CA1160978A - Method of transporting coal and ships for transporting coal slurries - Google Patents

Abstract

TITLE OF THE INVENTION
METHOD OF TRANSPORTING COAL AND SHIPS
FOR TRANSPORTING COAL SLURRIES

ABSTRACT OF THE DISCLOSURE
A method of transporting coal in which coal sent forward in the form of a slurry is classified in accordance with the particle size of the coal, and the coal slurry other than a fraction thereof containing the fine particles not larger than a specified size is transported by a ship.

Description

~L~6Q~`~8 This invention relates to a method of transporting coal slurries by ship.
Generally coal is transported on the land from coal mining areas to loading ports, where it is loaded into ships for transport on the sea. To reduce the cost of transport, it is common practice in recent years to pulverize coal to particle sizes of up to several millimeters and disperse the particles in water to obtain a coal slurry in the mining area, transport the coal slurry to a loading port through a pipeline and load the slurry into a ship for transport. With slurry transport ships, the coal slurry must be dewatered to the greatest possible extent during loading or navigation to achieve improved transport efficiency and reduced transportation costs. However, when the coal slurry delivered through a pipeline is loaded as is into the ship, it is extremely difficult to dewater, as will be described below. When a slurry of large coal particles is conveyed through the pipeline, the slurry is easy to dewater after transport but causes marked wear on the pipe and requires a relatively high flow velocity, con-sequently necessitating increased power consumption and entailing ~20 higher transportation costs. Conversely a slurry of exceedingly small particles has a high viscosity and requires increased power ~ consumption for transport. Thus the coal slurry to be transported : ~ :

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1~609t78 has an optimum particle size distribution from the point of view of the transportation costs. For this reason, the slurry to be conveyed is adapted to contain large coal particles, for example, of about several millimeters in maximum size, and also fine coal particles of up to several tens of microns in an amount not smaller than a specified proportion. When loaded into a hold, such coal slurry initially contains the coal particles substantially uni-formly dispersed therein, but with the lapse of time, large particles settle to form a lower layer under an upper layer of -suspended small particles. Slurries in holds are dewatered usually by drawing off water through a drain opening formed in the bottom of the hold and provided with a filter. If the above-mentioned coal slurry containing fine particles is drained by this method, the small coal partic}es suspended in the upper layer will pro-gressively cover the lower layer of large coal particles during draining, consequently closing the interstices, namely water channels, in the lower layer. ThiS leads to a reduced drainage efficiency, or in an extreme case, makes it impossible to drain the slurry. Additionally small coal particles are likely to clog the filter and result in a lower dewatering efficiency.

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~ ~ -3-, ~ ~9';~8 SUMM~RY OF THE IN~IENTION
An object of the present invention is to provide a method of transporting coal in which the coal loaded into a ship in the form of a slurry can be dewatered with ease and can therefore be transported on the sea with an improved efficiency.
Another object of the invention is to provide a method of transporting coal by which coal can be transported from the mining area to a loading port on the land at a reduced cost.
The invention provides a method of transporting coal comprising slurrying pulverized coal at a coal minlng area and transporting the coal slurry through a pipeline to a loading port, classifying this slurry at the loading port in accordance with coal particle size into a fine slurry fraction containing fine particles of a size not larger than the specified one and a coarse slurry fraction excluding such fine particles, transporting the coarse slurry fraction by ship while returning at least a portion of the fine slurry fraction through a pipeline to the coal mining area, admixing the returned fine slurry fraction with newly pulverized coal particles to make a slurry, and transporting this ~20 slurry through the pipeline to the loading port.
A coal slurry transport ship is disclosed in which coal ~: in the form of a slurry can be loaded into its hold and dewatered to the greatest possible extent to achieve an improved transport ef f iciency .

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~978 BRIEF DESCRIPTIoN OF THE DRAWINGS
Fig. 1 is a flow chart showing a method of ~his invention;
Fig. 2 is a view in vertical section showing a slurry separator;
Fig. 3 is a perspective view showing an apparatus for concentrating and solidifying a slurry of fine coal particles;
Fig. 4 is a perspective view showing a modified slurry separator;
Fig. 5 is a perspective view shcwing another modified sluLry separator;
Fig. 6 is a view in longitudinal section showing a hold portion of a ooal slurry transport ship embodying the inventian;
Fig. 7 is a perspective view shcwing the hatch portion of the hold;
Fig. 8 is a view in vertical section partly broken away and showing a drain tube;
Fig. 9 is a side elevation partly broken away and shawing means for raising and lo~ering the drain tube;
Fig. 10 is a plan view of Fig. 9;
Fig. 11 is a view in langitudinal section of a hol1 portian for showing a modified structure for supporting the drain tube;
Fig. 12 is a perspective view partly broken away and showing a hold portion o another coal slurry transport ship embcdying the inventian;
; Fig. 13 is a view in longitudinal secticn showing the same;
Fig. 14 is a frag~entary view in longitlld;n~l section showing a mLdi-fied water guid~e;
Fig. 15 is a fragmentary view in langitudinal section showing anokher mLdified water guide;
Fig. 16 is a front view of Fig. 15;
Fig. 17 is a view in section taken alang the line S17 ff l7 in Fig. 16;
Fig. 18 is a view in longitudinal section shcwing a hold portion of anoth~r ooal slurry transport ship cmbodying the inventian;

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'7~3 Fig. 19 is a view in SeCtiQn taken along the line Sl9-Sl9 in Fig. 18;
Fig. 20 is a view in lQngitud m al section showing a hold portion slightly different fram the one shown in Fig. 18;
Fig. 21 is a cross sectional view shcwing another coal slurry transport ship of the invention;
Fig. 22 is a plan view of Fig. 21;
Fig. 23 is the combination of a perspective view shcwing a turning arm and a view in vertical sectiQn showing rotating means and vertically mDving means therefor as arranged in corresp~nding relatian;
Fig. 24 is a view in section taken alQng the line S24-S24 in Fig. 23;
Fig. 25 is a front view for illustrating the operation of the turning arm, Fig. 26 is a fragmentary bottam view showing a modified turning arm, Fig. 27 is a front view showing another modified turning arm;
Fig. 28 i5 a fragmentary plan view showing anokher ooal slurry trans-port ship e~bcdying the inv~ntion;
Fig. 29 is a view in section tak~n along the line S29-S29 in Fig. 28;
Fig. 30 is an enlarged view in section taken along the line S30-S30 in Fig. 28;
Fig. 31 is a fragmentary side elevation partly broken away and showing a screw canveyor an an enlarged scale;
Fig. 32 is a side elevatian partly brbken away and showing a modified screw oon~eyor;
Fig. 33 is a fragmentary enlarged view in section of Fig. 32;
Fig. 34 is a flow chart showing another method em~cdying the invention;
~; ~ Fig. 35 is a diagram showing a system including a granulating apparatus and a~apted to practi oe the methcd of Fig. 34;

09'78 Fig~ 36 is a flow chart showing another method of the inv~ntion;
Fig. 37 s a flow chart showing another method of the inventian;
Fig. 38 is a fragmentary view in longitudinal section showing another ooal slurry transport ship enbcdying the invention;
Figs. 39, 40 and 41 are cross sectianal views showing a hold portion of Fig. 38;
Fig. 42 is a perspective view partly broken away and showing the hold portion;
Fig. 43 is a fragmentary view in langitudinal sectian show m g another ooal slurry transport ship embodying the invention;
Fig. 44 is a fragmentary perspective view partly braken away and show-ing another coal slurry transport ship embodying the inventian;
Fig. 45 is a fragmentary perspective view showing a hold of Fig. 44 an an enlarged scale;
Fig. 46 is a perspective view showing separators in Fig. 44 on an en-larged scale;
Fig. 47 is a cross sectional view corresponding to Fig. 46;
Fig. 48 is a fragmentary frant view partly braken away and showing a slurry transfer duct in Fig. 44 an an enlarged scale;
Fig. 49 is a view in section taken along the line S49-S49 in Fig. 48;
Fig. 50 is a frant view partly broken away and showing a mcdified slurry transfer duct;
Fig. 51 is a botto~ view oorresponding to Fig. 50;
Fig. 52 is a front view partly broken away and showing anokher modified slurry transfer duct;
Fig. 53 is a view in langitudinal section showing a hold portion of another ooal slurry transport ship embodying the invention;

Fig. 54 is a plan view showing the same;
Fig. 55 is a front view showing means for adjusting the angle of turn of a nozzle mounting pipe;
Fig. 56 is a view for illustrating t~e cperation of injection nozzles;
Fig. 57 is a view in longitudinal section showing a hold portion of another ooal slurry transport ship embodying the invention;
Fig. 58 is a plan view showing the hold portion of Fig. 57;
Fig. 59 is a perspective view showing a flap and means for mcving the flap;
Fig. 60 is a fragmentary vi~ew in section showing the relation between the flap and a guide rail;
Fig. 61 is a sid~e elevation of Fig. 60;
Fig. 62 is a perspective view po~tly braken away and showing another ooal slurry transport ship enbcdying the invention;
Fig. 63 is an enlarged view in ~ertical sectian showing a tray of Fig.
62;
Fig. 64 is a vi~ew in ~ertical section showing a modified tray;
Fig. 65 is a plan view schematically showing a transport ship and system for practicing another method of the invention; and Fig. 66 is a schematic diagram showing a granulating and classifying ,~
apparatus.
~- ~; DESCRIPTION OF T9E PREFERRED EMEODIMENTS
Fig. 1 is a flow chart shcwing a methcd of this invention.
With referen oe to Fig. 1, ooal is pulverized by a coal mill 2 installed at a coal mining a~ea 1. The ooal is pulverized to particles up to about 3 mm if lar~est and about 0.1 to about 0.4 mm in average size. The pulverized ooal is supplied to a slurry preparing apparatus 3 to obtain a slurry oontaining about ~609'~8 50% by weight of water. The particle size distribution of the pulverized coal and the concentration of the slurry are determined in view of the distan oe of transport of the slurry, the wear to be produced on the transport pipe, the pos-sible clogging of the pipe, the quality of the coal, the characteristics of the coal mill 2 and the like. Thus the distribution and concentration are suitably variable in accordan oe with variations of these conditions. The coal slurry is transported through a pipeline to a loading port, where the slurry is separated by a slurry separator 4 into a fine particle coal slurry containing fine part-icles of 0 to 0.15 mm in size and a coarse particle slurry containing coarse part-icles of 0~15 to 3 mm in size. The particle size of 0.15 mm is thus set as the separation standard because it is difficult to dewater slurries containing fine particles of not larger than 0.15 mm in size. However, the separation standard is variable in accordan oe with the quality of the ooal and okher conditions.
Fig. 2 shows an example of useful slurry separators 4. The illustrated separator 4 oomprises an agitation tank 6 provided at its bottam portion with agitating blades 5 for directing the contents of the tank upward. An inlet duct 7 for a o~al slurry feed and an outlet duct 8 for a ooarse particle slurry are disposed on opposite sides of the tank 6 at its lower portion. At an upper portion of the tank 6 a fine particle slurry outlet duct 9 is provided at the same side as the slurry inlet duct 7. m e fine particle fraction of the ooal slurry introducedinto the tank 6 through the inlet duct 7 mDves upward in the tank 6 and flows out from the outlet duct 9, while the coarse particle fractian æ ttles in the lcwer portion of the tank 6 and flows out from the outlet duct 8.
m e ~n~rse particle ooal slurry thus sep æ ated is tempor æ ily stored in a storage pond 10 and then loaded into the hold of a first transport ship 1l.
m e ooal slurry is dewatered during navigatian for a reductian of its weight to les æ n the load, whereby the water content of the coal slurry to be disch æ ged at _g_ a port of delivery is reduced to about 10~ by weight. m e coarse particle coal in the form of a solid mass is discharged onto the wharf of the port of deli~ery with a grab, or as oonverted to a slurry again. The coarse particle slurry thus loaded into the transport ship 11 and free fine particles of up to 0.15 mm in size is easier to dewater and can be transported mare effi d ently and much less e~pensively than the unseparated coal slurry cQntaining such fine particles.
on the other hand, the fine particle ooal slurry separated is fed to an apparatus 12 for oan oe ntrating and solidifying the slurry. Fig. 3 shows a useful example of such apparatus 12. The illustrated apparatus 12 ccmprises a ooncentra-tion tank 14 having a slanting bottom wall 13 and a header 15 at its upper end.
The header 15 has a large number of slurry inlets 16 opened to the interior of the tank 14. A slurry collecting cha~nel 17 extends widthwise of the tank 14 at its lower end. A slurry return duct 18 having a pump 19 thereon extends fm m one end of the channel 17 to the header 15. m e tank 14 has at one side thereof a solid coal outlet 20 from which a slanting plate 22 for guiding solid coal ex-tends to a solid ooal depot 21 disposed obliquely below the tank 14 on the same side. m e fine particle slurry is introdu oe d into the con oe ntration tank 14, allowed to flow dcwn the slanting bottom wall 13 and dried in the sun. The slurry portion flowing into and oollected in the channel 17 is returned to the header 15 via the duct 18 and caused to flow down the slanting bottom wall 13 again. In this way the slurry is pr~gressively OQn oe ntrated by being circulated through the apparatus 12 without stagnation. me resulting solid mass of fine ooal particles is forced out fr ~ the outlet 20 to the depot 21 by a bulldozer 23 at a specified time interval. m e solid ooal with a water content of 4 to 5%
by weight is loaded into a second transport ship 24, carried to the port of de-livery and discharged from the ship with a grab. me fine particulate c~al re-maining in the form of slurry in the apparatus 12 is stored in a storage pond 25, .. . . . . .

then loaded into a third transport ship 26, carried to the po~t of delivery and unloaded as a siurry.
Fig. 4 shcws another slurry separator 4 co~prising a plurality of clas-sifying basins 27 arranged side by side in a row. Cpenings 29 formed in the upper ends of the partitions 28 bet~een the basins 27 are positioned in a stag-gered arrangement for overflowing the slurry. The coal slurry fed to the most u~-stream classifying basin 27 (at the left end of Fig. 4) throu~h an inlet 30 flows dc~nstream f m m basin to basin into the mDst dcwnstream basin 27 (at the right end of Fig. 4), overflowing the partitions 28 at the cpenings 29. In the mean-t~me, c ser particles accumulate in upper basins 27, and finer particles inlower basins 27 with respect to the flcw of the slurry.
Fig. 5 sh~ws another slurry separator 4 ocmprising a tray 31 for carry-ing and dewatering slurry provided at the terminal end of the slurry transporting pipeline at the ln~;ng port. m e dewatering tray 31 comprises an upper tray nE~ber 32 and a lower tray me~ber 33. The upper tray member 32 is connected to the pipelinte and has a large number of drain apertures 34 in its bottom and a fiber filter 35 covering the upper surface of the bottam wall and the inner sur-fa oe of its side walls. The upper tray nY~ber 32 is formed in a specified por-tion of its bottom with an op~ning 36 for discharging coarse particle coal slurry.
The filter 35 is cut out at the portion corresponding to the opening 36. In comr municatian with the discharge opening 36, a slurry supply duct 37 extends fram the und2r side of the bottom wall to the bond 10 for the storage of ooarse part-icle ooal slurry~ The lower tray member 33 ooextensive with the upper tray member 32 is disposed below the tray member 32 as spaced t~er,2fram by a specified distan oe for re oe iving the slurry flowing down from the upper tray member 32 and oantaining fine particles. m e terminal end of the upper tray member 32 is oon-nected to the coarse particle slurry storage pond 10, and the terminal end of the 09~8 lower tray nE~d~er 33 to the fine particle slurry storage pond 25. m e lo~er tray member 33 is provided with a vibrab~r 38 for promDting separatian and dewatering of the fed slurry. The fiber filter 35 is fastened to the upper tray member 32 by hoJders 39 ~rranged at spPcified spacing, such that the filter 35 is wholly replaoeable when clogged up.
m e ooal slurry sent forward frcm the mining area 1 through the pipe-line is fed to the upper member 32 of the dewatering tray 31. ~hile the slur~y flows through the upper tray nE~ber 32, a fractian of the slurry oontaining fine particles falls into the lower tray me~ber 33 through the drain apertures 34, flows through the tray member 33 and is collected in the fine particle slurry storage pana. m e ooarse particle slurry separated from the fine particle frac-tian and dewatered to some extent flows into the supply duct 37 through the dis-charge opening 36 in the upper tray me~ber 32 and is led into the coarse particle slur.ry storage pond 10.
Thus the dewaterLng tray 31 oo~prises an upper tray member 32 and a lower tray member 33 disposed below the member 32 and sF~u~d apart therefram by a sEecified distan oe, at least one of the botbam wall and side walls of the up~er tray member 32 being provided with a filter 35 and a multiplicity of dr~in aper-tures 34 for discharging waber cantaining fine particles. Eecause of this oon-structian, the tray 31 classifies the particles in the ooal slurry flowing there-~ throu~h, affording a ooarse particle slurry which has been dewatered to same ex-: tent.
Figs. 6 to 11 show a ship embodying this invention for transporting aooal slurry while dewatering the slurry during navigation.
With referen oe to Figs. 6 and 7, the transport ship has a slurry hold 40 prcvided with four guide tubes 43 ar.ranged around a hatch 41 and exbending through a deck 42. Drain tutes 44 extend downwand into the hold 40 ~with their upper ends inserted in the guide tukes 43.

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m e main body 45 of the drain tube 44 comprises an upper portion serv-ing as a casing portion 46, an intermediate portion as a filt~r portion 47 and alower end portion 48. The filter portion 47 ocmprises an inner tube 49 and an outer tube 50. ~he inner tube 49 is formed with a large number of holes 51 whichare out of ~l;gnment with like holes 52 formed in the outer tube 50. An inner filter 53 of metal netting and an outer filter 54 of nylon or like fiber over the filter 53 are fitted around the inner tube 49 in an annular space within the outer tube 50. m ese filters 53, 54 are tubular. The inner tube 49 has upper and lower threaded ends 49a and 49b which are screwed in the casing portion 46 and the lower end portion 48 respectively. m e outer tube 50 has a threaded upper end 50a screwed on the inner tube 49. Indicated at 55 and 56 are rubber packings. m e lower end portion 48 has a closed lower extremity, is tapered and has an interior spaoe serving as a water arxxn~nDdating spaoe 57. An underwater pump 59 is retained in the lower end portion 48 by a rib 58. The undeIwater pump59 has a downwaLdly opened inlet 59a and an outlet 59b ccnu~x:bed to a drain pipe 60 in the fonm of a flexible hose. m e drain pipe 60 extends outward f m m the drain tube main body 45 c~er a guide roller 61 at the upper end of the casing portion 46. A power supply cable for driving the pump 59 is incorporated into the drain pipe 60.
The guide tube 43 has a pair of rope guide tubes 62. Wire ropes 64 attached to oonnecting members 63 on the lower end of the drain tube 44 and ex-benddng through the rope guide tubes 62 su~port the drain tube 44 in suspension.Each of the ropes 64 is paid off f m m a winch 65 and passed over guide sheaves ; 66 and 67 on the u~per and lo~er ends of the tube 62. m e winches 65, ropes 64, rope guide tubes 62 and guide sheaves 66, 67 constitute means 68 for raising andlowering the drain tube.
m e slu~ry will be drained by the followdng method. The ropes 64 are 9`f`B

paid off from the winches 65 to lower the drain tube 44 along the guide tubes 43 in suspension (as shown on the right side of Fig. 6) and place the drain tube 44 into the layer of slurry. The water in the slurry layer flows into the drain tub,e 44 through th~e holes 51, 52 in the inner and outer tubes 49, 50 and the inner and outer filters 53, 54 and is oollected in the water acoommodating space 57 in the lower end portion 48. m e water is then disch æ ged b~ the pump 59 through the drain pipe 60. The solid oomponent of the slurry is prev~nted from flowing into the drain tube by the filters 53 and 54. L æ ge solids æe unable to pass through the h~les 52 in the outer tube 50. The inner tube 49 supports the filterc 53, 54 against the pressure of-the slursy acting thereon. When the filters 53, 54 have sufficient str~ngth, the inner tub~e 49 can be dispensed with.
After the slurry has been drained, the drain tube 44 is raised by the winc~es 65. The drain tube 44, when tapered in its entirety toward the lower end, can be withdrawn fL~.. the ooncentrated slurry layer easily. A vib~rator, if mounted on the upper end of the drain tube 44, further facilitat~c the withdrawal of the tube. Although the drain tube 44 projects high above the deck when raised, the tube 44 will not beoome an obstacle wh~n the casing portion 46 is rewDved from the threaded end 49a, or if the upper portion of the tube 44 is made bend-able.
As se~en in Fig. 11, the drain tube 44 may be turnably supported at its u~per end by a piv~t 70 cn the under side of a hatch oover 69. In this case, a wLnch 72 is provided on the under side of the hatch cover 69 for taking up a wir~e rope 71 attached to the lower end of the drain tube 44. With this arrangement, the drain tube 44 is used in its vertical suspended position for draining, while it is held along the under side of the hatch oover 69 when out of use as indic-ated in a broken line in Fig. 11. ~he drain tube 44, when thus stored along the under sid~e of the hatch cover 69, does not project ab~ve the deck and will cause no trouble.

W~th the transport ship shown in Figs. 6 to 11, drain tubes having filters are plaoe d into the hold for the remaval of water from the coal slurry, so that the slurry can be dewatered smoothly through efficient preparatory and okher work prooedures.
When the drain tube is adapted to be brought into the hold along guide tubes, the drain tube is easily insertable into and withdrawable from the slurry layer. Especially it is easily withdrawable from the layer in a oan oe ntrated state.
The drain tube, when pivoted to the under side of the hatch oover, can be stored alQng the under side of the hatch oover. This assures effective use of the spaoe available without penmitting the draLn tube to cause some trouble while it is out of use.
Figs. 12 to 17 show another slurry transport ship of the dewatering type.
With referan oe to Figs. 12 and 13, a lateral partition 74 within a hold 73 has at its lower portion a drain opening 76 provided with a filter 75. The water passing through the drain opening 76 is collected in a water re oe ptacle 78 disposed under a bottom plate 77. The water re oe ptacle 78 is ccoclK~bed to an in-let of a drainLng pump 79. The bottom plate 77 is formed at suitable portions with a plur~lity of drain openLngs 80, under which there is prDvided a water receptacle 81 oonnected to the inlet of the draining pump 79. m e drain opening 80 has a perforated plate 82. Fih~r water guides 83 and 84 each in the form of an endless belt are disposed respectively an a oe ntral vertical portion 74a and a lower slanting portion 74b of the lateral partition 74. The water guide is reeved around a pair of arms 85 fixed to eac~l of the vertical and slanting por-tions 74a and 74b. m e opposed upper and lower water guides 83 are in ocntact with or in pr~ximity to each other. The upper water guides 83 are so positioned .

~ ~ ~ 0 * f'8 that their upper ends will be above the layer of coal particles, 86, placed into and settling in the hold 73. The water guides 83 and 84 are made endless so as to be turnable when subjected to the pressure of the particle layer 86 that would otherwise rupture the guide. Water guides 87 of fiber extends an the bottom plate 77 langituA;n*lly thereof. A lateral water guide 89 of fiber at right angles with the langitudinal water guides 87 extends an ~oth the bottom plate 77 and langitudinal partitions 88. m e drain op~nings 80 are positianed under the intersections of the longitudinal and lateral water guides 87 and 89. ~oth ends of the lateral water guide 89 are substantially at the same level as the upper ends of the upper water guides 83. The water guides 83, 84, 87 and 89 may be made of the same mater;~l as the fiber filter, or spange or the like, such that the guide will not be clogged up with particles and is permeable to a liquid only.
Even when a coarse particle coal slurry separated from fine coal part-icles is plaaed in the hold, large particles in the slurry will settle as a lcwer layer with the lap æ of time under an upper layer of small particles. m us the small aoal particles floating to form the upper layer aover the underlying layer of large aoal particles, with the resulting likelihood of closing the intersti oe s (water channels) in the mass of slurry and presenting difficulty in dewatering the slurry.
It is now assumed that when a ooal slurry is loaded into the hold 73 provided with the above means and the pump 79 is operated to dewater the slurry, the water channels thrDugh the layer 86 of particles are clogged up. E~en in this case, the upper ends of the upper water guides 83 and of the lateral water guide 89 æ e positioned above the p æ ticle layer 86, so that the water over the layer 86 is partly led from the upper ends of the upper guides 83 through the guides 83, then through the lower guides 84 to the drain o~ening 76, while the water is also partly led fram the upper ends of the lateral guide 89 through the ' ~Y7B

guide 89 to the drain opPnings 80. aonsequently the water is discharged by the pump 79. Further the water passing through the particle layer 86 and along the outer periphery thereof and reaching the lonyitudinal and lateral partitions 88, 74 and the bottom plate 77 is led through the water guides 83, 84, 87 and 89 to the drain openings 76, 80 for disrh~rge.
Although tw~ kinds of water guides 83, 84 and 87, 89 are used in the above erhxxliment, the la~ral water guide 89 an the longitudinal partitian 88 is replaoe able by endless water guides 83, 84, or conversely, water guides similar to the lateral guide 89 are usable in pla oe of the endless guides 83, 84 on the lateral partition 74.
The two water guides 83, 84 are further replaceable by a single water guide 90 in the form of an endless belt as seen in Fig. 14. m e guide 90 is held by an arm 91 extending along the junction between the vertical portion 74a and the slanting portion 74b of the lateral partitiQn 74.
The endless water guides 83, 84 are further replaceable ky a single station~ry water guide 92 as shcwn in Figs. 15 to 17. Indicated at 93 is an inverted U-shaped frame secured to the lateral partition 74 for hol~;ng the guide 92, and at 94 a holding plate disposed over the outer pPriphery of the guide 92 within the frame 93. m e holding plate 94 is pressed against the guidb 92 by a multiplicit~ of bolts 95 screwed into the hol~ing frame 93.
With the transport ship shown in Figs, 12 to 17 and having water guides provided on suitable portiQns of the inner surfa oe s of the hold and extending to drain opam ngs, water is led through the guides to the drain openings to dewater the coal slurry plaoe d in the hold even when the interstices, namely water channels, in the layer of deposited coal particles are clogged up. Accordingly the slurry can be drained within a much shorter pericd of time than is convention-ally possible.

`:, Figs. 18 to 20 show another slurry transport ship of the dewatering type.
The ship has a hold 100 shown in Fig. 18. At the four corners of a hatch cover 101 inside thereof, there are take-up rollers 103 for paying off cables 102. These rollers 103 are covered with ocvers 104 and are rotatable at the same time by unillustrated drive means. m e cables 102 ext~nding dcwnward fram the rollers 103 are attach~d at their lower ends to the four corners of a dish-shaped dewatering frame 105 including a frame member 106 in the form of a rectangular ring. A filter 107 ext~nding over the frame mEmber 106 and attached to the under side thereof is reinforoe d by a latti oe -like fra~ework 108. Metal netting, fibrous or various other m~terials are useful for the filter 107. The filter 107 is bulged downward in its oe nter. The frame member 106 formLng the side walls of the dewatering frame 105 is provided therearound with a pneumatic-ally inflatable annular buwy 109 serving as a float and communicating with air supply-discharge means (not shcwn). A draining pump 110 is disposed in the oe nter of the dewatering frame 105. The pump 110 has an outlet pipe 111 con-nected by a drain pi~e 112 to a discharge hose 113 on an upper portion of a sidewall of the hold 100.
At the loading port, the cables 102 are wound on the rollers 103 to store the dewatering frame 105 inside the hatch cover 101 as indicated in a two-dot-and-dash line in Fig. 18, and the hatch oover 101 is then remcved to cpen the hatch 114. A ooal slurry is loaded into the hold 100 through the hatch 114.
With the lapse of time, large coal particles of great specific gravity settle toform a lower layer Sl, while small ooal particles of reduced specific gravity float to form an upper layer S2. Thus the upper layer S2 contains fine coal part-icles suspended in water. The cables 102 are then paid off from the rollers 103 to lcwer the dewatering frame 105. At the same time, the buoy 109 is inflated with air, and the frame 105 is thereafter floated an the surf~oe Ll of the slurry water. With the dewatering frame 105 floating on the water surface Ll, the rollers 103 are made free to pay off the cables 102. In this state, the buoy 109 prevents the slurry water fram flowing into the d~watering frame 105 over the frame member 106. Since the dewatering frame 105 floating an the surface Ll is dish-shaped, the filter 107 is held immersed in the slurry water, pPrmitting water W alone to penetrate the filter 107 and flow into the frame 105 to separate the water from coal particles. When the draining pump 110 is subsequently oper-ated, the water W is discharged by the pump 110 through the outlet pipe 112 and hose 113. This lowers the leval of the slur~y water, allcwing the frame 105 to follow the water le~el under gravity. When the draining operation is oantinued, the upper layer S2 is almost ocmpletely dewatered as indicated in a dot-and-dash line in Fig. 18, whereby the frame 105 is plaoe d on the lower layer Sl. When the pump 110 beoomes unable to draw off any water, the cables are tah~n up an the rollers 103 to raise the frame 105 and store the frame inside the hatch oover 101.
At the same time, ~;r is released from the bu~y 109 to oontract the buay.
Although the single dewatering frame 105 is used for the hold 100 as described ab~ve, the slurry in a single hold 115 can be dewatered with use of a plurality of dewatering frames 116 as shown in Fig. 20, which shows frame members 118, buoys 119, draining pumps 120, cables 121, rollers 122, a hatch caver 123 and an upper deck 124.
While the dewatering frame in the foregoing e~bxxLument is suspended from the hatch oover or upper deck, a separate support is alternatively usable for suspending the dewatering frame. The term "dish-shaped" used for describing the dewatering frame refers generally to those in which the peripheral portion is higher than the oenter portion. ~hus the dewatering frame, for example, may have a recessed aenter portian.

With the transport ship shcwn in Figs. 18 to 20 in which the slurry is dewatered always in the vicinity of the surfa oe of the slurry water, the reduc-tion in draining efficiency due to the clogging of the filter can be minimized.
Further the dewatering frame, which is kept floating on the surface of the slurry water at all times by a float, is caused by gravity to follow the des oe nt of water level due to draining, so that the apparatus is operable without necessitat-ing additional equiFment and is also easy to handle.
Figs. 21 to 27 show another slurry transport ship of the dewatering type.
The ship has a hold 234 provided in its bottom with drain openings hav-ing a filter (not shcwn). Rotary shafts 237 each carrying a turning arm 236 at its lower end extend from the top wall 235 of the hold 234. The rotary shafts 237 are disposed, for example, at the four corner portions of a hatch 238, such that the entire area of the hold 234 can be covered with the paths of rotation of the turning arms 236 to the greatest possible extent as seen in a plan view (Fig.
22).
m e turning arm 236 oo~prises a plurality of segments 236a of box-shaped cross section which are joined together with one fitted in another. The segments 236a are connected to one another by pins 239 and are slightly pivotally movable upward and downward relative to one another but are not laterally thereof at the connected portions. The turning arm 236 is provided on its under side with a large nu~ber of stirring blades 240 which are arranged at suitable spacing longitudinally thereof. The stirring blades 240 may be inclined with respect to the lengthwise direction of the arm 236 as seen in Fig. 26, or may be perpendic-ular to the lengthwise direction. A conical projection 241 extends from the lower end of the rotary shaft 237.
The rotary shaft 237 has a hollow upper portion which is inserted in a 9 ~i3 rotation transmitting tubP 242 rotatably supported on the top ~all 235 of the hold 234 and which has a screw m d 243 extending thereinto. The screw rod 243 isrotatably supported by a support member 244 Qn the top wall of the tube 242 and is screwed into a threaded m~mber 245 within the rokary shat 237. m us the shaft 237 is suspended from the screw rod 243. The screw rod 243 is coupled to aportable air motor or like drive means. The drive means, screw rcd 243, support member 244 and threaded member 245 constitute means 246 for vertically moving the rotary shaft 237.
Projections 247 and 248 meshing with each other are provided respect-ively on the inner surfaoe of the rotation transmitting tube 242 and on the outer surfa oe of the rotary shaft 237. A gear 249 is externally formed on the lower end of the tube 242 and is in mesh with a drive pinion 250 coupled to an air mDtor or dri~e means. The drive means, drive pinion 250, gear 249, tube 242 and projections 247, 248 prcvide means 251 for rokating the shaft 237. Indicated at 252 is a member for su~porting the drive pinion 250.
The above arrangement operates in the following m~nner. While not in use, the turnlng arm 236 is pulled up to and stored inside of the top wall of the hold, i.e., on the rear side of the upper deck inside the hatoh coaming, with the shaft 237 retracted in the tube 242 as oDcn in Fig. 23. When the turning arm is to be used, the screw rcd 243 is rotated to lcwer the rokary shaft 237, causing the lower end projection 241 of the shaft 237 to penetrate a shell-like layer formed in the top portion of the slurry within the hold 234. $he arm 236 is turned by the shaft 237 through the tube 242 to break down the shell-like top layer of the slurry with the stirring blades 240. At this time, the rotary shaft237 is held stably to smoothly turn the arm 236, by being supported at its upperend and also by the shell-like layer pieroe d with its lower end projection 241.Sin oe the arm 236 comprises the segments 236a which are connected to one ancther ~ ~iO~`.;B

upwardly and downwardly movably as described above, the arm 236 is flexible in oonformity with the config~ration of the upper surface of the shell-like layer, with the result that the arm is turnable smDothly without any trouble. Torque can be transmitted from the tube 242 to the shaft 237 irrespeotive of the level of the shaft 237 because the projections 247 and 248 are used for transmission.
When the shell-like }ayer is broken at the top portion of the slurry, air flows into the slurry smcothly, whereby the water component of the slurry is smDothly remDvable fram the bottam of the hold 234.
The turm ng arm 236 may be provided at a oorner of the hold 234 as in-dicated at 236' in Fig. 22 so as to turn reciprocatingly over an angle of 90 de-grees, or may be provided close to a side wall of the hold 234 as indicated at 236" in Fig. 22 so as to turn reciprocatingly over an angle of 180 degrees.
Further as shown in Fig. 27, the turning arm 236 may be in the form of an integral member attached to the lower end of the rotary shaft 237 slightly turnably upward and downward. A large number of turning arms 236 may be attached to the rotary shaft 237 as arranged radially.
With the transport ship shcwn in Figs. 21 to 27, the turning arm having stirring blades and attached to a vertically movable rotary shaft, when turned, easily breaks up the shell-like layer of fine particles in the top portion of slurry, permitting ulL~ i3d flow of air into th~e slurry to assure smooth remDval of water fram the slurry via the bottom of the hold. The arm is smcothly turn-able with stability sinoe the lcwer end conical projection piercing the shell-like layer serves as a support for the arm.
Figs. 28 to 33 show anokher coal slur~y transport ship having an agitator by which the coarse particle coal held in its hold and dewatered during navigation is made into a slurry again at a port of delivery.
The ship has a hold 125 of double bottom construction 126. A slurry g`~J~

outlet 127 formed in the center of the inner bottom plate 132 is in aommunicationwith a discharge pump 129 via a valve 128. A slurry outlet duct 130 is aonnected to the pump 129. A screw aonveyor 131 extends from each of the four bottom aorner~ of the hold 125 to the slurry outlet 127. The screw aonveyor 131 can be mounted on the inner bottom plate 132 with bearings, but in the present embcdi-ment, the lower half of the conveyor 131 is acoomm~dated in a channel of semi-circular cross section formed in the bottcm plate 132. The screw conveyor 131 is aoupled at its base end to drive means 135 by way of trar~Lmitting means 134. m e aonveyor has a blade 131a and a water pipe 136 extending along the helical outer periphery of the blade. The base portion of the water pipe 136 is fitted in the base end (see Fig. 31) or the forward end (see Fig. 29) of the aonveyor 131 and aonnected to a condu1t 138 by a rokary joint 137. The helical portion of the water pipe 136 is provided with jet nozzles 141 at specified spacing.
When a mass of coal particles dewatered to some extent during naviga-tion is to be made into a slurry again at the port of delivery, the screw aon-veyors 131 are driven, with water for oe d into the water pipes 136 to inject the water into the mass throuyh the jet nozzles 141. The water may be supplied from a suitable Jocation on the land or the like. While thus being agitated effect-ively, the aoal particles are made into a slurry again and led into the slulry outlet 127.
In plaae of the water pipe 136 and jet nozzles 141, a multiplicity of jet nozzles 144 may be provided on the rotary shaft portion 143 of a screw aon-veyor 142 to force out water fm m between the adja oe nt portions of a blade 142a as seen in Figs. 32 and 33. Alternatively the nozzles 144 may be used in comr bination with the nozzles 141. With referen oe to Fig. 33, the jet nozzles 144 are implanted in the shaft portion 143 bet~een the adjaaent portions of the blade 142a. The forward end faoe 144a of the jet nozzle 144 is flush with the cuter ~o9`~

periphery 143a of the shaft portion 143. The orifice 145 of the nozzle communi-cates through a passage 147 with a fluid supply channel 146 fo med in the shaft portial 143 along its axis. The jet nozzles 144 are arranged ~n a helical phantan line on the outer periphery of the shaft portion 143. Indicated at 148 is means for driving the screw canveyor, at 149 a bearing, and at 150 a rotary joint having an internal passage 151 for holding unillustrated liquid supply means in ccmmunication with the fluid supply channel 146.
With the transport ship shown in~Figs. 28 to 33, the aoal slurry can be discharged f m n its h~ld rapidly for unloading. Especially when the jet nozzles are adapted to discharge water in a suitable direction, the reaction of the dis-charge can be utilized for supplementing the pcwer needed for the rotation of the screw aonveyor.
Fig. 34 is a flow chart showing another method of the inv~ntion.
Fig. 34 is similar to Fig. 1 in that the ooal pulverized by a coal mill 153 at a ooal mLning area 152 is fed to an apparatus 154 for preparing a slurry, which is transported to a lo~ding port through a pipeline. At the loading port, the coal slurry is temporarily stored in a slurry pand 155 (see Fig. 35). The slurry is th~n led through a supply duct 156 into the upper end of a first liquid cyclone 157, in which the slurry is wet classified into a fraction of aoarse part-icles, for example, larger than 0.15 mm in size and a fraction of fine particles.Tb assure wet classifiaation effectively, the latter fraction from the first liquid cyclone 157 is fed to a second liquid cyclone 158 disposed alongside the cyclone 157, whereby the fraction is further subjected to wet classification.
Thus the first and seco,nd liquid cyclones 157 and 158 canstitute a slurry sepa-rator 159. The aoal slurry thus obtained and oontaining ooarse particles of larger than 0.15 mm is led through ducts 160 and 161 into a pond 162 for storage.
As is the case with Fig. 1, the coarse particle slurry is loaded into a transport ship 163.

~o9`~

on the other hand, the fine particle coal slurry containing particles of up to 0.15 mm and separated from the coarse particle slurry is sent through a duct 164 to a thickener 165, in which the slurry is thickened by settling. The thickened fine particle slurry is run off fr~m the bottom of the thickener 165 and fed to a pri~ary granulating tank 168 of a two-stage granulating apparatus 167 via a duct 166. m e supernatant in the thickener 165 is discharged via an overflow trough 169. Fuel oil or like binder is then introduced into the primary granulating tank 168 through a duct 170. m e fine particle slurry and the binder are mixed together by being vigorously agitated by a homDgenizer or like agitator.
m e mixture is introduoe d into a seoondary granulating tank 171, in which it is gently agitated, for exa~ple, by a devi oe (not shown) having agitating blades of metal net to form the fine particles into granules. Since ooal and oil generally have affinity for each other, fine ooal particles are joined together with fuel oil or like binAPr adhering to the surfa oe s of the particles for granulation.
Examples of useful binders are fuel oil, ker~sene, gas oil, residuum oil and vegetable oils. m e slurry containing the granules is introduced into the upper end of a third liquid cyclone 173 through a duct 172, whereby the gran~ s are sep æ ated f m m the liquid by wet classification. m e granules are sent to a storage pand 175 through a duct 174 and loaded into a transport ship 176. The granules may be sent to the storage pond 162 and loaded into the ship for trans-porting the ooarse particle slurry. The ooarse particle slurry and granules may be dewatered after loading. m e liquid drawn off f m m the top of the cyclone 173 is predbminantly water, but if the liquid ocntains a small an~unt of ungranulated fine coal particles, the liquid is returned to the granulating apparatus 167 via a duct 177 to oompletely reoover the fine particles in the fonm of granules.
With the methcd shown in Figs. 34 and 35, a ooarse particle fraction is separated from a slurry of particulate ooal by wet classificatian, a binder is ~Q~3'~'8 then added to the remaining portion of the slurry containing fine particles to granulate the fine particles, and the grains or granules are then separated fram the liquid for the reoovery of coal from the slurry, so that only tha fine part-icles Ln the slurry nead to ba granulatad. Consequently ooal can ba recovered fram the slurry very efficiently by treating a smaller amcunt of particles with a smaller amDunt of bindar for a shorter pariod of t~me than when tha particles in tha slurry are all granulated. Mbreover, the coal recovered, which comprises granules and ooarse particles having larga sizes, is highly pPrmaable to water and easy to drain. This greatly facilitates the dewatering, drying and other procedures to ba followad for the coal recovered, consequently assuring efficient reco~ary of particulate coal f m ~ tha slurry. Granulatian of fina coal particles further serves to remDve ash fram the coal. Mbre spacifically stated, the rn~l slurry oontains fina particles of ash (inorganic substan oe s) prcduced by the pulverizatian of ooal and having no æ finity for fuel oil or like bindar. Accord-ingly during the granulatiQn of fine coal particles, the ash d oe s not adhere to the bit~der but is separated fr~., the granules of fine coal particles, whereby the ash can be remDved fram the coal recovered.
Fig. 36 is a flow chart showing another mathod of tha inventian.
With referen oe to Fig. 36, coal is pulverized by a ooal mill 181 at a ooal mining area 18~. The coal is pulverized to a maxImum size, for example, of abcut 3 mm. Uhtil a slurry of fine ooal particles is returned from the loading port as will be describPd later, the ooal is finely divided to obtain fine ooal particles of up to 0.075 mm in size. m e pulverized coal is fed to a slurry pre-paring apparatus 182 along with water to obtain a slurry. me particle size dis-tribution of the slurry is so adjusted that about 20% by weight of all the ooal particles are fine particles of the abave-msntiQned size. m e coal slurry is oonveyed through a pipeline to a loaling port, where the slurry is fed to a slurry separator 183 and thereby separated into a slurry of fine aoal particles up to 0.075 mm in size and a slurry of coars~ coal particles 0.075 to 3 mm in size.
The aoarse particle aoal slurry is stored In a storage po,nd 184 and th~n loaded into a transport ship 185 as is the case with Fig. 1.
On the okher hand, the fine particle coal slurry is returned as it is to the coal mining area thr~ugh a pipeline. This slurry and coarsely divided aoal 0.075 to 3 mm in particle size are fed to the slurry preparing apparatus 182 to prepare a slurry in which abcut 20~ by weight of the aoal particles are fine particles, like the one already prcdu oe d. The slurry is conveyed to the lca~ng port through the pipeline. After the fine particle ooal slurry has ba~n returned to the ooal mining area, there is no need to finely divide the coal to particle sizes of up to 0.075 mm, but the coal mill 181 needs to give only aoarsely divided aoal of 0.075 to 3 mm in p æ ticle size. Thus with use of the aoæ sely divided aoal and the returned fine particle aoal slurry, a slurry is pre-pared which has the desired particle size distribution and which can be continu-ously transported by the pipeline with a relatively small pcwer.
The particle size of 0.075 mm is adc~3d as the separation standard for the following reasons. For the reduction of the transport aost, the coal ZO slurry m~st have inaorporated therein finely divided aoal, up to 0.075 mm in size, which, however, is costly to prepare at the aoal mining area. Mbreover, slurries aontaining such fine aoal particles are very difficult to dewater. When a slurry of large aoal particles is aonveyed through a pipeline, the slurry is easy to de-water after transport but causes marked we æ on the pipe and requires a rela-tively high flow velocity, aansequently ne oe ssitating increased power aonsumption :
and entailing a higher transport aost. For this reason, it is practi oe to aonvey a slurry which CQntains both l æ ge aoal particles and fine ao~l p æ ticles, such .

that the aoal particles are about 2 to about 3 mm in maxiDJIm size and about 0.1 to about 0.4 mm in average size and include fine particles of up to 0.075 mm in an an~unt of about 20% by weight. Such slurry is less likely to wear the pipe and can be transported at a redu oe d velocity and therefore at a lower cost but is difficult to dewater after transport sin oe it contains fine coal particles.
Additionally aoal must be finely divided to obtain fine particles for the prepara-tian of the slurry at the coal mining area.
With the methcd illustrated in Fig. 36, hc~ever, the fine particle coal slurry separated at the loading port is returned as such to the aoal mlning area through a pipeline, so that the remaining coarse particle aoal slurry is easy to dewater. Mbreover, sin oe the fine particle slurry returned to the mining area is reused for the preparatian of a ooal slurry at the mining area, the slurry can be ocnveyed less expensively due to the presen oe of the fine particles. Additian-ally there is substantially no ne oe ssity for fine pulverization to obtain fine particles needed for reduaing the transport cost. Accordingly the slurry can be prepared, conveyed through the pipeline and dewatered at reduced costs.
Fig. 37 is a flow chart showing another method of this inventian.
Fig. 37 is similar to Fig. 1 in that the aoal pulverized by a aoal mill 187 at a coal mining area 186 is fed to a slurry preparing apparatus 188 to ob-20 ~;n a coal slurry, which is aonveyed to a loading port through a pipeline. Atthe loading port, the ooal slurry is temporarily stored in a storage pond 189 and then loaded into a transport ship 190 as such.
As seen in Figs. 38 to 42~ the ship 190 has a number of holds 193 arranged longitudinally thereof and defined by lateral partitions 191 and opposed side walls 192. A large number of slurry outlets (openings) 194~ which are clos-able, are formed in an upper portion of the lateral partition 191 of each hold 193. A slurry withdrawing opening 197 ocmmunicating with a slurry discharge duct ~09~Y~

196 is disposed outside a lower slanting portion 195 of the partition 191. The discharge duct 196 extends through the interior of a bottom wall 198 of double aonstruction to a slurry storage pond 199 on the shore and has a pump 200. A
large r~mber of dewatering filters 201 is provided at the lower end of the lateral partition 191. A water aollecting bilge well 202 is disposed inside the bottcm wall 198 at its one end. A water withdrawing opening 203 inside the bilgewell 202 communicates with a drain pipe 204 extending outward from the ship.
The slurry S serlt forward frcm the storage pond 189 is charged into the hold 193 as shown in Fig. 39 and is allowed to stand for a specified period of time. Ccn~xYioently the slurry S separates into two layers, nan~oly a coarse part-icle lower layer Sl and a fine particle upper layer S2, as seen in Fig. 40. Whenthe slurry outlets 194 are then opened, the upper layer S2, namely the fine part-icle coal slurry, flows out from the hold 193 through the outlets 194, descends the outer sidb of the lateral partition 191 and is collected under the lower slanting portion 195 of tho partition outside thereof. The fine particle slurry is then returned to the storage pond 199 on the shore via the disch æ ge d w t 196.
As a result, the lower layer Sl only remains within the hold 193 as seen in Fig.41. During navigation, the lower layer Sl, namely the aoarse particle c~al slurry, is drained by the dewatering filters 201. The water is aollected in the bilge well 202 and run off fm m the ship via the drain pipe 204.
The fine particle coal slurry returned to the pond 199 may be aoncen-trated for solidification as seen in Fig. 1, or granulated as shown in Fig. 34, or returned to the cDal mining area in the form of a slurry as seen in Fig. 36.
Fig. 43 shows a transport ship slightly different from the one des-cribed above.
With referen oe to Fig. 43, a hold 205 for fine particle slurry is posi-tioned in the center of a longitudinal arrangement of many holds 193. A slurry ~ 09'78 discharge duct 196 is connected via a pump 200 to a slurry duct 206 extending over the upper deck into the fine particle ccal slurry hold 205. With the excep-tion of the above feature, the ship is similar to the one shcwn in Figs. 38 to 42.
With the present enblxlment, the coal slurry conveyed through a pipe-line is placed into the holds 193. As is the case with the preceding entxxL~nent, fine particle ooal slurry is collected under the lower slanting portion 195 of each hold 193 outside thereof, with ooarse particle ooal slurry remaining in the hold 193. The fine particle slurry is sent into the hold 205 via the duct 206 by the pump 200. The fine particle slurry is discharged as such at the port of de-livery by a pump.
Figs. 44 to 52 show another ~cdified transport ship.
With referen oe to Fig. 44, the ship has a number of holds 208 dividedby lateral partitions 207. As seen in Fig. 45, a large numker of c~rflow open-ings 209 are formed in an upper portion of the lateral partition 207 of the hold 208. The openings 209 are provided with an unillus*rated mLvable dbor for verti-cally a~justing the pOSitiQn of the lower edges defining the openings 209. A
slurry withdrawing opening 212 ocnmunicating with a slurry transfer duct 211 is disposed outside a slanting lower portion 210 of the partition 207. The transfer duct 211 thus ocmmwnicating with all the withdrawing openings 212 extends through the interior of a bottom wall of dDuble construc*ion tD a pump 214, from which the duct 211 further extends to separators 213 above the holds 208. The portion of the duct 211 extending f m m the pump 214 to the separators partly serves as a granulating tube for nixing a fine particle ooal slurry and a binder together by stirring and forwarcing the mixture as shcwn in Figs. 48 and 49. Mbre specific-allyl a rcd 215 in alignment with the axis of the transfer duct 211 is pr w ided in a short straight portion 211a of the duct 211. One end of the r~d 215 is rotatably and liquid-tightly supported by an outer corner portion 21Ib of the 09'`78 straight portion 211a at its one end. The other end of the rod 215 rotatably andliquid tightly extends through an outer oorner portion 211c of the straight por-tion 211a at the other end thereof and is connected to unillustrated drive means.
m e rod 215 is provided at some locations with stirring blades 216 of metal nett-ing, with a clearan oe a formed between the outer periphery of the blade 216 and the inner surface of the duct 211. The transfer duct 211 has a binder inlet (not shown) at a suitable portion.
As shown in Figs. 46 and 47, each of the separators 213 comprises a m~in body 218 in the form of an elongated box and movably extending across a hatch coaming 217, and a filter 219 extending over the entire inner area of the main body 218 and positioned at an intermediate portion of its height. The main body 218 has a slurry inlet 220 at its one end on the upper side of the filter 219 and a water outlet 221 at the other end thereof on the under side of the filter 219. m e filter 219 is so inclined that it is at a higher level toward the slurry inlet 220. m e filter 219 has in its oe nter a ooal inlet tube extend-ing through the bottom wall of the main body 218 and opened to the hold 208. The slurry inlet 220 of the separator 213 is connected to the slurry transfer duct 211 by a flexible tube 223. m e water outlet 221 of the separator 213 is con-nected by a flexible tube 224 to a drain pipe 225 one end of which extends to the land. The transport ship further has a slurry loading duct 226 extending from a slurry storage pond on the shore to upper portions of the holds 208.
A slurry of particulate ooal is supplied fm m the storage pond on the shore to the holds 208 thrDugh the loading duct 226. While thus loading the slurry, the o~erflow openings 209 are op2ned to a suitable degree to cause super-natant water containing fine ooal particles to o~erflow the lateral partitions 207 through the openings 209. The water outside the partitions is led into the withdrawing openings 212 into the transfer duct 211 by the pump 214. While the ~Q~

fine particle coal slurry is being passed through the duct 211 to the separat~rs213, a binder comprising fuel oil or the like is admixed with the slurry by stirr-ing in the granulating tube to granulate the fine particles in the slurry. M~re specifically fine co 1 particles in the slurry flowing through the duct 211 and the binder are mLxed together by being stirred with the blades 216, whereby finecoal particles are adhered to relatively large coal particles to form agglomer-ates, namely grains or granules. The m~vement of fine coal particles at this time is indicated by an arrow in Fig. 49. This ~ovement is different from that heretofore observed in a static mLxer in which the duct is provided with only bladelike blocking plates or in a line mLxer comprising an agitator having ~sualblades. Thus the movement of ooal granules and fine coal particles within the duct 211 or the rolling motion thereof an the &ct wall serves effectively for the progress of granulatian. The coal granules formed in the straight portion 211a of the &ct 211 flow downstream through the cle æ ance a. Further coal granules formed earlier rapidly fall bPtween the stirring blades 216, permittingother fine coal particles to foLm granules smLothly. With fine coal particles thus granulated, the slurry is plaoe d onto the filter 219 of the se~arator 213 through the inlet 220. The slurry oantaining the granules flows dç~n th~e filter219, while permitting ash-ccD~G~ining water to pass through the filter 219 to the lower portion of the main body 218 and flow out through the water outlet 221.
on the other hand, the granules of large size rerain on the filter 219 and pass through the inlet tube 222 into the hold 208. The sep æ ator 213 is reciprocatedan the hatch ooaming 217 at a relatively low speed langitudinally of the ship.
The slurry fed to the sep æ ator 213 oonta ms granules of large size only and istherefore easy to dewater and sep æ ate. The water run off fnom the wat~er cutlet 221 is sent through the drain pipe 225 to suitable means on the shore, whereby the ash is rcmDved from the water. The water is then led to a pond on the shore and reused as slurry water.

g`,~8 Although the granules of fine coal particles are added to the coal slurry separated from fine coal particles in the above en~xILu~ent, the granules can be placed into a separate hold.
As seen in Figs. 50 and 51, the granulating tube included in the slurry transfer duct may comprise bent duct portions 227 prcvided in an intermediate part of the transfer duct 211 and each including stirring bla~es 228, the bent duct portions being provided in a plurality of stages. Each of the b~nt duct por-tions 227 comprises a horizontal tube 227a and a bent tube 227b extending obliquely upward from the horizontal tube 227a and having a closed end 227c. A
rod 229 dispo æ d in the bent tube 227b and having stirring blades 228 r~otatably extends through the closed end 227c and is connected to an unillustrated drive means. The junction 230 betwa~n the horizontal tube 227a and the bent tube 227b is oonnected to one end of the horizontal tube 227a of another bent duct portion 227. Thus the bent duct portians 227 æe joined to one another in stag~es.
m e coal slurry in the bent duct portions 227 mcves as indicated by æ rows and is effectively mixed with the binder, whereby the coal can be granu-lated efficiently.
Alternatively the stirring means may cowpri æ a rod 232, stirring blades 231 mounted on the rod, and radial blades 233 attached to each s;~ of the blade 231 as seen in Fig. 52.
Figs. 53 to 56 show anokher slurry transport ship having coal slurry separating means.
m e ship has holds 253 æ ranged longitudinally thRreof for containing a ooal slurry and empty cha~bers 254 between the holds 253. Drain openings 256 formed in an upper portion of the re æ wall 255 of the hold 253 are in oommunica-tion with t~e empty chamber 254. m e drain opening 256 may be in the form of a cutout or an aperture. A drain channel 257 is provided at the bottom of the .

~`- .

~0~`~`8 empty chamber 254. m e hold 253 is provided at its kottom with bottom drain open-ings 258 aommunicating with the empty chamber 254. A fine particle coal slurry withdrawing duct 259 is disposed at the bottom of the em,pty chamber 254.
Two nozzle mounting pipes 261 are positioned some distan oe below the top wall of the hold 253 and extend along opposite side edges of a hatch 260.
Each of the mounting pipes 261 has a multiplicity of injection nozzles 262 arranged longitudinally thereof at suitable spacing. ane end of t~e pipe 261 is acnnected by a water supply conduit 264 to a pump 263 for supplying high-pressure jet water. Pressurized air or like high-pressure fluid is usable in plaae of water. The nozzle mounting pipe 261 is rotatably supported at its opposibe ends by support menbers 266 attached to the top wall 265 of the hold 253 and is pro-vided with means 267 for adjusting the angle of turn thereof. m e angle adjust-ing means 267 acmprises a lever 268 fixed to the pipe 261 and a screw rnd 269 rotatably aonnected at its one end to the lever and in screw-thread engagement with a threaded member 270 on the top wall 265 of the hoJd 253. m e screw rod 269, when turned by a handle 298, turns the injection nozzles 262 to a substant-ially horizontal position or to an obliq~ely upward positian as seen in Fig. 56.
Preferably the nozzles 262 on the pipe 261 are made turnable toward the front or rear by some means. However, the injection nozzles 262 may he fixed as inclined toward the drain cpenLngs 256.
With the arrangement described akove, the supernatant water of the aoal slurry in the h~ld is discharged fr~- the drain o~enings 256 into the ~IyLy ch~rber 254. The fine particles floating in the uFper layer of the slurry can also be discharged in the follcwing manner. Water is injected into the upper layer of the aoal slurry (i.e. about 1/5 portion of the height of the load) from the nozzles 262 in horizontal position to agitate the layer. The injection nozzles 262 are then turned obliquely upward toward the drain openings 256 to 13,~09'78 for oe the floating fine p æ ticles tow æ d the openings 256 with the injected water and discharge them into the empty chamber 254. The fine particulate coal can be discharged even when the injection nozzles 262 are fixedly directed tow æ d the drain openings 256. Sin oe the fine coal p æ ticles are thus remaved from the upper layer of the slurry, no covering will be formed with fine particles, per-mitting ~;r to pass through the slurry effectively and enabling water to flow out smDcthly from the bottom drain openings 258 of the hold 253.
With the transport ship shown in Figs. 53 to 56, the supernatant water ~ ,taLning fine coal particles in the top layer of the slurry is discharged by jets of fluid, so that the slurry can be separated efficiently without permitting fonmation of a covering layer of fine coal particles that would inpede remDval of water through the bottom drain openings of the hold.
Figs. 57 to 61 show another slurry transport ship.
Guide rails 272a and 272b are provided on an opposed pair of side walls of the hatch ooaming 271 of a hold 253. A flap 273 is provlded between and sup-ported by the guide rails. The flap 273 carries rollers 274 in engagement with the rails 272a, 272b and reinforcing members 275. The flap 273 has such a lengththat it reaches the upper layer of the coal slurry to be loaded into the hold 253.
Means 276 for driving the flap 273 oo~prises a pair of endless steel cables 277a, 277b reeved around pulleys 278 and turnable along the rails 272a, 272b and a mDtor 279 for driving the pulleys 278. m e flap 273 is attached to the cables 277a, 277b. With the exception of the above feature, the ship is similar to the ane shown in Fig. 53.
With this arrangement, the mDtor 279, when driven, reversibly turns the steel cables 277a, 277b, moving the flap 273 back and forth within the hold 253 along the guide rails 272a, 272b, whereby the fine particle ooal slurry in the top portion of the ooal slurry in the hold 253 can be discharged into the empty ..
.

~ ~09'~8 chamber 254 through the drain openings 256. This prevents formation of a cover-ing layer of fine coal particles, permitting water and air to pass through the slurry effectively and allowing water to flow out smLokhly fram the ~ott~m drain openin~s 258 of the hold 253.
Thus the transport ship shawn in Figs. 57 to 61 has the simple construc-tian that a flap for discharging fine particle coal slurry is maunted on guide rails on a hatch coam m g, whereby fine particle coal slurry can be separated off and rem~ved smDothly f.~.. the upper layer of a ooal slurry, and water can be dis-charged from the bottom of the hold efficiently because of an urun~aded flow of air through the slurry.
Figs. 62 to 64 shaws another slurry transport ship.
A hold 280 has thereabove a hatch 282 defined by a hatch coaming 281 and closable ky an unillustrated hatch oover. A spa oe 284 for accammDdating supernatant is provided bPtwe~n lateral partitions 283. The water acsxl~n~dating space 284 is provided at its lower portion with a drain channel 286 communicating with the interior of the hold 280 through dewatering filters 285. A bilge well 287 in communicati~n with the drain channel 286 is provided in the bottam of double canstruction of the hold 280. A tray 289 in the form of an angle in cross section extends along the entire inner peripheral surfaoe of the hold 280, i.e.
along the front and rear lateral partitions 283 and opposite longitudinal parti-tions 288. The lateral partitian 283 is formed with apenings 290 for holding the interior of the tray 289 in communication with the spaoe 284. A bell-mDuth 291 for discharging supernatant water is disposed at a lower portion of the spaoe 284.
A branch duct 294 of a slurry duct 293 on an upper deck 292 has a forward end (not shown) extending through the lateral partition 283 into the hold 280. Indic-ated at 295 is the lawer settling layer (coarse particle ooal slurry) of a slurry, and at 296 the supernatant water (fine particle coal slurry) of the slurry.

~9~

The coal slurry is charged into the hold 280 through the duct 293 and branch & ~t 294. Upon the water level reaching the uppar end of the tray 289, the supe m atant water 296 overflows the tray over the entire interior area of the hold 280, flows through the tray 289 and falls into the spa oe 284 through the openings 290.
When loading in rough weather, pitching or rolling of the ship will raise the level of the suparnatant water above the uppar end of the tray 289, causing a large amDunt of the water 296 to abruptly flow into the tray. To pre-vent this, the tray shown in Fig. 64 has an ext~nsion higher than the usual height of tray and in the form of a porous filter 297. When the supernatant water renains at a normal level A, the water flows out near the lower end of the filter 297, whereas if the water rises to an a~normal level B due to pitching or rolling, the water flows cut over a considerably large area of the filter 297.
With the transport ship of Figs, 62 to 64 which is adapted to separate supernatant water containing fine particles (i.e. fine particle ooal slurry) fram a coal slurry while the slurry is being loaded into the hold, the supernatant water flows into the tray cver the entire periphery of the hold and then falls into t~e water acocmmDdating spaoe through drain openings. The supernatant water therefore flows into the tray gently without entraLning ooarse particles that will settle for separation. m us the ooal slurry can be separated prDperly.
Fig. 65 shows another transport ship for practicing another method of the invention.
The transport ship 300 having a number of holds which are dbfined by longitudinal partitions and lateral partitions and each of which is provided thereaboNe with a separator 213 of the same canstruction as those shown in Figs.
44, 46 and 47. The separator 213 has a slurry inlet 220 oonnected by a flexible tube to a slurry loading duct 301, one end of which is oonnected to a slurry stor-.' ~t~9 ~8 age pond 302 on the shore. The loading duct 301 has a binder inlet at a portion thereof close to the pond 302. As is the case with Figs. 48 to 52, the duct 301 has inoorporated therein granulating means oomprising stirring blades for mixing a slurry and a binder together by stirring. The separator 213 has a water outlet 221 connected by a flexible tube to a drain pipe 303, one end of which is con-nected to an ash remDving apparatus 304 on the shore. The ash removing apparatus 304 has a water outlet 305 connected to the pond 302 and an ash outlet 306 con-nected to a press filter 307.
With the above arrangement, a coal slurry is supplied from the pond 302 through the loading duct 301, while a binder is added to the slurry through the binder inlet of the duct 301. m e slurry and the binder are mixed together by stirring and sent toward the separators 213 while coal particles are being granu-lated. The slurry oontaining the granules is fed to the apparatus 213 through the inlet 220. As in the erlxXl~nent already described, the granules of l~rge size are sep æ ated from ash-ccntaining water and placed into the hold. The ash-oon~;n;ng water is disch æ ged through the water cutlet 221 and sent through the drain pipe 303 to the ash removing apparatus 304, in which the ash is removed from water by ccnL~sd~ation. m e water alone is sent to the pond 302 and used again for the preparation of slurry. The cancentrated ash is further sent to the press filter 307 and dewatered.
Although fine particles are granulated while loading the ooal slurry into the ship in the above emiKxlment, the coal slurry may be subjected to granu-lation by an apparatus on the shore near the loading port as seen in Fig. 66 and thereafter loaded into a ship.
With referen oe to Fig. 66, a granulating and classifying apparatus 310 granulates ooal particles and classifies the granules. The apparatus 310 in-cludes a granulating devi oe 311 for admixing the binder supplied from a binder ~0~'78 cantc~iner 312 with a ooal slurry by stirr m g for granulatian. A vibrating scre~n 313 classifies the granules fram the devi oe 311 into three different particle sizes. The ~r~rse granules and scmewhat smaller granules separated by the first and second stages of the screen 313 are dewatered by rctary screens 314 and 315 respectively and are further stored in tanks 316 and 317 resFectively. The water separated is sent to a water tank (not shown). The granules in the form of fine particles and separated by the third stage of the vibrating screen 313 c~re sub-jected to wet classification by a wet cyclone 318. The relatively coarse granules separated are dewatered by a rDtary scre~n 319 and stored in a tank 320.
The relatively fine granules separated are dewatered by a rokary screen 321 and stored in a tank 322. The water separated off by the rotary scr3~ns 319 and 321 is sent to the water tank.
The ccal separated from ash-oontaining water in this way is loaded into a transp~rt ship as it is or as made into a slurry again with addition of water.

Claims (16)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A method of transporting coal comprising slurrying pulverized coal at a coal mining area and transporting the coal slurry through a pipeline to a loading port, classifying this slurry at the loading port in accordance with coal particle size into a fine slurry fraction containing fine particles of a size not larger than the specified one and a coarse slurry fraction excluding such fine particles, transporting the coarse slurry fraction by ship while returning at least a portion of the fine slurry fraction through a pipeline to the coal mining area, admix-ing the returned fine slurry fraction with newly pulverized coal particles to make a slurry, and transporting this slurry through the pipeline to the loading port.

2. A method as defined in claim 1 wherein the classifying is performed by equipment on the shore at a loading port.

3. A method as defined in claim 2 wherein the coal slurry is classified by an agitation tank provided at its bottom with agitating blades for upwardly directing the contents of the tank.

4. A method as defined in claim 2 wherein the coal slurry is classified in a plurality of classifying basins arranged side-by-side by introducing the coal slurry into an upstream classifying basin and causing the slurry to flow downstream from basin to basin over partitions between the basins.

5. A method as defined in claim 2 wherein the fine slurry fraction is removed from the coal slurry by passing the coal slurry through a slurry conveying and dewatering tray comprising an upper tray member, and a lower tray member disposed below the upper tray member and spaced apart therefrom by a specified distance, at least one of the bottom wall and side walls of the upper tray member being provided with a filter and a multiplicity of drain apertures for discharging water containing the fine particles.

6. A method as defined in claim 1 wherein said coal slurry from the pipeline is loaded directly into a ship, and supernatant water containing the fine particles is separated from the slurry within the ship's hold.

7. A method as defined in claim 6 wherein the supernatant water containing the fine particles is caused to flow out from openings formed at an upper portion of the hold.

8. A method as defined in claim 7 wherein the supernatant water containing the fine particles is forcibly moved toward the openings.

9. A method as defined in claim 8 wherein the supernatant water is moved by a high-pressure fluid injected into the water.

10. A method as defined in claim 8 wherein the supernatant water is moved by a flap movably mounted on a hatch coaming.

11. A method as defined in claim 2 wherein a portion of said fine slurry fraction separated from the coal slurry is loaded into the ship in the form of a slurry.

12. A method as defined in claim 11 wherein said portion of the fine slurry fraction is loaded into the ship in a hold thereof separate from the hold loaded with the slurry containing coarse particles.

13. A method as defined in claim 1 wherein a portion of the fine slurry fraction obtained by the classification is solidified by concentration, and the solidified coal is transported by a ship.

14. A method as defined in claim 13 wherein said portion of the fine slurry fraction is concentrated for solidification by being caused to flow down a slanting surface in circulation.

15. A method as defined in claim 1 wherein a binder compris-ing an oil is admixed with a portion of the fine slurry fraction to form granules, and the granules are transported by a ship.

16. A method as defined in claim 15 wherein the granules are transported in the same hold as the coal from said coarse slurry fraction.