An evaporator includes a housing, a bottle containing a substance to be evaporated, a wick having a lower portion disposed within the bottle and an upper portion protruding from the bottle, a heating device disposed within the housing at a position proximate to the upper portion of the wick, and an adjustment...http://www.google.com/patents/US6931202?utm_source=gb-gplus-sharePatent US6931202 - Electrical evaporator with adjustable evaporation intensity
