US3329287A - Method and apparatus for suction unloading of sand barges - Google Patents

Description

Jul 4, 1967 METHOD AN J. DE KONING 3,329,287

D APPARATUS FOR SUCTION UNLOADING 0F SAND BARGES Filed April 3, 1965 3 Sheets-Sheet 1.

(PRIOR ART) IN VENTOR JAN de KoNi/vc:

BY Mvyg ATTORNEY$ July 4, 1967 J. DE KONING 3,329,287

METHOD AND APPARATUS FOR SUCTION UNLOADING OF SAND BARGES Filed April 5, 1965 5 Sheets-Sheet FIGS J'AN dc /(ONI'NG- BY 1M ATTORNEYS July 4, 1967 METHOD AND J. DE'KONING 3,329,287 APPARATUS FOR SUCTION UNLOADING OF SAND BARGES:

Filed April 5, 1965 3 Sheets-Sheet, F

INVENTOR JA N de KoNiNG ATTORNEYS United States Patent 3,329,287 METHOD AND APPARATUS FOR SUCTION UNLOADING 0F SAND BARGES Jan de Koning, Amsterdam, Netherlands, assignor to N.V.

Ingenieursburean voor Systemen en Octrooien Spanstaal, Rotterdam, Netherlands, a Dutch manufacturing company Filed Apr. 5, 1965, Ser. No. 445,395 Claims priority, application Netherlands, Apr. 7, 1964, 6,403,663 6 Claims. (Cl. 214-14) This invention relates to a method of suction-unloading at least one floating barge filled with sand or some other type of spoil, a washing medium being introduced into the barge and sand together with said washing medium being pumped as a suspension out of the barge to the required destination by means of at least one suction nozzle, the barge being displaced with respect to the suction nozzle during suction-unloading.

In this known method it is inevitable that some of the sand initially in front of the suction nozzle will subsequently be spilt behind the nozzle. In the known method this spilt sand or spillage is washed back towards the suction nozzle with excess water and then sucked in by the nozzle together with the excess water. In this way the barge is always completely or substantially completely unloaded, while the suction nozzle is situated some dis tance away from the gap in the sand to enable the excess water and spilt sand to slow to a position in front of the suction nozzle. I propose to continuously keep the suction nozzle close to the gap in the sand and to move the barge continuously with respect to the suction nozzle during suction-unloading. This gives in some circumstances outstanding advantages despite the fact that the spilt sand remains in the barge. The present invention provides a still further developed method, which has the advantage that the suspension drawn in by the nozzle has a high sand concentration, while the barge is nevertheless completely or substantially completely emptied, this effect being achieved by the fact that a first part of the sand is pumped out of the barge to its destination in the form of a suspension having a high sand concentration, by means of a first suction nozzle, and the remainder of the sand is conveyed to a position near the first suction nozzle by means of a second suction nozzle.

According to the present invention, the spilt sand which remains in the barge in the method according to the abovementioned proposal, can nevertheless be sucked in, so that the method can be advantageously applied in every case, i.e., even if the distance covered by the barges is considerable.

Preferably, during the period when the first part of the sand present in the barge is being sucked in by means of the first suction nozzle, the remainder of the sand in the same barge is being conveyed to the position near the first suction nozzle by means of the second suction nozzle.

When a number of full barges are being successively suction-unloaded, it is preferable for the first part of the sand to be pumped from a specific barge to its destination by means of the first suction nozzle as hereinbefore described, and then for the remainder to be delivered from said barge to the next barge in the form of a washing medium while the first part of the sand from the next barge is being pumped to its destination in the form of a high-concentration suspension.

3,329,287 Patented July 4, 1967 Very fast operation is obtained by the alternate application of the two methods proposed in the preceding two paragraphs. The barges can then be continuously completely emptied by suction successively with very short change-over times.

The invention also covers the novel suction-unloading installation specially adapted to the method of the invention.

It should be pointed out that Dutch patent specification No. 96,078 describes a completely dilferent method of obtaining sand or suction-unloading sand-filled barges, wherein in order to obtain a high-concentration suspension in a delivery pipe a single suction nozzle draws in a suspension having a low sand concentration, the suspension is pumped into a large settling tank constructed in the form of an overflow tank, a high-concentration suspension is pumped from the bottom of the large settling tank into a delivery pipe, while the suspension containing a low sand concentration, which has overflowed from the large settling tank to a smaller tank, is pumped back to a position near the suction nozzle. The high sand concentration of the suspension which it is required to pump into the delivery pipe is controlled by pumping a quantity of suspension out of the smaller tank into the bottom of the large settling tank. This known method is very complicated and in addition to four sand pumps requires two tanks, one of which is of enormous dimensions.

The invention will be explained with reference to the drawing in the following description, which includes additional features to those already mentioned.

In the drawing:

FIG. 1 is a diagrammatic top plan viiew of a barge suction-unloader, showing the known method in which a barge moving alongside the suction-unloader is unloaded;

FIG. 2 is a cross-section on the line I'III in FIG. 1, the suction-unloader being omitted;

FIG. 3 is a similar cross-section to FIG. 2, showing the first step of the method according to this invention;

FIG. 4 is a similar cross-section to FIG. 2, showing the use of another method according to the invention;

FIGS. 5 and 6 are diagrammatic top plan views of a suction-unloading installation for the simultaneous unloading of two barges in accordance with two variants of the method according to the invention;

FIGS. 7 and 8 are diagrammatic top plan views of a suction-unloading installation for the simultaneous unloading of two barges according to another variant of the method according to the invention, the valves in the two figures being shown in different positions;

FIG. 9 is a partial cross-section through a barge unloaded by suction according to yet another variant of the method according to the invention.

In the known method illustrated in FIGS. 1 and 2, a suction unloader 1 comprising two water pipes 4 and 5 fed by a water pump 19, a nozzle 2 at the end of a suction pipe 3, and a sand pump 20 connected to the suction pipe 3, draws the sand from a barge 6 and conveys it to its destination via a delivery pipe 21 connected to the sand pump 20.

During suction unloading, the barge 6 is hauled successive distances in the direction of the arrow 11 through the agency of a cable 8 which is partly wound on a driven winch 7 and which runs via a guide sheave 9 on the suction unloader to a bollard 10 on the barge, the mooring line 12 securing the barge 6 to the suction unloader 1 being paid out successively.

When a barge 6 filled with solid sand 13 has tied up along the suction unloader 1, the sand situated in the forepart of the barge is loosened with water from the water pipe 4 .and then the suction nozzle 2 is lowered into the loosened sand. While this sand is sucked in together with the water from the pipe 4, the nozzle 2 continuously descends as far as the bottom of the barge 6 where it sucks away the surrounding sand for some time. The sand sticking to the forepart edge 17 of the barge 6 is then washed towards the nozzle 2 by means of water from the pipe -5. During this process, an increasing amount of sand arrives from the gap which has formed on the right of the suction nozzle in FIG. 1. This sand is taken up by the suspension 16 surrounding the suction nozzle. The said gap thus moves continuously away from the nozzle 2. As soon as the forepart of the barge 6 has been emptied, the barge 6 is hauled along in the direction of the arrow '11 so that after such operation the suction nozzle is at a smaller distance from the gap. A concave ap 14 thus forms after a number of hauling operations, as show in FIGS. 1 and 2.

When the sand 15 adhering to the sides drops down, most of it will assume a position behind the suction nozzle 2 in the form of spillage sand 18. As the suction nozzle 2 increasingly approaches the gap 14, there will of course be an increasing amount of spillage 18. The suction nozzle 2 is therefore kept a considerable distance away from the gap 14. Also, the spillage 18 can readily be washed to a position in front of the nozzle 2 by means of water from the pipe 5. As a result of this system, the suspension 16 in front of the nozzle has a relatively low sand concentration. The extraction of the last remnant of sand from the barge 6, in particular, is at the expense of a very low sand concentration in the extracted suspension.

As shown in FIG. 3, with the method according .to the invention, the nozzle 2 is held close to the gap 14. The barge 6 is hauled continuously in order continuously to follow the gap 14 despite the fact that sand is continuously being sucked from and out of said gap, so that the suspension drawn in continuously has a high sand concentration. As a result of this new method there is a considerably larger amount of spillage 18 behind the suction nozzle 2, but such spillage is not washed back with excess water as in the known method. In many cases, more particularly when the barge 6 is filled with fine sand and the barge route is relatively short, it is more economic to leave the spilt sand in the barge 6 and return the barge only partly unloaded to the dredging site, than to transport the sand through the delivery pipe with an excess of water at the expense of a considerable power loss. Preferably, however, as shown in FIGURE 4, the barge is in any case not returned to the dredging site only partly unloaded. The spilt sand 18 can in fact be very elegantly removed from the barge by sucking the same up as a suspension with, if necessary, a low concentration, by means of a second suction nozzle 22, and conveying it to close to the first suction nozzle 2 by means of a second sand pump 23 and a pipe 24.

This first suction nozzle 2 and the second suction nozzle 22 may be located in the same barge 1 as shown in FIG- URE 4 or the first suction nozzle 2a may be located in the one and the second suction nozzle 22a in the other of two barges described in connection with FIGURES through 8. In addition to being conveyed directly to a position close to the first suction nozzle, the spilt sand can be so conveyed indirectly, for example via the slope of the solid sand. In this way the suspension acts as a washing medium and the water supply via the pipe 4 can be reduced or stopped. In this way a high sand concentration is obtained in front of the sand suction nozzle 2. The pipe 3 should be of a length such that any overflow from the suction pipe or the sand pump 20 in conjunction with the vacuum and the required concentration are at the correct level so that the required concentration cannot be exceeded.

The floating suction unloader 1a illustrated in FIG. 5 is intended for the performance of a more developed method according to the invention and is completed by a spud barge 25 both ahead and astern. Two mooring stages are thus provided for the barges 6a and 6b. Apart from the usual sand pump 20a, which pumps the sand to its destination by means of the suction nozzle 2a, suction pipe 3a containing the valve 29, and the delivery pipe 21a, and the usual water pump 19a which, when the valves 26, 27 and 28 are open can pump Water to the delivery pipe 21a, water pipe 5a and water pipe 5b respectively, the suction unloader 1a also includes a second sand pump 23a which can convey a suspension of water and sand from the barge 6b to the barge 6a by means of the second suction nozzle 22a and the pipe 24a.

The barges are unloaded by suction as follows: firstly, barge 6b is tied up to the suction unloader 1a in the position of barge 6a beneath the suction nozzle 2a and valve 27 is opened while water is pumped into the barge to act as a washing medium. The suction nozzle 2a is then lowered into the barge 6b, which is partly emptied as described in connection with FIG. 3, so that the spilt sand 18 remains in the barge because of the continuous dis placement of barge 6b with respect to nozzle 2a. The barge 6b and the still completely full barge 6a are subsequently tied up in the positions shown in FIG. 5 and respectively beneath the second and first suction nozzles 22a and 2a. During this change of the barges, valve 29 is closed and valve 26 is opened to deliver water in the delivery pipe 21a to maintain conveyance in said pipe. After the barges have been changed over, valve 28 is opened to supply water to barge 6b, the spillage sand 18 is delivered to barge 6a by means of the second suction nozzle 22a, pump 23a and pipe 24a, and the sand from barge 6a is pumped to its destination, through the agency of nozzle 2a, suction pipe 3a, sand pump 20a and delivery pipe 21a, in the form of a high-concentration suspension, by the barges 6b and 6a being moved at a speed such that the suction nozzle 2a is continuously situated in a high-concentration suspen- SlOIl.

Of course the barge 6b must be moved at a constant speed if the barges 6a and 6b are situated fairly close together, to avoid obstruction of barge 6a by barge 6b. To this end, the two barges may for example be secured to a single haulage system. If desired, the suction nozzles 2a and 22a may be disposed far apart or on either side of the suction unloader if the barges 6a and 6b are required to be displaced at independent speeds.

When the furthest left portion of the barge 6a with reference to FIG. 5 has arrived at the nozzle 2a, a certain quantity of spilt sand 18 will be left in this barge, while the barge 6b is practically completely empty. Finally, barge 6b can disappear and barge 6a occupy its position, whereupon the process can be continuously repeated with other filled barges 6.

In FIG. 6, the suction unloader 1a is situated in the Water at such a distance from the quay that barges 6 can be tied up on each side. In fact four mooring stations 32 are thus created for barges 6, stations 32a and 32a being the same in principle as station 32a, while stations 32b and 32b" are the same as station 32b in FIG. 5. With the valves 29' and 29" open, the sand pump 20a and the suction nozzles 2a and 2a" respectively can draw sand in a high concentration from the barges 6 at the respective stations 32a and 32a", while in the latter barges, with the valves 30a and 30a" respectively open, and depending upon whether the valves 30b and 30b" are open or closed, washing water together with spillage sand can be conveyed out of the barges 6 at the respective stations 32b and 32b by means of the said pump 23a and the respective nozzles 22a and 22a".

The spillage sand may or may not be pumped over crosswise.

An advantage of the suction unloader according to FIG.

6 is that during unloading of a still completely full barge and a barge filled with spillage sand at two of the four moorin stations, the barges 6 at the other mooring stations can be changed over so that a suction nozzle 2a and a sand suction nozzle 2b are always drawing sand. With this system of changing over the barges, no water without sand has to be pumped into the delivery pipe 21b during the barge changeover.

The suction unloader shown in FIGS. 7 and 8 has a mooring station 320 on each side, such station being arranged in the same way as station 32 in FIG. 5. The connection of the sand suction nozzles 2c, sand pumps 200, water pump 19c, pipes 240 and delivery pipe 21 is variable through the agency of a number of valves, as shown in FIGS. 7 and 8.

For the sake of clarity, the connecting pipe between the water pipe 19 and the sand pumps 20c has been omitted from these two figures.

The identical sand pumps 20c are each driven by a separate electric motor (not shown), the two motors being supplied with current by a single generator (not shown).

When the valves are in the position shown in FIG. 7, water is pumped into the barge 6c filled with spillage sand, the spillage sand is delivered out of this barge into the sand-filled barge 60 through the agency of nozzle 22c", sand pump 20c" and pipe 240', sand pump 20" and pipe 24c, and a suspension containing a high concentration of sand is transported to its destination from the barge 6c through the agency of the nozzle 20', sand pump 20c and delivery pipe 21c, while the two barges are being hauled along. When barge 6c contains only spillage sand and the empty barge 6c has been replaced by a completely full barge 6d, the functions of the suction nozzles and sand pumps are changed over by adjusting the valves to the positions shown in FIG. 8, water now being delivered from pipe 40 into the barge 6c, the spillage sand being delivered out of this barge into barge 6d through the agency of the suction nozzle 22c, sand pump 20c and pipe 240", and a suspension contain-ing a high concentration of sand being again delivered to its destination through the agency of the suction nozzle 2c", sand pump 20c" and delivery pipe 210.

The pipe 24 leading from the second suction nozzle 22 to the first suction nozzle 2 need not necessarily contain a sand pump 23. If the second suction nozzle 22d has its pipe 24d connected to the first suction nozzle 2d (see FIG. 9), the normal sand pump 20 will draw in a considerable amount of sand through the first suction nozzle 2d and a relatively considerable amount of water through the second nozzle 22d. If the barge 6 is drawn along too rapid- 1y, a large plug of sand will form in the first nozzle 2d so that the resistance in the latter increases and more suspension is drawn in by the second nozzle 22d. This suspension containing a relatively low concentration of sand then dissolves sand from the top part of the first suction nozzle 2d. If the ratio of the resistances in the first suction nozzle 2d and the pipe 24d, and the exact speed of haulage of the barges are respectively suitably chosen, an optimum sand concentration can be obtained in the suspension conveyed by the delivery pipe 21. For simple control of the latter ratio, for example, a valve 31 may be provided in pipe 24d and/ or in the first suction nozzle 2d. A suitable place for this valve 31 is, for example, the

point of conection of the pipe 24d and the first suction nozzle 2d.

An advantageous continuous suction process is possible if a number of barges 6 is hauled along in the same direction with respect to the two consecutive suction nozzles 2 and 22. After a certain time, the position shown in FIG. 4 will occur, in which the two suction nozzles 2 and 22 are inserted into the same barge 6. Some time later, after the suction nozzle 2 has reached the end of the barge 6 but has not necessarily run dry, said suction nozzle 2 is immediately transferred to the next barge 6' which is in the ready position astern the barge 6, while the suction nozzle 22 remains in the barge 6 to suck up the spillage sand 18. The end of the pipe 24 is then also held over the barge 6' so that the spillage sand can be injected into barge 6 from barge 6 in the form of a suspension.

After insertion of the suction nozzle 2, barge 6' can immediately be hauled along with respect to this nozzle, because the sand sticking to the leading edge 17 behind the nozzle 2 is sucked in by the second suction nozzle which is subsequently introduced into the barge 6'. It will be apparent that by successively unloading a number of barges 6 by suction in the above described manner a continuous suction process is obtained in which the barge changeover times are zero and the suspension drawn in by the first suction nozzle 2 continuously has a high concentration of sand, because said suction nozzle 2 is continuously in or close to the full gap 14 in the sand, whlle the barges are nevertheless satisfactorily unloaded because the spillage sand 18 and the sand sticking to the front and rear walls is sucked in by the second suction nozzle 22.

I claim:

1. A method of suction-unloading at least one float ng barge filled with sand or the like, the method comprising the steps of:

introducing a washing medium into the barge;

pumping the sand and the washing medium in suspension from the barge to a desired location by the action of successively employed first and second suc tion nozzles;

the barge being advanced with respect to the first suction nozzle in relation to the progress of the pumping operation;

the initial pumping operation of the first nozzle being of a suspension containing a high ratio of sand to pumping medium; and

further conveying the remaining sand to the location of the first nozzle by actuation of the second nozzle.

2. The method of claim 1, wherein:

the pumping of the sand by action of the first nozzle and the conveyance of sand to said location by actlon of the second nozzle are carried out coextensively.

3. A method of suction-unloading a plurality of floating barges filled with sand or the like, the method comprising the steps of:

introducing a washing medium into an initial barge;

pumping the sand and the washing medium in suspension from the first barge to a desired location by action of a first suction nozzle;

introducing a washing medium into the remaining barges in succession;

pumping the sand and the washing medium from the succeeding barges to said desired location by action of successively employed suction nozzles;

the barges being advanced with respect to the said suction nozzles in relation to the progress of the pumping operation;

the initial pumping operation of the first nozzle of each barge being of a suspension consisting of a high ratio of sand to pumping medium; and

conveying the remaining sand of each barge to the next succeeding one thereof by the action of a second nozzle.

4. The method of claim 3, wherein:

the actions of the second nozzles are performed simultaneously with the actions of the first nozzles.

5. The method of claim 3, wherein:

the advance of the barges with respect to one another is continuous and is synchronized with the action of the respective suction nozzles.

6. Apparatus for the suction-unloading of floating barges filled with sand or the like, the apparatus comprising:

a washing pump having an inlet connected to a source of washing medium and an outlet;

a first sand pump having an inlet and an outlet leading to a sand accumulation region;

a first suction nozzle connected to the inlet of said first sand pump;

a discharge nozzle connected to the outlet of said washing pump and disposed to direct washing medium against a mass of sand within a barge at a point adjacent said first suction nozzle;

a second sand pump having an inlet and an outlet; 21 second suction nozzle connected to the inlet of said second sand pump and disposed to draw sand suspended in washing medium from a barge remote from said first suction nozzle; and

a second discharge nozzle connected to the outlet of said second sand pump and disposed to discharge sand suspended in washing medium against a mass of sand adjacent said first suction nozzle.

References Cited UNITED STATES PATENTS GERALD M. FORLENZA, Primary Examiner.

ROBERT G. SHERIDAN, Examiner.

Claims (2)

1. A METHOD OF SUCTION-UNLOADING AT LEAST ONE FLOATING BARGE FILLED WITH SAND OR THE LIKE, THE METHOD COMPRISING THE STEPS OF: INTRODUCING A WASHING MEDIUM INTO THE BARGE; PUMPING THE SAND AND THE WASHING MEDIUM IN SUSPENSION FROM THE BARGE TO A DESIRED LOCATION BY THE ACTION OF SUCCESSIVELY EMPLOYED FIRST AND SECOND SUCTION NOZZLES; THE BARGE BEING ADVANCED WITH RESPECT TO THE FIRST SUCTION NOZZLE IN RELATION TO THE PROGRESS OF THE PUMPING OPERATION; THE INITIAL PUMPING OPERATION OF THE FIRST NOZZLE BEING OF A SUSPENSION CONTAINING A HIGH RATIO OF SAND TO PUMPING MEDIUM; AND FURTHER CONVEYING THE REMAINING SAND TO THE LOCATION OF THE FIRST NOZZLE BY ACTUATION OF THE SECOND NOZZLE.

6. APPARATUS FOR THE SUCTION-UNLOADING OF FLOATING BARGES FILLED WITH SAND OR THE LIKE, THE APPARATUS COMPRISING:

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