WO2019201183A1

WO2019201183A1 - Cokeless cupola furnace and method of melting iron using same

Info

Publication number: WO2019201183A1
Application number: PCT/CN2019/082504
Authority: WO
Inventors: 王宇新; 赵占良; 赵保平
Original assignee: 广东北晟益通实业有限公司
Priority date: 2018-04-17
Filing date: 2019-04-12
Publication date: 2019-10-24
Also published as: CN108413767A

Abstract

A cokeless cupola furnace comprises a furnace body (1) and a heating source (2). The furnace body (1) has an internal integrated vertical through-channel structure. A material feed opening (6) and at least one molten iron outlet (7) are arranged at the furnace body (1). The material feed opening (6) and the molten iron outlet (7) communicate with each other by means of the through-channel structure. A hearth region and a melting zone of the through-channel structure are configured to be a filled section (11) accommodating high-carbon balls (5) that support a furnace charge (8). The heating source (2) is a natural gas burner. A nozzle (21) of the natural gas burner is arranged at the furnace body (1) and positioned at the high-carbon ball (5)-filled section (11). In the cupola furnace, high-carbon balls (5) function as a material-supporting column in place of a water-cooled grating and a bed of refractory balls, thereby preventing potential safety risks caused to equipment by a water cooled grating, and preventing loss of heat to cooling water in a steel pipe of the water cooled grating.

Description

[Name of invention made by ISA according to Rule 37.2] Non-focus cupola and method of using the device to melt iron

Technical field

The present invention relates to the field of smelting equipment for cast iron, and more particularly to a novel coke-free cupola and a method of using the device to melt iron.

Background technique

Since the 1980s, the United Kingdom and Germany have invented a non-focal cupola furnace that uses a natural gas-oxygen burner as a heat source for supply, and replaces coke with a rich amount of clean energy, natural gas, to achieve good energy-saving and emission reduction effects. Compared with the traditional coke cupola, the same amount of cast iron is melted, and the natural gas non-coke cupola can reduce CO ₂ emissions by more than 70% and reduce SO ₂ emissions by more than 90%. At the same time, the structure of the non-focusing cupola equipment, especially the supporting environmental protection equipment is relatively simple, the investment is small, and it can be modified on the basis of the original cupola equipment, without having to build a new furnace, so it is easy to be in the majority of foundry enterprises, especially the annual output. It is promoted in small and medium-sized foundries below 1-10 million tons.

However, the currently used coke-free cupola still has the following problems:

1 Since coke is not supported as a column support in the furnace, a water-cooled grate is added above the natural gas burner to carry the charge column. The water-cooled grate is a row of water-cooled forced-cooled steel pipes installed above the high-temperature flame. The working conditions of the steel pipes in these high-temperature zones are worse than that of the water-cooled furnace wall and the water-cooled tuyere, which not only increases the safety risk of the equipment but also increases the safety risk of the equipment. The temperature loss of the molten iron droplets passing through the water-cooled grate also increases the heat loss carried by the cooling water in the water-cooled grate steel pipe. Moreover, since it is necessary to rely on the water-cooled grate as the column support, the volume of this type of cupola is limited, making it impossible to prepare a large-scale coke-free cupola of 30 t/h or more.

2 cupola in the process of normal melting of cast iron, the water-cooled grate needs to lay a layer of ceramic balls, the thickness of the ceramic ball layer is generally required to be 400-700mm (ceramic ball diameter of about 180-200mm), as the iron liquid overheated " "The hearth", because the ceramic ball is continuously lost during the melting process of the cupola, it is necessary to refill the ceramic ball without breaking the furnace during the whole process (in the case of the German 15t/h non-coke cupola, for example, it needs to be supplemented with each batch of charge). Water-cooled furnace grid porcelain ball). Since the ceramic ball only plays the role of supporting and raising the hearth in the furnace, and has no beneficial effect, it can only consume energy, and eventually it becomes slag; in addition, the price of the ceramic ball is several times of the coke price, so The ceramic balls consumed every day also increase the cost of opening the furnace.

3 Due to the above reasons, the tapping temperature of the non-coke cupola is relatively low (generally only about 1400 °C), so it is necessary to configure a high-powered core-frequency induction electric furnace as the front furnace to provide additional heating and heat preservation functions. In order to melt the high temperature qualified iron liquid of 1500 °C.

4 When adding a large amount of scrap material to the coke-free cupola furnace, it is necessary to add a recarburizing agent to the molten iron in the forehearth furnace to carry out the iron-carbon carbonization operation.

At present, the restrictions on coke cupola in the foundry industry are increasingly strict. In order to adapt to China's increasing energy conservation and emission reduction, as well as the current increasing number of natural gas extraction, the price is increasingly stable and falling, the domestic foundry industry promotes non-focal The cupola has been put on the agenda. The development of a non-focus cupola that can overcome the above defects has become an urgent problem to be solved in the industry. Therefore, it is necessary to develop a new type of coke-free cupola which can retain the advantages of the above-mentioned coke-free cupola and avoid the disadvantages listed above, so as to adapt to the development of the green casting industry.

Summary of the invention

According to an aspect of the invention, a novel coke-free cupola is provided to solve at least one of the above technical problems.

The invention firstly provides a novel coke-free cupola furnace, comprising a furnace body and a heating source, wherein the whole body of the furnace body is a hollow structure which is vertically penetrated, and the furnace body is provided with a feeding port and at least one tapping port, a feeding port and a discharging port. The iron mouth is connected through the cavity structure, wherein

The furnace zone and the melting zone of the cavity structure are both arranged to receive a filling section of the high carbon ball supporting the charge.

The heating source is a natural gas burner, and the burner of the natural gas burner is disposed on the furnace body and is located in a filling section of the high carbon sphere.

Therefore, the inside of the furnace body provided by the invention is a cavity structure, and the upper and lower sides are penetrated, and the furnace zone and the melting zone of the cavity structure are all provided with filling sections of high carbon balls, which breaks through the prior art without coke Furnace cylinders are usually provided with hollow structures to improve technical barriers and cognitive barriers to combustion efficiency;

Secondly, filling the high-carbon ball instead of the water-cooled grate as the support of the charge not only superheats the molten iron, but also omits the water-cooled grate (the water-cooled grate is a row of water-cooled steel pipes installed in a high temperature environment) Therefore, the safety risk caused by the abnormal working condition of the steel pipe is avoided, the safety hazard existing in the production operation of the existing device is eliminated, and the limitation on the volume of the non-focus cupola is also eliminated, so that different melting rates can be prepared according to requirements. The non-focus cupola furnace, in particular, makes it possible to prepare a large-scale coke-free cupola of 30t/h and above;

Furthermore, the use of a natural gas burner as a heating source not only provides a high temperature and is more energy efficient, but also provides a high temperature gas of water vapor and carbon dioxide to the burner of the natural gas burner, thereby avoiding high oxygen content in the high temperature gas. The carbon ball is oxidized to reduce the loss of high carbon balls; in addition, since the natural gas-oxygen high temperature burner directly supplies the heat required for cupola melting, in addition to high carbon balls such as carbon balls, waste graphite electrode dicing does not exist in coke Such pores, low reactivity, slow consumption, and high stability of the support column are not easy to fluctuate, so there is no need to worry about the "wind balance" problem, and there will be no more "bottom focus height reduction", "falling", "Black slag, slag", iron oxide oxidation and other common accidents of the cupola, so the furnace condition is more stable, ensuring normal production order and casting quality; because the molten iron is neither oxidized nor sulfurized in the cupola Less, so the purity of the molten iron is relatively high, suitable for the production of high quality spheroidal graphite cast iron.

In some embodiments, the filled high carbon spheres are carbon ball and/or graphite electrode dicing. Therefore, when the high carbon ball is a carbon ball, since the carbon ball is dense and non-porous and the surface is covered with molten iron, the reactivity with the high temperature gas in the furnace is low, and the carbon ball burning rate and the amount of waste residue can be greatly reduced. It also has a carbon-increasing effect, making process optimization and operation easier. Since the height from the top surface of the high carbon ball to the burner affects the temperature and melting rate of the molten iron, in a specific practice, it is preferred to set the distance between the top surface of the high carbon ball and the burner to be 400-700 mm, high carbon ball. The higher the height from the top surface to the burner, the higher the temperature of the molten iron, but the melting rate will decrease. Conversely, the lower the height, the higher the melting rate, but the lower the temperature of the molten iron; Within, combined with a large number of practices and summaries, the best balance between melting rate and molten iron temperature is guaranteed.

In some embodiments, the diameter of the filled high carbon ball needs to be set according to the requirements of the furnace body, and the size is applicable, and generally can be set to 150-300 mm. Thereby, the high carbon ball size can be ensured to be uniform, and when it is large, good gas permeability and thermal efficiency are ensured; however, it is too large, burns, and has low thermal efficiency, so after extensive practice and summary, the embodiment of the present invention Preferably, the high carbon ball has a diameter of 150-300 mm to achieve good gas permeability and high thermal efficiency in the hearth.

In some embodiments, the charge is placed directly on a high carbon ball, and the charge is a metal charge, including pig iron, recycled charge, and scrap. Thus, when the charge is melted into molten iron, the high-carbon ball also acts as a superheat during the dropping of the iron droplets along the high-carbon ball, which greatly increases the temperature of the molten iron, making the device more energy-efficient and material-saving.

In some embodiments, the natural gas burner burner provides a heat source temperature of between 1700 °C and 2000 °C. Thereby, the burner sprays a high-temperature airflow into the furnace to ensure the high temperature requirement required in the furnace, and when the furnace melts and flows along the gap between the high carbon spheres to the taphole, the airflow and the high carbon sphere The iron liquid acts as a superheating effect, so that the temperature of the finally flowing iron liquid can reach 1500 ° C or higher, and even the core power frequency induction electric furnace can no longer be arranged as the former furnace for the iron liquid heat preservation and heating.

In some embodiments, the heating source is disposed at least one row around the furnace body, and one row is evenly arranged with at least two, preferably 4-12 heating sources; when two rows of heating sources are provided, each row can be positive Arrange, set, or wait. Therefore, the heating source is arranged on the furnace body in an annular arrangement manner, which is convenient for heating the furnace body by inputting high-temperature airflow into the furnace in an all-round manner, and when two or more rows of heating sources are arranged inside the furnace body, the melting efficiency can be improved.

Specifically, when two rows of heating sources are arranged on the furnace body, the positive position means that a row of burners with the largest total power is placed in the lower row and a row of heat sources having the largest total power accounts for 70%-90% of the total power of all the heat sources. The equal power means that the total power of each row of burners is equal. Inversion means that a row of burners with the largest total power is placed in the upper row and the row of heat sources with the largest total power accounts for 70%-90% of the total power of all the heat sources; When the front is placed, the upper row of burners is 200-400mm from the top surface. When inverted, the upper row of burners is 400-700mm from the top surface, and the upper row of burners is 400-600mm from the top surface.

In some embodiments, there is further included at least one slag iron separator and at least one bridge, each of which is in communication with a slag separator via a bridge. Thereby, the molten iron and waste slag flow out of the furnace body through the tap hole, and then flow directly to the slag iron separator through the bridge, the molten iron continuously flows out, and the slag iron separator continuously filters the waste residue, so that the finally discharged molten iron Pure, slag-free, continuous iron production. Moreover, when there are two or more tapping ports and slag iron separators, it is convenient to repair and replace the refractory materials to achieve long-term continuous production.

In some embodiments, the natural gas burner is a high temperature burner having a natural gas-oxygen burner. Therefore, a natural gas-oxygen burner is used to ensure that the burner supplies high temperature gas of water vapor and carbon dioxide to the furnace without reducing gas, thereby reducing the loss of high carbon balls; and, by using a natural gas-oxygen burner. High temperature burners to ensure higher temperatures are provided into the furnace.

In some embodiments, a measurement system for determining a change in height of a high carbon ball is further included, wherein the measurement system is a mathematical calculation based on a relationship between a quantity of iron output, a material ratio, and a change in height of a high carbon ball. The model, or the charge melting position measuring instrument installed in the furnace body, wherein the measuring system can be modeled or purchased directly according to the prior art. Therefore, the remaining height of the high carbon ball can be monitored in real time through the measurement system, and the burning loss of the high carbon ball can be calculated through calculation and material analysis, so that it is convenient to control and understand the replenishment amount and the supplementary frequency of the high carbon ball to realize the cupola furnace. Stable operation and automation, intelligent control.

The novel coke-free cupola claimed in the present invention replaces the water-cooled grate and the refractory ball bed above the burner of the existing coke-free cupola burner, and replaces the high-carbon ball as a support column for carrying the metal charge It avoids the safety risk that the water-cooled grate may bring to the equipment, and also avoids the temperature loss of the molten iron droplets passing through the water-cooled grate and the heat loss taken by the cooling water in the water-cooled grate steel pipe. At the same time, replacing the refractory ball bed with high carbon ball not only reduces the slag in the melting process of the cupola, but also adds carbon to the molten iron droplets in the furnace, thus increasing the amount of scrap steel and low quality charge. , which reduces the cost of molten iron. Such a structural design not only reduces costs, reduces waste, but also smelts molten iron of higher quality.

According to another object of the present invention, there is provided a method of using the above-described novel coke-free cupola melting iron, the steps of which are as follows:

S1. loading a high carbon ball into the furnace body according to a preset height threshold, wherein the height threshold is a distance between a top surface of the stacked high carbon ball and the burner;

S2. Using natural gas burner burner ignition, preheating the inside of the furnace body for 1-2 hours;

S3. When the temperature in the furnace is at least 150 ° C higher than the melting point of the metal charge, the metal charge is charged into the furnace;

S4. Fused iron, continuous molten iron.

The method for utilizing the above-mentioned novel coke-free cupola melting iron disclosed in the invention is greatly simplified in the operation process and the control technology. Firstly, without burning coke, the limestone flux added to reduce the melting point of the coke ash is greatly reduced. Therefore, the amount of slag is also greatly reduced, which can further save energy and reduce the discharge of solid waste. Secondly, because of the high carbon ball, when the iron flows through the high carbon ball, the iron can be carbonized, and the iron is omitted. The liquid supplementation and recarburizer make the process optimization and operation easier; again, the elimination of the water-cooled grate and the ceramic ball hearth eliminates the inspection and repair of the grate steel pipe, optimizes the simplified operation and significantly improves the furnace opening. The safety of the work.

In some embodiments, a feeding step is further included, and the feeding step is specifically operated as follows:

According to the material ratio and the consumption rate of the high carbon ball, the batch filling time and time of the charge and the high carbon ball replenishing frequency and the replenishing amount are calculated in advance;

According to the high carbon ball replenishing frequency and the replenishing amount, when the charging material is replenished, a corresponding supplementary amount of high carbon balls is added to the furnace body. Therefore, the method disclosed in the present invention breaks through the technical defects that the ceramic ball consumption cannot be quantitatively calculated in the prior art, and the smelting process of the device can increase the loss amount, the loss rate and the addition amount of the high carbon ball. The calculation and control of the frequency provide conditions for the automation and intelligentization of the cupola, which greatly simplifies the operation process and control technology and greatly improves the production efficiency.

In some embodiments, the preset height threshold is 600-900 mm. The furnace body will be burned for 1-2 hours during the preheating process. Therefore, in consideration of the loss of the high carbon ball, in order to ensure that the top surface of the high carbon ball and the burner are kept at a distance of 400-700 mm when the metal charge is put into the furnace, the initial filling is performed. In the case of a high carbon ball, a height threshold (by calculation or empirical data) can be set according to the consumption of the high carbon ball, and the filling of the high carbon ball is performed according to the height threshold, so that when the metal charge is added and smelting During the process, the distance between the top surface of the high carbon ball and the burner is always maintained at 400-700 mm.

DRAWINGS

1 is a schematic cross-sectional structural view of a novel coke-free cupola according to an embodiment of the present invention;

Figure 2 is a schematic cross-sectional structural view of a new type of coke-free cupola shown in Figure 1 (partial structure not shown);

3 is a schematic cross-sectional structural view showing another state of use of the novel coke-free cupola shown in FIG. 1.

detailed description

The invention will now be described in further detail with reference to the accompanying drawings.

1 to 2 schematically show a specific embodiment of a novel coke-free cupola according to the present invention. As shown, in the present embodiment, the device comprises a furnace body 1, a heating source 2, a feeding port 6 placed at the top of the furnace body, a tap hole 7 placed at the bottom end of the furnace body, a slag iron separator 3 and a bridge 4,

Wherein, the furnace body 1 is vertically arranged, and in the non-working state, the whole body of the furnace body 1 is a cavity structure, which is vertically penetrated, and the furnace cylinder zone and the melting zone of the cavity structure are all arranged to accommodate the high carbon supporting the charge 8 a filling section 11 of the ball 5;

In the working state, the lower filling section 11 of the furnace body 1 is filled with a high carbon ball 5 which is in direct contact with the charge 8 and serves as a support charge 8;

The heating source 2 is a high-temperature burner having a natural gas-oxygen burner, and is provided with four, symmetrically distributed under the furnace body, and communicates with the filling section 11 below the furnace body 1 through the burner 21,

The burners 21 are correspondingly provided with four, symmetrically distributed under the furnace body 1, and communicate with the filling section 11 in which the high carbon balls 5 are placed, and both are inclined downward and directed toward the center of the furnace body 1, each burner 21 The power is 2.7MW, and the burner 21 supplies high temperature H ₂ O (water vapor) and CO _{2 at} 1900 ° C to the furnace body, so that the temperature of the finally flowing iron liquid can reach above 1450 ° C;

The taphole 7, the slag iron separator 3 and the bridge 4 are each provided, and the taphole 7 communicates with the slag separator 3 via the bridge 4, and the molten iron and the waste slag flow out of the furnace body through the taphole. The bridge flows to the slag iron separator, and the slag iron separator filters the waste residue, and the iron liquid continuously flows out from the slag iron separator. Among them, the melting rate of the coke-free cupola provided in this embodiment can reach 15 t / h.

In this embodiment, the high carbon sphere is a carbon sphere, and the diameter of the carbon sphere is 150-200 mm, and a gap is formed between the carbon sphere and the carbon sphere, on the one hand, the high-temperature gas circulation is facilitated, and on the other hand, the iron droplet is facilitated. The carbon spheres are dripped downward, and on the other hand, the iron liquid is carbonized during the dropping process; the carbon spheres are integrally formed by the column support, and the charge is maintained above the heating source 2.

In a specific practice, the charge added to the furnace is a metal charge, including pig iron, recycled charge and scrap; when the charge is pig iron, the amount of carbon ball replenished during the smelting process is appropriately reduced; and when the charge is scrap, The amount of carbon ball added will increase appropriately.

In this embodiment, the top surface 12 of the high carbon ball is higher than the burner 21 by a distance of not less than 600 mm.

In the present embodiment, a measurement system (not shown) for detecting a change in the height of the high carbon ball is further included, wherein the measurement system is based on a relationship between a melting rate, a temperature of the tapping iron, and a change in the height of the high carbon sphere. The established mathematical calculation model (which can be implemented with reference to the prior art cupola expert model) can determine the height change of the carbon ball support column in the coke-free cupola furnace through the tapping temperature and the melting rate; The burning amount of the high carbon ball is convenient for controlling the replenishing speed and the replenishing amount of the high carbon ball, so as to realize the stable operation, automation and intelligent control of the cupola furnace condition.

The temperature of the molten iron melted by the apparatus in this embodiment can be increased to 1500 ° C. Since the molten iron has low sulfur content and low oxygen content, the molten iron can be directly spheroidized in front of the furnace, and the main molten iron grade is QT400-18, QT500-7, HT200, HT250, etc., the annual base is 7000 hours (four shifts and three runs), and the annual molten iron is 100,000 tons.

The method of using the non-focus cupola melting iron, the steps are as follows:

S1: loading a plurality of carbon balls into the furnace body, the carbon balls are directly in contact with the charge and serve as a load-bearing column of the charge, and the top surface height of the carbon balls exceeds 600-900 mm of the natural gas burner burner;

S2: Open the furnace, ignite the natural gas-oxygen burner of the natural gas burner, and keep the temperature of the burner at 1700 °C-2000 °C by introducing oxygen, and keep the length of 1-2h. At this time, the burner is sprayed into the furnace. High temperature H ₂ O (water vapor) and CO ₂ , the high temperature gas preheats the inside of the furnace while flowing upward, and heats the carbon ball;

S3: when the temperature in the furnace is at least 150 ° C higher than the melting point of the metal charge, the charge is put into the furnace through the feeding port, and the top surface of the charge is kept at the lower edge of the feeding port during the whole opening process;

S4: As the ambient temperature of the furnace rises and the high-temperature gas flows upward, the charge is heated to gradually melt and fall, and the molten iron is continuously discharged. The molten iron droplets fall along the gap between the carbon balls during the falling process. , further heated (ie, superheated) by the high temperature gas and the carbon ball to make the temperature of the molten iron flow out to meet the requirements, and the carbon ball is a substance having a high carbon content, and the iron droplet can increase carbon when passing through the carbon ball;

S5: With the melting of the charge, it is necessary to appropriately increase the high carbon ball with a small amount of supplement according to the feeding of the charge, wherein the supplement of the high carbon ball can be realized by pre-calculating the charge according to the material ratio and the consumption rate of the high carbon ball. The filling batch and time as well as the high carbon ball replenishing frequency and replenishing amount, according to the high carbon ball replenishing frequency and the replenishing amount, add a corresponding supplementary amount of high carbon ball to the furnace body when replenishing the charging material.

The high-temperature gas injected into the furnace by the burner does not contain oxygen, and the carbon ball is dense and non-porous, and the reactivity is very low, so high-temperature H ₂ O (water vapor) and CO ₂ do not undergo oxidation-reduction with a large amount. The reaction is only when the high-temperature iron liquid flows through the gap of the carbon ball, which will increase the carbon and cause a small loss. Therefore, the consumption of the high-carbon ball can be quantitatively calculated, so that a small amount of carbon can be appropriately added to the metal charge as needed. Prime ball.

Fig. 3 schematically shows a specific embodiment of another novel coke-free cupola implemented in accordance with the present invention.

As shown in the figure, the difference from the embodiment shown in FIG. 2 is that in the embodiment shown in FIG. 3, the heating source 2 is a natural gas burner, and two rows are arranged around the furnace body 1, and four rows are arranged in each row. And symmetrically distributed under the furnace body 1, the two rows of heating sources 2 are arranged in an equal manner, wherein the heating source and the heating source are independently arranged, and each row is also independently arranged, and the burners of the upper row of the heating source 2 are arranged independently. The distance from the top surface 12 is 400-600 mm, and the distance between the burners 21 of the lower row of heat sources is 500-700 mm from the top surface 12.

Wherein, the burners 21 of each row of the heating source 2 are placed in the lower part of the furnace body 1, and the corresponding areas of the burners 21 are filled with high carbon balls 5; the power of each burner 21 is 2.7 MW, and the total power of each row The ratio is 10.8 MW, and the total power of all the heating sources is 21.6 MW. The melting rate of the coke-free cupola provided in this embodiment can reach 30 t/h.

In the embodiment shown in FIG. 3, the new tapless cupola has two iron taps, a slag iron separator and a bridge, two of which are arranged adjacent to each other, and can be opened only during normal production. Run one set of taphole and slag iron separators, and the other set is reserved; because the refractory in the slag iron separator needs to be repaired after a long time of use, at this time, the alternate taphole and slag iron can be switched The separator is serviced to ensure continuous production.

In the embodiment shown in Figure 3, the high carbon spheres 5 are carbon spheres and a small amount of waste graphite electrode dicing.

What has been described above is only some embodiments of the invention. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and scope of the invention.

Claims

A novel coke-free cupola, characterized in that it comprises a furnace body (1) and a heating source (2),

The inside of the furnace body (1) is a hollow structure which is vertically penetrated, and the furnace body (1) is provided with a feeding port (6) and at least one tapping port (7), the feeding port (6) and the tapping iron a port (7) is connected through the cavity structure, wherein

The furnace zone and the melting zone of the cavity structure are each arranged to receive a filling section (11) of the high carbon ball (5) supporting the charge (8),

The heating source (2) is a natural gas burner, and the burner (21) of the natural gas burner is disposed on the furnace body (1) and is located in the filling section (11) of the high carbon ball (5).
A novel coke-free cupola according to claim 1, characterized in that the filled high carbon ball (5) is a carbon ball and/or graphite electrode cut.
A novel coke-free cupola according to claim 2, characterized in that the top surface (12) of the filled high carbon ball (5) is 400-700 mm above the burner (21).
A novel coke-free cupola according to claim 3, characterized in that the burner (21) provides a heat source temperature of from 1700 °C to 2000 °C.
The novel coke-free cupola according to claim 1, characterized in that the heating source (2) is arranged at least one row around the furnace body (1), and at least two heating sources are evenly arranged in each row (2) .
A novel coke-free cupola according to claim 5, characterized in that, when two rows of heating sources (2) are provided, each row is arranged in an upright, inverted or equal manner.
A novel coke-free cupola according to any of claims 1-6, characterized in that it further comprises at least one slag iron separator (3) and at least one bridge (4), each tapping port (7) They are each connected to a slag iron separator (3) via a bridge (4).
A novel coke-free cupola according to claim 7, wherein said natural gas burner is a high temperature burner having a natural gas-oxygen burner.
A method of using the coke-free cupola melting iron of claim 1 wherein the steps are as follows:

S1. Loading a high carbon ball into the furnace body according to a preset height threshold, wherein the height threshold is a distance between a top surface of the stacked high carbon ball and the burner;

S2. Using a natural gas burner burner to preheat the inside of the furnace;

S3. When the temperature in the furnace is at least 150 ° C higher than the melting point of the metal charge, the metal charge is charged into the furnace;

S4. Fused iron, continuous molten iron.
The method of claim 9 further comprising the step of feeding, said step of feeding comprising:

According to the material ratio and the consumption rate of the high carbon ball, the batch filling time and time of the charge and the high carbon ball replenishing frequency and the replenishing amount are calculated in advance;

According to the high carbon ball replenishing frequency and the replenishing amount, when the charging material is replenished, a corresponding supplementary amount of high carbon balls is added to the furnace body.
The method of claim 9 or 10, wherein the predetermined height threshold is 600-900 mm.