US20160348655A1 - Switchover device for a thick-matter pump - Google Patents

Switchover device for a thick-matter pump Download PDF

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Publication number
US20160348655A1
US20160348655A1 US14/901,296 US201414901296A US2016348655A1 US 20160348655 A1 US20160348655 A1 US 20160348655A1 US 201414901296 A US201414901296 A US 201414901296A US 2016348655 A1 US2016348655 A1 US 2016348655A1
Authority
US
United States
Prior art keywords
seal
support strip
pivot body
duct
elastic seal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US14/901,296
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English (en)
Inventor
Wolfgang Merten
Thorsten Koch
Joseph Schnittker
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Friedrich Wilhelm Schwing GmbH
Original Assignee
Friedrich Wilhelm Schwing GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Friedrich Wilhelm Schwing GmbH filed Critical Friedrich Wilhelm Schwing GmbH
Assigned to SCHWING GMBH reassignment SCHWING GMBH ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KOCH, THORSTEN, MERTEN, WOLFGANG, SCHNITTKER, Joseph
Publication of US20160348655A1 publication Critical patent/US20160348655A1/en
Abandoned legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B7/00—Piston machines or pumps characterised by having positively-driven valving
    • F04B7/0084—Component parts or details specially adapted therefor
    • F04B7/0088—Sealing arrangements between the distribution members and the housing
    • F04B7/0096—Sealing arrangements between the distribution members and the housing for pipe-type distribution members
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B15/00—Pumps adapted to handle specific fluids, e.g. by selection of specific materials for pumps or pump parts
    • F04B15/02—Pumps adapted to handle specific fluids, e.g. by selection of specific materials for pumps or pump parts the fluids being viscous or non-homogeneous
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B15/00—Pumps adapted to handle specific fluids, e.g. by selection of specific materials for pumps or pump parts
    • F04B15/02—Pumps adapted to handle specific fluids, e.g. by selection of specific materials for pumps or pump parts the fluids being viscous or non-homogeneous
    • F04B15/023—Pumps adapted to handle specific fluids, e.g. by selection of specific materials for pumps or pump parts the fluids being viscous or non-homogeneous supply of fluid to the pump by gravity through a hopper, e.g. without intake valve

Definitions

  • the invention relates to a switchover device for a thick-matter pump as well as to the use of a support strip in such a switchover device and to the use of a pivot body of such a switchover device.
  • a switchover device for thick-matter pumps can be configured, for example, as a transfer tube of a concrete pump. With such a switchover device, concrete is pressed at high pressure by means of two delivery cylinders via the transfer tube into a concrete delivery tube.
  • the pressure in the transfer tube of a concrete pump which may pump concrete by several hundreds of meters up onto building structures such as bridges or skyscrapers ranges at up to 160 bar for concrete pumps of the present generation.
  • pump pressures of 300 bar will be needed in future which will expose the seals of the delivery system to extreme strains and stresses.
  • a switchover device of this type With a switchover device of this type, the flow of concrete and/or thick-matter from a pre-fill vessel is pressed into a sucking delivery cylinder and from a pumping delivery cylinder into the delivery line.
  • the inlet and the outlet of the pivot body swinging to and fro in the housing at the cycle of the piston strokes are connected to each other through a passage duct in the pivot body.
  • This switchover technique puts high demands on the seals of the switchover device, particularly in order to avoid that the concrete, and particularly the water contained therein, is pressed from the passage duct of the pivot body into the pre-fill vessel.
  • the water contained in the concrete has the property of improving fluidity and thus transportability of concrete in the delivery line.
  • too dry concrete leads to clogging in the delivery line and may entail costly repair measures if concrete hardens in the deliver line.
  • a rubber seal made of hard rubber is usually laid into the seal chambers of the pivot body, said rubber seal pressing the pivot body against the two opposite sides of the housing of the switchover device.
  • a hard metal ring is inserted in addition to the rubber seal so that the rubber seal is not directly moved to and fro at the housing wall due to the pivoting motions of the pivot body, but the rubber seal presses the hard metal ring to the housing sides.
  • a metal support ring of this type is costly in manufacture and needs to be produced with utmost precision, in particular for a kidney-shaped seal, in order to fulfill the set task. Moreover, such a support ring does not have the elasticity required to sufficiently adapt itself to the circumferential shape of the seal chamber.
  • the present invention achieves this object by way of a switchover device for a thick-matter pump in accordance with claim 1 .
  • the present invention proposes to arrange a support strip around the elastic seal and/or the rubber seal within the seal chamber of the pivot body, said support strip supporting the elastic seal towards the outside in order to prevent the elastic seal from migrating into the gap between the seal ring and the shoulder of the seal chamber.
  • this support strip is made of elastic plastic, the hardness of which is higher than the hardness of the elastic seal.
  • this ensures that the support strip itself cannot migrate into the gap between the seal ring and the shoulder of the seal chamber because of an alteration in its shape, and on the other hand, owing to the existing elasticity of the support strip, it can easily be adapted to the shape of the seal chamber, which for example may be round or kidney-shaped.
  • the support strip is made of a teflon material. Teflon has got the property of not being attacked so severely by the abrasive properties of concrete as other rubber or plastic materials, and thus it has got a long service life.
  • the support strip made of plastic and/or teflon contains bronze, whereby its properties improve further, the said bronze portion in particular increasing the crushing strength of the teflon strip, thus preventing the risk of migrating into the gap between the seal ring and the shoulder of the seal chamber.
  • the support strip has a thickness of 1 to 3.5 mm.
  • the support strip is particularly well suited for fulfilling the intended task, if it is approx. 2.5 mm thick. If the support strip is thinner than 1 mm, it itself does not have the necessary stability required to prevent migration of the elastic seal, and the support strip itself might migrate into the gap between the seal chamber and the shoulder of the seal chamber. If the support strip is too thick, it is no more sufficiently elastic to allow for easy insertion into the seal chamber and it would demand unnecesarily much space in the seal chamber.
  • the support strip is preferably cut off from a tape which for example can easily be procured on a roll.
  • the support strip can simply be cut to the length of the circumference of the seal chamber, before the support strip is laid into the seal chamber.
  • the support strip is preferably cut off by an oblique cut to the necessary length and after inserting the support ring, the cut faces should lie as closely as possible next to each other. This ensures that the elastic seal cannot migrate at a circumferential point into a gap of the support strip, thereby restricting its function and/or being exposed to increased wear and tear at the gap.
  • the remaining gap in the support strip after inserting into the seal chamber is smaller than 1 mm.
  • one opening of the passage duct of the pivot body is kidney-shaped, with the elastic seal also being kidney-shaped and being supported by the support strip in the seal chamber.
  • wear plates are arranged at the insides of the housing in the area of the inlet openings and/or outlet openings.
  • These wear plates are preferably made of a metal having a hardness which is higher than the housing itself, so that the insides of the housing are exposed to less wear and tear in the area in which the pivot body is swung to and fro at the housing wall.
  • the wear plates can be exchanged, if required, without necessitating an exchange of the entire housing.
  • FIG. 1 is a schematic representation of a top view on a switchover device of a thick-matter pump
  • FIG. 2 is a side view of the switchover device from FIG. 1 ;
  • FIG. 3 is a schematic view of a section through a seal chamber (Detail A) according to prior art in technology;
  • FIG. 4 is a schematic view of a cut through a seal chamber (Detail A) according to prior art in technology during a pumping procedure;
  • FIG. 5 is a schematic view of an elastic seal with a support strip according to the present invention.
  • FIG. 6 is a support strip according to the present invention in unrolled status
  • FIG. 7 is a perspective view of the cutting edge of a support strip according to the present invention.
  • FIG. 8 is a schematic view of a cut through a seal chamber (Detail A) according to the present invention during a pumping procedure.
  • FIG. 1 illustrates a schematic view from the top onto a switchover device 1 for a thick-matter pump.
  • the switchover device is mainly comprised of an open-top pre-fill vessel 20 with the housing sides 2 a, 2 b, 2 e, 2 f and a bottom 2 c, in which a pivot body 3 is arranged.
  • the pivot body 3 mainly comprises a passage duct 17 with an inlet opening 13 and an outlet opening 14 .
  • the switchover device 1 is suitable, for example, to deliver the concrete conveyed by hydraulically driven delivery cylinders 18 a, 18 b connected to the inlet and outlet openings 19 a, 19 b through the passage duct 17 of the pivot body 3 in the direction of the outlet opening 14 into a concrete delivery tube 17 .
  • FIG. 1 illustrates a schematic view from the top onto a switchover device 1 for a thick-matter pump.
  • the switchover device is mainly comprised of an open-top pre-fill vessel 20 with the housing sides 2 a, 2
  • the delivery cylinder 18 b sucks concrete in a suction stroke from the pre-fill vessel 20 and the delivery cylinder in a simultaneous delivery stroke pushes the concrete through the passage duct 17 of the pivot body 3 into the concrete delivery tube 21 .
  • the pivot body 3 is swiftly switched over by means of a non-illustrated hydraulic unit.
  • the pivot body 3 is pressed by means of the sealing system (Detail A) explained later between the housing walls 2 a and 2 b, but still remains movable for the switchover movement.
  • the sealing system (Detail A) explained later between the housing walls 2 a and 2 b, but still remains movable for the switchover movement.
  • FIG. 2 shows a side view of the switchover device 1 from FIG. 1 , wherein the outlet opening 14 is located on the side facing the viewer and the inlet and outlet openings 13 are located on the side averted from the viewer. From FIG. 2 , it is especially the swinging movement of the pivot body 3 in housing 3 that becomes evident, wherein the pivot body 3 in this drawing is located in position (a), that means upstream to the left-side inlet and outlet opening 19 a.
  • the kidney-shaped outlet opening 14 of the pivot body 3 remains in a position upstream to the outlet opening 15 of housing 2 , but the outlet opening 14 of the pivot body 3 is nevertheless moved to and fro upstream to the outlet opening 15 of the housing side 2 b when swiveled about the swivel axis 11 from position a to position b and vice versa.
  • the change from suction stroke to delivery stroke of the delivery cylinders takes approx. 3 to 15 seconds, depending on the design and size of the thick-matter pump, and since the pivot body 3 stands still during this period of time, the pivot body 3 must be swiveled into the other position within a few tenths of a second during the switchover.
  • a pressure P with up to several hundreds bar prevails in the passage duct 17 both during standstill and during the switchover procedures, and this pressure also takes effect on the sealing unit (Detail A).
  • FIG. 3 shows a schematic detail view of the sealing system (Detail A) from FIG. 1 in accordance with prior art in non-burdened status. It means the pivot body 3 is pressed to have contact with the housing wall 2 b via the elastic seal 16 , seal ring 12 , hard metal coating 4 and the wear plate 5 mounted to the housing wall 2 b, without there being any pressure of concrete in the passage duct 17 .
  • the seal ring 12 in this case is shown as a metal ring with a hard metal coating, but it could also be made of a different solid material that offers high resistivity to the abrasive effect of concrete on pumping.
  • the hard metal coating 4 is not absolutely necessary. In the following, however, a configuration with a metal ring having a hard metal coating is described.
  • the elastic seal 16 which may be comprised of a plastic or rubber material and which may be reinforced in the interior with a metal ring serves the task of pre-tensioning the seal ring 12 against the housing wall 2 and/or wear plate 5 in order to seal the passage duct 17 towards the pre-fill vessel.
  • the elastic seal 16 and the seal ring 12 with the hard metal coating 4 are laid into the seal chamber 8 which is confined towards the outside by the nose-shaped shoulder 10 . In non-installed status, the elastic seal 16 shown here would have a round cross-section.
  • the seal 16 has a slightly oval deformation, whereby the metal ring 12 with the hard metal coating 4 is pressed at pressure p to enter into contact with the wear plate 5 .
  • a gap 9 having the width d is provided for. Since the metal ring 12 is moved also laterally during the switchover cycles, the width of the gap may vary between 0 and approx. 1 mm in operation. It becomes evident that due to this movement, also the elastic seal 16 being subjected to the contact pressure is laterally moved and tumbled.
  • FIG. 4 illustrates the sealing system according to FIG. 3 in operation in conformity with prior art in technology. Because of concrete being conveyed, a very high pressure P now prevails in the passage duct 17 . This pressure P which presses the metal ring 12 via the seal 16 during the pumping procedure additionally to the wear plate 5 , presses the elastic seal 16 in the direction of the nose-shaped shoulder 10 , and moreover, the elastic seal 16 is moved laterally to and fro due to the relative movement of the metal ring 12 towards the seal chamber 8 of the metal ring 12 .
  • the pressure P and the motions of the metal ring 12 involve that the elastic seal 16 is not only pressed into the direction of the nose-shaped shoulder 10 , but also into the gap 9 , whereby on the one hand the metal ring 12 is virtually clamped, but in particular the elastic seal 16 in the area pressed into the gap 9 is subjected to a particular high wear and tear.
  • FIG. 5 illustrates a kidney-shaped elastic seal 16 as utilized in a switchover device 3 of a thick-matter pump in accordance with FIGS. 1 and 2 .
  • a support strip 6 made of teflon material is shown which together with the elastic seal 6 is laid into the seal chamber 8 of the switchover device.
  • the teflon material 6 may advantageously be enriched with bronze in order to increase the hardness of the strip.
  • FIG. 6 shows the support strip 6 in unrolled status.
  • the support strip 6 has the length L which corresponds to the outer circumference of the seal chamber 8 .
  • Clearly visible in FIGS. 5 and 6 are the oblique cutting faces 6 a of the support strip 6 . These oblique cutting faces take the effect that the elastic seal 16 is not point-wise stressed at a circumferential point in case of a slight gap between the ends ( 2 a ) of the inserted support strip 16 , but stressed obliquely over a longer area, thereby distributing the wear due to a gap between the support strip ends ( 2 a ) in the seal chamber 8 at the elastic seal 16 over a broad range.
  • the cutting angle may amount to approx. 30 degrees as illustrated in the drawing, but it should not be too small so that the ends of the strip 16 do not become too thin and might slide into the gap 9 and/or rotate; however, this angle should not be too large either, because otherwise the elastic seal would be stressed too much at one circumferential point.
  • the height H of the support strip 6 amounts to approx. 1 . 5 cm, but it should not exceed the height of the seal chamber 8 in built-in status, because otherwise the support strip 16 is pressed between the metal seal 12 and the upper end of the seal chamber 8 , and the elastic seal 16 would no longer be able to fulfill its function of pressing the metal seal 8 to the wear plate.
  • the height H of the support strip 6 should not be much lower than the height of the seal chamber 8 , because otherwise a gap would occur above or below the laid-in support strip 6 into which the elastic seal 6 might unintentionally penetrate.
  • FIG. 7 shows a view of the oblique cutting face 6 a of the support strip 6 with the thickness D.
  • the thickness D of the support strip here for example amounts to 2.5 mm, but it could also vary between 1 mm and 3 mm.
  • the minimal thickness D should not be less than the maximal width d of gap 9 , because is otherwise there would be a risk in that the support strip 6 migrates into the gap 9 and obstructs the mobility of the metal seal in the seal chamber 8 . Conversely, if the support strip is configured with too much thickness, it does not leave sufficient space for the elastic seal 16 in the seal chamber 8 .
  • FIG. 1 Detail A, in which the support strip 6 is circumferentially laid around the elastic seal 16 in the seal chamber 8 .
  • the elastic seal is deformed only slightly.
  • the metal ring 12 is pushed to and fro during the switchover cycles due to the frictional force F R .
  • support strip 6 shown here may not only be utilized in the kidney-shaped seal chamber 8 of the switchover device illustrated here, but for example also at the round inlet opening 13 on the other side of the pivot body 3 in order to seal the inlet and outlet openings during the pumping cycle.
  • a support strip 16 is not limited to the design version of a switchover device illustrated here, but it could also be utilized for example in S-shaped switchover valves for sealing at inlet and outlet openings.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Details Of Reciprocating Pumps (AREA)
US14/901,296 2013-06-28 2014-06-04 Switchover device for a thick-matter pump Abandoned US20160348655A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102013010768.7 2013-06-28
DE102013010768.7A DE102013010768A1 (de) 2013-06-28 2013-06-28 Umschaltvorrichtung für eine Dickstoffpumpe
PCT/EP2014/061568 WO2014206698A1 (de) 2013-06-28 2014-06-04 Umschaltvorrichtung für eine dickstoffpumpe

Publications (1)

Publication Number Publication Date
US20160348655A1 true US20160348655A1 (en) 2016-12-01

Family

ID=51022294

Family Applications (1)

Application Number Title Priority Date Filing Date
US14/901,296 Abandoned US20160348655A1 (en) 2013-06-28 2014-06-04 Switchover device for a thick-matter pump

Country Status (5)

Country Link
US (1) US20160348655A1 (zh)
EP (1) EP3014121A1 (zh)
CN (1) CN105492765B (zh)
DE (1) DE102013010768A1 (zh)
WO (1) WO2014206698A1 (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10001114B1 (en) * 2017-03-28 2018-06-19 Jessop Initiatives LLC Continuous flow pumping system
US10315850B2 (en) 2017-07-13 2019-06-11 1875452 Alberta Ltd. Proppant conveyor systems and methods of use

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3542374A (en) * 1968-04-24 1970-11-24 Worthington Corp Packing for piston rods in high pressure nonlube reciprocating compressors
US3582094A (en) * 1970-02-16 1971-06-01 Greene Tweed & Co Inc Sealing assembly
US3711104A (en) * 1971-03-16 1973-01-16 Dresser Ind Seal assembly
FR2142224A6 (en) * 1971-06-17 1973-01-26 Plastic Omnium Cie Plastic pressure pipe coupling - incorporating a split skirt seal retained by a captive champhered split ring
US4465441A (en) * 1981-01-31 1984-08-14 Friedrich Wilh. Schwing Gmbh Two-cylinder pump for heavy flowable materials, such as concrete
US4472118A (en) * 1981-04-04 1984-09-18 Friedrich Wilh. Schwing Gmbh Multi-way valves for pumps for conveying heavy flowable materials
US5180294A (en) * 1992-03-04 1993-01-19 Confloat Consulting Ltd. Concrete pump having pressurized seal for swing tube
US20090038856A1 (en) * 2007-07-03 2009-02-12 Particle Drilling Technologies, Inc. Injection System And Method
US20110174713A1 (en) * 2010-01-15 2011-07-21 Hydranautics Brine seal for a filtration device

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4198193A (en) * 1978-05-12 1980-04-15 Walters James F Automatic wear compensation apparatus for concrete pumping hopper apparatus
DE3410211A1 (de) * 1984-03-20 1985-10-03 Gerhard Dr. 7900 Ulm Hudelmaier Vorrichtung zum dichten einer betonpumpe
US5037275A (en) * 1987-06-27 1991-08-06 Karl Schlecht Pipe junction switch for two-cylinder thick-material pump
DE3904862C2 (de) * 1989-02-17 1996-01-18 Schlecht Karl Rohrweiche für Zweizylinder-Dickstoffpumpen
DE19528288C1 (de) * 1995-08-02 1996-02-29 Putzmeister Maschf Zweizylinder-Dickstoffpumpe

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3542374A (en) * 1968-04-24 1970-11-24 Worthington Corp Packing for piston rods in high pressure nonlube reciprocating compressors
US3582094A (en) * 1970-02-16 1971-06-01 Greene Tweed & Co Inc Sealing assembly
US3711104A (en) * 1971-03-16 1973-01-16 Dresser Ind Seal assembly
FR2142224A6 (en) * 1971-06-17 1973-01-26 Plastic Omnium Cie Plastic pressure pipe coupling - incorporating a split skirt seal retained by a captive champhered split ring
US4465441A (en) * 1981-01-31 1984-08-14 Friedrich Wilh. Schwing Gmbh Two-cylinder pump for heavy flowable materials, such as concrete
US4472118A (en) * 1981-04-04 1984-09-18 Friedrich Wilh. Schwing Gmbh Multi-way valves for pumps for conveying heavy flowable materials
US5180294A (en) * 1992-03-04 1993-01-19 Confloat Consulting Ltd. Concrete pump having pressurized seal for swing tube
US20090038856A1 (en) * 2007-07-03 2009-02-12 Particle Drilling Technologies, Inc. Injection System And Method
US20110174713A1 (en) * 2010-01-15 2011-07-21 Hydranautics Brine seal for a filtration device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10001114B1 (en) * 2017-03-28 2018-06-19 Jessop Initiatives LLC Continuous flow pumping system
US10315850B2 (en) 2017-07-13 2019-06-11 1875452 Alberta Ltd. Proppant conveyor systems and methods of use

Also Published As

Publication number Publication date
CN105492765A (zh) 2016-04-13
DE102013010768A1 (de) 2015-01-15
EP3014121A1 (de) 2016-05-04
CN105492765B (zh) 2018-04-24
WO2014206698A1 (de) 2014-12-31

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AS Assignment

Owner name: SCHWING GMBH, GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MERTEN, WOLFGANG;KOCH, THORSTEN;SCHNITTKER, JOSEPH;REEL/FRAME:038272/0880

Effective date: 20160330

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION