Abstract: A spark ignited engine and method of its operation in which throttling losses are substantially eliminated has two intake manifolds operating at different charge air density levels. Suitable valves, upstream of conventional cylinder intake valves, are controlled to supply each of the cylinders with charge air from one or the other manifold. At high loads under operation of a controller all of the cylinders are supplied from the high density charge air manifold and at low loads all of the cylinders are supplied from the low density charge air manifold. At intermediate loads the controller supplies an appropriate number of cylinders from the high density manifold and the remaining cylinders from the low density manifold.

Abstract: Fugitive methane or natural gas vapors are recovered from a handling or delivery system and are blown through solid methane chips or a slush of solid and liquid methane. The solid methane melts and cools the vapors below the vaporization temperature to condense them. The condensed vapors and melted solid can be mixed with liquid methane for use therewith. The solid methane is produced by cooling liquid methane or natural gas in a liquid nitrogen heat exchanger or refrigerator. The liquid methane is solidified in a sheet on an endless belt, which breaks the sheet into pieces at a tail section.

Abstract: A high efficiency, high temperature radiant heating system utilizing regeneratively coupled combustors. The combustor/regenerator units each comprise a porous body with combustion supported in one layered zone and regeneration occurring in an adjacent layered zone in a subsequent cycle. Each combustor/regenerator unit cycles between combustion and regeneration operational modes and is gas flow coupled with a similar unit operating simultaneously in a mode opposite that of the former. Heat in the combustion products produced at one combustor/regenerator unit is received at the regenerator zone of the other coupled unit and vice versa.

Abstract: The heat exchange tube has a porous thermal shock resistant outer shell composed of a corrosion resistant ceramic material that may have a finned outer surface or a plain cylindrical outer surface. The outer shell contains an inner tube composed of a dense nonporous ceramic which is capable of containing high pressure gases, but which may not be as thermally shock resistant or corrosion resistant as the outer shell. The inner tube is formed of a dense ceramic material such as a highly dense silicon carbide or silicon nitride having at each end a like density insert. The end inserts provide sealing surfaces to contact other components in the heat exchanger such as identical ceramic tube assemblies to form a gas-type pressure seal. The inner tube can be fabricated by a deposition technique suh as a chemical or physical vapor deposition, and alternatively, can be made separately and press fitted into the outer shell or the outer shell can be cast or otherwise formed around the inner tube.

Abstract: An internally recirculating burner designed to operate at a low level of excess air without producing intolerable levels of particulate (smoke) and oxides of nitrogen using ambient or highly preheated atmospheric air as an oxidant. The burner operates with a flame front outside of the burner in the combustion chamber with recirculation of furnace gas being provided by the geometric configuration of the burner and the energy provided by the incoming combustion air. A nozzle means for controlling the combustion air flow is disclosed concentric with the burner center body. The nozzle is comprised of a fixed ceramic nozzle plate having annularly arranged distribution holes and a nozzle plus also preferably of ceramic supported to open and close the annular flow passage between the nozzle and the burner center body as well as the annular flow distribution holes.

Abstract: The heat exchange tube has a porous thermal shock resistant outer shell composed of a corrosion resistant ceramic material that may have a finned outer surface or a plain cylindrical outer surface. The outer shell contains an inner tube composed of a dense nonporous ceramic which is capable of containing high pressure gases, but which may not be as thermally shock resistant or corrosion resistant as the outer shell. The inner tube is formed of a dense ceramic material such as a highly dense silicon carbide or silicon nitride having at each end a like density insert. The end inserts provide sealing surfaces to contact other components in the heat exchanger such as identical ceramic tube assemblies to form a gas-type pressure seal. The inner tube can be fabricated by a deposition technique such as a chemical or physical vapor deposition, and alternatively, can be made separately and press fitted into the outer shell or the outer shell can be cast or otherwise formed around the inner tube.

Abstract: A primary combustion chamber is located above a secondary combustion chamber with a support grate between the two for supporting particulate solid waste fuel to be burned efficiently. Primary air is introduced to the primary combustion chamber with secondary air introduced below the grate into a combustion gas flow to cause complete burning in the secondary combustion chamber. A brick wall screen means of high temperature, corrosion-resistant brick forms the secondary combustion chamber to allow exhaust gaseous product to exit therethrough while screening out ash which can be removed from the combustion area. The gaseous product passed through the screen is then passed to a heat exchanger to utilize part of the heat produced for heating primary and secondary air used in the combustor. The exhaust gas from the heat exchanger can then be put to use in a boiler or other energy producing device.

Abstract: An energy conserving process furnace has a recuperator to utilize heat derived from exhaust gases in order to reduce fossil fuel consumption of the furnace. Elongated, enhanced surface ceramic heat exchanger tubes are used in the recuperator to recover heat energy from the exhaust gas. A preferred sealing arrangement is used between the metal and ceramic tubes to contain the combustion air. Heat is added by the recuperator to combustion air used in a fluid fuel burner. The ceramic tubes are provided with vibration protective mechanisms to prolong useful life under severe mechanical vibration encountered in some applications.In a method of operating a slot furnace, exhaust gas is exhausted from a side of the furnace through the slot or a passageway having an elongated horizontal cross section. In the preferred arrangement a second passage or air curtain passageway is positioned adjacent the first passageway to permit proper gas flow through a recuperator.

Abstract: A bellows arrangement for forming a gas leakage resistant pressure seal between ceramic heat exchange tubes has an elongated metallic bellows defining a central passageway with first and second ends. A metallic tube passes through the bellows and freely moves with respect to the second end of the bellows while defining a gas chamber between the tube and bellows. Axial expansion of the bellows under the influence of the internal pressure when such pressure is higher than the external pressure which may be the atmosphere acts to apply a force at the interface between the bellows assembly and the ceramic heat exchange tube which is proportional to the internal pressure of the heat exchange tube, thereby accommodating movement of the heat exchange tube and providing a pressure seal that is leak resistant.

Abstract: A slot furnace has a radiation resistant door which can easily be opened and closed as necessary during operation. The door is mounted on a pivot so that an end thereof covered with heat resistant insulation can be pivoted to open and close the slot when desired, to allow ease of feeding and removing materials from the furnace while preventing substantial radiational heat loss during normal operations.

Abstract: An energy conserving process furnace has a recuperator to utilize heat derived from exhaust gases in order to reduce fossil fuel consumption of the furnace. Elongated, enhanced surface ceramic heat exchanger tubes are used in the recuperator to recover heat energy from the exhaust gas. A preferred sealing arrangement is used between the metal and ceramic tubes to contain the combustion air. Heat is added by the recuperator to combustion air used in a fluid fuel burner.A recirculating burner has a flame front outside of the burner in the combustion chamber. The recirculating burner means acts to reduce the combustion air requirements and to provide a combustion zone low in oxygen so as to prevent scale formation and oxidation of metals being treated in the furnace area.

Abstract: An energy conserving process furnace has a recuperator to utilize heat derived from exhaust gases in order to reduce fossil fuel consumption of the furnace. Elongated, enhanced surface ceramic heat exchanger tubes are used in the recuperator to recover heat energy from the exhaust gas. A preferred sealing arrangement is used between the metal and ceramic tubes to contain the combustion air. Heat is added by the recuperator to combustion air used in a fluid fuel burner. The ceramic tubes are provided with vibration protective mechanisms to prolong useful life under severe mechanical vibration encountered in some applications.In a method of operating a slot furnace, exhaust gas is exhausted from a side of the furnace through the slot or a passageway having an elongated horizontal cross section. In the preferred arrangement a second passage or air curtain passageway is positioned adjacent the first passageway to permit proper gas flow through a recuperator.