Patent Application
20150184661
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.
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.
The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, the drawings show embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
In the drawings:
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 in
The pumping system 100 comprises a first (or main) pump 102 at the higher elevation and a second (or auxiliary) pump 104 at the lower elevation. The first pump 102 has a first-pump suction port 102s and a first-pump discharge port 102d, both of which are at the higher elevation. The second pump 104 has a second-pump suction port 104s and a second-pump discharge port 104d, both of which are at the low elevation. The second-pump discharge port 104d is in fluid communication with the first-pump suction port 102s. In some embodiments of the pumping system 100, the first pump 102 has a first-pump efficiency and the second pump 104 has 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 system 100, the first pump 102 is a fire pump, the second pump 104 is a submersible hydraulic driven pump and the first-pump suction port 102s is directly connected to the second-pump discharge port 104d by a lay-flat hose 103. In other embodiments, the second pump 104 may be a floating hydraulically driven submersible pump. In still other embodiments, the second pump 104 may be an electrically driven submersible pump. In even other embodiments, the second pump 104 may be paired with a third pump (see,
The pumping system 100 has a variable speed driver 106 operatively coupled to the first pump 102. In some embodiments, the variable speed driver 106 may be a diesel engine operatively coupled to the first pump 102 is by a gear assembly 108.
A load sensing hydrostatic drive system 110 is operatively coupled to the variable speed driver 106 and to the second pump 104. The load sensing hydrostatic drive system 110 is configured to maintain a net positive suction head at the first-pump suction port 102s sufficient to prevent cavitation in the first pump 102 when the variable-speed driver 106 operates at any speed of a plurality of speeds across a wide range of flows. Suggestedly, the variable-speed driver 106 operates 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 system 100, the load sensing hydrostatic drive system 110 comprises at least one hydraulic pump 112 in fluid communication with a hydraulic motor 114 and a load sensing controller 116. The hydraulic pump 112 may be operatively coupled to the variable-speed driver 106 by the gear assembly 108 and the hydraulic motor 114 may be in fluid communication with the second pump 104.
A representative schematic for a load sensing hydrostatic drive system manufactured by HYDRA-TECH Pumps, Nesquehoning, Pa. for dual submersible pumps is shown in
In some of the foregoing embodiments of the pumping system 100, the components may be assembled in a configuration mountable on a mobile platform.
Referring to
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.
