EP1419316B1 - Method for controlling a thick matter pump - Google Patents

Abstract

A method for controlling a thick matter pump comprising two delivery cylinders ( 10 ) emerging, via two openings ( 12 ), into a material reservoir ( 14 ), associated with two delivery pistons ( 26 ), symmetrically synchronized relative to said cylinders, and a branch pipe 18 arranged inside the material reservoir ( 14 ), capable of being connected, on the input side, alternatively to one of the openings of the delivery cylinders with exposing of the other opening, the output side connected to a conveyance conduit ( 20 ). When the pumping is interrupted, thick matter, liquid concrete for example, is sucked up, via the delivery cylinder temporarily communicating with the reservoir, and is delivered, via the other cylinder ( 10 ), connected to the branch pipe ( 18 ), so as to form a column of thick matter through the delivery pipe ( 20 ), towards its output. In order to avoid problems of deposit, condensation and solidification, the invention is characterized in that the thick matter column is maintained, at least temporarily, in movement, when pumping is interrupted, in the delivery pipe ( 20 ) and/or the branch pipe ( 18 ) and/or the delivery cylinders ( 10 ), while not allowing the thick matter to escape from said delivery pipe ( 20 ) on the output side. The invention is further characterized in that, when the pumping is stopped, the thick matter in the matter reservoir is maintained in movement by the back and forth oscillation of the feeding pipe ( 18 ) and/or at least one stirrer ( 34 ).

Description

The invention relates to a method for controlling a sludge pump, the two opening via openings in a material feed container delivery cylinder with push-pull actuated delivery piston and arranged within the material feed container, the inlet side alternately connectable to the openings of the delivery cylinder and the other opening releasing, outlet side with a delivery line connected diverter has sucked in which thick matter material during pumping operation over the currently open to the material feed container open the delivery cylinder and the other currently connected to the transfer tube delivery cylinder is supported by building a column of high-solids through the feed line to its outlet.

Although thick matter pumps of this type are suitable for conveying any pumpable thick matter, they have a special technical and economic importance in the promotion of liquid concrete. The following explanations therefore refer, by way of example, to the production of liquid concrete, without any restriction being made therein.

Slurry pumps can be arranged on stationary or mobile racks. Especially in mobile concrete pumps, the delivery line is usually guided over a trained as a kink mast distributor boom and has in the region of its outlet on a hose end. The material feed container of the concrete pump is usually fed via concrete mixer with liquid concrete. During the waiting time for the next truck mixer or when the distributor boom is aligned with another discharge point, there are always pumping pauses in which the concrete pump is stationary. It must be remembered that dormant liquid concrete tends to settle and solidify. This is especially true for self-compacting Concretes in which due to the outgassing of air pores self-compression builds up from below. In the pumping breaks, therefore, both in the line system and in the material feed container undesirable solidification phenomena occur in the concrete.

In a method of the type specified in the introduction, it is known per se (DE-A-2039854 and DE-A-2161025) to keep the thick matter column in the delivery line and / or the pipe switch and / or the delivery cylinders at least temporarily in motion during a pumping pause by the diverter valve in any position, eg half open, blocked, so that the delivery pistons continue to run and keep the concrete moving without promotion.

The invention has for its object to further develop the known method for controlling a sludge pump so that an undesirable solidification of the thick material during pumping breaks is avoided.

To solve this problem, the feature combinations specified in claims 1, 10 and 11 are proposed. Advantageous embodiments and modifications of the invention will become apparent from the dependent claims.

The solution according to the invention is based on the idea known per se that the solidification of preferably self-compacting thick matter, such as liquid concrete, can be avoided by keeping the thick material in motion even during the pumping pauses. Accordingly, during a pumping break, the thick matter column in the delivery line and / or the pipe switch and / or the delivery cylinders is kept in motion at least temporarily, without thick matter leaving the delivery line on the outlet side. This is achieved by actuating the delivery pistons and / or the diverter valve during the pumping pause to produce an alternately reciprocating column of thick matter. The Main amount of the thick material can remain in this procedure until the next pumping phase in the delivery line system. Even with longer waiting times, no emptying of the delivery line is required.

• dass zu Beginn einer Pumppause aus einer momentanen Stillstandsstellung heraus zunächst Dickstoffmaterial im Rückwärtshub des Kolbens des momentan an die Rohrweiche angeschlossenen Förderzylinders aus der Förderleitung angesaugt wird,
• dass im Anschluss an den ersten Rückwärtshub die Rohrweiche auf den anderen Förderzylinder umgeschaltet und Dickstoffmaterial im Rückwärtshub von dessen Kolben aus der Förderleitung angesaugt wird,
• dass im Anschluss an den letzten Rückwärtshub die Rohrweiche auf den jeweils anderen Förderzylinder umgeschaltet und Dickstoffmaterial im Vorwärtshub von dessen Kolben in die Förderleitung gedrückt wird, ohne dass es auslassseitig aus der Förderleitung austritt.

In order to ensure that the majority of the thick material remains in the conveyor system, it is proposed according to the invention,

• that at the beginning of a pump break from a current standstill position initially thick material is sucked in the return stroke of the piston of the currently connected to the pipe switch conveyor cylinder from the feed line,
• that, following the first backward stroke, the diverter switch is switched to the other delivery cylinder and high-viscosity material is sucked out of the delivery line in the return stroke by its piston,
• that after the last backward stroke, the pipe switch is switched to the respective other delivery cylinder and thick matter material is forced in the forward stroke of the piston in the delivery line, without it exits the discharge line from the delivery line.

• wenn im Anschluss an den ersten Vorwärtshub die Rohrweiche auf den jeweils anderen Förderzylinder umgeschaltet und Dickstoffmaterial im Vorwärtshub von dessen Kolben in die Förderleitung gedrückt wird, ohne dass es auslassseitig aus der Förderleitung austritt,
• wenn im Anschluss an den letzten Vorwärtshub ohne Umschaltung der Rohrweiche Dickstoffmaterial im Rückwärtshub aus der Förderleitung angesaugt wird, und/oder
• wenn die vorstehenden Bewegungsabläufe während der Pumppause nach Art einer zyklischen Folgesteuerung wiederholt werden.

It is also advantageous

• if, following the first forward stroke, the diverter switch is switched to the respective other delivery cylinder and thick matter material is forced in the forward stroke of its piston into the delivery line, without it leaving the delivery line on the outlet side,
• if after the last forward stroke without switching the pipe switch thick matter material is sucked in the return stroke from the feed line, and / or
• when the foregoing motions are repeated during the pumping pause in the manner of cyclic sequencing.

The forward and reverse strokes performed during the pumping pause may extend over a portion as well as over the entire length of the cylinder. Basically, it is possible to perform several reverse and forward strokes in a row without switching the pipe switch. The outlet end of the delivery line should be raised at the beginning of each pump break so far that no thick material under the influence of gravity can escape the outlet side.

In order to avoid self-compression or solidification of the thick material in the material feed container, it is proposed according to a further advantageous embodiment of the invention that during the pumping pause the high-viscosity material in the material feed container by the reciprocating diverter and / or at least one agitator is kept in motion. The direction of rotation of the agitator located in the material feed container can be reversed periodically or stochastically, preferably in response to the piston strokes. In principle, it is possible for additional agitators, which engage in the material feed container, to be switched on during the pumping pause, preferably with an alternating direction of rotation.

In the event that during the pumping pause little or no thicker material is in the delivery line, a simplified mode of movement according to the invention can be achieved by the transfer tube is pivoted in the pumping pause in a middle position with partial overlap between the two cylinder openings, and that the piston preferably be controlled slower than the pumping operation in push-pull. Thus, an effective circulation of the thick material in the material supply container and in the delivery cylinders can be achieved without causing a flow in the distribution boom.

Basically, it is possible according to the invention, the thick material in the feed line and in the pipe switch with mechanical means in motion to keep. This can take place in that during the pumping pauses an agitating element is introduced into the delivery line via a spring-elastic shaft or a propeller shaft and pushed by means of an external drive in the delivery line or is driven in rotation. Before a new start of pumping, the stirrer can be removed again from the delivery line.

In the following the invention will be explained in more detail with reference to the embodiment shown schematically in the drawing.

The single figure shows a two-cylinder concrete pump in a partially sectioned perspective view.

The concrete pump shown in the drawing consists essentially of two delivery cylinders 10, the end-side openings 12 open into a material feed container 14. In the material feed container 14 engages a diverter 18, which is connected on the inlet side alternately connected to the openings 12 of the delivery cylinder and outlet side connected to a feed line 20. The delivery pistons 26 arranged in the delivery cylinders 10 are driven in push-pull fashion via hydraulic drive cylinders 24 ', 24 "For this purpose, the delivery pistons 26 are connected via a common piston rod 28 to the drive pistons 30 of the drive cylinders 24', 24". In the area between the delivery cylinders 10 and the drive cylinders 24 ', 24 "is a water tank 32 through which the piston rods 28 pass.

During pumping operation, liquid concrete is sucked in via the delivery cylinder 10 that is currently open to the material feed container 14 (arrow 22), and conveyed via the other delivery cylinder connected to the transfer tube 18 with the construction of a concrete column through the delivery line 20 to its outlet (arrows 16).

During pumping breaks, z. B. while waiting for the next truck mixer, it may lead to solidification or deposition of concrete components in the overall system. This is especially true for self-compacting Emphasize in which, due to the outgassing of air pores, the concrete condenses from below. This undesirable effect can be avoided if the entire volume of concrete in the machine is kept moving even during the pumping pauses. This can be done by a suitable control of the concrete pump during the pumping pauses, which can be triggered by the Pumpenmaschinist example of his Femsteuerung. The movement mode to be set in this manner during the pumping breaks provides that the concrete column in the delivery line 20 and / or the pipe switch 18 and / or the delivery cylinders 10 is at least temporarily kept in motion without liquid concrete exiting the delivery line 20 on the outlet side. This can be done by actuating the delivery pistons 26 and / or the diverter valve 18 during pumping pauses to produce an alternately reciprocating concrete column. Furthermore, during the pumping pauses, the liquid concrete can also be kept in motion in the material feed container 14 by the reciprocating diverter 18 and / or at least one agitator 34.

Embodiment 1

The movement mode according to embodiment 1 provides that at the beginning of a pump break from a current standstill position first concrete in the backward stroke of the piston 26 of the currently connected to the transfer tube 18 the delivery cylinder 10 is sucked from the delivery line 20. Following this first backward stroke, the pipe switch 18 is switched to the other delivery cylinder 10 and also sucked concrete in the return stroke of the piston 26 from the delivery line 20. Subsequent to the last backward stroke, the transfer tube 18 can then be switched to the respective other delivery cylinder 10 and concrete in the forward stroke of the piston into the delivery line 20 are pressed. Subsequent to the first forward stroke, the transfer tube can be switched to the other delivery cylinder and the concrete in turn be pressed in the forward stroke of the piston in the delivery line. The two initial backward strokes ensure that at the next forward strokes no concrete outlet side exits the delivery line. To ensure this also in the subsequent strokes, 18 concrete is sucked in the return stroke from the delivery line after the last forward stroke without switching the diverter. The backward and forward stroke can be repeated 18 times without switching the diverter pipe. The above movement sequences can be repeated during the entire pump break in the manner of a cyclic sequencing, without causing an outlet-side outlet of concrete and excessive filling of the material feed container comes. The constant movement of the concrete volume ensures that the concrete can not solidify or compact during the pumping pauses.

Embodiment 2

When operating concrete pumps, it often happens that although liquid concrete is still in the material feed tank, the feed line and the diverter valves are already cleaned and free of concrete. In this case, it is important that the concrete contained in the material supply container and in the delivery cylinders is kept in motion without the concrete entering the delivery line via the transfer tube. To achieve this, it is proposed according to the simplified mode of movement according to Embodiment 2, that the pipe switch is pivoted in the pumping pause in a middle position with partial overlap between the two cylinder openings and that the piston, while maintaining a movement in the concrete preferably slower than the pumping operation in push-pull become. As a result, the concrete is rolled back and forth on the delivery cylinder in the hopper, without causing undesirable concrete flow in the delivery line.

Embodiment 3

To maintain a concrete movement within the delivery line, it is also possible in principle to introduce a mechanical stirring element into the delivery line. For this purpose, a suitable opening to be provided on the delivery line, via which the stirring element can be introduced, for example via a propeller shaft or a resilient shaft. An external drive then ensures that the stirring member is moved either rotationally or axially oscillating, so that a movement is introduced into the dormant concrete column. With a new start of pumping the stirrer is then pulled out of the line again.

In summary, the following should be noted: The invention relates to a method for controlling a slurry pump. The sludge pump has two opening via openings 12 into a material feed container 14 delivery cylinder 10 with push-pull actuated piston 26 and disposed within the material feed container 14, the inlet side alternately connectable to the openings of the delivery cylinder and the other opening releasing, exit side connected to a feed line 20 diverter 18 on. When pumping is on the currently open to the material feed container delivery cylinder thick material such. B. liquid concrete sucked and conveyed through the other, connected to the transfer tube 18 delivery cylinder 10 under construction of a thick matter column through the feed line 20 through to the outlet. In order to avoid settlement phenomena, densifications and solidifications in the high-viscosity material, it is proposed according to the invention that the high-solids column is kept at least temporarily in motion during a pumping break in the delivery line 20 and / or the pipe switch 18 and / or the delivery cylinders 10, without thick matter material exits the delivery line 20 on the outlet side. Next, the invention provides that during the pumping break and the thick material in the material feed container by the reciprocating diverter 18 and / or at least one agitator 34 is kept in motion.

Claims (13)

1. Process for controlling a thick matter pump, including two conveyor cylinders (10) communicating via openings (12) with a material reservoir (14) and with conveyor pistons (26) operated in counterstroke, as well as a pipe branch (18) provided within the material reservoir (14) connected on the inlet side alternative with one of the openings (12) of the conveyor cylinders with freeing of the respective other opening and on the outlet side connected with a conveyance conduit (20), in which thick matter, preferably liquid concrete, is suctioned in during pump operation through the conveyor cylinder (10) which is open at the time towards the material reservoir (14) and is conveyed through the other conveyor cylinder (10) which is connected to the branch pipe (18) and through the conveyance conduit (20) with building up of a thick matter column towards the outlet thereof, wherein during a pausing of pumping the thick matter column in the conveyance conduit (20) and/or the branch pipe (18) and/or the conveyor cylinders (10) is at least temporarily maintained in motion by operating the conveyor piston (26) and/or the branch pipe (18) for producing an alternating back and forth movement of the thick matter column, without thick matter exiting from the outlet side of the conduit (20), thereby characterized, that at the onset of pausing of pumping, starting with a temporarily resting condition, first thick matter is suctioned out of the conveyance conduit (20) by a backwards stroke of the piston (26) of the conveyor cylinder (10) connected at this time with the branch pipe (18), that subsequent to the first backwards stroke the branch pipe (18) is switched over to the other conveyor cylinder (10) and thick matter is suctioned out of the conveyance conduit (20) by a backwards stroke of its piston (26) and that subsequent to the last backwards stroke the branch pipe (18) is switched over to the respective other conveyor cylinder (10) and thick matter is pressed into the conveyance conduit (20) by a forwards stroke of its piston, without matter exiting from the outlet side of the conveyance conduit.
2. Process according to Claim 1, thereby characterized, that subsequent to the first forward stroke the branch pipe is switched over to the respective other conveyor cylinder and thick matter is pressed into the conveyance conduit by the forward stroke of this piston, without it exiting the outlet side of the conveyance conduit.
3. Process according to Claim 1 or 2, thereby characterized, that subsequent to a forward stroke thick matter is sucked out of the conveyance conduit in a backward stroke without switching of the branch pipe.
4. Process according to one of Claim 1 tthrough 3, thereby characterized, that subsequent to a backwards stroke thick matter is pressed with forward stroke into the conveyance conduit (20) without switching over of the branch pipe, without it exiting the outlet side of the conveyance conduit.
5. Process according to one of Claims 1 through 4, thereby characterized, that the movement stroke is repeated cyclically during the pausing of the pumping in the manner of a sequential control.
6. Process according to one of Claims 1 through 5, thereby characterized, that during the pause in pumping the thick matter in the material reservoir (14) is kept in movement by the back and forth switching of the branch pipe (18) and/or at least one mixer (34).
7. Process according to Claim 6, thereby characterized, that the direction of rotation of the stirrer located in the material reservoir (14) is reversed periodically or stochastically, preferably in relationship to the piston stroke.
8. Process according to one of Claims 1 through 7, thereby characterized, that during the pausing of the pump supplemental stirrers engaging in the material reservoir are brought into operation preferably with alternating direction of rotation.
9. Process according to one of Claims 1 through 8, thereby characterized, that the forward and backward stroke carried out during the pausing of pumping extends over least a part of the length of the cylinder.
10. Process for controlling a thick matter pump, including two conveyor cylinders (10) communicating via openings (12) with a material reservoir (14) and with conveyor pistons (26) operated in counterstroke, as well as a pipe branch (18) provided within the material reservoir (14) connected on the inlet side alternative with one of the openings (12) of the conveyor cylinders with freeing of the respective other opening and on the outlet side connected with a conveyance conduit (20), in which thick matter, preferably liquid concrete, is suctioned in during pump operation through the conveyor cylinder (10) which is open at the time towards the material reservoir (14) and is conveyed through the other conveyor cylinder (10) which is connected to the branch pipe (18) and through the conveyance conduit (20) with building up of a thick matter column towards the outlet thereof, wherein during a pausing of pumping the thick matter column in the conveyance conduit (20) and/or the branch pipe (18) and/or the conveyor cylinders (10) is at least temporarily maintained in motion by operating the conveyor piston (26) and/or the branch pipe (18) for producing an alternating back and forth movement of the thick matter column, without thick matter exiting from the outlet side of the conduit (20), thereby characterized, that during the pause in pumping the branch pipe (18) is pivoted to an intermediate position with partial bridging between the two cylinder openings (12), and that the piston (26) is controlled in counterstroke with bringing about a movement in the thick matter, preferably slower than in the case of a pumping operation.
11. Process for controlling a thick matter pump, including two conveyor cylinders (10) communicating via openings (12) with a material reservoir (14) and with conveyor pistons (26) operated in counterstroke, as well as a pipe branch (18) provided within the material reservoir (14) connected on the inlet side alternative with one of the openings (12) of the conveyor cylinders with freeing of the respective other opening and on the outlet side connected with a conveyance conduit (20), in which thick matter, preferably liquid concrete, is suctioned in during pump operation through the conveyor cylinder (10) which is open at the time towards the material reservoir (14) and is conveyed through the other conveyor cylinder (10) which is connected to the branch pipe (18) and through the conveyance conduit (20) with building up of a thick matter column towards the outlet thereof, wherein during a pausing of pumping the thick matter column in the conveyance conduit (20) and/or the branch pipe (18) and/or the conveyor cylinders (10) is at least temporarily maintained in motion by operating the conveyor piston (26) and/or the branch pipe (18) for producing an alternating back and forth movement of the thick matter column, without thick matter exiting from the outlet side of the conduit (20), thereby characterized, that during the pausing of pumping a mechanical stirring element is introduced into the conveyor line that causes movement within the thick matter column present therein.
12. Process according to claim 11 thereby characterized, that the stirring element is provided on an articulated shaft or string elastic shaft associated with a rotation and/or push drive.
13. Process according to one of Claims 1 through 12, thereby characterized, that the outlet end of the conveyance conduit, during pausing of pumping, is lifted to the extent that no thick matter flows out of the outlet side under the influence of gravity.

Images