Abstract: An apparatus for mounting a portable ventilation fan at an access port in the wall of an enclosure. The apparatus comprises a fixable base plate having a first opening extending therethrough, and which is detachably mounted to the port with the first opening in alignment with the port opening. A swing plate having a second opening extending therethrough is pivotably coupled to the base plate for pivotal movement between a closed position in which the first and second openings are aligned and an open position. The fan is detachably coupled to the swing plate so that the fan is in alignment with the second opening, whereupon when the swing plate is in the closed position, the fan is operable to promote a flow of air through the access port via the first and second openings.

Abstract: A rotary burner has fuel discharge nozzles arranged exclusively in the high velocity zone of combustion air flow. The resulting annular flame pattern has a central region adjacent to the burner hub which is essentially combustion free.