Glossary of solvents and related terms used in various industries
There are 47 entries in this glossary.H
| Term | Definition |
|---|---|
| HCFC |
HCF is a chlorofluorocarbon is an organic compound that contains carbon, chlorine, and fluorine. HCFC are hydrochlorofluorocarbons which contain hydrogen in addition to carbon, chlorine, and fluorine. Most commonly, the term refers to a family of volatile derivatives of methane and ethane. Many CFCs have been widely used as refrigerants, propellants (in aerosol applications), and solvents. The manufacture of such compounds are being phased out by the Montreal Protocol because they contribute to ozone depletion. HCFC solvents have been available for a number of years. They were considered to be a "Stop Gap" product to provide an alternative to CFCs whilst taking into consideration environmental, technical and economic aspects. Although regulations are still being drawn up: production is currently scheduled to cease in 2015 in the European Union and in 2030 for the rest of the world. more info: http://www.arap.org/adlittle/10.html http://jhuntington.uko2.co.uk/hcfc141btext.html |
| Helix |
The part of a spinning band that is machined or twisted into a screw type configuration which causes the liquid in the still to be pumped downward. |
| Hexane |
Hexane solvents are intended for application in chemical industry to produce synthetic types of rubber, polyolefins; in light industry for wool pretreatment; in microbiological industry for extractive purification of protein-vitamin concentrate; in food industry to extract edible fats, as well as to extract volatile oils from essential oil stuff. |
| Hold up |
The amount of liquid required to completely wet the internal surface of the still. This is considered to be the amount of distilland that cannot be recovered from the distillation. |