Control method of protective atmosphere of stainless steel cover type annealing furnace

Abstract

The invention relates to a control method of a protective atmosphere of a stainless steel cover type annealing furnace, which is characterized by sequentially comprising the following steps of: a. blowing air inside an inner cover of a furnace platform; b. replacing nitrogen inside the inner cover with hydrogen: setting the maximum discharge flow rate of an electromagnetic valve into 30 m3 / h according to process requirements; introducing the hydrogen into the inner cover to replace the nitrogen inside the inner cover according to the set flow rate for normally operation; discharging a mixed gas of the hydrogen and the nitrogen through a waste gas regulating valve and a discharge pipe, wherein when the total amount of the hydrogen reaches 22 m3 during the operation, the electromagnetic valve of hydrogen flow rate is automatically closed; c. stabilizing voltage: ensuring pressure inside the annealing furnace to be kept between 2 kPa and 6 kPa; and d. blowing the hydrogen inside the inner cover of the furnace platform after annealing is finished. The invention solves the problem that the hydrogen can not be normally introduced at a debugging stage and reduces the hydrogen consumptionof a whole annealing period, one annealing cycle period of an original process needs to consume the hydrogen about 240 m3, and one annealing cycle period of the control method needs to consume the hydrogen about 30 m3-35 m3, thus production cost is greatly saved.

Description

technical field [0001] The invention relates to the technical field of bell-type annealing units in the stainless steel industry, in particular to a method for controlling the protective atmosphere of stainless steel bell-type annealing furnaces. Background technique [0002] The protective atmosphere control process of the currently designed stainless steel full-hydrogen bell annealing furnace generally has the following steps: [0003] 1. Air purging, all the air replaced by nitrogen passes through the pneumatic valve 801. After the purging is completed, the valve is closed until the annealing is completed; [0004] 2. During the commissioning process, adjust the valve position of the SV-809 solenoid valve first. In normal operation, the maximum discharge flow rate is 30m according to the process requirements. 3 / h, its data is read from the Roots flowmeter; [0005] 3. If the process requires the discharge flow rate to be 15m 3 / h, then discharge the SV-809 solenoid va...

AI Technical Summary

Problems solved by technology

[0009] ①The problem that occurs during the operation of the equipment is that hydrogen cannot enter the inner cover due to the high atmospheric pressure in the inner cover when hydrogen is replaced by nitrogen. If the hydrogen inlet pressure is increased, the furnace pressure will rise and an alarm will appear. , by adjusting the valve position of the SV-809 solenoid valve, increase the opening of the SV-809 solenoid valve, so that hydrogen can enter the inner cover, but there will be a problem of increased hydrogen consumption

[0010] ② Due to a large amount of hydrogen emission, a large amount of heat in the inner cover is also lost, wasting energy

[0011] ③ If the protective gas is discharged by controlling the opening and closing of the electromagnetic valve SV-809 at intervals, the pressure in the furnace will also be unstable