US1759490A

US1759490A - Hydraulic dredging system

Info

Publication number: US1759490A
Application number: US81649A
Authority: US
Inventors: Neveling Aloys
Original assignee: Individual
Current assignee: Individual
Priority date: 1926-01-16
Filing date: 1926-01-16
Publication date: 1930-05-20
Anticipated expiration: 1947-05-20

Description

May 20, 1930. Aj NEVELING HYDRAULIC DREDGING SYSTEM 2 faz/n May 270, 1930. A. NEVELING HYDRAULIC DREDGING SYSTEM Filed Jan. l5

1926 4 Sheets-Sheet May 2o, 1930.y

A. NEVELING HYDRAULIC DREDGING SYSTEM Filed Jan. '16 1926 4 Sheets-Shet juz/mo? @m/M@ @wf/MM@ May 20, 1930. A. NEVELING HYDRAULIC DREDGING SYSTEM Filed Jan. 16 1926 4 Sheets-Sheet 4 Patented May 20, 1930 UNITED STATES ALOYS NEVELING, OF CHICAGO, ILLINOIS HYDRAULIC DREDGING SYSTEM Application filed January 16, 1926. Serial No. 81,649.

My invention relates generally to hydraulic dredging system and the method of operating the same to separate the soil, sand, gravel, or other solid material from the bed of the river, lake, or other source, dilute it with water, and transport the same rto a distant desired point. My invention has, more particularly, to do with such a system comprising a cutter adapted to separate such lo solid material from its'source and deliver it to the inlet of a suction pipe; a pump connected to and for producing a suction in said suction pipe; and a discharge pipe for connecting the discharge side of the pump to a distant point for final disposition of the dredged matter; and wherein a compensating means is employed at the inlet to the suction pipe for aiding and compensating the suction in the suction pipe produced by said pump to increase the effective entrance head to insure a greater and more uniform mixture volume flow into the suction pipe and through the same to the pump under all operating conditions, without varying the suction effect of said pump.

Herctofore, in the operation of hydraulic dredging systems of the general class referred to, it is found that a comparatively high vacuum must be produced and maintained by the pump in the suction pipe adjacent to and near said pump in order to produce a sufliciently high vacuum at the inlet to the suction pipe to produce a sufficiently high entrance head pressure at that point to Cause the material segregated by the cutter to be properly mixed and to enter and pass through the suction pipe in the proper mixed proportions. This condition may exist, as explained, because in the use of such apparatus, the inlet end of the suction pipe, in opcrative position, is located at a lower level than the pump and, in most cases, the suction pipe yis of considerable length in order to bring the cutter' into contact with the material to be dredged; and because, under these conditions, although the pump produces a desired suction condition and head in the suction pipe at or near said pump, the degree ofy said vacuum and head is gradually reduced, due te the friction of the pipe other obvious elements, so that, at the en d of the suction pipe opposite the pump, the vacuum and head is very low. With this condition existing, it becomes necessary in certain instances, and when working upon. heavier solids, and solids which may tend to clog, to operate the pump so as to produce a very high vacuum condition or head in the suction pipe at or near the pump in order to proportionately produce a higher and ,eifec- S0 tive vacuum or entrance-head at the inlet end of the suction pipe to cause such certain heavier or clogging solids to enter and rise in said pipe toward said pump.

When the degree of vacuum in the suction pipe is increased as stated, the velocity of the Water in the suction pipe is increased, and as this high velocity water enters the high vacuum section of the suction pipe, there is a tendency for the air in the water, and the component parts thereof, to rapidly expand. This results immediately in a reduction of the vacuum in that section of the pipe with a resultant tendency to restore the water to its original condition. This action results in what is known to those skilled in the art as the water hammer. The reaction, in such a case, is so great that the pressure applied to the suction pipe wall is sufficiently great, in most instances, to burst the pipe, resulting 8O in the obvious destructive effects.

One of the objects of my invention is to produce a condition wherein the dredged solids may be delivered, admixed and passed through the. suction pipe in suspension in the high velocity water without creating such a vacuum condition in the suction pipe as would tend to cause water-hammer.

Another object of my invention is to provide for the formation of the desired mixture and uniform delivery of the dredged material by increasing the entrance head of the suction pipe to any desired degree without increasing the suction effect of the pump.

A further object is to effect a uniform iiow of the mixture through the suction pipe regardless of the character of the material dredged by insuring a sufciently high suction at the inlet to the pipe and by' increasing velocity at that point with aconipa ,1;a-v loa tively low suction to cause the material cut to readily pass into the inner portion of the 1 e. p Itill another object of my invention is to prevent clogging of the inlet end of the suction pipe.

Other and further objects and advantages will become apparent and will be referred to as this description progresses.

In carrying out my invention, I may mount my dredging apparatus upon a suitable barge or other support in dredging position. In dredging, the cutter is lowered to the bank, bed, or other source of Athe ina'- terial to be dredged. The cutter is then caused to operate in such a manner as to 'separate the material from its source and deliver it toward the inlet end of a suction pipe. The other end of the suction pipe is connected to a suction producing means so that there is a partial Vacuum created in the suction pipe Vwith a resultant entrance head tending to suck the segregated material delivered by the cutter toward the inlet end of the pipe thereinto in a well recognized manner. The segregated material delivered into the inlet end of the suction pipe .is mixed with, and carried along in suspension with, water Which also enters the inlet end and the mixture is delivered thence to the pump and is discharged by the pump into a discharge pipe to a desired distant point. In carrying out my method I particularly provide for the operation of the suction pump to produce only such a vacuum in the suction pipe adjacent thereto as would not tend to cause a Water-haminer, While at the same time providing a suiificiently high suction at the inlet to the suction pipe to eifect a uniform vdelivery of mixture into the suction pipe inlet and its passage therethrough to the pump. I accomplish this by increasing the entrance head at the inlet end of the suction pipe. I increase t-lie entrance head by superimposiiig an additional suction at the inlet to the suction pipe, whereby an additional effective head is added to the entrance head produced by the main suction pump. In order to produce a uniform mixture and iii-flow at the entrance to the suction pipe under all operating conditions without increasing the suction to an undesired and water-hammer point, I vary the degree of the suction superimposed at theinlet without varying the suction of the main suction producing means, thus varying according to the conditions of use, the superimposed and total effective entrance head. Thus also, in eiiect, an increased velocity zone is created at the inlet to the suction pipe with the use of only a comparatively low suction whereby the tendency to clog is eliminated and the cut material will readily pass into the suction pipe. Furthermore, I render the additional suction effective in such a way as to not only increase the entrance head pressure but to also assist the suction pump in drawing the already admitted mixture through the suction pipe by imposing an additional positive pressure on such mixtuie, thus, in effect, also increasing the head inthe pipe. One form of apparatus which I may employ in carrying out my invention is shown in the drawings wherein,-

Fig. 1 is a side elevation of a dredging vessel or barge equipped with dredging apparatus in accordance with my invention.

Fig. 2 is an enlarged vertical section of the inlet end of the suction pipe, showing the cutter in elevation and in substantially voperating position for dredging.

Fig. 3 is a. partial side elevation of the inlet i end of the suction pipe and structure shown in Fig. 2, the cutter being removed.

Fig. i is a top plan view of the structure of Fig. 3.

Fig. 5 is a section taken on line 5 5 of Fig. 3, that is, a horizontal section through the inlet nozzle of the suction pipe.

G is a front elevation of the structure fof Fig. 3.

Fig. 7 is a section-taken through the inletV end of the suction pipe substantially on linc 7-7 of Fig. 5.

Fig. 8 is an enlarged detail section taken on line 8 8 of Fig. 7, showing the construction of the liet .nozizles in the inlet end of the suction pipe,rit being understood that the jet nozzles of the other figures are of similar construction but shown without minute detail to avoid confusion which might otherwise result.

Referring particularly to the drawings, Figure 1, the numeral 1, designates a dredging vessel having mounted thereon an engine 2, which may be of anydesired type adapted to drive the centrifugal pump 3. A discharge pipe i of the desired length is connected to the discharge side of the pump 3, and to the suction side of the pump there is connected a suction pipe 5. Mounted at one end of the dredge 1 is the cutter (i, this cutter being fixed to a drive shaft 7 adapted to be rotated through the gear and pinion construction 8 and 8a by any desired means (not shown). The cutter 6 is arranged and supported for movement toward and from its operative position-with the free or inlet end of the suction pipe 5 by the boom 9 and the associated block 10, pulley 11, liiie 12 and winding drum 13, it being understood that as the drum 13 is movedV to Wind or unwind the line 12, the cutter 6 and free or inlet end of the suction pipe 5 are raised or lowered, respectively. The pulley 11 may be attached to the cutter structure in any suitable manner.

The suction pipe 5 is of such length that it extends to, and internally of, the cutter 6. This pipe may be jointed at or near the point l-SO lthe beams 16 and 16a.

tween two parallel beams 16 and 16a which may be held together rigidly in parallel formation by any desired means in addition to that to be hereafter described. These beams 16 and 161 are pivotally connected to the dredge y1 as at the point 14 in any desired manner to permit their joint upward or downward movement. The section 15 of the suction pipe which passes between these beams is supported thereby as at 14 (Fig. 1) and by the bracket 17 which is preferably carried integrally with and by the inlet nozzle 18 of such pipe 8 and attached by the bolts 19 to the beams. The inlet nozzle 18 of the suction pipe is joined to the section 15 as at 15a in an obvious manner. Other and any desired number of brackets of any suitable construction may be used to further support and connect the suction pipe section 15 to the beams, dependent upon the length of such section. The cutter shaft 7 is also rotatively supported by this structure by bearing brackets 20 (Fig. y1) disposed throughout the length of such shaft (except at its lower end), these brackets being rigidly carried by The lower or cutter end of this cutter shaft 7 passes through, and is journaled in, a bearing 21, preferably, formed integral with the bracket member 17, although it is obvious that it may be detachably secured thereto by bolts or screws or the like.

lThe suction pipe inlet nozzle is of flared construction in order to best receive the material projected toward it by the cutter 6 and to insure a full section flow of the dredged mixture into the suction pipe in accordance with established principles of construction obvious to those skilled in the art. This inlet nozzle 18 may be formed as a part of and integral with the bracket member' 17 and the bearing member 21 as shown (Figs. 2, 3, 4, and 6) or may be a separate detachable part secured to said parts for movement therewith. From the foregoing it is obvious that the unit, comprising the section 15 of the suction pipe with its nozzle 18,

beams

16 and 16, and the rotary cutter shaft 7 with its cutter 6, is moved as a whole upward or downward by movement of the drum 18 as hereinbefore explained.

In order to superimpose an additional entrance head or to increase the entrance head at the inlet 18a of the suction pipe inlet nozzle 18, I employ a water jet arrangement adapted to create a vacuum or .suction of any desired degree directly at that point, this, as hereinbefore explained, being in addition to the suction of the suction producing pump 3. To accomplish this I may enlarge the cross-section of the flared rim portion of the inlet nozzle 18 andy provide thereinthroughout its circumference an annular chamber 22 which is in' direct communication with a water pump 24 through a water line v25, and also in direct communication with the interior of the inlet nozzle 18 at its inlet 18a through an annular series of uniformly distributed jet passages or Ynozzles 23. These jet nozzles are arranged and directed inwardly from the chamber 22 along converging lines so as to direct uniformly distributed jets of water under a variable pressure to a common point in the center of the inlet portion of the nozzle 18 as at A in Figures 2' and 5. The jet passages 23 are arranged sufficiently close together to form in the inlet, in

effect, a cone-shaped sheet of water converging and passing on into and through the inlet nozzle 18 in stream formation and under any desired pressure (dependent upon the water pump 24) at all stages. This action is such, and the pressure under which the water is forced through the jet nozzles is such, and the water maybe traveling at such a velocity that, by the displacement action which takes place, a variable suction, in addition to that produced by the pump 3, is produced in the entrance 18@L to the inlet nozzle 18 in accordance with principles commonly known and well understood generally. It is also seen that this water jet arrangement sets up an increased velocity zone or condition at the inlet 18a by, in effect, restricting the inlet to variable extents dependent uponv the pressure under which the water issues from the jet nozzles 28, the yincreased velocity at the point stated being produced with a comparatively low suction throughout the suction pipe.

The pump 24 may be driven in any suitable manner as by the motor or engine 26 through shaft 26a. The water line 25 may be of such material and so mounted as to be carried along withthe cutter and suction pipe unit when the same is moved up or down (Figs. 1, 3 and 4). This water pipeI is connected to the nozzle 18 so as to be in communication with the chamber 22 as at 25a (Fig. 7). The pump 24 may be of such construction that it will draw the water from the source (which may be the body of water which supports the dredge 1) and discharge the same through the pipe 25 to the chamber 22 at any desired velocity and under any desired pressure to suit the particular operating needs as determined by thecharacter of the solids worked upon and the pressure condition or entrance head set up or established by the centrifugal pump 3.

In order to provide vfor the projection of the water jets into the inner portion of the inlet nozzle 18 in the most advantageous 'Lf-arm, I may thread the jet' passages 23'inter.-

nally as at 23 for the reception of an apertured bushing 27 having the aperture 27' therein. The passage 23 is threaded throughout its length to permit adjustment of the bushing to any desired position therein relative to the outlet to vary the flaring or spread- Ying effect of the jet of water which issues from the aperture 27a to insure the proper displacement effect on the interior of the inlet nozzle 18. This adjustment may be used jointly with the variation in pressure of the water to vary the effect just stated. Still further bushings having different size apertures may be substituted for the bushinor 27 to accomplish further adjustment under varying operating conditions lto accomplish the foregoing desired suction or booster effect.

From the foregoing it isrobvious that a suction, in addition to the suction of the pump 3, is imposed and renderedv effective at the inlet 18, whereby the effective entrance head is increased and the results hereinbefore set forth obtained. This added entrance head may be increased or diminished and, consequently, the total entrance head may be increased or diminished by increasing or diminishing the pressure under which the water is forced through the jet nozzles 23, by t adjusting the bushing 27 relative to the outlet from nozzle 23, or by varying the sizeof the aperture 27a, all of these factors being adjustable collectively or individually to accomplish the result stated.

Y In the operation of this structure the pump 3is operated together with the pump 24 to suck the mixture of Water and solids into and through the suction pipe 5, the pump 3 discharging the same through the discharge pipe 4. The et arrangement is variableto maintain the desired entrance head at the 1nlet 18a. The Water issuing through the nozzles 23, that is, the jet arrangement, in addiworked. In other words, the pressure of the jets upon the already admitted mixture is, in effect, a pressure imposed in addition 'to the normal atmospheric pressure acting on the mixture due to the production of a partial vacuum in the suction pipe 5. In practice it has also been further demonstrated that the water discharged through the nozzles 23 serves to lubricate the entrance to the inlet portion of the suction pi e. This fact together with the suction an impelling actions of the water passing through the nozzles positively insures that clogging and water-hammer conditions will not exist at the inlet to the suction pipe. The suction-impelling-lubricating'action of the water jets also (as demonstrated in practice) positively breaks the material Vbeing' worked, at the Sametime,

eliminating the necessity of operating the main suction pump, such as the pump 3, t0 produce an excessively 'high vacuum condition in the suction pipe adjacent thereto in order .to produce the required entrance head when workin g on heavier solids or solids that tend to clog, thereby, in turn, eliminating all danger of the so-called water-hammer condition and its corresponding destruction.

I claim:

In a hydraulic dredge, a suction pipe, a pump for producing a suction and a predetermined entrance head in said pipe, and means for boosting said entrance head independently of said pump, said means comprising an annular chamber disposed in the inlet portion of said pipe and in communication with the interior inlet portion thereof at the point where the dredged material enters, through a plurality of annularly disposed and inwardly directed passages, apertured bushings adj ustably carried in said passages, a waterforce pump connected to said annular chamber for forcing water under pressure to said annular chamber and through said apertured bushings, said bushings being adjustable relative to the outlet of said passages to determine the character of the jets a passing therethrough and vary the entrance l my name.

ALOYS 'NEVELINGL