Abstract: Assemblies for increasing airflow and heating efficiency in a multi-shelf food heating device having a base, a plurality of circular vertically stacked trays, and a top, wherein the airflow within the device is assisted by a fan is disclosed. One assembly involves a biasing system supported in the base for biasing the motor in place. Another assembly involves a thin, substantially planar constructed heater and a radial fan supported within a chamber of the base of the device, wherein the heater is aligned with the movement of the airflow within the chamber so that the airflow therein is substantially unobstructed by the heater. Another assembly involves providing the base with a wall substantially surrounding and adjacent an air inlet in the base to define a cavity into which substantially all of the airflow from the air inlet is directed, so that the motor is continuously cooled during operation of the device.

Abstract: A two-stage air cleaner with side-by-side elements. The cleaner has a first element (30), a second element (32) which itself may have a safety element (35). The first element (30) is preferably a conical inertial separator having a scavenge outlet (38). The second element preferably employs a pleated filter (50) which receives cleaned air (indicated by arrows 104) which passes through the filter (as indicated by arrows 106) to the outlet tube (56). In an alternative embodiment, pleated filter (50a) may have a reverse taper corresponding to that of the conical inertial precleaner (30a), thereby reducing the size of the housing.

Abstract: An air cleaner and an intake tube having an air permeable portion at one end thereof forms an inner support for the air cleaner, but which is detachable therefrom. In one embodiment, the air cleaner is a single integral unit which is disposed of after use. The unit includes a tubular filter element having an opening sized to receive the intake tube, a shell surrounding the filter element, one end cap sealing and forming a junction between the filter element, shell and intake tube at one end, another end cap sealing and forming a junction between the filter element and shell at the other end and having an aperture through which the intake tube is inserted and at least one air intake aperture in one of the caps. In another embodiment, a centrifugal separator and a dust collector cap which may be emptied from time to time to extend the life of the air cleaner is incorporated therein. The intake tube may also have a right angle bend for side mounted filters.