Bell annealing furnaces generally use hydrogen or hydrogen-nitrogen mixed gas as the protective gas. Hydrogen often has better thermal conductivity than hydrogen-nitrogen, and high-standard hydrogen has a stronger decarburization ability than hydrogen-nitrogen. Also, the surface of the strip steel treated by the bell type annealing furnace using hydrogen as the protective gas has less carbon slag content and more uniform mechanical properties. Therefore, the use of full hydrogen as a protective gas has been commonly used in some metallurgical industries. So what is the bell annealing furnace process? How does a hydrogen annealing furnace complete the annealing treatment of the workpiece?
The main process equipment of the bell type full-hydrogen annealing furnace includes the annealing furnace stand with supply pipeline and discharge pipeline, inner cover, heating cover, cooling cover, valve station and so on. At the beginning of annealing, the steel coils to be annealed should be stacked on the annealing furnace table, the inner cover should be hoisted, and the furnace table, inner cover system and hydrogen inlet valve should be tested for cold sealing. After the test is successful, a nitrogen purge is required, and the heating mantle is hoisted, and then the heating mantle is ignited. When the nitrogen purge meets the conditions, it is necessary to replace the nitrogen in the inner cover with hydrogen purge. When the heating starts, the heating curve should be selected according to different materials for temperature control until the temperature of the steel coil core meets the requirements of the process.
In the working process of the bell type all-hydrogen annealing furnace, the cooling should start from the heating mantle still above the furnace table. Firstly, the air is blown into the heating mantle, and then the heating mantle is removed. Then the cooling cover is hoisted, and the air from the surrounding environment is sucked by the fan on the cooling cover to cool the inner cover. When the circulating atmosphere inside the inner cover reaches the set temperature, the cooling cover fan should stop running. After a while, the spray cooling starts. When the temperature of the steel coil core reaches the set value, the cooling ends, and the cooling cover is removed. Then, a nitrogen purge is performed to replace the hydrogen in the inner cover. Remove the inner cover, and then hoist the steel coil, so that a bell annealing furnace process is completed.
The metal hydraulic bell-type annealing furnace is one of the heat treatment equipment in the machinery industry. That is, the wires or metal parts are placed in different heating furnaces, slowly heated to a certain temperature, and maintained for a period of time. Then cool down them at an appropriate rate, usually is natural cooling, sometimes is controlled cooling. According to different energy sources, wire annealing furnace can be divided into electric annealing furnace, the second is gas energy annealing furnace and the third is petroleum energy LPG annealing furnace. Users can choose according to their own situations.
Sealing Performance of Vacuum Annealing FurnaceJune 21, 2022Both vacuum annealing furnace and vacuum tempering furnace belong to the category of vacuum heat treatment. They can remove scales on the surface of the workpiece, and have the functions of degreasing...view
Our Team Visited Steel D Company (Thailand)March 26, 2025From March 21st to 24th, our team visited Steel D company (Thailand).This is our second visit after two years, and the customer's factory has doubled in size. Starting from using our wire drawing ...view
The Role of Inner Cover in ?Bell Annealing FurnaceDecember 20, 2021¢ñ. Definition of bell annealing furnaceA 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 fur...view
Stainless Steel Wire Drawing Machine - A Game Changer in Metal Fabrication IndustryMay 13, 2023The metal fabrication industry is constantly evolving, and the need for quality products that meet the ever-increasing demands of customers is higher than ever. In this regard, stainless steel wire dr...view
Introduction to the Working Principle of Straight Line Wire Drawing MachineMarch 13, 20231. What is a Wire Drawing Machine?The wire drawing machine is developed and produced using imported, absorbed and digested technology. It is suitable for drawing various metal wires below §¶14mm, incl...view
What Is a Wire Annealing Furnace?May 13, 2023Wire annealing furnaces are an essential component in the manufacturing process of various types of wires. The process of wire annealing involves heating the wire in a controlled atmosphere to increas...view