US3133212A - Electric generator - Google Patents

Description

mm REFERENCF SHRCH WM 3,1455%212 QLUll May 12, 1964 s. SZEKELY ELECTRIC GENERATOR Filed Dec. 30, 1959 United States Patent 3,133,212 ELECTRIC GENERATOR Steven Szekely, 645 Lelferts Ave., Brooklyn 3, N.Y., as-

signor of twenty-five percent to Louis M. Friedman and twenty-five percent to Karl F. Ross, both of New York, N.Y.

Filed Dec. 30, 1959, Ser. No. 862,828 4 Claims. (Cl. 3104) My present invention relates to a system for generating electric current.

It is an object of my invention to provide an improved system for the thermal generation of electric current.

It is another object of the invention to provide an electro-generating system obviating major mechanical losses and adapted to make use of existing high-temperature heat sources.

A more particular object of this invention is to provide means for improving the efficiency of an electric generator of the magnetohydrodynamic type.

A feature of my invention resides in the provision of an electric generating system, operating by a thermodynamic cycle, in which the heat content of a high-temperature fluid (preferably a vapor), rendered at least partially conductive by the presence of electrons produced externally thereof, is converted to kinetic energy whereby the conductive fluid may be passed at a relatively high velocity through a magnetic field to generate the electric current.

3,133,212 Patented May 12, 1964 heat content of the fluid and may be dispensed with should a closed thermodynamic cycle be undesirable. Thus, the invention may be utilized effectively for the generation of electric energy from a rocket or jet exhaust; the hot exhaust gases may be exposed to an electron cloud in order to increase the conductivity of the exhaust which is then passed between the electrodes of a generating chamber. After the negative charge is stripped from the fluid whose kinetic energy has been utilized to increase the velocity of the charge cloud, the waste fluid may be released since no recirculation will be necessary.

The bombardment of a vapor with charged particles (electrons) in the system of my invention converts it, in effect, into a plasma-like fluid at temperatures materially below thos'e 'usedfor the production of plasmas in conventional magnetohydrodynamic generating systems. The present system may, however, also be used in otherwise conventional magnetohydrodynamic systems to accelerate the formation of plasmas by thermally induced autoionization, and to increase the conductivities of plasmas originally containing substantially equal numbers of positively and negatively charged particles.

The above and other objects, features and advantages of my present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a somewhat schematic side-elevational view, partly in section, of a generating system according to According to another feature of the invention, the electhe invention; ei flnLatu g iyilmm-anmittemdisposewong-thk FIG. 2 is a cross-sectional view taken along line II-II w ath f the fluid. A thermionic emitter, heated to electron-emission temperature preferably by the high-temperature fluid prior to the release of its potential energy, may be conveniently utilized in the system. The negatively charged particles entrained by the fluid may be magnetically deflected onto a suitable collector to produce a potential difference between the latter and a counterelectrode between which there will thus pass an electric current. The conductive fluid may be caused to move within the transverse magnetic field at a considerably increased velocity as a result of the partial conversion of its heat content to kinetic energy.

Still another feature of the invention resides in t entrainment of thermionically emitted negatively charged particles by the vapor state of a fluid through a Venturi nozzle as the fluid is injected under pressure into a generating chamber, having a substantially lower pressure, wherein the fluid carrier and the entrained negative cloud move past one or more collector electrodes toward which the negatively charged particles are then directed by a magnetic deflecting field whose lines of force run substantially perpendicular to the fluid path.

According to a more specific feature of my preseh invention, a fluid of relatively high conductivity and, preferably, large collision cross-section (e.g. sodium or mercury) is heated by suitable means (a furnace or a nuclear reactor) and passed through a toroidal chamber whose inner wall is provided, on the outer surface thereof, with a thermionically emissive layer (e.g. a metal oxide), thereby raising the temperature of that layer to or above the point required for electron emission. The hot fluid is then passed through a Venturi nozzle opening into the generating chamber which is provided with return tubes conducting a portion of the fluid behind the Venturi nozzle whereby the fluid is recirculated to entrain the emitted electrons, at a relatively high velocity due to its rapid expansion at the nozzle, to the region of the collector electrode or electrodes. The fluid vapor is then con densed or compressed and recirculated to the heating station to complete the thermodynamic cycle. The liquefaction stage serves only to remove the residual, unusable originating at the high-temperature source 10 and adapted to conduct a hot fluid, preferably a vapor under pressure, through a toroidal shell 22 and thence via a pipe 23 and a Venturi injector nozzle 24 through the center of the torus into a generating chamber 25. The toroidal shell 22 is surrounded by a low-pressure chamber 26 provided with apertures 27 which communicate, via return tubes 28 terminating in apertures 29, with the interior of generating chamber 25 at a location downstream from the injector nozzle 24. The outer s urface of inner wall 30 of shell 22 is provided with a layer 31 of a thermionic electron emitter, such as lanthanum borohydride, metal oxides and the like, adapated to be raised to the emission temperature by the heated fluid traversing shell 22. The mouth 32 of injector 24 opens into the generating chamber 25 at a point just beyond the emitter ring to prevent chilling of layer 31 by the expansion-cooled fluid at the injector mouth. The generating chamber 25 houses a pair of collector electrodes 33, 34 and a pair of counter-electrodes 35, 36 (see also FIG. 3), opposite the collector electrodes, between the poles 37 and 38 of a constantflux magnet 40.

Generating chamber 25 is provided with an outlet pipe 41 forming a fluid path between the latter and the lowtemperature sink 50 which, advantageously, is a condenser having an inlet 42 and an outlet 43 for a circulating coolant. Condenser 50 is fitted with a pipe 44 connecting the latter with the fluid-circulating pump 51 which discharges via a pipe 45 into the high tempera ture source 10. The path of the recirculated fluid may, as shown in dot-dash lines, include a regenerative heating stage 60 wherein a portion of the residual heat content of the fluid streaming toward the condenser 50 may be utilized to preheat the condensed fluid before the latter is admitted to the main heater l0. Condenser 50 serves to maintain a partial vacuum in chamber 25.

In operation, a preferably conductive fluid, such as liquid sodium or mercury, is heated within the high-temperature source to temperatures in excess of the temperature required for thermionic emission from layer 31. The resulting vapor is then passed through the toroidal shell 22 via pipe 21 so that the layer 31 commences thermionic emission. The emitted electrons tend to accumulate and form a negatively charged electron cloud in the vicinity of layer 31, this cloud mingling with fluid particles drawn off from the vapor stream at apertures 29 and reintroduced thereto via return tubes 28. This portion of the fluid enters reduced-pressure chamber 26 and is then siphoned through the central opening of the shell 22 into the chamber 25, entraining the negatively charged particles. As the fluid passes through the central opening, its negatively charged particles are swept into the generating chamber 25. The carrier fluid travels with a relatively rapid motion toward the electrode pairs 33, 35 and 34, 36 by reason of the high velocity of the vapor stream emanating from the mouth 32 of Venturi nozzle 24. The charged particles are then deflected toward collector plates 33 and 34 by the transverse magnetic field created by the poles 3'7 and 38. The fluid, stripped of its entrained negative charge, is then condensed in the heat sink 50 and recirculated to the hightemperature source 10 by pump 51, to recommence the thermodynamic cycle.

In FIG. 3 I show the collector electrodes 33, 34 connected in parallel, for maximum current, to a load 47 which is connected to the potential of emitter 31 (i.e. ground) through the slider 48 of a potentiometer 4Q. Counter-electrodes 35, 36 are connected in parallel to the other terminal of the resistor 49. It will thus be apparent that the emitter 31 will be at a potential intermediate that of electrodes 33, 34 and 35, 36, and that the current flowing through the load 47 will depend on the rate of electron collection at electrodes 33, 34. The current flow will be a function of the emission rate and of the vapor velocity. The positive potential induced on electrodes 35, 36 maintains the net charge at the center of the magnetic deflection field substantially at or near zero to prevent the accumulation of a negative space charge which would oppose the entry of further electrons into this region.

Owing to the non-linear deflection of the charged particles by the magnetic field, it will be seen that one collector (e.g. electrode 33) may be positioned to receive a greater negative charge than an adjacent electrode (e.g. electrode 34). The potential difference between electrode 33 and ground will thus be greater than that between electrode 34 and ground when the two are disconnected. A plurality of such electrodes, spaced along the fluid path, may therefore be provided to tap the generator at different voltages and/or power outputs. It is also possible to utilize the potential drop between these electrodes to energize a load, e.g., as indicated at 47 in FIG. 3.

For maximum utilization of the heat content of the fluid, the latter may be initially heated to a temperature such that, on leaving the generating stage, it has a temperature in the vicinity of its boiling point.

The generating system illustrated and described admits of many variations and modifications readily apparent to persons skilled in the art and intended to be included within the spirit and scope of my invention, except as further limited by the appended claims.

I claim:

1. In an electric-current generator, in combination, a generally toroidal shell having an inner peripheral wall of thermally conductive material forming a central chamber, said wall being provided with an electron-emissive layer in said chamber, conduit means having an incoming branch and an outgoing branch opening into the interior of said shell, said conduit means further including a duct forming an extension of said chamber, said outgoing branch terminating in a nozzle extending into said chamber along the toroidal axis of said shell in spaced relationship with said layer, a source of gaseous fluid connected to said conduit means, heating means adjacent said conduit means for bringing said fluid to an elevated temperature, circulating means for passing said fluid at said elevated temperature through said incoming branch, said shell, said outgoing branch, said nozzle and part of said chamber into said duct, recirculating means forming a return path for part of said fluid from a downstream location in said duct to an upstream location at the end of said chamber remote from said duct into the space between said layer and said nozzle, said elevated temperature being high enough to activate said layer for injecting electrons into the recirculated part of the fluid within said space, and collector means for said electrons positioned in said duct.

2. In an electric-current generator, in combination, a generally toroidal shell having a substantially frustoconical inner peripheral wall of thermally conductive material forming a central chamber, said wall being provided with an electron-emissive layer in said chamber, conduit means having an incoming branch and an outgoing branch opening into the interior of said shell, said conduit means further including a duct forming an extension of said chamber beyond the narrower end thereof, said outgoing branch terminating in a nozzle extending into said chamber in the direction of convergence thereof and along the toroidal axis of said shell in spaced relationship with said layer, a source of gaseous fluid connected to said conduit means, heating means adjacent said conduit means for bringing said fluid to an elevated temperature, circulating means for passing said fluid at said elevated temperature through said incoming branch, said shell, said outgoing branch, said nozzle and part of said chamber into said duct, recirculating means forming a return path for part of said fluid from a downstream location in said duct to an upstream location at the wider end of said chamber into the space between said layer and said nozzle, said elevated temperature being high enough to activate said layer for injecting electrons into the recirculated part of the fluid within said space, and collector means for said electrons positioned in said duct.

3. In an electric-current generator, in combination, a generally toroidal shell having an inner peripheral wall of thermally conductive material forming a central chamber, said wall being provided with an electron-emissive layer in said chamber, conduit means having an incoming branch and an outgoing branch opening into the interior of said shell, said conduit means further including a duct forming an extension of said chamber, said outgoing branch terminating in a nozzle extending into said chamber along the toroidal axis of said shell in spaced relationship with said layer, a source of gaseous fluid connected to said conduit means, heating means adjacent said conduit means for bringing said fluid to an elevated temperature, circulating means for passing said fluid at said elevated temperature through said incoming branch, said shell, said outgoing branch, said nozzle and part of said chamber into said duct, said elevated temperature being high enough to activate said layer for injecting electrons into the fluid passing through said space, and collector means for said electrons positioned in said duct.

4. In an electric-current generator, in combination, a generally toroidal shell having a substantially frustoconical inner peripheral wall of thermally conductive material forming a central chamber, said wall being provided with an electron-emissive layer in said chamber, conduit means having an incoming branch and an outgoing branch opening into the interior of said shell, said conduit means further including a duct forming an extension of said chamber beyond the narrower end thereof, said outgoing branch terminating in a nozzle extending into said chamber in the direction of convergence thereof and along the toroidal axis of said shell in spaced relationship with said layer, a source of gaseous fluid connected to said conduit means, heating means adjacent said conduit means for bringing said fluid to an elevated temperature, circulating means for passing said fluid at said elevated temperature through said incoming branch, said shell, said outgoing branch, said nozzle and part of said chamber into said duct, said References Cited in the file of this patent UNITED STATES PATENTS Rudenberg June 18, 1929 Johnstone Dec. 2, 1958

Claims (1)

1. IN AN ELECTRIC-CURRENT GENERATOR, IN COMBINATION, A GENERALLY TOROIDAL SHELL HAVING AN INNER PERIPHERAL WALL OF THERMALLY CONDUCTIVE MATERIAL FORMING A CENTRAL CHAMBER, SAID WALL BEING PROVIDED WITH AN ELECTRON-EMISSIVE LAYER IN SAID CHAMBER, CONDUIT MEANS HAVING AN INCOMING BRANCH AND AN OUTGOING BRANCH OPENING INTO THE INTERIOR OF SAID SHELL, SAID CONDUIT MEANS FURTHER INCLUDING A DUCT FORMING AN EXTENSION OF SAID CHAMBER, SAID OUTGOING BRANCH TERMINATING IN A NOZZLE EXTENDING INTO SAID CHAMBER ALONG THE TOROIDAL AXIS OF SAID SHELL IN SPACED RELATIONSHIP WITH SAID LAYER, A SOURCE OF GASEOUS FLUID CONNECTED TO SAID CONDUIT MEANS, HEATING MEANS ADJACENT SAID CONDUIT MEANS FOR BRINGING SAID FLUID TO AN ELEVATED TEMPERATURE, CIRCULATING MEANS FOR PASSING SAID FLUID AT SAID ELEVATED TEMPERATURE THROUGH SAID INCOMING BRANCH, SAID SHELL, SAID OUTGOING BRANCH, SAID NOZZLE AND PART OF SAID CHAMBER INTO SAID DUCT, RECIRCULATING MEANS FORMING A RETURN PATH FOR PART OF SAID FLUID FROM A DOWNSTREAM LOCATION IN SAID DUCT TO AN UPSTREAM LOCATION AT THE END OF SAID CHAMBER REMOTE FROM SAID DUCT INTO THE SPACE BETWEEN SAID LAYER AND SAID NOZZLE, SAID ELEVATED TEMPERATURE BEING HIGH ENOUGH TO ACTIVATE SAID LAYER FOR INJECTING ELECTRONS INTO THE RECIRCULATED PART OF THE FLUID WITHIN SAID SPACE, AND COLLECTOR MEANS FOR SAID ELECTRONS POSITIONED IN SAID DUCT.

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