EP2387667A1

EP2387667A1 - Method for feeding pasty masses and pump device for feeding pasty masses

Info

Publication number: EP2387667A1
Application number: EP10704309A
Authority: EP
Inventors: Friedrich Schwing; Stefan Schwing
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-01-16
Filing date: 2010-01-14
Publication date: 2011-11-23
Anticipated expiration: 2030-01-14
Also published as: CA2749386A1; ES2414866T3; WO2010081695A1; RU2011134273A; RU2477813C1; JP2012515294A; DE102009005318B3; MX2011007516A; US9046086B2; KR20110123243A; CN102282370A; US20160040659A1; EP2387667B1; ZA201104288B; US20110274572A1; PL2387667T3

Abstract

The invention relates to a method for feeding pasty masses using a pump device which has a piston pump with at least two cylinders with in each case one piston, in which pump device each cylinder is connected via an inlet opening, which can be closed by an inlet slide assigned thereto, to a pre-fill container, and in which pump device each cylinder is connected via an outlet opening, which can be closed by an outlet slide assigned thereto, to a feed line, - in which method pasty mass is fed from the pre-fill container into the respective cylinder during a suction stroke of a cylinder with the inlet opening open and the outlet opening closed and pasty mass is fed into the feed line during a pumping stroke of a cylinder with the outlet opening open and the inlet opening closed, in which method the piston speed is greater during the suction stroke than during the pumping stroke, in which method at the end, toward the end or shortly after the end of the suction stroke, the inlet opening is closed by the inlet slide and thereafter a compression of the pasty mass takes place in the cylinder before the outlet opening is opened.

Description

"Process for conveying mushy pulps and pumping device for conveying mushy pulps"

The invention relates to a method for conveying mushy masses with a pumping device having a piston pump with at least two cylinders each having a piston, wherein each cylinder via an associated inlet opening with a Vorfüllbehälter and each cylinder via an associated outlet opening with a Support line is connected. Furthermore, the invention relates to a pumping device for pumping slurry with a piston pump with a cylinder having a piston and which is connected via an inlet opening which can be closed by an inlet slide, with a Vorfüllbehälter.

In the promotion of concrete pumping devices are used, which are regularly formed from piston pumps having two cylinders, each having a piston. The cylinders refer to the mushy mass to be conveyed in a so-called suction stroke from a Vorfüllbehälter and then promote the absorbed mushy mass in a so-called pumping stroke in a subsequent to the piston pump delivery line. In this case, the pistons of the two cylinders are operated in opposite directions, in order to promote evenly pulpy mass in the delivery line. The delivery line of such a pumping device can take a considerable length. Often it is part of a crane jib and serves to promote pulpy mass from the location of the pumping device to remote ends of the site. The length of the delivery line brings with it that even the smallest interruptions in the flow of the mushy mass due to the inertia to significant pivoting movements lead the support line. Efforts are therefore being made to develop methods which permit continuous delivery of pulpy mass.

Practical methods of conveying pulpy mass are known, which are said to be continuous. However, if one analyzes the conveying path of pulpy mass from the inner cylinder space, from which it is pressed by the piston, to the outlet end of the delivery line, then it can be seen that even with these methods known from practice, although an improved uniformity of the promotion is possible However, continuous promotion does not take place. Also in these pumping devices, in the conveying path of mushy mass components, in particular valves, arranged, the valve body are arranged in a closed position in a mushy mass displacing position, while the valve body in an open position from the provided for the promotion of pulpy mass delivery chamber taken out becomes. This creates a gap in the flow at each opening. This gap is filled, in which pulpy mass, which is already downstream of this gap, sags back. This is to the detriment of the uniform promotion of mushy mass in the conveying direction, so that can not be spoken of a real continuous promotion of pulpy mass.

With a 2-cylinder piston pump for the continuous delivery of concrete according to DE 42 08 754 A1 a real continuous promotion is achieved. However, it showed an unacceptably high wear on the opening of the pivot tube (there: 104) and on the laterally mounted slide plates (there: 101, 102) on the one hand and on the other hand on the so-called spectacle plate on which the opening of the pivot tube with the slide plates sealingly sliding along. It became clear that switching under load with this arrangement caused the following unsolved problems:

1) The abrasive, fine-grained constituents of the concrete were pressed into the sealing gaps during the switching process by the continuously maintained delivery pressure. They caused a high switching resistance of the slide, which still led to the usual discontinuous pumps high wear due to the very long switching paths of the slide.

2) From point 1) results in a very high drive work, i. a required very high switching capacity during a longer period.

With the patent application, which became EP 1 003 909 B1, a continuously conveying 2-cylinder concrete pump with a total of 2 slides is proposed, in which one slide switches at "constant pressure" and the other at "zero pressure". In the switching with constant pressure slide the same pressure is generated before the switching operation by compression of the extracted concrete within the pivot tube, as he constantly outside the pivot tube in the pressure housing and the next leading Promotion line prevails. Therefore, there is no pressure difference between the inside and outside of the on the inside of the pressure housing along sliding opening of the swivel tube. Therefore, fine, abrasive components of the concrete are not pressed by a hydrostatic pressure difference in the sliding column. Rather, there is a state that is very similar to an unpressurized state.

The shut-off valve in the suction line from Vorfüllbehälter to the pivot tube opens only after relaxation of the concrete through the suction stroke and closes before the compression process for the sucked concrete. The switching operations of this suction slide therefore take place without hydrostatic pressure in the concrete ("zero pressure"). These impressive advantages of the type described here of EP 1 003 909 B1 are offset by the following disadvantages:

The pressure housing is very large, at a today's usual maximum concrete pressure of about 90 bar very difficult and only to clean with considerable installation effort. Particularly disadvantageous are the tight bends, the concrete must pass through the concrete standing in the pressure housing on the way in the delivery line during the pumping stroke on the suction swivel tube. Therefore, this pump can not promote very coarse concrete mixtures. Another disadvantage is that when switching to the other cylinder, the mouth of the pivot tube must find space between the two cylinder openings. This results in such a large center distance for the two delivery cylinders that the two cylinders can not, as required for a sufficiently low filling height of the prefilling container, be guided in an inclined manner between the spars of the carrier vehicle.

DE 10 2005 008 938 B4 also has a total of 2 slides, which each act for both delivery cylinders. A gate valve is a 4-way gate valve with 2 switching positions that switches here at "zero pressure", eg the swivel pipe in the open pre-fill tank, which is common in discontinuous pumps, plus a gate valve in the delivery line, which always switches at constant pressure DE 10 2005 008 938 B4 compared to EP 1 003 969 B1, inter alia, that not only constant pressure or zero pressure prevails during the switching process, but that at least when switching with constant pressure gate valve, an automatic ring can be used, the hydrostatic contact pressure by the concrete pressure at constant pressure The reason for this is that after the compression process, the same pressure exists on the outside and inside of the cutting ring, and therefore, the contact surface of the cutting ring with its sliding partner, the swivel body, is subjected to the pressure of the gap, which is one of the cutting rings hydrostatic contact force against acting force of equal size exercises. For the contact pressure during the switching process remains only in comparison much lower and arbitrary biasing force of acting as a spring sealing ring of the automatic ring left. The automatic ring therefore acts exclusively for the duration of the switching operation or during the equal pressure - A -

Scraper. In this way, the friction and thus the wear and the required drive power for the slide is reduced to a minimum.

The disadvantages of the type according to DE 10 2005 008 938 B4 are as follows: The two additional components required for the normal swivel tube are the gate valve, which has to be stored downstream about 1 m downstream of the swivel tube in the delivery line and which, for reasons of space, still further downstream Delivery line to be integrated equalizing cylinder.

The compensating cylinder patented therein corresponds in terms of conveying action to two cylinders connected in parallel, whereby the piston stroke is halved compared with previously known compensating cylinders (see DE 42 081 54 A1, FIG. In addition, although the driving hydraulic cylinder is not installed "in line" behind the delivery cylinder, but between the two, this compensation cylinder requires so much space that it is difficult to place on a truck-mounted concrete pump and sufficiently secure. In addition, this compensating cylinder is an expensive, complicated and very heavy assembly.

Against this background, the invention has for its object to propose a method for the continuous promotion mushy masses, which is adapted to allow even more uniform promotion of pulpy mass. At the same time a pumping device for conveying mushy masses to be proposed, which allows a particularly good sealing of the inlet opening.

The method is based on the basic idea to provide for each cylinder of the piston pump own inlet opening with its own inlet slide and its own outlet opening with its own outlet slide. This makes it possible to carry out the filling of the respective cylinder and the discharge of pulp in the delivery line through the respective cylinder independently of the operations of the other cylinder / cylinders. Thus, during the pumping stroke of the one cylinder, ie the continuous pumping slurry from one cylinder into the delivery line, another cylinder can be filled with pulpy mass and, on the other hand, precompression of pulpy mass can already be carried out in this newly filled cylinder , This makes it possible, in particular, to move a valve body of the outlet slide of this newly filled cylinder from a closed position to an open position only when the pressure of the cylinder in the cylinder pressurized by the slurry mass is substantially the pressure of the mushy mass on the capacity corresponds to the outlet slide. As a result, the switching of the outlet slide under equal pressure and the switching of the inlet slide at zero pressure can take place in a particularly simple manner.

For this purpose, the method according to the invention provides that - During a suction stroke of a cylinder with the inlet opening and the closed outlet opening pulpy mass from the Vorfüllbehälter is conveyed into the respective cylinder and in a pumping stroke of a cylinder with open outlet and closed inlet opening mushy mass is conveyed into the delivery line,

the piston speed is greater during the suction stroke than during the pump stroke,

- At the end, towards the end or shortly after the end of the suction stroke, the inlet opening is closed with the inlet slide and then compression of the mushy mass in the cylinder takes place before the outlet opening is opened.

This method makes it possible to switch the individual inlet and outlet valves under special favorable conditions.

The inventive method makes it possible to close the respective inlet slide at a time at which the mushy mass drawn into the cylinder during the suction stroke has the same pressure as the mushy mass in the prefilling container. In the area of the prefilling container and the cylinder which has just been filled, this leads to a substantially pressure-free situation of the concrete, which is called "zero pressure" for reasons of simplification. Furthermore, the method according to the invention makes it possible to reopen the respective inlet slide only when the associated cylinder has started its suction stroke. By not opening the inlet slide of the respective cylinder until it has started its suction stroke, in a preferred embodiment of the method according to the invention, it is possible that the pressure in the cylinder after the pumping stroke has ended and the outlet slide is closed degrades pulpy mass and drops to the pressure level of pulpy mass in Vorfüllbehälter. This makes it possible to open the inlet gate in a situation where there is no pressure difference between the priming tank and the cylinder contents. This also makes it easy to construct the inlet slides. It is not possible to use pressure balanced and very short flat slide valves. These can be particularly well sealed by an automatic ring, as provided as part of the pumping device according to the invention.

The inventive method also makes it possible to close the outlet slide in a state in which the mushy mass in the cylinder and the mushy mass in the delivery line has the same pressure. This state, in which the mushy mass in front of a slider and the pulpy mass after a slider has the same pressure, so the slide is thus in an environment of equal pressure, is called "equal pressure" for reasons of simplicity.

The method according to the invention provides that prior to opening the outlet slide, compression of the pulpy mass drawn into a cylinder during the suction stroke takes place at the current delivery pressure, in which senen inlet slide and is compressed against the closed outlet slide of this cylinder. As a result, a situation of equal pressure is created before opening the outlet spool. This situation of equal pressure also makes the use of an automatic ring provided on the valve body of the outlet slide or on the outlet opening of the outlet slide closed by the valve body particularly expedient in a preferred embodiment. The equal pressure situation creates a situation very similar to zero pressure. In an automatic ring provided at the outlet opening closed by the valve body of the outlet slide, the contact surface between the automatic ring and the swivel body is also pressurized by the compression of the sucked-in concrete from the outside with pulpy mass (in particular cement paste, ie the fluid constituents of the concrete). As a result, the hydrostatic contact pressure of the automatic ring is canceled by the equal, opposite acting force of the nip pressure. This ensures that the automatic ring, similar to the situation at zero pressure, is pressed during the switching process with constant pressure only with the freely selectable, low bias by a resilient sealing ring. The automatic ring acts only as a scraper, whereby the swivel resistance and wear are a minimum.

The method according to the invention allows the hydrostatic contact pressure of the automatic ring, which is required to prevent lifting at differential pressure, to be produced only at standstill after the switching operation and when pressure differences occur at the closed slide, both at the inlet slide and at the outlet slide.

The method according to the invention makes it possible to use a pumping device which, compared to discontinuous pumps, can only be constructed with a slight additional expenditure through the two inlet slides, which would not be technically necessary for a discontinuous pump with two rotary valves. For example, the two inlet slides provided in the prefilling container can be designed to be pivotable along the housing wall of the prefilling container. The pump device which can be used for the method according to the invention can be made compact, inexpensive and of a lightweight design. The overall length and the filling height at Vorfüllbehälter can be kept the same size compared to the conventional, discontinuous pumps with swivel tube. The wear on the slides can be kept extremely low by the prevailing during the switching zero pressure, or zero pressure similar ("equal pressure") situation despite the simultaneous Aufrecherhaltung the discharge pressure. Likewise, the switching resistance of the slide and the required switching power and the required switching time can be kept low. The sliders which can be used in the method according to the invention can also have very low masses. This is because of the numerous switching operations, which must be done because of the very tight schedule in a very short time, particularly advantageous. Furthermore, it is of advantage that in the method according to the invention a pumping device can be used in which the swivel tube known from EP 1 003 969 B1 can be dispensed with. This is particularly advantageous if pulpy mass is to be promoted with a high proportion of broken grain, which tends to so-called bridge formation in Vorfüllbehälter. In the case of this type of mushy mass, the so-called pipe-turn-type pumps (pumps with a swivel tube, as shown, for example, in EP 1 003 969 B1) represent a step backwards compared to pumps with flat slides. The method according to the invention makes it possible to use flat slides. If it is possible to dispense with the swivel tube, which requires a great deal of space in the pre-filling container for its movement, then an effective stirrer can be installed which is also effective in the critical region of the inlet openings. According to the inventor, the swivel tubes in the prefilling container generate cavities by their movement and prevent their effective destruction.

In a preferred embodiment of the method, an outlet slide is used, which is designed as a rotary valve. As a rotary valve such slides are understood that can be rotated within a predetermined by the slide housing from a closed position to an open position without the valve body of the slider leaves the space defined by the slide housing. Alternatives to rotary valves are linear flat slide and so-called plunger with cylindrical shut-off elements, in which a valve body from a laterally arranged next to the space defined by the slide housing opening position is inserted linearly in the space defined by the slide housing to take its closed position. Rotary valves can be used particularly well to be moved neutral in volume from a closed position to an open position, ie without moving the valve body from the closed position to the open position, or back to the closed position, a gap, or an excess amount in the Valve body arises both upstream and downstream surrounding mushy mass.

Particularly preferred in the method according to the invention, an outlet slide is used, which is a rotary valve with a valve body in a slide housing, in which the slide housing is part of the pumping chamber, in which the mushy mass is conveyed by the respective cylinder in the delivery line and the valve body in all Positions of the outlet slide in the valve body remains.

This design makes it possible to convert the valve body volume-neutral from the closed position to the open position and back. As a result, the continuous promotion of mushy mass is supported, since in the pumping chamber no gap arises when the shut-off moves out of the pressure chamber when opening. Conversely, when entering the pressure chamber, it would greatly increase the effective delivery rate and likewise not achieve continuity. In a preferred embodiment of the method according to the invention, the valve body of the outlet spool is moved from a closed position to an open position when the pressure of the mushy mass pressurized in the cylinder by compression corresponds substantially to the pressure of the mushy mass on the delivery line side of the outlet spool , As a result, a constant pressure situation is achieved, which allows a particularly easy switching of the outlet slide with little wear.

In a preferred embodiment of the method according to the invention, an inlet slide is used, which is designed as a pivot valve. In the case of a pivoting flat slide, the flat valve body of the slide is pivoted by a pivoting movement from an opening position located laterally next to the opening to be closed into a closing position closing the opening to be closed. Such pivoting flat slide can be made particularly simple. The method according to the invention makes it possible to open the inlet slide in a zero-pressure situation and thus makes it possible to use a swiveling slide valve which is simple to construct and which can be switched because of or after the pressure relief. Especially with high delivery resistances in the delivery line, the pivoting resistance would be virtually insurmountable and the wear extremely high.

The method according to the invention can be operated in particular as follows:

1. With the inlet port open and the outlet port closed, the piston of a cylinder is pulled back to make a suction stroke. This pulpy mass is sucked from the Vorfüllbehälter in the cylinder.

2. At the end, toward the end or shortly after the end of the suction stroke, the inlet port is closed by pivoting the inlet gate to its closed position. The choice as to whether the closing of the inlet opening at the end, towards the end or shortly after the end of the suction stroke, is mainly due to the system. For example, due to the switching times of the inlet gate, it may be necessary to begin the pivotal movement of the inlet gate into the closed position before the piston has reached its fully retracted position in the cylinder. On the other hand, the inertia of a possibly provided switching hydraulics can lead to the inlet slide being closed only after end position sensors have recognized that the piston has reached its end position in the cylinder.

3. The piston of the cylinder is moved towards the outlet opening and the inlet opening, thereby compressing the mushy mass in the cylinder. 4. The outlet opening is opened by pivoting the outlet slide. Now the associated delivery cylinder is ready for pumping.

5. After a short reserve time interval (for the actual pumping of pulpy mass), the pumping piston reaches near its end position. Now, the hydraulic control valve is preferably switched so that the oil flow in the hydraulic system controlling the valves can be temporarily split between the two cylinders. The effective flow rate in the concrete remains constant. After reaching the end position promotes only the following cylinder. In this way, complete continuity can be achieved.

6. At the end, or towards the end of the pumping stroke, the outlet opening is closed by pivoting the outlet slide into the closed position.

This switching process takes place under constant pressure, which low switching resistance and low wear can be achieved.

7. The piston is retracted in the cylinder, so that even in the cylinder and in the control housing located mushy mass is relaxed. The inlet gate is pivoted to its open position when the pressure of the mushy mass in the cylinder corresponds to the pressure of the pre-fill tank.

The other cylinder is operated in opposite directions, wherein the steps 1 to 4 of the movement sequence of the one cylinder are carried out completely in the time in which the piston of the other pulp mass promotes pulp with the current delivery pressure in the delivery line. For this purpose, the piston speed during the suction stroke is to be selected to be greater than during the pumping stroke in order to keep the time to be provided for carrying out steps 1 to 4 low. This coordination of the individual steps to one another means that the pulpy mass is continuously pumped into the delivery line. As soon as the pumping stroke of one cylinder is completed, the other cylinder with precompressed mushy mass is ready to continue the promotion.

An alternative embodiment of the method according to the invention for conveying mushy masses provides for the use of a pumping device having a piston pump with at least two cylinders, each having a piston, in which each cylinder via a closable with its associated inlet slide inlet opening with a Vorfüllbehälter and in which each cylinder is connected to a delivery line via an outlet opening which can be closed by means of an outlet valve assigned to it. In this method, a cleaning body is introduced into at least one of the cylinders, which is introduced by means of compressed air through the open outlet slide in the delivery line and promotes the present in the delivery line pulpy mass through the delivery line. This alternative training is advantageous legally feasible in combination with the previously described embodiment of the method according to the invention.

The alternative training offers the opportunity to clean the pumping device very well. In addition to the problem of discontinuity, there is the further problem of disposal of the residual concrete. If a piston pump sucks pleasure instead of concrete, a promotion is no longer possible. The then still in the filled delivery line on the distribution boom concrete and located in Vorfüllbehälter no longer suckable concrete are called "residual concrete". The concrete from the delivery line is sucked back in practice by sucking back a "wiper ball" with the help of gravity in the Vorfüllbehälter. For longer masts, the pre-fill tank overflows, resulting in a large cleaning action.

In the design of the pumping device according to the invention with two preferably with automatic rings well sealed and independently switchable inlet sliders can suck in each case through the two suction openings each ball and promote the two legs of a possibly provided trouser tube and the entire concrete with compressed air promote to the place of introduction. The compressed air pushes the cleaning body, preferably the ball, in front of him through the delivery line.

The pumping device for pumping masses according to the invention comprises a piston pump with a cylinder which has a piston and which is connected to a prefill container via an inlet opening delimited by an eyeglass plate which can be closed by an inlet slide, the inlet slide facing the cylinder interior Has closure surface, wherein

the inlet slide has a pivotable basic body,

the closure surface is formed, at least in part, by the surface of a piston which is movable relative to the base body and which can dip into a closed cavity formed in the base body when a medium pressure acts on the piston from the inside of the control housing,

- In the cavity, a fluid is provided which can be compressed by the immersion of the piston,

- Is designed as an annular piston cutting ring is provided which has a surface which faces the cavity, and which is pressed in the closed position of the inlet slider by the pressure of the fluid against the spectacle plate.

This construction of an inlet slide makes it possible to provide a pivoting flat slide with a cutting ring (automatic ring), although the cutting ring is not flowed through by the medium flow as in EP 0 057 288 A1. A particular advantage of this pivot-flat slide is its very flat design, which allows an optimal effect of the agitator and the suction ports. During the switching process, which generally takes place in the approaching pressure-free state ("zero pressure"), the cutting ring is pressed only as a scraper with the freely selectable biasing force of a biasing spring against its associated sealing surface.Thus, the wear on such a cutting ring can be reduced because of Wear occurs almost exclusively during the switching process and depends on the surface pressure with about the 3rd power.

The peculiarity of such an arrangement on an inlet slide is that on one side of the inlet slide in Vorfüllbehälter regular ambient pressure prevails. The proposed construction now offers the possibility, with the cavity adjacent to both the movable element and the cutting ring, of "deflecting" the force generated by the pressure of the pulpy mass to the side of the cutting ring facing away from the pulpy mass. In the closed position of the inlet slider, the mushy mass presses on pressure on the outwardly facing surface of the movable part. This pressure is transmitted via the inwardly directed surface to the fluid in the cavity. This - preferably incompressible - fluid exerts the pressure on the inwardly facing surface of the cutting ring and thus presses it onto the sealing surface surrounding the inlet opening. Penetrating now when acted upon by the medium pressure pulpy mass between the cutting ring and its associated sealing surface, the cutting ring with the nip pressure of mushy mass, which is on average about 50% of the medium pressure, applied in the direction of the sealing surface away. Since the cutting ring but is pressed simultaneously over the fluid in the cavity with the pressure of pulpy mass against this sealing surface, the contact force outweighs in the direction against the spectacle plate. It is successfully prevented that the cutting ring is lifted from the sealing surface. The contact pressure is also increased by the additional existing bias, by the spring element. During the switching process, which takes place at the inlet slide at "zero pressure", the preload ensures the function of the cutting ring as a scraper.

The spectacle plate is either integrally formed on the Vorfüllbehälter or as a separate component. The term "spectacle plate" does not define any particular geometry, but merely designates the surfaces against which the automatic ring (cutting ring) is pressed in a sealing manner.

In a preferred embodiment, the inlet slide on a biased spring element which acts in the same direction as the medium pressure on the piston. As a result, a bias is effected.

In a preferred embodiment, the spring element is designed as a plate spring or is formed by a plurality of disc springs. Disc springs are particularly well suited for installation in the present invention designed inlet slider. In a preferred embodiment, the piston on its side facing the fluid on a substantially cylindrical stem which is slidably mounted in a cylindrical bore of the housing and together with the jacket of the piston forms a guide which secures the piston against tilting.

In a preferred embodiment, the stem of the piston penetrates the body axially movable and sealed. As a result, the current state of the piston can be seen from the Vorfüllbehälter from. This gives an indication of the wear on the cutting ring and the spectacle plate, or on the correct amount of the introduced fluid.

In a preferred embodiment, the spring element is supported on the cutting ring.

In a preferred embodiment, the cutting ring is designed as an annular piston with a U-shaped ring cross-section, which is sealed with its outer inner diameter relative to the base body and with its inner inner diameter relative to the piston sliding.

In a preferred embodiment, the hydrostatic force acting on the closed flat slide when subjected to pressure by the medium in the slide housing is partially absorbed by the tensile force of a pivot shaft supporting the inlet slide and partly by a force with which the body partially guided in a guide groove supported on the guide groove.

In a preferred embodiment, the inlet slider is connected to a pivot shaft and the connection of the base body with the pivot shaft allows a slight oscillating movement about a substantially horizontal, perpendicular to the pivot axis extending axis.

In a preferred embodiment, the spring element is tensioned by introducing the fluid into the cavity, wherein the piston moves against the effective direction of the medium pressure and the fluid space is secured by a check valve or a plug against leakage of the fluid.

In a preferred embodiment, the inlet slide is a swiveling slide.

In a preferred embodiment, the inlet slider has a spring element which presses a component of the inlet slider into the cavity in such a way that the fluid located in the cavity is precompressed. As a result, a pressure situation is created, which keeps components of the inlet slide in a first operating situation. In addition, can be adjusted by this bias the pressure at which the cutting ring is pressed against the sealing surface.

In a preferred embodiment, a fat or an oil is used as the fluid. It has been found that a grease, or an oil is particularly suitable to be used in the operating environment of conveying mushy masses for the application of pressure to the cutting ring.

In a preferred embodiment, the spring element is designed as a plate spring. It has been found that the use of a plate spring allows a particularly flat design of the inlet slide in the pump device according to the invention.

In a particularly preferred embodiment, the movable element which can exert a pressure exerted by the pulpy mass on the fluid in the body is forced into the cavity by the spring element, so that the fluid in the cavity is pre-compressed. This makes it possible to realize the inlet slider with a small number of components.

In a particularly preferred embodiment it is provided that

- The cavity is formed by a recess in the base body, which opens in the base body in the direction of the cylinder-facing side of the inlet slider and has a round opening with an opening diameter which is greater than the diameter of the inlet opening,

- The opening of the recess is closed by a cover and arranged between the outer periphery of the lid and the wall defining the opening opening cutting ring to form the cavity.

This design makes it easy to assemble the inlet slider of the pump device according to the invention.

In a preferred embodiment, the lid is movably formed relative to the base body and forms the movable element. This design makes it easy to run the inlet slide with a small number of components.

In a particularly preferred embodiment, the lid has a stop which abuts against a stop of the cutting ring when the lid is pressed by the fluid in the cavity to the outside. By the interaction of the two stops, the lid is securely held in the inlet slide. The cutting ring is held by its abutment on the wall defining the opening, so that the lid can be supported by means of a stop on the cutting ring.

In an alternative design, the lid is fastened to the base body and has an opening in which the movable element, for example a piston, is movable is arranged relative to the lid. This may increase the number of components of the inlet slide compared to the aforementioned design. However, this design leads to a more stable inlet slide.

In a preferred embodiment of the pump device according to the invention, this has at least two, in particular exactly two cylinders, each having a piston. Each cylinder of this preferred embodiment is connected to a prefill container via an inlet port closable with an inlet gate associated therewith. Each cylinder of this preferred embodiment is further connected to a delivery line via an outlet opening which can be closed by means of an outlet valve assigned to it. This embodiment offers, inter alia, the advantage of easy cleaning of the delivery line. In practice, the so-called purging of the delivery line to avoid the residual concrete, so when cleaning the delivery line, so-called chamber slide are used. These are now superfluous. The preferred embodiment of the pumping device according to the invention may in fact be designed so that the slide can be controlled individually, so that you suck for each cylinder from the Vorfüllbehälter a conventional sponge rubber ball and him in the provided as part of the delivery line downpipe and then extending further delivery line can contribute. These sponge rubber balls can then be blown out of the delivery line with compressed air to the front. This represents a significant simplification of the cleaning of such a pumping device.

In a preferred embodiment, the inventive method is carried out with the pumping device according to the invention. The pumping device according to the invention and the method according to the invention are particularly preferred for conveying concrete and other thick matter such as e.g. Sewage sludge or overburden used in tunnel construction.

The invention will be explained in more detail with reference to a drawing illustrating only one embodiment of the invention. Show:

1 shows a sectional side view of a part of the pumping device according to the invention, in which the inlet slide, the outlet slide, the slide housing, a part of a cylinder, parts of the delivery line and parts of the prefilling container can be seen;

2 is an enlarged detail view of the inlet slider in a sectional side view,

3 is a detail view of an alternative embodiment of an inlet slider in a sectional side view, Fig. 4 is a detail view of another embodiment of the inlet slider in a sectional side view and

Fig. 5 is a detail view of another embodiment of the inlet slider in a sectional side view.

The pumping device shown in Fig. 1 for conveying mushy mass has a piston pump with two cylinders, of which in the illustration of FIG. 1, only one cylinder 1 of the piston pump is shown. The cylinder has a piston 2, which is here in its end position. The cylinder is connected to a prefill container 5 via an inlet opening 3, which can be closed by an inlet slide 4. Furthermore, the cylinder has an outlet opening 6, which can be closed with an outlet slide 7. The cylinder 1 is connected via the outlet opening 6 with a delivery line 8. The delivery line 8 is formed in its region adjacent to the piston pump as a so-called "bifurcated tube", ie as a branch pipe, which brings together the flow rates of the individual cylinders of the piston pump and merges into a (not shown) part of the delivery line, in which the individual partial flows of single cylinder of the piston pump can be promoted together.

The inlet slide 4 of the pumping device is designed as a pivoting flat slide and can be pivoted about the pivot axis A from the illustrated closed position to an open position. The inlet slide 4 has an automatic ring 10 designed as a cutting ring, which surrounds the inlet opening 3 in the closed position of the inlet slide and is pressed at least with parts of an outwardly directed surface against a sealing surface of the body surrounding the inlet opening, in which the inlet opening is formed.

The outlet slide shown in its open position is designed as a rotary valve. The valve body 30 of the outlet slide is arranged in a slide housing 31, wherein the slide housing 31 is the delivery chamber through which the pulpy mass is sucked from the respective cylinder from the Vorfüllbehälter and is conveyed in the pumping stroke in the delivery line. The valve body 30 remains in all positions of the outlet slide in the valve body and can thus be switched to volume neutral.

Surrounding the outlet opening 6 is an automatic ring 32. This automatic ring 32 can be designed in the manner of one of the cutting rings described in more detail in EP 0 057 288 A1 (where it is denoted by the reference numeral 14), wherein in EP 0 057 288 A1 the cutting ring is represented as part of the component to be pivoted (there of the switching element 3) while here the cutting ring is preferably formed as part of a stationary remaining part of the pumping device. Alternatively, the Cutting ring 32 are formed comparable to the arrangement of the cutting ring in EP 0 057 288 A1 as part of the valve body 30 to be pivoted.

In the Vorfüllbehälter a stirrer 60 is provided. This can be formed so that it is effective even in the critical region of the suction due to the low height of the valve body formed as a pivot valve slide of the inlet slide 4.

The embodiment of the inlet slide 4 shown in FIG. 2 shows that the inlet slide 4 can be formed with a flat basic body 11 which can be pivoted about the pivot axis A. The inlet slide 4 has a relative to the main body 11 movable element 13. This movable element 13 is formed in the embodiment shown in Fig. 2 as a piston In the closed position of the inlet slide 4 shown in FIG. 2, the movable member 13 is in an outwardly facing surface 15 then in contact with mushy mass, when the Cylinder-facing side 16 of the inlet slide is in contact with mushy mass, which is located in the valve body 31. Via the movable element 13, a pressure exerted by the mushy mass on the outwardly directed surface 15 of the movable element 13 can be exerted on a fluid located in the entire sealed cavity 12 and 12a. In this case, the piston 13 is secured against tilting by its guidance in the cover 17 and in the base body 11. The subspaces 12 and 12a are interconnected by a channel 44a.

The entire cavity 12 and 12a is formed by recesses in the base body 11, which opens in the base body 11 in the direction of the side facing the cylinder 1 side 16 of the inlet slide 4 and has a round opening with an opening diameter D1 which is larger than that Diameter D2 of the inlet opening 3. The opening of the recess is closed by a cover 17 and the cutting ring 10 arranged between the outer periphery of the lid 17 and the wall 18 delimiting the opening.

The cutting ring 10, which surrounds the inlet opening in the illustrated closed position of the inlet slide 4, is in the embodiment shown in Fig. 2 completely with its outwardly directed surface 19 against a surrounding the inlet opening 3 sealing surface 20 of the body, in which the inlet opening 3 is formed is pressed (the slide housing). With its inwardly directed surface 21 of the cutting ring 10 limits the cavity partially.

In the cavity 12 and 12 a, a low-viscosity fat or a viscous oil is provided. This can be introduced via an inlet opening, not shown, by means of a grease gun in the cavity. Furthermore, the cavity of the inlet slide 4 has a plate spring 22. This pushes the piston formed as a movable part 13 into the cavity, so that the fluid located in the cavity is precompressed. With the Vorkomprimierungsdruck thus generated, the fluid in the cavity exerts pressure on the inwardly facing surface 21 of the cutting ring 10 and presses it with this pressure against the sealing surface 20. By suitable choice of the plate spring 22 thus the contact pressure can be adjusted with the the cutting ring is pressed against the sealing surface 20 during the non-pressurized switching operations (at "zero pressure").

In operation, for example, if, according to the method according to the invention, a compression of pulp in the cylinder takes place before the outlet slide 7 is opened, the mushy mass in the cylinder is pressed against the cylinder 1 facing side 16 of the inlet slide. With the same pressure, the cylinder 1 facing surface 15 of the movable member 13 is pressurized. The movable member 13 urges the fluid in the cavity 12 at the same pressure. Thereby, the cutting ring 10 is pressed against the sealing surface 20 with both the biasing pressure and the pressure transmitted by the movable member 13. At the same time, the cement paste of the pulpy mass presses into the gap between the surface 19 and the sealing surface 20 as a hydrodynamic nip pressure, as described in detail in EP 0 057 288 A1. This nip pressure can not lift the cutting ring 10 from the sealing surface 20, because the average hydrodynamic nip pressure is only about 50% of the applied by the fluid pressure on the cutting ring hydrostatic contact pressure. The cutting ring is also pressed in accordance with the bias of the plate spring sealing on the sealing surface 20.

The embodiment of the inlet slide 4 shown in FIG. 3 shows that the inlet slide 4 can be formed with a flat main body 41 which can be pivoted about the pivot axis (in the partial view of one half of the inlet slide (not shown in detail) in FIG The inlet slider 4 has a member 43 movable relative to the main body 41. This movable member

43 is formed in the embodiment shown in Fig. 3 as a lid. The movable member 43 defines with its external pressure gauge a cavity whose diameter corresponds to the inner diameter of the cutting ring 10. The bore 44 serves to guide the movable element without tipping. The space

44 is connected to the remaining cavity via the channel 44a. In the closed position of the inlet slide 4 shown in FIG. 3, the movable element 43 is in contact with mushy mass with an outwardly directed surface 45 when the cylinder-facing side 46 of the inlet slide 4 is in contact with pulpy mass, which is located in the slide housing 31. Via the movable element 43, a pressure which the mushy mass exerts on the outwardly directed surface 45 of the movable element 43 can be exerted on a fluid located in the cavity 42. The cavity 42 is formed by a recess in the main body 41, which opens in the base body 41 in the direction of the cylinder 1 facing side 46 of the inlet slide 4. The opening of the recess is closed by the movable piston 43 designed as a cover 47 and the cutting ring 40 arranged between the outer circumference of the cover 47 and the wall 48 delimiting the opening to form the cavity 42.

The cutting ring 40 which surrounds the inlet opening in the illustrated closed position of the inlet slide 4 is completely in the embodiment shown in FIG. 3 with its outwardly directed surface 49 against a sealing surface 50 of the body surrounding the inlet opening 3 in which the inlet opening 3 is formed is pressed (the spectacle plate of the slide housing). With its inwardly directed surface 51 of the cutting ring 40 limits the cavity 42 partially.

In the cavity 42, a low-viscosity fat or a viscous oil is provided. This can be introduced into the cavity 42 via the inlet opening by means of a grease gun.

Furthermore, the inlet slide 4 has one or more disc springs 52. This pushes the "movable" piston 43 formed as a cover 47 into the cavity 42, so that the fluid in the cavity is pre-compressed With the precompression pressure thus generated, the fluid in the cavity 42 exerts pressure on the inwardly directed surface 51 of the cavity Cutting ring 40 and presses this during the unpressurized switching operation with this pressure against the sealing surface 20. By suitable choice of the plate spring 52 thus the contact pressure can be adjusted with which the cutting ring is pressed during the switching operation against the sealing surface 50.

The illustrated in Fig. 3, alternative design of an inlet slider 4 provides that the movable member, which exerts a pressure exerted by the mushy mass on it, on a befindliches in the cavity 42 of the body 41 fluid completely formed by the lid 47 becomes. The lid 47 is movably formed relative to the main body 41. The cover 47 has a stop 53 which abuts against a stop 54 of the cutting ring 40 when the cover is pressed by the fluid in the cavity to the outside. In Fig. 3, an operating situation is shown, in which the stop 53 is not applied to the stop 54, but at the opposite end of the travel. For operation, both end stops should be avoided. Therefore, more fluid must be filled in here (FIG. 3).

In the alternative embodiment shown in FIG. 4, components that are the same as in the embodiment shown in FIG. 3 are shown with reference numerals increased by the number 100. The embodiment of Fig. 4 differs from the embodiment shown in Fig. 3 by the shape of the cutting ring 140 and the support of the spring element 152. The spring element is supported in this embodiment on the cutting ring and not - as in the embodiment of FIG. 3 - on a separate, firmly connected to the main body. Further, the cutting ring 140 is formed as an annular piston with a U-shaped annular cross section, which is sealed with its outer inner diameter relative to the base body 141 and with its inner inner diameter relative to the piston 143 slidably.

The piston 143 has on its side facing the fluid on a substantially cylindrical stem which is slidably mounted in a cylindrical bore of the housing and together with the jacket of the piston forms a guide which secures the piston against tilting. This stem of the piston penetrates the body axially movable and sealed.

The design shown in Fig. 4 of the base body 141 and the cutting ring 140 is flattened outwards and thus allows a climbing of stones, if they could block the pivotal movement of the slider.

In the alternative embodiment shown in FIG. 5, components that are the same as in the embodiment shown in FIG. 3 are shown with reference numbers increased by the number 200. The embodiment of FIG. 5 differs from the embodiment shown in FIG. 4 by the shape of the cutting ring 240 and in that the base body 241 engages around the cutting ring 240 on the outside.

Claims

claims

1. A method for conveying mushy masses with a pump device comprising a piston pump with at least two cylinders (1), each having a piston (2), in which each cylinder (1) via an associated with its inlet slide (4, 104, 204) closable inlet opening (3, 103, 203) with a Vorfüllbehälter (5) and in which each cylinder (1) via a with its associated outlet slide (7) closable outlet opening

(6) connected to a delivery line,

- In which at a suction stroke of a cylinder (1) with the inlet opening (3, 103, 203) and closed outlet opening (6) mushy mass from the prefill container (5) in the respective cylinder (1) is conveyed and a pumping stroke of a cylinder (1) with open outlet opening (6) and closed inlet opening (3, 103, 203) mushy mass is conveyed into the delivery line, - in which the piston speed during the suction stroke is greater than during the pumping stroke,

- In which at the end, towards the end or shortly after the end of the suction stroke, the inlet opening (3, 103, 203) with the inlet slide (4, 104, 204) is closed and then a compression of mushy mass in the cylinder (1) before the outlet opening (6) is opened.

2. The method according to claim 1, characterized in that the outlet slide

(7) is a rotary valve.

3. The method according to claim 2, characterized in that the outlet slide (7) is a rotary valve with a valve body (30) in a slide housing (31), wherein the slide housing (31) is part of the delivery chamber, in which the pulpy mass of the respective cylinder (1) in the delivery line (8) is conveyed and the valve body (30) in all positions of the outlet slide (7) in the slide housing (31) remains.

4. The method according to any one of claims 1 to 3, characterized in that the valve body (30) of the outlet slide (7) is moved from a closed position to an open position when the pressure in the cylinder (1) by the compression with pressure acted mushy mass substantially corresponding to the pressure of pulpy mass on the delivery line side of the outlet slide (7).

5. The method according to any one of claims 1 to 4, characterized in that the inlet slide (4, 104, 204) is a pivot slide.

6. Method for conveying mushy masses with a pumping device comprising a piston pump with at least two cylinders (1) each having a piston (2) , in which each cylinder (1) has an inlet opening (3, 103, 203) which can be closed by means of an inlet slide (4, 104, 204) assigned to it, with a prefilling container (5) and in which each cylinder (1) has an opening with an associated outlet slide (7) closable outlet opening (6) is connected to a delivery line, in particular according to one of claims 1 to 5, characterized in that at least in one of the cylinders a cleaning body is introduced, which by means of compressed air or pressurized water through the open Outlet slider is introduced into the delivery line and promotes the present in the delivery line pulpy mass through the delivery line.

7. A pumping device for pumping slurry with a piston pump with a cylinder (1), which has a piston (2) and a limited by a spectacle plate inlet opening (3, 103, 203) by an inlet slide (4, 104, 204) is connected to a Vorfüllbehälter (5), wherein the inlet slide (4, 104, 204) has a the inside of the slide housing (31) facing the closure surface, wherein the inlet slide (4, 104, 204)

- Has a pivotable base body (11, 41, 141, 241),

- The closure surface is at least partially formed by the surface of a piston movable relative to the main body, which in a in the base body (11, 41, 141, 241) formed, closed cavity (42, 142, 242) can dip when from the Inside the slide housing 31, a medium pressure acts on the piston,

- Is designed as an annular piston cutting ring (10, 40, 140, 240) is provided which has a surface which faces the cavity (12 and 12 a, 42, 142, 242), and in the closed position of the inlet slide (4, 104 , 204) is pressed against the spectacle plate by the pressure of the fluid.

8. A pumping device according to claim 7, characterized in that the inlet slide (4, 104, 204) comprises a biased spring element (22, 52, 152, 252) which acts in the same direction as the medium pressure on the piston.

9. A pump device according to claim 8, characterized in that the spring element as a plate spring (52, 152, 252) is formed or formed by a plurality of disc springs.

10. Pumping device according to one of claims 7 to 9, characterized in that the piston (43, 143, 243) on its side facing the fluid has a substantially cylindrical stem which is slidably mounted in a cylindrical bore of the body and together with the mantle of the piston (43, 143, 243) forms a guide which secures the piston (43, 143, 243) against tilting.

11. A pump device according to claim 10, characterized in that the stem of the piston (143, 243) penetrates the base body (141, 241) in an axially movable and sealed manner.

12. Pump device according to one of claims 7 to 11, characterized in that the spring element (152, 252) on the cutting ring (140, 240) is supported.

13. A pump device according to claim 7, characterized in that the cutting ring (140) is designed as an annular piston with a U-shaped ring cross-section, which with its outer inner diameter relative to the main body (141) and with its inner inner diameter relative to the piston ( 143) is slidably sealed.

14. A pumping device according to any one of claims 7 to 13, characterized in that the hydrostatic force acting on the closed flat slide during pressure loading by the medium in the cylinder is partially absorbed by the tensile force of a pivot shaft carrying the inlet slide and in part by a force, with which the guided in part in a guide groove body is supported on the guide groove.

15. A pump device according to any one of claims 7 to 14, characterized in that the inlet slide is connected to a pivot shaft and the connection of the main body with the pivot shaft allows a slight pendulum movement about a substantially horizontal axis extending perpendicular to the pivot axis.

16. A pump device according to one of claims 7 to 15, characterized in that the spring element is tensioned by introducing the fluid into the cavity, wherein the piston moves against the effective direction of the medium pressure and the fluid space through a check valve or a plug against leakage of the Fluids is secured.

17. Pumping device according to one of claims 7 to 16, characterized in that the inlet slide (4, 104, 204) is a swiveling vane.

18. The method according to any one of claims 1 to 6, characterized in that the method is carried out with a pumping device according to one of claims 7 to 17.