RU1812213C - Gas exhaust tract of oxygen converter with gas exhaust without afterburning - Google Patents

Abstract

Usage: in the field of metallurgy, in particular in energy technology systems of converter steel production. SUMMARY OF THE INVENTION: The exhaust gas path of an oxygen converter with an exhaust gas without afterburning comprises a radial cooler, a wet gas scrubber, a supercharger, a afterburner, and a bypass branch connected to the radiation cooler box and equipped with a furnace to heat the scrap with a burner and gates before and after. The inclusion of a self-contained fuel-free superheater, a three-way control valve, a fluidized bed gasifier for gasification of industrial products, dry gas cleaning and a converter and generator gas mixer in the bypass branch is new. A gas holder and a mixed gas bypass gas pipeline are included in the path after the supercharger. 1 ill.

Description

The invention relates to the field of metallurgy and can be used in energy technological circuits of converter steel production.

The purpose of the invention is to increase the cost-effectiveness of the converter steel production ... ....: .., ...

The drawing shows a gas outlet duct of an oxygen converter.

The path contains an oxygen converter 1, a converter gas cooler 2 (OCG) with a separator drum 3 and a steam accumulator (PVA) 4, a wet gas purifier 5, valves 6 and 7, a converter 8 and generator gas mixer 8, a compressor 9, a gate 10 of a gas tank 11 of mixed gas, a supercharger 12 for discharging a gas tank, a bypass gas pipeline (other than a gas tank) 13, a supercharger 14 for the discharge of combustion products. The bypass branch of the tract includes valves 16 and 19, a burner 17 with a furnace 18 for scrap heating (PPL), an automatic fuel-free superheater (BPP), a three-way control valve 21, a fluidized bed gas generator 22 with a blower fan 23, and an afterburner at the beginning and end of the purge.

The tract works as follows. During the purge of the oxygen converter 1, the converter gas is discharged without afterburning to the OKG 2, the main part of which enters the wet gas purifier 5 and through the open gate 6 with the closed gate 7 enters the mixer 8. Another part of the converter gas (up to 30-50%) through the open the gate 16 enters the burner 17 of the PPL 18, and for its combustion, air is supplied from the blower fan 23. The products of combustion from the PPL 18 through the open gate 19 enter the BPP 20, in which

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heating the base part of the steam outlet from the drum-separator 3 of the OKG 2, which is then sent to steam turbines, such as ПТ. Behind the BPP 20, a three-way control valve 21 is installed, which divides the flow rate of products, combustion, partially cooled in the BPP (up to 600-700 ° С) into two flows: the main part enters the gas generator 22 after preliminary mixing with steam from PVA 4 and air from the blower torus fan 23; the excess portion of the combustion products, depending on the size and operating mode of the gas generator, enters the wet gas scrubber 27 and is fed to the afterburner using the supercharger 14.

Under the action of a gasification agent obtained from a mixture of products of combustion, steam and air, in the gasifier of the fluidized bed 22 gasification of the by-product of coal refineries of the metallurgical plant (or high-ash thermal coal) is carried out. The resulting producer gas with a temperature of about 900 ° C is cooled in the heating surfaces of the gas generator to 130-140 ° C, generating superheated steam, which is sent to steam turbines of type PT. Feed water to the economizer of the gas generator comes from the DPU 24. The cooled generator gas enters the dry gas purifier 25 and through the open gate 26 -: 8 mixer 8 of the converter and generator gases

The mixed (converter-generator) gas is supplied by means of a supercharger 9 to the variable portion of the gas outlet graph through an open gate 10 to a gas holder 11, and to a constant to consumers via a bypass gas line 13. Thanks to this distribution, it is possible to reduce the size of the gas holder 11 to the minimum possible.

At the beginning and end of the purge, with the raised skirt of the radiation cooler 2, the converter gas is completely afterburned, and the tampon of the combustion products rinses the exhaust duct, removing air from it at the beginning of the purge and carbon monoxide at the end of the purge. In this case, the gate 6 is closed, and the gate 7 is open and the products of combustion from the gas purifiers 5 and 27 are discharged to the afterburner 15. Toward the end of lowering the skirt at the beginning of blowing, the gate 7 is closed and remains closed until the skirt is lifted at the end of blowing, i.e. . during the main part of the purge period. The beginning and end of the main part of the purge period is characterized by a low content of carbon monoxide in the converter gas, which in the prototype leads to its emission through the afterburner with significant environmental

damage. In the proposed path to eliminate the indicated damage, the gate 6 is opened only after ignition of the PPL burner 17 and within a few seconds before it is opened, all converter gas enters the PPL burner 17, and after opening it is divided into two streams: to the PPL and to the mixer 8. B at the end of the main period, the gate 6 closes when the gate 7 is closed, providing

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burning of all converter gas in the burner 17 PPL until the start of the skirt rise, i.e. tampon formation.

During the inter-purge period, the control valve 21 and all the valves 5 except for 7 and 26 are completely closed. The first one provides ventilation of the exhaust gas circuit: a radiation cooler 2 - wet gas cleaning 5 - gate 7 - supercharger 14 - afterburner 15. Gate 26 provides gas supply from the gas generator, Ora 22 and dry gas purification 25 to the mixer

8 and then using a supercharger 9 through a bypass gas line 13 to gas consumers {for example, heating furnaces and

5 boiler of a CHPP During this period, a mixture of steam from PVA 4 and air from a blower fan 23 is used as a gas-protecting agent in the gas generator.

The intermediate product of coal preparation plant has a high ash content (up to 50%) with a high heat of combustion (17.5-18 MJ / kg). Its burning in steam boilers of a thermal power plant in a dusty state leads to intense abrasive wear of heating surfaces and an unacceptable amount of harmful emissions into the environment. Therefore, the intermediate product of coal processing plants of metallurgical plants with a full cycle is practically not used at thermal power plants.

The technical and economic effect of the introduction of the proposed tract in comparison with the prototype is due to the full use of chemical energy

5 converter gas; full use of the physical heat of the combustion products

after the scrap furnace; with the exception of the supply of converter gas to the afterburner at the beginning and end of the purge, i.e.

0 carbon monoxide release to the environment.

An additional effect will be obtained from gasification of industrial products. Involving 5 industrial products by gasifying them in the energy balance of metallurgical plants provides significant savings in fuel costs and a significant reduction in environmental damage.

Claims (1)

The data of technical and economic calculations indicate a significant effect of. the introduction of the proposed tract despite its certain complexity in the composition of equipment and regulation. SUMMARY OF THE INVENTION Oxygen converter exhaust gas exhaust path without afterburning, comprising a radiation cooler, a wet gas scrubber, a blower, a afterburner, a bypass branch connected to the radiation cooler box, and containing a furnace for scrap scrap 0 burner, gates installed before and after the furnace, characterized in that, in order to increase the efficiency of the converter steel production, the bypass branch is additionally equipped with an autonomous fuel-free superheater, a three-way control valve, a fluidized bed gasifier for gasification of the industrial product, sequentially located behind the scrap heating furnace dry gas cleaning, a converter and generator gas mixer, and after the blower a gas holder with a bypass mixed gas pipeline is installed for.