Radio-frequency heating

An innovative companion technology to SVE is radio frequency heating of the soil (42,43). Heating the soil increases the volatilization of the containments which are removed by SVE. Antennae are installed near the center of the contaminated area the radio frequency energy appHed through the anteimae heat the soil to target levels of 100 to 150°C. 

TPEs can be bonded to other materials by adhesive, heat bonding, electromagnetic filling, radio frequency, heat-sealing lamination, friction and spin welding, and ultrasonic welding. For TPUs, the most widely used techniques are radio frequencies, and ultrasonic and hot stamping. A few typical applications include football bladders, valves, and conveyer belts. 

Thermal enhancement of volatilization.19 21 Volatility of contaminants increases greatly with temperature, so several techniques have been developed to raise soil temperature, including the injection of hot air or steam, electrical resistance heating, and radio frequency heating. 

Lowe, D.F., Oubre, C.L. and Ward, C.H., Eds., Soil vapor extraction using radio frequency heating, in Resource Manual and Technology Demonstration, Lewis Publishers, Boca Raton, FL, 1999. 

A typical liquor formulation for pad application in a continuous or semi-continuous system is given in Table 10.28. Batching for 24-48 hours is followed by backwashing, although the use of radio-frequency heating to give a batch temperature of 50-60 °C can reduce the treatment time to 2-4 hours. 

Shorten or even eliminate the relaxation delay is only effective for relatively fast-relaxing nuclei, and can lead, if decoupling is turned on, to serious radio-frequency heating problems if the relaxation delay is very short. Recently, Kupce and Freeman have introduced an alternative... 

Figure 2.4 Schematic diagram of an ICP torch. The sample is carried into the torch by the carrier argon gas, and is ignited by radio-frequency heating from the RF coils. The tangential argon flow lifts the flame from the burner, preventing melting. The position of the detector in axial or radial mode is shown. (From Pollard et al., 2007 Fig. 3-3, by permission of Cambridge University Press.)...

In situ thermal Injects heat above the water table via Joule heating, radio frequency heating, or means to promote volatilization of contaminants Difficulty in attaining uniform heat distribution... 

T0400 IIT Research Institute, Radio Frequency Heating... 

The technology cannot be used if large metal objects are buried in the treatment zone. In general, ThermNet technology is not recommended for the remediation of saturated soils. If saturated soil is to be remediated by radio frequency heat (RFH), the treatment zone should be dewatered prior to treatment. The technology can only be used to remove contaminants that can be volatilized at soil temperatures that the system can practically achieve throughout the treatment zone. Contaminants in silty or clayey soils are usually strongly sorbed and are difficult to remove. 

The high costs of using radio frequency heating limit its use to very expeusive remediation projects that require a uuique heating method (D15838X, pp. 2-9). 

Van Arkel refining by transporting and thermally dissociating actinide iodides has been applied to Th and Pa metals. Bulk metal instead of (brittle) wire can be obtained by dissociating the iodides on a radio-frequency heated sphere of the corresponding actinide metal. 

A continuous monocrystalline sapphire (A1203) fibre has been prepared as single-crystal fibres by LaBelle and Mlavsky using a modified czochralski puller and radio frequency heating. The technique adopted in this method is called edge-defined film-fed growth (EFG) [18-22], Figure 3.4 shows a schematic of the EFG method. 

There are basically two forms of dielectric heating radio-frequency and microwave. Radio-frequency heating uses a frequency (13 to 100 MHz) to generate heat in polar materials. The electrodes are generally designed into the platens of a press, and they are... 

Radio frequency heating, 500 Steam stripping, 500 Vacuum extraction, 500 Aeration, 501 Bioremediation, 501 Soil flushing/washing, 502 Surfactant enhancements, 502 Cosolvents, 502 Electrokinetics, 503 Hydraulic and pneumatic fracturing, 503 Treatment walls, 505 Supercritical Water Oxidation, 507 Solid Solution Theory, 202 Solubility products, 48-53 Metal carbonates, 433-434 Metal hydroxides, 429-433 Metal sulfides, 437 Sorption, 167 See Adsorption Specific adsorption, 167 See Chemisorption Stem Layer, 152-154 Sulfate, 261... 

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