EP1003969B1 - Two-cylinder thick matter pump - Google Patents

Abstract

A two-cylinder thick-matter pump for continuous delivery of thick matter is characterized in that a reversing valve (5) has a diverter housing (8, 8') with at least four openings (a-b), the diverter (6, 6') disposed in the diverter housing (8, 8') is swiveled with its outlet opening in front of the cylinder openings and has an inlet opening (RE) which is firmly connected with the suction pipe (3), the cavity (H) in the diverter housing (8, 8') being constantly under delivery pressure, and at least one shut-off element (10) being provided for closing the suction pipe (3) and/or the first and/or second openings (a , b) of the diverter housing (8, 8').

Description

The invention relates to a two-cylinder slurry pump according to the Preamble of claim 1.

Two-cylinder thick matter pumps consist of two single pumps interconnected in terms of circuitry and in their movement are synchronized so that when pumping one Cylinder (Z1) the other cylinder (Z2) performs a suction stroke. The stroke speeds of the pistons are usually in the two cylinders the same, so that the temporal ends of the cylinder strokes (Suction stroke and pump stroke) coincide. At the end of each Hubes the direction of movement of the cylinder pistons is reversed, so that there is a constant change between pumping and suction strokes he follows.

The suction stroke is used to remove thick matter such as concrete from a prefill container to promote the respective suction cylinder. In the following Pump current is the previously sucked material from the now pumping cylinder pressed into the delivery line. In order to this process is always done in the correct way, are common one or more control elements or changeover valves - for example Pipe switches or flat slide - provided, which itself move back and forth between two switching positions to the correct connection between the cylinder openings, the Connect the delivery line and the pre-fill tank.

Pipe switches as currently the most common control units are generally. arranged so that they go between two switching end positions are pivotable in which they have the necessary connection between the cylinder openings, the delivery line connection and the prefill container. The pipe switch is included one end constantly connected to the delivery line while the other end each the cylinder opening of the pumping straight Cylinder covered. The cylinder opening of the suction cylinder stands thus open to the prefill container.

Because the reversing process of the pipe switch from a cylinder opening on the other hand, the flow rate cannot be as fast as desired interrupted in the delivery line when changing the stroke. from that inevitably follows a discontinuity in the flow problematic consequences such as acceleration shocks, shocks, high mechanical loads on the components, vibrations of a connected placing boom, increased wear, etc.

The flow interruptions can have further negative effects extend further. For example, the effect often occurs that the sucked thick matter compressible due to an air or gas content is. With the start of the pump stroke, the thick material must then first pre-compressed to the operating pressure in the delivery line before the flow begins. Depending on the type of Concrete and depending on the other operating conditions but the need for pre-compression can also be neglected be small.

Another type of flow interruption is particularly problematic. This is caused by the fact that the pipe switches the type and arrangement described above in their Switching movement in the middle position of the feed cylinder openings do not completely cover at the same time (this effect is called negative Overlap). The can in the delivery line under Pressure and tensioned thick matter in the with not yet compressed thick material filled cylinder or at the opening flow back into the prefilling container (this effect is called Referred to as "short circuit").

Overall, the effects described above lead to one considerable time interruption of the flow in the Delivery line and through the backflow from the delivery line possibly also to a significant reduction in the output. One can reduce the adverse effects by accelerating the Reduce the switching movement, but do not switch it off completely.

There is therefore a desire to interrupt the flow to avoid and continuously promote the concrete. From the Several approaches to this are already state of the art known, but either are insufficiently functional or mean a construction expense that is no longer justifiable, which makes the pumps too expensive and uneconomical.

According to an idea, the piston speeds in the delivery cylinders dimensioned differently, e.g. becomes the suction speed chosen so much larger than the pumping speed that the Suction stroke is ended so early that in the remaining time until At the end of the pump stroke, the pipe switch is swiveled up to can be used for the middle position between the two cylinders. Several phases are run through, the first of which is the cylinder opening of the cylinder that previously sucked by means of a Shut-off element is closed, so that the under pressure Do not flow standing concrete back into the pre-fill container at any stage can. By closing the cylinder opening is also a pre-compression of the thick matter in the cylinder on the operating pressure in the delivery line possible. In a Another swing phase is the opening of the previously sucking Cylinder, while the pump stroke of the other cylinder, also connected to the delivery line. In this position (pump standby position) remains with the precompressed thick matter filled cylinders to the end of Pump strokes and then starts without time delay and without pressure drop in the delivery line, in turn, the pump stroke, while the First opening of the previously pumping cylinder in a third Phase is closed by means of a further shut-off element (to avoid a short circuit). In a fourth and last Phase, the opening of this cylinder to the prefill container is released and the cylinder or piston of this cylinder begins its suction stroke, again at a higher speed than that of the running pump stroke. Closes at the end of the suction stroke with the pump stroke still running in the opposite direction a new switching process of the pipe switch.

According to another solution described in DE PS 29 09 964 the applicant will use each feed cylinder to control the Suction and pump current while avoiding backflow and each with its own pipe switch while enabling pre-compression assigned. This prevents one as a shut-off element on the side formed on the inlet opening of the diverter valve Backflow and enables the pre-compression stroke. The exit ends the pipe switches lead into a downpipe, the Outlet is connected to the delivery line. This pump is especially with regard to their width, the construction effort (two pipe switches, i.e. twice the cost of materials) and energy consumption (double energy expenditure for the two rotary actuators the pipe switches) in need of improvement.

The control is proposed in the generic US Pat. No. 3,663,129 the thick matter flow of a continuously pumping two-cylinder thick matter pump can be realized with just a single pipe switch. In contrast to DE PS 29 09 964, the pump of US 3,663,129 although only one pipe switch through which the pressure flow flows, however, their oversized entrance opening is problematic. It extends in an oblong hole over the arch of the Swivel radius and must have a length that is at least that corresponds to three times the diameter of the feed cylinder openings since in an intermediate phase (pump ready position of the cylinder, the has previously sucked) connected both cylinders to the delivery line have to be.

The high occurring at the usual high operating pressures Forces can be applied to this pipe switch and the pipe switch Pre-fill container not at all or only if the wall thickness is extremely thick take up. This is made worse by the fact that due to the required short swiveling times over the long ones Switching paths result in very high inertia forces and moments. Also statically speaking, this is due to the large wall thickness Additional weight of the mostly mobile pumps as well as the high costs unacceptable.

The invention therefore aims to be a continuously promoting Two-cylinder thick matter pump with little design effort to accomplish.

The invention achieves this aim by the subject matter of the claim 1.

The continuously promoting known from the prior art Thick matter pumps have in common that their development has been around for a long time has remained, the pipe switch in the usual way in Arrange the bottom area of the prefill container and the pipe switch assign the function to the pump (pressure) flow from the cylinders to lead to the delivery line. The invention is surprising here another way, because it arranges the pipe switch between the suction side of the feed cylinder and the suction line and separates the prefill container functionally from the pipe switch housing. The invention thus realizes a simple and compact Pipe switch to control a continuous flow of thick matter. So the pipe switch according to the invention requires the cylinder openings on it brushing end with only a circular opening the diameter of the suction line.

The invention also provides a particularly compact arrangement, where the diverter in a very small separate housing is arranged, which has a "minimal" geometry, so to speak, in which the side lengths of the housing are only slightly longer than the diameter of the line and cylinder openings. The Housing is under constant pressure, with the cavity between the outer contour of the pipe switch and the inner contour of the Housing acts simply as a pressure line and the connects each pumping cylinder to the delivery line.

In contrast to the generic state of the art (US 3,663,129), the pipe switch is not on the pump side but on the suction side arranged. This creates compared to the generic state technology no longer has the problems of oversized design the pipe switch outlet due to the high pressures in the Tube.

From DE AS 16 53 614 it is known, one the thick material to arrange controlling pipe switch in a separate housing, the pipe switch the thick matter flow (suction flow) from the prefill leads to the cylinders. However, that is in this document The pump shown is not suitable for continuously adding thick matter promote. To understand this better, let's start with the Swiss one Patent application CH 8986/61 or US 3 146 721 mentioned which represent the prior art, which improve the DE AS 16 53 614 want. The CH 8986/61 describes a hydraulic piston pump to convey viscous, pulpy or plastic masses. The piston pump comprises a cylindrical valve spool with two arcuate channels, which by twisting the material inlet and the material outlet alternately with one of the feed cylinders connect. The flow of material comes inevitably currently comes to a standstill when the valve spool is in a Intermediate position.

DE AS 1653 614 wants this state of the art improve that they have a rotary valve for a slurry pump creates, where it is not temporarily interrupted of the material flow comes. This achieves the solution of the DE AS 1 653 614 through a cup-like valve housing with three openings in the side wall and through a cup-like valve body, whose bottom part is close to the bottom part of the valve housing and has two wings. The cup-like valve body connects a pre-fill container to one of the cylinders. It is the widest in the cup-like valve body Senses around a "pipe switch" arranged on the suction side. Is prevented with this switch only that the material under pressure in the event of synchronism between valve spool and Delivery cylinder (at that time apparently still a control technology Problem) currently stands still because the material outlet remains constantly open. Continuous pumping, however, is not possible is not mentioned anywhere in the scriptures. For example it is clear in knowledge of the present invention that the suction side the valve of DE 1 653 614 a shut-off element for prevention of backflow is absent.

The present invention provides the generic thick matter pump on the other hand with a changeover valve, the pipe switch on the suction side connected and with it a continuous pumping is feasible. Among other things, this is due to the additional Shut-off element for closing the suction line and / or the first and / or second openings of the diverter housing with which can reliably prevent thick matter from entering the suction line or can even flow back into the prefill container. This measure is just not known from DE 1 653 614.

Another problem of DE 1 653 614 is the fact that the valve shown is heavy and extremely expensive. Also for this reason the idea of DE 1 653 614, i.e. the Thought of a pipe switch on the suction side, never to realize one continuously pump.

By combining the features of claim 1 is against a very compact changeover valve can be realized, its geometric Dimensions are amazingly minimizable. This is because among other things, that on the shut-off elements of the changeover valve there are no excessive pressure differences, which these Excessive stress on components. During switching ideally occur even at the shut-off elements no pressure differences.

To control the pump or its valve, this is preferred at the beginning mentioned methods used, i.e. the piston speeds in the delivery cylinders are dimensioned differently and the suction speed becomes so much greater than the pump speed chosen that the suction stroke is ended so early that in the remaining time until the end of the pump stroke, the swiveling the pipe switch can use. Doing so again go through several phases. For a more detailed explanation, please refer to the Figure description referenced.

Advantageous variants of the invention are in the subclaims specified.

Fig. 1a und b

verschiedene Ansichten eines Umschaltventiles eines ersten Ausführungsbeispiels der Erfindung mit L-förmiger Rohrweiche;

Fig. 2a bis d

verschiedene Phasen des Schaltzyklus des Umschaltventiles aus Fig. 1;

Fig. 3a und b

verschiedene Ansichten eines Umschaltventiles eines zweiten Ausführungsbeispiels der Erfindung mit L-förmiger Rohrweiche;

Fig. 4a bis d

die vier verschiedenen Phasen des Schaltzyklus des Umschaltventiles aus Fig. 3;

Fig. 5a bis c

verschiedene Ansichten eines Umschaltventiles eines dritten Ausführungsbeispiels der Erfindung mit S-förmiger Rohrweiche;

Fig. 6a bis d

die vier verschiedenen Phasen des Schaltzyklus des Umschaltventiles aus Fig. 5;

Fig. 7a bis c

verschiedene Ansichten eines Umschaltventiles eines vierten Ausführungsbeispiels der Erfindung mit S-förmiger Rohrweiche;

Fig. 8a und b

zwei Phasen des Schaltzyklus des Umschaltventiles aus Fig. 7.

The invention is described in more detail below using exemplary embodiments with reference to the drawing. Show it:

1a and b

different views of a switch valve of a first embodiment of the invention with an L-shaped diverter;

2a to d

different phases of the switching cycle of the switching valve from Fig. 1;

3a and b

different views of a switching valve of a second embodiment of the invention with an L-shaped diverter;

4a to d

the four different phases of the switching cycle of the switching valve from Fig. 3;

5a to c

different views of a switch valve of a third embodiment of the invention with S-shaped diverter;

6a to d

the four different phases of the switching cycle of the switching valve of Fig. 5;

7a to c

different views of a switch valve of a fourth embodiment of the invention with S-shaped diverter;

8a and b

two phases of the switching cycle of the changeover valve from FIG. 7.

First of all, let's look at the construction of the four different exemplary embodiments 1, 3, 5 and 7 described.

Fig. 1 shows a section of a two-cylinder thick matter pump for continuous conveyance of thick matter, especially for continuous Conveying concrete (dotted), which two (only partially shown here) delivery cylinders 1, 2 for delivery of concrete from a suction line 3 into a delivery line 4 having.

Between the delivery cylinders 1, 2, the suction line 3 and the delivery line 4, a changeover valve 5 with a pipe switch 6 is connected. The switching valve 5 has a separate - i.e. its own, from the pre-fill container 7 structurally separate - pipe switch housing 8 with at least four openings a, b, c, d, the first and the second opening a and b to the first and the second feed cylinder 1, 2, the third opening c to the suction line 3 and the fourth opening d is connected to the delivery line 4. The pipe switch housing 8 also has a stepped base part 81, in which the third opening c is recessed and into which the suction line 3 opens, a subsequent cylindrical base body 82, in the peripheral wall of which the openings a and b are recessed, and a conical lid portion 83 in which the opening d is recessed and to which the delivery line 4 is connected.

The inlet opening RE (in the direction indicated by the arrow S Flow direction of the concrete) of the L-shaped pipe switch 6 opens in third opening c of the switch gate housing 8 and is fixed to the Suction line 3 connected. The outlet opening RA of the pipe switch 6 is, however, between the first and second openings a, b to Connection of the delivery cylinders 1, 2 (or these upstream pipe sections) pivotable. For the purpose of pivoting is one Drive shaft 9 is provided, to which a (not shown) Drive unit can be connected. Between the pipe switch outer wall x and the housing inner wall y is a Cavity H formed, which acts as a pressure line between the each pumping delivery cylinder 1, 2 and the delivery line 4 is used and which is constantly under pressure during pumping.

An arc piece 11 with two arcuate extensions 12, 13 on both sides the diverter outlet opening RA is such to the diverter 6 integrally formed that a shut-off element 10 forms, which at Twisting the pipe switch 6 on the inner wall of the cylindrical Section 82 abuts and also the outlet openings a or b to Release or close connection of cylinders 1, 2.

1 differs from the embodiment of FIG Fig. 3 essentially in that instead of the elbow 11 as Shut-off element, a gate valve 14 is arranged in the suction line 3 is. The slide 14 represents another constructive and structural Simplification of the invention because it eliminates the need to form the elbow 11. Also the seal the slide 14 turns out to be less complicated than the seal of the bow piece 11.

It is also only necessary to operate the slide 14 separately to be able to generate and control signals, which accordingly close the slide 14 during the individual phases of pumping and to open. However, this does not represent the precision of modern controls another problem. Since the slide 14 only in its switching end positions Switching is also subject to pressure differences of the slide 14 without a pressure difference as problem-free.

The use of the slide 14 results in a further one constructive advantage. This follows from the fact that the diverter 6 with a flat cover 84 instead of the conical cover 83 from FIG. 1 can be provided, because also with the flat lid 84, in which the opening d for connecting the delivery line 4 recessed there is now enough flow space for the concrete in the cavity H. This space takes up in the embodiment of Fig. 1 partially the bow piece 11. The embodiment of Fig. 3 may be the optimal one for a variety of concrete types Realization of the invention because the pipe switch housing 8 and the diverter 6 are to a minimal size (in the area the pipe diameter) and few uncomplicated components limited.

Fig. 5 shows an embodiment analogous to Fig. 1, in which however, instead of an L-shaped diverter 6, an S-shaped one Pipe switch 6 'is used. This diverter 6 'is at different types of concrete preferred, because in it different flow conditions prevail than in the more curved L-shaped crossover 6. Corresponding to the S-shape of the diverter 6 'here is that Pipe switch housing shaped: it almost fits the S shape in its Outer contour on and tapers from a flat cover section 801 from in the area of a quasi "conical" housing section 802. In the cover section 801, the openings a, b are recessed and in Housing section 802 are the openings c and d for the delivery line intended. At its opposite the cover section 801 At the end, section 802 tapers to the outside diameter the pipe switch or the diameter of the opening d for connection the suction line 3. The lid section 801 is used by several (e.g. 10 or more) ribs 15 which stabilize between the lid portion 801 and the drive shaft 9 are formed.

Similar to FIG. 1, a shut-off element in FIG. 5 is again used "Arch piece" 11 '(see also Fig. 6), which here as a flat Disc arch is formed and in turn on both sides of the Pipe switch outlet opening RA has extensions 12 'and 13'. The Drive shaft 9 in turn rotates the diverter 6 and that molded elbow piece 11 '.

The embodiment of FIG. 7 corresponds in its structure largely the embodiment of FIG. 5, because it will again an S-shaped pipe switch was used. Similar to FIG. 3 but is instead of an arch element 11 'as a shut-off element again the gate valve 14 is arranged in the suction line 3. It there are again the advantages of saving a more complex Shut-off element in an arch shape and easier sealing.

The mode of operation of the pump according to the invention is described below 2, 4, 6 and 8 will be explained. It is up first 2 and 6, which (as on the other hand Fig. 4 and 8) with respect. the course of their switching cycles are analogous to each other.

The operation of the concrete pump or the changeover valve takes over the idea of different piston speeds of the sucking and the pumping delivery cylinder 1, 2. The Suction speed, in turn, so much greater than that Pump speed selected so that the suction stroke is ended so early that already in the remaining time until the end of the pump stroke the pivoting of the diverter 6 can begin.

The four main phases or steps of switching are special can be clearly seen in FIG. 6. In the first phase (Fig. 6a) Cylinder opening of the delivery cylinder 2 (previously a suction stroke had already carried out) from an extension 12 'of the arch piece 11 'covered, the pipe switch outlet opening RA is from Cover section 801 closed. This prevents that the concrete from the cylinder 2 into the suction line 3 or Pre-fill container 7 can flow back. By closing the Cylinder opening b also pre-compresses cylinder 2 located thick matter on the prevailing in the delivery line 4 Operating pressure possible. The other cylinder is pumping still thick matter through the pipe switch housing 8 in the delivery line 4th

Then the pipe switch turns into a position (Fig. 6b), in which both feed cylinders 1 and 2 with the inside of the switch gate housing are connected. The pump stroke of cylinder 1 is running still while the cylinder 2 with its pre-compressed content rests and in that its opening to the cavity H is released is in a pump standby position; the suction line 3 remains locked, because the pipe switch lies with its cylindrical Outlet opening RA on cover 801.

In a third step, the delivery cylinder 2 starts from its pump-ready position without time delay and without pressure drop in the delivery line 4 in turn the pump stroke, while the opening a of the previously pumping cylinder 1 in the third phase by means of Extension 13 'of the shut-off element 11' is closed (Fig. 6c). The pipe switch outlet opening is also still closed.

In a fourth and final phase, the opening of the cylinder 1 released to the suction line 3 or to the prefill container 7 and the Piston of the feed cylinder 1 begins its suction stroke, namely again at a higher speed than that of the current one Pump strokes (see Fig. 6d). At the end of the suction stroke follows with the pump stroke still running in the opposite direction Another switching process of the diverter 6 in the analog to Fig. 6a Position in relation to the feed cylinder 1.

When operating the design variants with gate valves 14 instead of elbows 11 and 11 'there is only the difference, that the gate valve 14 closes with step one (Fig. 4a, first phase), while step two and three remain closed (Fig. 4b and 4c, second and third phases) and with the last and fourth step opens again during the suction phase (Fig. 4d, fourth Phase).

LIST OF REFERENCE NUMBERS

delivery cylinders

1, 2

suction

3

delivery line

4

switching valve

5

diverter

6, 6 '

pre-fill

7

Diverter housing

8, 8 '

drive shaft

9

shut-off

10

elbows

11, 11 '

Elbow-extensions

12, 13, 12 ', 13'

Gate valves

14

ribs

15

openings

a, b, c, d

Diverter outer wall

x

Housing inner wall

y

Direction of flow (suction)

S

cavity

H

Pipe switch inlet opening

RE

Diverter opening

RA

Elements of various pipe switch housings: stepped bottom part

81

cylindrical body

82

conical lid section

83

flat lid

84

cover section

801

housing section

802

Claims (15)

1. Two-cylinder slurry pump for continuously delivering a slurry, particularly for continuously delivering concrete, which has two delivery cylinders (1, 2) for delivering the slurry from a suction line (3) into a delivery line (4) and a switchover valve (5) with a pivotable distributor sleeve (6, 6') for switching between the first and second delivery cylinders (1, 2), wherein

   a) the switchover valve (5) has a distributor sleeve housing (8, 8') with at least four openings (a - d), the first and second openings (a, b) being connected to the first and second delivery cylinders (1, 2), respectively, the third opening (c) being connected to the suction line (3) and the fourth opening (d) being connected to the delivery line (4),

   b) the distributor sleeve (6, 6') disposed in the distributor sleeve housing (8, 8') has an inlet opening (RE), which communicates with the third opening (c) in the distributor sleeve housing (8, 8') and is always connected to the suction line (3) and an outlet opening (RA), which is pivotable between the first and second openings (a, b) for connecting the delivery cylinders (1, 2),

   c) defined between the distributor sleeve outer wall (x) and the distributor sleeve inner wall (y) there is a space (H), which constitutes the pressure line between the currently pumping delivery cylinder (1 or 2) and the delivery line (4),
   characterised in that

   d) at least one closure element (10, 14) is provided for closing the suction line (3) and/or the first and/or second opening (a, b) in the distributor sleeve housing (8, 8') so that the space (H) is constantly under delivery pressure.
2. Two-cylinder slurry pump as claimed in Claim 1, characterised in that the distributor sleeve (6) is constructed in the form of an L pipe.
3. Two-cylinder slurry pump as claimed in Claim 2, characterised in that the distributor sleeve housing (8) has a substantially cylindrical section (82), which is closed by a flat or conical cover (83, 84).
4. Two-cylinder slurry pump as claimed in Claim 3, characterised in that the first and second openings (a, b) are hollowed out in the wall of the cylindrical section (82) and that the third and fourth openings (c, d) are hollowed out in the opposing cover sections (81 and 83 or 84).
5. Two-cylinder slurry pump as claimed in Claim 1, characterised in that the distributor sleeve (6') is constructed in the form of an S pipe.
6. Two-cylinder slurry pump as claimed in Claim 5, characterised in that the housing has a housing section (802), which is substantially matched to the S shape of the distributor sleeve and is of nearly conical shape and which is closed by a flat cover section (801).
7. Two-cylinder slurry pump as claimed in Claim 6, characterised in that the housing section (802) tapers at its end opposite to the cover section (801) down to the outer diameter of the distributor sleeve (6') or the diameter of the opening (d) for connection of the suction line (3).
8. Two-cylinder slurry pump as claimed in Claim 6 or 7, characterised in that the cover section (801) is stabilised by a plurality of ribs (15), which are formed between the cover section (801) and drive shaft (9).
9. Two-cylinder slurry pump as claimed in one of Claims 5 to 8, characterised in that the first and second openings (a, b) are hollowed out in the cover section (801) and that the third and fourth openings (c, d) are hollowed out in the housing section (802).
10. Two-cylinder slurry pump as claimed in one of the preceding claims, characterised in that at least one of the closure elements (10) is constructed in the form of an arcuate member (11), which, on both sides of the cylindrical outlet opening (RA) in the distributor sleeve (6, 6') has arcuate extensions (12, 13), which are so constructed that they can close the first and/or second openings (a, b).
11. Two-cylinder slurry pump as claimed in Claim 10, characterised in that the arcuate member (11) is formed on the distributor sleeve outer wall (x) so that it rotates when the distributor sleeve rotates.
12. Two-cylinder slurry pump as claimed in Claim 10 or 11, characterised in that the arcuate member (11) engages the distributor sleeve inner wall (y) with a disc-like or cylindrical surface.
13. Two-cylinder slurry pump as claimed in one of Claims 1 to 9, characterised in that at least one of the closure elements (10) is constructed to close the suction line (3).
14. Two-cylinder slurry pump as claimed in Claim 13, characterised in that the closure element is a gate-type shut-off valve (14).
15. Two-cylinder slurry pump as claimed in one of the preceding claims, characterised in that the distributor sleeve housing (8, 8') is spatially separated from a feed container (7).

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