US Patent 9877359 Device for evaporating a volatile fluid

An assembly for evaporating a volatile fluid includes a device and a refill which are detachable from one another: wherein the device comprises a magnetic induction coil configured to operate with an alternating current passed therethrough at a frequency of between substantially 20 KHz to substantially 500 KHz; the refill comprises a fluid reservoir containing the volatile fluid, a wick and at least one magnetic susceptor arranged to heat the wick predominately by magnetic hysteresis when said alternating current is passed through the induction coil, wherein the magnetic susceptor has a coercivity of substantially 50 ampere/meter (HC) to substantially 1500 ampere/meter (HC). Refills, devices and methods of operation are also described.