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
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/16—Casings; Cylinders; Cylinder liners or heads; Fluid connections
  • F04B53/162—Adaptations of cylinders
  • F04B53/164—Stoffing boxes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B23/00—Adaptations of machines or engines for special use; Combinations of engines with devices driven thereby
  • F01B23/08—Adaptations for driving, or combinations with, pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B31/00—Component parts, details or accessories not provided for in, or of interest apart from, other groups
  • F01B31/12—Arrangements of measuring or indicating devices
• • 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
• • 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
  • F04B9/00—Piston machines or pumps characterised by the driving or driven means to or from their working members
  • F04B9/08—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid
  • F04B9/10—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid
  • F04B9/109—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers
  • F04B9/117—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers the pumping members not being mechanically connected to each other
  • F04B9/1176—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers the pumping members not being mechanically connected to each other the movement of each piston in one direction being obtained by a single-acting piston liquid motor
  • F04B9/1178—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers the pumping members not being mechanically connected to each other the movement of each piston in one direction being obtained by a single-acting piston liquid motor the movement in the other direction being obtained by a hydraulic connection between the liquid motor cylinders

Definitions

• the invention relates to a hydrostatically driven duplex plunger pump for the conveyance of liquids laden with abrasive particles, flowable slurries or emulsions, in which each plunger is provided with
• Type are known as flushing pumps for deep drilling rigs or press water pumps (DE-AS 1 019 563), the pumps which convey the actual flushing medium, however, are designed as double-acting piston pumps which are used to convey abrasive particles
• Liquids and slurries are less suitable than the plunger or plunger pumps provided in the context of the present invention - known per se - in which no piston seals subject to wear are provided. Only the seals which seal the plunger on the outlet side from the plunger cylinder are exposed to the attack of the medium to be conveyed and thus to wear and must therefore be arranged as easily as possible interchangeably and / or be designed in a special manner to protect against wear.
• the invention is based on the object of developing the known hydrostatically driven duplex pumps in such a way that they also deliver at a high delivery rate allow of highly abrasive media, high reliability on the one hand and easy and fast
• this object is achieved according to the invention in that the maximum working stroke of the hydraulic piston-cylinder units is larger than the working stroke of the plunger piston of the respectively coupled feed pump by an amount such that the plunger pistons when the maximum working stroke is fully extended the piston-cylinder units are completely pulled out of the assigned plunger cylinder, however, that the return stroke of the hydraulic piston-cylinder units during normal pump operation, however, is limited by a corresponding control of the hydraulic control elements to a dimension corresponding to the working stroke of the plunger pistons, and that the hydraulic control elements are selectively controllable in such a way that the hydraulic piston-cylinder units perform the maximum working stroke.
• the hydraulic control elements are preferably developed by electrical signals as a function of the stroke position of the plunger in a control unit actuated control valves, the control unit being connected to at least the stroke end positions of the plunger-sensing electrical sensors and having a comparator unit in which the synchronization of the stroke end divisions of the two plunger pistons is compared and, if a plunger remains, a control signal for the associated hydraulic piston-cylinder unit is developed in such a way that the supply of hydraulic medium to the piston-cylinder unit assigned to the leading plunger is reduced or completely blocked until the lagging plunger has reached its attractive position.
• the piston-cylinder units assigned to the plunger can in principle be acted upon separately from a pressure medium source supplying hydraulic medium under pressure.
• a pressure medium source supplying hydraulic medium under pressure.
• Hydraulic medium on the piston ring surfaces of the hydraulic piston-cylinder units designed as differential cylinders A lower hydrostatic driving force is thus generated for the plunger pistons above the action on the full piston surface provided in the second alternative, but a faster piston stroke occurs, since the working spaces of the piston-cylinder units penetrated by the piston rods are smaller by the volume of the piston rod Have swallowing volume and can therefore be filled more quickly.
• the first alternative is therefore expediently used when high delivery rates are aimed at lower pressures, while conversely, in the second case, higher pressures are achieved with lower delivery rates.
• a compensating line is expediently connected, which is controlled by the control unit via a directional valve with the line supplying the hydraulic medium or the line
• Hydraulic medium discharge line connectable or gegms, flow can be closed. Hydraulic medium that is supplied or discharged via the balancing line can therefore compensate for any leakage losses in the hydraulic medium, which would lead to an unsynchronous drive of both plunger pistons.
• the construction of the pump according to the invention can be such that the plunger pumps and the respectively assigned piston-cylinder units are kept flush from one another at a distance corresponding to the maximum possible working stroke of the piston-cylinder units, and the plungers are held by the piston rods bridging this distance Pistons of the respectively assigned hydraulic piston-cylinder unit are connected, in which case the electrical sensors are formed by proximity switches arranged directly next to the piston rods, which are switched by a trigger provided on the respective piston rod.
• the pumps constructed in this way have a relatively large axial extension, especially since the additional stroke of the piston-cylinder units required for the complete removal of the plunger from the plunger cylinder must be taken into account. The axial length of such pumps is reduced if the axial distance between the plunger pumps and the respectively assigned hydraulic piston-cylinder unit results from the use of the component coupling them as a functional part of both
• the electrical sensors for controlling the stroke and the synchronization of the two drives are then proximity switches arranged next to the stroke of the cylinders of the piston-cylinder units, which are switched by a trigger which appears from the outside of the respective cylinder.
• the arrangement of the electrical sensors for controlling the pump is then made possible by the fact that the piston rods of the hydraulic piston-cylinder units are drilled substantially over their entire length and are only closed at the end located in the plunger cylinder, while the hollow bore at the opposite end through the Piston of the piston-cylinder units is passed and in the working space facing away from the plunger cylinder Piston-cylinder unit opens openly that the plunger cylinder-facing working space of the respective hydraulic piston-cylinder unit is penetrated by a non-magnetic material tube, which is held in the end wall which closes this working space on the end facing away from the piston and enters the hollow bore, in which the dead center is the hydraulic piston-cylinder units and, if appropriate, a spacing corresponding to a stroke-center position, magnetic, releasable switches are arranged as electrical sensors, and that a magnet is provided in the hollow bore, which triggers the electrical switches in the respectively assigned stroke position and thus a feedable to the control unit and in develops its processable signal.
• the switches that can be triggered magnetically are expediently arranged in the non-magnetic tube reed contacts, which can be fixed by a cast resin that is poured into the tube after assembly and then cured.
• an embodiment is particularly effective in which the pressure of the sealing liquid is controlled by means of a pressure control device in proportional dependence on the pressure currently prevailing in the medium to be conveyed.
• Figure 1 is a partially sectioned plan view of a first embodiment of a duplex plunger pump according to the invention, in which a circuit diagram of the hydraulic drive of the piston-cylinder units is also shown schematically.
• FIG. 2 shows a longitudinal central section through a single unit of a second embodiment of the plunger pump according to the invention.
• FIG. 3 shows a longitudinal central section through an individual unit of a third exemplary embodiment of a plunger pump according to the invention.
• a duplex plunger or plunger pump according to the invention designated in its entirety by 10, is shown, which is composed of two identical single pump units 10a and 10b arranged in parallel next to each other, which in turn each consist of the actual feed pump 12a or 12b and one each are coupled to the plunger 14 of these feed pumps coupled double-acting hydraulic piston-cylinder unit 16a and 16b.
• the hydraulic piston-cylinder units 16a, 16b can be acted upon by hydraulic pump from a pump 18 in such a way that hydraulic medium can be applied in such a way that their pistons 20 and thus the coupled plunger pistons 14 each perform opposing stroke movements, ie when the feed pumps 12a, b are driven by mechanical rotary drives, for example crank drives, one would speak of a 180 ° phase-shifted stroke movement of the plunger 14.
• the construction of the components of the individual pump units 10a, 10b is largely conventional, so that it suffices to explain the configuration of the feed pumps 12a, b of the piston-cylinder units 16a, b and their coupling only briefly below.
• the feed pumps 12a, b consist of a plunger cylinder 22, from the one end end of which the plunger 14 is sealed by seals 24 against the outlet of the medium to be conveyed and is guided through in a longitudinally displaceable manner.
• the suction line for the medium to be conveyed is connected via a check valve 26, which prevents backflow of the medium sucked in during the suction stroke of the plunger 14 from the plunger cylinder 12 into its interior 28 into the suction line during the subsequent conveying or working stroke.
• the medium to be pumped is displaced into a downstream pressure line 32 via an outlet opening 30 which penetrates the wall of the plunger cylinder 22 in the immediate vicinity of the seals 24, a second check valve 34 arranged downstream of the outlet opening 30 ensuring that the medium conveyed does not return during the subsequent suction stroke is sucked back into the interior 28.
• the check valve 34 can - like the check valve 26 - be designed as a ball check valve.
• one end of a piston rod 38 is fastened, which is guided at its other end, sealed by an end cover 40 of the cylinder 42 of the associated piston-cylinder unit 16a, b End carries the piston 20, which the interior of the
• the plunger cylinders 22 of the feed pumps 12a, b and the cylinders 42 of the piston-cylinder units 16a, b are arranged with aligned longitudinal center lines at a predetermined distance from one another in a supporting structure, which in the case shown has one each, the plunger cylinders 22 and the cylinders 42 Carrier plate 58 or 60 and these plates at the predetermined distance keeping welded longitudinal struts 62 is formed.
• the interconnected ends of the piston rods, 3S and the plunger 14 thus oscillate in the intermediate space formed in the support structure, the connection being made in each case by a separable connecting clamp 64 with a radially circumferential flange 66, which in each case acts as a trigger for electrical elements held by the longitudinal struts 62
• Sensors in the form of non-contact proximity switches 68 is used. These proximity switches 68 are held on the longitudinal beams 62 in such a position that an electrical control signal is generated in them by the radial flange 66 of the respectively assigned connecting clamp 64 when the associated plunger 14 is in one or another dead or dead center position.
• the distance a between the two outermost proximity switches 68 of a single pump unit 10a, b is therefore equal to the working stroke a of the associated plunger 14.
• a further proximity switch 68 can be provided halfway between the proximity switches 68, that is to say with a stroke distance a / 2 his.
• the signals generated in the proximity switches 68 are fed via electrical lines 70 to a control unit 72, from which the application of hydraulic medium to the piston-cylinder units 16a, 16b is controlled.
• the length of the cylinders 42 of the piston-cylinder units 16a, 16b is dimensioned such that the maximum possible working stroke of their pistons 20 is longer than the working stroke a of the plungers 14 by the distance b.
• the additionally possible stroke path b is selected such that the plunger 14 is completely pulled out of the associated plunger cylinder 22 while utilizing the maximum possible working stroke a + b of the piston-cylinder units 16a, b. This may be necessary, for example, if the seals 24 sealing the plungers 14 in the assigned plunger cylinders 22 have to be replaced due to wear. In normal operation, however, due to the arrangement of the proximity switch 68 described, only the normal stroke a is covered in the piston-cylinder units.
• the hydraulic medium required to act on the hydraulic piston-cylinder units 16a, b is supplied by the above-mentioned high-pressure pump 18, which is driven by a motor 78 and which sucks it in from a reservoir 80 and into one electromagnetically feeds switchable directional valve 82 leading line 84, from which on the other hand a line 86 leads back to the reservoir 80.
• the directional control valve 82 in the exemplary embodiment shown is on the other hand via lines 88 and 90 to the work dreams
• valve 82 is switched to unpressurized circulation, i.e. that is pumped by the pump 18
• Hydraulic medium then flows directly back into the reservoir.
• the working spaces 46 of the piston-cylinder units opposite the working spaces 44 are connected directly by the line 56, so that the hydraulic medium which is displaced from the opposite working space 46 when the working space 44 is applied to the one piston-cylinder unit from the piston 20 thereof Flows over the working space 46 of the other piston-cylinder unit, the piston 20 of which shifts, the hydraulic medium coming from the working space 44
• Piston-cylinder sinitude is displaced and returned to the reservoir 80.
• the hydraulic piston-cylinder units 16a, 16b are thus coupled via the line 56 in the sense of a series connection in such a way that their pistons and thus piston rods each perform opposite strokes. It is clear that the switching of the directional valve 82 and thus the control of the stroke movement of the piston-cylinder units from the control unit 72 via a Signal line 92 occurs in each case when the proximity switches 68 signal that the pistons 20 of the piston-cylinder units 16a and 16b have each reached the opposite dead center positions.
• Piston-cylinder unit remains slightly behind during a working or return stroke with respect to the piston 20 of the other piston-cylinder unit, and thus the proximity switch 68 assigned to its owner does not yet provide a signal to the control unit 72 if the proximity switch 68 assigned to the stroke end of the other piston has already signaled the end of the stroke. Because of the absence of the second signal, the control unit therefore does not yet develop a primary switching signal for the directional control valve 82, ie the drive of the plunger pump 10 would come to a standstill. In order to avoid this, a compensating line 94 is connected to the line 56, via which hydraulic medium is fed into the working space 46 of the trailing piston-cylinder unit until the piston 20 of this unit has also reached its end position.
• both proximity switches 68 then supply a signal to the control unit 72, the changeover of the directional control valve 82 is triggered and the piston-cylinder unit is acted upon in the opposite stroke direction with hydraulic medium.
• the electro-hydraulic circuit described inevitably also brings about something like a synchronization of the two piston-cylinder units.
• the control of the replenishment of hydraulic medium via the line 94 is carried out by two hydraulic switching valves 96 and 98, of which the valve 96 is designed as a weighing valve, which is controlled by the pressure in the lines 88 and 90 itself such that it is just below Higher pressure line 88 or 90 connects to the second switching valve 98, which branch can be actuated electromagnetically by the control unit 72 via a signal line 97.
• Such an actuation signal is developed by the control unit 72 when only one of the proximity switches 68 signals the reaching of the dead center position of the piston of its piston-cylinder unit.
• the switching valve 98 is then switched by this signal from the previously closed to an open position, in which, via the switching valve 96, pressurized hydraulic medium is fed until the piston of the second piston-cylinder unit is excited by excitation of it assigned proximity switch 68 reports to the control unit 72.
• FIG. 2 shows a longitudinal section through one of the individual pump units 10a or 10b according to FIG. 1, functionally corresponding single pump unit 110, that is to say by interconnection with a similar pump unit 110 in the manner described above forms a duplex plunger pump according to the invention.
• FIG. 2 shows a longitudinal section through one of the individual pump units 10a or 10b according to FIG. 1, functionally corresponding single pump unit 110, that is to say by interconnection with a similar pump unit 110 in the manner described above forms a duplex plunger pump according to the invention.
• FIG. 2 shows a longitudinal section through one of the individual pump units 10a or 10b according to FIG. 1, functionally corresponding single pump unit 110, that is to say by interconnection with a similar pump unit 110 in the manner described above forms a duplex plunger pump according to the invention.
• FIG. 2 shows a longitudinal section through one of the individual pump units 10a or 10b according to FIG. 1, functionally corresponding single pump unit 110, that is to say by interconnection with a similar pump unit 110 in the
• the fundamental difference between the pump unit 110 and the pump unit 10a is that the piston-cylinder unit 116 is in the opposite position, i.e. is arranged with the piston rod 138 pointing away from the feed pump 112, so that its cylinder 142, which slidably slides into the plunger cylinder 122, simultaneously forms the plunger of the feed pump 112. So that the cylinder 142 can fulfill its function as a plunger, it must be displaceable on the piston 120 and within the interior 128 of the plunger 122, depending on the loading of its working spaces 144 or 146.
• the end of the piston rod 138 remote from the piston must be fixed at a predetermined distance from the plunger cylinder 122, for which purpose a support structure (not shown) corresponding to the support structure 58, 60, 62 described in connection with FIG. 1 can be provided.
• the working spaces 144 and 146 are acted upon via the hollow-bored piston rod 138, an additional tube 147 of smaller diameter being inserted into this hollow bore, which is inserted sealed at the ends in the hollow bore and the hollow bore divided into an intermediate passage channel leading to the working space 146 and an outer passage channel for hydraulic medium which is annular in cross section and leads to the working space 144.
• a radial flange on the cylinder cover 140 closing the cylinder 142 on the piston rod side may serve as the trigger 166 for the proximity switches 168.
• the electrical sensors formed on the preceding exemplary embodiments take place within the pump unit 210, for which the piston rod 238 is provided over substantially its entire length with a hollow bore 239, which is only closed at the end lying on the plunger cylinder 222, while it is at its opposite end is still passed through the piston 220 of the piston-cylinder unit 216.
• the triggering of the reed contacts 268 in the corresponding stroke positions is carried out by a ring magnet 260 arranged in the vicinity of the mouth of the hollow bore 238 in the piston 220, which thus takes over the function of the radial flanges 66 and 166 from the exemplary embodiments described above.
• piston-cylinder units also in the exemplary embodiments according to FIGS. 2 and 3
• the 116 or 216 have a maximum possible work shub that requires the plunger to be pulled out completely, ie the cylinder 142 or the piston rod 238, from the plunger cylinder 122 or 222 for the purpose of simple and quick replacement of the seals 124 or 224.
• the piston stroke during normal operation of the duplex plunger pumps is limited to a working stroke corresponding to the working stroke of the plungers in the plunger cylinder.
• This possibility consists in reducing the pressure difference between the side of the seal directed towards the interior of the plunger cylinder and its opposite side, so that the medium to be conveyed, which is presumably loaded with abrasive particles, tends to occur to a lesser extent between the seal and the plunger.
• This can be done, for example, by applying a pressurized barrier liquid to the back of the seal, it being useful to control the pressure in the barrier liquid as a function of the pressure currently prevailing in the liquid to be conveyed in the interior of the plunger cylinder.
• control of the hydraulic loading of the working spaces of the piston-cylinder units can also be carried out via separate switching valves - possibly even from separate pumps that are separately driven by them Parallel connection. Suitable measures can then only be used to ensure that the opposing piston strokes of the piston-cylinder units are synchronized. This is possible by comparing the electrical signals generated in the electrical sensors as a function of the stroke position on the control unit and corresponding changes in the application of hydraulic medium to the unsynchronized piston-cylinder units. It is also possible to combine two of the described duplex plunger pumps into one pump unit with twice the output, with the corresponding phase-shifted drive of the two pumps being synchronized via the electrical sensors.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Reciprocating Pumps (AREA)

Applications Claiming Priority (2)

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ID=6242265

Family Applications (1)

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• 1984
  • 1984-08-03 DE DE19843428629 patent/DE3428629A1/de active Granted
• 1985
  • 1985-07-30 WO PCT/EP1985/000382 patent/WO1986001260A1/de unknown
  • 1985-07-30 AU AU47206/85A patent/AU4720685A/en not_active Abandoned
  • 1985-07-30 EP EP19850903992 patent/EP0188611A1/de not_active Withdrawn

Non-Patent Citations (1)

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