Transportable High Vertical-Lift Emergency Water Pumping System

A transportable high vertical-lift emergency water pumping system moves emergency water from a water source at a low elevation to a higher elevation. The pumping system has a first pump having a first-pump suction port at the higher elevation and a second pump having a second-pump suction port at the low elevation and a second-pump discharge port in fluid communication with the first-pump suction port. A variable speed driver is operatively coupled to the first pump. A load sensing hydrostatic drive system is operatively coupled to the variable speed driver and to the second pump. The load sensing hydrostatic drive system is configured to maintain a minimum net positive suction head at the first-pump suction port sufficient to prevent cavitation in the first pump when the variable-speed driver operates at any speed of a plurality of speeds across a range of flows.

BACKGROUND OF THE INVENTION

The present invention relates to a transportable water pumping system for emergency applications. More particularly, the present invention relates to high vertical-lift water pumping systems able to moving water from a water source such as a lake or river at a low elevation to a higher elevation for emergency use in situations such as fire fighting or cooling after a disaster has taken out all power and support infrastructure.

Often, the main way to extinguish a fire is to spray the base of the fire with massive volumes of water to asphyxiate the flames and cool the combustible material and the surrounding area Water for fighting a fire may be accessed from various sources, such as from a pressurized fire hydrant, pumped from water sources such as lakes or rivers, or delivered by tanker truck. In instances when the source of water is a body of water in a location with difficult access, it may not be practical to place pumping equipment entirely proximal to the source of water.

Accordingly, there is a need in certain emergency situations for a transportable high vertical-lift water pumping system able to draw water from a water source at a low elevation to extinguishing fires at a higher elevation or to cool structures at a higher elevation containing hazardous materials.

BRIEF SUMMARY OF THE INVENTION

Briefly stated, one embodiment of the present invention is directed to a transportable high vertical-lift emergency water pumping system for moving emergency water from a water source at a low elevation to a higher elevation. The pumping system has a first pump having a first-pump suction port at the higher elevation and a second pump having a second-pump suction port at the low elevation and a second-pump discharge port in fluid communication with the first-pump suction port. A variable speed driver operatively couples to the first pump. A load sensing hydrostatic drive system is operatively coupled to the variable speed driver and to the second pump. The load sensing hydrostatic drive system is configured to maintain a minimum net positive suction head at the first-pump suction port sufficient to prevent cavitation in the first pump when the variable-speed driver operates at any speed within a range of flows.

Another embodiment of the present invention is directed to a method for moving emergency water from a water source at a low elevation to a higher elevation relative to the water source. The method comprises the following steps: (i) drawing water from the water source into a suction port of a hydraulically driven submersible pump in the water source; (ii) discharging the water from a discharge port of the hydraulically driven submersible pump into a lay-flat hose connecting the discharge port of the hydraulically driven submersible pump to a suction port of a fire pump at the higher elevation; and (iii) maintaining a minimum net positive suction head at the fire-pump suction port sufficient to prevent cavitation in the fire pump when the water is discharged from a discharge port of the fire pump at any flow rate within a range of flow rates.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

As used in the description of the invention and the appended claims, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The words “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Although the words first, second, etc., are used herein to describe various elements, these elements should not be limited by these words. These words are only used to distinguish one element from another. For example, a first pump could be termed a second pump, and, similarly, a second pump could be termed a first pump, without departing from the scope of the present invention.

The following description is directed towards various embodiments of a pumping system in accordance with the present invention.

Referring to the drawings in detail, where like numerals indicate like elements throughout, there is shown inFIG. 1a first preferred embodiment of the a transportable high vertical-lift emergency water pumping system, generally designated100, and hereinafter referred to as the “pumping system”100in accordance with the present invention. The pumping system100is for moving emergency water from a water source at a low elevation such as a lake or river to a higher elevation at which structure requiring the emergency water is located. Various embodiments of the present invention can be configured to accommodate a wide range of differences in elevation such as about 35 ft to 150 ft. However, the difference in elevation that some embodiments of the present invention can accommodate is not limited to the range of about 35 ft to 150 ft.

The pumping system100comprises a first (or main) pump102at the higher elevation and a second (or auxiliary) pump104at the lower elevation. The first pump102has a first-pump suction port102sand a first-pump discharge port102d,both of which are at the higher elevation. The second pump104has a second-pump suction port104sand a second-pump discharge port104d,both of which are at the low elevation. The second-pump discharge port104dis in fluid communication with the first-pump suction port102s.In some embodiments of the pumping system100, the first pump102has a first-pump efficiency and the second pump104has a second-pump efficiency less than the first-pump efficiency. Suggestedly, the first pump has an efficiency of at least about 60%, desirably 70% or more, and preferably between about 70 to 75, for a head about 150 to 250 psi and a flow of about 500 to 3000 gallons per minute and the second pump has an efficiency at least about 50%.

In some embodiments of the pumping system100, the first pump102is a fire pump, the second pump104is a submersible hydraulic driven pump and the first-pump suction port102sis directly connected to the second-pump discharge port104dby a lay-flat hose103. In other embodiments, the second pump104may be a floating hydraulically driven submersible pump. In still other embodiments, the second pump104may be an electrically driven submersible pump. In even other embodiments, the second pump104may be paired with a third pump (see,FIG. 2) having a third-pump suction port at the low elevation and a third-pump discharge port in fluid communication with the first-pump suction port102s.In some embodiments, the second and third pumps may independently be turned on or off so that either the first pump or the second pump or both the first pump and the second pump may be used to increase lift or flow capacity.

The pumping system100has a variable speed driver106operatively coupled to the first pump102. In some embodiments, the variable speed driver106may be a diesel engine operatively coupled to the first pump102is by a gear assembly108.

A load sensing hydrostatic drive system110is operatively coupled to the variable speed driver106and to the second pump104. The load sensing hydrostatic drive system110is configured to maintain a net positive suction head at the first-pump suction port102ssufficient to prevent cavitation in the first pump102when the variable-speed driver106operates at any speed of a plurality of speeds across a wide range of flows. Suggestedly, the variable-speed driver106operates at a speed of at least about 1800 rpm, desirably 2000 rpm or more, and preferably between about 1900 to 2100 rpm, for a first pump net positive suction head about 5 to 10 psi and a flow of about 500 to 3000 gallons per minute .

In some embodiments of the pumping system100, the load sensing hydrostatic drive system110comprises at least one hydraulic pump112in fluid communication with a hydraulic motor114and a load sensing controller116. The hydraulic pump112may be operatively coupled to the variable-speed driver106by the gear assembly108and the hydraulic motor114may be in fluid communication with the second pump104.

A representative schematic for a load sensing hydrostatic drive system manufactured by HYDRA-TECH Pumps, Nesquehoning, Pa. for dual submersible pumps is shown inFIG. 2. The, components in the schematic designating by the reference numbers appearing therein are identified in the following table:

In some of the foregoing embodiments of the pumping system100, the components may be assembled in a configuration mountable on a mobile platform.

Referring toFIG. 3, in use, the pumping system100moves emergency water from a water source at a low elevation to a higher elevation relative to the water source in the following manner.

In a drawing step S1, water from the water source is drawn into the suction port a hydraulically driven submersible pump in the water source.

In a discharging step S2, the drawn water is discharged from a discharge port of the hydraulically driven submersible pump into a lay-flat hose connecting the discharge port of the hydraulically driven submersible pump to a suction port of a fire pump at the higher elevation.

In a maintaining step S3, a minimum net positive suction head is maintained at the fire-pump suction port sufficient to prevent cavitation in the fire pump when the water is discharged from a discharge port of the fire pump at any of a plurality of flow rates. The net positive suction head is preferably maintained by a the load sensing hydrostatic drive system.

The foregoing detailed description of the invention has been disclosed with reference to specific embodiments. However, the disclosure is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Those skilled in the art will appreciate that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. Therefore, the disclosure is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.