Continuous annealing furnace to utilize afterheat of strip steel in the same casing

Abstract

The present invention discloses one kind of continuous annealing furnace to utilize afterheat of strip steel in the same casing. The continuous annealing furnace includes furnace body, heating unit, strip steel feeding port and strip steel discharging port. The furnace body includes heating and heat insulating casing, high temperature section cooling and preheating casing, middle temperature section cooling and preheating casing, channel and low temperature section cooling and preheating casing, and has strip steel driving wheel train and strip steel discharging wheel train inside both the high temperature section cooling and preheating casing and the middle temperature section cooling and preheating casing. There is also one liquid heat exchange tank for strip steel to be soaked inside in front of the furnace body. The present invention can utilize the afterheat of strip steel obviously.

Description

technical field [0001] The invention relates to an annealing furnace, in particular to a continuous annealing furnace which utilizes the waste heat of strip steel to cool down in the same box. technical background [0002] In order to obtain the required properties, cold-rolled strip generally needs to be annealed. The temperature-related process of heat treatment of strip steel is composed of preheating, heating, (soaking) heat preservation, cooling and other processes. The commonly used strip steel heat treatment furnace types are divided into two types according to the operation mode: one is the gap furnace, such as the bell furnace, the temperature-related process is in the same inner cover, generally there is no preheating process, and the strip steel is stacked in coils In the cover; the other is a continuous furnace, which is a constant temperature furnace. Preheating, heating, heat preservation, and cooling are carried out in different boxes. [0003] The advantage...

AI Technical Summary

Problems solved by technology

[0003] The advantages of the existing bell furnace are low equipment cost, good elongation after annealing of the workpiece, convenient maintenance, and good air tightness. The disadvantages are as follows: 1. The intermittent heating consumes more energy than the continuous heating, and the workpiece cools down The waste heat of the process is basically not effectively utilized. Due to the stacking of rolls, in order to shorten the cooling time, it is generally necessary to configure an air and water cooling cover, which needs to be matched with a circulating water pump group, cooling, and storage systems; even a special fan with a fan is added. Cooling table; 2. Lack of continuous furnace-specific workpieces. The process of hot drawing and straightening can be obtained in the furnace; cleaning, finishing, cold drawing and straightening, electrostatic oiling and other equipment cannot be randomly configured, although they can be configured separately before and after heat treatment, but Compared with the increased process and cost, and the shape of the plate is not as good as that of the continuous furnace

[0004] The advantages and disadvantages of the existing continuous furnace are partly opposite to those of the bell furnace. However, the waste heat in the cooling process is separated from the preheating section and The cooling section is connected, and the protective atmosphere in the furnace is forced to circulate between the preheating section and the cooling section through the fan to realize heat exchange; however, practice shows that the waste heat utilization rate of this method is not high. The main reasons are: 1. There will inevitably be heat loss in the air duct outside the box, and the heat loss rate is not low; 2. Basically, only the flowing protective atmosphere with a low temperature is used as the heat transfer medium, so the heat transfer efficiency is not high; 3. Cooling, The preheating is only carried out in one or two boxes respectively, and the temperature difference cannot be used in multiple gradients. Due to the high heat loss rate of the air duct outside the box, the effect of setting multiple boxes for heat exchange is not great; 4. Circulation The fan also consumes energy when it is running, and it is easy to cause leakage of the protective atmosphere; moreover, the workpiece that has just entered the cooling and preheating box from the heating insulation box is cooled too quickly in the protective atmosphere flowing from the air duct outside the box, making the non-solid The elongation required for the solution treated workpiece is not as good as that of the bell furnace

Images