The invention discloses a roller
hearth type plate continuous furnace and a
tempering method thereof. An external circulation concurrent
heating system is arranged on the rear part of a furnace body.The external circulation concurrent
heating system comprises a
hot blast stove, an after-burning device, a circulating fan, a main valve, a hot air pipeline and jetting heating devices. The hot blaststove is provided a furnace gas inlet, an after-burning device installation port, a furnace gas outlet, a
temperature measurement installation port and a
cold air inlet, the furnace gas inlet is connected with a furnace gas outlet of the furnace body through the main valve, the after-burning device installation port is used for installing the after-burning device, the furnace gas outlet is connected with an inlet of the circulating fan, and the
temperature measurement installation port is used for installing a temperature sensor. An outlet of the circulating fan is connected with the jetting heating devices through the hot air pipeline, and one
branch valve is arranged corresponding to each jetting heating device. The jetting heating devices extend into the furnace body and are distributedon the upper surface and the lower surface of a steel plate needing
processing, and are provided with a plurality of nozzles on the sides facing the surfaces of the steel plate, and the lower jettingheating devices are located between
hearth rollers. According to the roller
hearth type plate continuous furnace, during high-temperature
tempering, the adverse
impact caused by an
open fire heatingdevice to the uniformity of the
furnace temperature and the heating uniformity of
steel plates is reduced.