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
  • 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

• This disclosure relates to a hydraulic pump system for handling a slurry medium at least comprising at least two reciprocating positive displacement pumps, both pumps being arranged for alternating intake of slurry medium via a suction inlet and discharge of slurry medium via a discharge outlet, and piston/cylinder discharge valves for alternating closing and opening each discharge outlet.
• a displacement element such as a piston or plunger
• the reciprocating motion of the displacement element is generated by a mechanism which transfers the rotating motion of the pump drive mechanism into a reciprocating motion of the displacement element.
• this mechanism may include crankshaft, excentric shaft, camshaft or cam disc mechanisms, for example as disclosed in Figure 1 of WO2011/126367.
• Such reciprocating positive displacement pumps are used for pumping slurry media against relatively high pressure, when compared to single stage centrifugal pumps, for example. Further characteristics of such positive displacement pumps include high efficiency and an accurate flow output, but a relatively low flow capacity when compared to centrifugal pumps.
• multiple positive displacement pumps can be arranged in parallel in a manner so that their suction inlets and/or discharge outlets are connected and combined into a single suction and/or discharge line. This means that the sum flow of the individual pumps can meet the total flow requirements of the application.
• the combination of the individual displacement pumps and the interconnecting suction and discharge lines forms a pumping system.
• a phase shift control system for a pump system comprised of multiple reciprocating positive displacement pumps, wherein the speed of the individual pumps is controlled such that a desired phase shift between the pump cycles of the individual pumps is obtained and maintained.
• Each discharge outlet of the individual pumps is provided with a discharge valve, which is to be opened and closed at the right time during the individual pump cycles of the individual pumps.
• the discharge valves also are closed and opened in a controlled manner, preferably such that the pressure across the discharge valve is zero.
• valve rods of the respective discharge valves which are operated independently of each other, create a small change in the flow and therewith a fluctuation in the pressure in the outlet.
• a hydraulic pump system for handling a slurry medium comprising at least two reciprocating positive displacement pumps, both pumps being arranged for alternating intake of slurry medium via a suction inlet and discharge of slurry medium via a discharge outlet, and piston/cylinder discharge valves for alternating closing and opening each discharge outlet, as well as control means for controlling the alternate closing and opening of both piston/cylinder discharge valves, such that during operation no volume difference occurs in the discharge of slurry medium.
• control means comprise a lever assembly interconnecting the pistons of both piston/cylinder driven valves.
• said lever assembly comprises a lever having two ends, each end being hingely connected with the piston of one of said piston/cylinder driven valves.
• piston/cylinder discharge valves are hydraulic piston/cylinder driven discharge valves and wherein said control means comprise a hydraulic line interconnecting both cylinders of said hydraulic piston/cylinder driven discharge valves.
• the hydraulic line can interconnect both cylinders at the piston side thereof, whereas in another embodiment said hydraulic line interconnects both cylinders at the cylinder side thereof.
• each hydraulic piston/cylinder driven discharge valve can comprise a first sensor for sensing the position of the piston in the closed position of the discharge valve as well as a second sensor for sensing the position of the piston in the open position of the discharge valve.
• the system may further comprise an hydraulic refill means for adding hydraulic medium to a hydraulic piston/cylinder driven discharge valve based on signals generated by the first sensor of a discharge valve and the second sensor of the other discharge valve such that the combined hydraulic volume of both pistons chambers and the interconnecting hydraulic line is always so that the pistons will reach their extreme position during operation of the pump system.
• an hydraulic refill means for adding hydraulic medium to a hydraulic piston/cylinder driven discharge valve based on signals generated by the first sensor of a discharge valve and the second sensor of the other discharge valve such that the combined hydraulic volume of both pistons chambers and the interconnecting hydraulic line is always so that the pistons will reach their extreme position during operation of the pump system.
• the pump system can further comprise one or more hydraulic piston/cylinder driven suction valves for alternating closing and opening each suction inlet.
• the pump system can further comprise a pump housing having a central inlet interconnecting both suction inlets as well as a central outlet interconnecting both discharge outlets.
• said pump housing can comprise two pump chambers, each pump chamber being interconnected with one of said reciprocating positive displacement pumps, and each pump chamber being provided with a suction inlet and a discharge outlet.
• Figure 1 is a first partial view of an embodiment of a pump system in accordance with the present disclosure
• Figure 2a a second partial view of an embodiment of a pump system in accordance with the present disclosure
• Figure 2b a partial view of another embodiment of a pump system in accordance with the present disclosure
• Figure 2c a partial view of yet another embodiment of a pump system in accordance with the present disclosure
• FIG. 3 a pump characteristic of an embodiment of a pump system in accordance with the present disclosure.
• FIG. 1 and Figure 2a combined disclose a non-limitative embodiment of an hydraulic pump system.
• the hydraulic pump system is denoted with reference numeral 10 and consists of at least two reciprocating positive displacement pumps 100 and 200 which are connected to a pump housing 11.
• Each of the reciprocating positive displacement pumps 100 and 200 consist of a pump structure in which a displacement element 101 (201), shaped as a piston, is movable accommodated in a cylinder housing 104 (204).
• the displacement element 101 (201) is connected via a piston rod 102 (202), which is displaced in a reciprocating manner using a pump drive mechanism 103 (203), not shown.
• Such a reciprocating positive displacement pump is capable of pumping or handling a slurry medium against relatively high pressure when compared to other types of pumps, such as centrifugal pumps.
• a positive displacement pump (as denoted with reference numeral 100 in Figure 1) can operate at a high pressure level and generate an accurate flow output of the slurry medium to be displaced, albeit with a relatively low flow capacity.
• multiple reciprocating positive displacement pumps (in Figure 1 two of such pumps 100, 200 are shown) are used in a parallel manner as depicted in Figure 1 and their combined pump characteristic is used for obtaining the required and necessary increased discharge flow of the slurry medium.
• the pump drive mechanism 103 (203) are driven in such a manner that the displacement elements 101 (201) are moving in a reciprocating manner, but also in an Out-of-phase' manner. This means that one positive displacement pump performs its discharge stroke, whereas the other positive displacement pump performs its suction stroke.
• the alternating suction and discharge strokes of the two positive displacement pumps results in a combined discharge flow of the individual pumps, the sum of which can meet the total flow requirements of the industrial application in which the hydraulic pump system is to be implemented.
• FIG 2a discloses in more detail another part of the pump system 10 in particular the pump housing 1 1 to which both reciprocating positive displacement pumps 100 and 200 are connected.
• the pump housing 1 1 is provided with a central suction inlet 12 and a central discharge outlet 18 for the intake and discharge of slurry medium to be pumped by the pump system 10.
• the central suction inlet 12 is in fluid communication with suction inlet chambers 14a (14b) via suction inlets 13a (13b).
• Each individual suction inlet 13a (13b) can be opened and closed by so-called hydraulic piston/cylinder driven suction valves 30a (30b).
• Each suction valve 30a (30b) comprises a valve body 31a (31 b) which cooperates with the seat of the individual suction inlet 13a (13b) when said suction valve 30a (30b) is in his closed position.
• Each valve body 31 a (31 b) is mounted to a piston rod 32a' (32b'), which rod 32a' (32b') is provided with a piston element 32a (32b) which is movable accommodated in in a valve housing 30a' (30b').
• the piston element 32a (32b) and the valve housing 30a' (30b') define a cylinder chamber 33a (33b) which is filled with a hydraulic medium.
• the hydraulic medium can be introduced in an alternating manner on either side of the piston element 32a (32b) via hydraulic lines 34a -35a (34b-35b) and by means of a manifold valve 36a (36b) which connects to supply lines P2 and T2.
• Supply line P2 contains a reservoir 40 for hydraulic medium.
• Supply of hydraulic medium to either side of the piston element 32a (32b) causes the hydraulic valve 30a (30b) to open or close the respective suction inlet 13a (13b) by means of the valve body 31 a (31 b).
• Each suction chamber 14a (14b) is in fluid communication with the cylinder chamber 104 (204) in which the displacement element 101 (201) is displaced in a reciprocating manner during operation.
• Each individual suction chamber 14a (14b) is furthermore provided with a discharge outlet 15a (15b). Both discharge outlets 15a (15b) communicates in a combined discharge chamber 16 and further with the central discharge outlet 18.
• Both individual discharge outlets 15a (15b) are arranged to be opened and closed by discharge valves 20a (20b).
• Each discharge valve 20a (20b) comprises a valve body 21a (21 b) which cooperates with the seat of the individual discharge outlet 15a (15b) when said discharge valve 20a (20b) is in his closed position.
• the discharge valve 20b is depicted in its closed position where valve body 21 b fits in the seat of the discharge outlet 15b thereby closing the suction chamber 14b from the combined discharge chamber 16.
• the discharge valve 20a is in its open position allowing fluid communication between the suction chamber 14a and the central discharge chamber 16 (and hence the central discharge outlet 18).
• suction valve 30a is in its closed position having a valve body 31a which closes the seat of the suction inlet 13a.
• the other suction valve 30b is in its open condition allowing the suction inlet 13b to be in fluid communication with the central inlet 12 and the suction chamber 14b.
• the positive displacement pump 100 performs its discharge stroke wherein the discharge element 101 is displaced in the cylinder 104 discharging any slurry medium contained in the suction chamber 14 via the discharge outlet 15a, the central discharge chamber 16 towards the central discharge outlet 18, and hence out of the pump system.
• the positive displacement pump 200 performs its suction stroke wherein the displacement element 201 performs a movement which is contrary to the movement of the displacement element 101 of the positive displacement pump 100 during the discharge stroke.
• slurry medium is taken from the central suction inlet 12 through the suction inlet 13b into the suction chamber 14b.
• the intake amount of slurry via the suction inlet is defined by the amount of slurry medium being displaced by the previous discharge stroke of said positive displacement pump.
• the suction valve 30b is closed under simultaneous opening of the suction valve 30a.
• the discharge valve 20a is closed whereas the discharge valve 20b is opened.
• the subsequent suction stroke of the positive displacement pump 100 causes slurry medium to be taken in the now discharged pump chamber 14a via the suction inlet 13a and the slurry medium contained in the other suction chamber 14b is now being discharged by the positive displacement pump 200 during its discharge stroke. Said discharged slurry medium is forced through the now open discharge outlet 15b into the combined discharge chamber 16 and towards the central discharge outlet 18.
• the discharge valves are operated independently.
• the valve body 21 b together with the part of the piston rod 22b extending in the discharge chamber 16 represents a certain volume, which is not occupied by slurry medium present in the discharge chamber 16.
• this volume previously occupied by the extended piston rod and valve body becomes available to the overall slurry medium volume in the discharge chamber 16. This extra volume becoming available causes a volume drop and hence a temporary pressure drop occurs.
• each positive displacement pump performs a pre-compression stroke on the slurry medium to be discharged in their respective pumping chamber 14a (or 14b) prior to the opening of the respective valve body 21a (or 21 b) of the discharge valves 20a (or 20b).
• Such pre-compression stroke is depicted in Figure 3, which discloses to the pump characteristic and sequence control of one displacement element 101 (201) of each positive displacement pump.
• Each pump performs three stages in a sequential manner:
• the pump switches to the suction stroke.
• the actual required velocity V2 of the suction stroke is determined by controlling the time on which the discharge valve of the pre-compressed pump is opened.
• the pump system 10 as disclosed in Figure 1 and 2a is capable of generating a discharge flow of the displaced slurry medium through the central discharge outlet 18 with no pressure fluctuations resulting in a constant consistency of the biomass slurry medium. This leads to an improved and constant product quality of the biomass slurry medium for further processing in a biomass installation.
• control means which control the alternate closing and opening of both piston/cylinder discharge valves 20a-20b, such that during operation no volume difference occurs in the discharge 18 of slurry medium.
• said control means comprise a hydraulic line 24 which interconnects both cylinder chambers 23a and 23b of the discharge valves 20a and 20b.
• each discharge valve 20a comprises a valve body 21a (21 b) which fits in the seat of the discharge outlet 15a (15b).
• the valve body is mounted on a piston rod 22a' (22b') which ends with a piston element 22a (22b), which is movable accommodated in a valve housing 20a' (20b').
• the piston element 22a (22b) and the valve housing 20a' (20b') define a cylinder chamber 23a (23b) which is filled with a hydraulic medium. Due to the hydraulic interconnection between both cylinder chambers 23a and 23b via the interconnecting hydraulic line 24, no volume difference between both discharge valves will occur during the simultaneous switching of both discharge valves 20a and 20b from their open and closed position.
• reference numeral 24' depicts a hydraulic line, similar to the hydraulic line 24 of Figure 2a, which interconnects both valve housings 20a' and 20b' of the discharge valves 20a and 20b on the cylinder side thereof at the side of the piston rods 22a'-22b' opposite to the side of the piston elements 22a (22b).
• valve housings 20a' and 20b' By interconnecting both valve housings 20a' and 20b' via the interconnecting hydraulic line 24-24', these small volume and pressure pulsations are no longer present as the displaced volume of one discharge valve is compensated by the same volume change created by the other discharge valve.
• each discharge valve 20a (20b) is provided with sensors 25a-26a (25b-26b) which detect the extreme positions of the piston elements 22a (22b) within the cylinder chamber 23a (23b) when in fully closed or fully open position.
• the sensor 25a (25b) will generate a signal when the valve body 21 a (21 b) is completely closing their respective discharge outlet 15a (15b) as the sensor 25a (25b) will properly detect the position of the piston element 22a (22b) in that extreme closing position.
• sensor 26a (26b) will detect the piston element 22a (22b) in its other extreme position, meaning that the discharge valve 20a (20b) is fully open.
• the control mechanisms of both of the discharge valves 20a-20b are interconnected.
• Sensor 25a (which detects the fully closed position of the discharge valve 20a) is interconnected with the sensor 26b (which detects the fully open position of the discharge valve 20b) and likewise sensor 25b (which detects the fully closed position of the discharge valve 20b) is interconnected with the sensor 26a (which detects the fully open position of the discharge valve 20a).
• the opening of say the hydraulic valve 20b (starting from the situation in Figure 2) will be detected by the sensor 25b and will simultaneously also be detected by sensor 26a as the discharge valve 20a is being moved towards its closed position.
• the simultaneous actuation of the sensor 26b and 25a will trigger the fully open position of the discharge valve 20b and the fully closed position of the discharge valve 20a. Any deviation of the simultaneous actuation of both sensor pairs 25a-26b and 25b-26a will be a signal that a change in the volume occupied by the hydraulic medium in the cylinder chambers 23a and 23b and the hydraulic line 24-24' has occurred.
• valve 29 Any shortage of hydraulic medium can be supplied via the valve 29 and interconnecting line 24 (24'). Likewise any surplus of hydraulic medium can be removed interconnecting line 24 (24') and valve 29.
• lever assembly 240 comprises a lever 240 having two ends, each end being hingely connected with either piston element 22a (22b) of one of said piston/cylinder driven valves 20a-20b.
• lever assembly 240 comprises two sub-lever elements 230a-230b, each connected to their respective piston element 22a-22b as well as with either end of the lever 240.
• each connection is a hinge connection.
• the lever 240 is hingely connected at its mid point 241a with the solid world.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Details Of Reciprocating Pumps (AREA)
• Reciprocating Pumps (AREA)
• Control Of Positive-Displacement Pumps (AREA)

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Citations (5)

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• 2016
  • 2016-03-03 JP JP2017543947A patent/JP6701216B2/ja active Active
  • 2016-03-03 CN CN201680014425.5A patent/CN107407266B/zh active Active
  • 2016-03-03 EP EP16718503.2A patent/EP3268607B1/en active Active
  • 2016-03-03 AU AU2016229643A patent/AU2016229643B2/en active Active
  • 2016-03-03 BR BR112017019112-1A patent/BR112017019112B1/pt active IP Right Grant
  • 2016-03-03 CA CA2977442A patent/CA2977442C/en active Active
  • 2016-03-03 WO PCT/NL2016/050147 patent/WO2016144161A1/en active Application Filing
• 2017
  • 2017-08-24 ZA ZA201705784A patent/ZA201705784B/en unknown
• 2020
  • 2020-12-23 AU AU2020294221A patent/AU2020294221A1/en not_active Abandoned

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