tony steel group steel sinks hang two steelmaking furnace, each furnace configuration of a dust blower (motor power 800kw), eaf dust blower amount of wind needed to accommodate six kinds eaf process requirements, in order to improve the efficiency of the fan, the eaf dust blower frequency control is required, the use of high-voltage inverter dust blower hunan branch electric co., ltd. of cshf-1000/10 drive, and in 2007 26 february debugging put into operation.
dust blower process requirements:
eaf in the normal smelting process, a smelting cycle is divided into the following time periods: ① molten iron plus 3 minutes; ② charging three minutes; ③ power supply 21 minutes; ④ supply oxygen 30 minutes; ⑤ and other like five minutes; ⑥ tapping five minutes; ⑦ blocking eye three minutes, a total of about 70 minutes, which ①②⑤⑥⑦ five time less soot, dust blower running at low speed, low speed running time of 19 minutes, and 27% of the total smelting cycle. consider themselves fans of acceleration and deceleration, the proportion of low-speed running time is calculated as 20%. consider equipment maintenance, annual operating time is calculated as 300 days.
a1-a2 to canadian iron and charging time (low speed);
a3-a4 for the power supply and the oxygen smelting time (speed);
a5-a6 of the like kind, tapping, plugging eye time (low speed);
a2 power transmission for the acquisition of electric furnace production site and the oxygen signal begins to rise from low speed to high speed
a4 for the acquisition of electric furnace production site stop transmission and stop the oxygen signal begins to decelerate from a high to a low deceleration point.
to adapt to changes in production eaf dust blower for low speeds tentative need five kinds of air flow to accommodate the eaf process requirements.
a to b as the first segment of the low-speed low-speed range (lowest speed), b to p for the low-speed range fifth paragraph (fastest) low, q to the first segment of low r low speed (minimum speed);
b to d for the second low-speed segments, wherein b to c for the fan speed rise time;
d to f for the third low-speed segments, wherein d to e for the fan speed rise time;
f to h is the fourth low-speed range, where f to g for the fan speed rise time;
h to j as the fifth low-speed range in which h to i for the fan speed rise time;
when the fan speed can rise to cross either increases the speed point;
j point the fan begins to decelerate;
j to l of the fifth low-speed segment to the fourth low-speed segments, wherein j to k for the fan deceleration time;
l to n as the fourth low-speed segment to the third low-speed range, where l and m for the fan deceleration time;
n to p for the third low-speed low-speed segment to the second segment, wherein n to o for the fan deceleration time;
p to r as the first low-speed range in which p to q for the fan deceleration time;
q r is the first segment to the low-speed (lowest speed) low-speed segment.
pui hang steel sinks steel group steelworks using electric furnace dust blower hunan branch electric co., ltd. of cshf-1000/10 inverter speed control, the processing frequency bypass switchgear, inverter direct high - high fashion voltage source, the inverter main performance indicators are as follows: inverter capacity 1000kva, rated output current of 60a, the input frequency 45hz to 55hz, the rated input voltage 10000v, allowable voltage fluctuation ± 10%, input power factor ≥0.96 (greater than 20% load), the output frequency range by the five-speed, within 0hz to 50hz range adjustment (ie: speed range from 0 to 100%), inverter efficiency ≥98% (excluding input transformer), the output frequency resolution 0.01hz, variable speed, 120% overload for one minute, 150% protection immediately. the acceleration time is set according to process requirements, process requirements can be asked to set the time of deceleration.