EP3837438B1 - Swivel tube for two-cylinder pumps for viscuous liquids - Google Patents

Description

The invention relates to a swivel pipe arrangement for two-cylinder thick-material pumps, an arrangement comprising a diverter valve and a two-cylinder thick-material pump, each with a corresponding swivel pipe arrangement.

Two-cylinder sludge pumps are particularly in the field of concrete delivery from the prior art, such as EP 0 410 972 B1 , EP 0 052 192 A1 or EP 0 057 288 A1 known. Corresponding pumps have two alternately operated delivery cylinders, the end openings of which open into a material feed container and can optionally be connected to a delivery line via a diverter valve. During the respective suction stroke, the cylinders are open to the material feed container, so that the material to be conveyed gets into the cylinder. For the respective pressure stroke, the cylinders are connected to the delivery line so that the material contained in the cylinders is pressed into the delivery line. For this purpose, the diverter valve comprises an S-shaped pivoting tube, the outlet opening of which, which is directed towards the conveying line, is arranged coaxially to a pivoting axis of the pivoting tube. The inlet opening of the pivot tube is arranged eccentrically to this pivot axis and can be pivoted back and forth between the end openings of the two delivery cylinders.

Cutting rings designed as wear rings are known for sealing contact with the front opening of a feed cylinder during the pressure stroke so that the material to be conveyed does not escape between the feed cylinder and pivot tube, which can be axially displaced within certain limits relative to the pivot tube. Between the cutting ring and the actual swivel tube is an automatic ring made of flexible Arranged material, with the radially acting on the automatic ring swivel tube internal pressure is converted into an axial force acting on the cutting ring, so that with the resulting contact pressure a sealing system between the cutting ring and delivery cylinder can be ensured.

In the case of corresponding systems, the contact pressure is directly, generally linearly, dependent on the internal pressure in the swivel tube. The internal pressure that actually occurs during conveyance is in turn largely dependent on the ultimate conveying task, e.g. the material to be conveyed, the length of the conveying section and/or the height difference to be overcome.

In order to be able to ensure the seal between the delivery cylinder and the swivel pipe over the entire possible operating range of a two-cylinder high-density pump, the cutting ring and automatic ring are designed according to the state of the art for the minimum internal pressure to be expected. Due to the linearity between the internal pressure and the contact pressure, however, this has the consequence that the contact pressure is regularly significantly higher at higher internal pressures caused by the conveyance than would actually be required for the desired seal.

At the same time, it can be observed that the internal pressure in question decreases briefly when a two-cylinder sludge pump is in operation, even after the pressure stroke by a delivery cylinder has taken place, but does not regularly drop to zero due to the material pushing back out of the delivery line. As a result, the cutting ring is also pressed against an opposite surface during the pivoting of the pivot tube. If this contact pressure and the resulting friction during pivoting can be overcome at low delivery pressures, at higher delivery pressures the contact pressure during Pivoting cause friction due to the remaining internal pressure that is difficult or impossible to overcome and with extreme material wear.

A swivel pipe designed according to the state of the art can thus become the limiting factor of a diverter valve and thus of a concrete pump with regard to the permissible delivery pressure range.

The object of the invention is to create a swivel tube arrangement for two-cylinder sludge pumps and a transfer tube and a two-cylinder sludge pump, each with a swivel tube arrangement, in which the disadvantages of the prior art no longer occur or only occur to a lesser extent.

This object is achieved by a swivel pipe arrangement according to claim 1, an arrangement comprising a diverter pipe according to claim 8 and a two-cylinder thick matter pump according to claim 9.

The invention has recognized that, among other things, for reasons of cleaning in a two-cylinder sludge pump with diverter valve, the pivoting tube can regularly be easily removed or at least exposed, which means that the cutting ring on the pivoting tube is also easily accessible. The invention makes use of this circumstance in that the automatic ring provided according to the invention is part of an automatic ring arrangement which is easy to exchange and in which, in addition to the automatic ring, there is also an insert ring radially surrounding the automatic ring. Because the automatic ring is surrounded by an insert ring, it's done Appropriate choice of the thicknesses of automatic and Einlagerring possible to create different automatic ring arrangement, which each have identical external and internal dimensions and are therefore easily interchangeable, in which the thickness or radial extent of the automatic ring can be different but so different To achieve links between internal pressure in the swivel tube and contact pressure on the cutting ring. The automatic ring arrangement can be adapted to the internal pressure to be expected both during a pressure stroke and during the pivoting of the pivoting tube so that on the one hand adequate sealing between the pivoting tube and delivery cylinder is ensured and on the other hand the friction during pivoting is kept sufficiently low. If it is easy to replace, the automatic ring arrangement suitable for a specific pumping task can also be used directly at the place of use of the two-cylinder sludge pump - e.g. on the construction site if the two-cylinder sludge pump is used as a concrete pump.

It is possible that the automatic ring and the storage ring of the automatic ring arrangement are separate components. The two rings are therefore only detachably connected - if at all - so that the automatic ring in particular can be easily replaced if it is worn. When the two rings are completely detached from each other, they can be inserted into the swivel tube one after the other and only form the automatic ring arrangement in situ.

In the latter case in particular, the storage ring can comprise a number of ring segments, ie a number of individual segments which together form the storage ring. The individual ring segments can then be inserted one after the other into an undercut - e.g. a circumferential groove - in the swivel tube, so that the completed insert ring is secured in the axial direction. The individual ring segments can be secured in the undercut by the automatic ring then to be inserted radially on the inside, in that the elastic automatic ring presses the ring segments slightly into the undercut or at least does not allow them to slide out.

Alternatively, it is possible for the automatic ring and the insert ring of the automatic ring assembly to be integrated - i.e. H. inextricably linked components are. In this case, as in the case of a detachable connection between the automatic ring and the storage ring (see above), the automatic ring assembly can be inserted completely and in one step into the swivel tube. In this case, in which an arrangement in an undercut is regularly ruled out, the automatic ring arrangement can be secured by separate fastening means in the swivel tube. If the cutting ring is movably secured to the swivel tube, the automatic ring arrangement may not require a separate safeguard. The automatic ring arrangement is then sufficiently secured by its position between the swivel tube and the cutting ring.

Depending on how the radial expansions of the automatic rings of different automatic ring arrangements differ from one another, it may be necessary to use a cutting ring that is adapted to the shape of the automatic ring. It can therefore be preferred if the cutting ring is part of the interchangeable automatic ring arrangement and the side of the cutting ring facing the automatic ring is adapted to the radial extension of the automatic ring of the automatic ring arrangement. In this case, when the automatic ring arrangement is exchanged, the cutting ring is also exchanged as part thereof, so that a cutting ring that matches the automatic ring of the arrangement is always used.

Irrespective of whether the cutting ring is part of the automatic ring arrangement, it is preferred if the cutting ring has a radially outer shielding element for protecting the inlet side of the swivel tube, the shielding element preferably being conically shaped and/or concavely curved. A corresponding shielding element can be used to prevent thick matter flowing after a delivery cylinder when the pivoting tube is pivoted from directly hitting the inlet side or end face of the pivoting tube. Rather, the thick matter can be routed around the inlet side of the swivel tube through the shielding element.

The automatic ring can be made of synthetic rubber, preferably chloroprene rubber. The insert ring is preferably made of steel. The cutting ring is preferably made of hard metal, preferably tungsten carbide, at least in the area that temporarily interacts with the sealing surface and/or on the outside of the shielding element. For this purpose, suitable hard metal inserts or attachments can be provided, which are arranged on a component that is otherwise made of steel.

For an explanation of the swivel pipe arrangement according to the invention, the diverter valve according to the invention and the two-cylinder thick matter pump according to the invention, reference is made to the above statements.

The invention is particularly suitable for use in or as concrete pumps, the thick matter to be pumped being free-flowing concrete.

Figur 1:

eine schematische Darstellung einer erfindungsgemäßen Zweizylinder-Dickstoffpumpe mit Rohrweiche umfassend ein erfindungsgemäßes Schwenkrohr;

Figur 2:

eine Schnittansicht des Schwenkrohrs aus Figur 1;

Figur 3:

eine Schnittansicht des Schwenkrohrs aus Figur 2 mit ausgetauschter Automatikringanordnung; und

Figur 4:

eine schematische Draufsicht auf die Einlassöffnung des Schwenkrohrs gemäß Figur 3 unter Weglassung des Schneidrings.

The invention will now be described by way of example on the basis of an advantageous embodiment with reference to the accompanying drawings. Show it:

Figure 1:

a schematic representation of a two-cylinder sludge pump according to the invention with a diverter valve comprising a swivel pipe according to the invention;

Figure 2:

Figure 12 shows a sectional view of the pivot tube figure 1 ;

Figure 3:

Figure 12 shows a sectional view of the pivot tube figure 2 with exchanged automatic ring arrangement; and

Figure 4:

a schematic plan view of the inlet opening of the pivot tube according to FIG figure 3 omitting the cutting ring.

figure 1 shows a schematic representation of a two-cylinder sludge pump 1. The sludge pump 1 has two delivery cylinders 2, 3, in each of which pistons 4, 5 are guided and operated alternately in such a way that one piston 4 performs a suction stroke (indicated by arrow 6), while the other piston 5 exerts a pressure stroke (see arrow 7).

Arranged in a common spectacle plate 8 free openings 9 of the delivery cylinders 2, 3 protrude into a material feed container 10, in which the thick material to be conveyed, for example free-flowing concrete, is given up. If the opening 9 of a delivery cylinder 2 is free during the suction stroke, thick material passes from the material output container 10 into the delivery cylinder 2.

A diverter valve 11 connected to the conveying line 13 is also arranged in the material feed container 10 . The transfer tube 11 comprises a pivoting tube 20 that can be pivoted via a diverter drive 12. The pivoting tube 20 is pivoted in time with the two-cylinder thick matter pump 1 in such a way that its inlet opening 21 is always connected to the opening 9 of the delivery cylinder 3 that is currently performing the pressure stroke 7 executes, so that the thick matter in the cylinder 3 is conveyed into the delivery line 13. The opening 9 of the other suction delivery cylinder 2 is free, so that thick matter can get into this delivery cylinder 2, as described.

In figure 2 the swivel tube 20 of the two-cylinder thick matter pump 1 is off figure 1 shown in more detail. The outlet opening 22 of the swivel pipe 20, which is used for the connection to the delivery line 13, is arranged coaxially to a swivel axis 23. A pivot pin 24 for connection to the transfer tube drive 12 is also provided along this pivot axis 23 .

The inlet opening 21 of the pivoting tube 20 is arranged eccentrically to the pivoting axis 23 , resulting in an S-shape for the pivoting tube 20 . Due to the eccentric arrangement of the inlet opening 21, it can be moved on a circular path via the transfer tube drive 12 in such a way that it optionally communicates with one of the two openings 9 of the delivery cylinders 2, 3.

In order to prevent thick matter from escaping between the opening 9 of the delivery cylinder 3 and the swivel pipe 20 during the pressure stroke 7 and not being delivered through the swivel pipe 20 and the delivery line 13, a cutting ring 25 is provided at the inlet opening 21, which is designed as a wear ring and is guided in the conveying line 13 in an axially displaceable manner. The cutting ring 25, which is basically made of steel, has a sealing surface 26 made of tungsten carbide on the side facing the openings 9 of the delivery cylinders 2, 3. In addition, a radially outer shielding element 27 is provided to protect the inlet side 21 of the swivel tube, which is conically shaped and also coated with tungsten carbide.

In order to achieve the desired seal, the cutting ring 25 must be pressed with its sealing surface 26 against a sealing surface 9' which surrounds the openings 9 in a circle on the spectacle plate 8. To accomplish this, an interchangeable auto ring assembly 30 is provided.

The automatic ring arrangement 30 comprises an automatic ring 31 made of chloroprene rubber, which is supported by one of several ring segments 33 (cf. figure 4 ) existing storage ring 32 is surrounded. Automatic ring 31 and insert ring 32 are not structurally connected to one another, but only form the automatic ring arrangement 30 in the in figure 2 installed condition shown. This is - as below in connection with figure 4 explained in more detail - first the insert ring 32 is successively inserted in segments into an undercut 28 provided on the swivel tube 20 before the one-piece automatic ring 31 is then placed radially on the inside of the insert ring 32 . The segments 33 of the insert ring 32 are thus secured in the undercut 28 . The automatic ring 31 is in turn secured by a locking ring 34 to be finally inserted and firmly connected to the swivel tube 20 .

The cutting ring 25 bears against the automatic ring 31 in the axial direction, with a gap being provided between the cutting ring 25 and the securing ring 34, into which the thick matter to be conveyed can penetrate. If the thick matter is conveyed through the swivel pipe 20 by a pressure stroke 5, the internal pressure in the swivel pipe 20 increases Expansion in the axial direction leads. The internal pressure increases the axial force exerted on the cutting ring 25, which ultimately forms the contact pressure of the sealing surface 26 of the cutting ring 25 on the sealing surface 9' around the openings 9 in the spectacle plate 8. But even if no thick material is currently being conveyed through the swivel tube 20, a certain internal pressure remains, so that a certain, albeit significantly lower, contact pressure also prevails here.

The automatic ring arrangement 30 must be selected so that the contact pressure in the latter case is sufficiently low to still be able to pivot the pivoting tube 20, while in the case of active delivery through the pivoting tube 20 the contact pressure avoids an undesired escape of thick matter. In order to be able to combine both requirements, an automatic ring arrangement 30 is fundamentally limited to a predetermined delivery pressure range, which ultimately also represents a limiting factor for the transfer tube 11 or the two-cylinder thick-material pump 1 .

The relationship between the internal pressure in the swivel tube 20 and the contact force or contact pressure is u. depends on the radial expansion of the automatic ring 31 . Since, according to the invention, not only the automatic ring 31 is exchangeable, but rather this is only part of an overall exchangeable automatic ring arrangement 30, which also includes an insert ring 32, a different delivery pressure range can be achieved by simply exchanging the automatic ring arrangement 30, in order to also have the diverter valve 11 or the two-cylinder thick matter pump 1 can be used for other delivery pressures.

In figure 3 the swivel tube 20 is off figure 2 shown, but with the automatic ring assembly 30 replaced.

The auto ring assembly 30 off figure 3 has identical outside and inside diameters as that automatic ring assembly 30 figure 2 on, so that no changes are necessary, in particular on the swivel tube 20 and on the retaining ring 34 . The automatic ring arrangement 30 according to FIG figure 3 is also basically identical to the one from figure 2 constructed - that is, comprising a segmented insert ring 32' and an automatic ring 31' to be used separately. However, in this automatic ring arrangement 30, the radial extent of the automatic ring 31' is significantly less than in the automatic ring arrangement 30 according to FIG figure 2 . In order to nevertheless achieve the same external and internal dimensions for the automatic ring arrangement 30, the insert ring 32' has a correspondingly increased radial extent. Due to the changed geometry of the automatic ring 31', the connection between the internal pressure in the swivel tube 20 and the contact pressure is also changed.

In the case of the automatic ring arrangement 30, according to figure 3 a cutting ring 25 with opposite figure 2 slightly modified geometry. The cutting ring 25 or the two different cutting rings 25 from FIGS. 2 and 3 can be regarded as part of the automatic ring arrangement 30 and can be exchanged together with the automatic ring 31 and the storage ring 32 if required for a different delivery pressure range.

In figure 4 12 is a plan view of the inlet port 21 of the pivot tube 20 in FIG figure 3 shown, in which, however, the representation of the cutting ring 25 was completely dispensed with in order to be able to recognize the automatic ring arrangement 30 .

The insert ring 32 to be used first when assembling an automatic ring arrangement 30 comprises four ring segments 33, each with beveled ends, which are inserted one after the other into the undercut 28 (can be seen in the area of the plugged openings 29 discussed below). The last ring segment 33 to be inserted is thus first inserted with one end under the adjacent ring segment 33 (indicated by arrow 90) and then pressed with the other end into the undercut 28 (see arrow 91), whereby a closed insertion ring 32 is created. Then automatic ring 31 and locking ring 34 are used before the cutting ring 25 (not shown here) is mounted.

Dismantling is carried out in reverse order. First the locking ring 34 is removed before the automatic ring 31 can be removed. In order to release at least the first of the ring segments 33 of the insertion ring 34, plugged openings 29 are provided, which are closed by a plug (not shown) during normal operation in such a way that thick matter in the material feed container 10 cannot penetrate. To loosen a ring segment 33, however, the plug can be removed and a thin tool (e.g. a screwdriver) can be passed through one of the openings 29 in order to loosen and remove a first ring segment 33, if necessary with the aid of a hammer. The following ring segments 33 can then be removed without any problems, since after the removal of the first ring segment 33 two ends of ring segments 33 are exposed for tool application.

Claims (9)

1. Pivoting tube arrangement comprising a pivoting tube (20) for a transfer tube (11) of a two-cylinder thick matter pump (1), wherein the pivoting tube (20) has an outlet opening (22) which is arranged coaxially with respect to the pivot axis (23) and an inlet opening (21) which is arranged eccentrically with respect to the pivot axis (23), wherein a cutting ring (25) which is in the form of a wear ring and which is intended to sealingly abut against a circular sealing surface (9') is mounted at the inlet opening (21) so as to be displaceable in an axial direction in such a way that the cutting ring (25) is pushed in the direction of the sealing surface (9') by means of a self-adjusting ring (31) composed of elastic material, which is arranged coaxially with respect to said cutting ring, when internal pressure in the pivoting tube (20) acts on the self-adjusting ring (31),
   wherein
   the self-adjusting ring (31) is part of a first self-adjusting ring arrangement (30) further comprising an insert ring (32) which radially surrounds the self-adjusting ring (31), wherein the first self-adjusting ring arrangement (30) is exchangeable, characterized in that the arrangement comprises an electively usable second self-adjusting ring arrangement (30), wherein the outer and inner diameter of the two self-adjusting ring arrangements (30) are identical, but the radial extent of the self-adjusting ring (31') of the second self-adjusting ring arrangement (30) is lower than that in the first self-adjusting ring arrangement (30).
2. Pivoting tube arrangement according to Claim 1,
   characterized in that
   the self-adjusting ring (31) and the insert ring (30) of the self-adjusting ring arrangement (30) are separate components.
3. Pivoting tube arrangement according to Claim 2,
   characterized in that
   the insert ring (32) comprises a plurality of ring segments (33) which are designed to be inserted one after the other into an undercut (28) in the pivoting tube (20) and which are secured in the undercut (28) by the subsequently inserted self-adjusting ring (31).
4. Pivoting tube arrangement according to Claim 1,
   characterized in that
   the self-adjusting ring (31) and the insert ring (32) of the self-adjusting ring arrangement (30) are integrated components.
5. Pivoting tube arrangement according to one of the preceding claims,
   characterized in that
   the cutting ring (25) is part of the exchangeable self-adjusting ring arrangement (30) and that side of the cutting ring (25) which faces the self-adjusting ring (31) is adapted to the radial extent of the self-adjusting ring (31) of the self-adjusting ring arrangement (30).
6. Pivoting tube arrangement according to one of the preceding claims,
   characterized in that
   the cutting ring (25) has a radially external shielding element (27) for protecting the inlet side (21) of the pivoting tube (20), wherein the shielding element (27) is preferably of conical form and/or concavely curved.
7. Pivoting tube arrangement according to one of the preceding claims,
   characterized in that
   the self-adjusting ring (31) is composed of synthetic rubber, preferably chloroprene rubber, the insert ring (32) is composed of steel, and/or the cutting ring (25) is composed of hard metal, preferably of tungsten carbide, at least in the region (26) which intermittently cooperates with the sealing surface (9') and/or on the outer side of the shielding element (27).
8. Arrangement comprising a pivoting tube arrangement according to one of Claims 1 to 7 and a transfer tube (11) for two-cylinder thick matter pumps (1), wherein the transfer tube (11) has a spectacle wear plate (8) with two openings (9) which are surrounded by sealing surfaces (9') and which are intended for communicating connection to a respective conveying cylinder (2, 3), and a pivoting tube (20) which is pivotable back and forth, by way of its inlet opening (21), between the two openings (9) of the spectacle wear plate (8),
   characterized in that
   the first or second self-adjusting ring arrangement (30) is inserted into the pivoting tube (20), wherein the cutting ring (25) is configured to electively sealingly abut against one of the sealing surfaces (9') surrounding the openings (9).
9. Two-cylinder thick matter pump (1) comprising two conveying cylinders (2, 3) and an arrangement according to Claim 8, wherein a respective conveying cylinder (2, 3) is connected in a communicating manner to an opening (9) of the spectacle wear plate (8) of the transfer tube (11) .

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