The hottest frequency converter is 179m3 high in M

Application of frequency converter in 179m3 blast furnace of Miaogou Iron Mine of Tangshan Iron and steel mining company

1 introduction

two new 179m3 blast furnaces of Miaogou Iron Mine of Tangshan Iron and steel mining company have been investigated by Tangshan Weier Electronics Co., Ltd., Tangshan Iron and Steel Design Institute and Miaogou Iron Mine. All frequency converters use Emerson's td2000 series frequency converters, a total of 24. Among them, there are 12 sets of tdt0110g, 2 sets of tdt0150g, 6 sets of tdt0900g and 4 sets of tdt2000p. They are used in raw materials, sintering, blast furnaces, slag washing circulating water, cast iron machines, etc. they are introduced below

2 disc feeder

disc feeder is the first process in the raw material area of blast furnace ironmaking process. Various raw materials required by the whole blast furnace are sent to the first mixing and second mixing through different disc feeders through the conveyor belt, and then evenly sent to the sintering machine after full mixing. There are 11 sets of disc feeders in this system. Each set of disc feeder is a funnel-shaped but expensive equipment. At the bottom of the funnel is a raw disc driven by a motor, and the raw materials in the funnel are continuously sent to the conveyor belt through the rotation of the raw disc. According to the requirements of ironmaking process, various raw materials need different proportions. Different raw materials in each hopper are sent to the conveyor belt according to the required proportions through the adjustment of disc speed. The motor selected for the disc feeder is a 7.5kW variable frequency speed regulating motor, and the frequency converter is Emerson tdt0110g frequency converter. The control adopts local and centralized control, and the local speed is regulated by potentiometer

3 round roller distributor

as the name suggests, the round roller distributor is two large round rollers. The raw materials from the secondary mixing in the upper silo are sent to the trolley of the sintering machine through the round roller distributor. The speed of the round roll distributor is adjusted by the motor controlled by the frequency converter, and the speed of feeding the sintering machine trolley is controlled according to the process requirements. Because the round roll distributor sometimes needs to run at low speed for a long time, the motor adopts a 7.5kW variable-frequency motor. The frequency converter is tdt0110g frequency converter. The control adopts local and centralized control, and the local speed is adjusted by potentiometer. The main parameter settings of the schematic diagram and frequency converter are the same as those of the disc feeder (see Figure 1 and table 1)

4 sintering machine

sintering machine is to fully burn raw materials on the trolley to form sinter. The quality of sinter depends on whether the raw materials are fully burned in the trolley. The trolley needs to adjust the speed according to the thickness of the round roll distributor and the combustion in the sintering machine. The speed control accuracy is required to be high. The trolley is regulated by the motor controlled by the frequency converter. The 11kw three-phase squirrel cage asynchronous motor is selected as the motor, and the frequency converter is Emerson tdt0150g frequency converter. The control adopts machine side control, potentiometer machine side speed regulation, and the frequency converter is forward and reverse control

5 belt cooler

the sinter from the sintering machine is crushed by a single roll crusher and enters the belt cooler. The belt cooler is a long chain track, commonly known as the castor. The high-temperature sinter moves slowly on the castor. After being cooled by 6 fans, the cooled sinter enters the bunker for charging the blast furnace. The castor is regulated by the motor controlled by the frequency converter. The 11kw frequency conversion speed regulation motor is selected, and the frequency converter is Emerson tdt0150g frequency converter. The control adopts local and centralized control, and the local speed is adjusted by potentiometer. Schematic diagram and main parameter settings of frequency converter, such as disc feeder (see Figure 2 and table 2)

6 charging winch system

6.1 process requirements

the charging winch system of blast furnace is a key link in ironmaking production. Its main function is to continuously send all kinds of raw materials required for ironmaking to the blast furnace to ensure the normal needs of blast furnace ironmaking. The core of the whole charging winch system of blast furnace is the main lifting equipment of charging car. The main winding motor is a 55kW 10 pole wound asynchronous motor. First, check whether there is a resonance governor around the experimental machine by frequency conversion. Emerson tdt0900g frequency converter and corresponding braking resistance and braking unit are used. The blast furnace charging winch system has the following characteristics: the main winch motor works frequently, the load is heavy, and the starting torque is high. The hopper car requires high accuracy of position control and high reliability and safety of the system. The charging car vibrates greatly during starting and parking braking, which requires good stability of the motor. The technical scheme of the charging winch system of the iron making blast furnace is that after the charging winch system operates, the frequency converter accelerates from 0Hz to 50Hz. When it runs for a certain distance and reaches the top of the furnace, the master command (CAM) at the detection position sends a deceleration signal, and the frequency converter automatically decelerates to 20Hz for operation until the charging car reaches the top of the furnace, and then the master command (cam - interior technical manager of the technical center of Peng Zhijun Jianghuai Automobile Company) sends a stop signal, The motor is immediately braked and stopped, and the motor is equipped with an electromagnetic holding brake braking device. When it needs to stop during the whole working process, a parking command is issued, and the electromagnetic holding brake braking device works, so that the charging car can stop stably without the "trailer" sliding phenomenon

when the PC output point J1 is closed, the frequency converter accelerates from 0Hz to 50Hz in the set time of 5S. The electromagnetic holding brake control power supply JZ is powered on, the holding brake is opened, and the left hopper car runs upward at the set 50Hz frequency. When the feeder car runs to the detection point, J3 closes, and the feeder car starts to decelerate, and keeps running at a constant speed after decelerating to 20Hz. When the hopper car is about to run to the position, the limit switch is triggered to send a signal, the PC output point J1 is disconnected, and the frequency converter stops freely. When the frequency converter output drops to 2Hz, the electromagnetic holding brake control power supply JZ is powered off, the holding brake is held, and the winch motor of the hopper car is braked and stopped to complete a feeding process. When the PC output point J2 is closed under the impact force exerted by the punch, the right hopper car and the left hopper car complete the feeding at one time. QA2 and QA3 are the inching buttons of the left and right hopper cars, and QA1 is the reset button. In order to increase the reliability of the system, do the following:

(1) the capacity of the frequency converter is 90kw, which enlarges the capacity of two gears compared with the motor 55kW. Generally, there will be no overcurrent, overvoltage, overload and other phenomena, and the reliability is greatly improved

(2) the electromagnetic holding brake coil is controlled by the operation output signal Y2 of the frequency converter, which eliminates the accidents caused by accidents, such as the skip trailer or stall out of control caused by opening the holding brake. Moreover, when the output of the frequency converter reaches 2Hz, the control power supply JZ of the electromagnetic band brake is powered on to prevent the band brake from opening too early and the skip from slipping

(3) install an over limit limit switch J3 on the top of the left and right charging cars respectively. When J3 acts, it causes the external fault shutdown of the frequency converter through the multi-function terminal X2, so as to prevent the serious consequences of damaging the furnace top equipment due to the control line fault when the charging car approaches the parking point, causing the charging car not to slow down and overshoot

6.3 parameter setting

7 slag flushing circulating water pump

the process of blast furnace slag flushing is to open the slag port before the molten iron is discharged from the blast furnace. The slag is lighter than the molten iron, floats on the molten iron, and flows out of the slag port first