Landfill gas extraction control system throttle

Patent metadata

Field	Value
Publication number	US-11673171-B2
Application number	US-202017083970-A
Country	US
Kind code	B2
Filing date	Oct 29, 2020
Priority date	Jul 13, 2018
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

A system for extracting landfill gas from a landfill is provided. According to some embodiments, a control system for landfill gas extraction is provided. The control system uses a throttle to control flow of landfill gas extracted from the landfill. The throttle is actuated in use to vary the flow of gas between a well and a gas collection system, in accordance with a control algorithm that adjusts flow as a parameter in controlling gas extraction. The throttle is configured to ensure that there is at least some flow of landfill gas from the landfill to a gas output throughout operation. The extraction system provides an efficient system for landfill gas extraction, while mitigating a risk of creating undesired or unpleasant conditions and/or of violating regulations during operation.

First claim

What is claimed is:

1. A control system for controlling extraction of landfill gas from a landfill via a gas extraction system, the gas extraction system comprising well piping for coupling at least one well to a gas output, the control system comprising:
a throttle disposed in the well piping and comprising a movable member configured to restrict flow of landfill gas through an area of the well piping, wherein the movable member has a position of maximum closure at which the movable member provides a maximum amount of restriction to the flow of landfill gas permitted by the control system and which blocks less than a full area of an aperture of the well piping through which landfill gas flows so that at least some landfill gas can flow past the throttle with the movable member at the position of maximum closure within the throttle; and
a controller configured to control a position of the movable member to control the flow of landfill gas through the area of the well piping,
wherein the controller is programmed to prevent the throttle from blocking all flow of landfill gas through the area of well piping by limiting control signals sent to the throttle controlling motion of the movable member thereby precluding motion of the movable member beyond the position of maximum closure.

2. The control system of claim 1 , wherein the movable member comprises a plate configured to restrict the flow of landfill gas.

3. The control system of claim 2 , wherein controlling the position of the movable member comprises rotating the plate.

4. The control system of claim 2 , wherein controlling the position of the movable member comprises sliding the plate along a plane intersecting the flow of landfill gas.

5. The control system of claim 1 , wherein the movable member comprises a ball configured to restrict the flow of landfill gas.

6. The control system of claim 1 , wherein the throttle is configured to maintain a difference in pressure between upstream and downstream of the throttle greater than 0 mbar.

7. The control system of claim 1 , wherein the flow of landfill gas past the throttle when the movable member is at the position of maximum closure is at least 0.1 cubic feet per minute.

8. The control system of claim 1 , wherein the throttle comprises a motor configured to adjust a variable portion of the aperture through which the landfill gas flows.

9. The control system of claim 1 , wherein the throttle is configured to provide control of the flow of landfill gas on a continuous scale.

10. The control system of claim 1 , further comprising a flow measurement device configured to obtain a measurement of flow rate of landfill gas past the throttle, wherein the controller is configured to control the position of the movable member based at least on the obtained measurement of flow rate.

11. The control system of claim 1 , further comprising:
a pressure sensor configured to obtain a measurement of pressure upstream of the throttle;
wherein the controller is configured to control the position of the movable member based at least on the obtained measurement of the pressure upstream of the throttle.

Assignees

• Loci Controls Inc

Inventors

• Hale Mike
• Hale Keith
• Sims Melinda

Classifications

• Y02W30/30

  Landfill technologies aiming to mitigate methane emissions · CPC title

• E21B34/00

  Valve arrangements for boreholes or wells · CPC title

• B09B1/006 Primary

  Shafts or wells in waste dumps · CPC title

• E21B43/12 Primary

  Methods or apparatus for controlling the flow of the obtained fluid to or in wells (E21B43/25 takes precedence; valve arrangements E21B34/00) · CPC title

• Y02E50/30

  Fuel from waste, e.g. synthetic alcohol or diesel · CPC title