Piston pump and applications therefor

A device for elevating liquid through a well in a landfill or other geological site, comprising:

• a casing means for channeling liquid, said casing means having an upper end and a lower end;
• a lining means for lining said casing means, said lining means disposed within said casing means;
• a discharge means for removal of liquid from the casing means;
• a piston means for elevating liquid toward said discharge means, said piston means comprising:
• an actuating rod having an upper end and a lower end, and
• a piston valve unit disposed within the lining means and operatively connected to said actuating rod;
• a stationary valve unit disposed within said lining means;
• said stationary valve unit remaining in a substantially fixed position relative to the lining means during movement of the piston means;
• each of said valve units comprising
• a valve means for permitting liquid to flow through said valve unit toward the discharge means, and for preventing liquid from flowing through said valve unit away from said discharge means;
• wherein said piston valve unit prevents liquid communication around an outer periphery of said piston valve unit when said piston valve unit is disposed within said lining means, but permits such liquid communication when said piston valve unit is disposed within said casing means and above said lining means.

A method for elevating liquid through a well in a geological site, comprising:

• inserting into the geological site a casing means for channeling liquid, said casing means having an upper end and a lower end;
• inserting a stationary valve unit into the casing means;
• inserting into the casing means a removable piston means for elevating liquid, said piston means comprising:
• an actuating rod having an upper end and a lower end,
• and a piston valve unit operatively connected to said actuating rod;
• reciprocally raising and lowering the piston means to elevate liquid from below the surface of the geological site through the casing means toward the surface;
• wherein the geological site is a landfill, and the liquid is landfill leachate.

A device for elevating liquid through a well in a landfill or other geological site, comprising:

• a casing means for channeling liquid, said casing means having an upper end and a lower end;
• a discharge means for removal of liquid from the casing means;
• a removable piston means for elevating liquid toward said discharge means, said piston means comprising:
• an actuating rod having an upper end and a lower end, and
• a piston valve unit disposed within the casing means and operatively connected to said actuating rod;
• a removable stationary valve unit disposed within said casing means;
• said stationary valve unit remaining in a substantially fixed position relative to the casing means during movement of the piston means;
• engagement means for reversibly connecting the piston means to the stationary valve unit, said engagement means comprising a structure selected from a flange and a pin attached to one of said piston means and said stationary valve unit, wherein the other of said piston means and said stationary valve unit has a compatible slot or recess for receiving the flange or pin.

A device for elevating liquid through a well in a landfill or other geological site, comprising:

• a casing means for channeling liquid, said casing means having an upper end and a lower end;
• a discharge means for removal of liquid from the casing means;
• a piston means for elevating liquid toward said discharge means, said piston means comprising:
• a unitary actuating rod having an upper end and a lower end, and
• a piston valve unit disposed within the casing means and operatively connected to said actuating rod;
• a stationary valve unit disposed within said casing means;
• said stationary valve unit remaining in a substantially fixed position relative to the casing means during movement of the piston means.