Re: Firebrick

The question was asked as to the purpose of fire brick on an oil burner. While I am a fireman at SVRy, I would draw from experience with oil fired boilers in heating service. The main function of the firebrick is to reflect intense heat back into the fire to vaporize small droplets of oil so that combustion is more efficient. On heating boilers, some simply have a target wall of refractory with the cast iron or steel sides of the boiler exposed to the flame. After a year of operation, the exposed metal surface is usually covered with soot at best to oily goo in the cooler areas such as back corners. In units equiped with some type of refractory chamber, there is typically no deposit of unburned yuck in that area as the refractory becomes hot enough to combust any carbon/unburned fuel that touches it (burning diesel). I believe the same is generally true with an oil burning locomotive. The flash wall under the fire door along with the brick on the bottom and sides provides the same hot surface to aid combustion. The only surfaces that acually need to be protected from the fire by the brick would be the steel supporting structure that does not have water behind it which is below the brick where the grates would be if it were a coal burner. With the used motor oil we burn, some carbon does build up on the flash wall surface and has to be cleaned every few service days, with chisel and hammer.