A device for handling of bulk material

Abstract: When handling bulk material a pressure vessel (10) including at least two members (11, 12) and provided with equipment for mechanically enclosing a portion of the bulk material is used. By means of pressure fluid from a conduit (17, 18) connected to the pressure vessel, a pneumatic evacuation of the enclosed material occurs by way of discharge conduit (20).

Description: Bulk material can be of different kinds, and the loading and unloading thereof raises many problems. Some materials such as cement and powdered coal are dust emitting, and other types of material will issue odours. Mechanical as well as pneumatic conveyors have been proposed, and also combination of such means. When it is actual to handle big volumes of material at a certain place, it is possible to errect a permanent plant with high efficiency. FR-A-2 361 286 discloses such a permanent, stationary device for the handling of bulk material having a large, fixed pressure vessel for enclosing a volume of bulk material and a conduit connected to the pressure vessel for supplying a pressurized gas thereto for carrying of the enclosed material by way of a discharge conduit. Moreover a permeable, grid-like bottom is provided, where the conduit for the supply of pressurized gas opens into the space below said bottom (se particularly the Figs. 1, 2, 4 and 5 in the document). When smaller quantities are involved, which are collected or delivered at different places or where perhaps some time will pass between each occasion of use, no proper device has been available, which at reasonable errecting costs has been able to perform the necessary handling service. A common field of use is marine transportation, where a ship may have to deliver part of its cargo at different ports, which lack proper handling devices, or a factory or plant, which is served with occasional ships, which lack unloading means, but have to deliver some bulk material. The aims of the present invention is to propose a handling device, which is cheap to manufacture, which is easily mobile, and which in an advantageous manner can handle dust material. For pneumatic transportation it is advantageous to enclose the material in a pressure vessel, from which it may be blown out. Several ways of filling the pressure vessel as a first step in the handling have been proposed, but have not worked satisfactorily According to the present invention the pressure vessel is designed as a grab, which itself will collect a quantity of material, suitable for the next step of transportation. The device comprises a pressure vessel with at least two members for mechanically enclosing a volume of bulk material, and a conduit connected to the pressure vessel for supplying a pressurized gas thereto for carrying of the enclosed material by way of a discharge conduit. The invention is especially characterized by that the members are provided with means for moving them between open and an closed position for grabbing an amount of bulk material. At least one of the members of the pressure vessel is then provided with a permeable, gridlike bottom and a conduit for the supply of pressurized gas opens below said bottom. The pressure vessel preferably comprises two substantially similar halves which are pivotably carried in a yoke and connected to pressure fluid actuators for swinging the halves in relation to the yoke. In order to facilitate an emptying, each pressure vessel half is advantageouly provided with a pervious bottom structure extending downwardly form the end plate of the half to the plane of division between the halves, and the discharge conduit includes an internal extension extending to the plate of division, adjacent to the meeting bottom structures. The yoke may be connectable to a lifting device for instance a crane in a harbour or upon a vehicle. The yoke may be carried in the lifting device by way of a sliding member, which is actuated so the point of attachment can be moved past the vertical center line of the unit. The pressure vessel will then be tilted which facilitates the enclosed matter sliding towards one end of the pressure vessel. The discharge conduit will then have an internal extension opening at the lower end of the pressure vessel. The yoke with the pressure vessel may hang in a travelling crane movable along the coamings of a cargo hatch opening in a ship. The pressure vessel may alternatively comprise a grab member and a lid adapted to close the same, and be mounted upon a wheeled vehicle for instance a front loader. The pneumatic transportation part preferably includes a supply conduit with at least one branch opening inside the pressure vessel, one branch to a booster in the discharge conduit, and a valve for determining the fluid distribution between the two branches. The invention will below be described with reference to the accompanying drawings, in which: Fig. 1 schematically shows a device according to a first embodiment of the invention, Fig. 2 on a larger scale shows a pressure vessel forming part of the invention. Fig. 3 shows a further embodiment according to the invention, Fig. 4 shows the device according to Fig. 3 in tilted position, ready for unloading, Fig. 5 shows the device mounted on a travelling crane onboard a ship, and Fig. 6 shows a further embodiment according to the invention, mounted upon a truck. Fig. 1 very schematically shows the pressure vessel 10 with connected conduits. The vessel comprises, as is better evident from Fig. 2, two substantially similar members 11 and 12, which are pivotably carried by a yoke, not shown in the drawing and may be swung away from each other and then towards each other for grabbing an amount of bulk material, for instance in the cargo hold of a ship. The enclosed bulk material is then blown off pneumatically. It is presupposed that the two members will sealingly engage each other. Each member comprises a cylindrical shell part 13, and a domed end plate 14. Each member 11, 12 is provided with an inclined, pervious bottom structure 16, which extends from the end plate 14 to the plane of division 15 between the two members. Depending upon the kind of material to be handled, the bottom structure may consist of a gridlike device, or contain parallel rods covered by a wire mesh or fabric. Compressed air for the pneumatic transportation is supplied by way of a conduit 17, which is divided into two branches 18 and 19. The first mentioned one, 18, is further branched into conduits 18a and 18b, which open below the bottom structures 16, and in the first hand will cause a fluidization of the material whereupon the air will also force the material out by way of the discharge conduit 20. This extends within the pressure vessel 10, to the plane of division 15, down into the angle formed between the meeting bottom structures 16, so a major part of the enclosed material will be removed during each cycle. The branch conduit 19 is connected to an ejector 21, which acts as a booster, aiding in forcing the material through the discharge conduit 20. The compressed air system advantageouly comprises an adjustable valve 22 for determining the fluid distribution between the two branch conduits 18 and 19. Depending upon the kind of material to be handled and the actual length of the discharge conduit, a bigger portion of the compressed air may be alotted to the pressure vessel 10, or to the booster 21, respectively. There are remotely controlled valves 23 and 24, respectively, adapted to open and close conduits 18 and 19, and in the first mentioned conduit a safety valve 25 is provided. Blow-off of remaining pressure at the end of a working cycle is governed by a valve 26. Also in the discharge conduit 20 there is a remotely controlled valve 27. Monitoring of the valves occurs in step with the working cycle and belongs to well known technique, and no detailed description is deemed necessary. It is evident that air should not flow through the vessel when this is open to collect material, and there are sensors indicating where the vessel members 11 and 12 have engaged each other sealingly, so a supply of compressed air can force the enclosed material out through the discharge conduit 20. Reference 28 denotes a control box which receives signals from an operator's post by way of a leader 29 and governs the valves. The members of the pressure vessel are preferably hydraulically operated, and the box 28 may house an electric motor and a hydraulic pump. On such occasion a conduit for the supply of electric current may run parallel with the leader 29. Fig. 2 shows in full lines members 11 and 12 brought to engaging position for forming a pressure vessel. Suitable packings are provided at the plane of division 15, and during the pneumatic transportation step the members are clamped together by means of remotely controlled locking devices 30. The members are pivotably carried in a yoke 31, which preferably is designed as a box structure in which valves and operating equipment may be enclosed. The yoke hangs in a wire 32 from a crane or the like, so it can easily be brought into a desired position. The conduit 17 for the supply of compressed air, the signal leader 29 and the parallel electric current conduit are connected to the yoke. Reference 26a denotes a cover for the safety valve 26. The members 11 and 12 are pivotable about trunnions 33 and 34, and may be swung to the position indicated in broken lines by means of hydraulic rams 35. When the vessel, opened to this position, is lowered into a mound of bulk material, and is then lifted while simultaneouly closing the members, the vessel will bring along a certain portion of the material in the same manner as a common grab escavator. The design and the equipment at the members will ensure that the members in a following step act as a pressure vessel. This of course presupposes that thickness and quality of the plates in the shell 13 and in the end plate 14 will withstand the actual air pressure. Fig:s 3 and 4 show a further embodiment according to the invention, adapted to be tilted during the unloading operation. Whenever possible, the same reference numerals as in Fig. 1 and 2 are used. The two pressure vessel halves 11 and 12 are pivotely supported in a yoke 31. Compressed air is supplied by a conduit 17 and is subdivided into two branches 18a, 18b for fluidizing and pressurising purposes. Branch conduit 18a is further branched off to a booster 21 in the discharge conduit 20. The novel feature here is that the yoke 31 is provided with a bar 40, which during loading operation is horizontal, and has sufficient extension to permit a sliding device 41 connected to the lifting line 32 to be located in the vertical center line of the unit. A pressure fluid ram 42, controlled in any suitable manner in step with the other actuable govering devices, will push the sliding device 41 to the right in the drawing, when the two members 11 and 12 have been closed and satisfactorily locked. The device will then take up the position shown in Fig. 4, where the sliding device 41 is moved well past the vertical center line, and the pressure vessel tilts with the end where the discharge conduit is attached lowermost. This facilitates the sliding of the enclosed material towards the lower end. The pervious bottom structures 16a are formed like bowls, a short distance inside the shell of the pressure vessel. The extension 43 of the discharge conduit 20 opens just inside the pressure vessel, as the material will slide down towards this end. A handling device of the kind described above can be mounted permanently in a harbour, but can easily be transported between various places of use, for instance by means of a crane mounted opon a truck. A common location will be aboard a ship, where it can be handled by means of existing jibs or cranes. In special bulk transportation ships the equipment can be carried by a travelling crane running along the longitudinal sides of the hatch opening. Fig. 5 shows an arrangement where a complete unit 45 with yoke, swingable pressure vessel halves and the necesary moving equipment is hung below a travelling carriage 46 in a portal crane 47, movable along the coamings 48 enclosing a hatch opening 49 in a ship. The necessary air compressors are mounted on the carriage 46 and supplies compressed air by way of conduit 17 to the unit 45. The discharge conduit, which may be supported in any suitable way, is also here denoted by 20. As shown in Fig. 6 a simple transportable unit may consist of a single member 11 and a lid 50 for closing the opening thereof located corresponding to the plane of division 15 in Fig. 2. The vessel is mounted upon a vehicle 51 of the front loader type, which with the lid open collects material from a mound 52. When the vehicle has backed away and the lid 50 has closed the vessel, this is ready for the pneumatic transportation step. The necessary compressor 53 is mounted upon the vehicle, and supplies compressed air by way of conduit 17. A box 54 containing the necessary valving and hydraulic equipment is mounted upon member 11. The lid 50 may be pivoted by means of a power hinge 55, which is supported with pressure fluid by way of a conduit 56. The devices described above and shown in the drawings are examples of the invention only, and the details thereof may be varied in many ways within the scope of the appended claims. As bulk material is in the fist hand solid granules or dustlike substances considered, but the device may also be used for the handling of liquid or wet substances. When dredging the apparatus may remain submerged, opening and closing below water level, and the silt being ejected pneumatically.

Claims: A device for the handling of bulk material comprising a pressure vessel with at least two members (11, 12) for mechanically enclosing a volume of bulk material, and a conduit (17, 18) connected to the pressure vessel for supplying a pressurized gas thereto for carrying off the enclosed material by way of a discharge conduit (20) CHARACTERIZED BY that the members (11, 12) are provided with means (35) for moving them between an open and a closed position, for grabbing an amount of bulk material. A device according to claim 1, CHARACTERIZED BY that at least one of the members of the pressure vessel is provided with a permeable, gridlike bottom (16), and that a conduit (18a, 18b) for the supply of pressurized gas opens below said bottom. A device according to either of claims 1 or 2, CHARACTERIZED BY, that the pressure vessel (10) comprises two substantially similar halves (11, 12), which are pivotably carried in a yoke (31), and connected to pressure fluid actuators (35) for swinging the halves in relation to the yoke. A device according to claim 3, CHARACTERIZED BY, that each pressure vessel half is provided with a pervious bottom structure (16) extending downwardly from the end plate of the half to the plane of division between the halves, and that the discharge conduit (20) includes an internal extension, extending to the plane of division, adjacent to the meeting bottom structures (16). A device according to either of claims 3 or 4, CHARACTERIZED BY, that the yoke (32) is connectable to a lifting device (32). A device according to claim 5, CHARACTERIZED BY, that the yoke (31) is carried in the lifting device (32) by way of a sliding member (41) actuable by a means (42) for transferring the point of attachment past the vertical center line. A device according to claim 6, CHARACTERIZED BY, the discharge conduit (20) including an internal extension (43) opening adjacent to the end of the member (11) remote from the point of attachment. A device according to claim 5 for use onboard a ship, CHARACTERIZED BY, the yoke (32) being connectable to a travelling crane movable along the coamings of a cargo opening. A device according to either of claims 1 or 2, CHARACTERIZED BY, that the pressure vessel comprises a scoop member and a lid therefor, mounted upon a wheeled carriage. A device according to either of the preceeding claims, CHARACTERIZED BY, that the pneumatic transport system includes a supply conduit (17) having at least one branch (18) opening inside the pressure vessel (10), one branch (19) connected to a booster (21) in the discharge conduit (20), and valve means (21) for determining the fluid distribution between the branches (18, 19).

Inventors: MANSSON TORE, MANSSON, TORE
Applicants: INDUSTOR AB
Application year: 1990
Main classification: B65G53
IPC codes: B65G53, B65D88, B63B27, B66C3