WO2003004873A1

WO2003004873A1 - Device for conveying free-flowing or bulk materials

Info

Publication number: WO2003004873A1
Application number: PCT/EP2002/006759
Authority: WO
Inventors: Hellmut Hurr; Gerald Fischer; Frank Pirwass
Original assignee: Putzmeister Aktiengesellschaft
Priority date: 2001-07-04
Filing date: 2002-06-19
Publication date: 2003-01-16
Also published as: EP1402180B1; EP1402180A1; JP2004533569A; DE50208013D1; JP4072501B2; ES2269727T3; ATE338210T1; DE10131904A1

Abstract

The invention relates to a device for conveying free-flowing or bulk materials. The inventive device comprises at least one conveyor piston (24) that can reciprocate preferably by hydraulic means (26), a support tube (30) axially guiding the conveyor piston on its peripheral surface (42), a charge compartment (20) that is axially contingent in the direction of conveyance to the guide tube and that can be charged with material to be conveyed via a feed funnel (12), and a conveyor cylinder (32) that is axially disposed in the path of reciprocation and that is connected on the input side to the charge compartment and on the output side to a discharge pipe (14). The conveyor piston, in its end position retracted into the support tube (30), releases the charge compartment towards the feed funnel while it passes through the charge compartment when advanced, thereby entraining material to be conveyed, and penetrates the conveyor cylinder (32). The invention is specifically characterized in that the support tube, on its charge compartment end, has a replaceable sealing cassette (76) whose stripping and/or sealing elements (88, 90) resting on the peripheral surface of the conveyor piston are automatically adjusted to the state of wear of the conveyor piston.

Description

Device for conveying flowable or pourable material

description

The invention relates to a device for conveying flowable or pourable conveyed material with at least one delivery piston, which can preferably be pushed back and forth by hydraulic means, with a bearing tube axially leading the delivery piston on its outer surface, with an axially adjoining the bearing tube in the conveying direction, via a feed channel or hopper with filling material that can be conveyed, and with a delivery cylinder arranged axially in the displacement path of the delivery piston, connected on the inlet side to the filling chamber and on the outlet side to a discharge tube, the delivery piston releasing the filling chamber to the feed channel or hopper in its end position retracted into the storage tube and at Feed penetrates the filling space with the conveyed material and penetrates into the feed cylinder.

In a known conveyor device of this type (EP-B-0 681 672), which is intended for the transport of metal scrap, the delivery piston designed as a plunger cylinder is guided in a sliding guide of the bearing tube. In the bearing tube near its full-room end, inward-facing grooves for receiving wiper and fine sealing rings are also screwed. The gap between the bearing tube and the delivery piston is supplied with lubricating oil via lubrication holes in a central lubrication system. The piston penetrating into the feed cylinder lies against the wall on the inlet side, so that a vacuum is created with each return stroke. In order to ensure that no material is sucked back from the feed pipe into the filling chamber during the return stroke, a cross slide is arranged in the feed pipe behind the feed cylinder, which is closed before each return stroke of the feed cylinder and opened again before each pressure stroke. The high susceptibility to wear in the area of the bearing tube is a disadvantage considered. In addition, the known conveying device is not readily suitable for conveying the material to be conveyed from a pressurized filling space into an atmospheric outside space without the risk of a pressure breakthrough.

The invention has for its object to improve the known conveyor device in such a way that the sealing of the bearing tube against the filling chamber is improved and maintenance is made easier.

To achieve this object, the combination of features specified in claim 1 is proposed. Advantageous refinements and developments of the invention result from the dependent claims.

The solution according to the invention is based primarily on the idea that the bearing tube carries an exchangeable sealing cassette at its full-space end, the stripping and / or sealing elements which bear against the outer surface of the delivery piston can be adapted automatically to the state of wear of the delivery piston. In order to achieve this, it is proposed according to an advantageous embodiment of the invention that the sealing cassette is clamped in a floating manner between elastomeric sealing rings in a recess in the bearing tube end on the full space side. The sealing cassette expediently has a rigid, ring-shaped base body, with circumferential grooves on the inside of the base body for receiving a radially adjustable scraper and / or a radially adjustable fine seal.

A preferred embodiment of the invention provides that the scraper and / or the fine seal are composed of a plurality of segments which are divided in the circumferential direction and which each abut against a radially outer elastomeric sealing ring and can be acted upon radially with a pressure medium indirectly via the latter. With this measure it is possible to bridge wear-related removal in the area of the delivery piston and the sealing cassette within wide limits. The segments of the scraper and / or the fine seal expediently have grooves which complement one another in the circumferential direction to accommodate a closed elastomeric retaining ring, the scraper segments and / or fine sealing segments being supported in the region of the elastic retaining ring against the associated radially outer sealing ring.

A further preferred embodiment of the invention provides that the circumferential grooves for the scraper and the fine seal are limited by an insert ring arranged in an annular recess in the base body. With the insert ring, complicated installation structures can be realized that are accessible for easy maintenance. With this measure, it is also possible that the circumferential grooves for the wiper segments and for the fine sealing segments can be acted upon separately by pressure medium via channels in the base body and / or in the insert ring. For this purpose, the insert ring can be provided with ring channels for the circumferential grooves delimiting the pressure medium supply and open to the edge of an annular surface of the base body, the circumferential grooves for the pressure medium supply being able to be sealed off from one another and to the outside by sealing rings arranged in adjacent circumferential grooves. This makes it possible to press the wiper segments and the fine sealing segments against the outer surface of the delivery piston with different contact pressure.

To improve the wiping effect and / or sealing effect, it is advantageous if the segments of the wiper and / or the fine seal have overlapping steps in the circumferential direction. To improve the sealing effect, the fine sealing segments can also be composed of two elastomeric segment parts with different hardness. The base body can also have at least one on its inner surface further circumferential groove for receiving a grooving ring and / or an elastomeric guide band.

Because of the segmentation of the scraper and the fine seal, it has proven to be advantageous that the sealing cassette for assembly purposes is equipped with a central mounting tube holding the segments of the scraper and / or the fine seal against the base body, which during assembly is pushed onto the delivery piston during assembly can be pushed out of the sealing cassette. This simplifies the handling of the sealing cassette during assembly and maintenance.

A further preferred embodiment of the invention provides that the delivery piston on the bearing tube is supported and guided axially centrally via guide rollers made of an elastically deformable material. The delivery piston is expediently designed as a hydraulically displaceable plunger. In order to avoid sucking back of material to be conveyed in the feed cylinder, it is expedient for the feed piston to engage in the feed cylinder with radial play and for the feed cylinder to have an inner surface which is wavy or polygonal in the circumferential direction.

The invention is explained in more detail below on the basis of an exemplary embodiment shown schematically in the drawing. Show it

1a shows a diagrammatic representation of a spoil discharge lock for use in tunnel construction;

1b and 1c show a side view and a top view of the discharge lock according to FIG. 1a with the feed hopper placed on the filling space; 1d shows a side view of a tunnel boring machine with discharge lock according to FIGS. 1a to c;

2a to c show two longitudinal sections offset by 90 ° with respect to one another and a cross section of the delivery piston designed as a plunger cylinder of the discharge device according to FIGS. 1a to c;

3a and b show an end view and a side view of the full-space side sealing cassette of the bearing tube;

3c shows a section along the section line A - A of FIG. 3a;

4a to e an enlarged detail from FIG. 3c in different

Section planes A to E of Fig. 3a;

Fig. 5a is a plan view of the segmented scraper ring

Sealing cassette according to Fig. 4a to e;

5b shows a plan view of one of the cutting ring segments according to FIG. 5a;

5c shows a section along the section line A - A of FIG. 5b;

6a and b show a side view and an inside view of a segment of the fine seal according to FIGS. 4a to e;

7a to d a guide roller of the bearing tube of the discharge lock according to Fig. 1a to c in a diagrammatic representation and in three side views. The discharge lock 8 shown in the drawing is intended for use in tunnel boring machines 1. For this purpose, it has an obliquely upwardly directed flange plate 10 and a feed hopper 12, with which it can be connected to a transport pipe 3 equipped with a screw conveyor 2 for the waste 5 accumulating in the excavation chamber 4 of the tunnel boring machine 1. The earthy or rocky overburden 5, which as a rule cannot be pumped, is fed to the discharge lock 8 under a pressure p> p _atm which is increased due to the pressure, and is discharged via the discharge pipes 14 against atmospheric pressure p _atm for further conveyance, for example, via further discharge a belt conveyor 6 discharged. The two hooks 16 arranged in the vicinity of the flange plate 10 serve to facilitate assembly and maintenance.

In the exemplary embodiment shown, the discharge lock 8 has two conveying devices or lock parts 18 which operate in push-pull and which are constructed essentially the same. The two lock parts each contain a filling space 20, which are separated from one another by a partition 22 and can be fed with conveyed material via the common feed hopper 12. In each lock part there is a delivery piston 24 designed as a plunger, which can be pushed back and forth via a hydraulic drive cylinder 26. A support cage 28, a bearing tube 30, one of the filling chambers 20, a delivery cylinder 32, an intermediate tube 34 with a cross slide 36 and one of the discharge tubes 14 are assigned axially one behind the other to each delivery piston 24. In their end position, which is retracted into the bearing tube 30, the delivery pistons 24, which can be driven in push-pull, release the filling chamber 20 to the feed hopper and penetrate into the respective delivery cylinder 32 when the material is conveyed and is taken from the filling chamber 20. The material to be conveyed is compressed in the delivery cylinder 32, in the subsequent intermediate tube 34 and in the discharge tube 14 to form a plug so that it forms an airtight seal between the filling space 20 and the outside half of the outlet opening 38 of the discharge tube 14 comes outside.

With each delivery stroke, part of the plug is displaced outward via the outlet opening 38. Knife-like separating elements 40 are located in the outlet opening 38, which break up and break up the emerging plug section. With each conveying stroke, the plug is replaced by compressed material to be conveyed.

At the beginning of a funding process, if there is no grafting, a grafting must first be built up. For this purpose, the two cross slides 36 are provided, which are offset from one another in the axial direction for reasons of space. First, the cross slide is brought into its closed position. The material to be conveyed is then pressed with the respective delivery piston 24 with reduced feed force against the cross slide 36 engaging in the feed path within the intermediate tube 34 and thereby compressed to form a plug. The displacement path of the delivery piston 24 is monitored by a displacement measuring system 62, 64 connected to the hydraulic drive cylinder 26. As soon as a sufficient plug has been built up, the cross slides 36 are opened and the plugs are moved into the associated discharge tube 14 during the subsequent conveying strokes of the conveying piston 24 until they reach the outlet opening 38. In order to influence the formation of a plug, depending on the consistency of the conveyed material, and to support an existing plug, it is possible to use diaphragms (not shown) with different opening cross sections in the area of the outlet openings 38.

In order to avoid the formation of a vacuum when the piston is withdrawn from the cylinder, which could lead to the plug being broken up, delivery pistons 24 and delivery cylinders 32 are dimensioned such that a gap for air passage between the filling space 20 and the intermediate pipe is formed between them 34 remains free. The inner surface of the discharge pipe, the intermediate pipe and possibly also the delivery cylinder are equipped with wear strips, which are screwed detachably from the outside through the respective pipe wall. The wear strips complement each other to form a non-circular cross-section, preferably a polygonal inner surface.

As can be seen from FIGS. 2a to c, the lateral surface 42 of the delivery piston 24 is formed by an elongated hollow cylinder 44, the free end face of which is closed by an end plate 46 and in which the hydraulic drive cylinder 26 is located. The cylinder part 48 of the drive cylinder 26 is articulated on its base part 50 via a hinge 52 at the rear end of the support cage 28 and is supported and guided on the rod end via two support rollers 54, which are at an angular distance of 90 ° from one another, on the inner surface of the hollow cylinder 44 , The piston rod 56 of the drive cylinder is articulated on the inside of the end plate 46 via a joint 58. The hinge axes of the joints 52 and 58 are perpendicular to one another and aligned with the direction of displacement of the piston rod 56. The piston rod 56 has an axis-central cavity 60, into which a stainless steel tube 62, which protects a waveguide and which is fixed at the bottom end of the cylinder part, engages axially centrally. The waveguide 62, together with a permanent magnet 64 fixed to the piston rod, forms the displacement measuring system with which the instantaneous displacement position of the delivery piston 24 can be measured.

The support piston 24 is supported and guided axially centrally within the bearing tube 30. For this purpose, guide rollers 66 are arranged on the outside of the bearing tube, and their running surface 68 extends through wall openings of the bearing tube in the direction of the outer surface 42 of the delivery piston. The guide rollers 66, which are made of an elastomeric material, preferably of heavy-duty polyamide, are each mounted on a bearing block 70. Each bearing block is fixed at one end to a bearing tube Swivel bearing 72 is articulated and screwed to the bearing tube 30 at its other end with a spring-assisted screw 74. The running surface 68 of the guide rollers has a concave transverse curvature which is complementary to the outer surface 42 of the delivery piston 24 (FIG. 7c). As can be seen from FIGS. 1 a to c, the guide rollers are arranged in three axial positions spaced apart from one another and in three circumferential positions spaced apart from one another in the circumferential direction, each circumferential position being equipped with two guide rollers arranged next to one another. The feed piston 24 is dimensioned such that it moves out of the region of the guide rollers 66 located in the rear axial position when it is moved into the feed cylinder 32.

At its full space end, the bearing tube 30 has a sealing cassette 76, which is clamped in a floating manner between two O-rings 78, 80 in a recess of the bearing tube end with the aid of a clamping ring 82 and is easily exchangeable. The sealing cassette 76 has a metallic annular base body 84, which is provided on the inside with circumferential grooves 86 for receiving a radially adjustable wiper 88 and a radially adjustable fine seal 90 made of elastomeric material. The circumferential grooves 86 for the wiper 88 and for the fine seal 90 are delimited by an insert ring 94 arranged in an annular recess 92 in the base body 84. As can be seen from FIGS. 5a to c, 6a and b, the wiper 88 and the fine seal 90 are composed of several segments 88 ', 90' divided in the circumferential direction, each against a radially outer elastomeric ring 96, 98 apply, and can be acted upon indirectly with a pressure medium, for example with grease. The segments 88 ', 90' of the scraper 88 and the fine seal 90 have mutually complementary grooves for receiving a closed elastomeric retaining ring 104, 106 and are supported in the region of the retaining ring against the associated radially outer sealing ring 96, 98. To ensure that the segments 88 ' 88 'of the scraper 88 in the circumferential direction, they are fixed in the circumferential direction with the aid of pins 130 inserted into the insert ring 94 via the recesses 132 in the segments 88' (see FIGS. 5a to c and 4a and d) , It can be seen in FIG. 6 b that the fine sealing segments 90 ′ have steps 120 that overlap one another in the circumferential direction. In addition, the fine sealing segments 90 'are composed of two elastomeric segment parts 90 ", 90'" with different hardness. The circumferential grooves 86 for the wiping segments 88 'and the fine sealing segments 90' can be acted upon independently of one another with pressure medium via channels 108, 110 in the base body. For this purpose, the insert ring is also provided with ring channels for the circumferential grooves 112, 114 which delimit the pressure medium supply and open to the edge of an annular surface 116 of the base body. The circumferential grooves 112, 114 are sealed off from one another and to the outside by sealing rings 118 arranged in adjacent circumferential grooves.

Another channel 122 is used to supply a lubricant or flushing agent. On its inner surface, the base body has further circumferential grooves for receiving a grooved ring 124 and an elastomeric guide band 126.

The sealing cassettes 76 can be prefabricated and exchanged as a whole. In order to hold the segmented wipers 88 and fine seals 90 as well as the grooved rings 124 and guide bands 126 in position in the prefabricated state, a mounting tube 128 is provided which is pushed out of the sealing cassette during the assembly process when the sealing cassette 76 is pushed onto the delivery piston 24.

In summary, the following can be stated: The invention relates to a device for conveying flowable or pourable material to be conveyed. It points at least one, preferably with hydraulic means 26 slide-out delivery piston 24, a bearing tube 30 axially guiding the delivery piston 24 on its outer surface 42, a filling chamber 20 adjoining the bearing tube axially in the conveying direction, which can be filled with material to be conveyed via a feed funnel 12, and an axially arranged in the displacement path of the delivery piston 24 on the inlet side to the filling chamber 20 and on the output side connected to a discharge pipe 14 delivery cylinder 32. The feed piston 24, in its end position retracted into the bearing tube 30, frees the filling space 20 to the feed hopper 12, while during the feed it penetrates the filling space 20 with the conveyed material being carried and penetrates into the feed cylinder 32. To improve the sealing of the bearing tube 30 with respect to the filling chamber 20 and to facilitate maintenance, it is proposed according to the invention that the bearing tube 30 carries at its full-chamber end an exchangeable sealing cassette 76, the wiping and / or bearing against the lateral surface 42 of the delivery piston 24 Sealing elements 88, 90 are automatically adaptable to the wear state of the delivery piston 24.

Claims

claims

1. Device for conveying flowable or pourable conveyed material with at least one delivery piston (24), which can preferably be pushed back and forth by hydraulic means, with a bearing tube (30) axially leading the delivery piston (24) on its lateral surface (42), with one to the Bearing tube (30) axially adjoining in the conveying direction, filling space (20) which can be fed with conveyed material via a feed channel or funnel (12) and with an axially arranged in the displacement path of the conveying piston (24), on the inlet side to the filling chamber (20) and on the outlet side to a discharge tube (14) connected feed cylinder (32), the feed piston (24) in its end position retracted into the bearing tube (30) releasing the filling space (20) to the feed channel or funnel (12) and during feeding the filling space (20) with takes penetration of material to be conveyed and penetrates into the conveyor cylinder (32), characterized in that the bearing tube (30) has a thaw at its end on the full-space side The sealable cassette (76) carries, the sealing and / or wiping elements (88, 90) which bear against the lateral surface (42) of the delivery piston (24) can be adapted automatically to the state of wear of the delivery piston (24).

2. Device according to claim 1, characterized in that the sealing cassette (76) floating between elastomeric sealing rings (78, 80) is clamped in a recess of the full-space bearing tube end.

3. Apparatus according to claim 1 or 2, characterized in that the sealing cassette (76) has a rigid annular base body (84), and that on the inside of the base body circumferential grooves (86) for receiving a radially adjustable scraper (88) and / or a radial adjustable fine seal (90) are arranged.

4. The device according to claim 3, characterized in that the scraper (88) and / or the fine seal (90) are composed of several segments (88 ', 90') divided in the circumferential direction, each against a radially outer elastomer Sealing ring (96, 98) abut and can be acted upon radially with a pressure medium indirectly.

5. The device according to claim 4, characterized in that the segments (88 ', 90') of the scraper (88) and / or the fine seal (90) in the circumferential direction complementary grooves (100, 102) for receiving a closed elastomeric retaining ring ( 104, 106).

6. The device according to claim 5, characterized in that the stripping segments (88 ') and / or fine sealing segments (90') in the region of the elastomeric retaining ring (104, 106) are supported against the associated radially outer sealing ring (96, 98).

7. Device according to one of claims 3 to 6, characterized in that the circumferential grooves (86) for the wiper (88) and the fine seal (90) through an in an annular recess (92) of the base body (84) arranged insert ring (94 ) are limited.

8. Device according to one of claims 3 to 7, characterized in that the circumferential grooves (86) for the wiping segments (88 ') and for the fine sealing segments (90 ") via channels (108, 110) in the base body (84) and / or in the insert ring (94) can be acted upon separately with the pressure medium.

9. Apparatus according to claim 7 or 8, characterized in that the insert ring (94) is provided with ring channels for the pressure medium supply, to an annular surface (116) of the base body (84) edge-open peripheral grooves (112, 114).

10. The device according to claim 9, characterized in that the circumferential grooves (112, 114) for the pressure medium supply by means of sealing rings (118) arranged in adjacent circumferential grooves are sealed against one another and towards the outside.

11. Device according to one of claims 4 to 10, characterized in that the segments (88 ', 90') of the scraper (88) and / or the fine seal (90) have mutually overlapping steps (120) in the circumferential direction.

12. The device according to one of claims 4 to 11, characterized in that the fine sealing segments (90 ') from two elastomeric segment parts (90 ", 90'") are composed of different hardness.

13. Device according to one of claims 1 to 12, characterized in that the base body (84) has on its inner surface at least one further circumferential groove for receiving a grooving ring (124) and / or an elastomeric guide band (126).

14. Device according to one of claims 4 to 13, characterized in that the sealing cassette (76) with one of the segments (88 ', 90') of the wiper (88) and / or the fine seal (90) against the base body (84) holding central mounting tube (128) are fitted, which can be pushed out of the sealing cassette (76) in the course of assembly when pushed onto the delivery piston (24).

15. Device according to one of claims 1 to 14, characterized in that the sealing cassette (76) via an end clamping ring (82) with intermediate clamps of axially acting elastomeric rings (78, 80) on the bearing tube (30) can be fixed.

16. The device according to one of claims 4 to 15, characterized in that the segments (88 ', 90') of the scraper (88) and / or the fine seal (90) with the base body (84) and / or the insert ring (94) are secured against rotation, in particular pinned.

17. The device according to one of claims 1 to 16, characterized in that the delivery piston (24) is designed as a hydraulically displaceable plunger.

18. Device according to one of claims 1 to 17, characterized in that the delivery piston (24) on the bearing tube (30) via guide rollers (66) made of an elastically deformable material is supported and guided axially.

19. The device according to one of claims 1 to 18, characterized in that the delivery piston (24) engages with radial play in the delivery cylinder (32).

20. Device according to one of claims 1 to 19, characterized in that the conveying cylinder (32) has a wavy or polygonal inner surface in the circumferential direction.