EP0034604A1

EP0034604A1 - Device in pipe conveyors

Info

Publication number: EP0034604A1
Application number: EP80901584A
Authority: EP
Inventors: Jan Odd Bogen
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-08-13
Filing date: 1981-02-24
Publication date: 1981-09-02
Also published as: SE7906760L; WO1981000394A1

Abstract

Nouveau dispositif pour un transporteur en forme de tube destine au transport de materiaux en morceaux, en vrac, ce transporteur consistant en un tube transporteur rotatif (36) avec au moins une bride helicoidale (38) fixee a la paroi interne du tube pour mettre en mouvement le materiau en vrac (16) a partir de l'ouverture d'entree (37) du tube vers une ou plusieurs ouvertures de sortie (39) du materiau en vrac, le tube transporteur etant supporte de maniere pivotante par un arbre transversal (58, 70, 72). Il absorbe, par son extremite d'entree en porte-a-faux (27) le materiau en vrac en morceau et eventuellement des particules plus fines et du liquide. La nouvelle caracteristique essentielle de ce dispositif consiste en ce qu des moyens (50, 98) sont prevus pour entourer et/ou enfermer le tube transporteur (36) et limiter ses mouvements de pivotement maximum au moins horizontalement. Le tube transporteur (36) est egalement approprie pour etre supporte et tourillonne en rotation continue dans un seul palier (56).New device for a tube-shaped conveyor intended for the transport of pieces of loose material, this conveyor consisting of a rotary conveyor tube (36) with at least one helical flange (38) fixed to the internal wall of the tube for placing movement of the bulk material (16) from the inlet opening (37) of the tube towards one or more outlet openings (39) of the bulk material, the conveyor tube being pivotally supported by a transverse shaft ( 58, 70, 72). It absorbs, by its cantilevered entry end (27) the loose material in pieces and possibly finer particles and liquid. The new essential characteristic of this device consists in that means (50, 98) are provided for surrounding and / or enclosing the conveyor tube (36) and limiting its maximum pivoting movements at least horizontally. The conveyor tube (36) is also suitable for being supported and journalled in continuous rotation in a single bearing (56).

Description

Device in pipe conveyors

The present invention relates to a pipe conveyor for pieced bulk material. Said conveyor, comprises a rotating conveyor pipe with at least one helical flange fixed to the inner wall of the pipe for moving the bulk material from the intake opening of the pipe to one or more discharge openings for the bulk material, the conveyor pipe being pivotally carried on a transverse shaft with its projecting intake end in engagement with and feeding into its interior the pieced bulk material as well as possible finer particles and liquid.

A wheel mounted pipe conveyor of similar type has been suggested previously comprising a conveyor pipe with a excavating head which has a number of toothed digging and intake means. At the discharge end, the pipe is rotatably mounted in a bearing arrangement surrounding the outside of the pipe. This bearing arrangement is in turn carried by a frame by means of essentially horizontal stub axles. Between this rear bearing point and the excavator head, there is an additional bearing arrangement on a framework carrying the pipe drive motor, which imparts the pipe its rotary movement .via a toothed rim applied on its outer surface..This pipe conveyor also comprises a lifting device for setting the excavator head in the desired vertical position.

This known pipe conveyor has, however, several disadvantages. The conveyor pipe is freely pivotable in one plane perpendicular to the stub axles, but the lateral forces arising as a reaction to the engagement of the excavator head with the bulk material produce very great stresses with subsequent wear on the bearing arrangements around the pipe. These bearing devices and.the lifting device and stub axles with their bearings in the frame must absorb all such lateral forces since there are no fixed devices for limiting the lateral movement of the pipe, in connection with the driving device or anywhere

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Λ - \ \iΫPO^~ else along the pipe. Thus the lifting device will be subjected to other types. of stresses, than those for which such devices are normally designed for.

In another known wheeled pipe conveyor, the pipe is mounted in two bearing devices which surround the pipe jacket. One of these interacts with a toothed rim to rotate the pipe. The bearing and driving devices are mounted beneath -the pipe in a frame one end of which is carried by a horizontal pivot shaft,mounted in the stand of the conveyor adjacent to the discharge end of the pipe.

A jack is arranged on the stand to raise the other end of the frame and .thereby the intake end of the pipe prior to driving the conveyor up to the pile of material which is to be loaded. The intake end is then lowered by means of the jack, so that it rests on the pile, and the jack is then lowered further so that it no longer engages the frame when the loading has begun.

The conveyor pipe has an internal. flange fixed to the pipe wall and on its outside has a second conveyor flange with an oppositely directed pitch on the portion of the pipe closest to the intake opening. As the pipe rotates, this second conveyor flange will move the materia towards the intake opening of the pipe at the same time as the internal flange moves the material through the pipe. in this manner the take up zone of the pipe conveyor is extended axially. During loading the pipe will eat its way down in the pile of material until it reaches the lowest possible bottom position whereupon it is lifted with the aid of the jack and the entire pipe conveyor is moved to a new position.

This known pipe conveyor also has several dis¬ advantages. All of the lateral forces must be absorbed by the two bearing arrangements, which are thus subjected to unnecessarily large stresses, and excessive wear. Since the pivot axis of the conveyor pipe is located lower than the rotational axis of the same, all of the lateral forces on the bearing arrangements will cause shear.stresses in the frame, which in time can result in permanent deformation of the same.

In both of the known pipe conveyors, both the bearings -and the gear. rims are quite unprotected against penetration by the loaded material, especially in view of the fact that the intake endsof. the conveyor pipes can be directed upwards at the beginning of. a loading cycle. The toothed rims on the pipe jacketsfor driving the pipes are in a very vulnerable position since particles of material can come.in between the teeth resulting in rapid wear and possible tooth breakage. This would also occur even if a protective enclosure is arranged around the gear mechanisms, since it is very difficult to make such an enclosure completely tight because the intake end of the pipe is cantalevered and freely movable.

The type of rotational bearing suggested up to now for the conveyor pipe, namely .a number of wheels, several of which have guide flanges for axial control, said wheels lying in contact with rings around the outer jacket surfaces of the pipe, is also particularly subject to wear from the loaded material, quickly resulting in too much play in such bearing arrangements.

The conveyor pipe in the known pipe conveyors is completely freely pivotable in an essentially vertical pivot plane, causing the intake end to hop and vibrate. Because of the bearing arrangement which is otherwise completely rigid throughout, these vibrations will be transmitted throughout the entire construction with subsequent risk for fatigue failure. The two previously known pipe conveyors are also quite unstable, and therefore there is a great risk that they might tip over if the pipe becomes stuck in large sized and/or compact .material. Furthermore there are no means whatsoever for limiting sudden vertical movements in the pivot plane. •

In addition to these known pipe conveyors with drive means on the jacket surface for moving solid dry material. various devices of the Archimedes screw type are known, in which the driving is done via.a. shaf at the discharg end of the pipe. This shaft also constitutes an upper bearing point. All of these devices are, however, rigidl mounted, either in a bottom bearing or in a bearing arrangement which encircles the middle portion of the pipe. Since these arrangements are intended for. pumping water, possibly containing various organic products, the are quite unsuitable for conveying inorganic..solid material. When conveying fragmented bulk material, the pieces of material, stone for example, have a tendency t be wedged tightly between the screw and the wall surrounding the intake opening. This causes heavy wear, large power requirements-due to friction, and great risk of stoppages. Furthermore these devices are quite inflex ible in their processes and it is therefore not possible to use them in connection with solid material in larger amounts than what corresponds, to the instantaneous transport capacity of the conveyor in question. A convey system comprising such a pipe conveyor thus has no buffe capacity whatsoever, and.will therefore be a bottle neck in the flow of materials in a plant.

The purpose of the present invention is to achieve a pipe conveyor of the type described in the introductio with high capacity, in which the bearing arrangements, pivot shaft, frame and drive means of the actual conveyo pipe are not subjected to damaging stresses. as a result of those lateral forces which occur upon engagement of the excavator head with the bulk material to be conveyed. Furthermore this pipe conveyor is to have, together with an accompanying receiving space for bqlk material, a certain buffer capacity which can absorb variations in the supply of material.

For this reason.the invention, is primarily charac- terized in that the conveyor pipe is surrounded by and/o enclosed in means which -limit the maximum pivot movements at least horizontally,. and preferably also vertically. In an especially advantageous embodiment of.a device made according to the invention, the conveyor, pipe is continuously carried, and mounted- for rotation in a single bearing. It is also advantageous if. the conveyor, pipe has at its discharge end an axial bearing pin for the bearing which continuously carries the pipe. This bearing pin can possibly.be tubular,, thereby permitting the passage of a stationary or rotating conduit..for. example to the interior of the conveyor pipe.

Furthermore the drive device for the..conveyor pipe can be mounted on this bearing pin.

It is also advantageous if. the pipe is mounted so that in addition to pivoting movements in the planedefined by the transverse pivot shaft, it can also move in directions at an angle to this plane. According to an advantageous embodiment of a device according to the invention, the pipe is also rotatable during. ll of its pivot movements within. the limits defined by the means which surround and/or enclose. the pipe. These means can be for example a stationary constraining bar which limits the deviation of the conveyor pipe from its normal operating position_* The constraining bar itself can be rigidly joined to a frame belonging to the conveyor. When idling or at low material load, the conveyor pipe can assume a normal lower working position, in which the pipe is supported by, in addition to the continuously supporting bearing, support rollers arranged between said bearing and the intake opening. In a device according to the invention, it is also possible to have the conveyor pipe pivotally carried and rotationally mounted in bearings and also provided with means for raising and lowering the intake end in relation to the position of the bulk material to be conveyed. To make automation possible of a pipe conveyor provided with a device according to the invention, sensor means can be provided to sense the torque of the pipe and/or a variable dependent thereon, which means then suitably, send signals to a control system for the convey The control system can be arranged. o control the raisin and lowering of the lower .end of the pipe depending on the sensed -torque or the variable dependent thereon.

A device according .to the invention comprises a pi conveyor in conjunction with a suitable receiving space for bulk material, which space should be suitably dimensioned, to receive additional amounts of bulk materi beyond the instantaneous conveyor capacity of the pipe, thus creating a buffer capacity for bulk material in a system.- Bulk material can be supplied to the conveyor during operation, not merely to its intake opening but also to the area adjacent to and above the lower end of the pipe which is suitably provided there with external stewing or conveying means. During idling or when the supply of bulk material is less than or equal to the instantaneous capacity of the conveyor pipe, the pipe is supported by the transverse shaft, the support rollers and any bulk material under the lower end of the pipe. If the receiving end of the pipe should become stuck in the material, for example if a. larger piece of material becomes wedged under the pipe, the constraining bar permi limited freedom of movement for said end to automaticall work itself away from the critical position in relation to the material by virtue of the fact that the pipe is able to swing to a certain extent within the constrainin bar and then swing down under the influence of gravity t a less strained engagement.with said material. in the receiving space. The conveyor pipe can also be pressed upwards, by a momentary .introduction of a large amount of bulk material and may then temporarily leave its normal working position on the support rollers. The maximum cha of position of the conveyor-pipe is determined by the in dimensions of the constraining bar or the means which surround and/or enclose the conveyor pipe.

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( -C. Operational tests with devices made according to the invention, have-demonstrated. the desirability of providing the lower end of the pipe with external dispersing and/or stirring means. If such means are lacking, the bulk material will form a stationary bead which is only affected insignificantly if at all by the contact with the outside of the pipe. The effect of drivers for example near the actual intake opening of the pipe is too little to cause the bulk material to move towards, the pipe intake at any appreciable speed. If the lower end of the pipe were smooth and if it were to leave its normal lower working position, it could not work itself back to said position. Thus it is a prerequisite for full utilisation of the invention that the lower end of the conveyor pipe have external dispersing and/or stirring means, which loosen the bulk material so that it can move towards the pipe intake. It is especially advantageous if these stirring and/or dispersing means are shaped so that they impart the material a component of movement in the direction towards the intake. In a device according to the invention, the lower end of the conveyor pipe has the possibility of changing its position if a large piece of material becomes wedged tightly between the conveyor pipe and the adjacent basin wall or if an excess of bulk material has temporarily been collected in the receiving space, the maximum.change in position of the pipe being determined by the inner dimensions of the means surrounding and/or enclosing the pipe. On such occasions, the conveyor pipe is supported and mounted for rotation in a single bearing. The invention will be described in the following with reference to an embodiment shown in the accompanying drawings, which demonstrates the use of the invention in an installation for recovery of aggregate material from so-called residual concrete, i.e. unused mixed concrete and rinse water from washing of the concrete carrying vehicles and mixers at concrete stations and construction sites.

_ °^U';PL Fig. 1 in the drawings is a side projection partial in section of a basic form of the invention.

Fig, 2 is an end view partially in section of Fig. showing a concrete carrying vehicle part next to the insulation.

Fig. 3 is a cross section of the conveyor pipe alon the line A-A in Fig. 1 and a projection of a so-called constraining bar and roller set for the conveyor pipe. Fig. 4 is an end view of a drive unit for the conveyor pipe as viewed in the direction of the arrow B i Fig. 1.

Fig. 5 is a modified embodiment of a part in Fig. 4 Fig. 6 is a side projection partially in section of an installation according to Fig. 1 with inclined adjusti means.

Fig. 7 is a cross sectional view in the direction o the arrow P in Fig. 6.

Figs. 1-4 illustrate a basic embodiment of an installation according to the invention. It consists in principle of a receiving basin, generally designated 10, for mixtures of bulk material in pieces, e.g. concrete, and washing liquid for desludging the heaviest pieces of this material, and a conveyor device, generally designate 11, for raising, washing and desludging of the conveyed bulk material.

In the example shown the receiving basin 10 consist of an elongated trough, suitably made of concrete with inclined end walls 12,13 and inclined side walls 14,15, the angles of incline to the horizontal plane preferably being equal to or exceeding the critical angle for slidin against the basin wall for the bulk material 16 to be treated in the installation.

In the case where the wall surfaces of the basin fo a parallellepiped, boundary surfaces 23,24 are formed between the material in dead zones 19,20,21,22 and the material which is in movement towards the conveyor 11. In addition to the material which can be immediately handled in the pipe conveyor, bulk material.16 is collected, which gradually slides down to the conveyor and is lifted up by the same. The buffer consists of the amount of material 16 collected above the boundary surfaces 23,24 and the end walls 12,13. and the side walls 14,15. When the angle of repose of the material is steeper than the angle for sliding against the basin.wall, the material.volumes.25,26 marked with sectional lines are obtained, which can slide along the inclined walls to the intake end of the pipe conveyor. If, however, the basin has a parallellepipedic shape, the volumes 25,26 of bulk material will be part of the dead zones 19,20,21,22. In the latter case, the volumes 25,26 will of course not be a portion of the total buffer capacity of the installation. This gives rise to the paradoxical situation that despite the fact that the basin with the parallellepipedic shape has a greater net volume than the basin with the inclined sides, the latter has a greater buffer capacity or buffer volume than the former. Stationary mounting in bearings of the conveyor device in the basin is undoubtedly too rigid to permit at least limited movement of the receiving end of .the. conveyor for individual adaption to the bulk material in .the basin. This is especially the case if large pieces of the material are wedged between the pipe conveyor arid the basin wall 12 under the same. It is therefore specified according to the invention that the pipe conveyor is to at least a limited degree movable in relation to the normal operating position. As a piece is beginning to be wedged in, the pipe conveyor can remove itself from the wedging location permitting the wedged material to come free. For this reason it is an especially important characteristic of the invention that the conveyor pipe have a cantalevered and movable lower end and that it be surrounded and/or enclosed by means which limit the maximum pivot movement of the pipe both vertically and horizontally.

According to Figs. 1 and 2, the basin 10 has around its edge a barrier or rim 28 which is cast in one piece

/-^-ϋKtΛf/^* with the basin. This barrier is perforated at suitable locations with rinse openings -29 (Fig. 2) in connection with a rinse plate 30. arranged a least along one wall of the basin .and intended to receive, transport vehicles for bulk material, for example .such.as the vehicle designated with the arrow 17 in Fig. 2. This vehicle is designed to be able to be backed against the. barrier 28 which thereby serves as an abutment for the vehicle. The rinse openings 29 are located in such a manner that the rinse liquid use to rinse out its transport vessel 31 can be.led directly on the plate 30 into the basin together with washed out, finer residual particles, which are then recovered in the installation.

The receiving basin 10 also has one or more opening 34 through which liquid and suspended sludge particles can run off into a.concrete gutter or the like 32, defini an upwardly open drain channel 33 for liquid with the suspended sludge particles. The openings 34 thus serve as overflows which determine the upper limit for the level of the liquid 35 in the basin.

For a more detailed explanation of the construction assembly, functioning and interaction of the conveyor device 11 with the basin.10, you are referred in the firs place to Fig. 1, which reveals a conveyor pipe 36 at an incline to the horizontal plane and with its lower end 27 extending down into the basin beneath the liquid level 35 therein. The conveyor pipe 36 is of the type which consis of a long pipe, which has an intake opening 37 at its low end for bulk material which during conveyance upwards inside the pipe is to be subjected to desludging, washing and classification-

Stationary conveyor means in the form of helical flanges 38 (indicated with dashed lines only in the upper portion of the pipe 36) extend on the inner wall of the conveyor pipe 36 along its entire axial link. Through its periphery at the upper end, the pipe 36 has at least one discharge opening.39 for the biggest pieces in the materi handled by the conveyor. The device is designed so that said larger pieces can fall out. through the discharge opening(s) 39 which continually rotate past a separate stationary receiving shoot 40 located beneath the upper end of the pipe 36. The larger pieces 41 which fall out are collected in the shoot 40 and fall through a discharge opening at the lower end of the shoot 40 which is directed towards a storage area 42 for these pieces, which is defined in principle by a bottom, plate 43 and a supporting wall 44.

To support the rotating conveyor pipe 36 a supporting frame (generally designated 46) is stationarily fixed onto a concrete block or the like 45 sunk in the ground. On a shelf portion 47 of the frame, a supporting plate 48 is stationarily fixed (shown most clearly in Fig. 3) for at least two separate roller mountings 49 with supporting rollers rotatably supporting the conveyor pipe 36.

As is shown in Figs. 1 and 3, the conveyor pipe 36 is encircled, at its mid section, by a so-called constraining bar 50, which is fixed with two legs 51 and 52 to the supporting plate 48 or directly on the frame 46, The constraining bar 50 is dimensioned so that, with small play in relation to the legs 51 and 52, it permits a small angular deviation of the pipe conveyor 36 laterally, and has in its upper portion a free space which permits a somewhat larger, although limited-vertical pivoting from the normal working position on the rollers 49 to an abutment formed by the inner surface of the bar cross piece 53 bridging over the pipe 36. With regard to other aspects of the mounting and driving of the conveyor pipe 36, Fig. 4 shows that from the upper end piece 54 of the pipe, a bearing pin 55 extends axially, which is suitably axially hollow to permit the supply of water therethrough to the interior of the conveyor pipe. This bearing pin 55 is mounted in a bearing 56, preferably a spherical bearing, which is mounted in a bearing yoke, beam or the like 57, which is rotatably

^'βύ^'KtΛcT ^■.-.'^■PL. mounted around a horizontal pivot axis by means of two bearing pins 58 in two separate.arms 59 which extend upwards from the frame 46. In the example the bearing pin 55 is the input drive shaft.of the pipe conveyor 36, and it is driven by a motor 60 via a drive gearing (generally designated 61) .

Thus the stationary constraining bar 50 and the preferably spherical bearing 56 are intended to permit at least a limited angular movement of the lower end 27 of the conveyor pipe 36 from and back to its normal working position for engagement with the bulk material in the basin 10, especially in the event that said lower end becomes stuck in the material.

As regards the other structural features of the pipe conveyor 11, the so-called constraining bar 50 is a means which surrounds and/or encloses the conveyor pipe and limits its maximu .pivot movement both vertically and horizontally. In the embodiment shown, the conveyor pipe 36 is also continuously carried and mounted for rotation in a single bearing, namely the preferably spherical bearing 56. This provides the desired flexibility for the lower end 27 of the pipe in relation to the bulk material in the basin, since said end is freely movable and can adjust itself to the level of the bulk material 16 within the limits defined by the constraining bar 50. The intake opening of the pipe can be adapted in each individual case to the characteristics of the material conveyed or treated in the pipe. Preferably immediately next to the actual intake opening 37, there is arranged at least one digging or driving means 63 which keeps the bulk material in motion and at the same times serves as a feed-in means for the same. Said drivers 63 move the bulk .material into the conveyor pipe 36 into engagement with the helical flange or conveyor screw 38 which conveys the bulk material up through the pipe.

In Fig. 1 the lower end 27 of the conveyor pipe 36 is also provided with external dispersing or stirring means. These preferably have such a shape that the bulk material is caused to move towards the intake 37. An especially advantageous embodiment is an external screw conveyor flange 64 (known per se) , which is fixed, to said lower end 27. The screw flange 64 has a direction of pitch which is opposite to that of the interior conveyor flange 38, which means that. the feed directions for the two conveyor flanges will be opposite to each other. The dispersing means 64 works and desludges the bulk material at the same time as it moves it towards the. intake, opening 37.

For a more detailed explanation of the driving arrangement of the pipe conveyor 11, you are referred to Fig. 4, which shows in a partial cut-away view this arrangement in the direction of the arrow B in Fig. 1. Fig. 4 shows the conveyor pipe 36, its end piece 54, the bearing yoke 57 with its two legs 69 and 70. From each leg there extends a bearing pin 58, each of which has a bearing sleeve 71 fitted into the supporting arms 59 of the frame 46, thereby making the yoke 57 pivotable around the essentially horizontal pivot shaft 72, indicated with a dashed line in Fig. 2.

The bearing pin 55 extending out through the end piece 54 is fitted into the inner bearing ring 73 in the bearing 56, the outer bearing ring 74 of which is in turn fitted into the bearing seat 75 in the bearing yoke 57. By virtue of this arrangement, the conveyor pipe 36 is allowed to pivot about its upper end, with the pivot movement being limited by the dimensions of the stationary ' constraining bar 50. 76 in Fig. 4 designates a cover for a gearbox 61

(not shown in detail here) . This gearbox 61 has an output gear 77 which is drivingly connected to the bearing pin 55 on the side of the bearing facing the observer. This means that the gearbox 61 or drive gear mechanism essentially hangs rotatably on the bearing pin 55 via the outgoing gear 77. On a shelf or bracket 78 which is articulated at one point 79 to the casing of the gearbox, a drive motor 60 is

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C..PI attached, which via a number of V-belts from its pulley drives another pulley 81. The latter pulley is fixed to the input shaft 82 of the gearbox. A turnbuckle or bottl screw 83 extends between the shelf 78 and the gearbox casing, by means of which it is possible to adjust the tension in the V-belts by* swinging the shelf 78 to the desired degree. To avoid having the entire gearbox 61 an the drive motor.60 being carried-along by the rotational movement of the conveyor pipe 36, the gearbox is held in place by a connecting bar 84 which is articulated both t the gearbox casing and to a supporting arm 85 securely anchored to one leg 70 of the yoke 57. This arrangement makes it possible to drive the conveyor pipe 36 independ ly of its angular setting and during its pivoting moveme as well.

Fig. 5 shows a modification of the coupling bar 84 in Fig. 4, divided approximately in the middle into two separate stay portions 86a and 86b. These two stay porti are joined to each other by means of an instrument or sensor 87 for sensing tensile stress in the connecting b This sensor can either sense the load over a con¬ tinuous interval or merely sense if the tensile stress exceeds or goes below one or more predetermined values. The sensor 87 is connected via suitable wires 88 to cont means 89 for the movements of the pipe conveyor 11.

A simple form for such means 89 is a stop device which stops the drive motor 60 of the conveyor pipe when the l is excessive, for example when the basin is overfilled. The sensed tensile stress can initiate, via the control means 89, significantly more complicated movements of th end 27.of the conveyor pipe in the basin.10, as describe in- the following.

An example of a device for lifting the lower end 2 of the conveyor pipe 36 from its normal lower working position is shown.in Figs. 6 and 7, with corresponding parts being given the same numerals. This embodiment comprises a constraining bar 98 fixed to the frame 46,

OMP said bar being suitably higher than in the embodiment shown previously.

Rollers 49 are mounted on a movable supporting plate 99, which is articulated at its line of symmetry to a hydraulic piston device 96 which at its other end is articulated to a bracket 97 anchored in the base 45 of the frame 46. This supporting plate 99 has at its two sides two sliding members or supporting roller holders 100, which run. in two guides or rails 101 (with U-profile for example) fixed to the constraining bar 98. With the aid of these guide rails 101 and sliding members 100 the supporting plate 99 and the rollers 49 are fixed both longitudinally and transversely to the conveyor pipe. With the aid of the hydraulic piston 96, the supporting plate 99, and thereby the conveyor pipe 36, can be moved to desired vertical positions between its normal lower working position (shown with solid lines) , and the highest position limited by the beam 102 of the constraining bar 98 (indicated with dash-dot lines and labelled F) . The angular adjustment can be done in steps or continuously. This is advantageous since the rotary movement of the pipe conveyor can continue simultaneously with adjustment within the entire, angular range.

It is obvious that it takes large amountsof energy and involves heavy wear to disperse the bulk material and move it upto and into the intake opening 37 of the conveyor pipe. In the embodiment shown in Figs, 6 and 7, however, when large amounts of material have been collected in the basin, it is possible to adjust the angle of the conveyor pipe 36 so that it only works in a surface layer of the collected bulk material 16, with the major portion of the weight of the conveyor pipe 36 resting on the rollers 49.

To deal with the problems described above in the operation of the pipe conveyor, a control means 89 can be arranged of the type indicated in Fig. 5 in the drawing. Such means can be arranged to monitor and modify various loads on the pipe conveyor for example. For adapting

"B-3KfcA_ operation to varying loads on the pipe conveyor, it can be coupled together with a device for analyzing motor lo The tensile stress in the connecting bar 84 is sensed by the sensor 87 which senses a signal through the wire 88 to the control means 89. When an additional, amount of bulk material 16 is added to the basin 10, the load on the driving machinery will increase..and thus increase the tensile stress in the connecting bar 84. The sensor sends a signal to. the control means 89 arid.when the tensile stress exceeds a certain predetermined value,, the control means 89 sends-an activating impulse to a hydraulic motor system (not shown) which via a hydraulic cylinder 96 rais the lower end 27 of the pipe conveyor by reducing the angular setting relative to the horizontal plane. During this movement the conveyor continues to operate and the sensor 87 senses continuously the load on the conveyor pipe 36 as it rotates. When this load has dropped to an intermediate value, the control means 89 sends an impulse which stops the hydraulic motor and halts the raising of the lower end 27 of the conveyor pipe. The pipe conveyor processes and raises the bulk material while the conveyor pipe 36 is in this raised position, and if no further bul material is- added, the amount thereof will decrease and thus the resistance to the rotation of the conveyor pipe will decrease. This decrease in load is sensed by the sensor 87 and at a lower threshold value, the control mea 89 will send a signal to the hydraulic system, this time lower the lower end 27 of the conveyor pipe 36 by means o the above-mentioned hydraulic cylinder. This lowering is preferably done slowly and is halted when the measured tensile stress reaches an intermediate value, which can b equal to or different from the intermediate value at whic the lifting up of the lower end 27 of the conveyor pipe 3 was initiated. By raising and lowering the lower end 27 of the conveyor pipe it is possible to reduce the power require¬ ments of the conveyor and wear thereon and avoid having the resistance to rotation of the pipe become so strong that it becomes stuck or the emergenc shut-down is triggered.

Furthermore this increases the buffer capacity of the installation significantly, since it is possible to fill the basin 10 with much more material if it is possible to forceably lift the pipe conveyor from its normal, lower operating position. Thus the conveyor buffer capacity will not only be the material collected on the walls 12,13,14 and 15 of the basin (and in.the case where the basin has a parallellepipedic shape, the bulk material collected above the basin bottom beside the conveyor pipe 36 itself, above the dead zones limited.by the boundary surfaces 23, 24, which are determined by the angle of repose) but also by the bulk material collected on the flat bottom of the basin up^' to the uppermost working position of the conveyor pipe. A conveyor installation according to this embodiment, thus has an appreciable buffer capacity for solid material, i.e. the amount of added bulk material 16 beyond the instantaneous capacity of the conveyor and the buffer amounts collected above the walls 12,13,14,15 of the basin and/or above the angles of repose 23,24.

The wash water can be added through a preferably non- rotating rinse water pipe.154, which passes through an opening in a beltguard 155 for the conveyor drive arrange¬ ment and which extends slidably through the hole 156 in the tubular bearing pin 55 in the example. By means of nozzles or jets 157 in the wall of the rinse water pipe 154, rinse or wash water can be sprayed against the interior of the conveyor pipe 36 and against the conveyed bulk material. These nozzles .are of course adjusted to produce the best possible washing effect. A hose 158 is connected to the rinse water pipe 154 for supplying water.

When the conveyor pipe also functions as a classifica- tion apparatus, the installation should.be dimensioned so that the receiving space is given at least a large enough free liquid surface area as to correspond to the desired

QΓ.PI classification separation limit at the mean liquid flow in the installation.according to known formulas.

The invention is not limited to the embodiments shown in the drawings, but can be varied in various ways within the scope of the following claims.

Claims

1. Device for a pipe conveyor for pieced bulk material, said conveyor comprising a rotating conveyor pipe (36) with at least one helical flange (38) fixed to the inner wall of the pipe for moving the bulk material (16) from the intake opening (37) of the pipe to one or more outlet openings (39) for the bulk material, the conveyor pipe being pivotally carried by a transverse shaft (58,69,70,72), its cantalevered intake end (27) being in engagement with and feeding into its interior the pieced bulk material and any finer particles and liquid, c h a r a c t e r i z e d by means (50,98) which surround and/or enclose the conveyor pipe (36) and limit its maximum pivot movements at least horizontally.

2. Device according to Claim 1, characterized in that said means (50,98) limit the maximum pivot movements of the conveyor pipe (36) vertically as well.

3. Device according to Claim 1 or 2, characterized in that the conveyor pipe (36) is continuously carried and mounted for rotation in a single bearing (56) .

4. Device according to Claim 3, characterized in that the conveyor pipe (36) has an axial bearing pin (55) located at its outlet end for the bearing (56) which continuously carries the pipe.

5. Device according to Claim 4, characterized in that the bearing pin (55) is tubular.

6. Device according to Claim 4 or 5, characterized in that a drive arrangement (60,61) for the conveyor pipe (36) is arranged on the. bearing pin (55) .

7. Device according to one or more of the preceding claims, characterized in that the conveyor pipe (36) is mounted (56) so that in. addition to pivot movements in the plane defined by the transverse pivot shaft (72), it can also move, in directions at an angle to said plane.

8. Device according to one or more of the preceding claims, characterized in that the conveyor pipe (36) is rotatable (56) during all of its pivot movements within the limits defined by the means (50,98) enclosing and/or surrounding the pipe.

9. Device according to one or more of the precedin claims, characterized in that the means (50,98) enclosin and/or surrounding the conveyor pipe (36) consist of a stationary, constraining bar, which limits the deviatio of the conveyor pipe from its normal working position.

10. Device according to Claim 9, characterized in that the constraining bar (50,98) is rigidly joined to a frame (46) for the pipe conveyor,

11. Device according to one or more of Claims 3-6, characterized in that the conveyor pipe (36) when idling or at low material load, assumes a normal lower working position, in which the pipe is supported by, in addition to the continuously carrying bearing (56) , support rolle (49) as well mounted between said bearing and the intake opening (37) (Figs. 1 and 4).

12. Device according to Claim 1 or 2, characterized in that the conveyor pipe (36) is pivotally carried and mounted in a bearing (56) for rotation, as well as being provided with means (49,96,97,99,100) for raising and lowering its intake end (27) in relation to the position of the bulk material to be conveyed (Fig. 7) .

13. Device .according to one or more of the precedin claims, characterized by sensing means (87) for the torq of the conveyor pipe (36) and/or a variable dependent thereon, which means send a signal.to a control system (8 for the pipe conveyor (Fig. 5) .

14. Device according to Claims 12 and 13, characteri in that the control system (89) controls. the raising and lowering of the lower end (27) of the conveyor pipe depending on the sensed torque or the variable dependent thereon (Figs. 5, 6 and 7) .

15. Device according to one or more of the preceding claims, characterized in that it has a frame (46) which i pivotable about a horizontal pivot axis and is provided with a lifting device for pivoting the pipe conveyor (11) in its entirety.

16. Device according, to Claims 13 and 15, characterized in that the control system (89) . controls the pivoting of the pipe conveyor (11) in its entirety in response to the sensed torque or the variable dependent thereon.