Landfill pump with metered circulation

Abstract

The landfill well pump is pneumatically powered to pump landfill liquid from the landfill well. The landfill well pump includes a throttle port on a pneumatic exhaust of the pump. The throttle port regulates the flow of drive gas out of the landfill pump to maintain pneumatic pressure in the pump and meter the inflow of landfill liquid into the pump.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Application No. 63 / 458,187, filed April 10, 2023, entitled “Landfill Pump Having Metered Cycling,” the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0002] This disclosure relates to landfill pumps. More specifically, this disclosure relates to pneumatically powered landfill pumps that are partially or completely submerged in liquid within a landfill wellbore.

[0003] Landfill pumps are installed in landfill wells located around the landfill site. The pumps are configured to pump landfill liquids from the wells. Due to the contaminating nature of landfill liquids, their collection and proper disposal can be expensive. The supply and discharge of compressed gas (providing compressed gas to the landfill pump for pumping) are regulated to control the outflow from the pump. This regulation is typically achieved using a needle valve located on the pneumatic line above ground, so that the operator can access the valve. This valve requires frequent adjustments to maintain the desired flow rate (e.g., due to changing environmental conditions such as humidity levels, landfill liquid levels, temperature, etc.), which can be expensive and time-consuming. Summary of the Invention

[0004] According to one aspect of this disclosure, a landfill pump for pumping liquid out of a wellbore in a landfill includes a housing, a pump chamber, a liquid inlet, a liquid outlet passage, a valve assembly, and a pneumatic outlet passage, the pump chamber being at least partially located within the housing; the liquid inlet is configured to allow liquid to flow from the outside of the landfill pump into the pump chamber; the liquid is discharged through the liquid outlet passage; the valve assembly is configured to regulate a gas flow entering the pump chamber to force liquid within the pump chamber to be discharged through the liquid outlet; the pneumatic outlet passage is configured to discharge pneumatic gas from the chamber, wherein a throttle orifice is positioned along the pneumatic outlet passage to slow the circulation of the landfill pump by slowing the outflow of gas from the pump chamber and thus slowing the inflow of liquid into the pump chamber.

[0005] According to an additional or alternative aspect of this disclosure, a landfill pump for pumping liquid out of a wellbore in a landfill includes a housing, a pump chamber, a manifold, a liquid inlet, a liquid outlet passage, a valve assembly, and a pneumatic outlet passage, wherein the pump chamber is at least partially located within the housing; the manifold is disposed at the top of the housing; the liquid inlet is configured to allow liquid to flow from the outside of the landfill pump within the wellbore into the pump chamber; the liquid outlet passage is formed at least partially through the manifold, and liquid is discharged through the liquid outlet passage; the valve assembly is configured to regulate the flow of compressed gas entering the pump chamber to force liquid in the pump chamber to flow out through the liquid outlet; the pneumatic outlet passage is configured to discharge pneumatic gas from the pump chamber, wherein a throttle orifice is positioned along the pneumatic outlet passage to slow the circulation of the landfill pump by slowing the discharge of gas from the pump chamber and thus slowing the entry of liquid into the pump chamber. The throttle orifice is formed in a bleed piece connected to the manifold.

[0006] According to another additional or alternative aspect of this disclosure, a landfill pump for pumping liquid out of a wellbore in a landfill includes a housing, a pump chamber, a manifold, a liquid inlet, a liquid outlet passage, a valve assembly, and a pneumatic outlet passage, the pump chamber being at least partially located within the housing; the manifold being disposed at the top of the housing; the liquid inlet being configured to allow liquid to flow from the outside of the landfill pump within the wellbore into the pump chamber; the liquid being discharged through the liquid outlet passage; the valve assembly being configured to regulate the flow of compressed gas into the pump chamber to force liquid within the pump chamber to flow out through the liquid outlet; the pneumatic outlet passage being formed at least partially through the manifold and configured to discharge pneumatic gas from the pump chamber, wherein a throttle orifice is positioned along the pneumatic outlet passage to slow the circulation of the pump by slowing the discharge of gas from the pump chamber and thus slowing the entry of liquid into the pump chamber, the throttle orifice being formed as an orifice through a structure of the manifold.

[0007] According to yet another additional or alternative aspect of this disclosure, a landfill pump for pumping liquid out of a wellbore in a landfill includes a housing, a pump chamber, a liquid inlet, a liquid outlet passage, a valve assembly, a pneumatic inlet passage, a pneumatic outlet passage, a float, a discharge pipe, and a control rod, wherein the pump chamber is at least partially located within the housing; the liquid inlet is configured to allow liquid to flow into the pump chamber from the outside of the landfill pump within the wellbore; the liquid is discharged through the liquid outlet passage; the valve assembly is configured to regulate the flow of compressed gas into the pump chamber to force liquid within the chamber to flow out through the liquid outlet; the pneumatic inlet passage is configured to supply compressed gas to the pump chamber; the pneumatic... An outlet passage is configured to discharge compressed gas from a pump chamber; the float is configured to axially displace along a pump axis to actuate the valve assembly between a filled state and a discharged state, wherein in the filled state, the pneumatic inlet passage is fluidly disconnected from the pump chamber, and in the discharged state, the pneumatic inlet passage is fluidly connected to the pump chamber; a discharge pipe has at least one port formed through the discharge pipe, the discharge pipe being configured to deliver liquid to the liquid outlet; a control rod abuts the float, the control rod including an upper stop defining an upward travel limit of the float along the control rod and a lower stop defining a downward travel limit of the float along the control rod. The float is configured to enable the control rod to actuate the valve assembly to a discharged state via the upper stop, and the float is configured to enable the control rod to actuate the valve assembly to a filled state via the lower stop. The pump chamber includes a venting chamber axially disposed between a lower stop and at least one port, the venting chamber having a first axial length, and the pump chamber having a second axial length between the at least one port and a liquid outlet. When the float is at its downward stroke limit and the valve assembly is in a filled state, the first axial length is at least one-quarter of the second axial length, to provide a volumetric space between the float and at least one port for allowing compressed gas to enter the pump chamber when the valve assembly is in a vented state, to expand the valve assembly after actuation to the filled state, and to continue driving liquid out of the pump chamber.

[0008] According to another additional or alternative aspect of this disclosure, a method of circulating a landfill pump configured to pump liquid from a wellbore in a landfill includes: allowing a flow of compressed gas from a pneumatic inlet passage of the landfill pump into a pump chamber while the valve assembly of the landfill pump is in a venting state, the compressed gas driving liquid to flow downward within the pump chamber, then upward along a distribution pipe, and out through a liquid outlet of the landfill pump; actuating the valve assembly to a filling state, in which the flow of compressed gas into the pump chamber is cut off; and restricting the outflow of compressed gas from the pump chamber through a throttle orifice provided in the pneumatic outlet passage of the landfill pump to slow down the circulation of the landfill pump by slowing the outflow of compressed gas from the pump chamber and thus slowing the inflow of liquid into the pump chamber.

[0009] According to another additional or alternative aspect of this disclosure, a method of circulating a landfill pump configured to pump liquid from a wellbore in a landfill includes: raising a float in the pump chamber of the landfill pump to a maximum stroke limit to actuate a valve assembly to a discharge state via a control lever; allowing a flow of compressed gas from a pneumatic inlet passage of the landfill pump into the pump chamber while the valve assembly is in the discharge state, the compressed gas driving the liquid in the pump chamber downward and into a distribution pipe through at least one port, then upward along the distribution pipe and out through the liquid outlet of the landfill pump; and using a lower stop at the lower stroke limit of the float along the... A control lever stops the downward stroke of the float, which in turn actuates the control lever to actuate the control valve assembly to a filled state, in which the flow of compressed gas to the pump chamber is cut off. A lower stop stops the downward stroke of the float, forming an expansion chamber within the pump chamber with a first axial length between the lower limit of the stroke and at least one port. The outflow of compressed gas from the pump chamber is restricted by a throttling orifice disposed within the pneumatic outlet passage of the landfill pump, allowing the compressed gas within the pump chamber to continue expanding while the valve assembly is in the filled state, thus enabling the landfill pump to continue discharging liquid while the valve assembly is in the filled state. The first axial length is at least 20% of a second axial length of the pump chamber between the at least one port and the upper end of the pump chamber. Attached Figure Description

[0010] Figure 1 This is an isometric view of a landfill pump.

[0011] Figure 2 This is an isometric view of a landfill pump, with the outer casing removed to expose the internal components of the landfill pump.

[0012] Figure 3A It is along Figure 1 The sectional view taken by line 3-3 in the figure.

[0013] Figure 3B yes Figure 3A A magnified view of detail B in the image.

[0014] Figure 4 It is along Figure 1 The sectional view taken by line 4-4 in the figure.

[0015] Figure 5 Is with Figure 3B The view shown is a cross-sectional view of a manifold.

[0016] Figure 6 This is a cross-sectional view of the discharge assembly used for landfill pumps.

[0017] Figure 7 This is a cross-sectional view of the pneumatic fittings used in landfill pumps.

[0018] Figure 8 This is an enlarged isometric view of the landfill pump, showing the venting component disassembled from the landfill pump in sectional view. Detailed Implementation

[0019] This disclosure generally relates to landfill pumps. Landfill pumps are configured to pump liquids from landfill wells. Such liquids can be any type of liquid accumulated in a landfill well. Typically, such liquids are aqueous leachate and / or other contaminants containing debris and / or substances that may be highly corrosive to pump components. The environment within landfill wells can be particularly hot due to the ongoing decomposition reactions of the landfill contents. Therefore, landfill pumps must be made of particularly robust materials and have a design that minimizes wear, adhesion, and failure points.

[0020] The landfill pump is configured to regulate the discharge of driving gas from within the pump. The pump includes a throttling orifice forming a vent passage through which the exhaust gas exits the pump. This throttling orifice is a constriction that slows the flow of the exhaust gas, thereby reducing the discharge of gas from the pump and consequently slowing the entry of landfill liquid into the pump. The throttling orifice is positioned along a pneumatic outlet passage through which the exhaust gas flows to exit the pump chamber.

[0021] Landfill pumps can be float-actuated to allow circulation by the pump. The float can actuate a valve to open, allowing compressed gas to flow into the pump, thereby pumping landfill liquid from the pump. The float's stroke is both upward and downward within the pump. The float can also actuate to close the valve to stop the flow of compressed gas into the pump. The downward stroke of the float during compressed gas inflow is restricted, causing an expansion chamber to form within the pump when the valve closes to stop the inflow of compressed gas. The restriction of the float's stroke actuates the valve to the closed position more quickly, allowing the compressed gas that has been allowed into the pump chamber to continue expanding within the expansion chamber, continuing to expel liquid from the pump chamber. The expansion chamber between the float and the discharge port allows the incoming drive gas to expand while preventing drive gas from flowing into the discharge pipe and upward into the discharge line that delivers landfill liquid from the pump.

[0022] When components are arranged at a common axial position along an axis, the components can be considered radially overlapping. A radial line extending from the axis will extend through each of the radially overlapping components. When those components are arranged relative to the axis at a common radial and circumferential position such that an axis parallel to said axis extends through the axially overlapping components, the components can be considered axially overlapping. When aligned about an axis, the components can be considered circumferentially overlapping such that a circle centered on the axis passes through the circumferentially overlapping components.

[0023] Figure 1 This is an isometric view of the landfill pump 10. Figure 2 This is an isometric view of the landfill pump 10, in which the housing 12 is removed to expose the internal components of the landfill pump 10. Figure 1 and Figure 2 Let's discuss this together. The diagram shows the housing 12, manifold 14, liquid inlet 16, liquid outlet 18, pneumatic inlet 20, pneumatic outlet 22, discharge pipe 24, float 26, control lever 28, liquid inlet valve 30, valve assembly 32, and filter 34 of the landfill pump 10. The discharge pipe 24 includes a port 36.

[0024] Landfill pump 10 is typically lowered into the wellbore of the landfill via a cable assembly. The cable assembly may include a hose for supplying pressurized gas from the surface. The cable assembly may also include a discharge hose that carries the discharge liquid upward from landfill pump 10 to the surface for discharge into a container. Due to the narrow space inside the wellbore, the connection point for the cable assembly is located at the top of landfill pump 10, while the liquid inlet 16 is located at the bottom of landfill pump 10.

[0025] The landfill pump 10 is configured to operate in a series pump cycle. Each pump cycle includes a filling phase and a venting phase. During the filling phase, fluid from the landfill wellbore can flow into the interior of the landfill pump 10 to fill the landfill pump 10 with landfill fluid. During the venting phase, compressed gas is allowed to enter the interior of the landfill pump 10 to expel the fluid from the landfill pump 10. After the venting phase is completed, the landfill pump 10 returns to the filling phase.

[0026] The housing 12 defines an internal pump chamber 38 within the landfill pump 10. Figure 3A and Figure 4 (The best is shown in the image). The housing 12 forms the exterior of the landfill pump 10. The housing 12 may be completely or partially submerged in the landfill liquid, wherein the landfill pump 10 is disposed within the landfill wellbore. The housing 12 may be a cylindrical tube made of metal, polymer, epoxy resin composite and / or other materials.

[0027] Liquid inlet 16 is located at the lower end of landfill pump 10. Filter 34 is located at liquid inlet 16. Filter 34 is an external filter. For example, filter 34 may be in the form of a screen, which filters out large debris from the liquid, thereby preventing debris from entering landfill pump 10. Landfill pump 10 is at least partially submerged in the liquid within the landfill wellbore, such that liquid inlet 16 is below the surface of the liquid and can easily draw surrounding liquid into landfill pump 10.

[0028] Liquid outlet 18 is located at the end of landfill pump 10 opposite to liquid inlet 16. In the example shown, liquid outlet 18 is located at the top of landfill pump 10. Liquid outlet 18 can be connected to a discharge hose that guides the liquid discharged from landfill pump 10 upwards to the ground.

[0029] At the top of the landfill pump 10 is a pneumatic inlet 20. The pneumatic inlet 20 may include a fitting for attaching to a hose that supplies gas to the landfill pump 10 under pressure. This pneumatic supply hose may extend to the ground where the pressurized gas supply is located. At the top of the landfill pump 10 is a pneumatic outlet 22. The pneumatic outlet 22 may connect to a fitting of a pneumatic discharge hose that extends to the ground to capture exhaust gases. Alternatively, the pneumatic outlet 22 may discharge gas directly into the wellbore without a hose.

[0030] Manifold 14 is disposed at the top of landfill pump 10. In the example shown, housing 12 extends around a portion of manifold 14 and is sealed using manifold 14. In the example shown, manifold 14 abuts against the top of housing 12. Liquid outlet 18, pneumatic inlet 20, and pneumatic outlet 22 of landfill pump 10 may be formed as part of manifold 14 or otherwise extend from or be supported by manifold 14, but it should be understood that other configurations are also possible. Manifold 14 may be made of metal (and other options). For example, manifold 14 may be formed of stainless steel.

[0031] Discharge line 24 is fluidly connected to liquid outlet 18 to supply landfill liquid to liquid outlet 18. In the example shown, discharge line 24 abuts against and extends from manifold 14. For example, discharge line 24 may be directly connected to manifold 14, such as via engaging threads, press-fit connections, bayonet connections, and other options. In some examples, discharge line 24 may extend through and over manifold 14 to form liquid outlet 18. Discharge line 24 extends from the bottom end of landfill pump 10 to the top end of landfill pump 10. Discharge line 24 may extend between liquid inlet valve 30 and manifold 14.

[0032] Port 36 is formed through discharge pipe 24. It should be understood that discharge pipe 24 may include one or more ports 36. Port 36 provides a passage for landfill liquid to flow from pump chamber 38 within housing 12 into discharge pipe 24. Port 36 is located at the bottom end of discharge pipe 24. Port 36 is located at the end of discharge pipe 24 opposite to manifold 14. Port 36 extends radially along the pump axis PA relative to the discharge pipe 24.

[0033] Valve assembly 32 can be actuated between a filling state associated with the filling phase of landfill pump 10 and a dispensing state associated with the venting phase of landfill pump 10. In some examples, valve assembly 32 is configured as a rocker valve that switches between a first state and a second state. In the filling state, pneumatic inlet 20 is fluidly disconnected from the interior of landfill pump 10, and pneumatic outlet 22 is fluidly connected to the interior of landfill pump 10, allowing compressed gas to be discharged through pneumatic outlet 22. In the venting state, pneumatic inlet 20 is fluidly connected to the interior of landfill pump 10, allowing compressed gas to enter landfill pump 10 to drive liquid downwards within landfill pump 10, then upwards along discharge pipe 24 and out through liquid outlet 18. In some examples, when valve assembly 32 is in the venting state, pneumatic outlet 22 is fluidly disconnected from the interior of landfill pump 10; however, it should be understood that not all examples are limited to this.

[0034] Float 26 is disposed at least partially around discharge pipe 24. While the examples shown include float 26, it should be understood that not all examples are limited to this. Float 26 may be made of a material with a density less than that of the landfill liquid, such that float 26 is buoyant when partially submerged in the liquid filling pump chamber 38. Float 26 is configured to actuate valve assembly 32 to a discharge state to allow compressed gas to enter pump chamber 38 through pneumatic inlet 20. Float 26 may be configured to actuate valve assembly 32 to a fill state, in which the flow of compressed gas into landfill pump 10 is cut off. Float 26 may drive valve assembly 32 to control the inflow and / or outflow of compressed gas from landfill pump 10. For example, float 26 rising as the liquid level rises and reaches its upward stroke limit may actuate valve assembly 32 to a discharge state, and float 26 falling as the liquid level falls and reaches a lower formation limit or downward stroke limit may actuate valve assembly 32 to a fill state.

[0035] Control lever 28 engages with float 26. In some examples, control lever 28 may extend through float 26. Float 26 is configured to travel axially relative to axis PA as the liquid level changes within landfill pump 10. Control lever 28 and drain pipe 24 may guide float 26 within landfill pump 10 and limit axial movement of float 26. Control lever 28 defines a downward stroke end of float 26. Control lever 28 may define an upward stroke end of float 26.

[0036] In the filling state, the pneumatic inlet valve for the compressed air flow from pneumatic inlet 20 into the interior of the landfill pump 10 is closed. Upward movement of the control lever 28 switches valve assembly 32 to the venting state, in which pneumatic inlet 20 is fluidly connected to the interior of the landfill pump 10, thereby transitioning the landfill pump 10 to the venting stage, in which pressurized gas is released from manifold 14 into the interior of the landfill pump 10. This release of pressurized gas pushes the liquid within the landfill pump 10 downward to close the liquid inlet valve 30 and forces the liquid within the landfill pump 10 into one or more ports 36 at the lower end of the discharge pipe 24, and upward along the discharge pipe 24 and out of the liquid outlet 18. The venting of the liquid causes a decrease in the liquid level within the landfill pump 10, which correspondingly causes the float 26 to move downward. In some examples, when float 26 reaches the end of its downward stroke, float 26 can cause control lever 28 to move downward, thereby switching valve assembly 32 back to the filling state. This disconnects pneumatic inlet 20 from the internal fluid of landfill pump 10 to prevent further release of pressurized gas into landfill pump 10.

[0037] With valve assembly 32 in the filling state, any remaining pressurized gas in the landfill pump 10 can be vented through pneumatic outlet 22. As the pressure inside the landfill pump 10 decreases, the venting phase ends, and the landfill pump 10 transitions to the filling phase when liquid can move through liquid inlet 16, through liquid inlet valve 30, and into the interior of the landfill pump 10 to restart the pump cycle.

[0038] Figure 3A It is along Figure 1 The sectional view taken from line 3-3 in the figure. Figure 3B yes Figure 3A A magnified view of detail B in the image. See also: Figure 1 and Figure 2 Let's discuss Figure 3A and Figure 3B The diagram shows the housing 12, manifold 14, liquid inlet 16, liquid outlet 18, pneumatic inlet 20, pneumatic outlet 22, discharge pipe 24, float 26, liquid inlet valve 30, valve assembly 32, filter 34, pump chamber 38, liquid outlet valve 40, pneumatic inlet valve 42, pneumatic outlet valve 44, pneumatic inlet passage 46, liquid outlet passage 48, pneumatic outlet passage 50, throttle orifice 52, liquid fitting 54, pneumatic fitting 56a, pneumatic fitting 56b, and discharge fitting 58 of the landfill pump 10. The discharge pipe 24 includes a port 36. The liquid inlet valve 30 includes an inlet valve assembly 60 and an inlet valve seat 62. The liquid outlet valve 40 includes an outlet valve assembly 64 and an outlet valve seat 66. The manifold 14 includes pneumatic passages 68a and 68b and a liquid passage 70. The pneumatic passage 68b includes an outlet valve orifice 72, an outlet fitting orifice 74, and a vent barrier 76.

[0039] Compressed gas is directed into pump chamber 38 to transfer landfill liquid, and discharged from landfill pump 10 through discharge pipe 24 and liquid outlet 18. Compressed gas from pump chamber 38 is discharged as exhaust gas. In the example shown, compressed gas is directed into and discharged from pump chamber 38 via manifold 14. Manifold 14 is located at the top of housing 12 and abuts against housing 12. In the example shown, manifold 14 is at least partially disposed within housing 12.

[0040] A liquid inlet valve 30 is located at the bottom of the landfill pump 10. The liquid inlet valve 30 is configured to allow landfill liquid to flow into the pump chamber 38 and prevent landfill liquid from flowing out of the pump chamber 38 through the liquid inlet 16. In the example shown, the liquid inlet valve 30 is configured as a one-way check valve. Liquid pressure in the wellbore drives liquid from inside the wellbore through the liquid inlet valve 30 into the pump chamber 38. A liquid outlet valve 40 is located at the top of the landfill pump 10. In the example shown, the liquid outlet valve 40 is supported by the manifold 14. The liquid outlet valve 40 is configured to allow landfill liquid to leave the landfill pump 10 during the purging phase and is configured to close to prevent the purged landfill liquid from flowing back into the landfill pump 10. In the example shown, the liquid outlet valve 40 is configured as a one-way check valve. During the purging phase, pressure applied by compressed gas to the liquid within the pump chamber 38 drives the liquid upward along the discharge pipe 24 and through the liquid outlet valve 40. The liquid outlet valve 40 returns to a closed state to prevent backflow of liquid.

[0041] A liquid inlet 16 is located at the bottom of the landfill pump 10, and a liquid outlet 18 is located at the top of the landfill pump 10. A liquid outlet passage 48 is formed through the manifold 14. In the example shown, the liquid outlet passage 48 is aligned along axis PA. The liquid outlet passage 48 extends completely through the manifold 14 from its bottom side 78 to its top side 80. The liquid outlet passage 48 can be considered to be at least partially located within the discharge pipe 24 and at least partially located within the liquid fitting 54. A liquid passage 70 is formed by one or more holes extending into the manifold 14. The discharge pipe 24 and the liquid fitting 54 abut against the manifold 14 within the liquid passage 70.

[0042] Discharge line 24 is connected to manifold 14. Discharge line 24 is directly connected to manifold 14 at liquid passage 70. In the example shown, discharge line 24 extends into liquid passage 70 to mate with manifold 14. Discharge line 24 extends into liquid passage 70 through bottom side 78 of manifold 14. It should be understood that in some examples, discharge line 24 may extend axially through manifold 14 completely, such that discharge line 24 protrudes through both top side 80 and bottom side 78 of manifold 14. In this example, discharge line 24 may extend completely through liquid passage 70.

[0043] Liquid fitting 54 is connected to manifold 14. At liquid passage 70, liquid fitting 54 is directly connected to manifold 14. In the example shown, liquid fitting 54 extends into liquid passage 70 to mate with manifold 14. Liquid fitting 54 extends into liquid passage 70 through top side 80 of manifold 14. Liquid fitting 54 is configured to connect to a hose that delivers pumped landfill liquid from landfill pump 10 to the surface. In the example shown, liquid fitting 54 is formed separately from discharge pipe 24; however, it should be understood that not all examples are so limited. For example, in an example where discharge pipe 24 extends axially entirely through manifold 14, liquid fitting 54 may be connected to or formed from discharge pipe 24. In the example shown, liquid outlet valve 40 is disposed within liquid fitting 54.

[0044] A pneumatic inlet passage 46 is at least partially formed in the manifold 14. The pneumatic inlet passage 46 extends through the manifold 14 and opens through the top side 80 and bottom side 78 of the manifold 14. During the purging phase, the pneumatic inlet passage 46 provides a pathway for compressed gas to enter the pump chamber 38. A pneumatic passage 68a is formed by one or more holes within the manifold 14. The pneumatic inlet passage 46 extends through the pneumatic passage 68a to deliver compressed gas from the outside of the landfill pump 10 into the pump chamber 38. An inlet valve seat 62 and a pneumatic mating member 56a are mounted in the pneumatic passage 68a.

[0045] Pneumatic fitting 56a connects to manifold 14. In the example shown, pneumatic fitting 56a connects directly to manifold 14. For example, pneumatic fitting 56a may be threaded onto manifold 14 (among other options). Pneumatic fitting 56a extends through the top side 80 of manifold 14 into manifold 14. Pneumatic fitting 56a is configured to connect to a gas supply hose that delivers compressed gas to landfill pump 10. In the example shown, pneumatic fitting 56a extends into pneumatic passage 68a to connect to manifold 14.

[0046] A pneumatic outlet passage 50 is formed through manifold 14. The pneumatic outlet passage 50 extends through manifold 14 and is opened through the top side 80 and bottom side 78 of manifold 14. During the filling phase, the pneumatic outlet passage 50 provides a flow path for compressed gas to exit from pump chamber 38. A pneumatic passage 68b is formed through manifold 14. Pneumatic passage 68b is formed by one or more orifices within manifold 14. The pneumatic outlet passage 50 extends through pneumatic passage 68b to deliver compressed gas from inside pump chamber 38 to the outside of landfill pump 10. Discharge fitting 58 and pneumatic fitting 56b are mounted in pneumatic passage 68b.

[0047] Pneumatic fitting 56b is connected to manifold 14. In the example shown, pneumatic fitting 56b is directly connected to manifold 14. For example, pneumatic fitting 56b may be threaded onto manifold 14 (and other options) at outlet fitting port 74. Outlet fitting port 74 is part of pneumatic passage 68b and opens through the top side of manifold 14. Pneumatic fitting 56b extends through the top side 80 of manifold 14 into manifold 14. Pneumatic fitting 56b is configured to connect to a gas discharge hose that delivers compressed gas discharged from burial pump 10. In some examples, pneumatic fitting 56b is not connected to a discharge hose, and pneumatic fitting 56b discharges gas into the wellbore. In some examples, burial pump 10 does not include pneumatic fitting 56b associated with pneumatic outlet passage 50, such as in examples where burial pump 10 is configured to discharge gas into the wellbore.

[0048] The discharge fitting 58 connects to the manifold 14. At the pneumatic passage 68 (such as at the outlet valve port 72), the discharge fitting 58 connects to the manifold 14. The outlet valve port 72 opens through the bottom side 78 of the manifold 14. For example, the discharge fitting 58 may connect to the manifold 14 at a threaded interface (among other connection options). In the example shown, the discharge fitting 58 extends at least partially into the manifold 14. The discharge fitting 58 extends into the manifold 14 through the bottom side 78 of the manifold 14. The discharge fitting 58 defines a portion of the pneumatic outlet passage 50 for allowing exhaust gas to exit from the pump chamber 38.

[0049] In the discharge state, valve assembly 32 allows compressed gas to enter the pump chamber 38, and in the filling state, valve assembly 32 prevents compressed gas from entering the pump chamber 38. During the filling of the pump chamber 38 with liquid through liquid inlet 16, pneumatic inlet valve 42 blocks pneumatic inlet passage 46, and during the entry of compressed gas into the pump chamber 38 through pneumatic inlet valve 42 to drive liquid out of the pump chamber 38 through liquid outlet 18, pneumatic inlet valve 42 is moved to prevent blockage of pneumatic inlet passage 46. Valve assembly 32 may include pneumatic outlet valve 44 configured to block pneumatic outlet passage 50 during the entry of compressed gas into the pump chamber 38 through pneumatic inlet valve 42 to drive liquid out of the pump chamber 38 through liquid outlet 18. During the filling of the pump chamber 38 with liquid through liquid inlet 16, pneumatic outlet valve 44 can be moved to prevent blockage of pneumatic outlet passage 50.

[0050] Valve assembly 32 is at least partially disposed within pump chamber 38. In the example shown, assembly base 82 is at least partially disposed around discharge pipe 24. Assembly base 82 may be connected to discharge pipe 24, such as at a pivot point in the example where valve assembly 32 is configured as a rocker assembly. Inlet valve member 60 and outlet valve member 64 extend from assembly base 82 of valve assembly 32. Both inlet valve member 60 and outlet valve member 64, supported by assembly base 82, facilitate simultaneous actuation of pneumatic inlet valve 42 and pneumatic outlet valve 44.

[0051] In the example shown, an interface between the inlet valve member 60 and the inlet valve seat 62 is formed within the manifold 14. The inlet valve seat 62 is disposed within the pneumatic passage 68a. The inlet valve member 60 extends from the assembly base 82 through the bottom side 78 of the manifold 14 into the pneumatic passage 68a. The inlet valve member 60 abuts against the inlet valve seat 62 to close the pneumatic inlet valve 42. The inlet valve member 60 disengages completely or partially from the inlet valve seat 62 to open the pneumatic inlet valve 42 and allow compressed gas to enter the pump chamber 38. The interface between the inlet valve member 60 and the inlet valve seat 62 is disposed within the manifold 14 at a location where it radially overlaps with the manifold 14 along the channel axis ICA of the pneumatic passage 68a.

[0052] In the example shown, the outlet valve seat 66 is formed by the discharge mating part 58. However, it should be understood that not all examples are so limited. For example, the outlet valve seat 66 may be formed from the material of the manifold 14 itself, or from another component mounted to the manifold 14.

[0053] An outlet valve member 64 extends from the assembly base 82. The outlet valve member 64 may be at least partially disposed within the pneumatic outlet passage 50. In the example shown, the outlet valve member 64 extends into the discharge mating member 58. It should be understood that in some examples, the outlet valve member 64 may extend into the manifold 14 to radially overlap with the structure of the manifold 14 relative to the passage axis OCA. The outlet valve member 64 abuts against the outlet valve seat 66 to close the pneumatic outlet valve 44. The outlet valve member 64 disengages completely or partially from the outlet valve seat 66 to open the pneumatic outlet valve 44 and fluidly connect the pneumatic outlet passage 50 to the pump chamber 38, thereby allowing compressed gas to exit from the pump chamber 38.

[0054] The opening and closing of the pneumatic outlet valve 44 fluidly connects and disconnects the pump chamber 38 and the pneumatic outlet passage 50. Gas discharged from the pump chamber 38 travels through the pneumatic outlet valve 44 and the pneumatic outlet passage 50 and is discharged from the packing pump 10. As previously described, this discharge can travel from the pneumatic outlet passage 50 to an upwardly extending hose, such as through the pneumatic fitting 56b, or it can be discharged directly into the wellbore. In various examples, the pneumatic outlet passage 50 extends through the manifold 14 and may extend above and / or below the manifold 14.

[0055] In the example shown, the pneumatic passage 68b is formed by an outlet mating orifice 74, an outlet valve orifice 72, and a throttle orifice 52. The throttle orifice 52 extends between and fluidly connects the outlet mating orifice 74 and the outlet valve orifice 72. At the outlet mating orifice 74, a pneumatic fitting 56b is mounted to the manifold 14 (e.g., via a threaded interface). At the outlet valve orifice 72, a discharge fitting 58 is mounted to the manifold 14 (e.g., via a threaded interface). In the example shown, the throttle orifice 52 is formed and defined by the structure of the manifold 14. A vent barrier 76 is disposed between the outlet mating orifice 74 and the outlet valve orifice 72. In the example shown, the vent barrier 76 narrows the pneumatic passage 68, and the throttle orifice 52 is formed as an orifice through the vent barrier 76. However, it should be understood that not all examples are so restricted. For example, the orifice 52 may be formed in a plug or vent that is separate from the manifold 14, and the orifice 52 may be installed into the manifold 14, as discussed in more detail below.

[0056] A throttle orifice 52 is disposed in and defines a portion of the pneumatic outlet passage 50. The throttle orifice 52 is a narrowing portion of the pneumatic outlet passage 50. The effective diameter of this narrowing portion may be greater than 50% of the pneumatic outlet passage 50. The effective diameter of this narrowing portion may be greater than 75% of the pneumatic outlet passage 50. The effective diameter of this narrowing portion may be greater than 90% of the pneumatic outlet passage 50. In some examples, the pneumatic outlet passage 50 may be configured to have an inner diameter of at least 0.2 inches (in.) (at least 0.508 centimeters (cm)) along most of its length. In some examples, the pneumatic outlet passage 50 may have an inner diameter of at least 0.2 inches (approximately 0.508 cm) along its entire length, except for the portion along the narrower throttle orifice 52.

[0057] The orifice 52 may be located downstream of the pneumatic outlet valve 44, but it should be understood that not all examples are so restricted. In the example shown, the orifice 52 is located within the manifold 14, but in various other examples, the orifice 52 may be mounted on or otherwise attached to the manifold 14. In the example shown, the orifice 52 is formed as an aperture through a structure of the manifold 14.

[0058] The throttle orifice 52 inhibits, but does not stop, the flow of pressurized gas from the pump chamber 38 through the pneumatic outlet passage 50. Thus, the throttle orifice 52 slows the circulation of the landfill pump 10 because liquid enters the pump chamber 38 only when the liquid pressure is nearly equal to the pressure inside the pump chamber 38. If pressurized gas remains in the pump chamber 38 after the purging phase, the residual pressurized gas will subsequently slow the flow of liquid into the pump chamber 38 through the liquid inlet 16, thereby making the filling phase of the pump circulation longer. This has the overall effect of slowing the circulation of the landfill pump 10, which is advantageous for applications requiring low circulation and low flow rates.

[0059] It is more advantageous to block the gas from the venting of the burial pump 10 than to block the inlet of the pressurized gas, because blocking the inlet of the pressurized gas would impair the power of the burial pump 10 during the venting phase of the pump cycle. Unlike the needle valve, the throttle orifice 52 in the illustrated example is a fixed-size passage and is not adjustable. The throttle orifice 52 is located at the burial pump 10 and within the wellbore. Thus, the throttle orifice 52 is not subjected to environmental conditions that would require frequent adjustment of the valve controlling gas discharge. Consequently, the throttle orifice 52 provides a stable outflow and circulation time for the burial pump 10.

[0060] The orifice 52 is configured to provide a stable circulation for the landfill pump 10. This allows the landfill pump 10 to output liquid at a consistent rate, enabling the user to better plan the capture and treatment of the pumped liquid. In some examples, the orifice 52 is configured such that the landfill pump 10 can output liquid at a rate up to approximately 2.5 gallons per minute (GPM). In some examples, the orifice 52 is configured such that the landfill pump 10 can output liquid at a flow rate up to approximately 1.5 GPM. However, it should be understood that the orifice 52 can be sized in any desired manner to provide the desired flow rate.

[0061] The orifice 52 has a length L1 and a diameter D1. The length L1 of the orifice can be less than about 1 inch (about 2.54 cm). In some examples, the length L1 of the orifice 52 is up to about 0.5 inches (about 1.27 cm). In some examples, the length L1 of the orifice 52 is up to about 0.2 inches (about 0.508 cm). The diameter D1 of the orifice 52 is less than the length L1 of the orifice 52 to form a restriction that slows the gas out of the pump chamber 38. In some examples, the diameter D1 of the orifice 52 is up to about 0.2 inches (about 0.508 cm). In some examples, the diameter D1 of the orifice 52 is up to about 0.1 inches (about 0.254 cm). In some examples, the diameter D1 of the orifice 52 is up to about 0.05 inches (about 0.127 cm). In some examples, the diameter D1 of the orifice 52 is up to about 0.04 inches (about 0.1016 cm). It should be understood that the orifice 52 may have a diameter-to-length ratio that is sized to slow the discharge of compressed gas while allowing the filling pump 10 to continue moving forward through the pump cycle. In some examples, the diameter-to-length ratio of the orifice 52 is approximately 1:5 or greater, such that the length L1 is at least five times the diameter D1.

[0062] During operation, the landfill pump 10 operates in a series of pump cycles, alternating between a filling phase and a venting phase in each pump cycle. During the filling phase, fluid from outside the landfill pump 10, or from within the wellbore where the landfill pump 10 is partially or fully submerged, flows through the fluid inlet 16 and through the fluid inlet valve 30 into the internal pump chamber 38. During the filling phase, the fluid inlet valve 30 is open. During the filling phase, the pneumatic inlet valve 42 is closed, and the pneumatic outlet 22 is fluidly connected to the pump chamber 38. The fluid level within the pump chamber 38 rises to partially submerge the float 26, eventually causing the float 26 to begin rising within the pump chamber 38. The rising of the float 26 switches the valve assembly 32, actuating it from a filling state associated with the filling phase to a venting state associated with the venting phase.

[0063] Valve assembly 32 is actuable between a filled state and a vented state. In some examples, valve assembly 32 is configured to include or include a rocker arm mechanism configured to be actuated by float 26. In some examples, valve assembly 32 is configured to translate linearly relative to axis PA between the filled and vented states. Pneumatic inlet valve 42 is closed when valve assembly 32 is in the filled state, and pneumatic outlet valve 44 is open when valve assembly 32 is in the filled state. Pneumatic inlet valve 42 is open when valve assembly 32 is in the vented state, and pneumatic outlet valve 44 is closed when valve assembly 32 is in the vented state.

[0064] During the filling cycle, the pneumatic inlet valve 42 is closed and the pneumatic outlet valve 44 is open. The closed pneumatic inlet valve 42 prevents pressurized gas from flowing into the pump chamber 38. The open pneumatic outlet valve 44 allows compressed gas to exit from the pump chamber 38 and through the pneumatic outlet passage 50. Landfill liquid flows into the pump chamber 38 through the liquid inlet 16 and displaces the float 26 toward the valve assembly 32. The pump chamber 38 is fluidly connected to the pneumatic outlet passage 50, and gas within the pump chamber 38 can flow through the open pneumatic outlet valve 44, through the throttle orifice 52, and out of the landfill pump 10 through the pneumatic outlet passage 50. As discussed above, the throttle orifice 52 regulates the outflow of gas to slow the rate of gas exiting the pump chamber 38, thereby slowing the filling rate of the landfill pump 10. When float 26 reaches the upward end of its stroke, valve assembly 32 is actuated to the discharge state, and pneumatic inlet valve 42 switches to the open state, while pneumatic outlet valve 44 switches to the closed state. The upward movement of float 26 causes valve assembly 32 to switch to the dispensing state with pneumatic inlet valve 42 open.

[0065] Opening the pneumatic inlet valve 42 switches the landfill pump 10 to the venting stage, during which pressurized gas is released from the pneumatic inlet passage 46 into the pump chamber 38. The compressed gas flows through the pneumatic inlet passage 46, through the open pneumatic inlet valve 42, and into the pump chamber 38. The compressed gas causes the liquid within the pump chamber 38 to shift downwards between the housing 12 and the discharge pipe 24, entering the discharge pipe 24 through port 36, then upwards through the discharge pipe 24 and exiting the landfill pump 10 through the liquid outlet passage 48 and the liquid outlet 18.

[0066] With the pneumatic outlet valve 44 closed, compressed gas within the pump chamber 38 is prevented from flowing out of the pump chamber 38 through the pneumatic outlet passage 50. The closed pneumatic outlet valve 44 also prevents liquid from unintentionally entering the pneumatic outlet passage 50. It should be understood that in some examples, the landfill pump 10 does not include the pneumatic outlet valve 44. Conversely, when compressed gas is allowed to pass through the pneumatic inlet valve 42 during the venting phase, the flow restriction provided by the throttle orifice 52 still allows pressure to build up within the pump chamber 38. The rate at which gas is released through the throttle orifice 52 is less than the rate at which gas enters through the pneumatic inlet valve 42. Thus, the landfill pump 10 is configured to pump landfill liquid with or without the pneumatic outlet valve 44.

[0067] The evacuation of liquid causes a decrease in the liquid level within pump chamber 38, which in turn causes float 26 to move downwards. Float 26, reaching its lower stroke limit, actuates valve assembly 32 back to the filled state, which closes pneumatic inlet valve 42 to prevent further release of pressurized gas into pump chamber 38. Pneumatic inlet valve 42 switches back to the closed state and pneumatic outlet valve 44 switches back to the open state. The open pneumatic outlet valve 44 fluidly connects pneumatic outlet passage 50 to pump chamber 38. The closed pneumatic inlet valve 42 blocks the flow of compressed gas into pump chamber 38. Pneumatic outlet valve 44 is actuated to the open state, which fluidly connects pump chamber 38 to pneumatic outlet passage 50, thereby allowing compressed gas to be discharged from pump chamber 38. The open pneumatic outlet valve 44 allows any remaining pressurized gas in pump chamber 38 to be discharged from pump chamber 38. Compressed gas in pump chamber 38 is released through throttle orifice 52, and landfill liquid can be refilled into pump chamber 38 to start another pump cycle. When liquid can move through liquid inlet 16 (through liquid inlet valve 30 and into pump chamber 38), landfill pump 10 switches to the filling stage to restart pump cycle.

[0068] The pressure difference between the interior of pump chamber 38 and the pressure of the landfill well in which landfill pump 10 is located allows the compressed gas within pump chamber 38 to continue expanding, even when pneumatic inlet valve 42 is closed and pneumatic outlet valve 44 is open. Pneumatic outlet valve 44 slowly releases the compressed gas from pump chamber 38, preventing the pressure within pump chamber 38 from immediately equalizing when pneumatic outlet valve 44 is open. Even with pneumatic inlet valve 42 closed, the continued expansion of the compressed gas within pump chamber 38 can continue to drive the landfill liquid into discharge pipe 24 and out of landfill pump 10. This configuration allows for the use of less compressed gas to evacuate landfill pump 10, thus providing cost and energy savings.

[0069] Landfill pump 10 offers significant advantages. The throttle orifice 52 regulates the discharge of compressed gas from the pump chamber 38, thereby slowing the outflow of this compressed gas. Slowing the outflow of compressed gas from the pump chamber 38 slows the filling of the landfill pump 10, thus providing a slower circulation of the landfill pump 10. Extending the filling time of the landfill pump 10 and slowing its circulation provides a more consistent outflow, facilitating the periodic disposal of contaminated landfill liquid and reducing operator costs. The landfill pump 10 includes a pneumatic outlet valve 44 that closes the flow path through the pneumatic outlet passage 50 during the evacuation phase, thereby providing effective pressurization of the pump chamber 38 and driving the landfill liquid from the pump chamber 38.

[0070] Figure 4 It is along Figure 1The image shows a cross-sectional view of the landfill pump 10, taken from line 4-4. It illustrates the housing 12, manifold 14, liquid inlet 16, liquid outlet 18, discharge pipe 24, float 26, control lever 28, liquid inlet valve 30, valve assembly 32, filter 34, liquid outlet valve 44, liquid outlet passage 48, and liquid fitting 54 of the landfill pump 10. The discharge pipe 24 includes a port 36. The control lever 28 includes an upper stop 84, a lower stop 86, and a guide body 88.

[0071] A float 26 is disposed within the housing 12 and configured to rise and fall in response to changes in the liquid level within the landfill pump 10. The float 26 is disposed at least partially around the discharge pipe 24 and is configured to move axially relative to the discharge pipe 24. In the example shown, the float 26 is configured to move axially along the pump axis PA; however, it should be understood that not all examples are limited to this. The float 26 is configured to actuate the valve assembly 32 between a filling state and a discharge state.

[0072] Control lever 28 is connected to valve assembly 32. In the example shown, float 26 is configured to actuate valve assembly 32 between a filled state and a discharged state via control lever 28. Control lever 28 is connected to valve assembly 32 and extends through float 26. In the example shown, control lever 28 is connected to assembly base 82 of valve assembly 32.

[0073] A guide body 88 extends from the valve assembly 32 and passes through the float 26. The float 26 is movable relative to the guide body 88 as it moves within the housing 12. An upper stop 84 is supported by the guide body 88. The upper stop 84 limits the upward travel limit of the float 26 along the control rod 28. A lower stop 86 is supported by the guide body 88. The lower stop 86 limits the downward travel limit of the float 26 along the control rod 28.

[0074] In the example shown, the lower stop 86 includes a stop housing 90, a stop body 94, and a stop spring 92. The stop housing 90 is connected to a guide body 88. The stop spring 92 is disposed within the stop housing 90 and configured to bias the stop body 94 toward the float 26. The stop body 94 is at least partially disposed within the stop housing 90. The stop body 94 can be biased away from the stop body 94 by the stop spring 92. The stop body 94 can be configured to extend and retract relative to the stop housing 90 such that the float 26 can drive the stop body 94 into the stop housing 90, thereby compressing the stop spring 92, and the stop spring 92 can bias the stop body 94 out of the stop housing 90 as the float 26 rises away from the lower stop 86 with the rising liquid level.

[0075] As can be seen, valve assembly 32 includes a counterweight 96 for balancing control lever 28. Valve assembly 32 can be pivoted relative to discharge pipe 24 between a filling state and a discharging state, such as by moving control lever 28 via float 26 by means of upper stop 84 or lower stop 86. When valve assembly 32 is switched to the discharging state, valve assembly 32 can pivot to allow compressed gas to enter pump chamber 38 to begin the venting phase. When switching back to the filling phase, valve assembly 32 can switch to the filling state, in which the flow of compressed gas into pump chamber 38 is cut off. When valve assembly 32 is in the filling state, pneumatic outlet valve 44 is open. When valve assembly 32 is switched to the discharging state, valve assembly 32 can pivot during the venting phase to close the venting path through pneumatic outlet passage 50. When switching back to the filling phase, valve assembly 32 can switch to the filling state, in which compressed gas can be discharged from pump chamber 38.

[0076] When the landfill pump 10 is in the filling stage, the float 26 rises with the rising liquid level. The float 26 rises until it contacts the upper stop 84. The continued rise of the float 26 causes the control lever 28 to actuate the valve assembly 32 to the discharge state, in which the pneumatic inlet valve 42 opens to allow liquid to be discharged from the pump chamber 38. In this way, the float 26 can actuate the valve assembly 32 to the discharge state by means of the upper stop 84.

[0077] During the evacuation phase, float 26 descends with the decreasing liquid level. As float 26 disengages from upper stop 84 and begins to fall into housing 12, counterweight 96 holds valve assembly 32 in the filled state. Float 26 continues to move downwards and contacts lower stop 86. Float 26 causes control lever 28 to actuate valve assembly 32 back to the filled state via lower stop 86, thereby stopping compressed gas from entering pump chamber 38.

[0078] In the example shown, float 26 is configured to contact the stop body 94 of the lower stop 86. Float 26 can drive the stop body 94 downward against the stop spring 92, thereby compressing the stop spring 92 within the stop housing 90. The stop spring 92 and the stop body 94 resist downward movement of float 26 to slow it down before it reaches the stop housing 90, thus preventing undesirable impact damage between float 26 and the lower stop 86.

[0079] In the example shown, float 26 can travel along control lever 28 between upper stop 84 and lower stop 86. During the purging cycle, liquid in pump chamber 38 is driven through port 36 into discharge pipe 24, then upward along discharge pipe 24 and exiting liquid outlet valve 44. Compressed gas is allowed to enter pump chamber 38 during the purging phase to drive landfill liquid downward between housing 12 and discharge pipe 24, through port 36 into discharge pipe 24, and then upward along discharge pipe 24 and exiting landfill pump 10 through liquid outlet valve 44. Float 26 descends until stopped by lower stop 86, the contact between lower stop 86 and float 26 actuating valve assembly 32 to a filled state, thereby closing pneumatic inlet valve 42.

[0080] When valve assembly 32 is actuated to a filled state to stop the flow of compressed gas into pump chamber 38, lower stop 86 spacees float 26 from port 36. The pressure difference between the interior of pump chamber 38 and the pressure within the wellbore where the packing pump 10 is located allows the compressed gas in pump chamber 38 to continue expanding, even when pneumatic inlet valve 42 is closed and pneumatic outlet valve 44 is open. Pneumatic outlet valve 44 slowly releases compressed gas from pump chamber 38 due to throttle orifice 52, preventing the pressure in pump chamber 38 from immediately equalizing when pneumatic outlet valve 44 is open. Gas expands within an expansion chamber 98 formed between float 26 and port 36. This expansion chamber 98 is a portion of pump chamber 38 between float 26 and port 36. When float 26 is at its lower end along control rod 28, length L2 extends between port 36 and float 26. Expansion chamber 98 has a length L2. The length L3 is between the port 36 and the bottom side 78 of the manifold 14, and forms the length of the pump chamber 38 between the manifold 14 and the port 36.

[0081] After the flow of compressed gas into pump chamber 38 is cut off, the expansion of the compressed gas within pump chamber 38 can continue to drive the landfill fluid into discharge pipe 24 and out of landfill pump 10. A spaced-out expansion chamber 98 between float 26 and port 36 provides a larger volumetric area for gas expansion. The larger volume of expansion chamber 98 allows gas expansion to balance the pressure between pump chamber 38 and the wellbore, and allows landfill fluid to flow in through fluid inlet valve 30.

[0082] Float 26 causes valve assembly 32 to switch to the filled state before float 26 reaches port 36. The inflow of compressed gas is cut off before pump chamber 38 has been substantially emptied. Even after valve assembly 32 has switched to the filled state, expansion chamber 98 allows the compressed gas already allowed into pump chamber 38 to expand and continue to expel landfill liquid. Thus, landfill pump 10 can remain in the emptying phase and continue discharging landfill liquid without additional inflow of compressed gas.

[0083] In the example shown, the expansion chamber 98 has a length L2, while the pump chamber 38 has a length L3 between the port 36 and the manifold 14. Thus, length L3 forms the distance between the port 36 and the top of the pump chamber 38. The ratio between the length L2 of the expansion chamber 98 and the length L3 of the pump chamber 38 between the port 36 and the manifold 14 can be approximately 5:1. In some examples, the ratio between length L2 and length L3 can be approximately 4:1. In some examples, the ratio between length L2 and length L3 can be approximately 4:1. In some examples, the ratio between length L2 and length L3 can be approximately 3:1. In some examples, length L2 can be at least 25% of length L3. In some examples, length L2 can be at least 30% of length L3. In some examples, length L2 can be at least 35% of length L3. The ratio between length L2 and length L3 positions the float 26 such that the expansion chamber 98 can contain the gas to flow upward along the discharge pipe 24 before the expanding gas reaches the port 36. The expansion chamber 98 allows the compressed gas to expand and continue to expel the liquid, without the gas flowing into port 36 and upward through discharge pipe 24 into the discharge line extending from the liquid fitting 54, as it would be disadvantageous for the gas to enter such a discharge line.

[0084] Restricting the downward travel of float 26 to create expansion chamber 98 provides significant advantages. As discussed above, throttle orifice 52 restricts gas flow from pump chamber 38 to slow the circulation of landfill pump 10. The downward travel of float 26 is restricted such that float 26 is spaced apart from port 36 by a length L2. Therefore, expansion chamber 98 can hold a larger volume of liquid compared to an example where float 26 continues downward to port 36. Furthermore, float 26 causes valve assembly 32 to actuate to the filling state more quickly, thereby stopping the inflow of compressed gas. Expansion chamber 98 allows gas to expand without exiting through discharge pipe 24. Restricting the downward travel of float 26 also causes pneumatic inlet valve 42 to close earlier. Even with pneumatic inlet valve 42 closed, pressurized gas is restricted from freely exiting through pneumatic outlet passage 50 and can therefore continue to expand to continue expelling landfill liquid from landfill pump 10. This configuration allows for less gas usage, thereby reducing costs and wear and tear and improving operational efficiency.

[0085] Figure 5 This is a cross-sectional view of manifold 14, with all mating parts removed. It shows the pneumatic passage 68a, pneumatic passage 68b, liquid passage 70, top side 80, bottom side 78, sealing groove 100, manifold cap 102, and vent barrier 76 of manifold 14. It shows the inlet mating hole 104 and inlet valve hole 106 of pneumatic passage 68a. It shows the outlet mating hole 74, outlet valve hole 72, and throttle orifice 52 of pneumatic passage 68b.

[0086] Manifold 14 is configured to abut against housing 12 of landfill pump 10. Sealing groove 100 may support a seal (such as an O-ring seal). Manifold cap 102 may extend above a portion of housing 12 to limit the insertion limit of manifold 14 into housing 12. Pneumatic passage 68a is formed through manifold 14 and opens through top side 80 and bottom side 78 of manifold 14. As discussed above, pneumatic passage 68a allows pressurized gas to flow into pump chamber 38. Pneumatic inlet passage 46 extends through pneumatic passage 68a.

[0087] The inlet mating hole 104 opens through the top side 80 of the manifold 14. The inlet mating hole 104 is configured to mate with the pneumatic fitting 56a. In the example shown, the inlet mating hole 104 is a threaded hole configured to mate with the threaded portion of the pneumatic fitting 56a to connect the pneumatic fitting 56a to the manifold 14.

[0088] The inlet valve port 106 opens through the bottom side 78 of the manifold 14. The inlet valve port 106 is configured to support a portion of the pneumatic inlet valve 42. In the example shown, the inlet valve port 106 is configured to support the inlet valve seat 62 of the pneumatic inlet valve 42. In the example shown, the inlet valve port 106 is a threaded hole configured to mate with a threaded portion of the pneumatic inlet valve 42 (such as a threaded housing or other support for the inlet valve seat 62) to connect that portion of the pneumatic inlet valve 42 to the manifold 14.

[0089] The pneumatic passage 68b is formed through the manifold 14 and opens through the top side 80 and bottom side 78 of the manifold 14. As discussed above, the pneumatic passage 68b allows pressurized gas to flow out of the pump chamber 38.

[0090] The outlet mating hole 74 opens through the top side 80 of the manifold 14. The outlet mating hole 74 is configured to mate with the pneumatic fitting 56b. In the example shown, the outlet mating hole 74 is a threaded hole configured to mate with the threaded portion of the pneumatic fitting 56b to connect the pneumatic fitting 56b to the manifold 14.

[0091] The outlet valve port 72 opens through the bottom side 78 of the manifold 14. The outlet valve port 72 is configured to support a portion of the pneumatic outlet valve 44. In the example shown, the outlet valve port 72 is configured to support the discharge mating member 58 of the outlet valve seat 66 forming the pneumatic outlet valve 44. In the example shown, the outlet valve port 72 is a threaded hole configured to mate with the threaded portion of the discharge mating member 58 to connect the discharge mating member 58 to the manifold 14.

[0092] A vent barrier 76 is disposed in the pneumatic passage 68b and defines a narrowing portion of the pneumatic passage 68b. The vent barrier 76 is axially positioned between the outlet mating hole 74 and the outlet valve hole 72 along the passage axis OCA of the pneumatic passage 68b. The vent barrier 76 defines a throttle orifice 52, which forms a fluid flow path between the outlet valve hole 72 and the outlet mating hole 74. The vent barrier 76 is integrally formed with other portions of the manifold 14, such as portions of the manifold 14 defining other portions of the pneumatic passage 68b. However, it should be understood that not all examples are so limited. For example, the vent barrier 76 may be formed separately from and mounted to the manifold 14. In one such example, the vent barrier 76 may include external threads configured to engage with threads within the pneumatic passage 68b to connect the vent barrier 76 (and thus the throttle orifice 52) to the manifold 14.

[0093] The throttle orifice 52 extends axially completely through the vent barrier 76 along the channel axis CA. As shown, the diameter D1 of the throttle orifice 52 is smaller than the diameter D2 of the largest diameter portion of the pneumatic passage 68b. In some examples, the diameter D2 is at least twice the diameter D1. In some examples, the diameter D2 is at least three times the diameter D1. In some examples, the diameter D2 is at least ten times the diameter D1. The restriction provided by the throttle orifice 52 slows the discharge of gas from the pump chamber 38, thereby slowing the entry of landfill liquid into the pump chamber 38, thus slowing the circulation time of the landfill pump 10.

[0094] The liquid passage 70 extends through the manifold 14 and opens through the top side 80 and bottom side of the manifold 14. Drained liquid can flow through the liquid passage 70. In some cases, the drain pipe 24 may be attached to the manifold 14, and another fitting (such as a liquid fitting 54) may be attached to the liquid fitting hole 108 of the liquid passage 70.

[0095] Figure 6 It is used for landfill pumps (such as landfill pump 10 (in Figure 1 , Figure 2 , Figure 3A and Figure 4A cross-sectional view of the vent 110 (best visible in the middle). The vent 110 defines a throttle orifice 52 and is formed separately from the manifold of the landfill pump 10. In the example shown, the vent 110 is formed as a discharge fit, except that the throttle orifice 52 is integrated into the vent 110, which is substantially similar to the discharge fit 58 (in the middle). Figure 3B (Best visible in the middle). The discharge component 110 includes a mating body 112 and a mating passage 114. The mating body 112 includes a guide rod 116 and a cap 118. The mating passage 114 includes a receiving chamber 120 and a throttling orifice 52.

[0096] The mating body 112 defines a mating passage 114. The mating passage 114 is configured to form a pneumatic outlet passage 50 through which gas is discharged from the pump chamber 38 of the landfill pump 10. A receiving chamber 120 of the mating passage 114 is configured such that an outlet valve member 64 of the pneumatic outlet valve 44 can extend into the receiving chamber 120 to seal the mating passage 114 and prevent compressed gas flow through it. The portion of the mating body 112 defining the receiving chamber 120 can form an outlet valve seat 66 for the pneumatic outlet valve 44. A throttle orifice 52 extends from the mating passage 114.

[0097] In the example shown, the throttle orifice 52 is a narrowing portion of the passage 114. In the example shown, the throttle orifice 52 is formed as an opening through the structure of the vent 110. The throttle orifice 52 inhibits, but does not stop, the flow of pressurized gas from the pump chamber 38 through the pneumatic outlet passage 50. Thus, the throttle orifice 52 slows the circulation of the landfill pump 10 because liquid enters the pump chamber 38 only when the liquid pressure is nearly equal to the pressure inside the pump chamber 38. If pressurized gas remains in the pump chamber 38 after the purging phase, the residual pressurized gas will slow the entry of liquid into the pump chamber 38 through the liquid inlet 16, thereby making the filling phase of the pump circulation longer. This has the overall effect of slowing the circulation of the landfill pump 10, which is advantageous for applications requiring low circulation and low flow rates.

[0098] A guide rod 116 extends from the cap 118. The guide rod 116 is configured to extend into the manifold (similar to manifold 14 but without the integrated orifice 52) to connect the vent 110 to the manifold. The vent 110 is configured to be mounted to the manifold and restrict gas discharge from the landfill pump 10. For example, the vent 110 can be connected to the manifold via an interface between the mating body 112 and the manifold. For example, the guide rod 116 may include an external thread configured to engage with an internal thread within a bore in the manifold. However, it should be understood that the guide rod 116 can be mounted to the manifold in any desired manner, such as via a press-fit connection, bayonet connection, threaded connection, etc. The manifold with the vent 110 does not require an integrated orifice. Instead, the vent 110 includes an orifice 52 that restricts the flow of exhaust gas from the pump chamber 38. The throttle orifice 52 can form the narrowest diameter portion of the pneumatic outlet channel 50, which discharges gas from the internal pump chamber 38 of the landfill pump 10.

[0099] The vent 110 offers significant advantages. A throttle orifice 52 is integrated into the vent 110, which can be installed into a manifold. The throttle orifice 52 restricts the outflow of compressed gas from the pump chamber 38, thereby slowing the cycle time of the landfill pump 10. The vent 110 can be installed on existing manifolds to provide restricted circulation to landfill pumps that include such manifolds. Therefore, existing landfill pumps can be retrofitted by installing the vent 110 to provide efficient and stable circulation. Furthermore, the vent 110 can be removed from the pump cover 118, facilitating easy removal of the throttle orifice 52 for replacement or cleaning.

[0100] Figure 6 It is used for landfill pumps (such as landfill pump 10 (in Figure 1 , Figure 2 , Figure 3A and Figure 4 A cross-sectional view of the vent 110 (best visible in the middle). The vent 110 defines a throttle orifice 52 and is formed separately from the manifold of the landfill pump 10. In the example shown, the vent 110 is formed as a discharge fit, except that the throttle orifice 52 is integrated into the vent 110, which is substantially similar to the discharge fit 58 (in the middle). Figure 3B (Best visible in the middle). The discharge component 110 includes a mating body 112 and a mating passage 114. The mating body 112 includes a guide rod 116 and a cap 118. The mating passage 114 includes a receiving chamber 120 and a throttling orifice 52.

[0101] The mating body 112 defines a mating passage 114. The mating passage 114 is configured to form a pneumatic outlet passage 50 through which gas is discharged from the pump chamber 38 of the landfill pump 10. A receiving chamber 120 of the mating passage 114 is configured such that an outlet valve member 64 of the pneumatic outlet valve 44 can extend into the receiving chamber 120 to seal the mating passage 114 and prevent compressed gas flow through it. The portion of the mating body 112 defining the receiving chamber 120 can form an outlet valve seat 66 for the pneumatic outlet valve 44. A throttle orifice 52 extends from the mating passage 114.

[0102] In the example shown, the throttle orifice 52 is a narrowing portion of the passage 114. In the example shown, the throttle orifice 52 is formed as an opening through the structure of the vent 110. The throttle orifice 52 inhibits, but does not stop, the flow of pressurized gas from the pump chamber 38 through the pneumatic outlet passage 50. Thus, the throttle orifice 52 slows the circulation of the landfill pump 10 because liquid enters the pump chamber 38 only when the liquid pressure is nearly equal to the pressure inside the pump chamber 38. If pressurized gas remains in the pump chamber 38 after the purging phase, the residual pressurized gas will slow the entry of liquid into the pump chamber 38 through the liquid inlet 16, thereby making the filling phase of the pump circulation longer. This has the overall effect of slowing the circulation of the landfill pump 10, which is advantageous for applications requiring low circulation and low flow rates.

[0103] A guide rod 116 extends from the cap 118. The guide rod 116 is configured to extend into the manifold (similar to manifold 14 but without the integrated orifice 52) to connect the vent 110 to the manifold. The vent 110 is configured to be mounted to the manifold and restrict gas discharge from the landfill pump 10. For example, the vent 110 can be connected to the manifold via an interface between the mating body 112 and the manifold. For example, the guide rod 116 may include an external thread configured to engage with an internal thread within a bore in the manifold. However, it should be understood that the guide rod 116 can be mounted to the manifold in any desired manner, such as via a press-fit connection, bayonet connection, threaded connection, etc. The manifold with the vent 110 does not require an integrated orifice. Instead, the vent 110 includes an orifice 52 that restricts the flow of exhaust gas from the pump chamber 38. The throttle orifice 52 can form the narrowest diameter portion of the pneumatic outlet channel 50, which discharges gas from the internal pump chamber 38 of the landfill pump 10.

[0104] The vent 110 offers significant advantages. A throttle orifice 52 is integrated into the vent 110, which can be installed into a manifold. The throttle orifice 52 restricts the outflow of compressed gas from the pump chamber 38, thereby slowing the cycle time of the landfill pump 10. The vent 110 can be installed on existing manifolds to provide restricted circulation to landfill pumps that include such manifolds. Therefore, existing landfill pumps can be retrofitted by installing the vent 110 to provide efficient and stable circulation. Furthermore, the vent 110 can be removed from the pump cover 118, facilitating easy removal of the throttle orifice 52 for replacement or cleaning.

[0105] Figure 7 It is used for landfill pumps (such as landfill pump 10 (in Figure 1 , Figure 2 , Figure 3A and Figure 4 A cross-sectional view of the vent 122 (best visible in the middle). The vent 122 is substantially similar to the vent 110 (see...). Figure 6 Because the vent 122 includes an integrated throttle orifice 52 and is formed separately from the manifold of the landfill pump 10. The vent 122 includes a mating body 124 and a mating passage 126. The mating body 124 includes a mounting end 128 and an outer end 130. The mating passage 126 includes the throttle orifice 52.

[0106] The mating body 124 defines the mating passage 126. The mating passage 126 is configured to form a pneumatic outlet passage 50 through which gas is discharged from the pump chamber 38 of the landfill pump 10. The throttle orifice 52 forms part of the mating passage 126.

[0107] In the example shown, the throttle orifice 52 is a narrowing portion of the passage 126. In the example shown, the throttle orifice 52 is formed as an opening through the structure of the vent 122. The throttle orifice 52 inhibits, but does not stop, the flow of pressurized gas from the pump chamber 38 through the pneumatic outlet passage 50. Thus, the throttle orifice 52 slows the circulation of the landfill pump 10 because liquid enters the pump chamber 38 only when the liquid pressure is nearly equal to the pressure inside the pump chamber 38.

[0108] Mounting end 128 is configured to mate with a manifold (similar to manifold 14 but without integrated throttle port 52) ​​for connection to the manifold. Outer end 130 is located at the end of mating body 124 opposite to mounting end 128. Outer end 130 is configured to mate with a hose, allowing vent 122 to discharge gas to the hose. It should be understood that in some examples, outer end 130 may not be connected to a hose, allowing gas to be discharged through vent 122 and directly into the wellbore in which the packing pump 10 is located.

[0109] The vent 122 is configured to be installed into the manifold and restrict gas discharge from the landfill pump. The vent 122 is configured to be installed into the pneumatic outlet passage 50 of the manifold (such as replacing the pneumatic fitting 56b in...). Figure 3B (Best visible in the middle). For example, the vent 122 can be connected to the manifold via an interface between the mating body 124 and the manifold. For example, the mounting end 128 may include an external thread configured to engage with an internal thread within a bore through the manifold. However, it should be understood that the mounting end 128 can be mounted to the manifold in any desired manner, such as via a press-fit connection, bayonet connection, threaded connection, etc. The manifold with the vent 122 does not require an integrated throttling orifice. Instead, the vent 122 includes a throttling orifice 52 that restricts the flow of exhaust gas from the pump chamber 38. The throttling orifice 52 may form the narrowest diameter portion of the pneumatic outlet passage 50.

[0110] The vent 122 offers significant advantages. An orifice 52 is integrated into the vent 122, which can be removably mounted to a manifold. The orifice 52 restricts the outflow of compressed gas from the pump chamber 38, thereby slowing the cycle time of the landfill pump 10. The vent 122 can be installed on existing manifolds to provide restricted circulation to landfill pumps that include such manifolds. Therefore, existing landfill pumps can be retrofitted by installing the vent 122 to provide efficient and stable circulation. Furthermore, the vent 122 can be removable from the manifold, facilitating easy removal of the orifice 52 for replacement or cleaning.

[0111] Figure 8 This is an enlarged isometric view of manifold 14', showing the vent 132 separated from manifold 14'. Vent 132 is substantially similar to vent 110 (see [reference]). Figure 6 ) and venting component 122 (see Figure 7 Because the vent 132 includes a throttle orifice 52 that restricts gas flow through the vent 132, wherein the throttle orifice 52 is not integrated into the manifold 14'. The vent 132 includes a vent housing 134 and a vent barrier 136. The throttle orifice 52 is formed by the vent barrier 136. The vent housing 134 can be mounted into the manifold 14' (such as within a pneumatic outlet passage of a pneumatic passage 68b similar to that of the manifold 14). In some examples, the vent 132 can be mounted into a mating part connected to the manifold 14', such as into a pneumatic mating part 68b. The vent housing 134 can be configured to be mounted in any desired manner, such as by engaging threads, bayonet connections, press fits, etc.

[0112] The discharge barrier 136 is connected to the discharge housing 134. In some examples, the discharge barrier 136 may be integrally formed with the discharge housing 134. In the example shown, the discharge barrier 136 is connected to the discharge housing 134 via engaging threads therebetween. In the example shown, the discharge barrier 136 may be independently connected to the discharge housing 134. In the example shown, the discharge barrier 136 can be considered to form a retaining screw having a through-hole forming a throttle orifice 52. The throttle orifice 52 is formed by the discharge barrier 136.

[0113] In some examples, the vent barrier 136 is removable from and replaceable from the vent housing 134. Multiple different vent barriers 136, with corresponding orifices of different sizes to form choke ports 52 of different sizes, can be selectively placed within the vent housing 134 to allow for tailoring of the throttling of the discharge to regulate the circulation rate of the burial pump. In this way, the choke port 52 can still be located within the wellbore to properly vent pressurized gas from the pump chamber 38 of the burial pump, without being integrated inside the manifold 14'.

[0114] Although the invention has been described with reference to exemplary embodiments(s), those skilled in the art will understand that various changes can be made and equivalents can be used to replace elements therein without departing from the scope of the invention. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of the invention without departing from the basic scope of the invention. Therefore, it is intended that the invention is not limited to the specific embodiments(s) disclosed, but rather that the invention may include all embodiments falling within the scope of the appended claims. Any single feature or any combination of features from one embodiment shown herein may be used in different embodiments of other features shown independently of those shown herein. Therefore, the scope of the invention and any of its claims is not limited to the embodiments and / or combinations of features shown herein, but may include any combination of one, two, or more features shown herein.

Claims

1. A landfill pump for pumping liquid out of a wellbore in a landfill, the landfill pump comprising: case; A pump chamber, which is at least partially located within the housing; A liquid inlet configured to allow liquid to flow from the outside of the landfill pump into the pump chamber; A liquid outlet channel through which liquid is discharged; A valve assembly configured to regulate the gas flow entering the pump chamber to force liquid within the pump chamber to be discharged through the liquid outlet; and A pneumatic outlet channel is configured to discharge pneumatic gas from the pump chamber, wherein a throttle orifice is positioned along the pneumatic outlet channel to slow the circulation of the landfill pump by slowing the discharge of the gas from the pump chamber and thus slowing the inflow of liquid into the pump chamber.

2. The landfill pump as described in claim 1, wherein, The landfill pump is configured to undergo multiple pump cycles, each pump cycle including a filling phase and a venting phase. In the filling phase, liquid flows into the pump chamber through the liquid inlet, and in the venting phase, the valve assembly releases gas under pressure into the pump chamber to force liquid out through the liquid outlet channel.

3. The landfill pump as described in claim 2, wherein, During the filling phase, the throttle orifice slows down the discharge of gas from the pump chamber.

4. The landfill pump as described in any one of claims 2 and 3, wherein, During the entire filling phase, the throttle orifice is fluidly connected to the pump chamber.

5. The landfill pump as described in any one of claims 2 to 4, wherein, During the venting phase, gas does not flow out of the pump chamber through the pneumatic outlet channel.

6. The landfill pump as claimed in any one of claims 2 to 5, wherein, During the filling phase, the throttle orifice slows down the discharge of gas remaining from the venting phase due to the residual pressure in the pump chamber.

7. The landfill pump as claimed in any one of claims 2 to 6, wherein, During the filling phase, the throttle orifice slows the discharge of gas from the pump chamber, which is discharged from the pump chamber as liquid enters the chamber.

8. The landfill pump as claimed in any of the preceding claims, wherein, The throttling orifice narrows the pneumatic outlet channel to an opening with a diameter of 0.1 inches or less.

9. The landfill pump as claimed in any of the preceding claims, wherein, The throttling orifice narrows the pneumatic outlet channel to an opening with a diameter of 0.05 inches or less.

10. The landfill pump as claimed in any of the preceding claims, wherein, The pneumatic outlet channel has an inner diameter of at least 0.2 inches along most of its length.

11. The landfill pump as claimed in any of the preceding claims, wherein, The pneumatic outlet channel has an inner diameter of at least 0.2 inches along its entire length, except for the portion along the narrower throttle orifice.

12. The landfill pump as claimed in any of the preceding claims, the landfill pump further comprising a manifold, each of the liquid outlet passage and the pneumatic outlet passage extending within the manifold.

13. The landfill pump as claimed in claim 12, wherein, The throttling orifice is installed on the manifold.

14. The landfill pump as claimed in claim 13, wherein, The throttling orifice is located within the venting component attached to the manifold.

15. The landfill pump as claimed in claim 14, wherein, The venting element includes a venting barrier that forms the throttling orifice.

16. The landfill pump as claimed in any of the preceding claims, wherein, The throttling orifice is located inside the manifold.

17. The landfill pump as claimed in any of the preceding claims, wherein, The valve assembly includes a pneumatic outlet valve configured to block the pneumatic outlet passage during the entry of compressed gas into the pump chamber via the pneumatic inlet valve, thereby displacing liquid from the pump chamber via the liquid outlet, and wherein the pneumatic outlet valve is moved to prevent the pneumatic outlet passage from being blocked during the filling of the pump chamber by liquid via the liquid inlet.

18. The landfill pump as claimed in any of the preceding claims, wherein, The landfill pump includes a pneumatic inlet channel that guides a pressurized gas flow into the chamber to drive liquid to flow out of the pump chamber through the liquid outlet.

19. The landfill pump as claimed in claim 18, wherein, The valve assembly includes a pneumatic inlet valve that blocks the pneumatic inlet passage while liquid is filling the pump chamber through the liquid inlet, and is moved to prevent the pneumatic inlet passage from being blocked while compressed gas enters the pump chamber through the pneumatic inlet valve to drive liquid out of the pump chamber through the liquid outlet.

20. The landfill pump of any of the preceding claims further includes a float that rises and falls in the pump chamber in response to a change in the liquid level in the chamber, such movement of the float actuating the valve assembly between a filling state and a discharging state, the valve assembly allowing compressed gas to enter the pump chamber in the discharging state and preventing compressed gas from entering the pump chamber in the filling state.

21. The landfill pump as claimed in any of the preceding claims, further comprising a liquid inlet valve, the liquid inlet valve being open to allow liquid to flow from the liquid inlet into the pump chamber, and the liquid inlet valve being closed to prevent liquid in the pump chamber from flowing back out of the liquid inlet.

22. The landfill pump as claimed in any of the preceding claims further includes a discharge pipe extending axially within the housing along the pump axis and within the pump chamber, the liquid outlet passage extending at least partially within the discharge pipe.

23. The landfill pump as claimed in any of the preceding claims further includes a liquid outlet valve, which opens to allow liquid to flow out of the pump chamber through the liquid outlet, and closes to prevent liquid from flowing through the liquid outlet and returning to the pump chamber.

24. The landfill pump as claimed in any one of claims 1 to 19, further comprising: A float configured to axially displace along the pump axis to actuate the valve assembly between a filling state and a discharging state, wherein in the filling state the pneumatic inlet passage is fluidly disconnected from the pump chamber, and in the discharging state the pneumatic inlet passage is fluidly connected to the pump chamber; A discharge pipe having at least one port formed through the discharge pipe, the discharge pipe being configured to deliver liquid to the liquid outlet; and A control lever, which is connected to the float, the control lever including an upper stop and a lower stop, the upper stop limiting the upward travel limit of the float along the control lever, and the lower stop limiting the downward travel limit of the float along the control lever; The float causes the control lever to actuate the valve assembly to the discharge state via the upper stop.

25. The landfill pump as claimed in claim 24, wherein, The float causes the control lever to actuate the valve assembly to the filled state via the lower stop.

26. The landfill pump as claimed in any one of claims 24 and 25, wherein: The pump chamber includes a venting chamber, which is axially disposed between the lower stop and the at least one port; The venting chamber has a first axial length, and the pump chamber has a second axial length between the at least one port and the liquid outlet; and The first axial length is at least one-quarter of the second axial length to provide a volumetric space for compressed gas to expand into the pump chamber and to continue to expel liquid from the pump chamber after the valve assembly is actuated to the filled state.

27. The landfill pump as claimed in claim 26, wherein, The first axial length is at least 30% of the second axial length.

28. The landfill pump as claimed in claim 26, wherein, The first axial length is at least one-third of the second axial length.

29. The landfill pump as claimed in any one of claims 26 to 28, wherein, The lower stop includes: A stop housing, the stop housing being connected to the guide body of the control lever; A stop spring, said stop spring being at least partially disposed within the stop housing; and A stop body, which is biased toward the float by the stop spring, is at least partially disposed within the stop housing; The stop body is configured to contact the float when the float falls into the pump chamber as the liquid level drops, causing the stop spring to be compressed, and the lower stop slows down the downward movement of the float before stopping its downward movement.

30. A landfill pump for pumping liquid out of a wellbore in a landfill, the landfill pump comprising: case; A pump chamber, which is at least partially located within the housing; A manifold, which is disposed at the top of the housing; A liquid inlet configured to allow liquid to flow from the outside of the landfill pump within the wellbore into the pump chamber; A liquid outlet channel, which is formed at least partially through the manifold, through which liquid is discharged; A valve assembly configured to regulate the flow of compressed gas into the pump chamber to force liquid within the chamber to be discharged through the liquid outlet; and A pneumatic outlet channel is configured to discharge pneumatic gas from the chamber, wherein a throttle orifice is positioned along the pneumatic outlet channel to slow down the circulation of the landfill pump by slowing the discharge of the gas from the pump chamber and thus slowing the inflow of liquid into the pump chamber. The throttling orifice is formed in a venting component connected to the manifold.

31. The landfill pump as claimed in claim 30, wherein, The vent is connected to the manifold via the top side of the manifold, the top side of which is oriented away from the pump chamber.

32. The landfill pump as claimed in claim 31, wherein, The venting element forms a pneumatic fitting connected to the manifold.

33. The landfill pump as claimed in claim 32, wherein, The pneumatic fitting is configured to connect to a hose for the exhaust gas extending from the landfill pump.

34. The landfill pump according to any one of claims 31 to 33, wherein, The throttling orifice is formed as a hole passing through the structure of the venting element.

35. The landfill pump as claimed in claim 30, wherein, The vent is connected to the manifold via the bottom side of the manifold, which is oriented toward the pump chamber.

36. The landfill pump as claimed in claim 35, wherein, The venting element forms a discharge fitting connected to the manifold, wherein the outlet valve member of the pneumatic outlet valve of the valve assembly extends at least partially into the discharge fitting.

37. The landfill pump as claimed in claim 36, wherein, The discharge fitting forms a valve seat for the pneumatic outlet valve.

38. The landfill pump according to any one of claims 35 to 37, wherein, The throttling orifice is formed as a hole passing through the structure of the venting element.

39. The landfill pump according to any one of claims 30 to 38, wherein, The venting component includes a venting housing and a venting barrier, with the throttling orifice formed through the venting barrier, which can be independently connected to the venting housing.

40. The landfill pump as claimed in claim 39, wherein, The venting barrier is connected to the venting housing via engaging threads.

41. A landfill pump for pumping liquid out of a wellbore in a landfill, the landfill pump comprising: case; A pump chamber, which is at least partially located within the housing; A manifold, which is disposed at the top of the housing; A liquid inlet configured to allow liquid to flow from the outside of the landfill pump within the wellbore into the pump chamber; A liquid outlet channel through which liquid is discharged; A valve assembly configured to regulate the flow of compressed gas into the pump chamber to force liquid within the chamber to be discharged through the liquid outlet; and A pneumatic outlet passage, formed at least partially through the manifold, is configured to discharge pneumatic gas from the chamber, wherein a throttle orifice is positioned along the pneumatic outlet passage to slow the circulation of the landfill pump by slowing the discharge of the gas from the pump chamber and thus slowing the entry of the liquid into the pump chamber, the throttle orifice being formed as an orifice through the structure of the manifold.

42. The landfill pump as claimed in claim 41, wherein: The manifold includes an outlet passage that extends completely through the manifold between a top side of the manifold oriented away from the pump chamber and a bottom side of the manifold oriented towards the pump chamber, and the pneumatic outlet passage extends within the outlet passage. and The outlet passage includes at least one threaded hole and the throttle orifice.

43. The landfill pump as claimed in claim 42, wherein, The at least one threaded hole is disposed between the top side and the throttling orifice.

44. The landfill pump as claimed in claim 42, wherein, The at least one threaded hole is disposed between the bottom side and the throttling orifice.

45. The landfill pump as claimed in claim 42, wherein, The at least one threaded hole includes: A valve port, opening through the bottom side of the manifold, is configured to mate with a portion of a pneumatic outlet valve to connect that portion of the pneumatic outlet valve to the manifold; and A mating hole, which opens through the top side of the manifold, is configured to mate with a pneumatic fitting to connect the pneumatic fitting to the manifold.

46. ​​The landfill pump according to any one of claims 42 to 45, wherein: The manifold includes an inlet passage that extends completely through the manifold between its top and bottom sides; and A pneumatic inlet passage configured to supply the compressed gas to the pump chamber extends within the inlet passage.

47. A landfill pump for pumping liquid out of a wellbore in a landfill, the landfill pump comprising: case; A pump chamber, which is at least partially located within the housing; A liquid inlet configured to allow liquid to flow from the outside of the landfill pump within the wellbore into the pump chamber; A liquid outlet channel through which liquid is discharged; A valve assembly configured to regulate the flow of compressed gas into the pump chamber to force liquid within the pump chamber to flow out through the liquid outlet; and A pneumatic inlet channel configured to supply compressed gas to the pump chamber; A pneumatic outlet passage configured to discharge compressed gas from the chamber; A float configured to axially displace along the pump axis to actuate the valve assembly between a filling state and a discharging state, wherein in the filling state the pneumatic inlet passage is fluidly disconnected from the pump chamber, and in the discharging state the pneumatic inlet passage is fluidly connected to the pump chamber; A discharge pipe having at least one port formed through the discharge pipe, the discharge pipe being configured to deliver liquid to the liquid outlet; and A control lever, which is connected to the float, the control lever including an upper stop and a lower stop, the upper stop limiting the upward travel limit of the float along the control lever, and the lower stop limiting the downward travel limit of the float along the control lever; The float is configured to enable the control lever to actuate the valve assembly to the discharge state via the upper stop, and the float is configured to enable the control lever to actuate the valve assembly to the filling state via the lower stop. The pump chamber includes a venting chamber axially disposed between the lower stop and the at least one port, the venting chamber having a first axial length, and the pump chamber having a second axial length between the at least one port and the liquid outlet; and Wherein, when the float is at the downward stroke limit and the valve assembly is in the filled state, the first axial length is at least one-quarter of the second axial length, to provide a volumetric space between the float and the at least one port for allowing compressed gas to enter the pump chamber when the valve assembly is in the discharged state, so as to expand the valve assembly after it is actuated to the filled state and continue to drive liquid out of the pump chamber.

48. The landfill pump as claimed in claim 47, wherein, The throttle orifice is positioned along the pneumatic outlet channel to slow the circulation of the landfill pump by slowing the discharge of gas from the pump chamber and thus slowing the entry of liquid into the pump chamber.

49. The landfill pump of claim 48, further comprising: A pneumatic outlet valve is actuated between an open state and a closed state. In the open state, the pneumatic outlet valve fluidly connects the pump chamber and the pneumatic outlet channel, and in the closed state, the pneumatic outlet valve fluidly disconnects the pump chamber and the pneumatic outlet channel. The pneumatic outlet valve is in the closed state when the valve assembly is in the discharge state, and the pneumatic outlet valve is in the open state when the valve assembly is in the filling state.

50. The landfill pump according to any one of claims 47 to 49, wherein, The first axial length is at least 30% of the second axial length.

51. The landfill pump according to any one of claims 47 to 50, wherein, The first axial length is at least one-third of the second axial length.

52. The landfill pump according to any one of claims 47 to 51, wherein, The lower stop includes: A stop housing, the stop housing being connected to the guide body of the control lever; A stop spring, said stop spring being at least partially disposed within the stop housing; and A stop body, which is biased toward the float by the stop spring, is at least partially disposed within the stop housing; The stop body is configured such that when the float falls into the pump chamber with the descending liquid level, it contacts the float, causing the spring to be compressed, and the lower stop slows down the downward movement of the float before stopping its downward movement.

53. A method of circulating a landfill pump, the landfill pump being configured to pump liquid from a wellbore in a landfill, the method comprising: With the valve assembly of the landfill pump in the discharge state, a compressed gas flow is allowed to enter the pump chamber from the pneumatic inlet channel of the landfill pump. The compressed gas drives the liquid to flow downward in the pump chamber, and then upward along the distribution pipe, and flows out through the liquid outlet of the landfill pump. The valve assembly is actuated to a filling state, in which the flow of compressed gas to the pump chamber is cut off; and The outflow of compressed gas from the pump chamber is restricted by a throttle orifice located in the pneumatic outlet channel of the landfill pump, thereby slowing down the circulation of the landfill pump by slowing down the outflow of compressed gas from the pump chamber and thus slowing down the inflow of liquid into the pump chamber.

54. A method of circulating a landfill pump, the landfill pump being configured to pump liquid from a wellbore in a landfill, the method comprising: The float in the pump chamber of the landfill pump is raised to the upper limit of the stroke so that the valve assembly is actuated to the discharge state via the control lever; With the valve assembly in the discharge state, compressed gas flow is allowed to enter the pump chamber from the pneumatic inlet channel of the landfill pump. The compressed gas drives the liquid in the pump chamber to flow downward and enter the distribution pipe through at least one port of the distribution pipe, then flows upward along the distribution pipe and flows out through the liquid outlet of the landfill pump. At the lower limit of the float's stroke, a lower stop is used along the control rod to stop the float's downward stroke. The float causes the control rod to actuate the valve assembly to a filled state, in which the flow of compressed gas to the pump chamber is cut off. The lower stop stops the float's downward stroke, forming an expansion chamber within the pump chamber, the expansion chamber having a first axial length between the lower limit of the stroke and the at least one port. By restricting the flow of compressed gas from the pump chamber through a throttling orifice located in the pneumatic outlet channel of the landfill pump, the compressed gas in the pump chamber continues to expand when the valve assembly is in the filled state, so that the landfill pump continues to output liquid when the valve assembly is in the filled state. Wherein, the first axial length is at least 20% of the second axial length of the pump chamber between the at least one port and the upper end of the pump chamber.

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