High-density solids pump and method for operating a high-density solids pump

Abstract

The invention relates to a high-density solids pump (10) with two conveying cylinders (16, 18), the conveying pistons (34, 36) of which are each rigidly connected to a drive piston (38, 40) of an associated drive cylinder (26, 28) via a common piston rod (30, 32), wherein a conveying operating mode is provided in which the conveying cylinders (16, 18) are driven in push-pull operation, in order to convey high-density solids (58) via a diverter valve (24) alternately connected to the conveying cylinders (16, 18) from a hopper (14) into a conveying pipe (56) (50), and a cleaning operating mode is provided in which the conveying cylinders (16, 18) jointly adopt an end position on the hopper side and the diverter valve (24) is alternately switched between the two conveying cylinders (16, 18).

Description

12.04.2024 / HE Thick matter pump and method for operating a thick matter pump Technical field

[0001] The present invention relates to a slurry pump and a method for operating a slurry pump. Description of the Prior Art

[0002] A mobile slurry pump, particularly a concrete pump, typically has a pre-assembled mounting frame that is mounted on and connected to the chassis of a truck. The mounting frame is designed, among other things, to accommodate a core pump with a material feed container or hopper and a drive assembly for controlling the functional units. A two-cylinder piston pump is typically used as a core pump. This pump has two hydraulic drive cylinders and delivery cylinders connected in pairs. The pistons are connected in pairs via a common piston rod that extends through a water tank and can be driven in push-pull via a hydraulic control system. For this purpose, the drive cylinders are alternately pressurized with oil at one end and are hydraulically coupled to one another at the other end via a connecting line using so-called rocking oil.The concrete is fed through the hopper, which contains a pipe switch. The piston rods are alternately pivoted on the inlet side in front of the front openings of the two delivery cylinders and, on the outlet side, flow into a delivery line that is guided over a distribution boom. Accordingly, the common piston rods with the drive piston and delivery piston are displaced back and forth in opposite directions in the longitudinal direction of the chassis during operation. Such an arrangement is described, for example, in DE 3834 678 A1 and EP 2867 531 B1. Summary of the invention

[0003] Based on this, the invention proposes a slurry pump with the features of claim 1 and a method for operating a slurry pump with the features of claim 6. Furthermore, the invention proposes a computer program with the features of claim 11 and a control device for a slurry pump with the features of claim 13.

[0004] The invention is based on the discovery of providing a cleaning operating mode for a slurry pump of the type described above, in which the delivery cylinders jointly assume a hopper-side end position and the pipe switch alternates between the two delivery cylinders. The invention includes a reverse pumping process for emptying the delivery cylinders and the delivery line. By removing (with bottom-side drive of the drive cylinders) or adding (with rod-side drive of the drive cylinders) rocking oil, the stroke of the delivery cylinders is shortened so that they can jointly assume the hopper-side end position.

[0005] Further advantages and embodiments of the invention emerge from the subclaims, the description and the accompanying drawings.

[0006] The invention also relates to a computer program with program code means suitable for executing a method according to the invention when the computer program is executed on a computer. Both the computer program itself and the program stored on a computer-readable medium are claimed.

[0007] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0008] The invention is illustrated schematically in the drawing using an exemplary embodiment and is described in detail below with reference to the drawing. Brief description of the drawing

[0009] Figure 1 shows a schematic, partially sectioned, perspective view of a thick matter pump according to the invention with core pump and material feed container.

[0010] Figure 2 shows a schematic representation of the thick matter pump of Figure 1 in a partially transparent top view with bottom-side drive.

[0011] Figure 3 shows the top view of Figure 2 in a more schematic form.

[0012] Figures 4 to 6 illustrate the sequence of a cleaning operating mode according to the invention in a representation comparable to Figure 3.

[0013] Figure 7 shows a variant of the illustration in Figure 3 with a rod-side drive.

[0014] Figures 8 to 10 illustrate the sequence of a cleaning operating mode according to the invention in the embodiment of Figure 7. Detailed description

[0015] Identical and similar features shown in the individual figures are designated by the same reference numerals.

[0016] Figures 1 and 2 show a slurry pump 10 according to the invention, which comprises a core pump 12 and a material feed container or hopper 14. The core pump 12 has a first feed cylinder 16 and a second feed cylinder 18, whose end openings 20, 22 open into the hopper 14 and are alternately connectable to a feed line 22 via a pipe switch 24 during the pressure stroke and are open towards the hopper 14 during the suction stroke, sucking in the material 24.

[0017] The feed cylinders 16, 18 are driven in push-pull via respective first and second hydraulic drive cylinders 26, 28. For this purpose, Delivery pistons 34, 36 of the delivery cylinders 16, 18 are connected to pistons 38, 40 of the drive cylinders 26, 28 via a common piston rod 30, 32. In the area between the delivery cylinders 16, 18 and the drive cylinders 26, 28 there is a water tank 42 through which the piston rods 30, 32 extend.

[0018] In the illustrated embodiment, the drive cylinders 26, 28 are alternately pressurized with pressurized oil on the base side via pressure lines 44, 46 with the aid of a hydraulic pump. At their rod-side ends, the drive cylinders 38, 40 are hydraulically coupled to one another by a connecting line 48. The so-called rocking oil is pumped back and forth between the drive cylinders 26, 28 via this connecting line 48 during the alternating pressure and suction stroke movements of the pistons 38 and 40.

[0019] A 3 / 3-way valve 50 is connected to the connecting line 48, which enables the controlled supply and discharge of rocking oil in the manner described below. The inlet and outlet connections 52, 54 of the directional valve 50 can be pressurized with high pressure via a pump P or connected to a tank T at low pressure level.

[0020] If, in the case of a delivery operating mode shown in Figures 2 and 3, pressure oil is supplied to the first drive cylinder 26 via line 44 on the bottom side (bottom-side drive) and the returning oil from the second drive cylinder 28 is returned to the low-pressure level or tank level via line 46, the first piston arrangement 34, 38 moves in the direction of the arrow P1 and the piston arrangement 32, 40 in the direction of the opposite arrow P2. At the same time, thick material, in particular concrete, located in the first conveyor cylinder 16 is conveyed in the direction of the arrows P3 via the pipe switch 24 under corresponding pressure into a conveyor line 56, while material 58 is sucked from the hopper 14 into the second conveyor cylinder 18 via the second conveyor piston 36 in the direction of the arrow P4.

[0021] After the described pressure and suction stroke movement has been carried out, the pressure on the pressure lines 44, 46 is reversed and the pipe switch 24 is switched over to the front opening 22 of the second conveyor cylinder 18, so that the previously sucked thick material from the second conveyor cylinder 18 can be conveyed via the second conveyor piston 36 via the pipe switch 24 under appropriate pressure into the conveyor line 56 and material 58 can be sucked from the hopper 14 into the first conveyor cylinder 16 by the first conveyor piston 34.

[0022] After the pumping process has ended, not only the hopper 24 but also the delivery cylinders 16, 18, as well as their front openings 20, 22 and delivery pistons 34, 36, must be cleaned to prevent hardening of the remaining thick material. For this purpose, the operator can initiate a cleaning mode according to the invention, for example, by pressing a button provided on a control device of the thick material pump. The sequence of the cleaning mode according to the invention is illustrated using an exemplary embodiment in Figures 4 to 6.

[0023] In a first step, reverse pumping of the core pump is initiated. the pipe switch 24 to the delivery cylinders 16, 18 is operated asynchronously, ie the pipe switch 24 is assigned to or switched on with the delivery cylinder that will next perform a suction stroke (instead of the delivery cylinder, which will next perform a pressure stroke, as in regular pumping operation). This situation is illustrated in Figure 4. Reverse pumping enables the delivery cylinder (the second delivery cylinder 18 in the figure), which is still filled with thick material 58 (from the last pumping process), to be emptied into the hopper 14, and also allows any thick material remaining in the pipe switch 24 or the delivery lines 56 to be sucked out by the other delivery cylinder (the first delivery cylinder 16 in the figure).

[0024] Simultaneously with the reverse pumping, rocking oil 60 is fed into the tank T via the connecting line 48, for example via the directional control valve 50 described in connection with Figure 2 (which is not shown in the illustration of Figures 3 to 6 for the sake of clarity).

[0025] The reverse pumping according to the invention is carried out over several alternating piston strokes until a short stroke, i.e., a shortening of the possible stroke of the drive cylinders 38, 40, is established by reducing the amount of rocking oil 60 in the cylinders 26, 28, as illustrated in Figure 5. At this moment, the pump is switched off. The size of the short stroke, at which the reverse pumping movement of the delivery pistons 16, 18 is set (i.e., stopped), can, for example, be parameterized, i.e., adjustable or preset. In this situation- ation, the difference or offset between the two cylinder positions is significantly smaller and the amount of rocking is already significantly reduced.

[0026] In a next step, rocking oil 60 is further fed into the tank T until both delivery pistons 34, 36 come to lie in a funnel-side end position, ie close to their front openings 20, 22, as is illustrated in the illustration in Figure 6.

[0027] After the delivery pistons 34, 36 have reached the described end position on the funnel side, the pipe switch 24 is reactivated, so that it switches back and forth between the two front openings 20, 22. This is illustrated in Figure 6 by the two pipe switch positions superimposed by dashed lines. According to the invention, the activation of the pipe switch 24 can be time-controlled, whereby the duration of the switching intervals can be parameterized, i.e., adjustable or predefined.

[0028] During this time, the operator can clean the delivery cylinders, for example, by spraying the front openings and the cylinder interior between the front openings and the delivery pistons with water under sufficient pressure. These are alternately released by the pipe switch in a time-controlled manner. Due to the end position of the delivery pistons, only a very small space behind the front openings needs to be cleaned, saving time and water and ensuring optimized cleaning of the delivery piston fronts.

[0029] After cleaning is complete, the operator can stop the cleaning mode by pressing a corresponding button or by pressing the button already pressed to initiate the cleaning mode again, whereupon rocking oil 60 is fed in again via the inlet connection 52 until the regular counter-rotating piston positions are reached again.

[0030] Figures 7 to 10 illustrate an embodiment of the invention with a rod-side drive.

[0031] According to the embodiment shown in Figure 7, the drive cylinders 26, 28 are alternately pressurized with pressurized oil via rod-side pressure lines 44, 46 with the aid of a hydraulic pump. At their bottom ends, the drive cylinders 38, 40 are hydraulically coupled to one another by a connecting line 48. The rocking oil is pumped back and forth between the drive cylinders 26, 28 via this connecting line 48 during the alternating pressure and suction stroke movements of the pistons 38 and 40.

[0032] A directional control valve (not shown) is connected to the connecting line 48, which enables the controlled supply and discharge of rocking oil in the manner described below. The inlet and outlet connections of the directional control valve can be supplied with pressure, for example, via a pump, or connected to a tank or to the rod-side pressure lines 44, 46.

[0033] Figure 7 shows the slurry pump 10 in the conveying mode with the first conveying cylinder 16 in a funnel-side end position, after it has previously conveyed thick material located therein via the pipe switch 24 under appropriate pressure into a conveyor line 56, while the conveyor piston 36 of the second conveyor cylinder 18 has sucked material 58 from the funnel 14. Next, in this position, the pipe switch 24 (assigned to the first conveyor cylinder 16) is switched from the position shown in Figure 7 to the position shown in Figure 8, in which the pipe switch 24 is assigned to the second conveyor cylinder 18 filled with material 58.

[0034] Subsequently, in the conveying mode, pressure oil is supplied to the rod side of the first drive cylinder 26 via line 44 (rod-side drive), and the returning oil from the second drive cylinder 28 is returned to the low-pressure level or tank level via line 46, and the first piston arrangement 34, 38 moves in the direction of arrow P5 and the second piston arrangement 32, 40 moves in the opposite direction of arrow P6. At the same time, material 58 is sucked from the hopper 14 into the first conveying cylinder 16 via the first conveying piston 34, while thick material located in the second conveying cylinder 18 is conveyed via the pipe switch 24 under appropriate pressure into a conveying line 56 (see end position in Figure 8).

[0035] As already described above, after completion of the described pumping process, not only the hopper 24, but also the feed cylinders 16, 18, as well as their front openings 20, 22 and feed pistons 34, 36, must be cleaned to prevent hardening of the residues of thick material. For this purpose, the operator initiates a cleaning mode according to the invention. e.g. by pressing a button on a control device of the slurry pump.

[0036] The sequence of the cleaning operating mode according to the invention with rod-side drive is illustrated in the representation of Figures 8 to 10.

[0037] In a first step, reverse pumping of the core pump is initiated. The connection of the pipe switch 24 to the delivery cylinders 16, 18 is operated asynchronously, i.e., the pipe switch 24 is assigned or connected to the delivery cylinder that will next perform a suction stroke (instead of the delivery cylinder, as in regular pumping operation, which will next perform a pressure stroke), thus, in the situation shown in Figure 8, to the second delivery cylinder 18.

[0038] The reverse pumping enables the emptying of the conveyor cylinder (still filled with thick material 58 from the last pumping process) (i.e. in the illustration of Figure 8 the first conveyor cylinder 16) into the hopper 14 and the emptying of thick material remaining in the pipe switch 24 or the conveyor lines 56 by the corresponding other conveyor cylinder (in the illustration of Figure 8 the second conveyor cylinder 18).

[0039] Simultaneously with the reverse pumping, rocking oil 60 is supplied via the connecting line 48, for example via a directional control valve 50 (not shown). For this purpose, the directional control valve can be connected to a tank with a rocking oil reservoir, or the supply can be effected by connecting the connecting line 48 to the pressure lines 44, 46 (as is generally known to the person skilled in the art and is described, for example, in EP 2867 531 B1).

[0040] The reverse pumping according to the invention is carried out over several alternating piston strokes until a short stroke, i.e. a shortening of the possible stroke of the drive cylinders 38, 40, is established by increasing the quantity of rocking oil 60 in the cylinders 26, 28, as illustrated in Figure 9. At this moment, the pump is switched off. The size of the short stroke, at which the reverse pumping movement of the delivery pistons 16, 18 is set (i.e., stopped), can, for example, be parameterized, i.e., adjustable or preset. In this situation, the difference or offset between the two cylinder positions is significantly smaller, and the rocking amount is already significantly reduced.

[0041] In a next step, rocking oil 60 is further fed into the drive cylinders 26, 28 until both feed pistons 34, 36 come to lie in a funnel-side end position, ie close to their front openings 20, 22, as is illustrated in the illustration in Figure 10.

[0042] After the delivery pistons 34, 36 have reached the described end position on the funnel side, the pipe switch 24 is reactivated, so that it switches back and forth between the two front openings 20, 22. This is illustrated in Figure 10 by the two pipe switch positions superimposed by dashed lines. According to the invention, the activation of the pipe switch 24 can be time-controlled, whereby the duration of the switching intervals can be parameterized, i.e., adjustable or predefined.

[0043] During this time, the operator can clean the conveyor cylinders as described above in connection with Figure 6.

[0044] After cleaning is complete, the operator can stop the cleaning mode - also as described above - by pressing a corresponding button or by pressing the button already pressed to initiate the cleaning mode again, whereupon rocking oil 60 is fed out again via the inlet connection until the regular opposing piston positions are reached again. List of reference symbols 10 Thick matter pump 12 Core pump 14 Material feed container or hopper 16 First delivery cylinder 18 Second delivery cylinder 20 First front opening 22 Second front opening 24 Pipe switch 26 First hydraulic drive cylinder 28 Second hydraulic drive cylinder 30 Common piston rod 32 Common piston rod 34 First delivery piston 36 Second delivery piston 38 Piston of the first drive cylinder, drive piston 40 Piston of the second drive cylinder, drive piston 42 Water tank 44 Pressure line 46 Pressure line 48 Connecting line, rocking oil line 50 3 / 3-way valve 52 Inlet connection 54 Outlet connection 56 Delivery line 58 Material, thick matter 60 Rocking oil P Pump P1 Arrow P2 Arrow P3 Arrows P4 Arrow P5 Arrow P6 Arrow T Tank

Claims

Patent claims 1. Thick matter pump (10) with two delivery cylinders (16, 18), the delivery pistons (34, 36) of which are each rigidly connected to a drive piston (38, 40) of an associated drive cylinder (26, 28) via a common piston rod (30, 32), wherein a delivery operating mode is provided in which the delivery cylinders (16, 18) are driven in push-pull in order to convey thick matter (58) from a hopper (14) via a pipe switch (24) alternately connected to the delivery cylinders (16, 18) into a delivery line (56) (50), and a cleaning operating mode is provided in which the delivery cylinders (16, 18) jointly assume a funnel-side end position and the pipe switch (24) is alternately switched between the two delivery cylinders (16, 18). 2.Thick matter pump (10) according to claim 1, in which, to initiate the cleaning operating mode, reverse pumping takes place with an asynchronous, alternating assignment of the pipe switch (24) to the delivery cylinders (16, 18) compared to the delivery operating mode.

3. Thick matter pump (10) according to claim 2, in which, parallel to the reverse pumping process, a shortening of the strokes of the delivery cylinders (16, 18) takes place until the delivery pistons (34, 36) are in a funnel-side end position.

4. Thick matter pump (10) according to claim 3, in which the drive cylinders (26, 28) are in communication with one another via a rocking oil line (48) arranged on the rod side, exchanging rocking oil (60), and the shortening. The strokes of the delivery cylinders (16, 18) are effected by supplying rocking oil (60).

5. A slurry pump (10) according to claim 3, wherein the drive cylinders (26, 28) communicate with each other via a rocking oil line (48) arranged on the bottom side, exchanging rocking oil (60), and the shortening of the strokes of the delivery cylinders (16, 18) is effected by supplying rocking oil (60).Method for operating a thick matter pump (10) with two feed cylinders (16, 18) (70, 80), the feed pistons (34, 36) of which are each rigidly connected to a drive piston (38, 40) of an associated drive cylinder (26, 28) via a common piston rod (30, 32), wherein in a feed operating mode the feed cylinders (16, 18) are driven in push-pull in order to feed thick matter (58) from a hopper (14) into a feed line (56) via a pipe switch (24) alternately connected to the feed cylinders (16, 18), and in a cleaning operating mode the feed cylinders (16, 18) are jointly brought into a hopper-side end position and the pipe switch (24) alternately releases the feed cylinders (16, 18).

7. Method according to claim 6, wherein, to initiate the cleaning operating mode, reverse pumping is carried out with an asynchronous alternating assignment of the pipe switch (24) to the conveying cylinders (16, 18) compared to the conveying operating mode.

8. The method according to claim 7, wherein, parallel to the reverse pumping, the strokes of the delivery cylinders (16, 18) are shortened until the delivery pistons (34, 36) are in a funnel-side end position.

9. The method according to claim 8, wherein, to shorten the strokes of the delivery cylinders (16, 18), rocking oil (60) is drained when the drive cylinders (26, 28) are in communication with one another via a rocking oil line (48) arranged on the rod side, exchanging rocking oil (60).

10. The method according to claim 8, wherein, to shorten the strokes of the delivery cylinders (16, 18), rocking oil (60) is supplied when the drive cylinders (26, 28) are in communication with one another via a rocking oil line (48) arranged on the bottom side, exchanging rocking oil (60). 11.Computer program with program code means for carrying out all steps of a method according to one of claims 6 to 10, when the computer program is executed on a computer or a corresponding computing unit, in particular a control device of a slurry pump (10).

12. Control device for a slurry pump (10), in particular according to one of claims 1 to 5, which is designed to carry out a method according to one of claims 6 to 10, or in which a computer program according to claim 11 is stored in a manner suitable for execution.

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