A pressing-pulling device includes: a pressing-pulling bracket, wherein slotting oil cylinders are symmetrically and vertically mounted on the pressing-pulling bracket, and a piston rod of each of the slotting oil cylinders faces downwardly; a bottom end of the piston rod is connected to a connecting plate, and a through-hole is provided in a middle of the connecting plate; a continuous lifting mechanism is installed in a middle of the pressing-pulling bracket, and a slotting rod is vertically inserted into the continuous lifting mechanism; a lifting ring is installed at a top end of the slotting rod; a bottom end of the slotting rod extends downwardly through the through-hole to connect to a slotting cutter; a locking device is fixed on the connecting plate near the through-hole for fixing the slotting rod.

A method for use by a system coupled to at least one sensor and at least one flow control mechanism of a gas extraction system, the system comprising at least one controller and configured for use in connection with a landfill gas extraction process for extraction of landfill gas from a landfill via the gas extraction system, the method comprising: using the at least one controller to perform: obtaining, based on at least one measurement made by the at least one sensor, at least one current value indicative of a selected characteristic of the landfill gas extraction process, determining, at discrete time intervals, whether the at least one current value satisfies at least one compliance criterion for the selected characteristic, and when it is determined that the at least one current value does not satisfy the at least one compliance criterion for the selected characteristic, performing a corrective action.

A multi-function valve is disclosed. The multi-function valve including a housing having an internal bore therein; a spool valve positioned in the internal bore, the spool valve configured to seal and direct a flow of compressed air and exhaust; and a spring operably connected to the spool valve, the spring biasing the spool valve in a normally open exhausting position.

Devices and techniques related to landfill gas extraction are disclosed. A technique for controlling extraction of landfill gas from a landfill through a gas extraction system is described. The method may include measuring a plurality of values indicating conditions associated with the landfill; computing, based at least in part on the plurality of values and on a model of the landfill, a predicted future state of the landfill; determining, based at least in part on the predicted future state of the landfill, one or more control parameters for one or more respective control devices configured to control operation of the gas extraction system; applying the one or more control parameters to the one or more respective control, and with the one or more control devices, controlling extraction of the landfill gas from the landfill based, at least in part, on the one or more respective control parameters.

A control system for controlling extraction of landfill gas from a landfill via a gas extraction system comprising well piping, the landfill gas having a first temperature when extracted, the control system comprising: a gas composition chamber coupled to the well piping and comprising at least one sensor configured to measure one or more characteristics of a landfill gas sample in the gas composition chamber; a temperature control mechanism configured to heat the landfill gas sample in the gas composition chamber to a second temperature at least a threshold amount greater than the first temperature; and a controller configured to control the at least one sensor to measure the one or more characteristics of the landfill gas sample in the gas composition chamber when a temperature of the landfill gas sample in the gas composition chamber is at least the threshold amount greater than the first temperature.

Systems and methods are disclosed for landfill systems, comprising waste, a geosynthetic product, and a layer of foam glass aggregates interposed between the waste and the geosynthetic product.

A system and method for monitoring or controlling an aerobic landfill bioreactor having a plurality of zones each including at least one well head. The system comprises: a gas extraction blower, a plurality of temperature sensors disposed in the well heads, an ex-situ relative humidity detector, an ex-situ gas constituent detector, an air injection system, a liquid injection system, and a controller. Landfill gas is extracted by the blower and it's temperature, relative humidity, and gas constituents are measured. The system further comprises a system of headers, isolation valves, and flow control valves which serve to isolate zones for measurement and/or air and liquid injection as well as control the flow of either the landfill gas extraction or liquid and air injection. The method involves measuring: temperature, relative humidity, and gas constituents of the extracted landfill gas. Advantageously, the ex-site placement of the sensors and detectors ensure that measurements are representative of the aerobic bioreactor operating parameters. The air and liquid injection systems are adjusted, based on the measured temperature, relative humidity, and gas constituents to optimize the operation of the aerobic landfill bioreactor.

A well head cover and assembly is disclosed. The well head cover includes a top discharge section; a bottom engagement section; and a middle section interconnecting the top and bottom sections. The top section includes a sleeve of a predetermined length to prevent the well head cover from tilting when installed on a conduit.

A control system for controlling extraction of landfill gas, comprising: at least one sensor configured to measure one or more characteristics of landfill gas; at least one flow control mechanism disposed in well piping and configured to control flow of the landfill gas through the well piping; and at least one processor configured to: obtain a measured concentration of a first gas in landfill gas; determine whether the measured concentration of the first gas is either less than a first threshold concentration or greater than a second threshold concentration; when it is determined that the measured concentration is less than the first threshold concentration, control the at least one flow control mechanism to reduce flow rate of landfill gas; and when it is determined that the concentration is greater than the second threshold concentration, control the at least one flow control mechanism to increase the flow rate of landfill gas.

Devices and techniques related to landfill gas extraction are disclosed. A technique for controlling extraction of landfill gas from a landfill through a gas extraction system is described. The method may include measuring a plurality of values indicating conditions associated with the landfill; computing, based at least in part on the plurality of values and on a model of the landfill, a predicted future state of the landfill; determining, based at least in part on the predicted future state of the landfill, one or more control parameters for one or more respective control devices configured to control operation of the gas extraction system; applying the one or more control parameters to the one or more respective control, and with the one or more control devices, controlling extraction of the landfill gas from the landfill based, at least in part, on the one or more respective control parameters.