DE565675C - Method and device for glowing - Google Patents

Description

Method and device for annealing incandescent embers, in particular metallic annealing material, is mainly heated by thermal radiation. In addition to the temperature gradient, the heat absorption capacity depends on the radiation number of the surface of the material to be annealed "/ _. B. bare brass bands have radiation numbers of 0 # 3 <C <i; warm, dusty substances, in particular earth, graphite or soot, have radiation numbers of 4 <C <4 # 8. All other things being equal, only change is possible the heat-absorbing surface to increase the amount of heat to be absorbed in the unit of time by a multiple. By sprinkling a thin layer of such dust-like earths, as is generally known, the heat radiation coefficient of the annealing material surface, which is undesirable for the heat absorption capacity, can be largely approximated to that of these earths and thus the In practice, this means an increase in efficiency and therefore better utilization of the furnace.

According to the invention, this method is known in principle in continuous metal belt furnaces where the surface of the material to be annealed is particularly large in relation to the quantity of material to be annealed in the furnace, as a result Made use that the heat-dark substances at the oven entrance in a thin layer applied to the surface of the material to be annealed and removed again from the material to be annealed at the furnace outlet will.

The illustration shows an exemplary embodiment. The ribbon-shaped annealing material A is continuously conveyed through the conveyor furnace B in a known manner. the Heating occurs mainly through thermal radiation from the inner furnace walls C off. In front of the entrance to the furnace there is a vibrating chute D, which the covered the whole range and a wafer-thin layer of dust made of heat-dark fabric drops on the belt in a certain amount. The dust gets through at the furnace exit the suction pipe .E removed again. The fan F conveys the dust material in the dust separator G, from whose storage container it is through the screw H the Shaking chute is fed back. The storage container as well as all lines are surrounded by thermal insulation J, which prevents the dust from dying off when it is glowing lost heat uselessly.

Instead of applying dusty material to reduce the Radiation number the surface of the material to be annealed can also be an application of a by adhesion of adhesive coating agent, which also adheres to the underside of the tape. take place, e.g. B. graphite mixed with water, which through an oven outlet located wiping-washing or -brushing device removed again «-can earth.

Claims (3)

PArr @ raNsrr, LCHE: t. '\ -experienced in increasing the' heat absorption rate of annealing material in the form of a belt or conveyed on belts with a bright surface in. continuous furnace, characterized in that at the furnace entrance by hand or by machine a powdery, heat-dark substance, e.g. B. warm earth, Graphite, charcoal or soot, applied in a thin layer to the surface of the annealing material and at the furnace outlet by wiping, brushing, blowing, washing, vacuuming or is removed again in another way. 2. The method according to claim r, characterized in that that the powdery substance is moved in a closed circuit by after suction at the exit of the furnace by a fan system, a dust separator is supplied with a storage container, which feeds the application system at the furnace inlet. 3. Device for performing the method according to claim 2, characterized in that that the entire dust conveying and storage devices to prevent heat loss are isolated. Method according to claim r, characterized in that when used of a substance adhering by adhesion, the band to be glowed also on the underside is coated with this substance.