Abstract: An improved heat exchanger with two counter-flow passages, a first passage through a round, central tube and a second passage which is annular to the first flow passage. The fluids enter the passages tangentially or past swirl-generating foils at the tube entrance such that fluids are driven to flow in a vortex. The central tube contains a swirling flow of cooler fluid. The annular passage contains warmer swirling fluid flowing in the opposite axial direction from the cooler fluid. The purpose of the heat exchanger is to heat the cooler swirling fluid as it flows through the central tube or to cool the warmer swirling fluid as it flows through the annulus. In some embodiments, fins or other projections on the wetted surfaces of the tubes will be oriented to sustain vortex flow throughout the passages. In some embodiments the outlets may be tangential to recover the some of the kinetic energy of the vortex flow. The tangential outlets may be enlarged for still greater kinetic energy recovery.

Abstract: The external combustion hot air power system comprises a compressor, a recuperator, a heated mult-process expander, a surrounding combustion chamber and necessary fuel system, controls, fluid flow passages, mechanical connections and structure. The multiprocess expander provides for isobaric and isothermal expansions. Air is compressed and then heated by combustion products in a recuperator heat exchanger. This hot compressed air is further heated and expanded at approximately constant pressure in the isobaric expander to generate power. Additional power is generated downstream by isothermal expansion. Hot expanded air flows from the expander into the surrounding combustion chamber to support combustion. Isobaric expansion must be heated by the hottest portion of the combustion chamber to increase the temperature of the expanding gas. Combustion products flow from the combustion chamber and through the hot side of the (recuperator) heat exchanger to regeneratively heat previously compressed air.

Abstract: A lawn mower is powered by a quiet external combustion engine which is based on an Ericcson cycle which has been modified for more efficient combustion and higher temperature from the regenerative heat exchanger. Air is compressed in a compressor, then regeneratively heated in a heat exchanger by combustion exhaust prior to being expanded in a heated expander to generate power. The heated expander is in intimate thermal contact with the combustion chamber wherein combustion is efficiently supported by hot expanded air from the heated expander. The lawn mower includes a starter and conventional means for control, support and locomation.

Abstract: The purpose of regenerative heat exchangers is to transfer the heat from one step or process of a cycle or system to an earlier step or process in the cycle or system such that the transferred heat is usefully absorbed rather than being discarded. The gas being heated is moved in a counter flow relative to the hotter fluid while being trapped between moving partitions (vanes) such that the gas so trapped is heated with a fixed volume with an increase in pressure as well as temperature. In some embodiments, the hotter as well as the cooler fluid is moved while trapped between moving partitions (vanes) so, as the cooler fluid being heated is thermally pressurized, the hotter fluid being cooled with a fixed volume is thermally pressurized. Materials and design details are selected to enhance the heat transfer between the two streams.

Abstract: The four processes of a reverse Stirling heat pump cycle; isothehermal compression with the heat of compression being transmitted to a constant, relatively high temperature sink, regenerative cooling, isothermal expansion with heat flow from a cooler, constant temperature source followed by regenerative heating from the heat derived from the previously compressed gas are all performed with constant rather than intermittent flow. A constant flow, constant volume counter-flow heat exchanger, placed between the compressor and expander, rather than an alternately heated and cooled heat storage matrix, provides for the steady flow regenerative heat transfer as required for a steady reverse Stirling cycle heat pump. This invention therefore provides for increased heat pump rate per unit volume.

Abstract: This is a system for continuously cleaning warm-air furnace air filters by the reverse flow of air from the downstream, interior side of a portion of the filter to the upstream, exterior side of the filter which is rotating such that every portion of said filter is driven past the inlet of plenum or plenums at which locations reverse pressure generates reverse air flow to dislodge the dust and, thereby, clean and filter and to then drive the airborne duct into a fluid conduit which directs the collected dust into a combustion chamber, or into the exhaust vent pipe, or a dust receptacle. This assures a constantly clean filter, full air flow, and efficient heat transfer from heat exchanger into the occupied space requiring heat.

Abstract: An air conditioning system with a common refrigerant supply, an engine-driven compressor circuit and a thermal compression circuit in parallel with the compressor circuit, a high efficiency compact thermal compressor which is either an ejector or a double vortex chamber flow inducer and a new control system which saves energy by unloading the mechanical compressor when thermal compression is fully operative. The hybrid system includes a check valve which prevents refrigerant flow from the compressor through the thermally powered compressor. Timers start the refrigerant pump of thermal compression circuit. Pressure switches sense operating pressure of the refrigerant. A refrigerant pump and a heat exchanger vapor generator generate high pressure refrigerant vapor which drives the thermal compressor. Refrigerant pump starts after initial cooling of passenger compartment is achieved by mechanical compressor circuit.

Abstract: A pin terminal for reducing the insertion force required to engage a connector with a mating contact terminal. The pin comprises a generally quadrilateral configured conducting member having one end formed with opposite curvilinear surfaces of different radii to generate a sequential deflection on blades of the contact terminal blades as the pin member is inserted into the contact terminal.