Heat inductor

To start the reaction in the reactor input, we have a small surface with the function of a heat inductor where the temperature of the gaseous mixture increases very rapidly to attain the inductor temperature. Inside the reactor the inductor surface operates as a stripping heat surface ... 

Coreless furnaces derive their name from the fact that the coil encircles the metal charge but, in contrast to the channel inductor described later, the cod does not encircle a magnetic core. Figure 8 shows a cross section of a typical medium sized furnace. The cod provides support for the refractory that contains the metal being heated and, therefore, it must be designed to accept the mechanical loads as well as the conducted thermal power from the load. 

The term channel induction furnace is appHed to those in which the energy for the process is produced in a channel of molten metal that forms the secondary circuit of an iron core transformer. The primary circuit consists of a copper cod which also encircles the core. This arrangement is quite similar to that used in a utdity transformer. Metal is heated within the loop by the passage of electric current and circulates to the hearth above to overcome the thermal losses of the furnace and provide power to melt additional metal as it is added. Figure 9 illustrates the simplest configuration of a single-channel induction melting furnace. Multiple inductors are also used for appHcations where additional power is required or increased rehabdity is necessary for continuous operation (11). 

The bath is normally at a temperature in the range 620-710°C, depending on whether the coating material is an aluminium-silicon alloy (for use in high-temperature conditions) or pure aluminium (for corrosion prevention). It is heated by inductors, by resistance heaters or by an external flame. The pot will usually be refractory lined unless cast-iron pots are needed to ensure adequate heat transfer from an external flame. As molten aluminium is extremely aggressive towards ferrous metals, replacement of cast-iron pots is fairly frequent. Refractory-lined pots obviously do not have this drawback, although the bath hardware, in particular the sinker roll and support mechanism, will still be attacked and need replacement at intervals. 

From Fig. 10.13, we see the latter condition is fulfilled in the first three cases, but not in the fourth case. The most stable situation is obtained with Rx. The choice R = RcosL is however usually adopted when the power supplied to the resistor must be measured. The control of temperature in the real (dynamic) case is much more complex. The problem is similar to that encountered in electronic or mechanical systems. The advantage in the cryogenic case is the absence of thermal inductors . Nevertheless, the heat capacities and heat resistances often show a steep dependence on temperature (i.e. 1 /T3 of Kapitza resistance) which makes the temperature control quite difficult. Moreover, some parameters vary from run to run for example, the cooling power of a dilution refrigerator depends on the residual pressure in the vacuum enclosure, on the quantity and ratio of 3He/4He mixture, etc. 

Similarities with classical waves are considered. In particular we propose that the networks of electric resonance RLC circuits may be used to study wave chaos. However, being different from quantum billiards there is a resistance from the inductors which gives rise to heat power and decoherence. 

The simple series RLC electrical circuit of Fig. 9.2 consists of a direct-current (DC) power source (here a 3-V battery), a relay, and three loads in series a resistor of resistance R, a capacitor of capacitance C, and an inductor of inductance L. Assume first a DC potential E = E0, in series with R, C, and L the capacitance stores charge, the inductance stores current, and the resistance dissipates some of the current into Joule13 heating. The arrow shows the direction of the current (which, thanks to Franklin s unfortunate assignment, is the direction of motion of positive holes—that is, the opposite of the flow of negative electrons) the relay across L avoids conceptual difficulties about an initial current through the inductor. The current is usually denoted by I (from the French word "intensite"). These three components (R, C, and L) will be explored in sequence. 

Figure 3.36 shows the heating principle of the zone refining purification procedure and also introduces the geometric and material conditions that characterize the process. It also shows how the stick transfers heat to the contiguous medium. For a correct introduction to this problem, we assume that the production of heat by the inductor has Gaussian behaviour, so, for the heat generation rate, we can write Eq. (3.124) where the source amplitude (watt/m ) is A, f(t) is a dimensionless function that keeps the maximum temperature for the inductor constant and kj and k2 are the constants with dimension ... 

The modern FZ process is carried out in the growth chamber of a large FZ machine, see Fig. 3.6. The FZ setup consists of the upper and lower vertical pulling spindle carrying the polycrystalline feed rod and the thin rod-like seed crystal at their ends, respectively. Between them, the pancake-shaped inductor, a one-turn RF coil is placed for contactless inductive heating. 

Fig. 3.2. Needle-eye technique for large FZ crystals on bottom the growing crystal, on top the melting feed rod, in between the molten zone heated by the inductor schematic cross section (a) and photograph (b) of an FZ process (100 mm crystal diameter)...

In using conventional LC-based switching regulators, we may have noticed that their constituent inductors and capacitors do get fairly hot in most applications. But if, as we said, these components are reactive, why at all are they getting hot We need to know why, because any source of heat impacts the overall efficiency And efficiency is what modern switching regulators are all about ... 

What about the current rating This is largely determined by the amount of heat dissipation the inductor can tolerate. But its thermal resistance (in degC/W) is not determined by the winding configuration, rather by the exposed area of the inductor, and other physical characteristics. Therefore, whether in series or in parallel configuration, we have to maintain the same total I2R loss. For example, suppose we call the current rating in parallel as Ip ,... 

Figure 7-93. Schematic of reactor for silicon carbide production in discharge zone of hydrocarbon plasma (1) RF generator (2, 3) inlet of reagents (4) distributor of initial products (5) porous wall (6) discharge zone (7) inductor (8) quenching zone (9) heat exchanger (10) filter.

Article 6 passes through inductor 7 of an HFC generator where it is heated above the polymer melting point and then passes through the spraying zone. Powder particles stick to the article or rebound from its surface, get to the rarefaction zone and are drawn into the channel of pipeline 1. The installation is loaded with the powder from bin 8. The ready coating is post-fused in the second inductor 9. 

Wiegant FA, Malyshev lY et al (1999) Dinitrosyl iron complexes with thiol-containing ligands and S-nitroso-D, L-penicillamine as inductors of heat shock protein synthesis in H35 hepatoma cells. FEBS Lett 455 179-182... 

The magnetic profiler uses independently exited electromagnets installed across the width of a dryer cylinder. As the cylinder, which is a conductor, passes through the magnetic flux lines, eddy currents (which produce heat) are induced in the shell. This heat provides very precise and discrete control of the moisture profile. The eddy current heating produced can be 100 times higher than the input power to the inductor in the 150-mm width band. Commercial tests show that these profilers control the moisture within h-0.3% and increase the machine speed up to 5%-10% [48]. 

An induction heating device consists of two components, a high-frequency generator and an induction coil, the so-called inductor. An alternating voltage is applied to the induction coil which results in an alternating current in the coil... 

Induction Heating, Fig. 4 Current distribution and penetratirai depth in a longitudinal field inductor... 

Heating a workpiece in a longitudinal field inductor, the penetration depth and thus the thickness of the heated surface layer can be controlled by the frequency of the alternating voltage. 

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