US20070031265A1

US20070031265A1 - Valve and pump devices for expelling fluid from vessels

Info

Publication number: US20070031265A1
Application number: US11/161,482
Authority: US
Inventors: Gregory Cavouras
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-08-04
Filing date: 2005-08-04
Publication date: 2007-02-08
Also published as: CA2555906A1

Abstract

A pump apparatus for use with a vessel to selectively expel fluid from the vessel, the apparatus comprising a housing with an internal chamber having first and second portions, the first portion includes an inlet port and an outlet port that communicates with the outside of the vessel; a conduit connected to the inlet port and in fluid communication with the inside of the vessel; a stopper mounted within the first portion and being movable to seal and unseal the outlet port for regulating the expulsion of fluid from the chamber; a reciprocating member moveably mounted within the second portion and being dimensioned for a close fit therein, and further being connected to the stopper and having a larger exposed surface area than the stopper, such that the reciprocating member moves in a first direction in response to an increase in fluid pressure in the first portion causing the stopper to unseal the outlet port, and moves in an opposite second direction when the fluid pressure in the first portion returns to that of the resting state of the apparatus, thereby enabling the stopper to seal the outlet port; and a means for selectively increasing the fluid pressure in the first portion of the chamber to actuate the reciprocating member.

Description

BACKGROUND OF THE INVENTION

The present invention relates generally to devices for pumping fluid, and more specifically, to devices for expelling fluid from a vessel or other fluid containers, and even more specifically to pump devices for use with firefighting containers transportable by helicopter for carrying fire retardants, foams, gels or water wherein the pump devices selectively expel said fluid material from the firefighting container.
It is often desirable to expel quantities of fluid from a vessel or other fluid container having fluid therein in order to control the amount of fluid remaining in the vessel. For example, large fires are often fought using aircraft to drop fire retardants, foams, gels or water, either directly on the fire or at nearby locations to create a fire break. A very effective approach to this kind of fire fighting uses a large vessel or bucket suspended from a helicopter. Helicopters are generally used for sustained fire fighting operations because they are more versatile than fixed wing aircraft. Since a helicopter does not require a landing strip, the bucket can be filled, without landing the helicopter, at a nearby body of water or at a temporary staging area set up to maintain a supply of fire retardant fluid close to the fire by simply dunking the bucket into the source. This reduces the amount of time required between drops, which likewise reduces the time required to extinguish the fire.
The lifting capacity of any given helicopter, hence the amount of fluid the helicopter is able to carry in a bucket at any given time, varies with the amount of fuel in the helicopter and with the weight of other cargo on board. Accordingly, after having filled the bucket from a source, it would be desirable for the pilot to be able to expel fluid from the bucket in order to reduce the weight of the load to a desired level before lifting off with the loaded bucket, thereby being able to maximize the amount of fluid carried based on the lifting capacity of the helicopter at that particular moment.

SUMMARY OF THE INVENTION

The present invention provides valve and pump devices that are compact so that they are useable with a vessel, tank or other fluid container, such as inside a firefighting bucket, that are efficient, and that are remotely controllable, such as from the cockpit of an aircraft or the like.
Accordingly, in some embodiments of the present invention there is provided a pump device for use with a vessel for selectively expelling fluid from the vessel comprising a housing defining an internal chamber having first and second portions, the second portion being larger in cross-section than the first portion and being in fluid communication with fluid in the vessel when the apparatus is operably mounted with the vessel, the first portion of the housing further including a fluid inlet port and a fluid outlet port, wherein the chamber is in fluid communication with the fluid in the vessel via the inlet port; connector means cooperating with the housing for mounting the apparatus on the vessel in a manner that the outlet port communicates with the outside of the vessel through the wall of the vessel, wherein the chamber is in fluid communication with the atmosphere via the outlet port; a stopper mounted within the first portion of the housing and being movable to seal and unseal the outlet port to regulate the expulsion of fluid from the chamber, the stopper being biased towards sealing the outlet port when apparatus is in a resting state; a piston reciprocating within the second portion and being connected to the stopper, the piston further having a larger exposed surface area than the stopper, wherein the piston moves in a direction away from the outlet port in response to an increase in fluid pressure in the first portion causing the stopper to unseal the outlet port, and moves in the opposite direction in response to the biasing force acting on the stopper when the fluid pressure in the first portion returns to that of the resting state of the apparatus, thereby enabling the stopper seal the outlet port; and a means for selectively increasing the fluid pressure in the first portion of the chamber with fluid from the vessel via the inlet port. The piston and stopper may be moveable in a linear path along the same axis. In some embodiments, the piston and stopper are moveable along the axis of the chamber. The apparatus may include a rod mounted for reciprocating movement along the axis of the chamber, and having one end connected to the stopper, and an opposite end connected to the piston. The piston may be moveable in relation to the rod, and the apparatus further includes a retainer at the opposite end and a coil spring mounted on the rod between the retainer and the piston for biasing the piston away from the retainer.
In some embodiments, the first portion of the chamber is cylindrical, and the first and second portions are coaxial. The stopper may be dimensioned to fit closely within the first portion of the chamber.
In some embodiments, the inlet port and the outlet port are substantially at a right angle to each other. The stopper may be biased by a coil spring having one end connected to the housing and the other end abutting the stopper.
In some embodiments, the means for selectively increasing the fluid pressure in the first portion comprises a duct connected to the inlet port and communicating with the fluid in the vessel, an impeller mounted for rotation within the duct, a submersible motor electrically coupled to a power source and connected to the duct for driving the impeller, and a remote switch connected to the motor for activating and deactivating the motor. Stator vanes may be included within the duct and located downstream from the impeller.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example to the accompanying drawings in which:
FIG. 1 is a medial section view of an embodiment of the present invention shown mounted in the vertical wall of a vessel or other fluid container;
FIG. 2 is a medial section view of the device in FIG. 1 shown with the outlet port in a sealed position;
FIG. 3 is a medial section view of the device in FIG. 1 shown with the outlet port in an open position;
FIG. 4 is a front elevation view of the device in FIG. 1;
FIG. 5 is a rear elevation view of the device in FIG. 1;
FIG. 6 medial section view of another embodiment of the present invention shown with the outlet port in a sealed position; and
FIG. 7 is a medial section view of the device in FIG. 6 shown with the outlet port in an open position.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention.
Referring to FIG. 1, an embodiment of the present invention is generally indicated at 10 and is shown mounted inside a vertical wall 12 of a vessel or other fluid container, adjacent the bottom 13 of the vessel. In particular, device 10 is well suited to being mounted inside a water tank or bucket of the kinds typically transported by helicopter for use in fighting fires, wherein device 10 is advantageously employed to remotely reduce the weight of the tank or bucket by expelling water therefrom to achieve a desired weight. However, the device may be used in a multitude of other applications than those discussed herein.
Referring to FIGS. 1-5, device 10 has a valve housing 20 comprising of two longitudinally aligned tubular portions 22 and 24, and defining an internal chamber having two longitudinally aligned coaxial cylinder portions or sub-chambers 26 and 28 of differing cross-sectional dimensions. Sub-chamber 28 is larger in cross-section than sub-chamber 26. At the juncture of tubular portions 22 and 24, there is defined circumferential internal shoulder 30 in the housing wall. At end 32 of the housing adjacent sub-chamber 26 is a tubular outlet port 34 that is centered on the axis 36 of the chamber, and which communicates with sub-chamber 26. The diameter of the outlet port 34 is less than the diameter of tubular portion 22, and the juncture of the two defines a shoulder 38 having a flat outer surface 40 and a tapered inner surface 42 that provides a seating and sealing surface. Outlet port 34 includes threads 44 adjacent said shoulder and a gland nut 46 cooperating with the threads for mounting the device within a bore of a vessel wall 12 (as shown in FIG. 1) such that the portion of the wall adjacent the bore is sandwiched between nut 46 and flat surface 40. While the device is described herein as being mounted inside a vessel, it is to be understood that the device may be used externally of the vessel provided that a conduit communicates fluid from the vessel to the chamber of the device for the purpose of emptying the vessel.
The housing 20 along the length of tubular portion 22 is provided with an inlet port 50 that communicates with sub-chamber 26, and which is substantially aligned at right angle to the outlet port 34. To the inlet port 50 is connected a means for selectively increasing the fluid pressure in sub-chamber 26, such as for example, an axial flow pump 54 that draws fluid from the vessel and delivers it under pressure to said sub-chamber.
Axial flow pump 54 has a tubular duct 56 that is connected to the inlet port 50 at one end and to a submersible electric motor 58 at the other end. Hence the duct communicates with sub-chamber 26. Within the duct 56 is provided an impeller 60 that is driven by the motor, and stator vanes 62 located downstream from the impeller. Preferably, each stator vane is angled from between 30 and 60 degrees to the axis 64 of the duct for disturbing fluid flow there through. Inlet openings 66 are located upstream from the impeller around the circumference of the duct 56 and enable fluid from the vessel to flow into the duct. A source of power is provided to the motor by a waterproof electrical conduit 68 that is connected to a switch (not shown) to enable an operator to selectively energize the pump, hence pressurize and unpressurize sub-chamber 26.
The internal surface of the valve housing wall adjacent shoulder 30 is further provided with a circumferential groove 70 into which is fixedly connected a circular disk 72 having a central bore 74 that is centered on the axis 36 of the chamber, and a plurality of fluid ports 76 that permit fluid flow between sub-chambers 26 and 28. The surface of the disk and the surface of shoulder within sub-chamber 28 are coplanar, and provide a seat for a piston 82 that reciprocates within sub-chamber 28.
Referring to FIGS. 2 and 3, a piston rod 84 is mounted within central bore 74 of disk 72 for reciprocating movement along the axis 36 of the chamber. One end of the rod is connected to a circular sealing stopper 90 having a tapered outer surface 92 that is complimentary to the seating and sealing surface 42 and enables the stopper 90 to seat therein to provide a fluid tight seal of the outlet port 34. The stopper 90 is biased towards the outlet port by a biasing means such as coil spring 94 that surrounds the piston rod 84 and abuts the stopper 90 and disk 72. The other end of the piston rod is connected to the piston. Accordingly, the piston, piston rod, stopper and spring comprise a valve assembly. Surfaces 96 and 98 of the stopper and the piston respectively, are each exposed to fluid pressure within the sub-chamber 26 and are referred to herein as exposed surfaces. The exposed surface area of the piston is larger than the exposed surface area of the stopper. The valve assembly moves on the principal of unequal forces that is provided by fluid pressure in sub-chamber 26 induced by the pump 54 and acting on two ‘pistons’, in effect, being the stopper 90 and piston 82. The unequal forces are achieved by using unequal, but linearly connected, piston areas within the valve, in effect, being the exposed surface areas 96 and 98. The stopper acts as the smaller of the two pistons, as well as a means of sealing the outlet port within the device. The outlet port can be closed or opened based on the energized state of the pump, which is controlled by a remote switch. When the pump is energized, the unequal forces impart a motion on the valve assembly by forcing the piston 82, having the larger exposed surface area, to move in a direction away from the outlet port, thereby causing the stopper 90 to move in that direction as well. The unequal forces overcome all resisting forces that act to keep the stopper in the closed position, such as for example suction, stiction, friction, and the biasing force of spring 94, causing the stopper to expose the outlet port and the contained liquid to be released there through. With the outlet port open, the pump forces the contained liquid through the outlet port. De-energizing the pump removes the unequal forces on the pistons, and the biasing force of spring 94 acting on the stopper repositions the stopper (and valve assembly) to a sealing state in which the stopper seals the outlet port.
The dimensions of the exposed surface areas of the stopper and piston are dependant upon the resisting forces that must be overcome in order to un-stop the outlet port. For example, variables such as the type of fluid, the depth of the fluid in the vessel, the pressure generated by the pump, the spring constant of spring 94, and the angle and size of the stators may affect the relative exposed surface areas that must be used to impart sufficient hydraulic force onto the piston 82 to move the valve assembly.
An embodiment of the present invention used to expel water from an open tank having a maximum water depth of 8.5 feet comprises spring 94 having a spring constant (k) of 0.5 lb/inch; a 28V DC pump motor drawing up to 15 Amps and driving a three bladed impeller measuring three and a quarter inches in diameter; the ratio of the exposed surface areas of the piston to the stopper being 1.5:1 or more, and preferably in the range of 1.5:1 to 4:1 (the upper end being dictated primarily by practicality due to size differences in the housing). However, it is should be understood that other combinations of parameters from those described above may be used and are within the scope of the present invention.
Referring to FIGS. 6 and 7, another embodiment of the present invention is indicated generally at 110. Device 110 is the same as device 10 in all aspects except in the valve assembly, and elements common to both will are referenced by the same numerals as in the description of device 10.
In device 110, the piston 82 includes a central bore 114 that aligns with, and is the same size as bore 74 of disk 72. The second end of the piston rod 84 is not directly connected to the piston, but rather it passes through the central bore 114 and it includes a terminal retainer disk 116 that provides an abutment for an end of a second coil spring 118 located between the retainer disk and the piston 82, thereby biasing the piston away from the terminal disk.
When system is off, the stopper 90 seals the outlet port 34 with the aid of the liquid head pressure and the biasing force of spring 94. When the system is turned on, the pump 54 is energized, pressurizing the sub-chamber 26, creating a hydraulic force on the exposed surface 98 of the piston, which is larger than the exposed surface 96 of the stopper 90. Initially, the movement of the piston is resisted by spring 114 until a point at which the hydraulic force on the piston suddenly overcomes the resisting force of said spring. Once this occurs, the resulting action is a sudden lateral “jerking” or hammer action of the piston as it builds inertia traveling to the end of its “free-play” and strikes the retainer disk 116, which action is transmitted to the valve assembly causing it to simultaneously move the stopper laterally to open the outlet port 34, thereby allowing the liquid to be pumped out of the vessel. The hammer action enables the use of a smaller piston/cylinder combination relative to the stopper than would otherwise be required in an embodiment without the hammer action (such as in device 10), in which case the hammer action is necessary to overcome suction and other sealing forces acting on the stopper 90. When system is switched off, the pump pressures stops, and the diaphragm returns to its original sealing role.
An embodiment used to expel water from an open tank having a maximum water depth of 8.5 feet comprises spring 94 and 116 having a spring constant (k) of 0.5 lb/inch; a 28V DC pump motor drawing up to 15 Amps and driving a three bladed impeller measuring three and a quarter inches in diameter; the ratio of the exposed surface areas of the piston to the stopper being 1.1:1 or more, and preferably in the range of 1.1:1 to 4:1 (the upper end being dictated primarily by practicality due to size differences in the housing). However, it is should be understood that other combinations of parameters from those described above may be used and are within the scope of the present invention.
It is to be noted that alternate means for selectively increasing the fluid pressure in sub-chamber 26 can be used, such as for example, a fluid pump communicating with sub-chamber 26 through a third port (not illustrated) independent of inlet port 50 or outlet port 34, and fluids other than the fluid to be emptied from the vessel may be used to increase the fluid pressure in sub-chamber 26 and motivate the piston 82. In such embodiments, axial flow pump 54 may be replaced by a conduit connected to the inlet port 50 and which communicates with the inside of the vessel for the purpose of emptying the vessel, and the motive force for expelling the fluid once the stopper unseals the outlet port would be provided by the head pressure of the fluid in the vessel.
While the above description and illustrations constitute preferred or alternate embodiments of the present invention, it will be appreciated that numerous variations may be made without departing from the scope of the invention, which is defined in the appended claims.

Claims

1. A valve apparatus for use with a vessel for selectively enabling the expulsion of fluid from the vessel, the apparatus comprising:

a housing defining an internal chamber having first and second portions, wherein the first portion of the housing includes a fluid inlet port that is in fluid communication with the inside of the vessel when the apparatus is operably connected to the vessel and a fluid outlet port that communicates with the outside of the vessel;

a stopper mounted within the first portion of the housing and being movable to seal and unseal the outlet port for regulating the expulsion of fluid from the chamber;

a reciprocating member moveably mounted within the second portion and being dimensioned for a close fit therein, and further being connected to the stopper and having a larger exposed surface area than the stopper, such that the reciprocating member moves in a first direction in response to an increase in fluid pressure in the first portion causing the stopper to unseal the outlet port, and moves in an opposite second direction when the fluid pressure in the first portion returns to that of the resting state of the apparatus, thereby enabling the stopper to seal the outlet port; and

a means for selectively increasing the fluid pressure in the first portion of the chamber to actuate the reciprocating member.

2. The apparatus of claim 1 wherein the reciprocating member and stopper are moveable in a linear path along the same axis.

3. The apparatus of claim 2 wherein the stopper is biased towards sealing the outlet port when the apparatus is in a resting state.

4. The apparatus of claim 3 wherein the means for increasing fluid pressure in the first portion communicates with the inlet port.

5. The apparatus of claim 4 wherein the reciprocating member and stopper are moveable along the axis of the chamber.

6. The apparatus of claim 5 further including a rod mounted for reciprocating movement along the axis of the chamber, and having one end connected to the stopper and an opposite end connected to the reciprocating member.

7. The apparatus of claim 6 wherein the reciprocating member is moveable in relation to the rod, and the apparatus further includes a retainer at the opposite end and a biasing means mounted on the rod between the retainer and the reciprocating member for biasing the reciprocating member away from the retainer.

8. The apparatus of any one of claims 6 and 7 wherein the second portion is cylindrical and the reciprocating member is a piston within the second portion.

9. The apparatus of claim 8 wherein the first portion of the chamber is cylindrical, and the first and second portions are coaxial.

10. The apparatus of claim 9 wherein the stopper is dimensioned to fit closely within the first portion of the chamber.

11. The apparatus of claim 10 wherein the inlet port and the outlet port are substantially at a right angle to each other.

12. The apparatus of claim 11 wherein the stopper is biased by a coil spring having one end connected to the housing and the other end abutting the stopper.

13. The apparatus of claim 12 wherein the ratio of the exposed surface area of the piston to the exposed surface area of the stopper is at least 1.5:1.

14. A pump apparatus for use with a vessel to selectively expel fluid from the vessel, the apparatus comprising:

a housing defining an internal chamber having first and second portions, wherein the first portion of the housing includes a fluid inlet port and a fluid outlet port that communicates with the outside of the vessel;

a conduit connected to the inlet port and in fluid communication with the inside of the vessel;

15. The apparatus of claim 14 wherein the means for increasing fluid pressure in the first portion comprises an impeller mounted for rotation within the conduit, a motor electrically coupled to a power source and connected to the impeller for rotating the impeller, and a remote switch connected to the motor for activating and deactivating the motor.

16. The apparatus of claim 15 wherein the reciprocating member and stopper are moveable in a linear path along the same axis.

17. The apparatus of claim 16 wherein the stopper is biased towards sealing the outlet port when the apparatus is in a resting state.

18. The apparatus of claim 17 wherein the reciprocating member and stopper are moveable along the axis of the chamber.

19. The apparatus of claim 18 further including a rod mounted for reciprocating movement along the axis of the chamber, and having one end connected to the stopper and an opposite end connected to the reciprocating member.

20. The apparatus of claim 19 wherein the reciprocating member is moveable in relation to the rod, and the apparatus further includes a retainer at the opposite end and a biasing means mounted on the rod between the retainer and the reciprocating member for biasing the reciprocating member away from the retainer.

21. The apparatus of any one of claims 19 and 20 wherein the second portion is cylindrical and the reciprocating member is a piston within the second portion.

22. The apparatus of claim 21 wherein the first portion of the chamber is cylindrical, and the first and second portions are coaxial.

23. The apparatus of claim 22 wherein the stopper is dimensioned to fit closely within the first portion of the chamber.

24. The apparatus of claim 23 wherein the inlet port and the outlet port are substantially at a right angle to each other.

25. The apparatus of claim 24 wherein the stopper is biased by a coil spring having one end connected to the housing and the other end abutting the stopper.

26. The apparatus of claim 25 wherein the ratio of the exposed surface area of the piston to the exposed surface area of the stopper is at least 1.5:1.

27. A pump apparatus for mounting in transportable firefighting containers for selectively expelling fluid from such container, the apparatus comprising:

a housing defining an internal chamber having first and second portions, the second portion being larger in cross-section than the first portion and being in fluid communication with fluid in the container when the apparatus is mounted in the container, the first portion of the housing further including a fluid inlet port and a fluid outlet port, wherein the chamber is in fluid communication with the fluid in the container via the inlet port;

connector means cooperating with the housing for mounting the apparatus in the container in a manner that the outlet port communicates with the outside of the container through the wall of the container, wherein the chamber is in fluid communication with the atmosphere via the outlet port;

a stopper mounted within the first portion of the housing and being movable to seal and unseal the outlet port to regulate the expulsion of fluid from the chamber;

a reciprocating member moveably mounted within the second portion and being dimensioned for a close fit therein, and further being connected to the stopper and having a larger exposed surface area than the stopper, such that the reciprocating member moves in a first direction in response to an increase in fluid pressure in the first portion causing the stopper to unseal the outlet port, and moves in an opposite second direction when the fluid pressure in the first portion returns to that of the resting state of the apparatus, thereby enabling the stopper to seal the outlet port;

a duct connected to the inlet port and communicating with the fluid in the container; and

a means for selectively increasing the fluid pressure in the first portion of the chamber to actuate the reciprocating member comprising an impeller mounted for rotation within the duct, a submersible motor electrically coupled to a power source and connected to the impeller for driving the impeller, and a remote switch connected to the motor for activating and deactivating the motor.

28. The apparatus of claim 27 wherein the reciprocating member and stopper are moveable in a linear path along the same axis.

29. The apparatus of claim 28 wherein the stopper is biased towards sealing the outlet port when the apparatus is in a resting state.

30. The apparatus of claim 29 wherein the reciprocating member and stopper are moveable along the axis of the chamber.

31. The apparatus of claim 30 further including a rod mounted for reciprocating movement along the axis of the chamber, and having one end connected to the stopper and an opposite end connected to the reciprocating member.

32. The apparatus of claim 31 wherein the reciprocating member is moveable in relation to the rod, and the apparatus further includes a retainer at the opposite end and a biasing means mounted on the rod between the retainer and the reciprocating member for biasing the reciprocating member away from the retainer.

33. The apparatus of any one of claims 31 and 32 wherein the second portion is cylindrical and the reciprocating member is a piston within the second portion.

34. The apparatus of claim 33 wherein the first portion of the chamber is cylindrical, and the first and second portions are coaxial.

35. The apparatus of claim 34 wherein the stopper is dimensioned to fit closely within the first portion of the chamber.

36. The apparatus of claim 35 wherein the inlet port and the outlet port are substantially at a right angle to each other.

37. The apparatus of claim 36 wherein the stopper is biased by a coil spring having one end connected to the housing and the other end abutting the stopper.