Annealing and cooling of sanitary stainless steel elbows:
Annealing and cooling of sanitary stainless steel elbows: The sanitary stainless steel elbow annealing furnace is a degree suspension cable type continuous annealing furnace, mainly using natural gas as fuel, so that the working efficiency is the highest and the successive tunnel type is selected. The heat treatment section is divided into preheating zone, open flame heating zone, water-cooling initial cooling zone, water-cooling final cooling zone, and monotonous section. The lengths of each section are: 40m, 4×15m, 3×5m, 3×5m, 1×5m. . By the way, the supporting roller is about 155m long. When disposing of austenitic stainless steel elbows, the skill section speed is 80 meters per minute. Let’s take austenitic sanitary stainless steel elbow fittings as an example to explain the characteristics of each section: the preheating section of stainless steel elbow uses the calming gas of the direct-fired heating section to preheat the strip before entering the direct-fired heating section. When the temperature reaches about 400℃, with heat recovery equipment, the furnace gas is discharged through a variable frequency speed control fan with an air volume of 107530Nm3/h to ensure the furnace pressure and stop the heat recovery. The heating section is divided into four sections of direct combustion, each section has thirty nozzles, a total of 120, the annealing temperature is 1100 ℃, the maximum temperature of the furnace regenerator can reach 1250 ℃, the preheating section and each heating section are equal The equipment has oxygen content measuring instrument and thermocouple. There are five disc-shaped roller table support assemblies installed between different furnace sections. They are happy to quickly change rollers online. Each disc roller assembly is equipped with two ceramic fiber support rollers. The primary cooling zone and the final cooling zone each have three stages of water spray for rapid cooling, and the water spray system is specially designed. Each of the 3 sections of the preliminary cooling zone contains ten sets of nozzles on the upper and lower sides of the strip, each nozzle is equipped with four nozzles, and each nozzle is equipped with a manual dispatch valve and a pressure gauge. After passing the preliminary cooling section, the strip temperature When the temperature drops from 1100°C to about 500°C, the final cooling zone contains a three-stage cooling box in the cooling section. Each cooling section is equipped with eleven sets of AISI304 stainless steel spray pipes, and each spray pipe is equipped with eight spray heads. The spray heads of adjacent spray pipes are staggered to ensure even spray water. After passing through the final cooling section, the temperature of the strip will usually be It drops below 80°C. The monotonous section includes squeezing rollers, air blowing and eight sets of hot air nozzles to dry the surface of the steel strip.