Eductor with backflow deflector
View Patent ↗Air gap eductor with backflow deflector deflects backflowing liquid, preventing backflowing liquid from contaminating water supply by contacting water jet nozzle above air gap. Backflow deflector plate blocks 40-80% of rim area at opening at upper end of eductor discharge tube, leaving 60-20% of rim area unblocked. With bifurcated asymmetry of from 40% to 100%, blocked and unblocked rim areas deflect backflowing liquid laterally, away from water jet nozzle.
1. An air gap eductor comprising:
(A) an upper assembly including
(i) a receptacle for receiving a water supply,
(ii) a water jet nozzle,
(B) a lower assembly including
(iii) a discharge tube having an upper end, a lower end, and an inside surface surrounding a passageway through the discharge tube, the upper end of the discharge tube having a transverse opening comprising an unobstructed water jet receiving portion and a rim portion, the rim portion being between the water jet receiving portion and the inside surface of the discharge tube, the water jet receiving portion being aligned to receive a jet of water from the water jet nozzle of the upper assembly;
(iv) a venturi structure inside the discharge tube, the venturi structure being between the upper end of the discharge tube and the lower end of the discharge tube,
(v) a liquid entrainment side passageway into the venturi structure,
(vi) a backflow deflector between an air gap and an inlet into the venturi structure;
(C) connecting structure connecting the upper assembly to the lower assembly, the connecting structure providing the air gap between the water jet nozzle of the upper assembly and the backflow deflector of the lower assembly; and
wherein the backflow deflector comprises a transverse backflow deflector plate, the deflector plate blocking a first part of the rim portion of the opening at the upper end of the discharge tube while leaving unblocked both the water jet receiving portion of the opening as well as a second rim part of the opening at the upper end of the discharge tube, the blocked first part of the rim being from 40 to 80 percent of the rim area and the unblocked second part of the rim being from 20 to 60 percent of the rim area, with the blocked first part of the rim and the unblocked second part of the rim providing a bifurcated asymmetry of from 40% to 100%.
2. The air gap eductor according to claim 1 , wherein the blocked first part of the rim is from 45 to 75 percent of the rim area and the unblocked second part of the rim is from 25 to 55 percent of the rim area, with the blocked first part of the rim and the unblocked second part of the rim providing a bifurcated asymmetry of from 50% to 100%.
3. The air gap eductor according to claim 1 , wherein the blocked first part of the rim is from 50 to 75 percent of the rim area and the unblocked second part of the rim is from 25 to 50 percent of the rim area, with the blocked first part of the rim and the unblocked second part of the rim providing a bifurcated asymmetry of from 50% to 100%.
4. The air gap eductor according to claim 1 , wherein the blocked first part of the rim is from 50 to 60 percent of the rim area and the unblocked second part of the rim is from 40 to 50 percent of the rim area, with the blocked first part of the rim and the unblocked second part of the rim providing a bifurcated asymmetry of from 80% to 100%.
5. The eductor according to claim 1 , wherein the backflow deflector is made from a thermoplastic composition and is nonporous.
6. The eductor according to claim 1 , wherein the water jet receiving portion of the opening at the upper end of the discharge tube is centrally positioned relative to the discharge tube passageway.
7. The eductor according to claim 1 , wherein the backflow deflector has a lower surface which is substantially perpendicular to an axis of the discharge tube.
8. The eductor according to claim 1 , wherein the backflow deflector has an integral collar and press fits around an outside surface of the discharge tube.
9. The eductor according to claim 1 , wherein the backflow deflector has an integral collar and press fits into the inside surface of the discharge tube.
10. The eductor according to claim 1 , wherein the backflow deflector has a plurality of integral legs that extend into the inside of the discharge tube.
11. The eductor according to claim 1 , wherein the water jet nozzle has a circular orifice for emitting a jet of water having a circular cross-section, the discharge tube has a circular cross section, the water jet receiving portion of the opening at the upper end of the discharge tube is circular, the backflow deflector has an integral circular collar that press fits into the inside surface of the discharge tube, and the backflow deflector has a plurality of integral legs that extend into the inside of the discharge tube.
12. The eductor according to claim 11 , wherein the circular orifice on the water jet nozzle has a diameter of from 1.5 to 2.5 millimeters, and the water jet receiving portion has a diameter of from 4 to 6 millimeters and the air gap is from 20 to 35 millimeters.
13. The eductor according to claim 12 , wherein the air gap is from 25 to 30 millimeters and the blocked portion of the rim is 50 percent of the rim area and the unblocked second portion of the rim is 50 percent of the rim area, with the blocked first portion of the rim and the unblocked second portion of the rim providing a bifurcated asymmetry of 100%.
14. The eductor according to claim 11 , wherein the plurality of legs consists of four legs, with three of the legs having lower ends connected by an integral connector, the connector positioned on an opposite side of the backflow deflector from the deflector plate.
15. The eductor according to claim 14 , wherein the connector is arcuate and is secured to an inside surface of each of the three legs, and the circular orifice on the water jet nozzle has a diameter of from 1.5 to 2.5 millimeters, the water jet receiving portion has a diameter of from 4 to 6 millimeters, the air gap is from 25 to 30 millimeters, and the blocked portion of the rim is 50 percent of the rim area and the unblocked second portion of the rim is 50 percent of the rim area, with the blocked first portion of the rim and the unblocked second portion of the rim providing a bifurcated asymmetry of 100%.
16. The eductor according to claim 1 , wherein the backflow deflector is the only deflector between the venturi structure and the air gap.
17. The eductor according to claim 1 , wherein the backflow deflector has a backflow deflector surface that is upwardly sloping away from an inside surface of the discharge tube.
18. The eductor according to claim 1 , further comprising a bypass channel for flow bypassing the venturi structure, with an inner wall of the bypass channel comprising a plurality of spaced grooves extending substantially parallel to the axis of the discharge tube.
19. The eductor according to claim 1 , wherein the lower assembly further comprises a flow restrictor comprising a flow restrictor plug removably received in a socket in the lower assembly, the flow restrictor plug having a plurality of grooves with each groove having a different cross sectional size, with the plug positioned so that a selected groove of the plurality of grooves is positioned to provide a flow rate corresponding with the cross sectional size of the groove.