Abstract: A tube disposed in the combustion chamber of a standing pilot type fuel-fired water heater is used to increase the overall efficiency of the water heater by improving the heat transfer from the pilot flame to the tank during standby periods by funneling the standing pilot flame upwardly through the tube in a manner concentrating the pilot flame heat against an underside portion of the bottom head of the water heater tank. To further increase water heater efficiency, the pilot burner is of a dual input type. Various pilot burner operational algorithm modes are disclosed for causing the pilot burner to operate at a high firing rate during main burner operation, and at a low firing rate during standby periods.

Abstract: A tube disposed in the combustion chamber of a standing pilot type fuel-fired water heater is used to increase the overall efficiency of the water heater by improving the heat transfer from the pilot flame to the tank during standby periods by funneling the standing pilot flame upwardly through the tube in a manner concentrating the pilot flame heat against an underside portion of the bottom head of the water heater tank. To further increase water heater efficiency, the pilot burner is of a dual input type. Various pilot burner operational algorithm modes are disclosed for causing the pilot burner to operate at a high firing rate during main burner operation, and at a low firing rate during standby periods.

Abstract: A process is provided for constructing a fluid impermeable subterranean barrier wall in a permeable earthen material at an earthen surface. The process is initiated by excavating an earthen pit in the permeable earthen material. A gelable slurry is prepared including unconsolidated solids, an aqueous solvent, a crosslinkable polymer, and a polymer crosslinking agent. The unconsolidated solids have a bulk component consisting of a soil or a clay. The unconsolidated solids can also include a number of additive agents which enhance the performance of the gelable slurry, such as density control agents, mixing agents, permeability reduction agents, filtration control agents and strength loss reduction agents. The gelable slurry is placed in the earthen pit and gelled to substantial maturity. The resulting gel binds the unconsolidated solids present in the earthen pit to convert the gelable slurry to a gelled continuum of consolidated solids, which forms the fluid impermeable barrier wall in the earthen pit.

Abstract: A non-crosslinking salt of a monovalent cation is added to a gelation solution comprising an acrylamide polymer and a redox crosslinking system to render the viscosity and uniformity of the resulting gel less sensitive to the concentrations of the gel components. The gel is used for conformance correction treatments of subterranean hydrocarbon-bearing formations to reduce the permeability of a high permeability zone adjacent a low permeability zone.

Abstract: A gelation system for reducing the permeability of a subterranean region is provided by sequentially injecting slugs of a polymer solution and a crosslinking agent solution capable of crosslinking the polymer. The viscosity of the crosslinking agent solution is adjusted to facilitate mixing of the slugs in the desired treatment region to a form gel therein and minimize premature gelation outside of the treatment region.