with a suction stage upstream, which are designed to achieve the pressure figure achieved here. In addition, the Design of the pump according to the invention improves the efficiency compared to conventional pumps, in particular by virtue of the fact that the inner side channel pump, which operates as a liquid ring pump, in this multi-stage version as a feed pump, accelerates the volume flow entering the housing at a relatively low flow velocity through the inlet opening into the next stage rotating at a greater peripheral speed . In this way, the acceleration shock which otherwise leads to considerable losses when the blade enters the "pressure stage" is reduced to a minimum.

• Figur 1 einen Längsschnitt durch eine bevorzugte Ausführungsform der erfindungsgemäßen Pumpe entlang der Linie I-I aus Figur 2.
• Figur 2 einen Querschnitt durch die Pumpe nach Figur l mit strichpunktiert angedeutetem Laufrad und strichliert gezeichnetem überströmkanal,
• Figur 3 eine Aufsicht auf das Laufrad nach den Figuren 1 und 2,
• Figur 4 einen Schnitt durch das Laufrad nach Figur 3 entlang der Linie II-II aus Figur 3,
• Figur 5 eine Aufsicht auf eines der Seitenkanalteile der Pumpe nach den Figuren 1 und 2,
• Figur 6 einen Schnitt durch das Seitenkanalteil nach Figur 5 entlang der Linie III-III,
• Figur 7 einen Längsschnitt durch eine weitere bevorzugte Ausführungsform mit einseitigem Innen-Zellenkranz und doppelseitiger Druckstufe,
• Figur 8 einen Längsschnitt durch das Laufrad der Pumpe nach Figur 7 entlang der Linie IV-IV aus Figur 9,
• Figur 9 eine Aufsicht auf das Laufrad der Pumpe nach Figur 8,
• Figur 10 einen Längsschnitt einer weiteren bevorzugten Ausführungsform der Pumpe mit einseitiger Vorstufe und doppelseitiger Druckstufe,
• Figur 11 einen Schnitt durch das Laufrad der Pumpe nach Figur 10 entlang der Linie V-V nach _ Figur 12,
• Figur ₁₂ eine Aufsicht auf das Laufrad der Pumpe nach Figur 11,
• Figur 13 die Aufsicht auf eine weitere bevorzugte Ausführungsform eines Laufrades mit beidseitig offenen Schaufelzellen der Vorstufe und doppelseitigen, axial offenen Schaufelzellen der Druckstufe mit strichpunktiert angedeuteten Seitenkanälen und Ein-/Austrittsöffnungen,
• Figur 14 einen Schnitt durch das Laufrad nach Figur 13 entlang der Linie VI-VI,
• Figur 15 eine Aufsicht auf das Laufrad einer weiteren bevorzugten Ausführungsform der Pumpe mit doppelseitigen, durch eine Mittelwand getrennten Schaufelzellen der Vorstufe und mehreren nachfolgenden, doppelseitigen Druckstufen mit axial und radial offenen Schaufelzellen und strichpunktiert angedeuteten Seitenkanälen mit Ein-/Austrittsöffnungen,
• Figur 16 einen Schnitt durch das Laufrad nach Figur 15 entlang der Linie VII-VII,
• Figur 17 eine Aufsicht auf ein Laufrad einer weiteren bevorzugten Ausführungsform der Pumpe mit doppelseitigen, durch eine Mittelwand voneinander getrennten Schaufelzellen der Vorstufe und mehreren nachfolgenden, doppelseitigen Druckstufen mit axial und axial/radial offenen Schaufelzellen und strichpunktiert angedeuteten Seitenkanälen mit Ein-/Austrittsöffnungen, und
• Figur 18 einen Schnitt durch das Laufrad nach .. Figur 17 entlang der Linie VIII-VIII.

Further features of the pump according to the invention result from the following description, which are explained in more detail with reference to exemplary embodiments and drawings. Here shows

• 1 shows a longitudinal section through a preferred embodiment of the pump according to the invention along the line II of Figure 2.
• FIG. 2 shows a cross section through the pump according to FIG. 1 with the impeller indicated by dash-dotted lines and the overflow channel shown in dash-dotted lines,
• FIG. 3 shows a top view of the impeller according to FIGS. 1 and 2,
• FIG. 4 shows a section through the impeller according to FIG. 3 along the line II-II from FIG. 3,
• FIG. 5 shows a top view of one of the side channel parts of the pump according to FIGS. 1 and 2,
• FIG. 6 shows a section through the side channel part according to FIG. 5 along the line III-III,
• 7 shows a longitudinal section through a further preferred embodiment with one-sided inner cell ring and double-sided pressure stage,
• 8 shows a longitudinal section through the impeller of the pump according to FIG. 7 along the line IV-IV from FIG. 9,
• FIG. 9 shows a top view of the impeller of the pump according to FIG. 8,
• FIG. 10 shows a longitudinal section of a further preferred embodiment of the pump with one-sided preliminary stage and double-sided pressure stage,
• FIG. 11 shows a section through the impeller of the pump according to FIG. 10 along the line VV according to FIG. 12,
• FIG. _{12 shows} a top view of the impeller of the pump according to FIG. 11,
• FIG. 13 shows the top view of a further preferred embodiment of an impeller with blade cells of the preliminary stage that are open on both sides and double-sided, axially open blade cells of the pressure stage with side channels and inlet / outlet openings indicated by dash-dotted lines,
• FIG. 14 shows a section through the impeller according to FIG. 13 along the line VI-VI,
• FIG. 15 shows a top view of the impeller of a further preferred embodiment of the pump with double-sided blade cells of the preliminary stage separated by a central wall and a plurality of subsequent double-sided pressure stages with axially and radially open blade cells and side channels with dash-dot lines with inlet / outlet openings,
• FIG. 16 shows a section through the impeller according to FIG. 15 along the line VII-VII,
• Figure 17 is a plan view of an impeller of a further preferred embodiment of the pump with double-sided, separated by a central wall vane cells of the preliminary stage and several subsequent, double-sided pressure stages with axially and axially / radially open vane cells and dash-dot side channels with inlet / outlet openings, and
• Figure 18 shows a section through the impeller according to .. Figure 17 along the line VIII-VIII.

The preferred embodiment of the pump according to the invention shown in FIGS. 1 to 6 shows a double-flow side channel pump with a liquid ring preliminary stage and consists of a housing 10 and an impeller 32. The housing 10 is constructed in several parts and consists of a housing ring 11 with an inlet opening 12 and an outlet opening 13 , an end housing cover 14, a drive-side bearing cover 15 and the two side channel parts 16 and 16 '. In the side channel parts 16 and 16 'are the pre-stage side channels 17 and 17', the pre-stage inlet openings 18 and 18 ', the pre-stage outlet openings 19 and 19', re-displacement channels 20 and 20 'with ventilation holes 21 and 21', transfer channels 22 and 22 ' Pressure stage side channels 23 and 23 ', pressure stage inlet openings 24 and 24', pressure stage outlet openings 25 and 25 ', and interrupters 26 and 26' are arranged.

The housing cover 14 and the bearing cover 15 are sealed in the housing ring 11 by round cord rings 27 and screwed to the housing ring 11 with housing screws 42.

In the bearing cover 15 of the housing 10, a shaft 30, which is sealed by packing rings 29, is mounted and is rotated in the direction of the arrow (FIG. 2) by a drive motor, not shown, for example an electric motor. The impeller 32 is fastened to the free end of the shaft 30 by means of a feather key 31.

The two-stage impeller 32 consists of blade cells 33 arranged in a star shape, the blades 34 of which have a roof-shaped backing for reinforcement and form the impeller preliminary stage, and of the axially and radially open blade rings 35 and 35 ', which form the impeller compression stage.

The rotating blade cells 33 of the impeller preliminary stage form a liquid ring from the liquid content in the housing, which fluid ring fills the annular preliminary stage side channel 17 and at the same time the blade cells 33 to the wheel circumference. When the rotating vane cells reach the area of the side channel beginning, part of the vane cell content belonging to the liquid ring is forced into the side channel 17 by the centrifugal force. The liquid ring thus moves away from the impeller hub and sucks in air through the preliminary stage inlet opening 18. Due to the steady increase in pressure in the side channel 17, caused by the exchange of impulses between the liquid content of the blade cells 33 and the volume flow in the side channel 17, liquid is pushed back from the side channel 17 into the blade cells 33. As a result, the air enclosed in the hub region of the blade cells 33 is compressed. At the end of the side channel 17, the liquid is forced back into the vane cells 33 by a post-displacer 20 that runs flat in the axial direction, as a result of which the compressed air is pressed through the vent hole 21.

The air flow, i.e. the self-priming process, continues until the suction line and the inside of the pump are vented. In the immediately following liquid conveyance, the volume flow entering through the inlet opening 12 in the housing 10 and the pre-stage inlet opening 18 into the pre-stage side channel 17 experiences an energy transfer through the exchange of impulses between the higher flow energy state and the volume flow lower from the vane cells 33 formed by centrifugal force Energy state in the side channel 17. The conveyed medium flows through the side channel 17 from the beginning of the side channel to its outlet opening 19 and passes through the transfer channel 22 into the inlet opening 24 and thus into the pressure stage side channel 23. When the pressure stage side channel 23 flows through, a further energy supply or pressure increase occurs through impulse exchange between the blade cells 38 and the volume flow in the side channel 23. In the end, the side channel 23 merges directly into the connected outlet opening 25 in the housing 10, so that the volume flow does not experience an abrupt change in direction.

FIGS. 7 to 9 show a further preferred embodiment of the pump according to the invention. In this pump, the preliminary stage feed cells 33 of the impeller 32 are arranged on one side, that is to say in one flow, and are open in the axial direction. The pressure equalization between both sides of the impeller 32 takes place through pressure equalization bores 40 which are only provided in part of the blade cells 33. In this embodiment, the inner blades 34 are arranged flush with the impeller end face, as was also shown in the embodiments according to FIGS. 1 to 6.

In a further preferred embodiment of the pump according to the invention, as shown in FIG. 10, the inner blades 34 stand from the impeller 32 with which they. are integrally connected, and are open in both the axial and radial directions. The side channel assigned to them accordingly comprises the inner blade cells partially in the radial direction and entirely in the axial direction. In this way, a further increase in the efficiency of the pump can be achieved. In the present case, the inner step is only single-flow, but a double-flow design is also possible.

Further details of the impeller can be seen in FIGS. 11 and 12, in which the roof-shaped stiffeners of the inner blades 34 are also shown.

FIGS. 13 and 14 show the impeller of a further preferred embodiment of the pump according to the invention. Here, the inner blade cells 33 are designed to be open on both sides, with side channels opposite them on both sides. The subsequent pressure stage is formed by the blade cells 38 and 38 'with associated side channels, these outer blade cells 38 and 38' only being open in the axial direction.

FIGS. 15 to 18 show further preferred embodiments of the pump according to the invention based on its impellers. The impeller according to FIGS. 15 and 16 has inner vane cells 33 and 33 'which are separated by a central wall 36 and which are flush with the impeller 32. The inner blade cells 33 and 33 'are followed by two further pressure stages 38a, 38b and 38'a, 38'b, also connected in series. The blade cells of the pressure stages are designed to be radially and axially open, opposite them are the correspondingly shaped side channels which completely cover the blade cells. In the embodiment of the pump according to FIGS. 17 and 18, in contrast to the previously described embodiment, the first pressure stage is designed with only axially open blade cells 38a, 38'a.

The depth and arrangement of the blade cells of the various blade cell rings is selected in accordance with the required funding conditions, as well the one- or two-flow formation of the different pressure levels.

Claims (7)

1.Self-priming side channel pump with a housing with inlet opening, outlet opening and integrated side channels, with at least one impeller with blade cells which are arranged in at least two coaxial blade cell rings of different diameters in such a way that a conveying medium first reaches the inner, then the outer blade cells, whereby the side channel (s) directly connected to the outlet opening completely covers the blade cells assigned to him / her, characterized in that the side channel (s) / side channels (17, 17 ') connected to the inlet opening (12) ) partially covering / covering the blade cells (33, 33 ') assigned to him / her in such a way that the uncovered, namely near-axis portions of the blade cells (33, 33') are sealed by the housing (16, 16 '), and this / these side channel (s) (17, 17 ') are only provided over part of the circumference, the inlet opening (s) (18 , 18 ') and the outlet opening (s) (19, 19') of the side channel / side channels (17, 17 ') associated with the inner vane cell rim or rings (33, 33') are arranged in the section near the axis and this / these side channel (s) (17, 17 ') after the outlet opening (s) (19, 19') via (one) outlet (s) redisplacement channel (s) (20, 20 ') with assigned outlet opening (21 , 21 ') is / are continued. 2. Side channel pump according to claim 1, characterized in that the axially close blade cells (33) pass in the axial direction through the impeller (32). 3. Side channel pump according to claim 1, characterized in that the axially close blade cells (33,33 ') are closed on one side in the axial direction by a wall (36,37) of the impeller (32), the wall (36,37) preferably by some pressure equalization holes (40) is broken. 4. Side channel pump according to one of the preceding claims, characterized in that the axially close blade cells (33, 33 ') are flush with the impeller (32) in the axial direction. 5. Side channel pump according to one of claims 1 to 3, characterized in that the axially close blade cells (33) in the axial direction from the impeller (32) are arranged in a projecting manner and are open in the axial and radial directions. 6. Side channel pump according to one of the preceding claims, characterized in that the axially close blade cells (33,33 ') with side channels (17,17') several gradually increasing in diameter, preferably double-sided pressure stages with blade cells 38a, 38'a, 38b, 38'b) are connected in series with the corresponding side channels (23a, 23b, 23'a, 23'b) which completely cover them. 7. Side channel pump according to one of the preceding claims, characterized in that the outer blade cells (38,38 ', 38a, 38b, 38'a, 38'b) are radial, optionally also axially open.

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