What are the main contents of the operation of the steel rolling heating furnace? We help everyone understand it
What are the main contents of the operation of the steel rolling heating furnace? Do you often need to use the steel rolling heating furnace? In order to avoid some mistakes in the operation process and cause harm to yourself, you need to read it carefully. Content compiled by my friends. Steel rolling heating furnace 1. Steel rolling Steel rolling changes the ingot between the rotating rolls, and the pressure processing process of the shape of the billet is called steel rolling. The purpose of steel rolling is the same as other pressure processing. On the one hand, it is to obtain the required shape, such as: steel plate, strip steel, wire rod and various types of steel, etc.; on the other hand, it is to improve the internal quality of steel. Steel, boiler steel, pipeline steel, rebar, rebar, electrical silicon steel, galvanized sheet, tinned sheet, including train wheels are all processed through the rolling process. 2. Heating furnace In the metallurgical industry, a heating furnace is a device (industrial furnace) that heats materials or workpieces (usually metal) to a rolling temperature. Heating furnaces are used in many industries such as petroleum, chemical industry, metallurgy, machinery, heat treatment, surface treatment, building materials, electronics, materials, light industry, daily chemicals, and pharmaceuticals. Steel rolling heating furnace 3. The operation of steel rolling heating furnace mainly pays attention to the following aspects: Kehua pointed out that the control of the thermal system is usually automatic in the early stage when all the regulators are put into operation, and the setting of the regulator comes from the process specification. Manual operation is used after the automatic regulator fails or is repaired, and manual operation can be used in the event of an accident or damage to the automatic components. In order to maintain the long-term and effective use of the furnace, regular maintenance and attention should be paid to its use status; regular cleaning of the iron oxide scale; regular inspection of the water volume, water temperature and water pressure of the water-cooled components in the furnace. When the fan fails or the power is suddenly cut off, the air supply will be gradually interrupted. At this time, the air, gas valve and the main gas valve on the burner should be quickly turned off. Oven: The heating furnace needs to remove the moisture in the masonry before production, after major or minor repairs, that is, the oven. Oven time should consider many factors. Here are some reference data: before a 150t walking beam heating furnace is produced, it takes 36 hours to rise from room temperature to 150 °C, and keep it for 60 hours; it is heated to 350 °C at a heating rate of 15 °C/h, and it is kept for 60 hours; The temperature was raised to 600°C at a heating rate of h, and the temperature was maintained for 48 hours; then the temperature was increased to 8000°C at a heating rate of 20°C/h, and the temperature was maintained for 36 hours; then the temperature was raised to 1200°C at a heating rate of 20°C/h, and the temperature was kept for 36 hours. The total oven time was 14 days. The overhauled oven was heated to 200 °C and held for 4 h; heated to 700 °C at a heating rate of 20 °C/h and then held for 4 h; then heated to 1200 °C at a heating rate of 50 °C/h and held for 4 h. The total oven time is 2 days, which can be extended to 3 days if the time is rich. After minor repairs, the oven was heated to 600°C at a heating rate of 25°C/h and then kept for 6h; and then heated to 1200°C at a heating rate of 50°C/h, and then kept for 4h. Total oven time is about 2 days. Ignition: The gas pipeline in front of the furnace must be cleared of all the air in the pipeline before it is newly built, after major repairs or after long-term deactivation. During operation, pay attention to whether the pipeline and its accessories are leaking. The operation of driving the air in the pipeline and its accessories to the atmosphere outside the workshop is called release, that is, the air is now driven by nitrogen (or steam), and then the nitrogen (or steam) is driven by gas. Effusion is carried out in sections, and is from the main pipe to each main pipe to each branch pipe and finally to the gas pipe before the burner. Pass nitrogen for a specified time and confirm that the replacement is good, stop feeding nitrogen, and then pass gas and drive nitrogen out of the venting pipe. After this step is completed, take samples from the sampling pipe at the end of the gas pipeline and perform a burst test. The vent valve can be closed and this section is considered to be vented. If it fails, it will be driven for a period of time and the burst test will be carried out until it is qualified. The explosion test was carried out in a drum with a diameter of 70~100mm and a length of about 300mm. Light a small fireball on the ground at a safe place a little far from the gas site, move the mouth of the cylinder filled with the sample to the fireball, open the lid of the cylinder and light the sample in the cylinder. If it burns to the bottom of the cylinder, it is considered to be qualified; if it burns quickly after ignition, it means that there is still some air; after ignition, it burns quickly or produces a detonation, indicating that the sample is in the explosion range, and the latter two cases should be Continue to disperse, and make another burst test. When igniting before the burner, firstly supply air to the burner (the air butterfly valve is opened by 20%~30%), then open the gas valve in front of the burner (open 1/3~1/2), and use the oily cotton yarn that burns vigorously. Ignition, and then gradually adjust the amount of gas and air. If the gas is not ignited after spraying, the gas valve in front of the burner should be closed immediately, and the ignition should be restarted after the combustible mixture in the furnace is removed. What are the main contents to pay attention to in the operation of the steel rolling heating furnace? We have carefully sorted it out for our friends above. Kehua hopes that everyone can remember it well, so as to make the operation of our friends safer and others will also be assured.