IN-LINE JET PUMPS AND METHODS OF USE

Abstract

A jet pump comprising (A) a housing which defines at least a suction chamber, a suction inlet and a suction outlet; (B) a nozzle assembly disposed within the housing which nozzle assembly is sized and configured to receive at least a pressurized fluid and eject the pressurized fluid as a fluid flow into a portion of the suction chamber; and (C) a discharge conduit extending from the suction outlet away from the suction chamber, the discharge conduit being configured for fluid communication with the suction chamber and being disposed to receive the fluid flow from the nozzle assembly, wherein the discharge conduit defines at least a first inner diameter along a portion of its length and a second inner diameter along another portion of its length, the first inner diameter being less than the second inner diameter. The housing is configured so that the suction inlet provides a flow of suctioned material into the suction chamber which has a predominant direction of flow of suctioned material which is substantially parallel to a predominant direction of flow of the fluid flow from the nozzle assembly when the jet pump is in use.

Description

FIELD OF THE INVENTION

This invention relates generally to hydraulic nonmechanical pumping devices for transferring material, and specifically, to jet pumps for moving solid, semi-solid, slurried and/or liquid materials, as well as related methods.

BACKGROUND

When materials such as silts, sand and/or mud located at the bottoms of water bodies need to be removed, the equipment for accomplishing the removal is typically massive, heavy and difficult to maneuver. Therefore, a need exists for an apparatus of relatively small dimensions and lighter weight which can be manipulated in areas which present logistical problems for larger equipment such as drag lines, large excavators, and the like.

SUMMARY OF THE INVENTION

The present inventions meet this need, amongst others by providing an in-line jet pump for suctioning material, which can be attached to an arm of a piece of equipment such as a backhoe and which can be manipulated so that the suction inlet is in very close proximity to the material to be suctioned. The novel configuration of the in-line jet pump of this invention enables close-in work in such locations as, for example, marinas, boat slips and small sediment ponds.

The present invention provides a jet pump assembly comprising: (A) a housing which defines at least a suction chamber, a suction inlet and a suction outlet; (B) a nozzle assembly disposed within the housing which nozzle assembly is sized and configured to receive at least a pressurized fluid and eject the pressurized fluid as a fluid flow into a portion of the suction chamber; and (C) a discharge conduit extending from the suction outlet away from the suction chamber. The discharge conduit is configured for fluid communication with the suction chamber and is disposed to receive the fluid flow from the nozzle assembly. The discharge conduit defines at least a first inner diameter along a portion of its length and a second inner diameter along another portion of its length, the first inner diameter being less than the second inner diameter. The housing is configured so that the suction inlet provides a flow of suctioned material into the suction chamber which has a predominant direction of flow of suctioned material which is substantially parallel to a predominant direction of flow of the fluid flow from the nozzle assembly when the jet pump is in use.

By predominant direction of flow of the suctioned material it is to be understood that most of the suctioned material moves or flows into the jet pump through the suction inlet in one general direction. By predominant direction of flow of the fluid flow it is to be understood that most of the pressurized fluid, as it leaves the nozzle assembly as a fluid flow, moves or flows into and through a portion of the suction chamber in one general direction. By substantially parallel it is meant that the predominant direction of flow of the suctioned material and the predominant direction of flow of the fluid flow are parallel to each other within the pathways of movement of the respective suctioned material and fluid through the jet pump so that the parallel nature of the directions of flow is maintained with very little deviation.

Another embodiment of the invention provides a nozzle assembly which is sized and configured to receive the pressurized fluid and an gas and to eject the pressurized fluid as a fluid flow into the suction chamber while feeding the gas into proximity with the periphery of the fluid flow. Pursuant to another embodiment of the invention, the gas is air. In another embodiment of the invention the gas is an inert gas. Without being bound by theory, it is believed that the fluid flow (or liquid jet) created by passage of pressurized fluid through the nozzle assembly has minimal deflection of direction of flow as it exits the nozzle assembly because of an a gas bearing surrounding the liquid jet. Consequently, the in-line jet pump has improved efficiency and load capacity.

Another embodiment this invention provides a jet pump which is sized and configured so that, during use of the assembly to suction solids-containing material, the rate of movement of the suctioned material is maximized. While performance of the jet pump is greatly impacted by the character of the material to be suctioned, under certain conditions, where the material to be suctioned is a slurry of a solid and a liquid such as water, in an embodiment of the invention, the rate of movement of suctioned material is at least about 50 tons (4.5×10⁴ kg) per hour when the second inner diameter of the discharge conduit is about 4 inches (10.2 cm), the first inner diameter of the discharge conduit is about 3 inches (7.6 cm), the diameter of the nozzle assembly at the point of ejection of the pressurized fluid is about 0.625 inches (1.59 cm), pressurized fluid pressure is about 150 psi (1034 kPa), and the flow rate of the pressurized fluid is about 140 gallons (530 L) per minute. In another embodiment of the invention, the rate of movement of suctioned material is at least about 100 tons (9.1×10⁴) kg) per hour when the second inner diameter of the discharge conduit is about 6 inches (15.24 cm), the first inner diameter of the discharge conduit is about 4 inches (10.2 cm), the diameter of the nozzle assembly at the point of ejection of the pressurized fluid is about 0.875 inch (2.22 cm), the pressurized fluid pressure is about 150 psi (1034 kPa), and the flow rate of the pressurized fluid is about 280 gallons (1060 L) per minute.

In order to more readily provide access to material to be suctioned, which is often in somewhat inconvenient locations, in an embodiment of this invention, components of the jet pump are attached to or integral with an end of a excavator arm. In one embodiment of the invention the housing, the discharge conduit and a pressurized fluid supply conduit for supplying the pressurized fluid to the nozzle assembly are attached to or integral with an arm of an excavator so that the suction inlet is positioned in proximity to an end of the arm. In another embodiment a gas supply conduit for supplying the gas to the nozzle assembly is also attached to or integral with an arm of an excavator so that the suction inlet is positioned in proximity to an end of the arm. By the term excavator, it is to be understood that excavator can encompass a number of types of excavation equipment having articulated arms, such as, but not limited to, backhoes, track hoes, ditch witches, mini-excavators, drag lines and the like.

An embodiment of the invention provides that the housing comprises a pipe which pipe has an imaginary center line which is co-linear with an imaginary center line of the discharge conduit.

An embodiment of the invention provides a method of moving material comprising: (1) injecting a motive fluid as a fluid flow from a nozzle assembly into a housing which defines at least a suction chamber, a suction outlet, and a suction inlet, the suction inlet being configured for fluid communication with a material to be suctioned, so as to form a vacuum at the suction inlet; (2) placing the suction inlet of the housing in proximity to the material to be suctioned so that a flow of suctioned material through the suction inlet of the housing has a predominant direction of flow into the suction chamber which is substantially parallel to a predominant direction of flow of the fluid flow from the nozzle assembly; and (3) directing the flow of suctioned material and fluid flow into a discharge conduit extending from the suction outlet away from the suction chamber, the discharge conduit being configured for fluid communication with the suction chamber and being disposed to receive the fluid flow from the nozzle assembly. The discharge conduit defines at least a first inner diameter along a portion of its length and a second inner diameter along another portion of its length, the first inner diameter being less than the second inner diameter.

In yet another embodiment of the invention the method further comprises feeding a gas to the nozzle assembly in proximity to the periphery of the fluid flow so that the fluid flow is surrounded by the gas. In one embodiment the gas is air and in another embodiment the gas is an inert gas.

The methods of this invention provide that the nozzle assembly and housing are sized and configured so that, during use to suction solids-containing material, in an embodiment of the invention the rate of movement of suctioned material is at least about 50 tons (4.5×10⁴ kg) per hour when the second inner diameter of the discharge conduit is about 4 inches (10.2 cm), the first inner diameter of the discharge conduit is about 3 inches (7.6 cm), the diameter of the nozzle assembly at the point of ejection of the pressurized fluid is about 0.625 inches (1.59 cm), pressurized fluid pressure is about 150 psi (1034 kPa), and the flow rate of the pressurized fluid is about 140 gallons (530 L) per minute. Another embodiment of a method of this invention provides that the nozzle assembly and housing are sized and configured so that, during use to suction solids-containing material, the rate of movement of suctioned material is at least about 100 tons (9.1×10⁴) kg) per hour when the second inner diameter of the discharge conduit is about 6 inches (15.24 cm), the first inner diameter of the discharge conduit is about 4 inches (10.2 cm), the diameter of the nozzle assembly at the point of ejection of the pressurized fluid is about 0.875 inch (2.22 cm), the pressurized fluid pressure is about 150 psi (1034 kPa), and the flow rate of the pressurized fluid is about 280 gallons (1060 L) per minute.

In an embodiment of the invention a method provides that the housing, the discharge conduit and a motive fluid supply conduit for supplying the motive fluid to the nozzle assembly are attached to or integral with an arm of an excavator so that the suction inlet is positioned in proximity to an end of the arm. In another embodiment of the invention the housing, the discharge conduit, a motive fluid supply conduit for supplying the motive fluid to the nozzle assembly and a gas supply conduit for supplying the gas to the nozzle assembly are attached to or integral with an arm of an excavator so that the suction inlet is positioned in proximity to an end of the arm.

In another embodiment of the invention a method provides that the housing comprises a pipe which has an imaginary center line which is co-linear with an imaginary center line of the discharge conduit.

In further embodiments of the methods of this invention, the nozzle assembly is disposed within the housing.

Another embodiment of the invention provides a suction system comprising: (I) a jet pump comprising: (A) a housing which defines at least a suction chamber, a suction inlet and a suction outlet; (B) a nozzle assembly disposed within the housing which nozzle assembly is sized and configured to receive at least a pressurized fluid and eject the pressurized fluid as a fluid flow into a portion of the suction chamber; and (C) a discharge conduit extending from the suction outlet away from the suction chamber, the discharge conduit being configured for fluid communication with the suction chamber and being disposed to receive the fluid flow from the nozzle assembly, wherein the discharge conduit defines at least a first inner diameter along a portion of its length and a second inner diameter along another portion of its length, the first inner diameter being less than the second inner diameter; wherein the housing is configured so that the suction inlet provides a flow of suctioned material into the suction chamber which has a predominant direction of flow of suctioned material which is substantially parallel to a predominant direction of flow of the fluid flow from the nozzle assembly when the jet pump is in use; and (II) control means for controlling at least the position of the suction inlet relative to a material to be suctioned.

Embodiments of the invention also include a system wherein the nozzle assembly is sized and configured to receive the a pressurized fluid and a gas and eject the pressurized fluid as a fluid flow into the suction chamber while feeding the gas into proximity with the periphery of the fluid flow and wherein the control means is configured to control alignment of (a) the discharge conduit, (b) a pressurized fluid supply conduit for supplying pressurized fluid to the nozzle assembly and (c) a gas supply conduit for supplying the gas to the nozzle assembly; whereby (a), (b) and (c) are maintained in a substantially close-fitting relationship while the system is in use. In an embodiment of the invention the control means is comprised of a mechanical arm affixed to or integral with the discharge conduit and/or the jet pump.

The phrase, close-fitting relationship, is understood to mean that selected components of the suction system such as, the discharge conduit, the pressurized fluid supply conduit and the gas supply conduit are attached to each other and/or attached to or integral with a device or structure serving as the control means. In this way, the selected components are moved about or manipulated as a unit. Maintaining a close-fitting relationship among the selected components together with the jet pump, permits unimpeded movement of the suction inlet. This avoids problems of poor positioning when, for example, the pressurized fluid supply conduit may become bound-up or impinged during use of the suction system.

The various embodiments and features of this invention will now become apparent from the following detailed description, the accompanying drawings and the appended claims.

SUMMARY OF THE FIGURES

FIG. 1 shows a side plan view in partial cross section of an embodiment of the invention.

FIG. 2 shows an end plan view of the invention shown in FIG. 1.

FIG. 3 shows a sectional side view of an embodiment of the invention.

FIG. 4 shows a simplified sectional side view of an embodiment of the invention.

Like numbers and/or letters in the various figures are used to refer to like parts or components within the group of figures.

DETAILED DESCRIPTION OF THE INVENTION

It will now be appreciated that, while specific embodiments are described hereinafter, several other applications of the presently described invention may be contemplated by those of skill in the art in view of this disclosure. For example, while the accompanying drawings illustrate the in-line jet pump of this invention as used for suctioning operations, the jet pump may be used for virtually any application in which solid particulate matter, or a slurry comprised of such matter, must be moved from one location to another. In each of the above examples, small batch operations as well as large commercial batch, semi-continuous and continuous operations are possible using pumping methods and systems of this invention.

Referring now to the accompanying figures, FIG. 1 illustrates an embodiment of the jet pump enlarged, but not to scale. A housing 10 is shown to comprise at least a suction chamber 12, a suction inlet 16 and a suction outlet 14. A nozzle assembly 18 is disposed within housing 10. Nozzle assembly 18 receives a pressurized fluid 20 through pressurized fluid supply conduit 40 and ejects pressurized fluid 20 as a fluid flow 22, shown here as a liquid flow 22, into a portion of suction chamber 12. Nozzle assembly 18 also receives a gas 46 and feeds gas 46 into proximity with the periphery of fluid flow 22 as gas flow 24. It is believed that fluid flow (or liquid jet) 22, created by passage of pressurized fluid 20 through nozzle assembly 18, has minimal deflection of direction of flow as fluid flow 22 exits nozzle assembly 18 because of a gas bearing, shown as gas flow 24, surrounding fluid flow 22.

The jet pump is configured to provide nozzle assembly 18 to be disposed within housing 10 and thus intermediate between suction inlet 16 and suction outlet 14. This means that all suctioned material M flows around nozzle assembly 18 in passing through housing 10 and into discharge conduit 26.

Gas 46 is supplied to nozzle assembly 18 via gas supply conduit 42. In an embodiment of the invention, the gas is air. In yet another embodiment of the invention the gas is an inert gas. The gas employed in the jet pump and methods of this invention will preferably be under no more than atmospheric pressure, to reduce risk of hazardous operations and extra cost. The gas preferably will be an inert gas, e.g., nitrogen or argon, when the solid, fluid, liquid or other material being suctioned could be volatile in the presence of certain atmospheric gases, e.g., oxygen. When such volatility is not an issue, the gas employed will be most conveniently atmospheric air.

Pressurized fluid 20 is comprised of motive fluid, shown as a liquid, i.e., water, which is provided from motive fluid tank 34, although many other configurations for supplying the fluid are with the scope of this disclosure. For example, the source of fluid might be a recirculation tank, or water from some naturally occurring body of water like a pond, stream or lake. Pump P is typically a centrifugal pump for pressurizing the fluid as a liquid supplied to nozzle assembly 18, but pump P can be any kind of pumping means, such as a positive displacement pump or even another jet pump.

A discharge conduit 26, configured for fluid communication with suction chamber 12 through suction outlet 14, is disposed to receive fluid flow 22 and suctioned material 28,28. Discharge conduit 26 extends from suction outlet 14 and defines a first inner diameter D1 which is less than a second inner diameter D2. The narrow portion of discharge conduit 26 provides a venturi-like effect so that a vacuum is formed at least at suction inlet 16. Material M, shown as triangular shapes 28,28 is suctioned into housing 10 though suction inlet 16. Housing 10 is so configured that a flow of suctioned material 28,28 has a predominant direction of material flow 36 which is substantially parallel to a predominant direction of flow of the fluid flow 22 from nozzle assembly 18. Direction of fluid flow, shown as arrow 38, is substantially parallel to direction of material flow 36. Fluid flow 22 is, of course, three dimensional and when directions of flow (both fluid flow and matter flow) are indicated to be parallel or substantially parallel it is to be understood that the directions of flow are parallel in multiple planes. In particular the directions of flow are parallel at least in multiple planes which planes are offset to each other.

FIG. 2 depicts a cross-sectional view of the jet pump when viewed from the perspective of suction inlet 16. Nozzle assembly 18 is seen to comprise pressurized fluid supply conduit 40 which contains pressurized fluid 20 and also gas supply conduit 42 which contains gas flow 24.

FIG. 3 shows an embodiment of the invention wherein housing 10, with nozzle assembly 18 disposed therein, discharge conduit 26, pressurized fluid supply conduit 40 and gas supply conduit 42 are attached to an arm 32 of an excavator (not shown) at end 44. In this embodiment of the invention, arm 32 provides control means for controlling at least the position of suction inlet 16 relative to material M to be suctioned.

Attachment of housing 10, discharge conduit 26, pressurized fluid supply conduit 40 and gas supply conduit 42 is effected by use of attachment straps 30,30 though it is to be understood that attachment can be accomplished in some other manner, such as by having the components of the jet pump assembly configured integrally with an excavator arm. Though arm 32 will typically be used, any suitable articulating device can be employed.

Pressurized fluid supply conduit 40 and gas supply conduit 42 are configured to be somewhat flexible, for example, by being constructed of a material which is strong enough to maintain its integrity under adverse suction conditions while maintaining sufficient flexibility to adjust to positioning and re-positioning of the excavator arm.

The attachment of the jet pump to the excavator arm works surprisingly well to position the suction inlet in very close proximity to the material to be suctioned in order to capture a degree of versatility and ease of movement heretofore unknown in the industry. Because there is no long suction intake line, having the jet pump assembly attached to the excavator arm also provides savings in construction costs and adaptability to maneuver in confined spaces. The sizing of the conduits of the invention will vary depending on the particulate size of the material to be suctioned and the rate at which the material needs to be removed.

It is contemplated that a small excavator, with jet pump assembly attached could be readily supported on a suitable flotation device, such as a small barge, to further extend the reach, and therefore the usefulness, of the invention. A particularly desirable use for the invention is for removing silt and clay build up in boat slips and marinas, where larger, bulkier equipment would be unsuitable.

FIG. 4 is a sectional view along a longitudinal axis of housing 10 and discharge conduit 26 showing housing 10 as a pipe having an imaginary center line X which is co-linear with an imaginary center line Y of discharge conduit 26.

Control means for controlling at least the position of the suction inlet relative to a material to be suctioned may comprise any number of devices or apparatuses capable of controlling the position of the suction inlet. Suitable, non-limiting, control means includes mechanical arms of excavators (with or without a bucket at the end of the arm), mechanical arms of back hoes, mechanical arms of drag lines, mechanical arms of mini-excavators, and the like.

EXAMPLE 1

The inline jet pump was demonstrated to have superior material-moving capabilities of a rate of movement of a slurry of sand, silt and water of at least about 50 tons (4.5×10⁴ kg) per hour when the second inner diameter of the discharge conduit was about 4 inches (10.2 cm), the first inner diameter of the discharge conduit was about 3 inches (7.6 cm), the diameter of the nozzle assembly at the point of ejection of the pressurized fluid was about 0.625 inches (1.59 cm), pressurized fluid pressure was about 150 psi (1034 kPa), and the flow rate of the pressurized fluid was about 143 gallons (541 L) per minute.

EXAMPLE 2

Even better performance of the inline jet pump of a rate of movement of a slurry of sand, silt and water of at least about 100 tons (9.1×10⁴) kg) per hour was attained when the second inner diameter of the discharge conduit was about 6 inches (15.24 cm), the first inner diameter of the discharge conduit was about 4 inches (10.2 cm), the diameter of the nozzle assembly at the point of ejection of the pressurized fluid was about 0.875 inch (2.22 cm), the pressurized fluid pressure was about 150 psi (1034 kPa), and the flow rate of the pressurized fluid was about 280 gallons (1060 L) per minute.

The present invention can be used in any application requiring significant suction effect on solid material in a liquid or gaseous environment. The dimensions of the various component parts of jet pumps and systems of this invention may vary depending upon the circumstances in which the jet pump or system will be employed, so long as the dimensions permit the components to function as described herein. Except where specifically noted otherwise herein, the component parts may be fabricated from a wide variety of materials, the selection of which will depend upon the circumstances in which the device will be employed. Preferably, metals, metal alloys or resilient plastics, for example, will be employed to insure that points of mechanical contact or abrasive wear in the systems and jet pumps will be resilient enough to withstand the forces placed upon them during jet pump operation.

Except as may be expressly otherwise indicated, the article “a” or “an” if and as used herein is not intended to limit, and should not be construed as limiting, a claim to a single element to which the article refers. Rather, the article “a” or “an” if and as used herein is intended to cover one or more such elements, unless the text expressly indicates otherwise.

It should be appreciated that, while specific embodiments are described herein, several other applications of the presently described invention may be contemplated by those of skill in the art in view of this disclosure. Accordingly, the scope of this invention is not limited to the specific embodiments described in detail herein. Rather, what is intended to be covered is as set forth in the ensuing claims and the equivalents thereof permitted as a matter of law. As used in this specification, means-plus-function clauses, if any, are intended to cover the structures described herein as performing the cited function and not only structural equivalents but also equivalent structures.

Claims

1. A jet pump comprising: wherein the housing is configured so that the suction inlet provides a flow of suctioned material into the suction chamber which has a predominant direction of flow of suctioned material which is substantially parallel to a predominant direction of flow of the fluid flow from the nozzle assembly when the jet pump is in use.

(A) a housing which defines at least a suction chamber, a suction inlet and a suction outlet;

(B) a nozzle assembly disposed within the housing which nozzle assembly is sized and configured to receive at least a pressurized fluid and eject the pressurized fluid as a fluid flow into a portion of the suction chamber; and

(C) a discharge conduit extending from the suction outlet away from the suction chamber, the discharge conduit being configured for fluid communication with the suction chamber and being disposed to receive the fluid flow from the nozzle assembly, wherein the discharge conduit defines at least a first inner diameter along a portion of its length and a second inner diameter along another portion of its length, the first inner diameter being less than the second inner diameter;

2. The jet pump according to claim 1 wherein the nozzle assembly is sized and configured to receive the pressurized fluid and a gas and eject the pressurized fluid as a fluid flow into the suction chamber while feeding the gas into proximity with the periphery of the fluid flow.

3. The jet pump according to claim 2 wherein the gas is air or an inert gas.

4. The jet pump according to claim 2 wherein the nozzle assembly and housing are sized and configured so that, during use of the jet pump to suction solids-containing material, the fluid flow and suctioned solids-containing material form a mixture and wherein the rate of movement of suctioned material is at least about 50 tons (4.5×104 kg) per hour when the second inner diameter of the discharge conduit is about 4 inches (10.2 cm), the first inner diameter of the discharge conduit is about 3 inches (7.6 cm), the diameter of the nozzle assembly at the point of ejection of the pressurized fluid is about 0.625 inch (1.59 cm), the pressurized fluid pressure is about 150 psi (1034 kPa), and the flow rate of the pressurized fluid is about 140 gallons (530 L) per minute.

5. The jet pump according to claim 1 wherein the housing, the discharge conduit and a pressurized fluid supply conduit for supplying the pressurized fluid to the nozzle assembly are attached to or integral with an arm of an excavator so that the suction inlet is positioned in proximity to an end of the arm.

6. The jet pump according to claim 2 wherein the housing, the discharge conduit, a pressurized fluid supply conduit for supplying the pressurized fluid to the nozzle assembly and a gas supply conduit for supplying the gas to the nozzle assembly are attached to or integral with an arm of an excavator so that the suction inlet is positioned in proximity to an end of the arm.

7. The jet pump according to claim 1 wherein the housing comprises a pipe which pipe has an imaginary center line which is co-linear with an imaginary center line of the discharge conduit.

8. The jet pump according to claim 1 wherein the nozzle assembly is disposed within the housing.

9. A method of moving material comprising:

(1) injecting a motive fluid as a fluid flow from a nozzle assembly into a housing which defines at least a suction chamber, a suction outlet, and a suction inlet, the suction inlet being configured for fluid communication with a material to be suctioned, so as to form a vacuum at the suction inlet;

(2) placing the suction inlet of the housing in proximity to the material to be suctioned so that a flow of suctioned material through the suction inlet of the housing has a predominant direction of flow into the suction chamber which is substantially parallel to a predominant direction of flow of the fluid flow from the nozzle assembly; and

(3) directing the suctioned material and fluid flow into a discharge conduit extending from the suction outlet away from the suction chamber, the discharge conduit being configured for fluid communication with the suction chamber and being disposed to receive the fluid flow from the nozzle assembly, wherein the discharge conduit defines at least a first inner diameter along a portion of its length and a second inner diameter along another portion of its length, the first inner diameter being less than the second inner diameter.

10. The method according to claim 9 further comprising feeding a gas to the nozzle assembly in proximity to the periphery of the fluid flow so that the fluid flow is surrounded by the gas.

11. The method according to claim 10 wherein the gas is air or an inert gas.

12. The method according to claim 10 wherein the nozzle assembly and housing are sized and configured so that, during use of the assembly to suction solids-containing material, the fluid flow and suctioned solids-containing material form a mixture the rate and wherein the rate of movement of suctioned material is at least about 100 tons (9.1×104) kg) per hour when the second inner diameter of the discharge conduit is about 6 inches (15.24 cm), the first inner diameter of the discharge conduit is about 4 inches (10.2 cm), the diameter of the nozzle assembly at the point of ejection of the pressurized fluid is about 0.875 inch (2.22 cm), the pressurized fluid pressure is about 150 psi (1034 kPa), and the flow rate of the pressurized fluid is about 280 gallons (1060 L) per minute.

13. The method according to claim 9 wherein the housing, the discharge conduit and a motive fluid supply conduit for supplying the motive fluid to the nozzle assembly are attached to or integral with an arm of an excavator so that the suction inlet is positioned in proximity to an end of the arm.

14. The method according to claim 10 wherein the housing, the discharge conduit, a motive fluid supply conduit for supplying the motive fluid to the nozzle assembly and a gas supply conduit for supplying the gas to the nozzle assembly are attached to or integral with an arm of an excavator so that the suction inlet is positioned in proximity to an end of the arm.

15. The method according to claim 9 wherein the housing comprises a pipe which has an imaginary center line which is co-linear with an imaginary center line of the discharge conduit.

16. The method according to claim 9 wherein the nozzle assembly is disposed within the housing.

17. A suction system comprising:

(I) a jet pump comprising: (A) a housing which defines at least a suction chamber, a suction inlet and a suction outlet; (B) a nozzle assembly disposed within the housing which nozzle assembly is sized and configured to receive at least a pressurized fluid and eject the pressurized fluid as a fluid flow into a portion of the suction chamber; and (C) a discharge conduit extending from the suction outlet away from the suction chamber, the discharge conduit being configured for fluid communication with the suction chamber and being disposed to receive the fluid flow from the nozzle assembly, wherein the discharge conduit defines at least a first inner diameter along a portion of its length and a second inner diameter along another portion of its length, the first inner diameter being less than the second inner diameter; wherein the housing is configured so that the suction inlet provides a flow of suctioned material into the suction chamber which has a predominant direction of flow of suctioned material which is substantially parallel to a predominant direction of flow of the fluid flow from the nozzle assembly when the jet pump is in use;

(II) control means for controlling at least the position of the suction inlet relative to a material to be suctioned.

18. The system according to claim 17 wherein the nozzle assembly is sized and configured to receive the pressurized fluid and a gas and eject the pressurized fluid as a fluid flow into the suction chamber while feeding the gas into proximity with the periphery of the fluid flow and wherein the control means is configured to control alignment of (a) the discharge conduit, (b) a pressurized fluid supply conduit for supplying pressurized fluid to the nozzle assembly and (c) a gas supply conduit for supplying the gas to the nozzle assembly; whereby (a), (b) and (c) are maintained in a substantially close-fitting relationship while the system is in use.

19. The system according to claim 17 wherein the control means is comprised of a mechanical arm affixed to or integral with the discharge conduit and/or the jet pump.

20. The system according to claim 17 wherein the housing comprises a pipe which pipe has an imaginary center line which is co-linear with an imaginary center line of the discharge conduit.

21. The system according to claim 17 wherein the nozzle assembly is disposed within the housing.