Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D23/00—Other rotary non-positive-displacement pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D23/00—Other rotary non-positive-displacement pumps
  • F04D23/008—Regenerative pumps

Definitions

• the invention relates to a side channel compressor, having an inlet opening for gas and an outlet opening for compressed gas and a side channel which connects the inlet with the outlet opening in terms of flow, the cross section of the side channel between the inlet opening and the outlet opening being reduced.
• Such a side channel compressor is known from DE 197 08 952 AI.
• the cross section of the side channel tapers continuously from the inlet opening to the outlet opening.
• the taper is intended to increase the efficiency of the side channel blower by resulting in a uniform pressure increase and an increase in the volume flow in the side channel.
• the cross section of the side channel is rectangular, but with rounded corners.
• the object of the invention is to achieve a side channel compressor with increased efficiency.
• a side channel compressor of the type mentioned in that the side channel has at least one section in which it has a cross section in the form of an ellipse half and in which the maximum depth of the channel continuously decreases in the direction of the outlet opening.
• the flow conditions in the side channel are optimized by making the transitions of the wall regions delimiting the cross section very soft, so that transitions in the actual sense are missing. This is achieved through the elliptical shape of the channel.
• the gas flows from the blades of the compressor with an axial velocity component, based on the blade axis, into the side channel and is deflected in the latter without extreme losses being able to occur. This leads to a higher volume flow and a higher compressor output. Thanks to the bevels associated with this, the elliptical design leads to a better producibility of the channel using sand or die casting processes.
• the section of the rare channel with an elliptical cross section can extend over the entire length of the side channel or even only over a part. At the latest, the section with an elliptical cross section should begin about half the flow path between the inlet opening and the outlet opening. In this area, the gas to be compressed already has one experience noticeable compression, to which the cross section should be adapted by reducing it
• the section with an elliptical cross section should end in the area of the outlet opening, where the highest compression is also present
• the optimal performance of the compressor can only be achieved by matching the reduction in the cross section of the side channel to the type of gas and the performance of the compressor, in particular its speed.
• the cross section is extreme greatly or insufficiently reduced since the gas flow is blocked in the first case and the compressibility of the gas is not fully utilized in the second case
• the cross-sectional area of the side channel in the section with an elliptical cross section is adapted to the ratio of the increase in density of the gas in accordance with the preferred embodiment, by reducing the cross-sectional area accordingly.
• An optimal reduction in the cross-sectional area results when assuming an approximately adiabatic isentropic compression of the gas to be compressed, the cross-sectional area being reduced in accordance with the decreasing gas volume
• index 1 denotes the specific sizes at the inlet and index 2 the specific sizes at the outlet of the side channel
• the formulas above can be used to determine the optimal cross-sectional areas at any point on the channel.
• the optimization of the course of the tapering of the cross-sectional area over the length of the side channel, assuming adiabatic isentropic compression, is not necessarily limited to the elliptical channel cross-sectional shape. Rather, this corresponding reduction in the cross section can also lead to an optimization of the efficiency in other channel shapes.
• a further embodiment of the invention provides that the side channel has a semicircular cross section in front of the section with an elliptical cross section. This semicircular cross section then merges smoothly into an increasingly flat ellipse, with the large axis of the ellipse preferably lying essentially on the flat surface of the cover of the side channel compressor which has the side channel.
• the large axis of the ellipse lies slightly inside the cover of the side channel compressor, which has the side channel.
• the width of the side channel should preferably remain constant over its entire length, so that the reduction in cross section takes place exclusively over the reduced depth, but with an adapted elliptical shape.
• the side channel is horseshoe-shaped in a side view, so that a large side channel length results. Extensions at the ends of the channel form the inlet or outlet opening.
• the side channel compressor according to the invention can be designed in one or more stages, the cross-sectional area of the inlet opening of a subsequent stage preferably corresponding to the cross-sectional area of the outlet opening of the immediately preceding stage.
• the aim is to prevent the gas in the channel from undergoing a change in state between successive stages
• the individual stages are preferably all provided with a side channel as previously defined, that is to say with a continuously decreasing cross-sectional area between the inlet opening and the outlet opening. Since the pressure curve in a multi-stage compressor is different from that in a single-stage compressor, the reduction must of course be made the cross-sectional area should be adapted to this effect. With the same increase in pressure between the inlet and outlet of a two-stage and a one-stage compressor, only half of the duct tapering compared to that of the single-stage compressor would be necessary per stage in the two-stage compressor
• FIG. 1 shows a longitudinal section through a two-stage side channel compressor according to the invention
• FIG. 2 shows a side view of a cover shown in FIG. 1 with a side channel
• FIG. 4 shows a side view of a slightly modified cover with a modified side channel
• Figure 5 successive cross-sections of the side channel along the section lines AI, and shown in Figure 4 Figure 6 shows different efficiency curves at different speeds of side channel blowers without, with 15% cross-sectional taper and with 30% cross-sectional taper.
• a drive motor 10 In the side channel blower shown in FIG. 1, a drive motor 10, a first stage 12 and a second stage 14 are integrated in one structural unit. With 16 a housing is designated.
• Impellers 20, 22 of stages 12 and 14 are fastened to a drive shaft, which in turn is set in rotation by the drive motor 10.
• Housing 16 is screwed, has a side channel 32 of the first stage.
• a second housing cover 26 which has a side channel 28, is connected to the housing 16.
• the first stage 12 has inlet openings and
• Stage is through a channel, not shown, in the housing with the inlet opening of the second
• Inlet openings of the second stage are designed so that there is no change in cross-section between the first and second stages in the region of the channel.
• the housing cover 30 is shown in FIG. 2 alone.
• the side channel 32 formed therein is essentially horseshoe-shaped and has an annular section extending over 270 ° (extending from section line A to section line E).
• An inlet opening 42 upstream of the section line A extends over approximately 15 ° and forms a kind of extension of the side channel 32.
• a continuation-like outlet opening 44 is likewise provided downstream of the section line E.
• the side channel 32 has the same width from the section line A to the section line E, as can also be seen from the section sequence in FIG. 3, which only shows the side channel itself.
• the side channel initially has a semicircular cross section at the section line A, the center of the semicircle even lying somewhat below the flat surface 46 of the cover 30, from which the side channel 32 extends into the interior of the cover.
• the distance 46 from the center M is given as 1 mm.
• the section of the side channel 32 from Section line A to section line E forms a section with an elliptical side channel cross section.
• the cross section of the side channel 32 changes from a semicircle on section line A to an ellipse with ever decreasing depth. The depth is shown on section line B with hl, on section line C with h2, on section line D with h3 and on section line E with h4.
• the ellipse half, which defines the side channel, is compressed, so to speak, with increasing length of the flow path
• the cross-sectional area is adapted to the specific volume of the gas to be compressed, which is continuously reduced on the flow path, assuming an adiabatic isentropic change in state. This optimizes the efficiency of the side channel compressor
• the large axis of the ellipse also lies within the cover by about 1 mm
• the cross section of the side channel 32 which changes continuously and continuously from a semicircle to an increasingly flat ellipse, is distinguished by excellent flow conditions in the side channel 32, since only small flow losses occur.
• the efficiency of the side channel compressor is also so high because, as mentioned, the cross-sectional profile of the change in state of the compressed gas is adapted.
• FIGS. 4 and 5 A slightly modified housing cover 130 is shown in FIGS. 4 and 5, in which the side channel 132 has a slightly different inlet and outlet area.
• the inlet area extends over 15 ° to 50 °, as does the outlet area.
• Numeral 142 designates the first stage inlet port and 144 the first stage outlet port leading to the second stage inlet port
• the second stage 14 has a side channel which is also tapered over its entire length. This side channel also begins with a semicircular cross section, but this cross section has a surface which corresponds to the surface of the side channel at the outlet opening 44 with the elliptical cross section second stage then changes continuously to an increasingly flat ellipse, as shown in FIGS. 2 to 5
• FIG. 6 shows the increase in efficiency which can be achieved by reducing the side channel cross section.
• a side channel compressor which is designated by "series" has a semicircular cross section without tapering to
• On modified side channel blower according to the invention with an elliptical cross-section has a cross-sectional reduction of 15% between the inlet opening and the outlet opening and a further compressor a cross-sectional reduction of 30% is dependent on the speed of rotation
• a cross-sectional reduction of, for example, 15% at different speeds cannot achieve an enormous increase in efficiency Rather, the reduction in cross-section is to be adapted to the change in the state of the gas, which in turn is dependent on the geometric conditions in the side channel and in the impeller as well as on the volume flow and thus on the speed. It may well be that at certain speeds and certain geometries of the impeller together Blades must have significantly smaller or significantly higher cross-sectional reductions in order to achieve an optimal increase in

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Compressor (AREA)
• Motor Or Generator Cooling System (AREA)
• Massaging Devices (AREA)
• Magnetic Resonance Imaging Apparatus (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=7902649

Family Applications (1)

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Family Cites Families (13)

• 1999
  • 1999-03-26 DE DE19913950A patent/DE19913950A1/de not_active Withdrawn
• 2000
  • 2000-03-24 KR KR1020017012119A patent/KR100637090B1/ko not_active Expired - Fee Related
  • 2000-03-24 DE DE50003108T patent/DE50003108D1/de not_active Expired - Fee Related
  • 2000-03-24 AT AT00920569T patent/ATE246316T1/de not_active IP Right Cessation
  • 2000-03-24 EP EP00920569A patent/EP1165965B1/fr not_active Expired - Lifetime
  • 2000-03-24 DK DK00920569T patent/DK1165965T3/da active
  • 2000-03-24 ES ES00920569T patent/ES2203451T3/es not_active Expired - Lifetime
  • 2000-03-24 CN CN00805576A patent/CN1119531C/zh not_active Expired - Fee Related
  • 2000-03-24 WO PCT/EP2000/002624 patent/WO2000058629A1/fr not_active Ceased
  • 2000-03-24 AU AU41098/00A patent/AU763252B2/en not_active Ceased
  • 2000-03-24 JP JP2000608093A patent/JP2002540350A/ja active Pending
  • 2000-03-26 US US09/937,393 patent/US6779968B1/en not_active Expired - Fee Related

Non-Patent Citations (1)

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