Methods and apparatus for triggering exothermic reactions using AC or DC electromagnetics

Abstract

Methods and apparatus are disclosed for generating an electromagnetic field inside a reactor to trigger an exothermic reaction. The design and implementation of the electromagnetics are based on the requirements of a particular exothermic reaction or reactor. For example, the triggering mechanism of a particular exothermic reaction or reactor may require a magnetic field with a specific magnitude, polarity, and/or orientation.

Claims

1. A method for inducing a magnetic field in an exothermic reactor to trigger an exothermic reaction, the exothermic reactor comprising a vessel and one or more reaction materials, the reactor maintaining a pressure and a temperature and being surrounded by one or more coils, the method comprising: supplying a current to the one or more coils, wherein the strength of the current is determined based on a desired characteristic of the magnetic field; and switching off the current after a first time period; wherein the desired characteristic of the magnetic field and the first time period are determined to trigger the exothermic reaction and wherein the desired characteristic of the magnetic field and the first time period are dependent on the type of the exothermic reactor.

2. The method of claim 1, wherein the desired characteristic of the magnetic field is a desired strength of the magnetic field or a desired polarity of the magnetic field.

3. The method of claim 2, wherein, when the current is supplied to the one or more coils, the strength of the magnetic field increases until the current is switched off, and wherein the first time period is determined based on the desired strength of the magnetic field and the current.

4. The method of claim 2, wherein, when the current is supplied to the one or more coils, the strength of the magnetic field reaches the maximum when the current reaches the maximum before the current is switched off, and wherein the first time period is determined based on the desired strength of the magnetic field and the current.

5. The method of claim 1, further comprising supplying the current to the one or more coils after a second time period.

6. The method of claim 5, wherein the direction of the current is reversed.

7. The method of claim 5, wherein the current is turned on and off periodically with a predetermined frequency for triggering the exothermic reaction.

8. The method of claim 6, wherein the frequency at which the direction of the current is reversed is determined for triggering the exothermic reaction.

9. The method of claim 1, wherein a first coil of the one or more coils is parallel to a second coil of the one or more coils, and wherein the magnetic field generated by the first coil is aligned with the magnetic field generated by the second coil.

10. The method of claim 1, wherein a first coil of the one or more coils is perpendicular to a second coil of the one or more coils, and wherein a current running through the first coil and a current running through the second coil are turned on and off alternately.

11. The method of claim 10, wherein the current in the first coil and the current in the second coil are phase locked.

12. The method of claim 1, wherein the desired characteristic of the magnetic field and the first time period further depend on one or more of the following factors: the one or more reaction materials, the temperature, the pressure, a substrate used for holding the one or more reaction materials, the shape of the exothermic reactor, and the size of the exothermic reaction.

13. An apparatus for inducing a magnetic field in an exothermic reactor to trigger an exothermic reaction, the exothermic reactor comprising a vessel, one or more reaction materials, the exothermic reactor maintaining a temperature and a pressure, said apparatus comprising: one or more coils positioned such that the one or more coils surround of the exothermic reactor; one or more power supplies for supplying one or more currents to the one or more coils; wherein the one or more power supplies are configured to: supply the one or more currents to the one or more coils, wherein the strength of each of the one or more currents is determined based on a desired characteristic of the magnetic field; and switch off the one or more currents after a first time period; wherein the desired characteristic of the magnetic field and the first time period are determined to trigger the exothermic reaction and wherein the desired characteristic of the magnetic field and the first time period are dependent on the type of the exothermic reactor.

14. The apparatus of claim 13, wherein the desired characteristic of the magnetic field is a desired strength of the magnetic field or a desired polarity of the magnetic field.

15. The apparatus of claim 14, wherein, when the current is supplied to the one or more coils, the strength of the magnetic field increases until the current is switched off, and wherein the first time period is determined based on the desired strength of the magnetic field and the current.

16. The apparatus of claim 14, wherein, when the current is supplied to the one or more coils, the strength of the magnetic field reaches the maximum when the current reaches the maximum before the current is switched off, and wherein the first time period is determined based on the desired strength of the magnetic field and the current.

17. The apparatus of claim 13, further comprising supplying the current to the one or more coils after a second time period.

18. The apparatus of claim 17, wherein the direction of the current is reversed.

19. The apparatus of claim 17, wherein the current is turned on and off periodically with a predetermined frequency for triggering the exothermic reaction.

20. The apparatus of claim 18, wherein the frequency at which the direction of the current is reversed is determined for triggering the exothermic reaction.

21. The apparatus of claim 13, wherein a first coil of the one or more coils is parallel to a second coil of the one or more coils, and wherein the magnetic field generated by the first coil is aligned with the magnetic field generated by the second coil.

22. The apparatus of claim 13, wherein a first coil of the one or more coils is perpendicular to a second coil of the one or more coils, and wherein a current running through the first coil and a current running through the second coil are turned on and off alternately.

23. The apparatus of claim 22, wherein the current running through the first coil and the current running through the second coil are phase locked.

24. The apparatus of claim 14, wherein the desired characteristic of the magnetic field and the first time period further depends on one or more of the following factors: the one or more reaction materials, the temperature, the pressure, a substrate used for holding the one or more reaction materials, the shape of the exothermic reactor, and the size of the exothermic reaction.

Description

BRIEF DESCRIPTION OF FIGURES

(1) FIG. 1 illustrates an exemplary power supply circuit configured to generate electromagnetic fields for triggering an exothermic reaction.

(2) FIGS. 2A and 2B illustrate an exemplary RL circuit and a current profile generated by the RL circuit.

(3) FIGS. 3A-5 illustrate exemplary current profiles generated by RL circuits.

(4) FIGS. 6A-6D illustrate different configurations of one or more electromagnetic circuits placed around a reactor.

(5) FIGS. 7A-7C illustrate examples of AC currents supplied to the electromagnetic circuits.

DETAILED DESCRIPTION

(6) In referring to FIG. 1, a block diagram illustrating an exemplary electric circuit 100 that comprises a controller 102, an H-Bridge circuit 104, a coil 106, an optional resistor Rsense 108 and a power supply 110. The circuit 100 is configured to generate magnetic fields of desired magnitudes and/or polarities by controlling the current that runs through the coil 106. In some embodiments, the coil 106 is a piece of metal wire with inductance L and resistance R. The H-Bridge Circuit 104 is configured to apply a reversible and variable voltage across the coil to generate variable currents of reversible directions. The controller 102 controls the H-Bridge Circuit 104. The controller 102 can be configured or programmed to enable the H-Bridge Circuit 104 to apply suitable voltages over the coil 106. The voltage over the coil 106 induces a current across the coil 106. The current generates a magnetic field in the space surrounding the coil.

(7) It is known in previous studies that a magnetic field of a suitable strength and polarity can trigger certain types of exothermic reactions. However, those studies are preliminary and do not provide sufficient details on the circuit used to generate the magnetic field and on the exact configuration of the magnetic field that can trigger the exothermic reactions. The present disclosure teaches methods and apparatus that can be utilized to generate a suitable magnetic field, of which the magnitude and polarity inside the reactor is designed to trigger an exothermic reaction. Depending on the type of the exothermic reactions or reactors, the characteristics of the triggering magnetic field may differ and the current supplied to the coil 106 will vary accordingly. For example, the following factors may be taken into consideration in designing a magnetic field as triggering mechanism: the reaction materials used in the reaction, whether they are ferromagnetic, for instance, the temperature, the pressure, a substrate used for holding the one or more reaction materials, the shape of the exothermic reactor, and the size of the exothermic reaction.

(8) FIG. 2A illustrates a simplified circuit representation of the coil 106 and FIG. 2B depicts an exemplary current induced in the coil 106 by the circuit 100. In FIG. 2A, the coil 106 is represented by an ideal inductor 202 of inductance L and an ideal resistor 204 of resistance R. The voltage applied across the coil 106 is represented by the power source 206 of voltage V. The current in the coil 106 as a function of time is depicted in FIG. 2B.

(9) $\tau =\frac{L}{R}$
is a time scale that measures the rate at which the current in the coil 106 increases. When the voltage V is applied to the coil 106, the current ramps up and quickly reaches the maximum value

(10) $\frac{V}{R}$
within a time period of 3τ-5τ. Parameter τ sets the limit on how fast the current induced in the coil 106 can change in response to the applied voltage V.

(11) FIG. 3A illustrates the current, i, induced in the coil 106 as a function of time in response to the voltage V applied across the coil 106 as shown in FIG. 3b. The voltage V is switched on and off periodically. It is switched on for a time period of t.sub.1 and then switched off for a time period of t.sub.2, . . . , and switched on for a time period of t.sub.2i−1 and switched off for a time period of t.sub.2i+1. The current induced in the coil 106 in response to the applied voltage V is shown in FIG. 3A. The current ramps up and drops down in response to the switching on and off of the voltage. Because the voltage is switched off before 5τ, the voltage is switched off before the current could reach the maximum value

(12) $\frac{V}{R}.$
During t.sub.2, the current drops down to zero more precipitously.

(13) FIG. 4 illustrates another variable current as a function of time. In FIG. 4, the direction of the current is reversed each time the current is turned on. For example, the voltage across the coil 106 is applied during time period t.sub.1 and is turned off during time period t.sub.2. The voltage is turned on again during time period t.sub.3 but the polarity is reversed. As a result, the current in the coil 106 is positive during time period t.sub.1 and negative during time period t.sub.3. The current becomes positive again during time period t.sub.5 and so on and so forth. The direction of the current dictates the direction of the magnetic field generated by the current under the right hand rule. When the direction of the current in the coil 106 is reversed, the direction of the magnetic field is reversed. By programming the controller 102, the time periods, t.sub.1, t.sub.2, t.sub.3 . . . , can be adjusted to produce a desired magnetic field according to specification.

(14) In FIG. 3A and FIG. 4, during time period t.sub.1, t.sub.3, t.sub.5 . . . , the current in the coil 106 does not reach the maximum value,

(15) $\frac{V}{R},$
before it is switched off. FIG. 5 illustrates a variable current supplied to the coil 106 that reaches the maximum value

(16) $\frac{V}{R}$
within approximately 5τ and maintains the maximum value for an extended time before it is switched off. After it is switched off, the current drops down to zero within a time period of 5τ. The current is turned off during time period t.sub.2 and is turned back on during time period t.sub.3. During time period t.sub.3, the current stays at the maximum value,

(17) $\frac{V}{R},$
for a majority portion of the duration. When the current reaches the maximum value, the magnitude of the magnetic field induced by the current reaches its maximum and the maximum magnetic field is maintained for the majority portion of the duration. In some embodiments, the magnetic field is used as a triggering mechanism of an exothermic reaction. The magnitude, the polarity and/or the variability of the magnetic field are characteristics or parameters that should be carefully determined in accordance to the re requirements of the exothermic reaction or reactor. Based on the requirements, the controller 102 can be programmed to control the H-Bridge Circuit 104 to supply the current to the coil 106 according to specification.

(18) To produce a magnetic field of a desired magnitude or polarity, the current in the coil 106 can be adjusted as well as the placement of the coil or coils 106. FIGS. 6A-6D illustrate different placements of one or more coils 106. In FIG. 6A, a coil 106 is wrapped around a reactor 600 longitudinally. The magnetic field {right arrow over (B.sub.1)} produced by the current in the coil 106 runs parallel to the {right arrow over (x)} axis. FIG. 6B illustrates a coil 106 configured to generate a desired magnetic field {right arrow over (B.sub.2)} along the {right arrow over (y)} axis. The coil 106 is placed on top of the reactor 600.

(19) To enhance the strength of a magnetic field produced by a coil, multiple coils arranged in parallel can be used as shown in FIG. 6C and FIG. 6D. In FIG. 6C, a large coil 112 is wrapped around a reactor 600 longitudinally. Two small coils 114 and 116 are placed in parallel with the large coil 112, one on top of the reactor 600 and one beneath the reactor 600. The magnetic fields generated by the three parallel coils, {right arrow over (B.sub.3)}, {right arrow over (B.sub.4)}, {right arrow over (B.sub.5)}, run parallel to the {right arrow over (y)} axis and enhance each other. The total magnetic field is the vector summation of the three magnetic fields.

(20) FIG. 6D shows another configuration of multiple coils so arranged to generate a magnetic field of a desired magnitude and polarity. Around the reactor 600, the coils 118 and 120 are placed horizontally on top of and horizontally beneath the reactor 600 respectively, while the coils 122 and 124 are placed vertically to the right and vertically to the left of the reactor 600 respectively. The coils 118 and 120 produce magnetic fields {right arrow over (B.sub.6)} and {right arrow over (B.sub.7)} that run parallel to the {right arrow over (y)} axis. These two magnetic fields, {right arrow over (B.sub.6)} and {right arrow over (B.sub.7)}, enhance each other. The sum of these two fields is {right arrow over (B.sub.y)}={right arrow over (B.sub.6)}+{right arrow over (B.sub.7)}. Along the {right arrow over (x)} axis, the two vertically placed coils, 122 and 124, generate a magnetic field respectively. The sum of these two fields is {right arrow over (B.sub.x)}={right arrow over (B.sub.8)}+{right arrow over (B.sub.9)}. The two magnetic fields, {right arrow over (B.sub.x)} and {right arrow over (B.sub.y)}, combine to yield a resultant magnetic field {right arrow over (B)}={right arrow over (B.sub.x)}+{right arrow over (B.sub.y)}. This resultant magnetic field is designed to trigger an exothermic reaction in the reactor 600 in accordance to the requirements of the exothermic reaction or the reactor 600.

(21) In yet another embodiment, a Helmholtz coil may be employed to generate a uniform magnetic field inside the reactor. The placement of the coil determines the orientation and polarity of the field. The Helmholtz coil is configured to generate a magnetic field of a desired magnitude to trigger an exothermic reaction.

(22) In the above description of FIGS. 6A-6D, the current supplied to the coils 106 is assumed to be the same, for the convenience of illustration. In some embodiments, the current supplied to the coils 106 may be different, depending on the desired strength, polarity and/or orientation of the magnetic field. For instance, in FIG. 6D, when the current supplied to the coil 118 and 120 is twice as large as the current supplied to the coil 122 and 124, the magnetic field {right arrow over (B.sub.y)} is twice as large as the magnetic field {right arrow over (B.sub.x)}, yielding a resultant magnetic field {right arrow over (B)} of a different orientation and magnitude.

(23) In the above description of FIGS. 6A-6D, the magnetic fields generated by the coils 106 are static when the current supplied to various coils are DC. With AC currents, the generated magnetic fields are variable. The frequencies with which the magnetic fields shift directions and/or vary in magnitude are determined by the frequency of the AC currents. For example, an AC current of 50 Hz supplied to the coil 106 in FIG. 6A will produce a sinusoidal magnetic field {right arrow over (B)}. The direction of the magnetic field {right arrow over (B)} oscillates along the {right arrow over (x)} axis at a frequency of 50 Hz.

(24) In some embodiments, the AC currents supplied to the different coils are phase-shifted relatively to each other. For example, in FIG. 6C, the AC current supplied to the coil 114 and 116, I.sub.1, is 180° shifted from the AC current supplied to the coil 112, I.sub.2, as shown in FIG. 7A. In one embodiment, the two AC currents are phase-locked to create a steadily oscillating magnetic field of the same frequency as the AC currents.

(25) In some embodiments, the currents supplied to the different coils may be phase-shifted relatively to each other and may be of different amplitudes. For example, as illustrated in FIG. 7B, the current supplied to the coil 114 and 116, I.sub.1, and the current supplied to the coil 112, I.sub.2, are phase-shifted 180° relatively to each other. Besides the difference in phase, the two currents, I.sub.1 and I.sub.2, also differ in amplitude. As a result, the resultant magnetic field differs from that shown in FIG. 7A, because the magnetic field generated by a current carrying coil is proportional to the amplitude of the current according to Ampere's law.

(26) In FIGS. 7A and 7B, two-phase currents are used to generate a desired magnetic field as a triggering mechanism of an exothermic reaction in the reactor 600. Multi-phase currents, e.g., currents supplied by a three-phase circuit, can be used to generate a rotating magnetic field. FIG. 7C shows a balanced three phase currents, I.sub.1, I.sub.2, and I.sub.3. All three currents are of the same amplitude but each is 120° shifted from the next one. The magnetic field generated by the currents can be expressed as {right arrow over (B)}(sin αt+ sin(αt+120)+ sin(αt+240)) and is a rotating magnetic field.

(27) In some embodiments, a static magnetic field generated by a DC current supplied to the coil 106 shown in FIG. 6A can be used to trigger certain types of exothermic reactions in the reactor 600. The magnitude and/or the polarity of the magnetic field can be controlled by the current and the placement of the coil 106, in accordance to the requirements of the exothermic reaction.

(28) In some embodiments, an oscillating magnetic field generated by the AC current supplied to the coils 118, 120, 122, and 124 can be used to trigger a certain type of exothermic reactions. In some embodiments, a rotating magnetic field generated by a balanced three-phase current system supplied to the coils 112, 114, and 116 can be used as triggering mechanism.

(29) The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.