US 12,454,965 B2
Landfill pump having metered cycling
Michael K. Lindquist, Plymouth, MI (US); Hunter C. Anstadt, Ann Arbor, MI (US); Mark T. Weinberger, Mounds View, MN (US); and William C. Allen, III, Ypsilanti, MI (US)
Assigned to Graco Minnesota Inc., Minneapolis, MN (US)
Filed by Q.E.D. Environmental Systems, Inc., Dexter, MI (US)
Filed on Nov. 26, 2024, as Appl. No. 18/960,854.
Application 18/960,854 is a continuation of application No. PCT/US2024/023589, filed on Apr. 8, 2024.
Claims priority of provisional application 63/458,187, filed on Apr. 10, 2023.
Prior Publication US 2025/0092884 A1, Mar. 20, 2025
Int. Cl. F04F 1/08 (2006.01); E21B 43/12 (2006.01); F04B 47/04 (2006.01); F04B 53/10 (2006.01); B09B 1/00 (2006.01); F16K 31/20 (2006.01)
CPC F04F 1/08 (2013.01) [E21B 43/121 (2013.01); E21B 43/129 (2013.01); F04B 47/04 (2013.01); B09B 1/006 (2013.01); F16K 31/20 (2013.01)] 17 Claims
OG exemplary drawing
 
17. A landfill pump for pumping a liquid out of a wellbore in a landfill, the landfill pump comprising:
a case, the case being cylindrical and elongated along a pump axis;
a pump chamber located at least partially within the case;
a manifold disposed at a top end of the case;
a liquid inlet, the liquid inlet configured to permit the liquid to flow from outside of the landfill pump within the wellbore and into the pump chamber;
a liquid inlet valve that opens to allow the liquid to flow from the liquid inlet into the pump chamber and closes to block the liquid in the pump chamber from flowing back out of the liquid inlet;
a liquid outlet channel at least partially formed through the manifold and through which the liquid is discharged;
a liquid outlet valve that opens to allow the liquid to flow out of the pump chamber through the liquid outlet channel and closes to block the liquid from flowing through the liquid outlet channel and back into the pump chamber;
a discharge pipe that extends axially within the casing and within the pump chamber, the liquid outlet channel extending at least partially within the discharge pipe;
a valve assembly configured to regulate flow of a compressed gas into the pump chamber to force the liquid within the pump chamber out through the liquid outlet channel, the valve assembly including a pneumatic inlet valve that blocks a pneumatic inlet channel during filling of the liquid into the pump chamber and that is moved to unblock the pneumatic inlet channel during admission of the compressed gas to the pump chamber;
a float that rises and falls within the pump chamber in response to changing levels of the liquid within the pump chamber, such movement of the float actuating the valve assembly between a fill state and a discharge state, the valve assembly admitting the compressed gas into the pump chamber in the discharge state and the valve assembly blocking the admission of the compressed gas into the pump chamber in the fill state;
a control rod interfacing with the float, wherein the float is configured to rise within the pump chamber with a rising liquid level to cause the control rod to actuate the valve assembly to the discharge state, and the float is configured to fall within the pump chamber with a falling liquid level to cause the control rod to actuate the valve assembly to the fill state; and
wherein a pneumatic outlet channel is configured to vent the compressed gas from the pump chamber, wherein a choke is fluidly connected with the pneumatic outlet channel;
wherein the landfill pump is configured to undergo a plurality of pump cycles, each pump cycle comprising a filling phase in which the liquid flows through the liquid inlet into the pump chamber and an evacuation phase in which the valve assembly causes release of the compressed gas into the pump chamber to force the liquid out through the liquid outlet channel;
wherein the choke is formed in a bleed piece connected to the manifold;
wherein the bleed piece includes an inner end oriented towards the pump chamber, an outer end oriented away from the pump chamber, and a fitting passage extending through the inner end and the outer end;
wherein the choke is formed as a portion of the fitting passage, and the fitting passage is wider than the choke upstream of the choke between the choke and the inner end.