Application of new technology and new technology in sintering machine

I. Overview

Two Handan Iron and Steel Group, Handan Iron Baosteel Co., Ltd., a large 360m ² sintering machine, two 3200m ³ blast furnace is supporting projects to meet the needs of 70% blast furnace sinter, the project covers an area of 117,600 m ^2, designed annual output of sinter 7.26 million tons, sintering machine utilization coefficient of 1.25t / m ² · h, annual operating rate of 92%, sinter grade 58.2%, sinter R2 2.0 times, Mg0 content ≥ 2.2%, sintered ore size 5 ~ 190mm, sinter The temperature is <150 ° C, the average alkalinity of the sintered ore CaO / SiO ₂ = 2.0, TFe = 58.2, the consumption of solid fuel is 55 kg per ton of sintered ore, and the sinter drum index is ≥ 77%.

The sintering machine adopts mature, practical, advanced and reliable process and equipment. The automation level is advanced and practical, and the equipment and equipment level has reached the domestic advanced level.

Second, the main process of the sintering machine

(1) After the fuel conveyed from the raw material field is stored in the fuel buffer tank, it is coarsely broken by two φ1200mm×1000mm double-light rolls, and the crude broken fuel is broken to less than 3mm by four four-roll crushers φ1200mm×1000mm. The broken fuel is delivered by the belt conveyor to the fuel compartment of the batching chamber. The fuel preparation system is shared by two sintering machines.

(2) The batching silo is arranged in a single row, each sintering machine corresponds to one series, and each series has 14 mining tanks. Mixing materials, fluxes, fuels, cold return mines and dusts are all weight-weighted. The automatic batching control is carried out by the PLC system, and an online calibration device is set up. In order to stabilize the level of the batching tank, each tank is provided with a weighing level gauge, which can continuously display the measured value. The quicklime and light burnt dolomite powder are transported to the batching tank by a sealed tanker and then pneumatically conveyed into the batching tank. The mixing material is transported from the raw material field to the batching chamber through the belt conveyor, and is discharged by the moving belt into 5 ore tanks of each series.

(3) Using a two-stage mixing process, the mixer is arranged in the open air, the primary mixer is φ3.8m×15m, the secondary mixer is φ4.4m×21m, the mixer is added with hot water, and the mixing is sprayed with atomized water by rotating nozzle. The second mixing uses a double-drain rotary nozzle to spray atomized water to meet the requirements of mixing and granulation. The water added to the mixture is automatically controlled. At the same time, in order to increase the temperature of the mixture, steam is added to the mixture to preheat the mixture.

(4) There is a bottoming device, and the bottom material has a granularity of 8 to 13 mm, which is evenly distributed on the trolley by the swinging funnel. The mixture fabric is uniformly distributed on the sintering trolley by a cloth device consisting of a round roller feeder and nine rollers. Pure coal ignition fuel coke oven gas, negative pressure ventilation sintering.

(5) The sintering machine trolley is 4m wide, the effective length is 90m, the trolley block is 700mm high, and the double side bellows and the asymmetric flue are provided. The sintered cake was crushed by a single roll crusher and directly entered into a 415 m ² blast ring cooler.

(6) The whole process of each sintering machine is double series, one series is produced, and the other series is spare. The sinter ore from the ring cooler is uniformly fed through the plate type ore feeder, and then sent to the screening room through the belt conveyor. After three times of screening, the finished sinter of +13mm and -13mm two grades are output to the blast furnace to realize the sinter. The grade is put into the furnace. The sinter from the sampling chamber goes directly to the blast furnace loading system, and can also be transported to the finished mine bin through two other belt conveyors to regulate the sintering and blast furnace production, and realize the two sintering machines to the two blast furnaces. supply.

(7) Sintering machine, ring cooling machine, single roll crusher, mixer, elliptical and other thick vibrating screens and other equipment adopt advanced technology and set centralized intelligent lubrication system. The main drive unit of the sintering machine adopts multi-flexible transmission, the head and tail star wheels adopt new tooth plate tooth shape, the trolley body and the block plate adopt ductile iron, the purlins and heat insulation parts adopt high chromium cast iron, and the bellows disc valve is set to automatically adjust. Type and opening and closing type, the head star wheel adopts imported bearings. The ring cooler is driven by a double drive and a friction wheel. The trolley seal uses two cone seals and five cooling fans. Single roll crusher water-cooled shaft, the surface of each grate plate and a hammer with a welding temperature, wear resistant alloy materials, imported spindle bearings, using fixed horizontal axis and the torque coupling opening Hardened reducer plus Gear transmission. The mixer is equipped with a micro-motion device, which adopts a forged rolling ring, and the supporting wheel and the retaining wheel bearing are imported. The elliptical equal-thickness vibrating screen adopts the advanced screening principle and the excitation principle. The processing capacity per unit area is large, the screening efficiency is high, and the whole machine has a long service life.

(8) The “Three Electricity Integration” system digests and absorbs large-scale sintering control technology at home and abroad, sets up a complete process parameter detection control, and adopts an EIC computer control system with advanced technology, stable performance and reliable quality. The automatic control system is divided into L1 basic automation control and L2 process automation control. The L2 process automatic control adopts the sintering monitoring system of voestalloy Lod Loki Company, and reaches the domestic leading and international advanced level in the control level.

(9) Environmental dust removal set 7 high-efficiency wide-pitch four-field electric precipitators and one bag filter, including two 60m ² batch electric precipitators, two 180m ² tail electric precipitators, two sets of 70m ² whole grain electric Dust collector, a 90m ² finished electrostatic precipitator, to ensure that the dust content of the dust removal outlet is less than 50mg/m ³ , and the dust content of the bag dust removal outlet is less than 30mg/m ³ . The dust removal system adopts the advanced dust removal pipeline resistance balancer. The upper part of the mine tank adopts the mobile unloading vehicle dust removal air volume switching device. The wearable part of the dust removal pipeline system adopts wear-resistant technology, and different dust resistance pipelines for different natures are used. Grinding measures to extend the service life of the dust removal pipeline and reduce the maintenance workload of the dust removal pipeline. The operation of the dust removal system is realized by the PLC system to achieve centralized automatic control.

(10) The dust is pneumatically conveyed, and the dust collected by the tail, the ingredients, the finished product, and the whole electrostatic precipitator is transported to the dust chamber of the batching chamber by the positive pressure of the dust pump and the dust conveying pipeline of each dust collector; The dust collected by the head electrostatic precipitator collects the dust of each electric field into the dust intermediate bin by the scraper conveyor, and then uses the positive pressure pneumatic force to deliver to the dust chamber of the batching room.

(11) In terms of environmental protection, SO ₂ pollution prevention and control uses low-sulfur raw fuel, and a 150 m high main chimney is set for high-altitude discharge, and a desulfurization flue is set at the same time. The two sintering machines are recycled for production water, and there is no production wastewater discharge during normal production. The noise pollution prevention device is equipped with a muffler and a closed sound insulation measure. The main exhaust fan and the bag type dust removal system fan are enclosed and installed in the fan room, and the main exhaust fan casing is provided with soundproof material. A muffler is provided at the main exhaust fan, the ring cooler cooling fan, the ignition furnace combustion air blower, and the dust collector fan outlet.

(12) The energy consumption of the sintering process is designed to be 68kg/t sinter, the gas consumption is 0.08GJ/t, the solid fuel consumption is 55kg/t, and the power consumption is 36kw·h/t.

Third, the adoption of new technologies and energy-saving measures

(1) Using the weighing type mineral tank, digesting and utilizing the Luxembourg batching scale technology, centralized automatic batching to stabilize the mix ratio and composition requirements of the mixture, which is conducive to improving the yield and quality of the sinter.

(2) Using two-stage mixing, using quicklime granulation and thick material layer sintering, improving the gas permeability of the mixture and reducing the consumption of solid fuel.

(3) In order to protect the trolleys of the trolleys, reduce the dustiness of the flue gas, and make the mixture burn well and burn through, the bottoming process is adopted.

(4) The ignition equipment adopts double oblique ignition holding furnace (GJH-360 type), and the double oblique ignition holding furnace is the patented product of Changsha Metallurgical Design and Research Institute (patent number: ZL99233370.9). The double-inclined ignition holding furnace has the following characteristics: the strip flame formed by the double oblique cross burner directly ignites the mixed material surface, the furnace height is moderate, the ignition energy is low, the material surface ignition quality is good, the FeO content is low, the sinter The yield is high; due to the large fluctuation of the heating value of the high-focus mixed gas, it is difficult to set a proper proportion of air gas, which often causes the proportion of air gas to be inappropriate, and the gas combustion is incomplete, resulting in high gas consumption and waste of energy. If blast furnace gas is used, Coke oven gas enters the ternary nozzle mixed burner of the ignition furnace (patent number: ZL03227464.5), which can solve the above problems. The computer can automatically adjust the air and gas ratio to ensure the full combustion of the gas; use the insulation section of the ignition holding furnace To preheat the combustion air (the air temperature can be preheated to 200 ° C), saving gas consumption, thereby reducing energy consumption; using on-site casting type, good insulation effect, long service life (more than four years); at the same time, the ignition furnace is easy to operate. Safe and reliable.

(5) The ring cooling machine fan has reasonable configuration, compact structure and smooth wind direction. The fan is equipped with a muffler and an electric regulating gate, which can realize automatic adjustment of the opening degree of 0 to 90 degrees, so as to control the air volume and pressure, and realize the dust-free cooling of the material surface.

(6) The temperature of the exhaust gas in the high temperature section of the ring cooler is relatively high, about 250-300 °C. The heat recovery is converted into steam by a heat pipe type waste heat recovery device to improve the environment around the ring cooler and reduce dust pollution. A double-layer sealing mechanism is arranged in the sealing cover of the waste heat recovery section to effectively prevent the loss of hot air flow and improve the waste heat recovery effect; the generated steam (12-14t/h. stage, pressure 1.3MPa) is incorporated into the steam main net to save energy.

(7) The main exhaust system consists of a bellows, a gas collection pipe, a head electrostatic precipitator, a main exhaust fan and a chimney. The sintering machine exhaust system has a reasonable structure, low air leakage rate, and an efficient fan rotor. The new sintering machine is a double side bellows and a double exhaust pipe. The end of the bellows of the sintering machine is provided with a full metal structure block type end seal (this structure is combined with the patent of Handan Iron and Steel Co., Ltd.), and the head is provided with a section, the ignition bellows is provided with a section of 1.5m (becomes a draft section), and the tail section is provided with two sections. The side of the trolley and the bellows are sealed by the slats and fixed slides, and the special sealing measures are designed for the bellows frame beam and the side sill of the bellows to ensure that the air leakage rate is less than 35%; the bellows is double-sided suction type to ensure uniform ventilation on the trolley. And design a special anti-leakage structure, the bellows valve is set to automatic adjustment type and open and close type to achieve air volume and negative pressure control, sintering end point control and automatic ash, automatic reset. The machine head adopts high-efficiency electric precipitator to prevent the main exhaust fan blade from being worn and better protect the environment; the dust settled in the electrostatic precipitator of the machine head is fed into the scraper transporter through the double-layer unloading valve, and then added to the returning belt conveyor. Into the batching room, the bulk material on the returning lane of the sintering trolley and the dust settled in the exhaust pipe are collected by the belt conveyor and then enter the finished belt. Two 280 m ² horizontal three-field electric precipitators are installed in each sintering machine head, and the dust removal efficiency is 99%.

Each sintering machine is equipped with two SJ18000 sintering exhaust fans, the negative pressure is 17000Pa, the air volume is 18000m ³ /min (working condition), the motor is 6500kW, the fan rotor is made by the company Howden Company, and the water resistance is started. After the sintering flue gas passes through the system, the exhausted flue gas has a dust concentration of <50 mg/m ³ .

(8) Environmental protection Strictly implement national and local regulations to prevent and reduce environmental pollution caused by dust, exhaust gas, noise, etc.; dust content of electric dust removal outlet is less than 50mg/m ³ , dust content of bag dust removal outlet is less than 30mg/m ³ , The post dust concentration is less than 10mg/m ³ . Take the following technical measures:

1. Take necessary dust source sealing measures for dust-producing equipment and dust-producing points, set up an air hood or a closed cover, and adopt mechanical ventilation to ensure negative pressure inside the cover to control dust escape.

2. Efficient and wide-pitch electrostatic precipitator and bag filter are the main purification equipments to ensure that the exhaust emission concentration is lower than the nationally allowed emission standards and meet the emission standards allowed by the project.

3. According to the process of production and work system, the dust removal system is divided into dust removal systems. The large centralized dust removal system is used to facilitate management and maintenance while ensuring long-term stable operation of the system.

4. The ash conveying equipment in the lower part of the dust removal equipment adopts a scraper conveyor with good sealing performance, wear resistance and low failure rate, which is suitable for conveying sintered dust.

5. The dust collected by the dust removal equipment is humidified according to the specific conditions and then discharged to the process belt machine to reduce secondary pollution.

6. The wear-resistant part of the dust-removing pipe system is wear-resistant. Different dust-proof pipes for different dusts are used. The high-temperature flue gas pipeline at the tail end adopts wear-resistant ceramic sheets, and the patented wear-resisting patent technology is adopted in the whole-grain dust-removing pipeline to extend the service life of the dust-removing pipeline and reduce the maintenance workload of the dust-removing pipeline.

7. The dust removal system adopts the advanced patented technology of dust balance pipeline resistance balance, which effectively controls the imbalance of the resistance balance of each branch pipe of the system to ensure the reliable operation of the dust removal system.

8. The operation of the dust removal system is automatically controlled by the PLC system.

9. The wall thickness of the dust removal pipe is designed by multiplying the current specification by 1.5.

10. The use of quicklime granulation and thick material layer sintering to reduce the dust content in the flue gas of the machine head.

(9) The system selects SG10 series low-loss transformer to make its load rate in the best energy-saving operation state.

(10) Adopting process automatic detection and control to keep production in the optimal state set.

(11) The production water is completely recycled, and the whole plant has no production sewage discharge.

In summary, the 360m2 sintering machine process equipment, automatic control, environmental protection and energy saving of Handan Iron and Steel Group Co., Ltd. have reached the domestic advanced level.

Angle Valves

Globe Valves and angle valves are designed for throttling or regulating flow in commercial and industrial applications. Bronze, cast iron, or cast ductile iron materials. Threaded, flanged, or solder end connections.