SU1296591A1 - Method for diverting converter gases - Google Patents

Abstract

The invention relates to the field of ferrous metallurgy, and more specifically to methods for removing converter gases with full post-combustion of carbon monoxide. The purpose of the invention is to increase the efficiency of the process of removal of converter gases and reduce emissions of nitrogen oxides into the atmosphere. During the purge, the converter gases are gradually burned down and cooled in the cooling boiler. At the first stage, the coefficient of air flow going to the afterburning of CO is chosen in the range from 0.4 and coolant gases to 700–1000 0. In the second stage, at 0.7 oi.0.4, the gases are afterburned and cooled to 700- 1000 C. At the third stage, the converter gases are completely after-burning with 1.1 g, 7 and then cooled before being fed to the gas cleaning to a temperature of 150-400 C. The invention provides for the formation in each zone of approximately the same volume of dry gas. and uniform heat load in the zones, which allows efficient transfer of converter gases flues with a minimum size in cross section. Since in the second and third zones the theoretical burning temperature is reduced, the harmful emissions of nitrogen oxides into the atmosphere decrease by a factor of 3. 1 ill., 1 tab. with S (L to with and JV CD

Description

The invention relates to the field of ferrous metallurgy and can be used in oxygen converters with the removal of gases with complete afterburning of carbon monoxide in any method of oxygen purging of the converter - upper, lower or combined, as well as in any metallurgical production with a periodic cycle of operation.

The aim of the invention is to increase the efficiency of the process of removal of converter gases and reduce emissions of nitrogen oxides into the atmosphere.

The removal of converter gases is carried out with the stage-by-stage afterburning of carbon monoxide and their cooling.

At the first stage, the afterburning process with an air flow rate equal to oi 6 (3.4, with gas cooling to a temperature of 700-1000 ° C) is carried out. At the second stage of afterburning, it is about 0.7 ° C, and the gases are also cooled to 700-1000 ° C. In the third stage, with 1.1 & (), 7, the complete CO afterburning occurs in the converted gases, after which the products

.

Since the formation of nitrogen oxides during the afterburning of converter gases. is a purely thermal npoi eccoM with the | |:

K, +0,

2NO.

this reaction is reversible and shifts to the right with increasing combustion temperature

Thus, at a combustion temperature up to tOOO C, nitrogen oxides contain 0.2–0.3% of the volume of dm gases at up to –O, 8–1.0%; before - about 3.0%.

Taking into account that, in the known methods, the combustion temperature is within 1900-2300 s, nitric oxide is contained within 1%, while with stepwise afterburning, nitrogen oxide is contained within

5 10

 five

20 5

the combustion is cooled to 150-400 ° C and fed to the gas cleaning system and then emitted through the stack to the atmosphere.

The boundary values of the described parameters of the air consumption coefficients ensure the possibility of uniform afterburning over the zones of the total volume of carbon monoxide coming from the converter and the formation in each zone of approximately the same volume of flue gases and heat load. This makes it possible to select a uniform cross-section of the design of the vapor path with a minimum cross-sectional size. Cooling the flue gases in each zone to 700 ° C makes it possible to gradually reduce the physical volumes of the flue gases in each zone, while the temperature of 700 ° C is necessitated by the need for reliable subsequent afterburning of the flue gases in each zone without additional combustion of fuel (see table).

The table presents data on the volume of products of combustion of converter gas by zones.

five

0

five

0.3%, i.e. decreases by 3 times, since in the second afterburning zone the combustion temperature decreases to, and in the third to (see table).

The method is implemented using a device.

The drawing shows the gas tract of the convertef, general view.

The gas outlet of the converter tract consists of cooler 2 with drum 3 and convective heat exchange tubes 4-7 installed in converter 1 and located in cooling walls 2, regenerative chambers 8-11 with nozzles, chambers 12 and 13 afterburning, adjusting device t4 and 15 air leaks, additional evaporative surfaces 16, gas cleaning 17, smoke exhauster 18, chimney

19 and the device 20 for adjusting the gap between the converter and the cooler 2. The cooler 2 has a lower after-burning zone 21, an intermediate after-burning zone 22 and a full-after-burning zone 23 and subsequent cooling.

During purging, the converter gases enter the lower zone 21 of the post-cooling, where, through the device

When adjusting the gap, air is sucked in from its flow rate from 6 0.4 and then the gases are cooled by heat exchange pipes 4 and in regenerative nozzles of chamber 8 to 700 ° C.

In the intermediate zone 22 in the afterburning chamber 12, using the device 14 for adjusting the inflow of air, the converter gases are burned from 0.7 to 0.4 and cooled down to 700–1000 ° C in heat exchange tubes 5 and the nozzles of the regeneration chamber 9.

In the zone 23, a full carbon monoxide of 1.5 about 1.1 0.7 occurs, air leaks are controlled by the device 15. The subsequent cooling of smoke gases up to 700–1000 ° C occurs in the heat exchange tubes 6 and 7 and the nozzles of the regenerative chambers 10 and 11 Next, the flue gases are cooled in additional evaporative surfaces 16 to 150-400 ° C, then they are fed to the gas cleaning 17 and the smoke exhauster 18 is fed to 35 chimney. Steam is produced in the drum 3. In the interproductive period, the adjustable gaps 14 and 15 of air leaks are closed, and through nitrogen devices into the atmosphere, which allows the use of a dry flue gas cleaning method.

Primer p. When flushing the converter with an intensity of up to 500 m / min of oxygen, the amount of converter gases with a CO content up to 80% is 66,000 nm / h.

Given the afterburner on the proposed JO method in the first zone at 0 ,. About the physical volume of gases in the afterburning zone will reach a temperature of 2000 ° C.

With

cooling gases in the cooling zone to 800 ° C; physical volume will be 438.6-10 m / h at 800 ° C.

When afterburning of converter gases in the second afterburning zone of cooling from ° C 0.5 to the remaining volume of CO, which corresponds to L 0.7 to the total volume, the physical volume of gases will be 96 EO m / h at. . When cooled to a physical volume of gases will be 585 10 m / h.

When afterburning of converter gases in the third afterburning zone of cooling with a volume of about 1.05, the temperature of the gases is 1260 ° C, the physical volume of the gases will be 1020; 10 m / h with a temperature of 1260 s, with subsequent cooling to 200 ° C before gas cleaning, the volume of gases will be 310-10.

As can be seen from the example, while maintaining a constant gas velocity, the cross-section of the afterburning-cooling zones is reduced by 1.5 times. At the same time, the stepwise afterburning - cooling process reduces the temperature of the gases in each zone of the mountain to regulate the gap 20 between 40 and 40, which in turn is caused by the converter and the chiller air leaks, which is heated in the regenerative nozzles due to the heat of the exhaust converter gases in the period Purging, moreover, the passage along the path, the air is heated in the regenerative cells of chambers 8-1 and at the same time gives off its heat to the evaporating surfaces and the final cooling of the air occurs in additionally evaporating surfaces 16. Thus, the steam generation occurs in the purge period of the converter, and in

interproductive using

natural and chemical heat of converter gases with the alignment of the steam recovery process, reducing emissions

15

20

25 30 35 965914

nitrogen oxides into the atmosphere, which allows the use of a dry flue gas cleaning method.

Primer p. When flushing the converter with an intensity of up to 500 m / min of oxygen, the amount of converter gases with a CO content up to 80% is 66,000 nm / h.

Given the afterburner on the proposed JO method in the first zone at 0 ,. About the physical volume of gases in the afterburning zone will reach a temperature of 2000 ° C.

With

cooling gases in the cooling zone to 800 ° C; physical volume will be 438.6-10 m / h at 800 ° C.

When afterburning of converter gases in the second afterburning zone of cooling from ° C 0.5 to the remaining volume of CO, which corresponds to L 0.7 to the total volume, the physical volume of gases will be 96 EO m / h at. . When cooled to a physical volume of gases will be 585 10 m / h.

When afterburning of converter gases in the third afterburning zone of cooling with a volume of about 1.05, the temperature of the gases is 1260 ° C, the physical volume of the gases will be 1020; 10 m / h with a temperature of 1260 s, with subsequent cooling to 200 ° C before gas cleaning, the volume of gases will be 310-10.

As can be seen from the example, while maintaining a constant gas velocity, the cross-section of the afterburning-cooling zones is reduced by 1.5 times. In this case, the stepwise afterburning - cooling process ensures a decrease in the temperature of the gases in each zone, a significant reduction in the formation of nitrogen oxides grieves.

Claims (1)

Invention Formula produced in three The method of removal of converter gases, including their removal with carbon monoxide afterburning and cooling in the boiler, cleaning and exhaust of the combustion products into the atmosphere, characterized in that, in order to increase the efficiency of the process of exhaust of converter gases and reduce emissions of nitrogen oxides into the atmosphere, afterburning and cooling of converter gases stage, and on In the first stage, the process of afterburning of carbon monoxide with the coefficient of air flow rate i i 0.4 is carried out and the gases are cooled to 512965916 temperatures of 700-1000 ° С, after the second it is burned with 1.1 i о, 0.7 with the next stage and the afterburning process is carried out with gas cooling of the combustion products 0,7, 4 and cool to temperature before gas cleaning to a temperature ry 700-1000 C, at the last stage 150-400 C. Editor K.Volo.shchuk Compiled by L.Sharapova Tehred M.Hodanich Order 719/29 Circulation 550, Subscription VNISHI of the USSR State Committee for Inventions and Discovery 113035, Moscow, Zh-35, 4/5 Rausska nab. Production and printing company, Uzhgorod, st. Project, 4 Proofreader G. Reshetnik