Abstract: A flame retention head for a nozzle block assembly of a waste oil-burning system, such as a furnace, having a combustion zone within which oil is burned in the presence of air utilizes a platen-like body of substantially circular form having a central opening through which an atomizing nozzle is positioned for directing air and oil into the combustion zone for burning. The central opening has a diameter of no less than about 1.3 inches, and the platen-like body including a plurality of radially-extending vanes formed therein wherein each vane forms with the remainder of the platen-like body a gap which is joined to and extends radially-outwardly of the central opening. Each gap formed by a vane has a width which is no less than about 0.07 inches. Associated with the nozzle block assembly is at least one air vane for balancing the air flow moving past the flame retention head and toward the combustion zone.

Abstract: A fuel control and preheating module for use with an oil-burning furnace including a fuel line providing a passageway section through which oil is routed from a reservoir to the furnace for burning includes an electrically-powered positive temperature coefficient (PTC) heating element mounted in heat transfer relationship with oil contained with the passageway section. During the operation of the PTC element, the PTC element heats the oil contained within the passageway section to a preselected temperature and maintains the oil contained within the passageway section at the preselected temperature. Also associated with the module is a movable diaphragm and shutoff plate which is responsive to the internal pressure changes in the air passageway of the furnace upon shutdown and start-up of the furnace to withdraw oil from and shut off delivery of oil to the nozzle upon furnace shutdown and to push oil toward the nozzle upon start-up of the furnace.

Abstract: An oil-burning furnace including a combustion zone and a nozzle block assembly through which oil and pressurized air are introduced into the combustion zone utilizes an oil pump of trochoidal design for delivering oil to the combustion zone at a metered rate and a purge control for withdrawing oil from the nozzle block assembly upon shut down of the furnace operation. The flow rate at which the oil pump delivers the oil to the nozzle block assembly is relatively constant regardless of the weight or viscosity of the oil burned by the furnace, and the purge control cooperates with an air compressor used for delivering air, under pressure, to the nozzle block assembly and includes an expandable zone for extracting oil from the nozzle block assembly upon a de-energizing of the air compressor.