Abstract: A process and a device for monitoring the imperviousness of a radiant tube fired by a gas burner is disclosed. From a burner control a burner signal is derived that may have at least the states BURNER OFF when the burner is switched off and BURNER ON when the burner is switched on. In addition, the exhaust gas flow of the burner is monitored and an exhaust gas signal is derived there from which may at least have the states EXHAUST GAS OFF when there is no sufficient volume flow of exhaust gas flowing out of the radiant tube, and EXHAUST GAS ON when there is a correctly flowing exhaust gas. The burner signal and the exhaust gas signal are linked with each other for outputting a failure signal in case the combination BURNER ON and EXHAUST GAS OFF results.

Abstract: A method of adjusting the mass stream and flow density of a finely divided, fine-grained solid fuel is described. The method uses a dosing container having a fluidized bed at its bottom part and into which the solid fuel is charged above the fluidized bed. A fluidizing gas is adjustably fed to the bottom part of the container and a compensation gas is fed to the upper part of the latter. Mass stream parameters and density are measured in the discharge or supply pipe communicating with the fluidizing bed and the required weight of flow of the fluidizing gas is computed by a computer. In this manner, the regulation of the mass stream is effected by adjusting the loose density of the charge of the dusty material in the container.