METHOD OF AND PLANT FOR MATERIAL DISTRIBUTION

Abstract: A method of material distribution for distributing free-­ flowing material is provided which consists of transporting the material in bulk from one location to another, siting a mobile bagging apparatus at the second location, unload­ ing the transported material into the bagging apparatus, and bagging the material for use. In a preferred arrange­ ment the mobile bagging apparatus has a receiving hopper for material, a weighing and bagging machine for metering the material into bags in predetermined quantities by weight, and a stitching machine for closing the bags. The material is suitably transported in bulk by transport ship.

Description: This invention relates to an improved method of material distribution and to bagging plant for use in the method. At present, when free-flowing materials such as fertiliser and grain are transported overseas, the material is first bagged into predetermined bag sizes and then transported. This has two main disadvantages: (i) the bags are not completely complementary in shape so that more space is occupied than if the material were transported in bulk; and (ii) the bags are susceptible to damage and therefore there are limits on loading so as to prevent the bags splitting. However, with present distribution methods there are really no alternatives which will provide the material producers with the product guarantees they require. By bagging the material before distribution the producers have complete control over the product and any damage to the material will only be sustained through mishandling. Thus, before distribution, the producers meter free-flowing material into bags, usually measured by volume, and then seal the bags by heat sealing and/or stitching ready for transportation. In French Application No. 2398666 there is disclosed a bagging apparatus in which material is packaged in bags by weight. The bagging apparatus is mounted on a traiter so that it may be moved about by road. However, such apparatus is not suitable for transport from port to port by sea. An object of the present invention is to provide an improved method of material distribution which enables material to be transported in bulk and to provide bagging plant for use in the method. According to the present invention this object is achieved by the method of claim 1 and the bagging plant of claims 2 and 3. The present invention has the particular advantage that, by housing the bagging apparatus in a transportable module of standard container dimensions the bagging units are readily transported by existing road, rail and sea methods. The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a perspective view of a bagging plant comprising a plurality of a first embodiment of bagging unit in use in accordance with the invention; Figure 2 is a perspective view from above of a bagging unit shown in Figure 1 and showing its separate power pack module; Figure 3 is a sectional, partially diagrammatic, end elevation of a bagging unit (without the separate power pack module) on 3-3 in Figure 4. Figure 3A is a detailed drawing of the weighing and bagging machine shown in Figure 3; Figure 4 is a sectional side elevation of the bagging unit shown in Figure 3 on 4-4 in Figure 3; Figure 5 is a diagrammatic plan view on 5-5 in Figure 6 showing an alternative bagging unit; Figure 6 is a diagrammatic view on arrow A in Figure 5; and Figure 7 illustrates an example of a heat sealing machine that may be used with the bagging unit of the present invention. In Figure 1 of the drawings a mobile bagging plant 1, for bagging free-flowing material such as fertilisers, is shown located on a port quay 2. The bagging plant 1 illustrated comprises three bagging units 3 each of which is positioned for receiving free-flowing material from a docked transport vessel 4. The material is moved from the docked vessel 4 to the bagging plant 1 by means of a mechanical grab 5 having two scoops 6 pivoted at 7 and arranged so that they may be opened and closed by means of mechanical levers as desired. The scoops 6 have covered tops so as to deter spillage - the grab may be known construction and therefore, further details are not provided. A bagging unit 3 of the first embodiment (see Figures 2, 3, 3A and 4) comprises four transportable modules 8 of standard transportable container dimensions and a power pack module 66. The four modules 8 are strengthened along their edges for transport and may be locked together in the arrangement shown; namely two upper modules and two lower modules, by suitable fastening means,(not shown). The upper modules 8 have an open top 9 which is covered by grating 10 and includes a plurality of roof bow members 11. The roof bow members 11 provide support for a removable tarpaulin or like material roof covering 12 (Figure 2). The inside of the upper modules 8 include a sloping partition 13 defining a hopper inclined downwardly towards a substantially centrally disposed outlet 14. The lower modules 8 of the bagging unit 3 each have an openable pair of end doors 15 and an access door 16 formed in the side wall. The lower modules 8 each retain a bagging and weighing machine 17 which is positioned below the outlet 14 from the respective upper module. The bagging and weighing machine 17 is shown in detail in Figures 3, 3A and 4 and comprises a standard weighing unit 18 of known construction mounted on a wall of one of the lower modules 8 and a weighing hopper 19. The machine has been modified to provide a unique design to ensure accuracy whilst avoiding spillage and jamming and those features which depart from conventional design have been shown in detail whereas the known features, which form no part of the present invention, have been omitted for clarity. The standard weighing unit 18 includes a graduated scale 20 and a weighing support frame 21 on which the weighing hopper 19 is carried. The weighing hopper 19 is positioned below the outlet 14 but is free to move downwardly relative thereto on filling. It comprises an upper inlet 22, a transparent polycarbonate side wall 23, and a bottom wall 24 tapering towards a lower outlet 25. The outlet 14 is normally closed by a valve means 26 including, shown diagrammatically, a first valve 27 to control free flow of material and a second valve 28 cooperating with a restricted opening defined by the first valve 27 for trickle flow for final weight adjustment. The lower outlet 25 consists of two flap valves 29 which close against a central member 30 and which are pivoted to the weighing hopper 19 beneath a depending extension 31 of the bottom wall 24. The position of the pivot points protects them against becoming jammed in use. The movement of the valves 27, 28 and 29 is effected by respective double-acting, hydraulic cylinders 32; only those for flap valves 29 being shown. Suspended below the valved lower oulet 25 is a filling chute 33 having bag support clamps 34 pivotally mounted thereto as shown which are movable by means of double-acting hydraulic cylinders 35. The filling chute 33 is supported by means of a frame 36 extending downwardly from about the outlet 14 and which surrounds the weighing hopper 19. Reverting to the weighing unit 18 it will be seen that this is provided with three controlling limit switches 37, 38 and 39 (Figure 4). Switch 39 is at zero and is effective to ensure closure of the flap valves 29 as shown to the left in Figure 3A and release of the bag clamps 34 is also as shown to the left in Figure 3A. In this position the weighing machine may only be operated by a user clamping a bag on the filling chute 33 and actuation of a safety operation switch (not shown). This will then cause valves 27 and 28 to open so that material flows through outlet 14 into the weighing hopper 19 until the weight reaches limit switch 37. This switch causes closure of the valve 27 to reduce material flow as it approaches the desired weight. When switch 38 is tripped the valve 28 is closed stopping material flow completely and providing an accurate measured load whereupon the flap valves 29 are released to fill the bag clamped below. In addition to the bagging and weighing machine 17 the lower modules 8 also each include a slatted endless conveyor 40 disposed beneath the machine and provided with lateral guides 41 so that, when filled, a bag 42 may be passed to a stitching station 43. The stitching station 43 includes a proprietary stitcher, suitably a DOBOY (Registered Trade Mark), which is activated automatically as each bag is fed into the machine. If desired, for example in damp environments a heat sealing station may be provided between the bagging station and the stitching station. A preferred heat sealer illustrated by way of example in Figure 7 is a proprietary heat sealer marketed by The Thames Packaging Equipment Company under the trade mark SAXON. The sealer 44 receives the mouth of the bag 42 as it passes along conveyor 40 sealing the mouth of the bag by the application of heat. The heat sealer 44 suitably may be height adjustable on a vertical pillar 45 by means of turn wheel 46. Although a SAXON heat sealer and a DOBOY stitcher have been shown as an example it will be understood that any form of suitably heat sealing and stitching assembly may be used. Outside of the modules 8 it will be seen that the endless conveyors 40 feed the bags 42 to respective conveyor elevators 54. The elevators 54 have a first section 55 receiving bags 42 from the conveyors 40 and a second section 56 feeding the bags onto the transit vehicle 57. The first section 55 is preferably a plain conveyor although a slatted conveyor is illustrated in Figures 1 and 2: the second section 56 may be slatted or plain. In order to provide continuity of the process the second section 56 is angularly adjustable about two perpendicular axes so that it may vary its upwardly inclined attitude and slew from side to side, for example during the transition from loading one vehicle to loading another. It will be seen from the above that each bagging unit includes constituent parts in duplicate. The reason for this is that the modules 8 are narrow in width and therefore, if two modules were not locked together, there would be a danger of free-flowing material spilling over the sides of a single module during supply of material to the bagging unit. Moreover there are preferably three units as shown in Figure 1 to provide for fast bagging. In Figures 5 and 6 an alternative embodiment is illustrated diagrammatically. In this second embodiment the bagging plant 60 comprises a single module 61 having parallel bagging runs 62 along each side. Each run consists of a weighing and bagging station 63 and a stitch station 64 with a sealing station therebetween if desired. The detail of the weighing and bagging machine and the stitching machine may be as shown and described in respect of the first embodiment. In addition the single module includes side access doors 65 for each run 62 and a power pack module 66 accessible by means of openable end doors 67. So that the bagging runs 62 may be operated independently of one another each run extends to an individual openable end door 68. As explained above, with a single module width, there is a danger of material spilling over the sides. In this second embodiment the material hopper is provided by side walls 69 which are hinged to the top of the module 61 and are movable to a position indicated by dotted lines 70 by means of hydraulic cylinders (not shown). In order to close the gaps between adjacent side walls 69 each side wall is provided with a hinged flap which overlaps the adjacent side wall and is held against the said side wall by the pressure of the material within the hopper. The grating of the first embodiment suitably is replaced by a nylon mesh indicated by dotted line 71 and a tarpaulin may be provided if desired. In use, in either embodiment, a contract is obtained and then, rather than shipping material already bagged, the material is loaded in bulk into a bulk transport vessel for transportation to the nearest, or most convenient port, for the required destination. The advantage of bulk transit is that much more material can be handled since, with material that has already been bagged, more space is occupied and there are restrictions on loading in order to prevent bag breakage. At the same time a mobile bagging plant in accordance with the invention is transported to the port in question for assembly on the quay just prior to the arrival of the transportation vessel. The bulk material is then unloaded from the vessel by means of one or more grabs 5 which deposit the free-flowing material into the receiving hoppers of the bagging units: in the first embodiment the grab may be provided in the power pack module 66. The material flows from the receiving hopper, through respective valve controlled outlets 14, to the bagging and weighing machines 17. Once the weighing hopper is full, the valved outlet 14 is closed, the flap valves 29 opened to fill the bag, the full bag passed for stitching and heat sealing if necessary and then a new bag suspended for filling. The full bags are then loaded onto waiting vehicles for transportation to their final destination at a rate of about six bags per minute; approximately the same rate as it would take to unload ready bagged material. If the weather turns bad during unloading the hatches on the transportation vessel would be closed and tarpaulins placed over the material loading hopper. Bagging is then continued until the supply of free-flowing material retained in the hopper is exhausted. The bagging units of the present invention are provided with their own generators so that the units are totally self-sufficient these may either be separate units or part of the same unit. Once unloading and bagging of the material has been completed the mobile bagging units are moved from the quay, in the case of the first embodiment disassembled and, if necessary, moved to another port where they are required. The standard container size of the modules of the bagging units means that the bagging units are readily transported by existing road, rail and sea methods.

Claims: A method of material distribution for distributing free-flowing material comprising the steps of transporting the material in bulk in the hold of a transport ship from a remote location to a port quay, siting a bagging plant having a receiving hopper and a bagging apparatus provided with weighing means at the port quay, delivering the material from said bulk supply to the receiving hopper, metering the material from the receiving hopper to the weighing means determining the quantity of free flowing material for a bag by weight, delivering the weighed quantity of material into the bag and bagging the material ready for use, characterized by the steps of housing the bagging apparatus in a single transportable module of standard container dimensions, delivering the material directly from said bulk supply to the receiving hopper by means of a grab, and, after completion of bagging, transporting the bagging plant to another port where it is required. A bagging plant (1;60) for use in the method of claim 1, the plant comprising means for defining a receiving hopper (13;69) for receipt of the free flowing material and a bagging apparatus having weighing means (17;63); means (26) for metering the free flowing material from the receiving hopper to the weighing means (17;63) in order to deliver a pre-determined weight of free flowing material into a bag, and means (43;64) for closing the bags, characterized in that the bagging apparatus is housed in a first transportable module (8;61) of standard container dimensions and the means defining a receiving hopper is provided in a second transportable module of standard container dimensions which, in use, is positioned above and interlocks with the first transportable module, whereby the bagging plant is readily movable from one bagging site to another A bagging plant (1;60) for use in the method of claim 1, the plant comprising means for defining a receiving hopper (13;69) for receipt of the free flowing material and a bagging apparatus having weighing means (17;63), means (26) for metering the free flowing material from the receiving hopper to the weighing means (17;63) in order to deliver a pre-determined weight of free flowing material into a bag, and means (43;64) for closing the bags, characterized in that the bagging apparatus is housed in a single transportable module (8;61) of standard container dimensions and the means defining a receiving hopper comprises a plurality of flaps hingedly connected to the top of the transportable module which may be extended so as to define the receiving hopper whereby the bagging plant is readily movable from one bagging site to another. A bagging plant according to claims 2 or 3 characterized by weighing means (17;63) comprising a weighing hopper (19), means (26) for metering the free flowing material to the weighing hopper (19) comprising first valve means (26) for the control of flow of material into said weighing hopper (19), second valve means (25) for the control of the delivery of a weighed quantity of material into a bag, and bag retention means (34). A bagging plant according to claim 4 characterized in that the first valve means (26) comprises, a first valve (27) for controlling free flow of material into the weighing hopper (19), and a second valve (28) for restricting the free flow to a trickle flow as the weighing hopper (19) approaches the desired weight. A bagging plant according to claim 4 or 5 characterized in that the second valve means (25) comprises at least one pivotal valve (29), the pivotal point of which is protected against contamination by said material thereby protecting against jamming. A bagging plant according to any of claims 2 to 6 characterized in that the means for closing the filled bags is a stitching machine (43;64). A bagging plant according to claim 3 characterized in that the plant comprises two parallel bagging runs with respective conveyors (40;62) extending between a weighing and bagging station (17;63) and a stitching station (43;64). A bagging plant according to claim 3 including two parallel bagging runs each including metering and weighing means (26;17;63) arranged to receive a controlled quantity of material from the hopper, stitching means (43;64) for closing the filled bags, and a conveyor (40;62) for moving the filled bags from the metering and the weighing means (26;17;63) to the stitching means (43;64) the metering means (26) comprising a valved outlet (26) between the receiving hopper and the weighing means (17;63).

Inventors: NEDERPEL, GERARDUS LEONARDUS, VAN DER WAL, JAN
Applicants: NAT SHIPPING BAGGING SERVICES, NAT SHIPPING BAGGING SERVICES LIMITED
Application year: 1982
Main classification: B65B1
IPC codes: B65B1, B65G63