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
  • F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
  • F04D15/0066—Control, e.g. regulation, of pumps, pumping installations or systems by changing the speed, e.g. of the driving engine
• • 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
  • F04D29/18—Rotors
  • F04D29/22—Rotors specially for centrifugal pumps
  • F04D29/2238—Special flow patterns
  • F04D29/225—Channel wheels, e.g. one blade or one flow channel
• • 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
  • F04D29/58—Cooling; Heating; Diminishing heat transfer
  • F04D29/586—Cooling; Heating; Diminishing heat transfer specially adapted for liquid pumps
  • F04D29/588—Cooling; Heating; Diminishing heat transfer specially adapted for liquid pumps cooling or heating the machine

Definitions

• the invention relates to a feed pump with a variable-speed drive, wherein the feed pump as a single-stage centrifugal pump with in a impeller space of a pump housing (1) rotatably mounted radial wheel (2) centrifugal design for conveying a fluid between a pump inlet (4) and a pump outlet (13) is, the radial wheel (2) is connected to a up to the five-digit range of revolutions per minute variable speed drive motor, the radial wheel (2) is centrally flowed, with delivery channels (3) is provided and with an outer diameter up to 55 mm at Has delivery heights up to 300 m.
• Such systems require a precise, constant, freely adjustable and pulsation-free volume flow of liquid substances.
• positive displacement pumps in the form of micro-toothed ring and gear pumps as well as in the form of diaphragm and piston pumps are used.
• Disadvantage of such positive displacement pumps are the lack of reliability due to friction between the relatively moving, sealed components and their pulsating flow. A related maintenance and the cost of wear and tear Parts as well as their change hinder rapid research and development and interfere with a production process sensitive.
• WO 2005/052365 A2 discloses a centrifugal pump in the form of a canned motor pump for circulating supercritical hydrocarbons.
• the drive motor has a split tube made of PEEK 1 within which a rotor protected by a stainless steel coating is arranged. Ceramic bearings of the pump shaft and the drive rotor are lubricated by a partial flow of the pumped liquid taken from the pump housing.
• the open-formed impeller has a diameter between see 1 and 2 inches and the rotor driving the rotor of the roller-mounted DC motor has a diameter between 1, 5 and 2 inches.
• the single-stage pumping device with the open impeller should reach maximum speeds of up to 60,000 rpm.
• Suction nozzle, discharge nozzle and a type of spiral space downstream of the impeller are arranged in an outer pump housing part, while an inner pump housing part has the cantilevered impeller and a mounting for a variable speed DC canned motor as a drive motor.
• a disadvantage of this canned motor design is the large number of gaps, which greatly hinder the cleaning of the pump due to the complex flow guidance between pump and canned motor. Since part of the pumped liquid continuously flows through the motor and its gap, the frictional heat of the roller bearings and the heat loss of the canned motor cause a high heat input into the pumped liquid. As a result, this pump can only be operated in close proximity to an undefined optimum operating point. In a partial load operation of this pump, an inadmissibly high heat input would take place very quickly. This would in addition to damage to the fluid also a failure of the pump due to cavitation or dry running result.
• the invention is based on the problem, for the promotion and dosage of liquid substances in the milliliter range of chemical, pharmaceutical and / or cosmetic components to develop a pump unit, the flow rate pulsation-free and precisely adjustable over a wide range for different media is variable with different characteristics and for quick product changes the pump is easy to clean.
• a metering pump in the form of a centrifugal centrifugal centrifugal design is realized. This is designed as a feed pump for use in a process plant for a nominal operation in the form of a permanent centrifugal pump partial load operation with flow rates in the range of 0 ml / min to 7000 ml / min, the rated operation by a centrifugal pump part-load specific speed nq T L ⁇ 0.05 ⁇ 10 (1 / min) is characterized and wherein the impeller space is provided at the periphery with one or more, acute-angled or tangential to Radialradaußen preparer arranged Pumpenauslasskanälen.
• this centrifugal pump is designed for extreme part-load operation, which promotes small amounts without pulsation.
• the feed pump preferably has a centrifugal pump partial load-specific speed nq T L ⁇ 0.05 ⁇ 3 (1 / min).
• the design of the feed pump for a centrifugal pump partial load operating range nq - TL has proven ⁇ 2.5.
• the outer diameter of the radial wheel (2) can be up to a maximum of 70 mm.
• the pump housing with a radial wheel arranged therein preferably has a residual volume of less than 30 milliliters. This has the significant advantage of easy flushing of the feed pump. And as a result of the small residual volume and the minimum number of slots, only a small loss of product occurs during a cleaning or flushing of a fluid to be delivered in the feed pump. Furthermore, an inner diameter of the impeller space is formed at most 4% larger than an outer diameter of the radial wheel. And by means of a reduction of the impeller space surrounding the radial wheel takes place at the Pumpenauslasskanal an increase in a pending there pitotast. there the inlet openings of one or more Pumpenauslasskanälen are formed in the form of pitot tubes or pitot tube-like.
• this is provided with a tempering device, preferably for a nominal operation with a centrifugal pump partial-speed specific speed nq T L ⁇ 0.05 ⁇ 1 (1 / min).
• a seal is arranged between the impeller space and the radial wheel and / or its shaft.
• a hermetically sealed, magnetically coupled drive transmits a torque to the radial wheel.
• the tempering and / or on a bearing housing a bearing for the shaft is arranged.
• the feed pump may be formed as a block aggregate with flanged engine.
• the feed pump is characterized by a constant travel operation or a metering operation.
• Fig. 1 is a feed pump in longitudinal section
• Fig. 2 is a perspective view of the pump unit
• Fig. 3 is a perspective view of an impeller
• Fig. 4 is an impeller in section
• FIG. 5 shows a cross section through the feed pump and FIG. 6 shows the position of the feed pump in a nq diagram
• a feed pump is shown in a single-stage design.
• a radial wheel 2 centrifugal type is arranged to rotate.
• the radial wheel 2 has delivery channels 3 and is centrally through a pump inlet 4 flows.
• the radial wheel 2 is connected to transmit power to a variable speed drive 5 and has an outer diameter DL A , which may be up to 70 mm.
• the radial wheel rotates in an impeller space 6 whose inner diameter D L RI is designed to be at most 4% larger than the outer diameter DLA of the radial wheel 2.
• the pump housing 1 is provided with a tempering device 7, which is integrated in this embodiment in the pump housing.
• Fridges 7.1 to 7.3 surround the impeller space 6 and also adjacent to the pump housing 1 seal housing 8.
• Within the seal housing 8 is arranged as a kind of shaft seal a seal 9, which is shown in the embodiment as a lip seal.
• the seal 9 can also be designed as a mechanical seal.
• the tempering 7.1 to 7.3 are acted upon by external means.
• the area of the pump inlet 4 is defined by a contact surface 12 located in the immediate vicinity of the pump interior, against which a line to be connected for a delivery fluid bears sealingly.
• An analogous training is on the - here below the drawing plane, only partially visible as a semicircle - pump outlet 13 is present.
• Fig. 2 the perspective view of the unitized pump, the pump inlet 4 and the pump outlet 13 can be seen.
• the tempering device 7 is integrated in the pump housing 1 and pump inlet 4 and pump outlet 13 are passed through the tempering 7 to the impeller space.
• External tempering means for example, coolants
• External tempering means for example, coolants
• Pump unit and drive motor 5 are combined to form a structural unit and held in a support member 16.
• the support element 16 provides the prerequisite for the modular design or installation in an existing system.
• Fig. 3 shows a perspective view of a radial wheel 2.
• the radial wheel 2 is disc-shaped and provided in this example with a hub 2.1.
• Within the hub 2.1 is a force-transmitted connection with the shaft 10, not shown here of the drive 5.
• Within the radial wheel 2 conveyor channels 3 are arranged.
• a plurality of conveying recesses 18 are arranged on the impeller periphery 17, which are designed in the form of blind holes. With the help of these wells the pressure digit of the centrifugal impeller is improved.
• the pressure and suction-side cover disks 19, 20 have a plurality of radially extending feed grooves 21.
• the conveyor grooves 21 also improve the pressure digit of a built-in impeller 6 in accordance with FIG. 1 impeller.
• the impeller in the axial direction penetrating compensation bores 22 serve to equalize the pressure within the pump housing and at the same time as an assembly aid in making a connection to the drive.
• the depth T of the conveying recesses 18 is selected as a function of the desired residual volume of a fully assembled pump.
• any other shape such as grooves, slots or the like, find application, with which in the range of the impeller outer diameter, an energy transfer is possible.
• Fig. 5 shows a cross section through the feed pump. Due to the generous temperature control room 7.2, which is in operative connection with the other temperature control room, a permanent extreme partial load operation is guaranteed.
• the pump outlet channel 13 may be designed as a simple bore or it may - as shown - be formed by a pitot tube-like insert 24 having an inlet opening 25. The latter allows for easy customization.
• a radial gap width which lies in the single-digit millimeter range, results between the outside diameter DL A of the radial wheel and the enveloping, surrounding diameter D LR I of the rotor wheel space 6.
• the radial gap between impeller and housing is in the range of 2 mm.
• the gap between the impeller and the housing is of an analogous order of magnitude.
• the peripheral component of the impeller simultaneously approaches the peripheral speed and in combination with an obliquely inclined, preferably tangential, impeller 2 disposed pump outlet 13 results for this centrifugal pump at the outlet opening a maximum possible back pressure.
• high delivery heads can be realized with a minimum residual volume within the pump housing.
• the non-contact arrangement of the impeller within the impeller space avoids sealingly abutting friction surfaces. This measure prevents the generation of mechanical frictional heat, prevents fretting wear and the resulting contamination of a pumped liquid with abraded particles, and improves the operational safety through significantly extended service lives. In addition, the cleanability counteracting sealing gaps are avoided.
• the nq values of centrifugal pumps are compared with those of the positive displacement pumps in a nq diagram in characteristic diagrams drawn with solid lines.
• the new delivery pump covers the area between these two opposing pump types with its characteristic diagram of the centrifugal pump partial-load-specific speed nq ⁇ L.

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=39651186

Family Applications (1)

Country Status (9)

Cited By (1)

Families Citing this family (5)

Family Cites Families (16)

• 2007
  • 2007-04-28 DE DE102007020218A patent/DE102007020218A1/de not_active Withdrawn
• 2008
  • 2008-04-08 WO PCT/EP2008/002767 patent/WO2008131846A1/de active Application Filing
  • 2008-04-08 EP EP08735086A patent/EP2142804A1/de not_active Withdrawn
  • 2008-04-08 AU AU2008243437A patent/AU2008243437A1/en not_active Abandoned
  • 2008-04-08 CN CN200880014126A patent/CN101680456A/zh active Pending
  • 2008-04-08 JP JP2010504488A patent/JP2010525223A/ja active Pending
  • 2008-04-25 TW TW097115162A patent/TW200916660A/zh unknown
• 2009
  • 2009-08-05 ZA ZA200905469A patent/ZA200905469B/xx unknown
  • 2009-10-28 US US12/607,683 patent/US20100111680A1/en not_active Abandoned

Non-Patent Citations (1)

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