Field of the invention

The present invention relates to an unloading system for bulk material, especially for unloading bulk material from a hold in a transportation vessel, comprising a vertical con¬ veyor and a scraper device adapted to pass the bulk material in a direction towards the unloading input end of the verti¬ cal conveyor.

Prior art

In connection with the unloading of bulk material from a ship, there are often used land based unloading devices, for example a conveyor suspended by a crane beam, and which can be referred to as a vertical conveyor, and which is intended to convey bulk material from the hold. Such vertical con- veyors can by means of the land based crane device be dis¬ placed to the various areas of the hold for removing the main portion of the bulk material. Such land based unloading devices are however relatively expensive and are rearly present in all harbours where unloading of bulk material is desired.

Another solution in connection with the unloading of the hold of a transportation vessel is therefore related to the installation of permanent unloading devices in the vessel itself. Such unloading devices which are mounted in the hold itself are usually very complicated and often encumbered by the disadvantages that they can not be used for a complete removal of all bulk material. This is especially the case in connection with the unloading of bulk material comprising soya derivatives, cement or aluminum oxide.

From SE patent publication 419 737 there is known a device for unloading bulk material from a hold, there being used a

vertical conveyor having its infeed end directed towards the bottom of the hold, there being in connection with the vertical conveyor provided a scraper device adapted to pass bulk material in the direction towards the infeed end of the vertical conveyor. The scraper device is arranged tele- scopically extendable and is pivotably supported at the bottom thereof, and is at the same time pivotably arranged on a protecting pipe provided around said vertical conveyor.

This _t prior art device renders an effective emptying of the hold of a ship, but the protecting pipe is pivotably connec¬ ted with the hatches of the hold, such that the prior art unloading device provides a system which is accurately adapted to the hold structure given by the ship design.

From GB 1 567 877 there is known a device for unloading transportation vessels, there being here used at least one blade Wheel for the transport of material from the hold, the cross section of said hold corresponding substantially to the cross profile of the apparatus carrying said blade wheel. JUso in this case it is a token about a device which is especially adapted to the hold to be emptied, which means that the system has limited application possibilities.

According to GB 1 528 088 there is known an apparatus for emptying bulk material from a storage compartment, said apparatus comprising a main rake passing the bulk material in the longitudinal direction of said storage compartment, as well as a transversely arranged rake, and a -vertical conveyor device. The main rake is provided with a digging arm which is movably and pivotably arranged on the rake. By means of the digging arm the bulk material may be digged out between the various rake arms for transport of the digged out material by means of said rakes.

Objects of the invention

The object o ^* E the present invention is to provided a simple

and effective unloading system, which results in that the unloading vessels to which the unloading system is to be adapted, can be used not only for the transportation of bulk material, for example gypsum or similar downstream material, but also for transportation of usual piece goods or similar.

In other words there is aimed for providing an unloading system to the fact that the vessel does not need to be a special ship which has especially adapted hold bulkhead walls or bottoms, or comprises especially adapted unloading devices which renders difficult the use of the vessel for anything else than bulk material.

This will result in that the vessel having the unloading system according to the present invention installed, can be used for transportation of for example gypsum or similar to one destination, whereafter the vessel can be loaded with piece goods or similar from the unloading place or from another harbour, because the hold is then adapted to convey both bulk material and piece goods.

Disclosure of the present invention

In connection with an unloading system of the type as stated in the preamble, the above stated problems are solved in that said unloading system is characterized by comprising in combination a conveyor device provided in the area of a hold bulkhead wall and communicating with said vert-ical conveyor, and a scraper device provided in the subject hold and being adapted to sweep across the hold and to communicate with said conveyor device.

More specifically the invention defines the conveyor device to take the form of a screw conveyor which is provided close to the hold bottom and preferably along a recess in the hold bulkhead wall, and most appropriately there is in connection

4 with a plurality of bulkhead walls in the vessel provided one screw conveyor for each bulkhead wall.

In other words there will between each hold be mounted a screw at the ship bottom, and this screw will feed the bulk material to for example a bucket elevator lifting the bulk material above deck. The elevator may in turn pass the bulk material to a common conveyor band which in turn feeds the masses to a pivotable band which provides for unloading for example more than 20 m from the side of the ship.

The scraper device may appropriately be mounted on a carri¬ age which is mounted on the bulkhead wall of the subject hold, and which can be displaced along rails provided on the bulkhead wall, and which also serve for the reinforce¬ ment of the bulkhead wall or the bulkhead walls.

In order to sweep across the bottom of the hold the scraper device may take the form of a chain conveyor including catches, and the one end of said scraper device can then be provided at the lower area of a raiseable and lowerable substantially vertically arranged rod on said carriage, said rod also being pivotable about its substantially vertical axis. At the front portion the scraper device may be attached to ropes, for example ropes v ich can have their lejigth varied from deck level, for example by means of appropriate winches, which in turn may be remotely control¬ led.

Preferably there may be provided two scraper devices in the intermediate holds, whereas in the front and aft hold there may be provided an individual scraper device.

Consequently, one or more of the scraper devices may sweep across the overall bottom of the boat, and the angle of the individual, scraper device may be adjusted in dependence of the downstream angle of the loose masses, at the same time as the chain conveyor of the scraper cevice including

catches can have its transportation direction reversed for pulling out loose masses from the corners existing beyond the receiving area of the screw conveyor.

By this form of unloading system the unloading work may be carried out and inspected at deck level, where the operator has a full survey of the hold through the upper hatch opening of the hold.

In the following the invention will be further described with reference to the drawings relating to an example of an embodiment of the invention.

Brief discussion of the drawings

Fig. 1 is a perspective view as seen obliquely from above, of a vessel wherein certain elements have been cut off, and illustrates an embodiment of the unloading system according to the present invention.

Fig. 2 is a cross section through the vessel taken in the vicinity of a bulkhead wall.

Fig. 3 is a cutting out of a vertical section through a bulkhead wall.

Fig. 4 is a simplified view of principle illustrating how an embodiment of the system according to the invention may operate in praxis.

Fig. 5 illustrates a detail in the elongated unloading device which is pivotably arranged about a horizontal axis and a vertical axis.

Description of embodiments

In Fig. 1 there is in a simplified manner illustrate a per¬ spective view of a bulk vessel which is generally designated

by the reference numeral 1 , and which comprises one or more holds 2a, 2b, 2c and 2d, respectively, which can be used for transportation of bulk material, for example gypsum or similar downstream material, but which can also be used for usual piece goods. In other words it is here a token about a bulk vessel 1 which originally has been built for usual piece goods, i.e. without any especially adapted holds, but which at an appropriate stage may be rebuilt to comprise the unloading system provided by the present invention.

In Fig. 1 as well as in the remaining Figures, there is thus illustrated an embodiment of an unloading system comprising elements which are adapted for self-unloading of loose masses in a bulk ship, and which is mounted permanently in the ship, but which have such a structure that they may be pulled out towards the sides of the ship for thereby giving space for holding usual piece goods.

Said holds 2a-2d are divided by means of bulkhead walls 3a- 3e, and in the area of at least one bulkhead wall of each hold there is provided a vertical conveyor. In the present example of an embodiment there are provided three vertical conveyors, 4a, 4b and 4c, respectively, and all of these co¬ operate with at least one scraper device, 5a, 5b, 5c, 5d, 5e and 5f, respectively, provided in each hold. It is to be understood that appropriately there may be provided two scraper devices in the intermediate holds 2b and 2c, whereas in the front hold 2a and the aft hold 2d there may be provided an individual scraper device, see especially Fig. 4.

The system according to the present invention also comprises a conveyor device provided in the area of one hold bulkhead wall, here the bulkhead walls 3b, 3c and 3d, for example a screw conveyor 6a, 6b, 6c which communicate with a respec¬ tive said vertical conveyor 4a, 4b and 4c, respectively.

Each of the scraper devices 5a-5f in the holds 2a-2d is

adapted to sweep across the hold 'for thereby communicating with one or more screw conveyors being present in the sub¬ ject hold.

Each screw conveyor 6a-6c is provided in the vicinity of the hold bottom 7 and preferably along a recess 8a, 8b and 8c, respectively, in the subject hold bulkhead wall 3b, 3c and 3d, and in case of several bulkhead walls there is pro¬ vided at least one screw conveyor for each hold.

In an appropriate embodiment each screw conveyor 6a-6c is provided in a recess 9a-9c in the bottom 7 of the transpor¬ tation vessel, each of the recesses 9a-9c having substanti¬ ally a form of a gutter 10a, 10b and 10c, respectively, extending along the bulkhead wall, said gutter extending along and having the same extension as the recesses 8a, 8b, 8c at the bottom portion of the respective bulkhead wall 3b, 3c, 3d, respectively.

If necessary there may in each recess 8a-8c be provided a substantially vertical hatch (not illustrated) which is adapted to close the respective recess during certain con¬ dition of operation or use.

It is to be understood that each screw conveyor 8a-8c at its one end communicates with a respective vertical conveyor 4a, 4b and 4c, respectively said latter vertical conveyors for example comprising a bucked elevator for lifting loose mass above the deck 10, each of said vertical conveyors 4a-4c at its upper end being connected to a common transportation path 11 provided substantially in the longitudinal direction of the vessel 1.

The transportation path 11 which communicates with the indi- vidual vertical conveyors 4a-4c is at the one end, namely the unloading outfeed end 11a adapted for being connected to a longitudinally extending unloading device 12, see especi¬ ally Fig. 5, which at the unloading end of the common tran-

sportation path 11 is provided pivotably around a horizontal axis extending in the direction of the common conveyor, as well as a vertical axis in the area of the unloading end.

As especially appearing from Fig. 1 , 2 and 3 the individual scraper devices, as this is illustrated in the scraper device 5b illustrated in Fig. 1, are mounted on a carriage 13 which can move along a bulkhead wall, here on the one side of the bulkhead wall 3b illustrated in Fig. 1, and which can be displaced along rails 14 provided along the bulkhead wall. Said rails 14 serve not only as travelling rails for the individual carriage 13, but also as a rein¬ forcement of the bulkhead walls having the recesses 8a-8c cut out therein, for thereby providing space for the above discussed, screw conveyors 6a, 6b and 6c, respectively.

As appearing from Fig. 3 there are on each side of a bulkhead wall, here for example the bulkhead wall 3c, mounted travel-ling rails 14 on each side, preferably at the same hight, such that the respective carriage 13 may be displaced forth and back as this is illustrated by the double arrow 15 in Fig. 1.

Preferably each scraper device 5a-5f may take the _^ . r of a chain conveyor 16 including catches 16a, and each craper device 5a-5f may at each end be provided at the lower area of a raisable and lowerable preferably vertically arranged rod 17 which is mounted on the respective carriage 13, and which may be pivoted about its substantially vertical axis. At a portion at a distance from the carriage rod 17 the respective scraper device 5a-5f is attached in a rope 18, for example two ropes which may have their length adjusted from deck level, for example by being suspended in appropri¬ ately ©perafcfed winches.

As appearing from Fig. 1 also the scraper device 5b may have its inner end 5x raised and lowered in pace with the raising and lowering movements of the rod 17 which is mounted on the

carriage 13, which is symbolized by the double arrow 20. At the same time the scraper device 5b may also be pivoted about the vertical axis of the rod 17, which is symbolized by the double arrow 21. In addition the scraper device 5b may have its front portion 5y raised and lowered by means of the ropes 18, which is symbolized by the double arrow 22, and finally the overall scraper device 5b may be displaced together with the carriage 13 by the latter's movement for- wardly and rearwardly between the sides of the ship, here symbolized by said double arrow 15.

By this system also the scraper devices 5a-5f may effect a sweeping across the whole bottom of the hold 2b in which the scraper device is mounted, and the angle of the individual scraper device may be adjusted in relation to the downstream angle of the loose masses in question, that is when the out- feed has proceeded so far that a downstream angle becomes important.

The individual carriage 13 in each hold may appropriately be provided so hight above the bottom 7 of the ship that the inner end 5x of for example the scraper device 5b is a little ^•■ 'bove the downstream material when this after the outfeed .. γ means of gravitation through the screw conveyors 6a-6c tc...- _s a certain downstream angle, for example in the range of 30°. At the same time the length of the scraper device 5b may be dimensioned to approximately half of the length of the respective hold, for thereby securing that the scraper device may be swept into the innermost- corner of the hold in question.

In the forth and aft hold 2a and 2d there will in connection with the discussed embodiment appear rest masses in the vicinity of the bulkhead walls thereof, 3a and 3e, respec- tively, and such rest masses may be unloaded by means of for example a wheel loader which possibly may follow the ship.

Possibly, the scraper devices of the forth and aft hold may

be provided with lengths which are larger then half of the hold length.

In the discussed embodiment of an unloading system according to the invention there is provided a principle solution for a quick and effective self-unloading of loose masses in a bulk ship. The discussed equipment is adapted for loose masses, but due to its relatively simple design it may in an appropriate manner be parked or mounted along one of the sides of the ship, and consequently give room for transpor¬ tation of any other type of load without any mentionable reduction of loading space.

The unloading system may easily be adapted to already exist- ing bulk ships, since there between each hold 2a-2d are mounted said screw conveyors 6a-6c, which may be hydraulic- ally operated. Each of said screw conveyors 6a-6c feeds a bucket elevator 4a-4c which lift the loose masses above deck, and pass the loose masses to the common transportation path 11 which in turn brings the masses to the pivotable, elongated unloading device 12 which may undertake unloading approximately 20-25 m from the side of the ship.

At the start of the unloading the loose masses, as indicated by the reference numerals 23 in Fig. 4, will be fed out through the screw conveyors 6a-6c, said transportation mas¬ ses 23 streaming down to the area of said screw conveyors 6a-6c under the influence of gravity. After a certain time the loose masses 23 will take the shape of a wedge 23a hav- ing a downstream angle of for example 30°, and the transpor¬ tation out from the holds 2a-2d must then be aided by the discussed scraper devices 5a-5f. By means of the carriage 13 and the rod 17 thereof, as well as by means of the ropes 18 the scraper devices 5a-5f may be adjusted in relation to said downstream angle and carry out an effective scraping of the wedge shaped downstream goods 23a, namely in the direc¬ tion of the screw conveyors 6a-6c. Due to the condition that the screw conveyors 6a-6c do not extend across the complete

width of the hold, there will appear loose mass which not by itself streams down to the screw conveyors. By an appro¬ priate location for length of the respective scraper devices 5a-5f these may, however, sweep across the complete bottom of the boat, since the angle is adjusted by means of said ropes 14. Because the length of the scraper devices 5b-5d is approximately equal to half of the hold length, it is possi¬ ble in connection with the final emptying to locate the individual scraper devices such that the same will sweep across so to say the complete bottom of said hold. By reversing the operating gear of the conveyor band 16 of the individual scraper devices 5b-5d also the remaining material of the hold corners may be pulled out on the bottom, and be transported therefrom, by appropriate adjustment of one or more respective scraper devices , to the area of the gutter 10a-10c in question, positioned below the individual screw conveyor 6a-6c.

In Fig. 4 there is illustrated how the various scraper devices 5a-5f, respectively, may take various positions of operation, especially in the final phase of the unloading, i.e. when only a little of loose masses remain in the indi¬ vidual holds 2a-2d. In the stage of operation as illustrated in Fig. 4, the scraper devices 5a and 5b work towards the common screw conveyor 6a, whereas the two scraper devices 5c and 5d work towards the common screw conveyor 6b, whereas the two scraper devices 5e and 5f work towards the common screw conveyor 6c.

It is to be understood that the invention may be implemented in other manners then what have been described above. For example, the length of the individual scraper devices may be dimensioned such that they will extend across the complete length of the hold, which means that only one scraper device is necessary in each hold.

Further, it is to be understood that a carriage may be used, which is mounted between the bulkhead walls, for example on

further rails running under a right angle in relation to rails running along the bulkhead walls. Also in this case it is sufficient with only one scraper device in each inter¬ mediate hold.

It -3-S to be understood that a combination of the above dis¬ cussed embodiments may be utilized in one and the same ship.