Gasification reduction ironmaking method and gasification reduction furnace

Abstract

This invention discloses a gasification reduction ironmaking method and a gasification reduction furnace, belonging to the field of metallurgical chemical engineering. The method includes the following steps: Step 1: Carbonaceous material, oxygen, and water vapor are injected into the gasification reduction furnace from the top, and react at high temperature to generate crude syngas as the main component; Step 2: Iron-containing material is injected into the gasification reduction furnace from the bottom, and reacts with the crude syngas to generate elemental iron. This method generates crude syngas at the top of the gasification reduction furnace, while the iron-containing material reacts with it at the bottom. This avoids the overlap between the location of the reduction reaction of the iron-containing material and the location of the oxidation reaction of the carbonaceous powder, thus preventing the ash melted during crude syngas generation from encapsulating the iron-containing material and hindering the iron reduction reaction, thereby improving the efficiency of the reduction reaction of the iron-containing material.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of metallurgical chemical industry, in particular to a gasification reduction ironmaking method and a gasification reduction furnace. BACKGROUND

[0002] With the continuous emergence of CO2 emission reduction technologies, metallurgy, chemical industry and cement, as the main carbon emitters of industrial systems, are facing the remodeling of energy, structural adjustment, technology integration and resource coordination. Recycling and sustainable development are the only way out. However, these industries all discard energy and resources in the process of independent operation, resulting in waste. Steel metallurgy pursues high efficiency in the smelting process, resulting in waste heat, waste energy and other waste that cannot be fully utilized, such as blast furnace gas, converter gas, water slag sensible heat, electric furnace slag, etc. Chemical industry needs to produce synthesis gas through coal chemical industry, which also produces waste heat, steam and waste slag that cannot be fully utilized, and consumes a large amount of water resources. In the production process of cement, roasting is needed, which consumes additional energy, and silicate and aluminosilicate need to use ore resources to prepare and produce, with an industry comprehensive carbon emission proportion of about 13%, second only to the steel industry's 16%, which is a traditional energy guzzler.

[0003] In addition, China is the largest producer of alumina. In the production process of alumina, 1.0-1.8 tons of red mud (industrial solid waste discharged during the extraction of alumina in the aluminum industry, which is similar to red soil in appearance due to the large amount of iron oxide, so it is called red mud) is produced for every ton of alumina produced. From bauxite, 1 ton of aluminum metal is obtained, which produces 15-20 tons of CO2 emissions. As a major producer of alumina, China has more than 100 million tons of red mud stored every year, which is causing more and more serious pollution to the environment. It is urgent to maximize the utilization of red mud. Iron-containing red mud occupies a large amount of arable land and affects surface and groundwater quality when it is stored and buried.

[0004] In order to reduce carbon emissions, major industrial fields such as metallurgy, chemical industry, non-ferrous industry and building materials have been researching new green technology low-carbon solutions in recent years, and have made outstanding contributions. Some have already been mass-produced and applied on a large scale, but the technology of the metallurgical industry and the gasification chemical industry is still separate and not effectively coupled, resulting in waste of investment and increased comprehensive energy consumption. For example, the gas-based direct reduction shaft furnace has become the main low-carbon metallurgical technology solution in places where natural gas is abundant and cheap. It is highly dependent on high-quality ore (iron ore with TFe≥67% accounts for only 4% of iron ore) and cheap natural gas, making it difficult to be widely promoted. Some transplant the flash copper and nickel smelting technology to iron smelting, but the former is an exothermic reaction, while iron smelting is an endothermic reaction, and the two have great differences in process technology and engineering. The disposal method of red mud with multiple components has also been explored in recent years, but compared with the large stock, the effective utilization is less than 10%. Therefore, it is of great practical significance to seek a new technology coupling method that can not only meet the path of rapid and efficient metallurgy, but also provide synthetic gas for chemical industry, produce solid slag as raw material for building materials and cement, and handle a large amount of red mud or low-grade iron ore to break the dependence on high-quality iron ore.

[0005] The information disclosed in this BACKGROUND section is only for the purpose of increasing the understanding of the background of the present invention and should not be taken as an acknowledgment or any form of suggestion that this information forms prior art that is publicly known. SUMMARY

[0006] The purpose of the present application is to solve the problem that the prior art cannot couple the synthetic gas production process with the iron smelting process to reduce energy consumption, and to provide a gasification reduction iron smelting method and a gasification reduction furnace.

[0007] The present application provides a gasification reduction iron smelting method in a first aspect, which is carried out in a gasification reduction furnace comprising a reaction chamber and a quenching chamber located below the reaction chamber. The gasification reduction iron smelting method comprises the following steps:

[0008] Step 1: injecting carbon-containing substances, oxygen and steam from the upper part of the gasification reduction furnace into the gasification reduction furnace to generate crude synthetic gas through a reaction at high temperature;

[0009] Step 2: injecting iron-containing substances from the lower part of the gasification reduction furnace into the gasification reduction furnace to generate elemental iron through a reduction reaction with the crude synthetic gas;

[0010] Wherein, the carbon-containing substances are gaseous carbon-containing substances and / or solid carbon-containing substances with a particle size of less than 0.5 mm, the particle size of the iron-containing substances is less than 0.5 mm, and the mass percentage of iron oxides in the iron-containing substances is ≥35%.

[0011] The upper portion refers to the upper half of the reaction chamber; the lower portion refers to the lower half of the reaction chamber; the distance between the injection position of the carbon-containing substance, oxygen and water vapor and the injection position of the iron-containing substance is greater than or equal to 1 / 3 of the height of the reaction chamber.

[0012] In an embodiment of the present application, the distance between the injection position of the carbon-containing substance, oxygen and water vapor and the injection position of the iron-containing substance is greater than or equal to 1 / 2 of the height of the reaction chamber.

[0013] In an embodiment of the present application, the distance between the injection position of the carbon-containing substance, oxygen and water vapor and the injection position of the iron-containing substance is greater than or equal to 2 / 3 of the height of the reaction chamber.

[0014] The principle of preparing the crude synthesis gas from the reaction of the carbon-containing substance, oxygen and water vapor is the same as that of the prior art, and the reaction conditions are 1.0-8.7 MPa pressure, 1100-1600°C temperature, preferably 4.0-6.5 MPa pressure, 1200-1500°C temperature. The main components of the prepared crude synthesis gas are CO and H2.

[0015] In an embodiment of the present application, the solid carbon-containing substance is coal and / or biomass, and the gaseous carbon-containing substance is one or a combination of at least two selected from natural gas, coke oven gas, blue carbon pyrolysis tail gas and calcium carbide tail gas.

[0016] In an embodiment of the present application, the iron-containing substance is one or a combination of at least two selected from red mud, copper tailings, phosphorus slag, hematite, magnetite and vanadium-titanium magnetite.

[0017] In an embodiment of the present application, the carbon-containing substance, oxygen and water vapor are injected from the top of the reaction chamber, and / or from the sidewall of the upper half of the reaction chamber.

[0018] In an embodiment of the present application, the injection direction of the injection from the top of the reaction chamber is obliquely downward or vertically downward toward the vertical axis of the reaction chamber; and / or the injection direction of the injection from the sidewall of the upper half of the reaction chamber is horizontally toward the vertical axis of the reaction chamber.

[0019] In an embodiment of the present application, the iron-containing substance is injected from the sidewall of the lower half of the reaction chamber, and the injection direction is obliquely upward toward the vertical axis of the reaction chamber.

[0020] In an embodiment of the present application, the gas reduction iron-making method further comprises: step 3: quenching the reaction product of step 2 and the unreacted crude synthesis gas, the reaction product is solidified after quenching, and the unreacted crude synthesis gas is sent out of the gas reduction furnace for recycling after quenching.

[0021] In an embodiment of the present application, in step 3, the waste heat of the unreacted crude synthesis gas is recovered before quenching.

[0022] The second aspect of the present application provides a gas reduction furnace for the above-mentioned gas reduction iron-making method, the gas reduction furnace comprises:

[0023] The reaction chamber is the place for the gas reduction iron-making reaction;

[0024] The quenching chamber is located below the reaction chamber and is in communication with the reaction chamber through a downcomer;

[0025] The radiant waste heat recovery device is located between the reaction chamber and the quenching chamber;

[0026] The upper half of the reaction chamber is provided with an upper nozzle, and the upper nozzle is used for injecting carbon-containing substances, oxygen and water vapor;

[0027] The lower half of the reaction chamber is provided with a lower nozzle, and the lower nozzle is used for injecting iron-containing substances;

[0028] The distance between the upper nozzle and the lower nozzle is greater than or equal to 1 / 3 of the height of the reaction chamber.

[0029] In an embodiment of the present application, the distance between the upper nozzle and the lower nozzle is greater than or equal to 1 / 2 of the height of the reaction chamber.

[0030] In an embodiment of the present application, the distance between the upper nozzle and the lower nozzle is greater than or equal to 2 / 3 of the height of the reaction chamber.

[0031] In an embodiment of the present application, the gas reduction furnace further comprises a radiant waste heat recovery device, which is arranged above the quenching chamber, and the radiant waste heat recovery device is used for recovering waste heat.

[0032] In an embodiment of the present application, the radiant waste heat recovery device is a radiant screen tube.

[0033] In an embodiment of the present application, the heat transfer medium in the radiant screen tube is water.

[0034] Compared with the prior art, the present application achieves the following technical effects:

[0035] (1) Coupling the synthesis gas production process with the iron smelting process to reduce the comprehensive energy consumption. The reaction of preparing synthesis gas from carbonaceous substance, oxygen and steam is an exothermic reaction, and the reaction environment temperature can reach 1100-1600 DEG C. However, the iron smelting process needs a higher reaction temperature, and the reaction of reducing iron oxide by hydrogen is an endothermic reaction. Therefore, by coupling the synthesis gas production process with the iron smelting process, on the one hand, the synthesis gas high temperature environment can be directly used in the iron smelting process, and on the other hand, the heat released in the synthesis gas preparation process can be directly used for reducing iron oxide by hydrogen, so that the metallurgical industry technology and the gasification chemical industry technology are effectively coupled, the energy utilization rate is improved, and the comprehensive energy consumption is reduced.

[0036] (2) The synthesis gas production process and the iron oxide reduction reaction are carried out in different regions of the gasification reduction furnace, and the efficiency of the reduction reaction of the iron oxide is improved. By oxidizing the carbonaceous substance powder in the upper part of the reaction chamber of the gasification reduction furnace to generate crude synthesis gas, and spraying the iron-containing substance into the gasification reduction furnace from the lower part of the reaction chamber, the reduction reaction of the iron-containing substance and the crude synthesis gas is carried out in the lower part of the reaction chamber, so that the position of the reduction reaction of the iron-containing substance and the position of the oxidation reaction of the carbonaceous substance powder are avoided to overlap, thereby avoiding the dispersion of small droplets generated by the melting of the ash generated when the crude synthesis gas is generated to wrap the iron-containing substance, which hinders the reduction reaction of iron, or even cannot react. In addition, since the oxidation reaction mainly occurs at the top of the gasification reduction furnace, when the gas flow reaches the lower part of the gasification reduction furnace, the oxygen has been consumed, and the atmosphere is a high reduction potential atmosphere, so that the reduction reaction of the iron oxide is carried out in the excess reduction gas, which speeds up the reduction reaction of the iron oxide in the iron-containing substance and improves the efficiency of the reduction reaction of the iron-containing substance.

[0037] (3) The lower nozzle can be arranged to face upward, and the iron-containing substance is sprayed upward from the lower nozzle, so that the initial movement direction of the iron-containing substance is upward. In this way, the upward movement of the iron-containing substance and the downward movement of the synthesis gas are opposite, which further ensures the full contact of the iron-containing substance and the synthesis gas and improves the reaction speed.

[0038] (4) Compared with the high-grade oxidized pellet used in the gas-based shaft furnace, the method of the present application does not need to be made into a ball and roasted, and does not need to be coated during reduction, which reduces the dependence on natural gas, and does not need to build a heating furnace, saving a large amount of construction investment. Compared with the gas-based shaft furnace system under the same conditions, the investment is saved by 50%, the reaction efficiency and effectiveness are improved by more than 80%; compared with the powder process of the fluidized bed furnace, the method of the present application effectively avoids the problems of material adhesion and particle fusion in high temperature environment due to its rapid reaction, wide material adaptability and small material particle size. Therefore, by eliminating pelletizing, briquetting or sintering, the energy consumption of the method of the present application can be reduced by up to 30% compared with the competitive process.

[0039] (5) The method can further recover waste heat of the synthesis gas through a radiation type waste heat recovery device, thereby further saving energy consumption. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a flow chart of a gasification reduction process with iron-containing solid according to an embodiment of the present application;

[0041] Figure 2 is a structural schematic diagram of a gasification reduction furnace (with a quenching chamber) according to an embodiment of the present application;

[0042] Figure 3 is a flow chart of a gasification reduction process with iron-containing solid according to another embodiment of the present application;

[0043] Figure 4 is a structural schematic diagram of a gasification reduction furnace (with a radiation screen tube) according to another embodiment of the present application.

[0044] Explanation of Main Reference Numerals:

[0045] ① - oxygen, ② - water vapor, ③ - fuel storage bin, ④ - raw material storage bin, ⑤ - reaction chamber, ⑥ - slag lock hopper, ⑦ - venturi, ⑧ - venturi separator, ⑨ - scrubbing tower, ⑩ - crude synthesis gas, - process condensate, - black water, - black water flash evaporation and grey water recovery system, - slag removal system, - slag discharge, - cooling water, - fuel lock hopper, - raw material lock hopper, - N2 or CO2 gas, - steam drum, - boiler feed water, by-product steam;

[0046] 11 - shell, 111 - reaction chamber outer wall, 112 - quenching chamber outer wall, 12 - reaction chamber, 121 - oxidation zone, 122 - reduction zone, 13 - quenching chamber, 131 - slag removal system, 132 - synthesis gas outlet, 14 - radiation screen tube, 20 - upper nozzle, 30 - lower nozzle, 50 - downcomer. DETAILED DESCRIPTION

[0047] Unless otherwise clearly indicated, throughout the specification and claims, the term "comprise" or variations such as "comprises" or "comprising" will be understood to imply the inclusion of a stated element or group of elements but not the exclusion of any other element or group of elements.

[0048] The technical solutions of the present application are described below by specific examples. It should be understood that one or more steps mentioned in the present application do not exclude other methods and steps before and after the combination steps, or other methods and steps can be inserted between these explicitly mentioned steps. It should also be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application. Unless otherwise specified, the numbering of each method step is only for the purpose of identifying each method step, and is not intended to limit the arrangement order of each method or to limit the scope of the implementation of the present application. Changes or adjustments of the relative relationship can also be considered as the scope of the implementation of the present application without substantial technical content changes.

[0049] The raw materials and instruments used in the examples are not specifically limited in source, and can be purchased in the market or prepared according to the conventional methods well known to those skilled in the art.

[0050] The present application relates to a gasification reduction ironmaking method and a gasification reduction furnace, which are innovative in both the ironmaking method and the reaction device gasification reduction furnace. However, compared with each other, the inventor believes that the core improvement lies in the improvement of the ironmaking method, and the reaction device gasification reduction furnace can be improved according to the core improvement idea of the ironmaking method on the basis of the existing gasification furnace. Therefore, the gasification reduction ironmaking method is mainly described in detail in the specific embodiment part.

[0051] As shown in Figure 1 According to the gasification reduction ironmaking method of the preferred embodiment of the present application, the gasification reduction ironmaking method is carried out in a gasification reduction furnace, and the gasification reduction furnace includes a reaction chamber and a quenching chamber located below the reaction chamber. The gasification reduction ironmaking method includes the following steps:

[0052] Step 1: injecting carbon-containing substances, oxygen ① and steam ② from the upper part of the reaction chamber ⑤ of the gasification reduction furnace into the gasification reduction furnace to carry out a reaction at a high temperature, thereby generating a crude synthesis gas ⑩;

[0053] Step 2: injecting iron-containing substances from the lower part of the reaction chamber of the gasification reduction furnace into the gasification reduction furnace to carry out a reduction reaction with the crude synthesis gas, thereby generating elemental iron;

[0054] The carbon-containing substances are gaseous carbon-containing substances and / or solid carbon-containing substances with a particle size of less than 0.5 mm, the particle size of the iron-containing substances is less than 0.5 mm, and the mass percentage of iron oxides in the iron-containing substances is ≥ 35%;

[0055] The upper part refers to the upper half of the reaction chamber; the lower part refers to the lower half of the reaction chamber; and the distance between the injection position of the carbon-containing substances, oxygen and steam and the injection position of the iron-containing substances is greater than or equal to 1 / 3 of the height of the reaction chamber.

[0056] wherein the solid carbonaceous material is coal and / or biomass, and the gaseous carbonaceous material is one or a combination of at least two of natural gas, coke oven gas, pyrolysis tail gas of blue coal, and calcium carbide tail gas, and the coal can be all coal types. The reaction chamber of the gasification reduction furnace refers to a chamber in which the oxidation reaction and the reduction reaction are performed in the gasification reduction furnace.

[0057] In some embodiments, the carbonaceous material is fed in a dry powder state. The carbonaceous material is first dried by the gas waste heat generated by the gasification reduction furnace, and then ground to a particle size of less than 0.5 mm, preferably, a particle size of 0.05 mm with a passing rate of more than 90%. The carbonaceous material is stored in the fuel storage bin ③, and the carbonaceous material can pass through the fuel lock hopper ④ to the gasification reduction furnace. The N2 or CO2 gas The carrier gas is pressurized and dense-phase conveyed to the reaction chamber ⑤ of the gasification reduction furnace. The carbonaceous material can also be fed by other means, such as slurry feeding, liquid feeding, or gas feeding, with a solid concentration of more than 47% in the slurry feeding (no solid in the gas or liquid). The oxygen and steam are sprayed into the nozzle of the gasification reduction furnace, and the spraying nozzle can be appropriately selected according to the actual situation. For example, the oxygen and steam can be sprayed into the gasification reduction furnace through a common nozzle, or can be sprayed into the gasification reduction furnace by other means in the prior art.

[0058] In some embodiments, the oxygen and steam are sprayed into the gasification reduction furnace through a common nozzle, and the nozzle can be provided with one or more nozzles. When the nozzle is multiple, the multiple nozzles are preferably arranged on the same horizontal plane, and the multiple nozzles are uniformly distributed around the vertical axis of the gasification reduction furnace and the reaction chamber. The upper part of the reaction chamber of the gasification reduction furnace refers to the top of the reaction chamber of the gasification reduction furnace, or the area above the 1 / 2 position of the side of the reaction chamber of the gasification reduction furnace. Preferably, the upper part of the reaction chamber of the gasification reduction furnace refers to the area above the 1 / 3 position of the side of the reaction chamber of the gasification reduction furnace. More preferably, the upper part of the reaction chamber of the gasification reduction furnace refers to the area above the 1 / 4 position of the side of the reaction chamber of the gasification reduction furnace. More preferably, the upper part of the reaction chamber of the gasification reduction furnace refers to the area above the 1 / 5 position of the side of the reaction chamber of the gasification reduction furnace.

[0059] In some embodiments, the spraying direction of the oxygen and steam and the carbonaceous material is horizontal spraying, oblique downward spraying, or vertical downward spraying, in order to make the reaction position of the oxygen and steam and the carbonaceous material as much as possible in the horizontal center of the reaction chamber of the gasification reduction furnace, the spraying direction of the oxygen and steam and the carbonaceous material is towards the vertical axis of the reaction chamber of the gasification reduction furnace.

[0060] In a preferred embodiment, oxygen and steam and carbon-containing substance are injected into the gasification reduction furnace through common nozzles, the nozzles are only one, arranged in the center of the top of the reaction chamber of the gasification reduction furnace, and oxygen and steam and carbon-containing substance are injected into the gasification reduction furnace through the nozzles.

[0061] In another preferred embodiment, oxygen and steam and carbon-containing substance are injected into the gasification reduction furnace through common nozzles, the nozzles are three, arranged uniformly around the vertical axis of the gasification reduction furnace and the reaction chamber at the top of the reaction chamber of the gasification reduction furnace, the included angle formed by two adjacent nozzles in the horizontal plane is 120°, and the injection direction of oxygen and steam and carbon-containing substance is 45° downwardly inclined (the included angle between the injection direction and the horizontal plane where the nozzles are arranged) toward the vertical axis of the reaction chamber of the gasification reduction furnace.

[0062] In another preferred embodiment, oxygen and steam and carbon-containing substance are injected into the gasification reduction furnace through common nozzles, the nozzles are four, arranged uniformly around the vertical axis of the gasification reduction furnace and the reaction chamber at 1 / 4 of the height of the side wall of the reaction chamber of the gasification reduction furnace from top to bottom, the included angle formed by two adjacent nozzles in the horizontal plane is 90°, and the injection direction of oxygen and steam and carbon-containing substance is horizontal toward the vertical axis of the reaction chamber of the gasification reduction furnace. By this arrangement, oxygen and steam and carbon-containing substance injected from different nozzles meet at the horizontal center of the reaction chamber of the gasification reduction furnace, and the reaction occurs in the area close to the horizontal center, so that the concentration of the reaction raw materials is higher, the mutual contact is more sufficient, the reaction conditions such as temperature and pressure are more suitable, and the reaction speed is faster and more sufficient.

[0063] A igniter is arranged in the middle of the top of the reduction gasification furnace, and natural gas or other flammable gas is used as the initial ignition gas. During the operation, the igniter supplies the processed raw synthesis gas with a small power for a long-lasting lamp operation for recycling purposes for safety considerations. In the upper part of the reaction chamber, carbon-containing substance reacts with oxygen and steam to generate raw synthesis gas with CO and H2 as the main components under the pressure of 1.0-8.7 MPa and the temperature of 1100-1600 °C (preferably the pressure of 4.0-6.5 MPa and the temperature of 1200-1500 °C), and the specific chemical reaction formula is as follows:

[0064] C x H y O z +aO2+bH2O→cCO+dH2+eCO2+fCH4+gC(s)

[0065] Wherein, C x H y O za, b, c, d, e, f, g are the molar fractions of the components of the crude synthesis gas, a represents the carbonaceous substance, b represents the oxygen, c represents the carbon monoxide, d represents the hydrogen, e represents the carbon dioxide, f represents the methane, g represents the solid carbon, the specific composition of the crude synthesis gas depends on the raw material (carbonaceous substance) and the reaction conditions (such as temperature, gasification agent ratio), in general, the volume fraction of each component in the crude synthesis gas is as follows: carbon monoxide (CO) 10-57%, hydrogen (H2) 32-67%, carbon dioxide (CO2) 2-28%, methane (CH4) 0.1-15%, g represents the fraction of solid carbon that is not completely gasified (usually less). The molar ratio of the carbonaceous substance to oxygen and water vapor can be determined according to the reaction formula. If the carbonaceous substance is composed of multiple carbonaceous substance components, the molar ratio of the carbonaceous substance to oxygen and water vapor can be calculated according to the molecular formula of each carbonaceous substance component and its proportion. In order to ensure that the oxygen is fully reacted, so that the crude synthesis gas reaction product contains as little oxygen as possible, the actual amount of the carbonaceous substance used can be slightly higher than the calculated theoretical amount, for example, the actual amount of the carbonaceous substance used is 1.01-1.05 times the theoretical amount.

[0066] In step 2, the iron-containing substance is one or a combination of at least two of red mud, copper tailings, phosphorus slag, hematite, magnetite, and vanadium-titanium magnetite.

[0067] In some embodiments, the iron-containing substance can be sprayed into the gas reduction furnace through one or more nozzles. Preferably, the nozzles are multiple. Preferably, the multiple nozzles are arranged on the same horizontal plane, and the multiple nozzles are uniformly distributed around the vertical axis of the reaction chamber of the gas reduction furnace.

[0068] The lower part of the reaction chamber of the gas reduction furnace refers to the area from 1 / 2 of the reaction chamber of the gas reduction furnace to the bottom of the reaction chamber. Preferably, the iron-containing substance is sprayed into the gas reduction furnace from the area from 1 / 3 of the reaction chamber of the gas reduction furnace to the bottom of the reaction chamber. More preferably, the iron-containing substance is sprayed into the gas reduction furnace from the area from 1 / 4 of the reaction chamber of the gas reduction furnace to the bottom of the reaction chamber. More preferably, the iron-containing substance is sprayed into the gas reduction furnace from the area from 1 / 5 of the reaction chamber of the gas reduction furnace to the bottom of the reaction chamber.

[0069] The spraying direction of the iron-containing substance is horizontal spraying or oblique upward spraying, in order to make the reaction position of the iron-containing substance as much as possible in the horizontal center of the reaction chamber of the gas reduction furnace, the spraying direction of the iron-containing substance is towards the vertical axis of the reaction chamber of the gas reduction furnace.

[0070] In a preferred embodiment, the iron-containing material is injected into the gas reduction furnace through two nozzles, which are evenly distributed around the vertical axis of the gas reduction furnace and the reaction chamber, are arranged at the bottom of the reaction chamber of the gas reduction furnace, are on the same straight line with the center of the horizontal plane, and have the same distance from the center of the horizontal plane. The injection direction of the iron-containing material is 60° upward (the angle between the injection direction and the horizontal plane where the nozzles are located) toward the vertical axis of the reaction chamber of the gas reduction furnace.

[0071] In another preferred embodiment, the iron-containing material is injected into the gas reduction furnace through four nozzles, which are evenly distributed around the vertical axis of the gas reduction furnace and the reaction chamber, are arranged at 3 / 4 from the top to the bottom of the side wall of the reaction chamber of the gas reduction furnace, form an angle of 90° with each other on the horizontal plane, and have the injection direction of the iron-containing material being horizontal toward the vertical axis of the reaction chamber of the gas reduction furnace. By this arrangement, the iron-containing material injected from different nozzles reacts with the crude synthesis gas in the area close to the horizontal center, so that the reaction raw material concentration is higher, the mutual contact is more sufficient, the reaction conditions such as temperature and pressure are more suitable, and the reaction speed is faster and more sufficient.

[0072] Specifically, the iron-containing material is processed into fine powder with a particle size of less than 0.5 mm, dried by high-temperature flue gas, and stored in the raw material storage bin ④, and then enters the raw material lock hopper by N2 or CO2 gas The iron-containing material is pressurized and dense-phase conveyed to the lower part of the reaction chamber of the gas reduction furnace, and after being sprayed from the lower nozzle, it meets the crude synthesis gas with higher temperature. Due to the small particle size and large specific surface area of the iron-containing material, the heat transfer occurs instantaneously, and under the action of high-temperature reduction potential, the reduction reaction occurs rapidly, reducing the iron oxide to elemental iron. In actual production process, the red mud can be sprayed after the crude synthesis gas is generated for a period of time (such as a few minutes) in step 1 of oxidation reaction. In this way, on the one hand, the continuously generated crude synthesis gas forms a high-concentration high-reduction-potential synthesis gas atmosphere at the bottom of the reaction chamber of the gas reduction furnace, which can ensure that the red mud reacts in the high-reduction-potential synthesis gas atmosphere. The main reactions are as follows:

[0073] Fe x O y (s)+yH2(g)→xFe(s)+y H2O(g)

[0074] Fe x O y +yCO→xFe(s)+yCO2(g)

[0075] The reaction of H2 with iron oxides is endothermic and requires temperatures above 1000℃ for optimal results. The reaction of CO with iron oxides also requires high temperatures. The gasification temperature within the furnace is between 1100 and 1600℃, possessing high energy, which promotes rapid reaction. Iron oxides (Fe) x O y It can be Fe2O3, Fe3O4, or other iron oxides. Taking Fe2O3 as an example, the reduction sequence of iron oxide is originally Fe2O3(s) → Fe3O4 → FeO → Fe. However, due to the small particle size of the material, the heat flux is very large, and the heat required for heating is small, resulting in a very short heat transfer time. The theoretical calculation of heat transfer between the material and the high-temperature gas is only 0.003 seconds, which can be ignored. Calculations show that at 1350℃, in a reducing gas with an excess coefficient of 300% H2+CO, 50μm iron ore powder can be reduced to 99% within 0.3 seconds. At 1350℃, in a reducing gas with an excess coefficient of 200% and a H2 content of over 60%, 50μm iron ore powder can be instantly reduced to elemental iron with a 99% reduction rate in less than 0.58 seconds.

[0076] Preferably, the iron-containing material is ejected upward from the lower nozzle, allowing it to continue moving upward. This ensures that the upward-moving iron-containing material and the downward-moving crude syngas move in opposite directions, further guaranteeing sufficient contact between the iron-containing material and the crude syngas and increasing the reaction rate.

[0077] The amount of iron-containing material used can be calculated by referring to the production rate of crude syngas and the above reaction formula. First, the molar ratio of iron oxide to hydrogen and carbon monoxide during complete reaction can be calculated according to the above formula. Then, combining the ratio of hydrogen and carbon monoxide in crude syngas and the generation rate of crude syngas, the feed rate of iron oxide during complete reaction can be calculated. Next, based on the content of iron oxide in the iron-containing material, the feed rate of the iron-containing material during complete reaction can be calculated. Finally, the feed rate of the iron-containing material during complete reaction is multiplied by the feed coefficient, such as 0.01 to 0.8, preferably 0.1 to 0.5, to obtain the actual feed rate of the iron-containing material. The feed coefficient can be adjusted according to the actual reaction situation. The purpose is to ensure an absolute excess of syngas relative to the iron-containing material to guarantee a rapid and complete reaction, and to maximize the actual feed rate of the iron-containing material to avoid excessively low ironmaking efficiency.

[0078] The gasification reduction ironmaking method may further include step 3: quenching the reaction products of step 2 and the unreacted crude syngas. The reaction products are solidified after quenching, and elemental iron is further separated. The unreacted crude syngas is then sent out of the gasification reduction furnace for recycling. Specifically: the reduced elemental iron and the ash slag from the gasification of molten coal are quenched together by water spraying through a bottom ring pipe in the reaction chamber of the gasification reduction furnace, and then enter the quenching chamber along with the crude syngas (⑩). The crude syngas (⑩) and the generated carbon dioxide after passing through the quenching chamber enter the gas purification system. The slag containing elemental iron after passing through the quenching chamber enters the slag lock hopper (⑥), is crushed, and then enters the slag removal system. Slag removal system The elemental iron and the quenched glass slag are separated, and the slag is removed. The separated elemental iron is discharged and used in steel plants, while the glass slag, due to water quenching, is a high-quality silicate clinker in terms of structure and composition, serving as a cement base material and used in building materials. Simultaneously, the slag is processed from the slag removal system. Discharged cooling water Recycling and reuse.

[0079] The crude syngas⑩ produced by the gasification reduction furnace contains impurities such as fly ash and sulfides, requiring multi-stage purification. First, the crude syngas⑩ enters the quench chamber of the gasification reduction furnace for quenching, then enters the Venturi separator⑦, where fine particles are captured by high-speed water flow; subsequently, it enters the Venturi separator⑧, where larger particles are removed by centrifugal force. After solid particle separation, the crude syngas⑩ enters the scrubbing tower⑨, where soluble pollutants such as HCl, NH3, and H2S are removed by water washing, alkaline spraying, or oxidation, while process condensate is also used. The gas is further cooled. Finally, the purified crude syngas⑩ can be used for downstream applications such as chemical processing, fuel production, or power generation.

[0080] The washing wastewater produced by Venturi separator ⑧ and the black water produced by washing tower ⑨ The black water produced by the gasification reduction furnace enters the black water flash evaporation and ash water recovery system. Water resources can be recovered through preheating, vacuum evaporation, and other methods, and by-products can also be concentrated to reduce wastewater discharge.

[0081] To ensure the safe operation of the gasification reduction furnace, a layer of slag is deposited on the water-cooled wall of the upper section of the furnace after the initial start-up. During subsequent operation, the water-cooled wall is protected using the principle of "slag against slag". During normal operation, the temperature inside the furnace is 1100-1600℃. After passing through the slag layer, the temperature drops to about 500℃. Then, after passing through a 12-18mm thick screen wall and SiC filler, the temperature drops to below 300℃. The temperature of the pressurized cooling water inside the water-cooled wall is about 250℃.

[0082] Compared to high-grade oxide pellets used in gas-based vertical shaft furnaces, this method eliminates the need for pelletizing and roasting, and avoids coating treatment during reduction. It eliminates dependence on natural gas, eliminates the need for heating furnaces, and saves significant construction investment. Compared to gas-based vertical shaft furnace systems under equivalent conditions, it saves 50% on investment while increasing reaction efficiency and performance by over 80%. Compared to powder processing in fluidized bed furnaces, this process, due to its rapid reaction, wide material adaptability, and small particle size, eliminates adhesion and particle fusion at high temperatures. Therefore, by eliminating pelletizing, briquetting, or sintering, this ironmaking process can reduce energy consumption by up to 30% compared to competing processes.

[0083] Furthermore, waste heat from the crude syngas can be recovered. Specifically, before the crude syngas remaining after the reduction reaction with iron-containing substances enters the quench chamber, it is recovered using a radiant waste heat recovery device. The radiant waste heat recovery device is a radiant tube, and the heat transfer medium inside the radiant tube is water. By recovering waste heat, the heat transfer medium water is converted into water vapor. The heat of the water vapor can then be further utilized.

[0084] Furthermore, a steam drum can also be installed. Connected to a radiant waste heat recovery device (e.g.) Figure 3 (As shown). Boiler feedwater Through the air drum The downcomer is assigned to the radiant waste heat recovery unit, which recovers waste heat through the heat transfer medium water and then passes it through the steam drum. Output by-product steam

[0085] like Figure 2 As shown, a gasification reduction furnace according to a preferred embodiment of the present invention includes a reaction chamber 12, which is the site for gasification reduction ironmaking reaction; a quench chamber 13, located below the reaction chamber 12 and connected to the reaction chamber 12 via a feed pipe 50; an upper nozzle 20 is provided in the upper half of the reaction chamber 12 for injecting carbonaceous material, oxygen, and water vapor; a lower nozzle 30 is provided in the lower half of the reaction chamber 12 for injecting iron-containing material; the distance between the upper nozzle 20 and the lower nozzle 30 is greater than or equal to 1 / 3 of the height of the reaction chamber 12. The reaction chamber 12 is surrounded by an outer wall 111, and the quench chamber 13 is surrounded by an outer wall 112. The outer walls 111 and 112 constitute the shell 11 of the gasification reduction furnace. The reaction chamber 12 has two reaction zones, namely an oxidation zone 121 and a reduction zone 122. The inner side of the outer wall 111 of the reaction chamber is provided with a water-cooled wall or refractory bricks. The bottom of the quench chamber 13 is equipped with a slag discharge system 131, and the side wall of the quench chamber 13 is equipped with a synthesis gas outlet 132.

[0086] Preferably, the distance between the upper nozzle 20 and the lower nozzle 30 is greater than or equal to half the height of the reaction chamber 12. More preferably, the distance between the upper nozzle 20 and the lower nozzle 30 is greater than or equal to two-thirds the height of the reaction chamber 12.

[0087] In some specific embodiments, the upper nozzle 20 is disposed at the top of the reaction chamber 12 or at the upper 1 / 3 of the side wall of the reaction chamber.

[0088] In some specific embodiments, the upper nozzle 20 is disposed on the upper 1 / 4 portion of the side wall of the reaction chamber.

[0089] In some specific embodiments, the upper nozzle 20 is disposed on the upper 1 / 5 of the side wall of the reaction chamber.

[0090] In some specific embodiments, the upper nozzle 20 may be one or more.

[0091] In one specific embodiment, there is one upper nozzle 20, which is located at the top center of the reaction chamber 12, and the nozzle orifice of the upper nozzle 20 is vertically downward.

[0092] In some specific embodiments, there are multiple upper nozzles 20, and the multiple upper nozzles 20 are evenly arranged along the circumferential direction.

[0093] In some specific embodiments, there are multiple upper nozzles 20, and the nozzles of the multiple upper nozzles 20 are horizontal or obliquely downward.

[0094] In one specific embodiment, there are three upper nozzles 20. The three upper nozzles 20 are disposed on the top of the reaction chamber 12 and are evenly distributed around the vertical axis of the gasification reduction furnace and the reaction chamber 12. The angle formed by two adjacent upper nozzles 20 on the horizontal plane is 120°. The nozzle orifice direction of the upper nozzle 20 is towards the vertical axis of the reaction chamber 12 and the angle between the nozzle and the horizontal plane is 45°.

[0095] In one specific embodiment, there are four upper nozzles 20. The four upper nozzles 20 are arranged on the side wall of the reaction chamber 12 from the top to the bottom 1 / 4, and are evenly distributed around the vertical axis of the gasification reduction furnace and the reaction chamber 12. The included angle formed by two adjacent upper nozzles 20 on the horizontal plane is 90°, and the nozzle direction of the upper nozzle 20 is horizontal and faces the vertical axis of the reaction chamber 12.

[0096] In some specific embodiments, the lower nozzle 30 is disposed at the bottom of the reaction chamber 12 or in the lower 1 / 3 of the side wall of the reaction chamber 12.

[0097] In some specific embodiments, the lower nozzle 30 is disposed in the lower 1 / 4 portion of the side wall of the reaction chamber 12.

[0098] In some specific embodiments, the lower nozzle 30 is disposed on the lower 1 / 5 portion of the side wall of the reaction chamber 12.

[0099] In some specific embodiments, the lower nozzle 30 may be one or more.

[0100] In some specific embodiments, there are multiple lower nozzles 30, and the multiple lower nozzles 30 are evenly arranged along the circumferential direction.

[0101] In some specific embodiments, there are multiple lower nozzles 30, and the nozzles of the multiple lower nozzles 30 are horizontal or obliquely upward.

[0102] In one specific embodiment, there are two lower nozzles 30. The two lower nozzles 30 are arranged on the side wall of the reaction chamber 12 from the top 4 / 5 of the way down, and are evenly distributed around the vertical axis of the gasification reduction furnace and the reaction chamber 12. The two lower nozzles 30 are on the same straight line with the center of the horizontal plane and the distance between the two nozzles and the center of the horizontal plane is equal. The nozzle orifice direction of the lower nozzles 30 is towards the vertical axis of the reaction chamber 12 and the angle between the nozzle and the horizontal plane is 60°.

[0103] In one specific embodiment, there are four lower nozzles 30. The four lower nozzles 30 are arranged on the side wall of the reaction chamber 12 from the top three-quarters down, and are evenly distributed around the vertical axis of the gasification reduction furnace and the reaction chamber 12. The included angle formed by two adjacent lower nozzles 30 on the horizontal plane is 90°, and the nozzle direction of the lower nozzles 30 is horizontal and faces the vertical axis of the reaction chamber 12.

[0104] In some specific embodiments, the gasification reduction furnace also includes a radiant waste heat recovery device 14 (e.g., Figure 4 (As shown). The radiant waste heat recovery device 14 is located above the quench chamber 13, and the radiant waste heat recovery device 14 is used to recover waste heat.

[0105] In some specific embodiments, the radiant waste heat recovery device 14 is a radiant screen tube.

[0106] In some specific embodiments, the heat transfer medium inside the radiant tube is water.

[0107] Example 1

[0108] A gasification reduction ironmaking method is disclosed, wherein the gasification reduction ironmaking process is carried out in a gasification reduction furnace, the gasification reduction furnace comprising: a reaction chamber and a quench chamber, the quench chamber being located below the reaction chamber and connected to the reaction chamber via a feed pipe; an upper nozzle is disposed at the center of the top of the reaction chamber; three lower nozzles are disposed at 4 / 5 of the side wall of the reaction chamber, the three lower nozzles being evenly distributed along the circumference, the nozzle orifices of the three lower nozzles facing the vertical axis of the reaction chamber and forming an angle of 50° with the horizontal plane where the nozzles are located; the gasification reduction ironmaking method includes the following steps:

[0109] Step 1: 0.5mm pulverized coal, oxygen, and water vapor are injected into the gasification reduction furnace through the upper nozzle of the reaction chamber. At a pressure of 8.7MPa and a temperature of 1450℃, crude syngas is generated. The injection rates of pulverized coal, oxygen, and water vapor into the gasification reduction furnace are: pulverized coal 200kg / h; oxygen 1000kg / h; water vapor 450kg / h.

[0110] Step 2: A 0.5mm red mud powder containing 38.88% Fe2O3 by mass is injected into the gasification reduction furnace from the lower nozzle of the reaction chamber. It reacts with the crude syngas to produce elemental iron. The mass percentage of iron oxide in the red mud powder is specified. The red mud powder is injected into the gasification reduction furnace at a rate of 200 kg / h.

[0111] Example 2

[0112] A gasification reduction ironmaking method is disclosed, wherein the gasification reduction ironmaking process is carried out in a gasification reduction furnace, which includes a reaction chamber and a quench chamber. The quench chamber is located below the reaction chamber and is connected to the reaction chamber via a feed pipe. Four upper nozzles are arranged on the upper 1 / 5 of the side wall of the reaction chamber, and the four upper nozzles are evenly distributed around the vertical axis of the gasification reduction furnace and the reaction chamber. The angle formed by two adjacent upper nozzles on the horizontal plane is 90°, and the nozzle orifice direction is horizontal towards the vertical axis of the reaction chamber. Four lower nozzles are arranged on the 3 / 4 of the side wall of the reaction chamber, and the four lower nozzles are evenly distributed circumferentially. The nozzle orifice direction of the four lower nozzles is towards the vertical axis of the reaction chamber and forms an angle of 45° with the horizontal plane where the nozzles are located. The gasification reduction ironmaking method includes the following steps:

[0113] Step 1: Water-coal slurry containing 60% solids and oxygen are injected into the gasification reduction furnace through the upper nozzle of the reaction chamber. Crude syngas is generated at a pressure of 6.5 MPa and a temperature of 1200℃. The injection rates of coal slurry and oxygen into the gasification reduction furnace are 1500 kg / h for coal slurry and 1800 kg / h for oxygen.

[0114] Step 2: 0.05 mm hematite containing 55% Fe2O3 by mass is injected into the gasification reduction furnace from the lower nozzle of the reaction chamber to react with crude syngas and generate elemental iron; the rate at which the hematite powder is injected into the gasification reduction furnace is 800 kg / h.

[0115] Step 3: The reaction products from Step 2 and the crude syngas that did not participate in the reaction are quenched. The reaction products are solidified after quenching and further separated into elemental iron. The crude syngas that did not participate in the reaction is sent out of the gasification reduction furnace for recycling after quenching.

[0116] Example 3

[0117] A gasification reduction ironmaking method is disclosed, wherein the gasification reduction ironmaking process is carried out in a gasification reduction furnace, which includes a reaction chamber and a quench chamber. The quench chamber is located below the reaction chamber and is connected to the reaction chamber via a feed pipe. Three upper nozzles are arranged on the upper 1 / 3 of the side wall of the reaction chamber. The three upper nozzles are evenly distributed around the vertical axis of the gasification reduction furnace and the reaction chamber. The angle formed by three adjacent upper nozzles on the horizontal plane is 120°, and the nozzle orifice direction faces the vertical axis of the reaction chamber and forms an angle of 30° with the horizontal plane where the nozzle is located. Five lower nozzles are arranged at 5 / 6 of the side wall of the reaction chamber. The five lower nozzles are evenly distributed along the circumference, and the nozzle orifice direction faces horizontally towards the vertical axis of the reaction chamber. The gasification reduction ironmaking method includes the following steps:

[0118] Step 1: Natural gas, oxygen, and water vapor are injected into the gasification reduction furnace from one-third of the side wall of the reaction chamber. Crude syngas is generated at a pressure of 3.5 MPa and a temperature of 1300℃. The injection rates of natural gas, oxygen, and water vapor into the gasification reduction furnace are as follows: natural gas 800 kg / h; oxygen 1250 kg / h; water vapor 900 kg / h.

[0119] Step 2: 0.15mm magnetite containing 45% Fe3O4 by mass is injected into the gasification reduction furnace from 5 / 6 of the side wall of the reaction chamber to react with crude syngas and generate elemental iron; the magnetite powder is injected into the gasification reduction furnace at a rate of 500kg / h.

[0120] Step 3: The reaction products from Step 2 and the crude syngas that did not participate in the reaction are quenched. The reaction products are solidified after quenching and further separated into elemental iron. The crude syngas that did not participate in the reaction is sent out of the gasification reduction furnace for recycling after quenching.

[0121] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A gasification reduction ironmaking method using an iron-containing material as a raw material, characterized by, The gasification reduction iron-making method is performed in a gasification reduction furnace, which comprises a reaction chamber and a quenching chamber below the reaction chamber, and comprises the following steps: Step 1: injecting carbon-containing substances, oxygen and steam into the gasification reduction furnace from the upper part of the reaction chamber of the gasification reduction furnace, and reacting at high temperature to generate crude synthesis gas; Step 2: injecting iron-containing substances into the gasification reduction furnace from the lower part of the reaction chamber of the gasification reduction furnace, and reacting with the crude synthesis gas to generate elemental iron; Wherein, the carbon-containing substances are gaseous carbon-containing substances and / or solid carbon-containing substances with a particle size of less than 0.5 mm, the particle size of the iron-containing substances is less than 0.5 mm, and the mass percentage of iron oxides in the iron-containing substances is ≥ 35%; The upper part refers to the upper half of the reaction chamber; the lower part refers to the lower half of the reaction chamber; the distance between the injection position of the carbon-containing substances, oxygen and steam and the injection position of the iron-containing substances is greater than or equal to 1 / 2 of the height of the reaction chamber; The iron-containing substances are injected from the side wall of the lower half of the reaction chamber, and the injection direction is obliquely upward toward the vertical axis of the reaction chamber.

2. The method of claim 1, wherein the ironmaking process is a gas-based reduction process. The solid carbon-containing substances are coal and / or biomass, and the gaseous carbon-containing substances are selected from one or a combination of at least two of natural gas, coke oven gas, blue carbon pyrolysis tail gas and calcium carbide tail gas.

3. The method of claim 1, wherein the ironmaking process is a gas-based reduction process. The iron-containing substances are selected from one or a combination of at least two of red mud, copper tailings, phosphorus slag, hematite, magnetite and vanadium-titanium magnetite.

4. The method of claim 1, wherein the ironmaking process is a gas-based reduction process. The carbon-containing substances, oxygen and steam are injected from the top of the reaction chamber, and / or from the side wall of the upper half of the reaction chamber.

5. The method of claim 4, wherein the ironmaking process is a gas-based reduction process. The injection direction from the top of the reaction chamber is obliquely downward or vertically downward toward the vertical axis of the reaction chamber; and / or the injection direction from the side wall of the upper half of the reaction chamber is horizontally toward the vertical axis of the reaction chamber.

6. The method of claim 1, wherein the ironmaking process is a gas-based reduction process. The gasification reduction iron-making method further comprises: Step 3: quenching the reaction products of step 2 and the crude synthesis gas that does not participate in the reaction, solidifying the reaction products after quenching, and further separating elemental iron, and sending the crude synthesis gas that does not participate in the reaction out of the gasification reduction furnace after quenching for recycling.

7. The method of gas reduction iron smelting according to claim 6, characterized in that, In step 3, the waste heat of the crude synthesis gas that does not participate in the reaction is recovered before quenching.

8. A gas reduction furnace for use in the iron-smelting method according to any one of claims 1 to 7, characterized by, The gasification reduction furnace comprises: The reaction chamber is the place where the gasification reduction iron-making reaction is performed; The quenching chamber is located below the reaction chamber and is in communication with the reaction chamber through a discharge pipe; The upper half of the reaction chamber is provided with an upper nozzle for injecting carbon-containing substances, oxygen and steam; The lower half of the reaction chamber is provided with a lower nozzle for injecting iron-containing substances; the lower nozzle is arranged on the side wall of the reaction chamber, and the injection direction of the lower nozzle is obliquely upward toward the vertical axis of the reaction chamber; The distance between the upper nozzle and the lower nozzle is greater than or equal to 1 / 2 of the height of the reaction chamber.

9. The gas reduction furnace according to claim 8, characterized in that, The distance between the upper nozzle and the lower nozzle is greater than or equal to 2 / 3 of the height of the reaction chamber.

10. The gas reduction furnace according to claim 8, characterized by The upper nozzle is arranged at the top center of the reaction chamber, and the jet direction of the upper nozzle is vertically downward; and / or the upper nozzle is arranged at a non-central position of the top of the reaction chamber, and the jet direction of the upper nozzle is obliquely downward toward the vertical axis of the reaction chamber. And / or the upper nozzle is arranged on the side wall of the reaction chamber, and the jet direction of the upper nozzle is horizontally toward the vertical axis of the reaction chamber.

11. The gas reduction furnace of claim 8, wherein, The gasification reduction furnace further comprises a radiation waste heat recovery device arranged above the quenching chamber, and the radiation waste heat recovery device is used for recovering waste heat.

12. The gas reduction furnace of claim 11, wherein, The radiation waste heat recovery device is a radiation screen tube.

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