The Role of Inner Cover in ​Bell Annealing Furnace

Ⅰ. Definition of bell annealing furnace

A type of annealing furnace is the bell-type annealing furnace. It primarily heats the strip steel indirectly via the inner cover of the bell-type annealing furnace. The radiant heat transfer determines the heat that the strip steel can receive to the inner cover wall. And the ability of gas convection heat transfer is closely related. The bell-type annealing furnace's inner cover is a component of the bell-type annealing furnace and an essential component for heating the workpiece. So, what are the applications of the inner cover of a bell-type annealing furnace?

Ⅱ. The role of the inner cover of the bell annealing furnace

The main function of the bell annealing furnace is to isolate the steel coil from the combustion space so that the steel coil can be annealed in a protective atmosphere without being oxidized. It can also conduct heat transfer during the heating and cooling process, so the inner cover of the bell-type annealing furnace is essential. It is an indispensable structural component of the bell-type annealing furnace. The main body of the inner cover of the bell-type annealing furnace is a corrugated cylinder welded by high-temperature resistant chromium-nickel steel plates. The upper part is the head, and the upper part of the head is also welded with a lifting ring to lift the three-jaw fixture. Its bottom is a machined sealing flange. This flange is mainly made of plain carbon steel.

The flange of the inner cover is placed on the sealing flange surface of the furnace base. Therefore, the inside of the inner cover of the bell annealing furnace is completely isolated from the outside through the rubber sealing ring's action embedded on the furnace base's sealing surface, which can avoid the entry of air well. A ring-shaped sealing groove is also designed on the flange of the inner cover, and heat-resistant silicone rubber is placed inside to isolate the heating space from the outside, thereby improving thermal efficiency.

Between the ring-shaped sealing groove and the corrugated cylinder, a water tank is also dedicated to cooling water. The function of this water tank is to prevent heat radiation from the furnace rubber sealing ring to extend its service life. There is also a water groove on the wall of the sealing groove, which is mainly to facilitate the discharge of cooling water during spray cooling. When the inner cover does not need to be used and is placed in other positions, in order not to damage the sealing plane, there are special support stubs on the ground along the outer edge of the flange.

According to different energy sources, wire annealing furnace can be divided into electric annealing furnace, gas energy annealing furnace and petroleum energy LPG annealing furnace.