WO1991011619A2

WO1991011619A2 - Side channel pump

Info

Publication number: WO1991011619A2
Application number: PCT/EP1991/000170
Authority: WO
Inventors: Josef Reihansl
Original assignee: Reihansl Maschinen + Pumpen Maschinen- U. Pumpenbau Gmbh
Priority date: 1990-01-31
Filing date: 1991-01-30
Publication date: 1991-08-08
Also published as: HU913073D0; WO1991011619A3; HUT62374A; EP0465626A1

Abstract

The description relates to a side channel pump, the casing of which may be assembled from two disc-shaped halves (10'), in each of which is made at least one side channel (15a, b, c). A paddle wheel (11) arranged between the halves (10') conveys the medium by means of rings of blades (23) allocated to the side channels (15a, b, c). Slip-rings (20, 21) are arranged on the paddle wheel (11) and/or the halves (10') in the region of the lateral sealing surfaces. The inlet channel (25) and the transition between two side channels (15a, b, c) open at an acute angle in the plane of separation between the halves (32) and tangentially to the side channel centre line into the corresponding side channel (15a, b, c). The opening (26) of the inlet channel is widened in the form of a hopper towards the outside of the casing half (10') and that of the overflow channel (29, 29') merges into the appropriate side channel.

Description

5-SIDE CHANNEL PUMP

The invention relates to a side channel pump with a housing that can be assembled from two shells, a disk-shaped blade wheel arranged therein with at least two blade rings, which are arranged on both sides of the disk plane of the blade wheel, and with an associated drive shaft, two flow channels that start from a common suction opening in the housing and lead to a common outlet opening in the housing via at least one side channel step formed in the housing and associated blade cells of a blade ring. The two flow channels are separated by the to the periphery of ^a Sch ufel¬ wheel disc through the impeller. In such a pump, the blade cells of each blade ring are alternately long and short in the radial direction. Each side channel has an outer contour which is concentric with the bucket wheel axis and a spiral-shaped inner contour. The radius vector of the spiral-shaped inner contour corresponds to the distance of the bottom of a long blade cell from the shaft at the suction opening and to the distance of the bottom of a short blade cell from the shaft at the outlet opening. In the case of a multi-stage side channel pump, at least one transition channel is formed in each of the two side walls of the housing, which connects the end of a side channel stage to the beginning of the stage that follows in the radial direction.

Such a side channel pump is known from DE-PS 30 14 425. Although this has a good steady-state performance characteristic, with rapid pressure changes there is a risk, when using tight sealing gaps between the impeller and the housing, that the impeller touches the adjacent housing parts, whereby the blades are usually damaged and the wheel is even damaged can fix. If you increase the sealing gap, the efficiency and the achievable pump pressure decrease. There are also pumps which are equipped with slide rings to improve their efficiency. In British Patent 14 48 578, for example, a side channel pump is described in which an annular seal reduces the gap between the impeller and the housing. In this pump, however, the side channels in the housing halves on the right and left of the impeller are not separated by the latter, but are connected via the blades. The blades of the impeller therefore act on a single volume flow and the impeller is not fixed in the axial direction.

The same applies to the pump described in German Offenlegungsschrift 22 20 076. Multistage is only possible with this type of pump by connecting in series in the axial direction. Intake and discharge ports must then be arranged on different sides of the impeller. The pressure difference causes a ent speaking axial thrust, this is also compare German Offenlegungsschrift 24 05 112. In addition, a peripheral pump 247,725 is described in DDR patent having axially and radially movable and axially and radially split ^• sealing rings.

The invention is therefore based on the object of providing a side channel pump of the type described above, which is even more reliable in operation, is suitable for generating very high pressures, in which rapid pressure changes are also mastered and their efficiency is improved.

This object is achieved according to the invention by a side channel pump of the type described at the outset, which is characterized in that sliding rings are arranged on the impeller and / or the housing shells in the region of the lateral sealing surfaces and that the inlet channel and, in the case of multiple stages, the Angle to the parting plane of the housing halves and tangential to the imaginary side channel center line open into the corresponding side channel, the mouth -g of the inlet channel to the outside of the housing shells being funnel-like, and the mouth of each transition channel continuously running out in the side channel.

The slide rings are preferably made from carbon graphite or polytetrafluoroethylene (PTFE).

In a preferred embodiment, a carbon graphite impregnated with synthetic resin, a carbon graphite impregnated with antimony or a carbon graphite or glass fiber-reinforced PTFE or carbon-reinforced PTFE treated with a special impregnation approved for food use is used as the sliding ring material.

Other slide ring materials that can be used are: special chrome cast, special chrome molybdenum cast iron, stellitized CrNiMo steel, Hastelloy B-2 (2.-4617),

Hastelloy C (2.4619 or 2.4819), cobalt-bonded tungsten carbide, nickel-bonded tungsten carbide, Si-SiC (reaction-bonded silicon carbide), SiC (pressure-free sintered silicon carbide), C-SiC (surface-siliconized carbon), C-SiC-Si ( silicon-impregnated carbon), aluminum oxide 97.5%, aluminum oxide 99.5%.

Preferably, the slide rings are bonded into annular grooves in the area of sealing surfaces or pressed, whereby the slip rings rise a little above ^'the areas in which they are embedded.

In the side channel pump according to the invention, the impeller rotates without contact between the opposite housing halves. The gap width between the impeller and the housing depends on the material used for the impeller, the delivery quantity and the delivery pressure and is usually in the range of 0.1-0.2 mm per sealing gap. In large _ß s and rapid pressure changes in the pump Seitenkanal¬ strong axial forces may occur which may _b ewirken a side contact of the impeller and the housing in the periph- ren area. This can damage the pump or even jam it. To avoid this, sliding rings are used in the area of the lateral sealing gaps of the impeller and / or the housing halves, which prevent direct contact between the impeller and the housing. The efficiency can be reduced mm 0.05, thereby also of the pump is improved - by this Maß¬ na me _h addition, the conventional sealing gap width may be about 0.01.

A further improvement in the efficiency is surprisingly achieved by the above-mentioned design of the entry and transition channels and their outlets into the associated side channels.

The inner contour of a side channel is preferably designed like an Archimedean spiral, i.e. it has a smaller distance from the wheel axle at its beginning (at the entry opening) than at its end. The side channel thus becomes narrower from its beginning to its end, its volume less. The from the suction opening, i.e. Entry channel coming from outside is preferably guided through the side wall of the corresponding housing half near the axis.

The transfer channels which, in the case of a multi-stage side channel pump, mark the end of a side channel stage with the beginning of the radially following one. Connect level will be advantageous over the

Guided outside of the corresponding housing half. In this case, at the end of the one side channel there is an outlet leading through the housing wall to the outside and in the vicinity of the outlet in the next side channel stage. The side channels of a multi-stage embodiment are arranged concentrically. The entrance of the second side channel following the first side channel is therefore radially offset from the exit of the first side channel and is only offset so far downstream that the shortest possible, streamlined route is made from said outlet of the first side channel to the entrance to the second side channel can. Said transition channel is advantageously designed as a closed chamber which, on the outside of the housing half, contains the outlet of the one and the inlet of the subsequent side channel. These transition chambers are advantageously closed with a removable cover, so that the entrances and exits of the side channels are easily accessible from the outside.

The inlet and transition channels or their passages through the side wall of the respective housing half and their mouth areas in the side channels are shaped in such a way that a continuous flow with minimal resistance is ensured. Each entrance to a side channel is therefore funnel-shaped to the outside. The central axis of the funnel-shaped extension is arranged at an acute angle to the ^' imaginary, parting plane of the housing halves and tangential to the (imaginary ^* center line of the corresponding side channel. The exit of a side channel into a transition channel or into a transition chamber can occur when passing through the outer wall of the housing be expanded approximately to the diameter of the funnel-shaped widening of the associated inlet opening of the subsequent side channel.

Such an outlet and / or inlet extension is advantageous if one wishes to achieve a corresponding slowdown and calming of the flow in the transfer channel or in the transfer chamber. This further reduces the flow disturbances associated with the change in direction of transition. Such a construction is particularly advantageous if the transfer of the medium in a transfer step chamber takes place. A pump housing with a transfer chamber is generally simpler and cheaper to manufacture than a housing with a closed transfer channel. In case of a

Transition chamber, it is only necessary to enter and

To design the fluidic outlet in the manner described above.

If the passage is through a closed channel, it is guided from the end of one side channel in a slight arc over the outside of the housing to the entrance of the next side channel in such a way that its center line has a flat (acute) angle at its beginning and at its end forms with the parting plane of the disc-shaped housing half.

If the pump is to generate high pressure, it is preferably built radially in several stages and the concentric side channels become smaller in cross-section from stage to stage. The transition channels between the individual stages are then preferably adapted to these cross-sectional changes in the side channels from stage to stage. In such a case, therefore, the transfer channel tapers in the direction of flow from a cross-sectional area which corresponds to that of the end of the one side channel to a cross-sectional area which corresponds to that of the beginning of the subsequent side channel step.

The above erwä _h nth acute angle, in which the inlet and _Ov ertritts _k Anaele into the corresponding lateral channels a ^¬ en Coin _d is preferably in the range of about 10 to about 35 _°, pecial to _b at about 20 °. Among these angles is carried AUC he _hd _A ustritt at the end of the side channel in a standing talking ent ^¬ _h s _d s _Ov ertrittskanal or in an overflow chamber. 1 The paddle wheel of a pump according to the invention is a disk which is provided with paddle cells on both sides and the paddle cells are arranged in concentric rings (rings). For each vane cell ring 5 there is a side channel in the housing. The impeller and the two housing halves or housing shells are preferably designed with mirror symmetry, based on the imaginary center plane of the impeller disk. In this case, the parting plane of the two housing halves preferably coincides

10 of the mentioned central plane of the impeller disk together. Such a mirror-symmetrical embodiment has the advantage that the forces acting on the paddle wheel largely compensate each other. In addition, the flow inlets and outlets of each housing half can then

15 can easily be summarized in a suction opening and an outlet opening. The paddle wheels used in the pump according to the invention correspond to those of German Patent 30 14 425 (corresponds to US Pat. No. 4,408,952).

20 The position of the impeller is preferably in the

Pump fixed in relation to the two housing halves so that the sealing surfaces on the housing and impeller do not touch and at most the sliding rings are in slight contact. After a few hours of operation (when the pump is

25 is running), the impeller should therefore rotate without contact between the two housing halves, the sealing gaps between the slide rings being extremely small. Surprisingly, a pump according to the invention with a stationary (axially fixedly positioned) impeller has one

30 better and longer lasting efficiency than the known pumps, whose impeller is not fixedly positioned between the housing halves, but is axially movable (slidable).

-35 Description of exemplary embodiments of the invention with reference to drawings. Show it:

5

1 shows a longitudinal section through a known side channel pump according to DE-PS 30 14 425

Fig. 2 is a view of the inside of a housing half with ig inserted sliding rings for a three-stage pump

3 shows a section in the plane III / III of FIG. 2,

4 shows a view of a three-stage impeller with inserted sliding rings

5 shows a section through an impeller according to FIG. 4

Fig. 6 is a view of the outside of a housing half

20 a two-stage pump

7 shows a section along the line A-B according to FIG. 6

8 shows a section along the line C-D according to FIG. 6

25

FIG. 9 is a view of the inside of the two-stage housing half shown in FIG. 6

10 shows a section along the line E-F according to FIG. 6

30

11 shows a section along the line L-M according to FIG. 6

12 shows a section along the line G-M according to FIG. 6

gg Fig. 13 is a perspective view of a housing half of a two-stage pump, cut approximately 1/4. The side channel pump shown in Fig. 1 is known.

It is constructed in one stage and consists of a housing 10 and an impeller _11. The housing 10 is composed of a housing ring (9) with a suction opening (13) and outlet opening (14), a bearing cover (8), a housing cover (7) parallel to it and two housing disks (5, 6), which are located between the Bearing cover (8) and the housing cover (7) in the housing ring (9) are attached. The impeller (11) designed as a disk is provided on both sides with a ring of blade cells (16).

Two examples of embodiments according to the invention are shown in FIGS. 2-13.

Figures 2-5 show a three-stage pump, Figures 6-13 a two-stage.

Figure 2 shows the inside of a housing half (10 *). One looks at three side channels (15 a, b, c), which are arranged concentrically one above the other. The open sides of the said side channels face the viewer. Two such housing halves (10 ') together with a paddle wheel, as shown in Figures 4 and 5, form a complete pump. Each side channel (15 a, b, c) extends over an arc of approximately 270 °. Each side channel has a circular outer contour (18) and an inner contour (17) which approaches the outer contour slightly in the direction of flow, ie towards the end of the side channel, so that it has the overall course of an Archimedean spiral. The side channels (15 a, b, c) are separated by circumferential sealing surfaces (19). Slip rings (20, 20 ") are fastened to these sealing surfaces. The fastening is preferably carried out by inserting and gluing in corresponding ring grooves. The sectional view in FIG. 3 shows this more clearly.

10 The said slide rings rise only very slightly above the surface of the sealing surfaces (19).

The pump medium enters the first side channel (15a) at the mouth of the inlet channel (26). This channel has the

, - smallest radius. The first vane ring (23) of the vane wheel (11) shown in FIGS. 4 + 5 transports the medium over a circular arc of approximately 270 ° to the end (30) of the side channel (15a). There the medium leaves the first side channel through the outlet opening (30). A not

20 shown transition channel or a transition chamber allows the medium to pass over the outside of the housing half (10 ¹ ) into the second side channel (15b). At the mouth (29) it enters the second side channel (15b). From the second blade ring (23 ') of the in Figures 4 and

25 5 shown paddle wheel (11), the medium is transported again over about 270 ° to the end of this side channel. There is again a transition over the outside of the housing halves (10 ') from the outlet opening (30') to the inlet opening (29 ') of the third side channel (15c).

30 Finally, the medium is conveyed from the third blade ring (23 '') of the blade wheel (11) shown in FIGS. 4 and 5 to the outlet (27). Small vent holes (24) can be provided at the end of the first two side channels to allow air to escape, which may have remained in the blades gc of the blade wheel. The sectional view of Figure 3 (section along the line 111 /

III of FIG. 2) shows more clearly the slide rings (20, 20 ') inserted in the ring grooves and the arrangement of the side channels (15a, b and c).

If two such housing halves are located at the U edges (31), i.e. joined together at the dividing line (32), a complete pump housing is obtained. The paddle wheel shown in FIGS. 4 and 5 is then surrounded on all sides by the two housing halves (10 ').

Figure 4 shows the side view of a paddle wheel (11). Such a paddle wheel would fit a housing half (10 ') in FIG. 2. The three concentrically arranged blade rings (23, 23 ', 23'') are shown incompletely for the sake of simplicity. Each blade ring consists of long blade cells (16a) and short blade cells (16b), which are arranged alternately. The depth of the long blade cells (16a) corresponds to the width of the associated side channel at its beginning and the short blade cells (16b) correspond to the width of the associated side channel at its end. At the beginning of a side channel, the long and short blade cells are therefore effective in their entire length. At the end of a side channel, all blade cells are effective in the length of a short blade cell. The volume of the blade cells of the different blade rings preferably decreases gradually from the inside to the outside, to the same extent as the volume (or the cross section) of the side channel belonging to each blade ring. Slip rings (21, 21 *) are fastened to the lateral sealing surfaces (19 ') between the blade ring steps of the blade wheel (11). The slide rings (21, 21 ') are preferably fastened in ring grooves which are incorporated in the lateral sealing surfaces (19') of the impeller. As in the case of the sliding rings of the housing halves (10 ¹ ), the sliding rings of the paddle wheel (11) also rise only slightly above the sealing surfaces (19 ') of the paddle wheel (11). The slide rings (21, 21 ') on the paddle wheel (11) correspond in their radial position to the slide rings (20, 20') in the housing halves (10 '), so that the slide ring lies on the slide ring.

The slide rings in the housing and on the paddle wheel preferably consist of the materials mentioned above in the description. They are advantageously fastened in appropriate ring grooves by gluing and pressing. A so-called reaction adhesive for metal and ceramic is preferably used for this purpose. A mixture of approximately equal parts of carbon powder and reaction adhesive is advantageous. The adhesive is advantageously an epoxy resin, a mixture of epoxy resin and acid anhydride, a cyanoacrylate adhesive, methacrylate adhesive, polyisocyanate and / or silicone resin adhesive. The parts to be joined are coated with the adhesive or adhesive mixture, the parts pressed together and, depending on the size of the parts, allowed to air dry for 10-20 hours. The curing process is then continued at 150-180 ° C. for 4-10 hours. Adhesives of the type mentioned are also approved for machines used in the food industry. In any case, the adhesive connection should withstand temperatures up to 160 °.

The material of the slide rings has high abrasion resistance, but at the same time also has sufficient lubricity and high resistance to aggressive media.

The final machining of the slide rings takes place in the glued-in and pressed-in state by machining. The above-mentioned carbonaceous materials are particularly suitable for such machining processes.

The use of slide rings also enables a further reduction in the sealing gap between the impeller (11) and the housing (10 '). The width of this sealing gap is approximately 0.02 - 0.05 mm. It is therefore approximately a power of ten smaller than the sealing gap width of a conventional side channel pump. The slide rings preferably rise about 0.05-0.2 mm above the sealing surfaces (19, 19 ') in which they are embedded.

Figure 5 shows the paddle wheel of Figure 4 in cross section. The fit of the slide rings (21, 21 ') in the lateral sealing surfaces (19') of each blade ring (23,23 ') is particularly clearly expressed in this figure. In the embodiment shown here, a short blade cell (16b) is arranged opposite a long blade cell (16a). As already mentioned above, short and long blade cells alternate within a blade ring. Bucket rings arranged opposite one another at the same level are therefore of the same type. The paddle wheel of Figure 5 together with two housing halves (10 ') of Figures 2 and 3 results in a three-stage side channel pump with two separate media flows, which only come together again in the outlet channel (27) (Figures 2 and 3). The union can also take place in the last side channel stage (15c) if the central web (39) of the third and last stage of the paddle wheel is not allowed to extend to the outer contour (18) of the third and last side channel (15c).

In the case of the mirror-symmetrical impeller of FIG. 5, which can be operated in both directions of rotation, the axial loads during operation cancel each other out. There is a so-called floating, axially balanced bearing of the paddle wheel. It is set to run without contact with the two housing disks (10 '). To compensate for temporary pressure differences between the flow on one and the other side of the impeller, there may be small bores (38) running in the axial direction in the respective vane rings (23, 23 ', 23''), which ά. ■ = media flows on both sides of the paddle wheel (11). ^• find.

As already mentioned above, FIGS. 6-13 show the housing halves (10 ') of a two-stage side channel pump according to the invention. The associated paddle wheel (11) is not shown. It corresponds to the blade wheel shown in FIGS. 4 and 5 with the only difference that it has only two blade rings (23, 23 ') or (23', 23 ''). The design according to the invention of the inputs and outputs of the side channels and the transfer channel or the transfer chamber, which represents the connection between two side channels, is described with reference to FIGS

FIG. 6 shows a view of the outside of a housing half (10 ') according to the invention. A view of the inside of this housing half is shown in Figure 9. FIGS. 7, 8 and 10-12 show different cross sections of this housing half.

In Figure 6 is the inlet channel through which to be pumped

Medium enters the first side channel of the pump with which

Reference numeral 25 denotes. The entrance opening into this

The channel is indicated by a hatched area. The widening of the outer wall of the inlet channel (25) perpendicular to the plane of the paper is indicated by the shortened circular arc adjoining the hatched area. The exit from this first side channel, which cannot be shown in FIG. 6, is the hatched area designated by the reference number (30). Through this exit the medium reaches the side of the housing half (10 ') facing the viewer of FIG. 6 into the transition chamber (33). This chamber (33) is enclosed on all sides by the radially extending side walls (35, 35 '), the wall (36) surrounding the axis opening and the outer peripheral wall (34). The bottom of this

Chamber forms the outer side wall (22) of the housing half (10 '). In Figure 6 the chamber (33) is in the open state, i.e. shown without lid. The medium thus enters the chamber (33) from the opening (30) and leaves this chamber again through the entrance (29) of the second side channel.

Again, the opening of this second side channel is shown as a hatched area. The medium can also pass from the opening (30) into the opening (29) of the second side channel through a closed channel (28) ^" . This channel (28) is indicated by broken lines in FIG. 6.

7 shows the first and second side channels (15a and b) and the outlet (30) from the end of the first side channel into the transition chamber (33). In addition, the sealing ring (20) in the lateral sealing surface (19) of the housing is shown in this figure.

The sectional view of FIG. (8) along line CD of FIG. 6 goes through the outlet opening (27) of the second side channel (15b). This outlet opening cannot be shown in FIG. 6. It can be seen in FIG. 9 at the 90 ° mark on the circumference of the housing half. The division into degrees

Figure 9 is the same as in Figure 6. The section CD thus follows the line from 90 ^* to 270 °.

The two side channels (15a and b) with their inlet and outlet openings can be clearly seen in FIG.

The open side of the side channels facing the paddle wheel (not shown) also faces the viewer here. The reference numeral 26 designates the mouth region of the inlet channel (25). The funnel-shaped expansion of this mouth area (26) to the outside is indicated by the thinly hatched area. After the medium has entered through the mouth (26) into the side channel (15a), it travels approximately 270 ° and leaves this side channel at its end through the opening (30). It flows through the mouth (29) into the second side channel (15b) through the transfer chamber (33) or the transfer channel (28) shown in FIG.

Here, too, the funnel-shaped entrance area (29) is indicated by a hatched area,

This second side channel leaves the medium at the outlet opening (27). The reference number (37) indicates an extension of the inner contour (17) of the side channel (15b) in the end area. This is one of the different ways to vary the standard pressure of a particular pump design for a particular speed of a paddle wheel. Due to the side channel expansion (37) in the end area of the side channel, there is no further pressure increase. Depending on how long you choose this extension, you can set the pressure higher or lower. It can also be clearly seen from FIG. 9 that the first side channel (15a) is wider overall than the second side channel (15b) and that both side channels each taper towards the end. With the degree of tapering and the ratio of the cross-sectional area of the side channel to the depth of the blade ring, the delivery volume and the delivery pressure can be varied within wide limits for a given speed of the blade wheel.

The sectional view of Figure 10 along the line EF of Figure 6 (i.e. along the line of about 295 ° / 112 °, 30 ') shows again the arrangement of the side channels (15a and b) to each other and the enlarged mouth (26) of the Entry channel (25). This enlarged mouth region (26) is indicated in FIG. 10 by the hatched area (26). This surface should therefore be an individual perspective element that has been integrated into the sectional view in FIG. 10. Figure 12 shows something similar.

Here, too, the hatched area (29) is intended to symbolize the expanded region of the mouth of the transition channel into the second side channel (15b).

FIG. 11 shows a sectional view of a section of the housing half (10 ') of FIGS. 6 and 9. It is the section with the mouth (29) of the transfer channel into the second side channel (15b). The section line L-M is designated in FIG. 6.

Figure 13 shows the housing half (10 ") of Figures 6 and 9 in a spatial representation. In the area of the mouth (26) of the inlet channel (25) and the transition channel (28) or the transition chamber (33) there is an angle of approximately 90 ° Extending section has been removed from the drawing in order to be able to better show the details of the design of the inlet and transition openings. In the area designated by the reference number (26) one can see the deepening and widening of the entrance of the inlet channel (25) in the first side channel (15a) In the area of the white marking (30) this first side channel ends and leads there into the transfer channel (28) or the transfer chamber (33), from where the medium flows through the enlarged and deepened one The medium leaves this second side channel and the pump at the outlet (27). Two housing halves of the type shown can be connected to the one shown in FIG faces facing the traditional costume are placed on top of one another and screwed together. They then form a closed pump housing, in which of course a corresponding paddle wheel (11) is arranged. Threaded holes (40) can be provided in the housing edge for the screw connection. The pump according to the invention is extremely powerful and easily variable, so that it can be quickly adapted to all needs.

^* REFERENCE SIGN LIST

, 6 - housing washers, 8 - housing cover - housing ring - housing '- housing half (disc-shaped) - paddle wheel - drive shaft - suction opening - outlet opening ^{■ "} - * - side channel (15a, b, c) - bucket cells a - long bucket cells b - short bucket cells - Inner contour of the side channel - outer contour of the side channel - side sealing surfaces on the housing. '- u - sealing surfaces on the impeller, 20' - slide ring on the housing, 21 '- slide ring on the paddle wheel - outer side wall of the housing, 23', 23 "- blade ring - ventilation hole - Inlet channel - mouth of the inlet channel in the side channel - outlet channel - overflow channel, 29 '- mouth of the overflow channel in the side channel, 30' - start of the overflow and end of the side channel -. Peripheral edge of a housing half - parting plane of the housing halves Continued reference symbol list

33 - transfer chamber

34 - peripheral wall of the pressure chamber 35,35 '- radial wall of the pressure chamber

36 - axis peripheral wall d. Pressure chamber

37 - Extension of the side channel

38 - pressure equalization holes

39 - center web of the paddle wheel

40 - threaded hole

Claims

P a t e n t a n s r u c h e

1. side channel pump with a housing that can be assembled from two shells, disc-shaped impeller wheel arranged therein with at least two impeller rings, which are arranged on both sides of the disc plane of the impeller and with an associated drive shaft,

two flow channels, which start from a common suction opening in the housing and lead to a common outlet opening in the housing via at least one side channel step formed in the housing and associated blade cells of a blade ring, the two flow channels through the disc of the blade wheel which extends through to the circumference of the blade wheel are separated, and being

the blade cells of each blade ring are alternately long and short in the radial direction,

each side channel has an outer contour which is concentric to the blade wheel axis and a spiral-shaped inner contour, the radius vector of the spiral-shaped inner contour at the suction opening corresponding to the distance of the bottom of a long blade cell from the shaft and at the outlet opening to the distance of the bottom of a short blade cell from the shaft,

and being in the case of a multi-stage side channel pump. at least one transition channel is formed in each of the two side walls of the housing and connects the end of a side channel step to the beginning of the step that follows in the radial direction. characterized in that

sliding rings (20, 21 ') are arranged on the paddle wheel (11) and / or the housing shells (10) in the region of the lateral sealing surfaces (19, 19'),

and that the inlet channel (25) and, in the case of multiple stages, the transition channels (28) at an acute angle to the parting plane (32) of the housing shells (10) and tangential to the (imaginary) side channel center line in the corresponding side channel (15 a, b , c) open out, the mouth (26) of the inlet channel (25) being widened like a funnel towards the outside of the housing shells (10) and the mouth (29) of the transfer channel (28) merging continuously into the side channel.

Side channel pump according to claim 1, characterized in that the inner contour (17) of the

Side channel is designed according to an Archimedean spiral.

3. Side channel pump according to claim 1 or 2, characterized in that the inlet channel (25) in the vicinity of the axis coming from the outside through the side wall (22) of the housing shells (10).

4. Side channel pump according to one of the preceding claims, characterized in that each transfer channel (28) through a on the outside (22) of the housing shells (10) arranged separate chamber (33).

5. Side channel pump according to one of claims 1 to 4, da¬ characterized in that the inlet and outlet channels (25 and 27), the transfer channels (28) and their beginnings (30) and mouths (26, 29) in streams direction are designed so that a continuous flow with minimal resistance is ensured. 6. Side channel pump according to one of the preceding Ansprü¬ che, characterized in that the sliding rings (20, 21) are made on carbon graphite or polytetrafluoroethylene (PTFE) basis.

7. side channel pump according to claim 6, characterized in that as a sliding ring material with synthetic resin impregnated carbon graphite, an impregnated with antimony carbon graphite or a treated with a special impregnation approved for foodstuffs' carbon graphite or glass fiber reinforced PTFE or carbon reinforced PTFE is used.

8. side channel pump according to one of claims 1 to 5, da¬ characterized in that as a sliding ring material special chrome cast, special chrome molybdenum cast, stellitized CrNiMo steel, Hastelloy B-2 (2.4617), Hastelloy C (2.4619 or 2.4819), cobalt-bound Tungsten carbide, nickel-bonded tungsten carbide, Si-SiC (reaction-bonded silicon carbide), SiC (silicon carbide sintered without pressure), C-SiC (surface-siliconized carbon), C-SiC-Si (silicon-impregnated carbon), aluminum oxide 97.5%, aluminum oxide 99.5% is used.

9. Side channel pump according to one of the preceding claims, characterized in that the slide rings (22, 21) are glued or pressed into annular grooves in the region of the lateral sealing surfaces (19, 19 ').

10. Side channel pump according to claim 9, characterized in that the slide rings (20, 21) rise a little above the surfaces (19) in which they are embedded.