Eductor apparatus
View Patent ↗An eductor assembly includes an inlet connectable to a high pressure water source useful in firefighting, an outlet connectable to a fire hose and/or nozzle, and a venturi therebetween. An additive inlet communicates with the venturi so that a chemical additive, such as a foam concentrate, is educed into the output stream. A check valve is positioned at the additive inlet to open under venturi flow conditions and remain closed otherwise. An actuator is provided that holds the check valve in its open position while water flows through the eductor assembly under non-venturi conditions to produce a back flow through the additive inlet and ultimately through the additive fluid circuit, including the additive metering valve components. A return element may be disposed within the eductor body to return the check valve to its closed position when the back flow ceases.
1. An eductor assembly for use with firefighting equipment comprising:
an eductor body defining a fluid inlet connectable to a source of a firefighting fluid, a fluid outlet for dispensing fluid therefrom in fluid communication with said fluid inlet, an additive inlet connectable to a source of an additive to the firefighting fluid and in fluid communication with said fluid outlet;
a check valve disposed between said additive inlet and said fluid outlet and moveable, in response to a flow of firefighting fluid through said fluid inlet, between a first position operable to prevent back flow of firefighting fluid through said additive inlet and a second position to permit flow of additive through said additive inlet to said fluid outlet;
an actuator operable from outside said eductor body to move said check valve to said second position, said actuator including;
an elongated pin having a proximal end manually accessible outside said eductor body and an opposite working end engageable with said check valve to move said check valve to said second position; and
said actuator includes means for biasing said pin away from engagement with said check valve.
2. The eductor assembly of claim 1 , wherein said fluid inlet and said fluid outlet are arranged to form a venturi to educe fluid through said additive inlet by suction.
3. The eductor assembly of claim 2 , wherein said check valve is moveable to said second position in response to the suction generated by said venturi.
4. An eductor assembly, for use with firefighting equipment comprising:
an eductor body defining a fluid inlet connectable to a source of a firefighting fluid, a fluid outlet for dispensing fluid therefrom in fluid communication with said fluid inlet, an additive inlet connectable to a source of an additive to the firefighting fluid and in fluid communication with said fluid outlet;
a check valve disposed between said additive inlet and said fluid outlet and moveable, in response to a flow of firefighting fluid through said fluid inlet, between a first position operable to prevent back flow of firefighting fluid through said additive inlet and a second position to permit flow of additive through said additive inlet to said fluid outlet;
an actuator operable from outside said eductor body to move said check valve to said second position; and
a metering head in fluid communication with said additive inlet, said metering head including a metering inlet connectable to the source of an additive and an adjustable metering element disposed between said metering inlet and said additive inlet, wherein said actuator is supported by said metering head to engage said check valve to move said check valve to said second position.
5. The eductor assembly of claim 4 , wherein said actuator is an elongated pin slidably disposed within said metering head and having a proximal end manually accessible outside said metering head and an opposite working end engageable with said check valve to move said check valve to said second position.
6. The eductor assembly of claim 5 , wherein said actuator includes a push button mounted to said proximal end of said pin.
7. The eductor assembly of claim 6 , wherein said metering element is connected to a proportioning knob movably mounted to said metering head, said knob defining a recess for receiving said push button and a bore communicating with said recess slidably receiving said pin therethrough.
8. The eductor assembly of claim 7 , further comprising a mating assembly between said metering head and said additive inlet of said eductor body for removably coupling said metering head thereto.
9. The eductor assembly of claim 7 , wherein said actuator includes a spring between said push button and said proportioning knob within said recess, said spring arranged to bias said pin away from engagement with said check valve.
10. The eductor assembly of claim 5 , wherein said pin extends through said metering element.
11. The eductor assembly of claim 10 , wherein said metering element includes:
a hollow proportioning ball defining a plurality of differently sized metering openings arranged to be selectively aligned with said metering inlet; and
a hollow stem coupled to said proportioning ball and defining a passageway with said pin slidingly disposed therethrough.
12. The eductor assembly of claim 11 , wherein said actuator includes a fluid sealing element disposed between said pin and said hollow stem.
13. The eductor assembly of claim 1 , wherein said check valve includes:
a valve disc sized to close said additive inlet in said first position; and
a number of alignment wings projecting from said valve disc into said additive inlet when said check valve is in either of said first and second positions.
14. The eductor assembly of claim 13 , wherein said number of wings defines a hub arranged to be engaged by said actuator when said actuator is operated to move said check valve to said second position.
15. An eductor assembly, for use with firefighting equipment comprising:
an eductor body defining a fluid inlet connectable to a source of a firefighting fluid, a fluid outlet for dispensing fluid therefrom in fluid communication with said fluid inlet, an additive inlet connectable to a source of an additive to the firefighting fluid and in fluid communication with said fluid outlet;
a check valve disposed between said additive inlet and said fluid outlet and moveable, in response to a flow of firefighting fluid through said fluid inlet, between a first position operable to prevent back flow of firefighting fluid through said additive inlet and a second position to permit flow of additive through said additive inlet to said fluid outlet;
an actuator operable from outside said eductor body to move said check valve to said second position; and
a return element disposed within said eductor body to contact said check valve in opposition to said actuator, said return element being configured to deform when said check valve is moved to said second position by said actuator, wherein said return element includes a ring disposed between said check valve and said eductor body.
16. The eductor assembly of claim 15 , wherein said actuator is an elongated pin having a proximal end manually accessible outside said eductor body and an opposite working end engageable with said check valve to move said check valve to said second position.
17. The eductor assembly of claim 16 , wherein said actuator includes a push button mounted to said proximal end of said pin.
18. The eductor assembly of claim 15 , wherein said ring has an un-deformed shape of an oval.
19. The eductor assembly of claim 15 , wherein:
said return element includes an elongated stem; and
said check valve defines a bore for receiving said elongated stem therethrough.
20. The eductor assembly of claim 19 , wherein said actuator defines a bore for receiving a portion of said elongated stem therethrough.
21. A combination for use with firefighting equipment comprising:
a hose for connecting to source of firefighting fluid;
a source of additive to be combined with the firefighting fluid;
an eductor body defining a fluid inlet connected to the hose, a fluid outlet for dispensing fluid therefrom in fluid communication with said fluid inlet, an additive inlet connected to the source of additive and in fluid communication with said fluid outlet;
a check valve disposed between said additive inlet and said fluid outlet and moveable, in response to a flow of firefighting fluid through said fluid inlet, between a first position operable to prevent back flow of firefighting fluid through said additive inlet and a second position to permit flow of additive through said additive inlet to said fluid outlet;
an actuator operable from outside said eductor body to move said check valve to said second position; and
a metering head in fluid communication with said additive inlet, said metering head including a metering inlet connectable to the source of an additive and an adjustable metering element disposed between said metering inlet and said additive inlet, wherein said actuator is supported by said metering head to engage said check valve to move said check valve to said second position.
22. The combination of claim 21 , wherein said actuator is an elongated pin having a proximal end manually accessible outside said eductor body and an opposite working end engageable with said check valve to move said check valve to said second position.
23. The combination of claim 22 , wherein said actuator includes means for biasing said pin away from engagement with said check valve.
24. The combination of claim 21 , further comprising a mating assembly between said metering head and said additive inlet of said eductor body for removably coupling said metering head thereto.
25. The combination of claim 21 , wherein said check valve includes:
a valve disc sized to close said additive inlet in said first position; and
a number of alignment wings projecting from said valve disc into said additive inlet when said check valve is in either of said first and second positions.
26. The combination of claim 21 , further comprising a return element disposed within said eductor body to contact said check valve in opposition to said actuator, said return element being configured to deform when said check valve is moved to said second position by said actuator.
27. The combination of claim 26 , wherein said return element includes a ring disposed between said check valve and said eductor body.
28. The eductor assembly of claim 1 , further comprising a fluid seal disposed between said actuator and said eductor body.
29. The eductor assembly of claim 4 , further comprising a fluid seal disposed between said actuator and said eductor body.
30. The eductor assembly of claim 15 , further comprising a fluid seal disposed between said actuator and said eductor body.
31. The combination of claim 21 , further comprising a fluid seal disposed between said actuator and said eductor body.