Pressure Atomizing Oil Burner Equipment and Systems – Firing Assemblies
A field modified high pressure fuel oil atomizing firing head by Fess Oil Burners, Toronto, an acknowledged early pioneer in oil burner engineering and manufacture in Canada; with classic black/green enamelled finish, long-reach, 3/8 inch, brass, oil delivery tube, inlet oil filter and oil-flow shut-off valve, and modified with the addition of a Honeywell dripples, automatic, oil pressure control, check valve, Fess, Model J31, Circa 1940. [see also ID#261]
Features: Original high tension ignition cables
Technical Significance:
A marker of the times in the evolution of automatic oil heating for the Canadian home, this 24 inch, long-reach firing assembly, typical of the period, was designed for “conversion” installation. Such installations were typically found in gravity style, home warm air heating furnace installations in the early years of the 20th century. Here coal grates would be removed, and oil burner refractory would be hand built in its place and a firing head would be inserted, See ID# 243, 244,245.
This firing head, typical of the period, slides into a large (4″ to 5″) fire tube [gun]. It delivers oil at up to 100 psi. to an oil atomizing spray nozzle through a 3/8″ brass, oil delivery tube.
Turbulated air under pressure is forced through an air cone [see ID# 64 and 265] where it is mixed with the atomized oil spray and ignited by an electrically generated spark [See ID# 255 and 256] jumping between two carefully positioned electrodes. High tension insulated cables carry the electrical current to the electrodes, through fragile, porcelain electrical insulators.
The oil atomizing nozzle, first developed in the 1920’s would be a marvel of its times, in product engineering and design, as well as in mass production manufacture. Designed to produce a variety of air patterns, with different combustion characteristics, it would survive relatively unchanged through to the 21st century.
This firing assembly, modified 10 years or so after first installation, suggests something of the long “shelf life” of the basic technology.
A performance characteristic of such firing assemblies was the tendency to eject oil into the firebox at below the specified design pressure, 85 to 100 psi. The result was poor combustion and a smoky, smelly fire. Usually caused by a fuel pump failing to open at the proper pressure, the dripples valve would provide a quick fix, a less expensive alternative to pump repair or replacement.
Industrial Significance:
This high pressure, high voltage, fuel oil atomizing firing head by Fess Oil Burners, Toronto, stands as a marker of the earliest pioneering work of a Canadian company in the engineering and manufacture of automatic heating equipment designed for the Canadian home.
This basic firing head configuration would meet many of the needs of the market-place, and satisfy minimal safety requirements through to the end of the 20th century
During this period, however, engineering applications progressed well beyond the “conversion” market, to smaller, more efficient, unitary, packaged automatic oil heating equipment, for both warm air and hot water [hydronic]. As a result firing assemblies would become much more compact and sophisticated in design.
Yet, the basic engineering design trend had been set by the early 1930’s. Fragile and often temperamental, as it was, firing assemblies of this essential configuration, modified and customized for different applications, would remain the standard for high pressure atomizing oil burners to the end of the 20th century.