US1940488A - Sand dredging apparatus - Google Patents

Description

Dec. 19, 1933. E. J. CROWELLS S AND DREDGING APPARATUS Filed Dec. 17, 1930 3 Sheets-Sheet 1 INVENTOR Edward J. Cram/e215.

ORNEYS.

Dec. 19, 1933. E, J. CROWELLS SAND DREDGING APPARATUS 3 Sheets-Sheet 2 Filed Dec. 17, 1930 INVENTOR Edward J' Crawells.

, lwx (v /M ATTORNEYS.

Dec. 19, 1933. I E. J. CROWELLS 1,940,483

SAND DREDGING APPARATUS Filed Dec. 17, 1930 3 Sheets-Sheet 5 NVENTOR 414 4122? J'Crawe'ls A TORNEY Patented Dec. 19,, 1933 I PATEN SAND DREDGING APPARATUS Edward J. Crowells, Detroit, Michg assignor to Edward C. Gritzliaugh Application December'17, 1930 Serial No. 503,049.

10 Claims.

This invention relates to vessels known as sand dredges such as are equipped with pumping apparatus for raising sandand gravel from the water and loading the material in the hold of the vessel.

In the past, it has been the practice to raise sand, gravel, or other desired material, by suction pumping from the bed of a bodyof Water and conveying .this quite fluid material consisting of more water than sand, to the hold of the vessel in the same liquid state in which it is raised up to the vessel, the water constituting. the vehicle by which the solid matter is carried. The great difiiculty in this practice was the hazard of car-' rying the large shifting liquid cargo to port over rough water. Furthermore, the great amount of waste material'carried in such a load in proportion to the percentage of desired and usable material greatly increased the cost of such operations.

Recently, attempts have been made to separate the water from the solid matter desired before loading the material in the hold of the vessel and actually stowing the sand in the hold in a comparatively dry state, while the water used as a carrying vehicle is discharged over the side of the vessel.

This invention relates particularly to an improvement in apparatus for automatically separating the water and sand, or gravel, or dewatering the material dredged and stowing it inthe hold in a comparatively dry state, thereby overcoming the objectionable hazard of transporting a liquid load and obtaining the economies inoperating cost resulting from the ability to handle a load of material, the larger proportion of which is useableand very little waste.

One of the features of this invention is the provision of but one pair of dewatering hoppers located at the stern of the sand dredging vessel and adapted to be used alternately to separate the sand and water, these being the only twodewatering hoppers used. The sand which has been dewatered isthen carriedto the Various parts of the hold to be stowed by a beltconveyor system, novelin design, which insures an even loading. of the material necessaryto maintain an even keel. p

Another feature of, this invention constitutes a novel sand sealer through which the fluid is discharged from the flumes into which it has been pumped into the dewatering hoppers. vA sand sealer is provided at each of the plurality of spoutsthrough whichthe fluid is discharged into the dewatering hoppers and automatically actsto 1 tion.

TOFFICEY f seal any one-of thespouts not-being used in a manner-in which it will not interfere with the operation of: any of the other of the plurality of spouts in the system. J

This'invention contemplates also the use of a combination gravel and sand dredging and screening system utilizing the same suction pump and fiume', and the same hoppers, conveyor and stowing system for both sand dredging and gravel dredging 0perations. Another feature of this invention is the provision of a rock crushing mechanism for convertembodiment.

Various additional features and advantages are specifically mentioned herein-will readily appear.

to one skilled in the art as the description proceeds."

The following description will be more readily understood by referring to t the accompanying drawings, in which view ofthe deck of a sand dredging vessel em- Fig. l is. a fragmentary, diagrammatic plan bodying the improved dewatering and screen selecting sand and gravel apparatus of this inven- Fig. 2 is an enlarged vertical cross-sectional view taken on the line 2-2 of Fig. l, more or less diagrammatic and illustrating the improved apparatus of this invention mounted on the deck of the sand dredging vessel- Fig. 3 isan enlarged vertical diagrammatic side view taken on the line 33 of Fig. 1.'

Fig. 4 is an enlarged detailed view of one of the conveyor belt support rollers taken on' the line 4-4 of Fig.3.

Fig. 5 is an enlarged cross-sectional view of one of the discharge spouts of the fiume and the sand sealer of this Fig. 3.

Fig. 6 is an enlarged cross-secti0nal view of Fig. 7 is an enlarged horizontal sectional view of the spout taken on the line 7-7 of Fig. 5;

invention taken on line 5- -5 of the spout and sand sealer taken on the line 6-6 of Fig.6.

Fig. 8 is an enlarged cross-sectional ,view of the tripper hopper taken on the line 8--8 of Fig. 3,

and V Fig. 9 is an enlarged fragmentary detail plan view of one of the vibrating gravel selecting screens.

Referring now to the drawings in detail, in which like reference characters designate like parts throughout the several views, there is illustrated in Figs. 1, 2 and 3, a sand dredging vessel comprising a hull 11 of standard construction, a suction pipe 12 extending from the hull downwardly into the water which is connected with a centrifugal, or other suitable pump 13, operated by an electric motor 14, or in some other suitable manner. A flume 15 is suitably mounted cross-wise over the top of the deck'of the vessel and is connected with the centrifugal pump 13 to receive material therefrom through a pipe 16. Suitable screening and discharge .spouts 17 are located in the bottom of the flume 15 and are of novel construction producing a sandsealing feature which will be more particularlydescribed hereinafter. These spouts are designed to discharge material into a pair of dewatering hoppers 18, placed side by sidecross-wise of the vessel. Therhoppers 1 8 comprise-essentially two parts, afunnel shapedinterior receiving member 19,.the sides of which are drilled sieve-like to allow water to drain into .a larger funnel shaped exterior flume20 surroundingthe lower part of the hopper.. This fiume is connected at. its lower end in a suitable manner. with discharge or waste outlets22 which emptyover the side of the vessel. A discharge port 23, at the lower end of each hopper, is adapted to be closed by a suitable gatevalve 24, preferably manually operablabut which maybe motor driven if desired. The discharge ports 23, of the dewatering hoppers, are positioned above a pair of reversible conveyor belts -25 of any standard design which are inclined upwardly toward, each other and toward the center of the vessel.

The conveyor belts 25 are adapted to rotate iforwardly in a manner to move the material.

dropped from the dewatering hoppers 18 to a centrally. disposed conveyor belt 26 which .runs lengthwise of the vessel and one end of which is, disposed ,directlygbeneaththe inner. ends. of the conveyor belts ,25. Thejconveyor belt 26 iscarried by a suitable system of rollers to extend from a point slightlyin backof the discharge ports 23 of the hoppers over a roller mounted in a tripper hopper box '28, which is'mountedon wheels and adapted to be rolled over the center of the hatchways, as best shown in Figs. 1 and 3. The belt 26 extends along the deck above the hatchways to the forward end of the'vessel and passes over a suitable pulley or roller at that end which may be driven by an electric motor 30, or in any other suitable manner. The receiving tripperhopper 28 shown in Figs. 3 and 8 is provided with apair of flexible conduits or chutes 31 which extend downwardly. into the hold of the'vessel and are used to distribute and stow the material equally to both sides of the keel of the vessel. The tripper hopper 28'may be mounted upon rails 32 extending longitudinally of, the vessel over the hatchways, if desired, to provide a means of readily moving the tripper hopper from one hatchway onto the next.

In Fig. 8 is illustrated another, feature of this tripper hopper which consists in having the bottom thereof formed in aridge or peak to divide the 'material received from the endless belt 26into.

equalparts, distributed to each side of the hold of the vessel by means of the flexible conduit 31. A suitable gate 2'7 is pivotally hinged or mounted in some other suitable manner at the peak of the hopper as best shown in Fig. 8, for the purpose of directing the flow of material to either one or the other of the conduits 31 when desired to stow the material on one particular side of the hold of the vessel. As shown in Fig. 8 the gate is in an upright position and the material will therefore flow to both of the conduits 31, the gate may be tilted however to either of the positions shown in the dotted lines to close off one of the conduits 31 and cause flow of material to the other. In connection with the belt conveyor system another detailis provided in a roller 33, illustrated in Figs. 3 and 4, positioned slightly above the rails 32 and to the rear thereof, to receive and carry the endless belt 26 when the tripper hopper is moved to a position over one of the hatchways at the forward end of the vessel to prevent injury to the belt in sagging. A pair of side skirt boards 34 are provided to further align the sand or gravel on the endless belt 26 at the start of its movement upwardly toward the tripper hopper. The skirt boards are hinged and rest on the belt 26 to follow it when the hopper 28 is at the forward end of the vessel and the belt lowered over the roller 33.

Referring now to Fig. l of the drawings, it will be noted that the fluine 15 is branched into two sections extending crosswise of the deck of the vesseland so positioned above the de-watering hoppers 18 that each section will be available to dischargesand bearing water intothe de-watering hoppers 18 and when it is desired to stow sand only in the hold of the vessel, both of thesections of the fiuine 15 are utilized. 1

We come now to another feature of this invention, namely, the gravel dredgingand selecting mechanism which is combined to operate with the sand dredging mechanism just described. A gate valve 40 is provided at the fork of the branched flume 15. This valve is used to close off the front section as illustrated in Fig. 1. then secured to the spouts 17 of the rearward section of the fiume after removal of the screens from the spouts so that larger particles of stone and gravel may be dredged. These spouts are positioned to discharge the material dredged, which in this instance, will.constituterelatively coarser particles of stone and'gravel, onto inclined motor driven vibrating screens 42, such as are well known in the art. An electric motor 43 drives the vibrating screens which are usually made up of a pair or more of wire mesh frames decked over each other and vibrated by the rotation of eccentrics to shake the smaller gravel or stones, of a size predetermined by the grade of screen wire used, into the lowerdeck 4 1 of the screen, which will be the smallest sized screen and which acts as a chute from whence the material is discharged into the hopper 18 as best shown in Fig. 3. Downwardly hinged gates 47 are provided in the rear walls of the hoppers 18 which swing inwardly to allow the passage of gravel from the lower deckvibrating screening operations so as to wash the mud and the undesirable accumulation from the gravel being screened. This refuse is discharged,

together with thewater used'as a carrying vehicle for raising the gravel to the fiume, through the discharge and refuse outlet 22 over the side of the vessel. Suitable trap doors 46, are provided in the top of the chutes'41'to provide access for the removal of any obstructions which might tend to block or clog the chutes. which is discharged into the hoppers18 after going through the. screening process will fiow through'th'e discharge ports 23 at the bottom of the hoppers, when thegate valves 24 thereinare opened, and be received by the conveyor belts 25 and carried to the transversely extending center conveyor belt 26 up to the tripper' hopper 28 and thereafter discharged through'the flexible conduit chutes3l into the hold of the vessel in the same manner inwhich' the sand was discharged therein- An additional'feature of the gravel selecting and screeningmechanism just describedis provided in the form of a rock crusher 50, best shown in Fig. 3. This structure comprises any suitable well known type of rock grinding mechanismor converter which may be operated by an electric motor if desired, or in any other suitable manner.

The oversize gravel or stone whichwill not pass. through the inclined vibrating screens 42 remains on the'top deckof the screening and will flow and be shaken to the lower end, thereof and engage a partition board 49 extending across the top deck of the screening as shown in Fig. 9. This oversized material is directed by the board 49 into a chute 51 which conveys this gravel and stone to the rock crusher whereit is ground up and reduced in size. An endless elevator belt 52suitably mounted on a series of gears'or pulleys and driven by the motorwhich operates .the rock crusher is provided with a plurality of buckets or carriers 53 for raising the crushed rock after. it has been reduced in size by the rock crusher and dumping or delivering this material into a chute .54 which'returns it to the motor'driven vibrating screens to pass through the screening and selecting process again. By this method, the larger stone and gravel is converted into useable size rather than discharged through the waste chute 22. i

A novel feature of this invention is the provision of what is termeda sand sealer in place of the common type of discharge spout which has peculiar advantages and novelties which are ,found to be very advantageousin the art. This sand sealer is best illustrated in Figs. 5, 6, and 7,

andconsists in having the spout 17 formed into 3 a. bell shaped housing, wider, at the bottom than n at thetop portion. g

A screening box 57 is secured to the bottom of the fiume 15in a suitable manner and a screen 58 is mounted at the upper part of the screen.

box 57 for screening out the larger parts of gravel when sandis being dredged.

The bell shaped spout is suitably secured to the bottom of the screen box 57 and communicates therewith through a comparatively restrict- -i opening56 at the upper portion thereof. A relatively larger. discharge opening 55 is formed at the lower end of the spout, and the bottom of the 'bell shaped spout is flanged inwardly at 54 to assist in trapping. sand particles suspended in the infiowingwat'er received from the flume. It will be noted that the bell shapedspout is peculiarly formed having its sides converging inwardlyf at the upper portion thereof. This is for the purpose of trapping sand as, will more fully be described hereinafter. f r I A shutoiT gate-valve 60 is pivotally mounted at the back of the spout atv 61 and has aforwardly The gravel .Upon filling of the be discharged In the use of a common straight walled or funnel. shaped spout the closing of the gate-valve results eddying, boiling and tur-,

in a very undesirable one of the spouts 17 to the material is being bulent bounding of the liquid material as it rushes over the unused'spoiitwith and shaking of the fiume causing undue Wear of the flumeand associated screens,spouts and shutofigates. Furthermore, the rebounding action of the material as it reachesthe' closed spout, results in blocking of the chute preventing flow of material to thespouts disposed farther down the. flume; In cases where an open top fiume is used vit results in loss of material over the sides of the a resultant vibration fiume. Upon closing of the gate valve 60 the.

peculiarly designed bell shaped. spout of this in-.

vention will quickly become filled with sand. The restricted opening 56 traps the solid particles of sand which settle and accumulate at the bottom of the closed spout and the water willswirl out and on down the n me while'the sand remains.

'I his action of trapping the sand will begreatly aided by the flange 54, the edges of which engage particles of sand in the inrushing water andjretain them. The path of inflow; the bell shaped housing. will be downwardly in the center of the spout as directed by there stricted upper inlet opening 56 the inrushing center stream of sand bearing water. This action results in the particles of sand being baffied byv the clined sides being forced out along this n and thence up-f wardly,.after striking the gate 60, alongthein-A path by I converging sides of the of the water in.

spout and remaining therein as the water passesout and on down the fiume. spout 17 is filled the screen box 57 will be filled in a like manner, and as the sand packs under the screen 58 that particular. discharge spout.17 will be closed oiT from the rest of the system to prevent the undesirableeddying and bounding of the 17. A trap door 65 is provided flume above each of thesand in the top of the sealing spouts 1'7 .When the bell water and material rushing bythe closed spout to provide readyaccess for repairs or removal of, 5

any obstructions.

- In operating the dewatering and dredging apparatus, hereinabove described, .it will be found preferable to close one of the hoppers by shutting Y the gate-valve 24 at the bottom thereof and allowing the hopper to become 60 of the spouts 17 may then be closed over the particular dewatering hopper which has been so filled with the material dredged and pumped up to the flume, The gates filled and the other dewatering hopper filled in asimilar manner. While the second hopper is being filled, the water will drain through the sievelikereceiving funnel 19, separate'from the sand, and'escape through the waste spouts 22 ove the side of the vessel.

24 of the first filled is now. dewatered, may beopened and the convveyor belt system started into. operation to convey second hopper. or nearing the completion of said filling, the gate or valve hopper, in which thesand the comparatively dry sand to the transversely extending conveyor belt 26, from whence it will through the .tripper hopper 28 4. eguallyto both sides of the hold through the flex} ible conduits 31 as hereinbefore described. As the second hopper becomes filled and the first one emptied, this procedure may be reversed, that is,

' 5 the first one closed to be refilled as the degravel entering the hoppers 18 by means of the chutes l, through the gates 47 and the vehicular waterand undersized refuse material is being discharged through the waste outlet 22 over the side of the vessel; The oversized gravel flows through the chutes 51 to the rock crusher or converter 50 and is returned in a reduced state to the screenas hereinbeforedescribed by means of the endless elevator or conveyor 52. It will be noted that-the pair of crosswise extending conveyor belts 25 below the'hoppers are reversible and may be reversed when it is desired to discharge mate rialdirectly into the hold immediately below the hoppers.

The invention herein disclosed provides a combination sand and gravel dredging and screenin'g system wherein the sand is dewatered and delivered to thehold of the vessel in a com paratively dry state being washed, screened and removed from the vehicular dredging water be-' fore delivery to the hold of the vessel. The improved apparatus of this invention is simple, in form and efficient and economical in operation having but two hoppers which are 10 cated near'the stern of the vessel whichdewater all of the sand which is stowedin the hold and an automatic conveyor belt system for stowing the material in the hold whereby the largest amount of the water raised by the dredge pump is removed from the sand before it is stowed in thhold, resulting in nearly an entirely useable cargo, overcoming all of the difficulties which existed in transporting a liquid load. 'Ifhe use of but one pair of hop'pers positioned near the stern'of thevessel assures a I of 'deck room. The combined gravel-selecting mechanism utilizing the same flumes, the same matic stowing apparatus results in many economies and enlarges greatly the utility oi a single dredging vessel; The novel sand sealing device The'scope ofthepre'sent 'inventiorris set forth in the' append'e d claims. z a q .r 1. Inf a vessel for; dredging andiranspo'rting material such as sand'and" gravelfimean's to maximum amount hoppers and the same conveyor belt and autoshaking of the that the above described grains pumpthe material on board-the vessel, a pair oi'rlum'es extending crosswise of the 'vessel to receive theimaterial, a pair of dewatering hoppers disposed below fiumes positioned on the deck s crosswise of the vessel, means to allow flow of material from the flumes alternately to each of said hoppers, a valve gate at the bottom of each of said hoppers to alternately empty the dewatered'material from the hoppers and a belt conveyor system" adapted to distribute the material evenly to all partsfof the,hold..

tudinally of the deck of said vessel over the 1 0 hatohways tofacilitate the positioning of the tripper box over each of the hatchways successively todistribute the material evenly to both sides of the keel of the vessel. r

3. In dredging apparatus having a pump to raise sand bearingwater'to a flume from whence it is discharged into dewatering hoppers, a

screened discharge spoutdisposed in said flume adapted to discharge the dredged materialinto the dewatering hoppers comprisinga screen box,

a bell shaped outlet disposed below said box, a

gate pivotally mounted at the bottom thereof adapted toclose said outlet, the walls of said outlet converging inwardly at the upper end to provide a restricted opening therein to form said trap whereby sand particles ,will rapidly be separated from the vehicular water and fill the entire discharge spout with sand.

4. In sand dredging apparatus meansto pump vehicular water bearing particles of sand suspended therein on board a vessel, flumes to receive said material, dewatering hoppers located below said flumes adapted to receive material therefrom, screened discharge spouts in said flumes to discharge the material therefrom into ,said hoppers comprising outlets having a closure therein and restricted at the upper end. and flared outwardly at the lower end thereof where? by sand will rapidly be separated from the ve-' hicular water and fill the housing when the outlet is closed.

5. In dredging apparatus provided with a flume and a hopper toreceivedredged material there.- from, a discharge spout comprising a screened box, an outlet formed below said box having a restricted opening at the upperend thereof and a gate valve closure at the lower end of said outlet.

6. In dredging apparatus" provided with'a'fiume a and hopper to receive dredged, material therefrom, a discharge spout comprising a screened box, a

bellj shaped outlet formed below said'box hav-, ing the walls thereof converged inwardly toward, the upper endof said outlet and a gate valve closure at the lower end of said outlet.

7. In dredging apparatus provided with a fiume and hopper to receive dredged material there- 7 from, a discharge spout comprising a bell shaped outlet converging inwardly at the upper portions.

thereof, an inwardly extending peripheral flange,

formed at the lower "portion of said outlet, and also gate valve closure at the lower end of said outlet.

8. In a vessel for dredging and transporting material, such as sand and gravel, means to pump the material on board the vessel, a fiume disposed V crosswise of the vessel to receive the material, dewatering hoppers disposed below the flume and positioned on the deck crosswise of the vessel, means to allow flow of material from the flume to the hoppers, valves to allow flow of material from said hoppers after the material has been dewatered and a system of belt conveyors to re-. ceive the material from the hoppers and distribute it evenly to the various parts of the hold of the vessel.

9. In a vessel for dredging and transporting material, such as sand and gravel, means to pump 1 the material on board the vessel, a 'flume disposed crosswise of the vessel to receive the material, dewatering hoppers disposed below the fiume and positioned on the deck crosswise of the vessel, means to allow flow of material from the flume to the hoppers, means to allow the solid material to flow from the hoppers after the material has been dewatered, a pair of belt conveyors under each hopper adaptedto convey the material received therefrom to the center of the vessel, and a second belt conveyor extending the first mentionedconveyors-to distribute it evenly to all parts of the hold.

10. In a vessel for dredging'and transporting material, such as sand and gravel, means to pump the material on board the vessel, fiumes disposed crosswise of the vessel to receive the material, dewatering hoppers disposed below the flumes and positioned on thedeck crosswise of the vessel, means to allow flow of material from the flumes to the hoppers, means to allow the dewatered material to flow from the hopperswhen the water has been separated from the solid matter, belt conveyors to receive the material from the hoppers, a plurality of hatchways in the deck of said vessel and a tripper box associated with said conveyor system and adapted to be positioned alternately over each of said hatchways to divide the

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