Recirculating high velocity hot air sterilizing device having improved internal insulation structure

A recirculating, high velocity hot impingement air sterilizer has an inner housing that defines a chamber adapted to receive dental instruments or the like to be sterilized by hot impingement air jets flowed through the chamber by a compact fan, duct and heating coil assembly exteriorly secured to the inner housing. A specially designed insulating jacket structure envelopes and removably receives the inner housing, the jacket structure having a flexible, hollow outer skin portion filled with and captively retaining a suitable insulating material. The jacketed inner housing is received within an outer housing and defines therein a cooling space which extends around a major portion of the insulating jacket structure. Cooling air is flowed through such cooling space by a small fan secured to the inner surface of a removable back panel portion of the outer housing. By simply removing the back panel portion, and then removing a back portion of the insulating jacket, access to the main fan and heating coil structure is quickly and easily provided to repair or replace the same without removing the inner housing. The flexible outer skin portion of the insulating jacket prevents the insulating material from damage or dislodgement into either housing during the repair or replacement of the main fan and heating coil structure.