High temperature heating media

Take up more floor space than radiators. Likelihood of fairly high-temperature gradients when using high-temperature heating media. 

May produce large temperatures gradients on high-temperature heating media if poorly sited. 

CONANT, A. R. and SEIFERT, W. F. (1963) Chem. Eng. Prog. 59 (May) 46. High temperature heating media Dowtherm. 

With reaction temperatures above 300 °C intermediate cooling can still be performed directly with boiling water, whereas in a fixed bed a high-temperature heat-transfer medium must be used as coolant (see next section). 

OTHER COMMENTS used as a high temperature heat transfer medium used as an odorant in perfuming soaps useful in organic synthesis, resulting in epoxy resins, high temperature lubricants, specialty plasticizers, varnishes, artificial sweeteners, fire retardants, and... 

Since atmospheric-pressure (or near atmospheric-pressure) SSD involves the use of a high-temperature drying medium (i.e., superheated steam at a temperature higher than 100 °C), this type of process may not be appropriate for heat-sensitive materials such as fruits, vegetables, herbs and spices, and many other biomaterials. For this reason, an alternative drying technique has been developed to combine the advantages of SSD with an ability to conduct drying at a lower temperature. The proposed alternative is based on the fact that water vaporizes at a lower temperature if the pressure of the system is lower superheated steam can then be produced at a lower temperature under such a lower pressure. 

The ideal high level heat-transfer medium would have excellent heat-transfer capabiUty over a wide temperature range, be low in cost, noncorrosive to common materials of constmction, nondammable, ecologically safe, and thermally stable. It also would remain Hquid at winter ambient temperatures and afford high rates of heat transfer. In practice, the value of a heat-transfer medium depends on several factors its physical properties in relation to system efficiency its thermal stabiUty at the service temperature its adaptabiUty to various systems and certain of its physical properties. 

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