RU139174U1 - DEVICE FOR PREPARATION AND DELIVERY OF THE HEAT CARRIER IN THE METALIZATION FURNACE - Google Patents

Abstract

1. The device for the preparation and supply of coolant to a metallization furnace containing at least two coal gasifiers, each of which is connected via a gaseous fuel supply line to the nozzles of a metallization furnace, characterized in that the coal gasifiers are configured to simultaneously produce hot gas below and in the cold - at the top, while the device is equipped with equipment installed in the gaseous fuel supply line from the gasifier to the nozzles of the metallization furnace cleaning the product gas from the gasifier each comprising a cyclone cleaning of hot gas from the gasifier and cleaning precipitator of cold gas from the gasifier, the hot and cold collector gas low pressure apparatus and increase the gas pressure gas line davleniya.2 increased. The device according to claim 1, characterized in that the gas pressure increasing device is provided with at least one fan. The device according to claim 1, characterized in that the gaseous fuel supply line from the gasifier to the nozzles of the metallization furnace further comprises an air cooler installed after the cyclone for cleaning hot gas from the gasifier. A device according to one of claims 1 or 3, characterized in that it is equipped with a cold gas scrubber mixer from the electrostatic precipitator with hot gas from the air cooler installed in the gaseous fuel supply line from the gasifier to the nozzles of the metallization furnace. 5. A device according to one of claims 1, 3 or 4, characterized in that it is equipped with an electrostatic precipitator installed after the cold gas scrubber mixer from the electrostatic precipitator from th

Description

The proposed solution relates to the technology of metal reduction by heating a layer of a material containing metal oxide and a carbon reducing agent and can be used in the manufacture of a metallized product, such as iron, in a moving hearth furnace.

In the technology of direct reduction of metal from an iron-carbon-containing material containing metal oxide and a reducing agent, the choice of a carbon reducing agent and a type of fuel for heating the processed iron-carbon-containing material is important. The reducing agent must ensure effective interaction with the metal oxide during the entire processing time and throughout the volume of the material loaded onto the under furnace. At the same time, carbon material should be scarce and inexpensive. The fuel reagent supplied through the nozzles to the furnace must ensure effective interaction of the reaction components and the necessary conditions for obtaining a high-quality product.

The use of less expensive types of raw materials and energy carriers, the use of technologies for preparing raw materials for use in the process that do not require significant energy costs and special expensive equipment, and the most efficient use of the energy component of the process are preferable.

The known "Method for producing molten iron" (RF patent 2293121, C21B 13/14, 2007, [1])), the first stage of which implements the direct metal reduction technology by heating a layer of a material containing metal oxide and a carbon reducing agent in a furnace with moving hearth. The method in the first stage involves introducing a mixture of starting materials containing iron oxide-based material and a carbon-containing reducing agent into a heating reduction furnace in order to reduce iron oxide in the starting material mixture using a carbon-containing reducing agent to solid reduced iron.

The process is carried out on the production line described in the description, including the preparation of iron-containing material, equipped with a dryer, mill and material transportation lines, the preparation of carbon-containing material, equipped with a crusher and material transportation lines, the preparation of iron-carbon agglomerates, equipped with a mixer of raw iron-carbon components , binder and auxiliary materials, sinter plant, drying plant and t lines ansportirovki linking it with portions of preparation of raw materials and with a rotary hearth furnace provided with a loading and unloading devices, nozzles for supplying fuel, the fuel supply line is connected with the portion preparing and feeding the coolant through the device and for discharging exhaust gas from the gas purification installation. A boiler for extracting heat from the exhaust gases and a heat recuperator in the form of an air heat exchanger connected by a hot air supply line to the drying unit are installed in the furnace exhaust gas exhaust line in front of the gas treatment plant.

To carry out the process, dust-free exhaust hot gas from a smelting furnace is fed into the rotary kiln from the second stage of this technology — production of molten iron and fuel in the form of natural gas or powdered coal.

The main disadvantages of the known solutions are as follows.

The supply of exhaust hot gas from the melting furnace to the rotary kiln from the second stage of the process requires additional costs for dedusting the gas, and given that the gas to be purified has a high temperature, such purification is very costly and ineffective, both technologically and in terms of the service life of the treatment equipment. If the degree of dust removal is not high enough, it can accumulate in a rotary kiln, which will lead to violations of the stable continuous operation of the equipment.

The supply of fuel in the form of natural gas or powdered coal to a rotary kiln increases the cost of implementing the technology, both in terms of the cost of reagents and equipment.

A known production line for the production of a metallized product, including a section for crushing coal, a section for preparing iron-carbon-containing agglomerates, equipped with a mixer of raw iron-carbon-containing components, an agglomeration unit, a drying unit, a section for preparing and supplying a coolant, a metallization furnace with a rotating hearth, equipped with loading devices and unloading, nozzles for supplying fuel, connected by transportation lines to the site for the preparation of iron-carbon-containing ag omerates, in the preparation and supply of the coolant and through the exhaust gas removal device with a gas treatment unit, moreover, a heat recuperator in the form of an air heat exchanger connected to the hot air supply line with a drying unit in which the preparation and supply section is installed in the exhaust gas exhaust line before the gas treatment installation the fuel is equipped with at least two coal gasifiers, each of which is connected by transportation lines to the coal crushing section and the gaseous supply line fuel with nozzles of a metallization furnace, to which a heat recuperator is also connected by a hot air supply line. At the same time, the coal crushing section is equipped with at least two crushers (RF patent for ПМ No. 87166, C21B 13/14, C21B 13/08, 2009, [2]).

By appointment, by technical nature, by the presence of similar features, this solution was chosen as the closest analogue.

The main disadvantage of the known solution is the gas supply directly from coal gasifiers through nozzles into the working space of the furnace. Such a scheme cannot ensure the stable operation of nozzles and the recovery process, since gasifiers operate at low pressure (100-200 mm water column), and the incoming gaseous fuel has an unstable composition. In addition, resinous compounds, dusty particles contained in a gaseous product exiting the coal gasifier, are deposited on the walls of gas-fuel lines and on nozzle nozzles, thereby violating the stable supply of gaseous fuel to the furnace, and the service life of gas-supplying equipment is reduced.

The objective of the proposed solution is safe long-term and stable operation of the gas heating system of the metallization furnace, increasing the efficiency of the gasification section and the furnace.

Technical results are: a stable process for producing a metallized product by reduction with low-calorie gas obtained by gasification of coal with a high coefficient of efficiency of the gasification section and metallization furnace.

Technical results are achieved by the fact that in the device for preparing and supplying coolant to a metallization furnace containing at least two coal gasifiers, each of which is connected via a gaseous fuel supply line to nozzles of a metallization furnace, coal gasifiers are configured to simultaneously produce hot gas below and in the cold - at the top, while the device is equipped with metal gasses installed in the gaseous fuel supply line from the gasifier to the nozzles of the furnace ization equipment cleaning products from each gasifier comprising a cyclone cleaning of hot gas from the gasifier and cleaning precipitator of cold gas from the gasifier, the hot and cold collector of the low-pressure gas, increasing the gas pressure device and the pressure-gas line.

In this case, the device for increasing gas pressure can be equipped with at least one fan, the line for supplying gaseous fuel from the gasifier to the nozzles of the metallization furnace may additionally contain an air cooler installed after the cyclone for cleaning hot gas from the gasifier, the device can be equipped with a cold gas scrubber-mixer from electrostatic precipitator with hot gas from the air cooler installed in the gaseous fuel supply line from the gasifier to the nozzles of the metallization furnace, device m Jet be provided with electrostatic established after cold-gas scrubber from the electrostatic mixer with hot gas from the air cooler, installed in the line supplying the fuel gas from the gasifier to the nozzles metallization furnace.

A comparative analysis of the proposed technical solution with the solution selected as the closest analogue shows the following.

The proposed solution and the solution for the closest analogue are characterized by similar features:

- a device for preparing and supplying coolant to a metallization furnace, comprising:

- - at least two coal gasifiers;

- - - each gasifier is connected by a gaseous fuel supply line to nozzles of a metallization furnace.

The proposed solution differs from the closest analogue in the following features:

- coal gasifiers are made possible to simultaneously obtain gaseous fuel in hot form below and in cold form above;

- the device is equipped with equipment for cleaning products from each gasifier installed in the gaseous fuel supply line from the gasifier to the nozzles of the metallization furnace, containing:

- - a cyclone for cleaning hot gas from a gasifier;

- - electrostatic precipitator for cleaning cold gas from a gasifier;

- the device is also equipped with:

- - a collector of hot and cold gases of low pressure;

- - a device for increasing gas pressure;

- - high pressure gas line.

In this case, the device for increasing gas pressure can be equipped with at least one fan, the line for supplying gaseous fuel from the gasifier to the nozzles of the metallization furnace may additionally contain an air cooler installed after the cyclone for cleaning hot gas from the gasifier, the device can be equipped with a cold gas scrubber-mixer from electrostatic precipitator with hot gas from the air cooler installed in the gaseous fuel supply line from the gasifier to the nozzles of the metallization furnace, device m Jet be provided with electrostatic established after cold-gas scrubber from the electrostatic mixer with hot gas from the air cooler, installed in the line supplying the fuel gas from the gasifier to the nozzles metallization furnace.

The presence in the proposed solution of signs that are different from the signs characterizing the technical solution for the closest analogue allows us to conclude that the proposed solution meets the condition of patentability of the utility model of "novelty."

The technical essence of the proposed technical solution is as follows.

The process of reducing metal from oxide in a rotary hearth furnace using iron-carbon briquettes arranged in the form of a briquette is dynamic and is characterized by the need to maintain certain ratios of metal oxide - reducing agent and temperatures in the working zones of the furnace in fairly narrow intervals. Providing optimal conditions for such a process is a rather difficult task and in the proposed solution is achieved, firstly, by using gasifiers, the design of which allows to obtain two gases, a cold top and a hot bottom, and secondly, by preparing gaseous fuel supplied to the nozzles of the furnace. Separate gas production allows gasification of coal to the fullest extent possible, obtaining high-quality gas of a given composition and more efficiently organizing gas purification.

The preparation of gaseous fuel consists in the fact that the gas obtained in gasifiers is cleaned: in a cyclone, hot gas is cleaned of dust and partially cooled, and in the cold top gas purification electrostatic precipitator it is cleaned of tar and dust. Each unit installed in addition to the main purification scheme independently increases the degree of gas purification: in the air cooler, the gas is cooled and additionally cleaned of dust and tar, the gas is cooled by the scrubber-mixer and the phenols are cleaned by dust, after the gas scrubber-mixer in the electrostatic precipitator the gas is cleaned of light oils and dust. Additionally installed equipment for gas purification and conditioning improves its consumer properties. In the low pressure gas manifold, gasification of gasifier gases is mixed and averaged, which increases the stability of the composition.

The proposed device for the preparation and supply of coolant to a metallization furnace, as part of a technological line for the production of a metallized product, (Figure 1), including a material preparation section 1 (coal, iron-carbon briquettes), connected by a transportation line of 2 prepared iron-carbon briquettes to the furnace metallization 3 with a rotating hearth, equipped with nozzles 4 for supplying gaseous fuel, contains a line for transporting 5 prepared coal to coal gasifiers 6, each of which provides simultaneous production of gaseous fuel in the hot form below and in the cold form above. Each coal gasifier 6 is connected by a gas duct 7 to a cyclone 8 for cleaning hot gas. Each coal gasifier 6 is connected by a gas duct 9 with an electrostatic precipitator 10 for purifying cold gas. The electrostatic precipitators 10 are connected by gas ducts 11 to a low-pressure gas collector 12. Cyclones 8 are connected by gas ducts 13 to a low-pressure gas collector 12. The low-pressure gas collector 12 is connected by low-pressure gas manifold gas ducts 14 to gas pressure increasing fans 15. Gas pressure increasing fans 15 are connected by gas ducts 16 with a line of high-pressure gas 17. The line of high-pressure gas 17 passes through a heat recuperator 18, through which a stream of exhaust gas flows through line 19 from a metal furnace lysis 3 and which is connected to the chimney 20. The high pressure gas, heating in the heat recuperator 18, through the duct 21 enters the nozzles 4 of the metallization furnace 3.

The proposed device for the preparation and supply of coolant to a metallization furnace, as part of a technological line for the production of a metallized product, operates as follows.

From the material preparation section 1, pre-prepared iron-carbon-containing briquettes are delivered to the metallization furnace 3 with a rotating hearth from the material preparation section 1 (briquettes are pretreated with hot air coming from heat recuperator 18 made in the form of an air heat exchanger before loading), and via transport line 5 prepared coal for coal gasifiers 6, each of which ensures the simultaneous production of gaseous fuels in the hot form below and in the cold form above. The hot gas obtained in each gasifier 6 is fed through a gas duct 7 to a cyclone 8 for purification, where it is cleaned of dust, partially cooled and fed through a gas duct 13 to a low pressure gas collector 12. The cold gas obtained in each gasifier 6 is fed through an gas duct 9 to an electrostatic precipitator 10 where it is cleaned of tar, dust and purified gas from the electrostatic precipitator 10 through a gas duct 11 enters the low-pressure gas manifold 12. In the manifold 12, cold and hot gases are mixed and averaged, and then the mixed gas flows into the fan 15. The fan 15 increases the gas pressure and through the high pressure gas duct 16 delivers it to the high pressure gas line 17. Through the high pressure line 17, the gas enters the heat recuperator 18, where it is heated to a predetermined temperature and fed through the gas duct 21 to the nozzles 4 ring furnace metallization 3. In the heat recuperator 18, the air is heated and through the air duct 22 enters the nozzles 4 of the ring furnace metallization 3. When the briquettes are heated in the metallization furnace 3 from the combustion of gas, iron is reduced. Then the metallized product is discharged from the hearth of the furnace 3 using a discharge device. Hot exhaust gas from the furnace 3 through the exhaust device through the exhaust gas line 19 enters the heat recuperator 18, where it cools, heats the gas and air for nozzles 4 and air for drying the briquette. After the heat recuperator 18, the spent and cooled gas of the furnace enters the chimney 20.

The proposed device for the preparation and supply of coolant to the metallization furnace (Figure 2), if necessary, may further comprise an air gas cooler 23, which cools and further purifies the hot gas from dust and resinous substances. An air gas cooler 23 is installed after the cyclone 8 for cleaning the hot gas from the gasifier and connected to it by a duct 26.

The device may also further comprise a cold gas scrubber mixer 24 from an electrostatic precipitator with hot gas from an air cooler that mixes, cools and further purifies the gas from dust and phenolic substances. The scrubber mixer 24 is connected to an air gas cooler 23 and to an electrostatic precipitator 10.

The device may also further comprise an electrostatic precipitator 25 installed after the cold gas scrubber-mixer 24 from the electrostatic precipitator 10 with hot gas from the air cooler 23.

After passing through additional devices and additional processing, the gas stream through the gas duct 13a enters the low-pressure gas manifold 12, and then through the low-pressure manifold gas duct 14, the mixed gas enters the fan 15. The fan 15 increases the gas pressure and supplies it to the line through the high-pressure gas duct 16 high pressure gas 17. On line 17, the gas enters the heat recuperator 18, where it is heated to a predetermined temperature and through the duct 21 enters the nozzles 4 of the annular metallization furnace 3. In the heat recuperator 18 also the air is heated and through the air duct 22 enters the nozzles 4 of the annular metallization furnace 3.

Using the proposed device for the preparation and supply of coolant to a metallization furnace, in which the line for supplying gaseous fuel from coal gasifiers to nozzles of a rotary hearth furnace is additionally equipped with equipment for cleaning gaseous products from each gasifier, it allows to stabilize the process of direct reduction of metal from oxide and increase the yield of a commercial product and its quality.

INFORMATION

1. RF patent 2293121, C21B 13/14, 2007

2. RF patent for PM No. 87166, C21B 13/14, C21B 13/08, 2009

Claims (5)

1. The device for the preparation and supply of coolant to a metallization furnace containing at least two coal gasifiers, each of which is connected via a gaseous fuel supply line to the nozzles of a metallization furnace, characterized in that the coal gasifiers are configured to simultaneously produce hot gas below and in the cold - at the top, while the device is equipped with equipment installed in the gaseous fuel supply line from the gasifier to the nozzles of the metallization furnace cleaning the product gas from the gasifier each comprising a cyclone cleaning of hot gas from the gasifier and cleaning precipitator of cold gas from the gasifier, the hot and cold collector of the low-pressure gas, increasing the gas pressure device and the pressure-gas line. 2. The device according to claim 1, characterized in that the device for increasing gas pressure is equipped with at least one fan. 3. The device according to claim 1, characterized in that the gaseous fuel supply line from the gasifier to the nozzles of the metallization furnace further comprises an air cooler installed after the cyclone for cleaning hot gas from the gasifier. 4. The device according to one of claims 1 or 3, characterized in that it is equipped with a cold gas scrubber mixer from the electrostatic precipitator with hot gas from the air cooler installed in the gaseous fuel supply line from the gasifier to the nozzles of the metallization furnace. 5. The device according to one of claims 1, 3 or 4, characterized in that it is equipped with an electrostatic precipitator installed after the cold gas scrubber mixer from the electrostatic precipitator with hot gas from the air cooler installed in the gaseous fuel supply line from the gasifier to the nozzles of the metallization furnace .

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