CN218723100U

CN218723100U - Hot air internal circulation type iron ore sintering system

Info

Publication number: CN218723100U
Application number: CN202222714476.4U
Authority: CN
Inventors: 徐守国; 于海波; 唐文俊
Original assignee: Nanjing Huadian Energy Saving And Environmental Protection Co ltd
Current assignee: Nanjing Huadian Energy Saving And Environmental Protection Co ltd
Priority date: 2022-10-11
Filing date: 2022-10-14
Publication date: 2023-03-24
Anticipated expiration: 2032-10-14
Also published as: CN115540605A

Abstract

The utility model provides a hot-blast inner loop formula iron ore sintering system, including sintering machine, gas heater, air heat exchanger, cold water pipe and hot-water line, the sintering machine includes big flue, and gas heater locates the inside outlet flue of big flue, and gas heater's water inlet passes through the cold water pipe to be connected with air heat exchanger's delivery port, and gas heater's delivery port passes through the hot-water line to be connected with air heat exchanger's water inlet, is equipped with the circulating pump on the pipeline of cold water pipe, and air heat exchanger locates the sintering machine top, is located in the middle of sintering machine aircraft nose and the tail. Compared with the prior art, the system utilizes the waste heat of the waste gas of the sintering machine, is convenient to adjust, low in energy consumption, good in sintering effect and capable of saving cost, and the water flow adjusting valve is arranged on the cold water pipeline, so that the temperature of water entering the flue gas heat exchanger is guaranteed, and dew point corrosion is prevented.

Description

Hot air internal circulation type iron ore sintering system

Technical Field

The utility model belongs to the technical field of metallurgical hot air sintering machine, in particular to hot air internal circulation formula iron ore sintering system.

Background

Hot gas sintering (hot gas sintering) refers to an iron ore sintering process in which a sintering machine is ignited and then sintered with hot air or hot exhaust gas at 300 to 1000 ℃. The conventional sintering process relies on air at room temperature for sintering after sintering ignition. Because of the automatic heat storage function in the sintering process, the sintering temperature of the upper part of the material layer is low, the sintering temperature of the lower part is high, so that the upper part is often insufficiently sintered, the liquid phase amount is insufficient, the strength of the obtained sintered ore is low, a plurality of return ores are formed, and the lower part is excessively fused due to the overhigh sintering temperature, so that the reducibility of the sintered ore is deteriorated. The ideal sintering regime is to make the sintering temperature uniform along the height of the bed. The hot air sintering is to use hot air to continuously provide heat to the material layer after ignition so as to supplement the heat of the upper layer, so that the sintering temperatures of the upper material layer and the lower material layer are uniform.

The temperature, heating time and oxygen content in hot air have great influence on the sintering effect of hot air. The appropriate hot blast temperature depends on the nature of the ore, the supply and price of gas and solid fuel. The adoption of higher air temperature can save more solid fuel, reduce the FeO content in the sintering ore and improve the reducibility, but influences the yield of the sintering machine; the purpose can not be achieved by adopting the low wind temperature, and the effect is better at 900 ℃.

The reasonable heating time is based on the principle that enough heat can be ensured on the upper layer, and the heat on the lower part is not excessive. The heating time is too long, the heat supply is too much, although the solid fuel can be reduced, the gas consumption is increased, the total heat consumption is increased, the material layer temperature is increased, the material layer resistance is increased, and the yield is reduced. Generally, the heating time is preferably 4-5 min (i.e. one third of the whole sintering time), otherwise, the yield is greatly influenced. The hot exhaust gas has an oxygen content of not less than 10.5%, otherwise the solid fuel consumption increases and the hot exhaust gas contains H ₂ O and CO ₂ The amount should not be too high.

There are 3 ways to obtain a source of hot air:

the 1 st is to use a copy hot blast stove or other form of heat exchanger to generate hot blast. The method can adjust the temperature of the hot air, ensure that the surface temperature of the trolley is easy to achieve uniform distribution, has sufficient oxygen content in the hot air, is beneficial to improving the yield and the quality of the sinter, but has high capital investment and high operating cost.

The 2 nd method is to install a heater or holding furnace behind the igniter and use the high-temperature hot exhaust gas after the gas combustion. Its advantages are simple equipment, easy operation, high safety and reliability, and high effect.

The 3 rd way is to use the sinter tail or cooler hot exhaust gas. The proposal does not excessively increase equipment, has simple method, but has lower hot air temperature and lower effect than the two proposals.

The hot air sintering increases the sintering temperature of the upper part of the material layer, increases the liquid phase amount, reduces the liquid phase viscosity, is beneficial to fully crystallizing minerals, and reduces the content of glass phase, thereby improving the overall finished product rate of sintering and the strength of sintered ore. Furthermore, the method is simple. The hot air replaces cold air, so that the temperature difference between the pumped air and the hot sintering layer is reduced, the cooling speed is reduced, the thermal stress is reduced, and the strength of the sintered ore is improved.

The hot air sintering can reduce the consumption of solid fuel, reduce the over-melting and reduce FeO, thereby improving the reducibility of the sintering ore. When hot air at 1000 ℃ is used for sintering, the solid fuel can be saved by 20-30%, the total heat consumption is reduced by 10-13%, the performance of sintered ore metallurgy is improved, and the powder amount is greatly reduced. However, hot air sintering causes a decrease in sintering speed, and thus the yield is decreased under the condition that the permeability of the material layer is not improved.

SUMMERY OF THE UTILITY MODEL

Utility model purpose: in order to solve the defects of the prior art, the utility model provides a heated air circulation formula iron ore sintering system, this system have utilized the waste heat of sintering machine waste gas, and it is convenient to adjust, and the energy consumption is low, practices thrift the cost, and sintering effect is good.

The technical scheme is as follows: the utility model provides a hot-blast inner loop formula iron ore sintering system, including sintering machine, gas heater, air heat exchanger, cold water pipe and hot-water line, the sintering machine includes big flue, and gas heater locates the inside outlet flue of big flue, and gas heater's water inlet passes through the cold water pipe to be connected with air heat exchanger's delivery port, and gas heater's delivery port passes through the hot-water line to be connected with air heat exchanger's water inlet, is equipped with the circulating pump on the pipeline of cold water pipe, and air heat exchanger locates the sintering machine top, is located in the middle of sintering machine aircraft nose and the tail.

As preferred or specific embodiments:

the sintering machine further comprises an air box and an ash discharge hopper, wherein the air box is communicated with the large flue, the air box is located above the large flue, and the ash discharge hopper is located below the large flue.

The air heat exchanger comprises a heat exchange tube, a water outlet of the heat exchange tube is connected with a cold water tube, and a water inlet of the heat exchange tube is connected with a hot water tube.

An adjusting valve is connected between the cold water pipe and the hot water pipe; the regulating valve regulates the water flow according to the temperature value displayed by the thermometer on the cold water pipe and the inlet water temperature of the controlled flue gas heat exchanger.

Has the advantages that: compared with the prior art, the utility model discloses the device has following advantage:

(1) The waste gas is cooled by utilizing the waste heat of the sintering machine waste gas, so that the method is suitable for rear desulfurization and denitration, the links of spraying water to cool the waste gas in the original process are reduced, and water resources are saved;

(2) The sintering combustion-supporting air is heated, the oxygen content is sufficient, the improvement of the yield and the quality of the sintering ore is facilitated, the medium circulating in the circulating conveying pipe is water, the adjustment is convenient, and the capital investment and the operation cost are low;

(3) The temperature uniformity in the material layer of the sinter is improved, and the solid fuel quantity is saved;

(4) The medium of the circulating pump is water, and compared with hot air delivery after air is directly heated, the circulating pump is convenient to adjust and low in energy consumption.

Drawings

FIG. 1 is a schematic structural view of a heated air circulation type iron ore sintering system according to the present invention.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

Examples

The utility model provides a heated air circulation formula iron ore sintering system, as shown in figure 1, including sintering machine 1, gas heater 2, air heat exchanger 3, cold water pipe 4 and hot-water line 5, sintering machine 1 includes big flue 11, and bellows 12 and ash discharge hopper 13 with big flue 11 UNICOM, bellows are located big flue 11 top, ash discharge hopper 13 is located big flue 11 below, gas heater 2 locates the inside outlet flue of big flue 11, the water inlet of gas heater 2 passes through cold water pipe 4 and is connected with the delivery port of air heat exchanger 3, the delivery port of gas heater 2 passes through hot-water line 5 and is connected with the water inlet of air heat exchanger 3, be equipped with circulating pump 6 on the pipeline of cold water pipe 4, air heat exchanger 3 locates sintering machine 1 top, be located in the middle of sintering machine 1 aircraft nose and tail.

The sintering ore on the sintering machine 1 is open, a preheating ignition section is usually arranged above the machine head part, and hot air enters a material layer; the tail part of the machine is close to the circular cooler, so that hot air after mineral aggregate cooling of the circular cooler can be introduced; the middle part is completely open, so the temperature distribution of the bed is: the material surface temperature of the front section is higher due to the ignition section, then the material surface begins to cool due to the entering of cold air, and the tail is cold and hot air with a ring. The temperature of the charge level is also higher. Therefore, in the system, the air heat exchanger 3 is arranged above the sintering machine 1 and between the head and the tail of the sintering machine 1, so that the temperature of the charge level in the middle section can be increased, the temperature change range in the charge level is reduced, and the quality of sintered ores is improved.

The air heat exchanger 3 comprises a heat exchange tube, the water outlet of the heat exchange tube is connected with a cold water tube 4, and the water inlet of the heat exchange tube is connected with a hot water tube 5.

An adjusting valve 7 is connected between the cold water pipe 4 and the hot water pipe 5, and the adjusting valve 7 adjusts the water flow according to the temperature value displayed by a thermometer 8 on the cold water pipe 4 and the inlet water temperature of the controlled flue gas heat exchanger 2. The design can ensure the water temperature of the flue gas heat exchanger 2 and prevent dew point corrosion.

The working principle and the method of the hot air circulation type iron ore sintering system are as follows:

the hot air circulation type iron ore sintering system utilizes waste gas at the temperature of-200 ℃ in a sintering large flue 11, a flue gas heat exchanger 2 is arranged in the large flue 11, circulating water is heated to the temperature of-180 ℃ from the temperature of-130 ℃, and the temperature of the waste gas is reduced to-30 ℃. Heated circulating water enters the air heat exchanger 3 through the hot water pipe 5, cold air above the outside of the air heat exchanger 3 absorbs heat of hot water in the air heat exchanger 3, hot air is formed after temperature rise, and the hot air enters the mineral aggregate layer 14 in the middle section downwards through a gap of a pipeline to carry out sintering combustion supporting. Meanwhile, the temperature of the hot water in the air heat exchanger 3 is reduced to 130 ℃, the hot water enters the flue gas heat exchanger 2 arranged in the large flue under the driving of the circulating pump 6, the heat of the waste gas is continuously absorbed, and the circulation is continuously carried out.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a hot-blast internal circulation formula iron ore sintering system, its characterized in that, includes sintering machine (1), gas heater (2), air heat exchanger (3), cold water pipe (4) and hot-water line (5), sintering machine (1) is including big flue (11), and the inside outlet flue of big flue (11) is located in gas heater (2), and the water inlet of gas heater (2) passes through the cold water pipe (4) and is connected with the delivery port of air heat exchanger (3), and the delivery port of gas heater (2) passes through the hot-water line (5) and is connected with the water inlet of air heat exchanger (3), is equipped with circulating pump (6) on the pipeline of cold water pipe (4), and sintering machine (1) top is located in the middle of sintering machine (1) aircraft nose and tail in air heat exchanger (3).

2. A hot air internal circulation type iron ore sintering system according to claim 1, wherein the sintering machine (1) further comprises an air box (12) and an ash discharge hopper (13) communicated with the large flue (11), the air box is located above the large flue (11), and the ash discharge hopper (13) is located below the large flue (11).

3. A hot air internal circulation type iron ore sintering system according to claim 1, wherein the air heat exchanger (3) comprises a heat exchange pipe, the water outlet of which is connected with a cold water pipe (4) and the water inlet of which is connected with a hot water pipe (5).

4. A hot blast internal circulation type iron ore sintering system according to claim 1, wherein a regulating valve (7) is further connected between the cold water pipe (4) and the hot water pipe (5).