Axil, both resistive and inductive heaters will produce magnetic fields - A resistive heater can operate on AC or DC but an inductive heater will short out if fed DC. The resistive heater is still equivalent to a conductor which will produce an ac or pulsating dc magnetic field if you choose to feed it with such a waveform and I think that is what we want to use. An inductive heater is essentially a coil which will develop a counter EMF that rounds off your pulse (choking current) while the resistive heater will give you a current waveform with a sharper rise time which is what you want since you are endorsing this much faster field propagation as opposed to thermal propagation to explain the control loop - and I concur. Regards Fran
From: Axil Axil [mailto:[email protected]] Sent: Monday, April 18, 2011 3:53 PM To: [email protected] Subject: EXTERNAL: Re: [Vo]: resistive heaters not for heating? To the best of my knowledge, induction heating is the process of heating electrically conducting object (magnetic types of stainless steel but not non magnetic copper) by electromagnetic induction where eddy currents are generated within the metal and resistance leads to Joule heating of the metal. An induction heater (for any process) consists of an electromagnet, through which a high-frequency alternating current (AC) is passed. Heat may also be generated by magnetic hysteresis losses in materials that have significant relative permeability. The frequency of AC used depends on the object size, material type, coupling (between the work coil and the object to be heated) and the penetration depth. The magnetic field will pass thought non magnetic materials like copper, aluminum, electrical wire insulation or glass without being effected and terminate within magnetic materials. The copper inductive coils in the Rossi reactor probably lie under the inclosing copper header pipe and wrap around the RV. On Mon, Apr 18, 2011 at 3:15 PM, .:.gotjosh <[email protected]<mailto:[email protected]>> wrote: axil, please forgive me if these are ignorant questions: are you sure that the heating elements are "inductive"? isn't there a difference between inductive heating and resistive heating? Isn't it true that inductive heating will not work with copper? On Mon, Apr 18, 2011 at 21:05, Axil Axil <[email protected]<mailto:[email protected]>> wrote: The current producing the inductive heating will flow primarily on the outside surface of the stainless steel reaction vessel (RV) wall due to the skin effect. Little or a reduced current will flow on the inside surface of the RV wall. No magnetic field will exist on the inside of the RV where the hydrogen is pressurized. The magnetic field lines will be parallel to the circumference of the RV cylinder causing the heating current to flow along the skin of the RV. This is prescribed by the right hand rule. The will be a large negative electrostatic field produced by the flowing electrons which form the inductive heating current. This negative current charge will attract the positive hydrogen ions into the oxygen vacancies on the nickel oxide powder lying on the inside surface of the RV wall. This attractive force will supplement the force exerted by the electronegative oxygen atoms within the NiO at or very near the inner surface of the RV wall. At startup, the induced current will be substantial at about 10 amps. On Mon, Apr 18, 2011 at 2:03 PM, .:.gotjosh <[email protected]<mailto:[email protected]>> wrote: Hey Mark! Axil and I have been dancing around this idea also in a recent thread (http://www.mail-archive.com/vortex-l%40eskimo.com/msg45022.html) I have a strong feeling that there are some electro-magnetic effects playing an important role here. and I also found this tidbit on wikipedia: > Nickel is a naturally magnetostrictive material, meaning that in the > presence of a magnetic field, the material undergoes a small change in > length.[41] In the case of nickel, this change in length is negative > (contraction of the material), which is known as negative > magnetostriction and is on the order of 50 ppm On Mon, Apr 18, 2011 at 19:31, Mark Iverson <[email protected]<mailto:[email protected]>> wrote: > Could the magnetic field generated by the resistive heaters be inducing some > other effects that help promote the reaction, or inductively heat the > Nickel??? > > -Mark
