US2784674A - Air separator and equalizer for dredges, including pump primer - Google Patents

Description

March 12, 1957 Filed May 13. 1955 R. CARVER ET A AIR SEPARATOR AND EQUALIZ L ER FOR DREDGES, INCLUDING PUMP PRIMER 2 Shedtm-Shpot I Royall 5. Carver Leroy A Carver INVENTORS R. 's: CARVER ET AL 2,784,674 AIR-SEPARATOR-AND EQUALIZER FOR DREDGES. mcwnmc; PUMP PRIMER March 12, 1957 Filed May is. 1953 2 "Shoots-Sheet 2 Royall .S. Carver Leroy A. Carver 'INVENTORS United States Patent 0 AIR SEPARATOR AND EQUALIZER FOR DREDGES, INCLUDING PUMP PRIMER Royall S. Carver and Leroy A. Carver, Washington, N. (1.

Application May 13, 1953, Serial No. 354,688

7 Claims. (Cl. 103-113) This invention relates in general to improvements in dredging equiment, and more specifically to an air separator and equalizer for dredges including a dredge pump primer.

Dredges engaged in dredging operations in streams and rivers and the like have repeated shut-dowu periods due to the development of air locks in their centrifugal pumps. The air locks are due to the presence of air and gases of various types in the sand and muck which form the bottoms of the bodies of water being dredged. These air and gases mixed with the water and solids are drawn into the centrifugal pumps of the dredges with the result that the air remains in the centrifugal pump and causes the pump to be air bound. Not only does the presence of air within a centrifugal pump eventall'y cause the pump to be air bound, but the existence of any air cuts down the efficiency of the centrifugal pump.

It is therefore the primary object of this invention to provide an air separator unit adapted to be connected in the suction line of a dredge intermediate the suction head and the centrifugal pump thereof for removing substantially all air and gases from the dredged materials prior to their passage into the pump so as to elimimate the possibility of the pump being air bound.

Another object of this invention is to provide an improved air separator for hydraulic dredges, said air separator including an elongated chamber for receiving all dredged materials passing into the centrifugal pump of the dredge, said chamber being provided with a least one air space in the upper portion thereof for receiving air from the dredged materials, the air separator including air evacuation means connected to the air space for withdrawing air under vacuum from the same.

Another object of this invention is to provide an improved air separator and equalizer for dredges which is of a relatively simple construction and which is rela' tively compact so as to be adapted for mounting in both new and existing dredges.

A further object of this invention is to provide an equalizer for hydraulic dredges, said equalizer being in the form of an enlarged chamber disposed between the suction head and centrifugal pump of the dredge, the chamber being adapted to retain a quantity of water and dredged material so that the load imposed upon the centrifugal pump will remain substantially constant. regardless of fluctuations of the amount of solid dredged material being drawn into the suction head;

A still further object of this invention is to provide an improved air separator and equalizer for dredges which is intended to remove air from dredged materials through the use of a suction pump, the dredge being so arranged whereby the suction pump may be utilized to draw air out of the suction lines and pump of the dredge and water into the same so as to permit ease of priming of the pump.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereice 2 inafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a diagrammatic View of a hydraulic dredge pumping system and shows the air separator and equalizer which is the subject of this invention mounted therein;

Figure 2 is an enlarged front elevational. view of the air separator and equalizer and shows the general arrangement of the same, portions of the air separator and equalizer being broken away and shown in section in order to clearly illustrate the construction of various parts thereof;

Figure 3 is a side elevational View of the air separator and equalizer of Figure 2, parts of the air separator and equalizer being broken away and shown in section;

Figure 4 is an enlarged fragmentary elevational view showing the relationship of the float control valve and its associated float, the intermediate portion of the fioat being omitted and the valve being broken away and shown in section in order to illustrate the operating parts thereof; and

Figure 5 is an enlarged fragmentary sectional View taken substantially upon the plane indicated by the section line 55 of Figure 2 and shows the manner in which the float is guidingly mounted within an associated tank to guide the vertical movement of the same.

Referring now' to the drawings in detail, it will be seen that there is illustrated in Figures 2 through 5, inclusive, the air separator and equalizer which is the subject of this invention, the air separator and equalizer being referred to in general by the reference numeral lit. The air separator and equalizer it includes an elongated chamber which is referred to in general by the reference numeral 12.

The chamber 12 includes a semi-circular cross-sectional bottom portion 14 which terminates at its forward end in a pipe section 16 which is provided at its forward end with a connecting flange 19. The rear of the bottom portion 14 terminates in a rearwardly extending pipe section 20 which is provided at its rear with with a connecting flange 22.

The chamber 12 also includes a pair of upwardly diverging side walls 24 and 26 whose upper edge is of a saw-tooth configuration. The chamber 12 is completed by a front end wall 28', a rear end wall 3t) and a top wall 32, the top wall 32 being provided with a vertical intermediate portion 34.

Due to the saw-tooth configuration of the upper portions of the side walls 2'4 and 26 and the configuration of the top wall 32, the chamber 12 is provided with a pair of air spaces 36 and 38, the air space 36 being disposed forwardly of the air space 38. It will be understood that dredged materials are to enter the chamber 12 through the pipe section 16 and that air and gases contained therein will have a tendency to move up into the air spaces 36 and 38 to permit separation thereof from the solid and liquid dredged materials.

Secured to the forward portion of the top wall 32 and communicating with the air space 36 is an enlarged vertically extending pipe section 4%. The pipe section 49 is disposed adjacent an enlarged tank which is referred to in general by the reference numeral 42 and is connected thereto by vertically spaced piping 44, the piping 44 being provided with suitable connections 46 to permit the pipe 44) to be disconnected from the tank 52.7 The tank 42 is suitably supported by standards 48 so that the bottom wall 50 thereof is substantailly level with the top of the air space 36.

The tank 42, in addition to the bottom wall 50, includes a cylindrical body portion 5'2 and a removable top wall 54. Mounted within the tank 42 is an elongated float 56. The float 56 is in the form of a hollow container and has depending guide members 58 secured to the lower end thereof. Vertical movement of the float 56 is guided by the guide members 58 being disposed within fixed guide elements 64 carried by the lower portion of the tank 42. The guide members 58 have their lower ends normally in engagement with the bottom of the tank 42 to properly position the float 56.

Passing through the top wall 54 of the tank 42 in sealed relation therewith is an outlet pipe 62. The outlet pipe 62 has secured to the lower end thereof a valve 64 which may be in the form of a generally conventional globe valve. The globe valve 64 is modified to the extent that its stem 66 has the threads removed therefrom so that the valve 64 may be controlled by moving the stem 66 in and out of the valve body. The lower end of the stem 66 is connected to the top of the float 56 by a collar 68 so that the valve 64 will be controlled by vertical movement of the float 56. The valve 64 is also provided with an inlet 70 which communicates with the interior of the upper portion of the tank 52.

Disposed adjacent the chamber 12 is a tank which is referred to in general by the reference numeral 72. The tank 72 is provided at its lower ends with suitable supporting legs 7 and has passing through a top wall thereof a pipe 76. The pipe 76 depends a substantial distance witl in the interior of the tank 72 and has its opposite end connected to the pipe 62 by a pipe 78.

Also connected to the top wall of the tank 72 is a vacuum line 79 which has mounted therein a suitable vacuum gauge 80.

Referring now to Figure l in. particular, it will be seen that there is illustrated the dredging equipment of a conventional hydraulic dredge. The dredging equipment of a conventional hydraulic dredge includes a centrifugal pump 82 which has connected to its intake a suction line 84 which terminates at its forward end in an intake or a suction head 86. The centrifugal pump 82 also has connected to its outlet, outlet piping 88 so that the materials drawn in through the suction head 86 may be distributed at the desired location.

It will be noted that mounted in the suction line 84 is the air separator and equalizer 10. It will also be noted that the dredging equipment includes a vacuum pump 90 which is connected to the vacuum line 79 and is intended to draw air from the air separator and equalizer i The vacuum produced on the vacuum line 79 is controlled by a suitable valve 92.

Referring now to Figures 2 and 3 in particular, it will be seen that when dredged materials are drawn into the chamber 12 through the use of the centrifugal pump 52, air and gases carried by dredged materials will escape upwardly into the air space 36. The air and gases passing into the air space 36 will then pass into the tank 42 through the pipe 40. In order that air and gases trapped in the air space 38 may also pass into the tank 42, there is provided a pipe 94 which connects the air space 38 with the interior of the tank 42. It is pointed out at this time that the number of air spaces in addition to the air space 36 may vary depending upon the size of the dredge equipment. However, it will be understood that each additional air space 38 will be provided with a pipe, such as the pipe 94, connecting it to the tank 42.

Inasmuch as the tank 42 is connected to the vacuum pump 9% through the various piping and the tank 72, it will be understood that there will be water within the major portion of the tank 4-2, the height of the water in the tank 42 being directly dependent upon the differential in vacuum between the suction line 84 and the vacuum line 79. When the water level in the tank 42 is normal, the float 56 will remain at its lowermost position and the valve 64 will be open. Thus, air passing into the tank 42 and moving into the upper portion thereof will be drawn off into the tank 72 and thence, through the vacuum line 79, into the suction pump 90. Any water and sand which is drawn into the tank 42 through the pipes and 94 which will increase the level of the water in the tank 42 will be passed back into the chamber 12 through a sand return line 96 which extends from the bottom of the tank 42 to the bottom portion 74 of the chamber 12.

It will be understood that a slight amount of water will be drawn into the tank 72. The purpose of the tank 72 is to remove all water which may pass into the vacuum line 79. in order that the tank 72 may be periodically drained, the same is provided with a suitable drain 98.

In the event that the suction in the vacuum line 79 should increase over that in the suction line 84 to the extent that the water level in the tank 42 raises to the point where Water would enter into the valve 64, the float 56 will move upwardly, due to its increased buoyancy with the resultant closing of the valve 64. In this manner, the entrance of Water directly into the pipe 62 is automatically prevented.

From the foregoing, it will be seen that there has been illustrated and described a suitable air separation system which will remove air and gases from dredged materials passing into the suction head 86 of hte dredge equipment. The removal of the air and gases from the dredged material prior to their entrance into the centrifugal pump 82 will prevent the centrifugal pump 82 from being air bound and therefore necessitating the shutting down of dredging operations until such time as the air may be bled therefrom and the pump reprimed.

In a normal dredging operation, especially when dredging a sandy bottom, the relationship of the solids to the liquids varies with occasionally substantially pure solids being drawn into the suction head 86. This condition normally places an undue burden on the centrifugal pump 82 which is not intended to accommodate over a certain percentage of solids. This is hard on a centrifugal pump, such as the centrifugal pump 32, and causes undue wear on the pump as well as the possibility of damaging of drive machinery thereof. Inasmuch as the air separator and equalizer 10 includes the enlarged chamber 12 which is provided with a reserve supply of water, including the water in the tank 42, it will be seen that should at any time there be an increased percentage of the solids of the dredged material upon the entrance of such dredged materials into the chamber 12, the additional water will mix with the dredged materials so as to equalize the load on the centrifugal pump 82.

Inasmuch as numerous types of solids and other material will pass into the chamber 12, in order that the chamber 12 may be periodically cleaned, the rear wall 30 thereof is provided with a suitable hand hole which is closed by a hand hole cover plate 106. The hand hole cover plate 100 is removable, and facilitates the entrance of cleaning devices into the chamber 12.

When a dredging operation is to be started, it is necessary to first prime the centrifugal pump 82. This re quires that water be drawn into the suction line 84 and that all air be removed from both the suction line 84 and the centrifugal pump 82. For this purpose, there is normally provided a small suction pump which is used to evacuate the air from the suction line 84 and 82.

In order to eliminate the small suction pump mentioned above, the tank 42 has connected thereto above the normal level of water therein a suction line 102 which is controlled by a valve 104. The suction line 102 has its opposite end connected to the priming connection of the centrifugal pump 82.

In order to facilitate the priming of the centrifugal pump 82, the outlet line 88 is provided with a shut-ofl valve 106. When it is desired to prime the pump 82, the suction pump 98 is actuated and the shut-off valve 106 closed and the valve 104 opened. This will result in the drawing of all air out of the suction line 84 and the pump 82 and that portion of the outlet line 88 between the pump 82 and the shut-off valve 106.

Inasmuch as the suction head 86 will be under water, the Withdrawal of all air from the suction line 84 and the centrifugal pump 82 will result in the drawing in of water into the suction line 84, the centrifugal pump 82 and the air separator and equalizer 10. After all air has been removed from the system, the valve 104 is closed and the valve 106 opened with the simultaneous starting of the centrifugal pump 82. The pump 82 being properly primed, the dredging equipment is now ready for operation.

In view of the foregoing, it will be seen that there has been illustrated and described a suitable attachment for dredges which may be utilized not only for the removal of air from dredged materials passing into a centrifugal pump of the dredging equipment to prevent the centrifugal pump from being air bound, but will also effectively equalize the load on the centrifugal pump and permit the priming of the same without the use of an auxiliary suction pump.

From the foregoing, the construction and operation of the device will be readily understood and further ex plan ation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the in vention to the exact construction shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

What is claimed as new is as follows:

1. An air separator for hydraulice dredges comprising an elongated chamber having an inlet connectable to a suction head of a dredge and an outlet connected to a 1 dredge pump, said chamber having an air space in the upper portion thereof, air evacuating means connected to said air space, separator means disposed between said air space and said air evacuating means for removing solids and liquid from air passing out of said air space, said separator means including first and second tanks, said first tank being connected to said air space, said second tank being connected to said first tank and said air evacuating means, said first tank being additionally connected to said chamber for retaining solids and liquids thereto.

2. An air separator for hydraulic dredges comprising an elongated chamber having an inlet connectable to a suction head of a dredge and an outlet connected to a dredge pump, said chamber having an air space in the upper portion thereof, air evacuating means connected to said air space, separator means disposed between said air space and said air evacuating means for removing solids and liquid from air passing out of said air space, said separator means including first and second tanks, said first tank being connected to said air space for primarily receiving air therefrom, said first tank being additionally connected to said chamber for returning solids and liquids thereto, said second tank being connected to said first tank and said air evacuating means, a float controlled valve between said first and second tanks for controlling the direct flow of fluids between said first and second tanks.

3. An air separator for hydraulic dredges comprising an elongated chamber having an inlet connectable to a suction head of a dredge and an outlet connected to a dredge pump, said chamber having an air space in the upper portion thereof, air evacuating means connected to said air space, separator means disposed between said air space and said air evacuating means for removing solids and liquids from air passing out of said air space,

said separator means including first and second tanks, said first tank being connected to said air space, said second tank being connected to said first tank and said air evacuating means, a float controlled valve between said first and second tanks for controlling the direct flow of fluids between said first and second tanks, said float controlled valve being actuated by a float mounted within said first tank.

4. An air separator for hydraulic dredges comprising an elongated chamber having an inlet connectable to a suction head of a dredge and an outlet connected to a dredge pump, said chamber having an air space in the upper portion thereof, air evacuating means connected to said air space, separator means disposed between said air space and said air evacuating means for removing solids and liquids from air passing out of said air space, said separator means including first and second tanks, said first tank being connected to said air space, said second tank being connected to said first tank and said air evacuating means, said first tank being normally partially filled with water, a priming line connected to said first tank below the normal water level thereof, said priming line being connected to the pump.

5. An air separator for hydraulic dredges comprising a horizontally elongated vertically extending chamber having a lower inlet connectable to a suction head of a dredge and a lower outiet spaced longitudinally from said inlet and connectable to a dredge pump, said chamber having an air space in the upper portion thereof, air evacuating means connected to said air space, said chamber being relatively narrow and having a maximum width at its top, said chamber forming an equalizing chamber for the flow of solids passing into the dredge pump to eliminate overloading.

6. An air separator for hydraulic dredges comprising a horizontally elongated vertically extending chamber having a lower inlet connectable to a suction head of a dredge and a lower outlet spaced longitudinally from said inlet and connectable to a dredge pump, said chamber being elongated in the direction of flow of water therethrough and having an air space in the upper portion thereof, said upper portion being of a saw tooth configuration to divide said air space into sections, and air evacuation means, piping connecting each of said sections to said air evacuation means.

7. An air separator for hydraulic dredges comprising a horizontally elongated vertically extending chamber having a lower inlet connectable to a suction head of a dredge and a lower outlet spaced longitudinally from said inlet and connectable to a dredge pump, said chamber having an air space in the upper portion thereof, air evacuating means connected to said air space, said chamher being relatively narrow and having a maximum width at its top, said chamber forming an equalizing chamber for the flow of solids passing into the dredge pump to eliminate overloading, said upper portion being of a saw tooth configuration to divide said air space into sections.

References Cited in the file of this patent UNITED STATES PATENTS 568,145 Sanderson Sept. 22, 1896 2,083,582 Taylor et a1 June 15, 1937 2,318,251 Moore May 4, 1943 2,666,671 Kimmerle Jan. 19, 1954 FOREIGN PATENTS 793,407 France Jan. 24, 1936

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