Method and device for monitoring the working of a furnace

Claim 1

A mobile probe for monitoring the operation of a furnace by making selective visual examination of the walls, internal accessories and the charge of the furnace, comprising a hollow body containing: a. a receiving device to pick up the rays retransmitted by the part of the charge or furnace to be examined, this device comprising least one movable television camera having a head, said device being mounted in a central conduit of the said hollow body; b. at least one optical ray transmitting device also mounted inside the central conduit in a recess made in the head of said camera; c. a focal optical system also mounted inside the central conduit between the transmitting and receiving devices and the material to be examined; a protective element for said focal optical system, said element being supported on at least one annular support having a plurality of recesses uniformly spaced along the inner periphery thereof said recesses being provided to let through optical rays sent out bY said transmitting device and direct towards the charge or a part of the furnace to be examined; d. means for cleaning the surface of said focal optical system facing the material to be examined; e. means for providing cooling water circulation through hollow outside walls of the probe; f. means for providing cooling air circulation in the central conduit around the television camera and the optical ray transmitting device; and g. means for blowing cooling inert gas on to the focal optical system associated with the receiving device, which means is mounted inside the outside walls of the probe.