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
  • F04D29/00—Details, component parts, or accessories
  • F04D29/08—Sealings
  • F04D29/16—Sealings between pressure and suction sides
  • F04D29/165—Sealings between pressure and suction sides especially adapted for liquid pumps
  • F04D29/167—Sealings between pressure and suction sides especially adapted for liquid pumps of a centrifugal flow wheel

Definitions

• the invention relates to a device for impeller sealing in centrifugal pumps for fluid media.
• the device serves to the construction of centrifugal pumps existing gap between the impeller and the
• Gap seal provided pump used.
• Centrifugal pumps of different designs are used for the transport of fluid media, in particular liquids in very large numbers.
• the pumps consist of one or more impellers arranged on a shaft, which, driven by a motor, move in a corresponding free space of a pump housing (also referred to as housing bore).
• a respective impeller generates a negative pressure at its impeller inlet side, at which the inflow for the fluid medium to be conveyed is located.
• the medium is entrained at or in the impeller and transported by this in the course of the rotational movement to the impeller outlet on the pressure side of the impeller.
• a gap between the impeller and the inner wall of the pump housing is essential. This is designed depending on the housing shape and impeller shape as axial or radial gap.
• DE 199 60 160 A1 describes a device for optimizing the gap width in centrifugal pumps. After the solution described, a bead is formed on the outer circumference of the free end of a pump impeller. This bead is guided when inserting the impeller in the pump housing behind a sealing collar, which is formed on a housing arranged in the split ring. As a result, a very small gap size is achieved.
• the sealing collar according to the solution is a rigid element, there is a risk that it may become if deposits form on it, runs into the impeller above the bead formed on the impeller. In addition, a mass transport from the pressure side to the suction side is not prevented by the remaining small gap, so that the risk of braid formation and finally the clogging of the gap is not eliminated.
• the arrangement is comparatively complicated and insofar not self-sealing, as that is expected to increase very quickly by an occurring at the elastic elements during operation of the pump abrasion of the already remaining minimum residual gap.
• the areas in which the springs are arranged not self-sealed.
• deposits may form on the springs and block them, so that they can no longer exert the pressure required for extensive gap sealing on the elements pressing against the rotor wheel.
• the risk of shrinkage of partially applied with larger surface areas on the impeller elastic elements is given in the corresponding contact surface, which also a disabling of the seal after a relatively low operating time of the pump is to be expected.
• the object of the invention is therefore to provide a device for impeller sealing in centrifugal pumps, through which in a very simple construction of the device, the mass transfer between the pressure side of the impeller of a centrifugal pump and the impeller inlet permanently reliably prevented, but still an unobstructed rotational movement of the wheels or in the pump housing is made possible.
• the device By means of the device to be created, in particular even when used in sewage pumps such mass transport and thus braid formation in the gap area are to be prevented.
• the device should allow both the factory equipment of pumps as well as be retrofitted.
• the device according to the invention can be used both in centrifugal pumps with an axial gap and in those with a radial gap, depending on the geometry of their elements and their structural arrangement in the pump, as already stated. Furthermore, both single-stage and multi-stage centrifugal pumps, that is centrifugal pumps with more than one impeller, factory or in the course of retrofitting can be equipped with the inventive device.
• a sealing ring is arranged between the pressure side and the suction side of the at least one impeller to solve the problem in the pump housing of the equipped or retrofitted centrifugal pump, which consists of a rigid pressure ring and one with the pressure ring connected annular elastic sealing lip consists. The sealing lip is connected in the region of its inner diameter with the pressure ring.
• the sealing lip is inclined against a formed on the peripheral contour in the region of the impeller inlet on the impeller sliding surface.
• the sealing ring formed as described above acts according to the invention held on the pump housing actuator.
• the sealing ring is positioned with respect to the sliding surface and at the same time its sealing lip in the protruding from the pressure ring and / or biased the diameter of the pressure ring portion biased against the sliding surface of the impeller.
• the sealing ring is thereby positioned and its sealing lip biased so that it rests with a radially outer end of the aforementioned area in the operation of the pump on the sliding surface.
• the adjustment to be made on the actuator may be such that the sealing lip abuts only slightly (very low bias) on the corresponding sliding surface of the impeller in the resting state of the pump and the concerns of the radially outer end of the sealing lip on the sliding surface during operation of the pump In addition, between its pressure side and the suction side existing pressure difference is ensured safe.
• the sealing device is designed so that due to the deformability of the projecting for this purpose in sufficient length of the pressure ring and / or him sufficient extent with respect to its diameter region of the sealing lip and the bias generated by means of the actuator in the sealing lip bias a permanent as well self-adjusting complete sealing of the gap is given.
• the sealing ring is adjusted by means of the actuator with regard to its position and the preloading of its sealing lip such that the radially outer end of the sealing lip just touched the wear ring with the lowest possible bias voltage.
• the sliding surface is part of a fixed in the region of the impeller inlet on the peripheral contour of the impeller rigid wear ring.
• the abovementioned wear ring can already be arranged on the impeller at the factory on a pump equipped with the device according to the invention or can be fastened in the course of a retrofit with appropriate reworking of the impeller.
• the wear ring is made of a particularly wear-resistant material such as stainless steel, ceramic or a special composite, or it is at least provided with a special wear protection coating.
• the wear-resistant sliding surface is preferably realized by applying a wear ring on the impeller in the impeller inlet.
• the sealing ring is, as already stated, realized by a rigid pressure ring and an elastic sealing lip connected to it, wherein the pressure ring also consists of a wear-resistant material, preferably metal.
• the sealing lip in the case of a metallic pressure ring, consists of an elastomer and is connected to the pressure ring by vulcanization.
• the invention can be advantageously further developed by the fact that in the elastomer for mechanical stabilization, a reinforcing material, preferably a metal mesh, is embedded.
• a reinforcing material preferably a metal mesh
• the geometry of the elastic, preferably made of an elastomer or rubber sealing lip is advantageously designed so that the thickness is reduced radially outward.
• the sealing lip due to the pressure difference existing between the pressure side and the impeller inlet on the suction side, it is nevertheless ensured that the sealing lip, at least during operation of the centrifugal pump, rests in a sliding manner and completely seals the gap against the sliding surface of the associated impeller.
• the gap seal due to the bias of the elastic sealing lip against the sliding surface is self-adjusting so far as the sealing lip, even if it gradually abrades in the course of operation, due to the given during operation pressure difference between the pressure and the suction side up to a certain Wear level is still sealing against the sliding surface when the pump is in operation.
• a complete sealing of the gap during operation of the pump by which an accumulation of solids and / or contained in the conveyed medium fibrous components in the gap region and thus clogging by braid formation is effectively prevented even when used in wastewater, even then still be given when the sealing lip is no longer applied to the sliding surface when the pump is switched off due to material wear.
• the bias in the elastic sealing lip of the sealing ring is achieved by suitable positioning of the sealing ring in the pump housing or in relation to the sliding surface, wherein the sealing ring is supported on a present in the interior of the pump housing abutment so that on its sealing lip a certain Pressure is exercised.
• the solution according to the invention may possibly also be realized by an already existing split ring fixed in the pump housing acting as an abutment, as is customary for setting a predetermined gap width in pumps of the prior art, after corresponding reworking according to the invention with a counterpart, a likewise retrofitted wear ring of the impeller or its sliding surface inclined sealing lip is connected by mechanical fastening or vulcanization.
• the actuator acting on the sealing ring is designed as an adjusting ring adjustable in the axial direction with respect to its position, which acts directly on the sealing ring.
• the sealing lip is in this embodiment at least during operation of the centrifugal pump, slidably disposed on a preferably orthogonal to the axial direction or pump axis outer surface of the wear ring, wherein the axial direction is given by the direction of the longitudinal extent of the one impeller or possibly more impellers driving motor shaft ,
• the position of the adjusting ring by means of two or more, with respect to the circumference of the adjusting ring approximately equally distributed arranged adjusting screws adjustable, which are each brought into engagement with a pump housing in the axial direction extending thread.
• the threads for the screws are preferably formed in threaded holes, which are passed in the axial direction through the pump housing.
• the threads for the screws of the actuator are each arranged in a part in the arranged on the outer circumference of the housing ring circular segment-shaped recesses and another part in corresponding to these recesses of the housing ring and together with these preferably each a full circle enclosing, annular recesses of the pump housing educated.
• the adjusting ring has an external thread and is brought into engagement with a correspondingly arranged internal thread of the pump housing. The axial position of the adjusting ring is thus adjustable within the centrifugal pump by rotating the adjusting ring in the internal thread of the pump housing.
• the device according to the invention according to an advantageous development of locking screws, by means of which the collar in the respective can be fixed for him set position and position.
• the device according to the invention is suitable for the original equipment of centrifugal pumps as well as their retrofitting. Therefore, the device according to an intended for retrofitting training is designed so that their respective elements are components of a kit, which is also attached to a drilling template or a jig for the correct position arrangement of the screws and optionally for the locking screws to be formed threaded holes.
• the invention will be explained in more detail below with reference to embodiments. In this case, the explained examples relate to variants which are suitable, in particular, for the conversion of pumps which were not previously provided with a corresponding device.
• Fig. 1 a corresponding to a possible embodiment of the device according to the invention with this retrofitted centrifugal pump
• Fig. 2 an enlarged section of the pump according to Fig. 1 with the
• FIG. 3a, 3b the according to the embodiment of FIG. 1 and FIG. 2 additionally inserted into the housing of the pump housing ring,
• Fig. 1 shows an example of a retrofitted with the device according to the invention centrifugal pump, the pump is shown for better illustration with an outbreak in the pump housing 1.
• the example shown relates to the conversion of a centrifugal pump, in which the impeller 2 is designed in the form of a channel wheel.
• This and the other explained in connection with the drawings embodiment relates to an embodiment in which connected to the pressure ring 7 and this together with the sealing ring forming annular elastic sealing lip 8 is biased by means of an acting on the sealing ring 9 and the sliding surface. 6 'is formed on a attached to the impeller 2 Schl constitutionring 6.
• the pump consists of the pump housing 1 in which the arranged on a motor shaft not shown impeller 2 or channel wheel during operation of the pump in the circumferential direction u moves.
• the motor also not shown here, is flange-mounted on the pump housing 1 on the right-hand side of the pump so that the motor shaft extends in the axial direction a.
• the gap to be sealed is formed, in which it is due to the design of the pump shown in the example is an axial gap. This gap is completely sealed by means of the, in the enlarged section of Fig. 2 again better illustrated inventive device against mass transfer between the pressure side 3 of the pump and the impeller inlet 5 on the suction side 4 of the pump.
• FIG. 2 shows an enlarged detail of the centrifugal pump which has been retrofitted or retrofitted with the device according to the invention for impeller sealing according to FIG. 1, in a sectional view.
• a shoulder has been formed by twisting on the outer contour of the impeller 2.
• highly wear-resistant wear ring 6 was attached and by means of several screws to the impeller 2.
• previously distributed on the circumference corresponding with the counterbores of the wear ring 6 corresponding threaded holes are introduced into the impeller 2.
• a preferably metallic housing ring 1 1 has been added to reduce the in this pump on the side of the impeller inlet 5 relatively large diameter of the housing bore addition, the training in Figs.
• the housing ring 1 1 has a plurality of annular recesses 12, which are each provided with a first part of a thread and, together with corresponding, incorporated in the pump housing 1 and provided with the associated second part of the thread recesses each include a full circle or circular cylinder.
• each set screws 10 are brought into engagement.
• the adjusting ring 9 in the axial direction a is movable.
• the adjusting screws 10 serve at the same time for fastening the housing ring 1 1 in the pump housing 1.
• adjusting ring 9 presses against the flexible portion 8 'of the sealing lip 8 of the adjusting ring 9 and the wear ring 6 arranged Sealing ring, wherein the pressing force with which the sealing lip 8 is pressed against the wear ring 6, is dependent on the adjustable by means of screws 10 position of the adjusting ring 9.
• the respectively set and adjustable if necessary position of the adjusting ring 9 is by means of an inner bore of the Set screws 10 guided and each brought with a threaded hole in the adjusting ring 9 engaged locking screws 15, which are presently designed as lag screws, fixed.
• the screw heads of the captive arranged locking screws 15 reach a shoulder of the inner bore of the respective screw 10 to the plant.
• the sealing ring consists of a rigid metallic pressure ring 7 to which the annular rubber sealing lip 8 is screwed in the example shown.
• a compound of the rigid pressure ring 7 with the sealing lip 8 by vulcanization is more advantageous.
• the sealing lip 8 is biased by the adjusting ring 9 so that it, as shown in the figure, with the pump off only with respect to its outer peripheral end 8 "of the pressure ring 7 superior flexible portion 8 'on the wear ring. 6
• the sealing lip 8 is pressed closer to the wear ring 6 with complete sealing of the axial gap due to the pressure difference between the pressure side 3 of the pump and the impeller inlet 5 of the suction side 4.
• the sealing lip 8 is only slidable with the outer end 8 "of the area 8 'on the wear ring 6, so that the rotational movement of the impeller 2 of the pump is still possible. Due to the applied to the sealing lip 8 bias remains while the sliding contact with the sliding surface 6 even with operationally occurring axial and / or radial vibrations of the impeller 2 always exist. It is thus a reliable despite possible vibrations, but also permanent, self-adjusting complete seal for the gap between the pump housing 1 and the suction side 4 of the impeller 2 and the impeller inlet 5 given.
• a centrifugal pump equipped with the device according to the invention as a wastewater pump As a result, a braid formation in the gap region and thus a subsequent blockage of the pump is reliably prevented.
• the adjusting ring 9 can be inserted directly into the pump housing 1 without additional housing ring 1 1.
• the screws 10 are guided by axially extending threaded holes in the pump housing 1.
• the embodiment without additional housing ring 1 1 course to give preference.
• the illustration of the embodiment shown in FIGS. 1 to 3 a or 3 b is intended to show that pumps already in use can also be retrofitted with the device according to the invention.
• Another embodiment of the device according to the invention is shown in Fig. 4 in a comparable with the Fig. 2 representation.
• the positioning of the adjusting ring 9 and thus of the sealing ring and the determination of the force acting on the sealing ring with pressure ring 7 and sealing lip 8 pressing force by means of an arranged on the end face of the adjusting ring 9 external thread 13.
• the axial position of the adjusting ring 9 in accordance with the requirements, that is concern of the radially outer end 8 "of the pressure ring 7 upstanding portion 8 'of the sealing lip 8 under the lowest possible bias on the wear ring 6, adjustable corresponding adjustment position of the adjusting ring 9 by means of the locking screws 15 (in the outer region of the adjusting ring are arranged one or more locking screws 15) which act as clamping screws and brace the flanks of the threads 13, 14 of the adjusting ring 9 and the pump housing 1 against each other between the pump housing 1 and the adjusting ring 9, an O-ring 16 made of rubber.
• the device according to the invention is achieved by the complete prevention of backflow, namely the return flow from the pressure side 3 to the suction side 4 on the impeller 2, and by the elimination of crossflow losses a significant increase in efficiency at appropriately equipped centrifugal pumps.
• Suction-side blockages are effectively prevented, in particular in sewage pumps with single or multi-channel impellers.
• the device is also characterized by a simple structure and a good retrofitting in already in use pumps.
• actuator for example, adjusting ring

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Priority Applications (5)

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Publications (1)

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ID=41017071

Family Applications (1)

Country Status (6)

Cited By (1)

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Citations (7)

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• 2008
  • 2008-05-15 DE DE102008001814A patent/DE102008001814A1/de not_active Withdrawn
• 2009
  • 2009-05-15 US US12/736,847 patent/US20110064566A1/en not_active Abandoned
  • 2009-05-15 DE DE112009001716T patent/DE112009001716A5/de not_active Withdrawn
  • 2009-05-15 EP EP09745466.4A patent/EP2304246B1/de active Active
  • 2009-05-15 CN CN2009801174652A patent/CN102027241B/zh not_active Expired - Fee Related
  • 2009-05-15 WO PCT/DE2009/050026 patent/WO2009138082A1/de active Application Filing
  • 2009-05-15 RU RU2010145437/06A patent/RU2474730C2/ru not_active IP Right Cessation

Patent Citations (7)

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