Oxy-fuel burner, ignition and flame control system and method of controlling ignition and flame

Abstract

An oxy-fuel burner (1) and its use are disclosed, the oxy-fuel burner (1) comprising a housing (2) defining an oxidizer supply channel (3) extending in a longitudinal direction to a downstream end of the housing, a fuel supply channel (5) extending likewise in the longitudinal direction of the housing, and an oxidizing medium injector (4) extending in the longitudinal direction inside the fuel supply channel (5) and an ignition and flame control electrode (6) inside the oxidizer supply channel (3), the ignition and flame control electrode (6) being designed to provide initial ignition and subsequent flame control of the oxy-fuel burner (1) and being connectable to a system for automatic control of the oxy-fuel burner ignition and flame control.

Description

TECHNICAL FIELD

[0001] The present invention relates to an oxy-fuel burner for smelting furnaces, in particular to an oxy-fuel burner suitable for use in a shaft furnace for the production of mineral wool and its use. The present invention also relates to a system and method for controlling the ignition and flame control of such an oxy-fuel burner. BACKGROUND

[0002] The mineral wool production process comprises obtaining a raw material melt (for example basalt or dolomite) and subsequently converting the melt into fibres, which are then typically used to form mineral wool sheets. The melt is obtained by melting the raw material in a special shaft furnace (a cupola). Coke is used as fuel for the shaft furnace, which is mixed with the charge and loaded into the furnace. Oxygen present in the air acts as the oxidizing agent necessary for the combustion process, which is supplied through tuyeres located on the side walls of the furnace.

[0003] The price of coke is relatively high. Furthermore, in certain geographical areas there are no available deposits of coking coal, or the local coke does not always meet the required quality, which forces mineral wool manufacturers to purchase coke from abroad. In this case, the cost of this type of fuel represents a significant part of the costs required for the production of mineral wool.

[0004] One of the known methods for reducing the costs associated with the production of mineral wool using a cupola furnace is to increase the oxygen content in the air stream supplied to the furnace - the oxygen-enhanced technology. The technology involves supplying oxygen into the main air stream supplied to the furnace, or directly into each tuyere, and in particular enables increasing the rate of melting of the raw material and reducing coke consumption and the amount of exhaust gases. The oxygen-enhanced technology is described, for example, in the document "Oxygen-enhanced combustion", edited by Charles E. Baukal, Jr., CRC Press, 1998.

[0005] However, when using the technology, expensive coke remains the main fuel used in the process of producing mineral wool.

[0006] Another solution for reducing coke consumption involves partially replacing the coke with a cheaper fuel, such as natural gas. Thus, in hot blast cupolas for the production of cast iron, a technology has been successfully used in which "natural gas-oxygen" gas-oxygen burners are installed directly into or above the tuyeres to replace a part of the energy obtained due to the combustion of coke with the energy produced by the combustion of a mixture of natural gas and oxygen. Generally, this method reduces coke consumption by up to 10% and increases the melting rate and the percentage of hydrogen in the exhaust gases. At the same time, the installation of the burners above the tuyeres requires a complex redesign of the furnace.

[0007] For example, a design of a gas-oxygen burner that can be installed in the wall of an iron smelting furnace is known from document / 2 / US 6089858, publication date 18 July 2000. This burner has an upstream end and a downstream end and comprises a housing extending in a longitudinal direction and defining an oxidant supply channel extending to the downstream end of the burner and opening into an oxidant outlet port at the downstream end, and a plurality of fuel supply channels extending in said longitudinal direction and inside the oxidant supply channel, each of which opens at the downstream end of the burner.

[0008] However, said document does not contain any information about the possibility of using such a burner in a shaft furnace, in particular in a shaft furnace for the production of mineral wool.

[0009] Another similar solution is described in document / 3 / US 2010 / 0186552, publication date 29 July 2010, and relates to a shaft furnace for melting raw materials, in particular a cupola. The furnace is heated using the combustion of solid fuel, with the additional supply of injection gas containing 21% oxygen to the furnace. The furnace is also heated by at least one burner to which gaseous or liquid fuel and gaseous oxidant are supplied. Although the above document relates to a furnace for the production of cast iron, said document mentions the possibility of additionally using the technical solution disclosed therein in a furnace for the production of mineral wool. Thus, the indicated document proposes a solution that represents a combination of oxygen enhancement technology and the use of oxygen-fuel burners to replace part of the energy obtained from the combustion of coke with energy produced from the combustion of cheaper fuel. However, said document proposes to equip the tuyeres of the furnace alternately with oxygen injectors or oxygen-fuel burners, which would require complex work to equip the tuyeres with one or the other of the mentioned devices.

[0010] Furthermore, the total number of burners / injectors with which the furnace can be equipped represents half the number of tuyeres of the furnace, thus reducing the flexibility of the production process compared to a furnace in which the number of burners / injectors used is equal to the number of tuyeres.

[0011] It is also worth noting that the above document does not contain any information about equipping the burners with automatic ignition and flame control devices, the inclusion of which would enable the efficiency of the shaft furnace to be increased and which is important in ensuring the safe operation of the shaft furnace.

[0012] Devices for automatic ignition and flame control for burners are known per se from the prior art. For example, such devices are described in the document / 4 / “Pribory kontrolya plameni i upravleniya rozzhigom” / / URL: https: / / www.promav.ru / production / pribory-kontrolya-plameni-i-upravlenie-rozzhigom / (accessed on November 12, 2020).

[0013] At the same time, there is a need for further development of a technology that would combine the benefits of using oxygen-fuel burners and oxygen enhancement in smelting furnaces, thus providing further savings in solid fuel with reduced labor costs, improving the quality of the final product, increasing the production capacity, cost-effectiveness, environmental compatibility and safety of smelting furnaces, in particular, of shaft furnaces for the manufacture of mineral wool, while maintaining high quality of the final product. SUMMARY

[0014] Based on the above, the present invention is focused on creating a technical solution that would combine the benefits of using oxygen-fuel burners and oxygen enhancement, making it possible to provide further savings in solid fuel with reduced labor costs and improve the quality of the final product, increase the production capacity, flexibility, environmental compatibility and safety of the process of operating a shaft furnace, in particular, a furnace for the manufacture of mineral wool.

[0015] To solve the stated technical problem, according to one aspect of the present invention, an oxygen-fuel burner is proposed, which is designed to be able to

[0016] (i.e. adapted to or adapted for) be housed within the walls of a smelting furnace and comprises:

[0017] a housing defining an oxidant supply channel extending in a longitudinal direction from an upstream end of the housing to a downstream end and having an outlet port (i.e. an oxidant outlet port) at the downstream end of the housing;

[0018] a fuel supply channel extending in the longitudinal direction of the housing, an outlet port (i.e. a fuel outlet port) of the fuel supply channel being located at the downstream end of the housing; and

[0019] an oxidizing medium injector extending in the longitudinal direction inside the fuel supply channel, the outlet port of the oxidizing medium injector, i.e. the oxidizing medium outlet port, being located at the downstream end of the housing; and an ignition and flame control electrode extending inside the oxidant supply channel and designed to provide initial ignition and subsequent flame control of the oxy-fuel burner, wherein said ignition and flame control electrode is designed to be connected to a system for automatically controlling ignition and flame control of the oxy-fuel burner.

[0020] The proposed oxy-fuel burner can be installed into each tuyere of the smelting furnace. Since each oxy-fuel burner contains an oxidizing medium injector, the number of oxy-fuel burners and oxidizing medium injectors installed in the furnace in the present invention exceeds twice the number of oxy-fuel burners and oxidizing medium injectors of the solution with oxy-fuel burners and injectors alternately equipped with the tuyeres of the furnace, which makes it possible to improve the flexibility of controlling the mineral wool manufacturing process and to obtain a more uniform distribution of thermal energy around the periphery of the furnace. Moreover, the time spent on performing the work related to equipping the furnace with the same type of oxy-fuel burners is less than the time required for equipping the furnace with different devices (oxy-fuel burners and injectors).

[0021] Furthermore, the fact that the oxidizing medium injector is installed inside the oxy-fuel burner enables the oxy-fuel burner to change the pulsation of the oxy-fuel burner flame, so that the thermal energy is delivered to the center of the melt, thus ensuring temperature uniformity over the entire area of the melt, which is essential for obtaining a high-quality final product during the melting of the raw material.

[0022] The presence of the automatic ignition and flame control device makes it possible to improve the safety level of the oxy-fuel burner and the furnace as a whole. During the operation of the oxy-fuel burner without the automatic ignition and flame control device, it is possible to have "flame-outs", i.e. the injection of fuel and oxidant / oxidizing medium without combustion, which can lead to emergency situations and damage to the equipment.

[0023] The use of the automatic ignition and flame control device makes it possible to eliminate said phenomenon. Based on the results of the tests carried out by the inventor, it was found that when using natural gas as fuel, the use of the automatic ignition and flame control device in the shaft furnace according to the present invention makes it possible to achieve a 30% replacement of traditional fuel (e.g. coke) with natural gas and a 10% increase in the production capacity of the furnace. Therefore, the equipping of the shaft furnace with the oxy-fuel burner according to the present invention makes it possible to replace a large part of the expensive coke with another, cheaper type of fuel.

[0024] Furthermore, the use of the oxy-fuel burner according to the present invention makes it possible to reduce the amount of harmful emissions during the operation of the furnace.

[0025] According to an embodiment of the present application, the ignition and flame control electrode is an ionization electrode.

[0026] According to an embodiment of the present application, the oxidizing medium injector is designed to be able to supply the oxidizing medium at subsonic speed.

[0027] According to an embodiment of the present application, the oxidizing medium injector is designed to be able to supply the oxidizing medium at supersonic speed.

[0028] According to an embodiment of the present application, the oxidizing medium injector is equipped with a de Laval nozzle.

[0029] In the present context, the terms "oxidizing medium" and "oxidizer" both refer to a combustion oxidizing medium, such as air, oxygen-enriched air or oxygen. The term "oxidizer" is used for the combustion oxidizing medium supplied via the oxidizer supply channel defined by the oxygen-fuel burner housing. The term "oxidizing medium" is used for the combustion oxidizing medium supplied via the oxidizing medium injector, which extends in the longitudinal direction of the housing in the fuel supply channel.

[0030] According to a preferred embodiment of the present application, the concentration of oxygen in the oxidizing medium introduced by the oxidizing medium injector is higher than the concentration of oxygen in the oxidizer introduced by the oxidizer supply channel.

[0031] According to an embodiment of the present application, the fuel is natural gas.

[0032] According to an embodiment of the present application, the oxygen-fuel burner comprises a ground electrode positioned at a distance of 3 mm to 4 mm from the ignition and flame control electrode in the transversal direction of the oxygen-fuel burner, wherein the ground electrode as well as the downstream end of the ignition and flame control electrode are positioned at equal distances from the downstream end of the housing of the oxygen-fuel burner.

[0033] According to an embodiment of the present application, the distance from the downstream end of the oxidizing medium injector to the downstream end of the housing of the oxygen-fuel burner is equal to the outer diameter d of the oxidizing medium injector, while the distance from the downstream end of the ignition and flame control electrode to the downstream end of the housing of the oxygen-fuel burner is equal to 0.5d.

[0034] According to an embodiment of the present application, the oxygen-fuel burner is designed to be able to be installed into a tuyere located in a wall of a smelting furnace, wherein the distance from the downstream end of the housing of the oxygen-fuel burner to the downstream end of the tuyere is between 2D and 3D, wherein D is the inner diameter of the tuyere.

[0035] According to an embodiment of the present application, the oxygen-fuel burner is designed to be able to be installed into a tuyere having an inner diameter of 700-1,200 m 3in the tuyere of a blast supply flow of 100-300 m3 / hr.

[0036] According to another aspect of the present application, there is presented a system for controlling ignition and flame control of the above-described oxy-fuel burners. The system comprises: an ignition device; a combustion signal transmission device; a shut-off valve unit designed to be connectable to a gas-oxygen unit that regulates and supplies the flow of fuel, oxidizer / oxidizing medium and instrument air to the oxy-fuel burners; and a control unit designed to be in communication with the gas-oxygen unit, the ignition device, the combustion signal transmission device and the shut-off valve unit.

[0037] According to an embodiment of the present application, the ignition device is a high-voltage transformer source.

[0038] According to a third aspect of the present application, there is presented a method for controlling ignition and flame control of oxy-fuel burners installed in a smelting furnace using the above-described system, the method comprising the steps of:

[0039] - receiving a signal confirming that the gas-oxygen unit has been turned on;

[0040] - determining the number of oxy-fuel burners that need to be put into operation;

[0041] - opening the shut-off valves in the shut-off valve unit to supply fuel and oxidizer / oxidizing medium to the selected oxy-fuel burners;

[0042] - turning on spark ignition of the selected oxy-fuel burners;

[0043] - turning off the spark ignition;

[0044] - monitoring the flame in the oxy-fuel burners, during which monitoring:

[0045] determining whether a flame is present in each of the oxy-fuel burners, wherein, when a flame is found to be present in all of the oxy-fuel burners,

[0046] the operation is continued, but if a flame is found not to be present in one or more of the oxy-fuel burners, spark ignition is turned on in the corresponding oxy-fuel burners;

[0047] - maintaining a record of the number of unsuccessful attempts to ignite the oxy-fuel burners, wherein, if said number is greater than a specified value, the supply of gas and oxidizer / oxidizing medium to the relevant oxy-fuel burners is stopped.

[0048] According to an embodiment of the present application, the specified value of the number of unsuccessful attempts to ignite the oxy-fuel burners is equal to five. BRIEF DESCRIPTION OF DRAWINGS

[0049] The invention will now be described in more detail with reference to the accompanying drawings, in which:

[0050] - [ Figure 1 A longitudinal section of an oxygen-fuel burner for a smelting furnace according to the present invention is shown schematically.

[0051] - [ Figure 2 The diagram shows a functional block diagram of a system for controlling the ignition and flame control of an oxygen-fuel burner according to the present invention. Detailed Implementation

[0052] [ Figure 1 A longitudinal section of an oxygen-fuel burner 1 according to a first aspect of the invention is shown in schematic form.

[0053] The oxygen-fuel burner 1 is designed to be installed in the tuyeres of a smelting furnace, particularly a vertical shaft furnace used for manufacturing mineral wool.

[0054] The oxy-fuel burner 1 has an upstream end and a downstream end and includes a housing 2 extending along the longitudinal direction of the oxy-fuel burner.

[0055] The oxygen-fuel burner 1 according to the present invention includes two channels for supplying oxidant—an oxidant supply channel 3 and a channel formed by an oxidizing medium injector 4. The oxidant supply channel 3 is cylindrical in shape, formed by the housing 2 of the oxygen-fuel burner, and extends from the upstream end of the oxygen-fuel burner to the downstream end, leading to the oxidant outlet port at the downstream end of the housing.

[0056] The oxygen-fuel burner 1 also includes a fuel supply passage 5 extending in the longitudinal direction shown inside the oxidant supply passage 3.

[0057] The fuel used in an oxygen-fuel burner can be any suitable liquid or gaseous hydrocarbon fuel, such as natural gas.

[0058] According to the present invention, the oxidizing medium injector 4 extends longitudinally inside the fuel supply channel 5 and has an outlet port located at the downstream end of the housing.

[0059] The ignition and flame control electrode 6 is located inside the oxidant supply channel 3, and the electrode is used for the initial ignition and subsequent flame control of the oxygen-fuel burner 1.

[0060] The electrode can be, for example, an ionization electrode.

[0061] The aforementioned ignition and flame control electrodes are designed to be connected to a system for the automatic control of ignition and flame control of an oxygen-fuel burner, which is described below.

[0062] The oxidizing medium injector 4 is designed to be able to supply the oxidizing medium at subsonic or supersonic speed and can be equipped with a Laval nozzle.

[0063] The oxy-fuel burner can also comprise a grounding electrode (not shown in the figures) which is preferably positioned at a distance of 3 mm to 4 mm from the ignition and flame control electrode 6 along the transversal direction of the oxy-fuel burner, wherein the grounding electrode as well as the downstream end of the ignition and flame control electrode 6 are positioned at an equal distance from the downstream end of the housing 2 of the oxy-fuel burner. Furthermore, the distance LI from the downstream end of the oxidizing medium injector 4 to the downstream end of the housing 2 of the oxy-fuel burner is preferably equal to the outer diameter d of the oxidizing medium injector 4, while the distance L2 from the downstream end of the ignition and flame control electrode 6 to the downstream end of the housing 2 of the oxy-fuel burner is equal to 0.5d. The indicated distances are required to be such values to ensure reliable ignition of the oxy-fuel burner and to reduce the possibility of non-ignition.

[0064] The components of the proposed oxy-fuel burner 1 are manufactured from materials conventionally used in the technical field for the manufacture of oxy-fuel burners and which ensure the necessary level of heat resistance. The oxy-fuel burner 1 can have any type of cooling system (using air, water or another medium as coolant). However, it is important that the dimensions of the cooling system do not increase the diameter of the oxy-fuel burner 1 beyond the required limits. In general, the outer diameter of the oxy-fuel burner 1 must not exceed one third of the diameter of the tuyere (not shown in the figures) in which the oxy-fuel burner is installed.

[0065] Furthermore, the downstream end of the housing 2 of the oxy-fuel burner is preferably installed at a distance of between 2D and 3D from the downstream end of the tuyere, where D is the internal diameter of the tuyere. The indicated distance is chosen in order to ensure trouble-free operation of the device. If the oxy-fuel burner is positioned at a smaller distance, i.e. too close to the melt zone, there is a risk that the melt will enter the oxy-fuel burner, while positioning the oxy-fuel burner too far from the melt zone will result in insufficient heating of the melt and overheating of the tuyere in the operating zone. Preferably, the blast is supplied to the tuyere at a flow rate of 700-1,200 m3 / hr and a temperature of 250-650°C. The indicated blast parameters are determined by the specific characteristics of the production process used in the present invention for melting raw materials in a smelting furnace (specifically, the process providing combustion of natural gas in oxygen) and by the specific design characteristics of the smelting furnace. 3 / hr and a temperature of 250-650°C. The indicated blast parameters are determined by the specific characteristics of the production process used in the present invention for melting raw materials in a smelting furnace (specifically, the process providing combustion of natural gas in oxygen) and by the specific design characteristics of the smelting furnace.

[0066] The design of the oxy-fuel burner 1 is such that the oxy-fuel burner is able to operate in four different operating modes.

[0067] In the first operating mode, no oxidizing medium is supplied through the oxidizing medium injector 4. Only the oxidizer supply channel 3 and the fuel supply channel 5 of the oxy-fuel burner are in operation.

[0068] In the second operating mode, a specified amount of oxidizing medium is supplied at subsonic speed through the oxidizing medium injector 4, the remaining amount of oxygen being supplied via the oxidizer supplied through the oxidizer supply channel 3.

[0069] In the third operating mode, most of the oxygen is supplied as oxidizer, which passes through the oxidizer supply channel 3, while a smaller amount of oxygen is supplied via the oxidizing medium supplied at subsonic speed through the oxidizing medium injector 4.

[0070] In the fourth operating mode, the oxidizing medium is supplied at supersonic speed through the oxidizing medium injector 4, so as to achieve maximum penetration of the oxidizing medium into the melt present in the furnace.

[0071] The oxy-fuel burner 1 according to the present application is designed to be installed into the tuyeres of a smelting furnace. The furnace equipped with such an oxy-fuel burner 1 has two sources of energy required for melting the raw materials. One part of the energy is the energy obtained due to the combustion of solid fuel (coke), while the other part is the energy produced by the combustion of the mixture of liquid or gaseous fuel with oxygen present in the oxidizer / oxidizing medium.

[0072] Controlling the distribution of energy between the two sources of energy and the amount of energy obtained by the oxy-fuel burner in each tuyere will enable to increase the production capacity and ensure the operational flexibility and operational safety of the shaft furnace.

[0073] A pressure sensor can be installed in each tuyere of the furnace. Such a pressure sensor can be installed, for example, in the forward area of the tuyere upstream of the oxy-fuel burner. The positioning of the sensor can vary depending on the design of the furnace, as long as the sensor is able to perform the functions described below. Controlling the distribution of the total fuel flow to the individual oxy-fuel burners can be performed by adjusting the air pressure in the tuyere in which the oxy-fuel burner is installed. Thus, if a blockage occurs due to the obstruction of the area upstream of the oxy-fuel burner by solid material, the sensor will record a decrease in pressure, and the power of the oxy-fuel burner is increased to melt the solid material and eliminate the obstruction.

[0074] For example, if a blockage occurs upstream of the tuyere, between 1 / 10 and 1 / 3 of the total amount of oxygen can be supplied through the above-described oxidizing medium injector 4 to increase the pulsation of the flame and ensure the penetration of heat to the center of the furnace. In fact, the oxidizing medium injector 4 acts as an oxidizing medium lance.

[0075] Furthermore, the fuel supply in the fuel supply channel 5 to the oxy-fuel burner can be controlled using parameters such as the melt temperature and the temperature inside the furnace, the temperature of the exhaust gases, or the temperature of the water in the cooling circuit.

[0076] The total heat output of the oxy-fuel burners can be regulated by adjusting the flow of fuel, the flow of oxidant supplied through the oxidant supply channel 3, and the flow of oxidizing medium through the oxidizing medium injector 4 and by adjusting the number of oxy-fuel burners in operation.

[0077] The total heat output generated by the oxy-fuel burners 1 can be distributed evenly among all the oxy-fuel burners 1. Also, in order to maintain the most efficient flame penetration into the furnace, some of the oxy-fuel burners 1 can be turned off.

[0078] Controlling the sequence in which the oxy-fuel burners are turned on and the output of the oxy-fuel burners to ensure that heat is transferred uniformly into the melt can be done using appropriate programs.

[0079] The composition of the furnace charge, the quality of the coke, and the amount of liquid or gaseous fuel and the amount and concentration of oxygen in the oxidant / oxidizing medium will affect the amount of steam and the overall composition of the exhaust gases. An increase in the concentration of carbon monoxide and hydrogen will cause post-combustion and overheating at the furnace outlet. In order to mitigate the defects, the oxy-fuel burner flames are increased and decreased by adjusting the supply of fuel and oxidant / oxidizing medium.

[0080] The present invention enables more than 30% of the energy obtained from the combustion of coke to be replaced with energy obtained from the combustion of another fuel without significantly changing the melting process and the composition of the fumes.

[0081] Controlling the ignition and flame control of the oxy-fuel burners is done by a system for controlling the ignition and flame control of the oxy-fuel burners 1 installed in each tuyere of the furnace in which the melt of the raw material, in particular the raw material for the manufacture of mineral wool, is produced. The functional block diagram of the above-mentioned system is shown in Figure 2 ] as shown.

[0082] The above-mentioned system comprises an ignition device (ID), a combustion signal delivery device (CSD), a control unit (CU), and a shut-off valve unit (CVU) which can be connected to a gas-oxygen unit (GOU) designed to automatically or semi-automatically regulate the flow of fuel, oxidant / oxidizing medium, and instrument air for supplying the fuel, oxidant / oxidizing medium, and instrument air to the oxy-fuel burners at a specified pressure, flow, and ratio of one gas to another.

[0083] The gas-oxygen unit comprises fuel, gaseous oxidant and instrument air pipes mounted on the frame, as well as technical devices and pipe fittings, including fuel and oxidant regulating valves mounted in series in the pipes.

[0084] The outlets of the fuel and gaseous oxidant pipes are connected via the shut-off valve unit to the corresponding valves of the oxy-fuel burner 1, specifically to the fuel passage 5 and the oxidant supply passage 3.

[0085] The inlet of the fuel pipe of the gas-oxygen unit is connected to a fuel source. The inlet of the gaseous oxygen pipe is connected to an oxidant source, such as a blower.

[0086] The inlet of the pipe supplying the oxidizing medium to the oxidizing medium injector 4 is connected to a separate oxidant source (SOA), for example to an air source with an oxygen content of more than 21%.

[0087] The ignition device can be a high-voltage transformer source, the design of which is known per se.

[0088] For example, the LUCh-KE flame sensor manufactured by the NPP Proma company can be used as the combustion signal transmission device.

[0089] The control unit comprises a programmable logic controller designed to send control signals to the gas-oxygen unit, the shut-off valve unit and the ignition device, and to receive signals from the combustion signal transmission device and the gas-oxygen unit. The control unit also controls the supply of the oxidizing medium to the oxidizing medium injector 4.

[0090] The control unit controls each individual oxy-fuel burner and coordinates the overall operation of all oxy-fuel burners installed in the furnace.

[0091] Each oxy-fuel burner installed in the smelting furnace is equipped with the above-mentioned ignition and flame control system.

[0092] The use of the ignition and flame control system to control the ignition and flame control of the oxy-fuel burners installed in the smelting furnace is carried out according to the following algorithm.

[0093] The start-up of the system takes place once a signal has been received confirming that the gas-oxygen unit has been turned on. Once such a signal has been received, the number of oxy-fuel burners among all the oxy-fuel burners installed in the furnace tuyeres that need to be activated is determined, and the shut-off valves of the corresponding oxy-fuel burners are opened in the shut-off valve unit in order to supply the selected oxy-fuel burners with fuel and oxidant / oxidizing medium.

[0094] After that, the spark ignition of the selected oxy-fuel burner is switched on. To achieve this, the control unit sends a signal to the ignition device of the selected oxy-fuel burner to switch on the ignition, after which the ignition device causes a spark between the ignition and flame control electrodes and the housing of the oxy-fuel burner, which results in the combustion of the fuel-air mixture. The principle of spark ignition using, for example, a high-voltage source and ionization electrodes is well known and is not studied in detail in the present application.

[0095] After a certain period of time, the duration of which can be, for example, approximately 3 seconds, the spark ignition is switched off and the flame is controlled.

[0096] The flame control is also performed using the ionization electrodes of the oxy-fuel burner. The principle of using ionization electrodes to control the flame is also known to the person skilled in the art.

[0097] The signal from the ionization electrodes is received by the combustion signal transmission device, which in turn signals the unit controlling the ignition and the shut-off valve unit.

[0098] As part of the flame control process, the flame in each oxy-fuel burner is monitored. If a flame is found in all of the oxy-fuel burners, the operation continues.

[0099] If there is no flame in any of the oxy-fuel burners, the shut-off valve of that oxy-fuel burner is closed briefly and then reopened, switching on the spark ignition of that oxy-fuel burner by transmitting a corresponding signal to the ignition device of that oxy-fuel burner.

[0100] During the implementation of the method, a record is maintained of unsuccessful attempts to light each oxy-fuel burner, wherein, if the number of unsuccessful attempts exceeds a specified value, the supply of gas and oxidant / oxidizing medium is stopped by closing the shut-off valve in response to a signal transmitted by the control device to the shut-off valve unit.

[0101] The number of unsuccessful attempts can be equal to, for example, five.

[0102] The technical solution provided by the present application therefore combines the benefits of using oxy-fuel burners and oxygen enrichment, making it possible to increase the savings in solid fuels and improve the quality of the end product at lower labor costs, increasing the production capacity, flexibility, environmental compatibility and safety of the process for controlling the operation of a shaft furnace, in particular a furnace for the manufacture of mineral wool.

[0103] Explanation of abbreviations:

[0104]

Claims

1. An oxy-fuel burner (1) adapted to be housed within the wall of a smelting furnace, the oxy-fuel burner (1) comprising: A housing (2) defining an oxidant supply channel (3) extending longitudinally from an upstream end to a downstream end of the housing (2) and having an oxidant outlet port at the downstream end of the housing (2). A fuel supply channel (5) extends along the longitudinal direction of the housing (2) and has a fuel outlet port located at the downstream end of the housing (2). An oxidizing medium injector (4) extends longitudinally within the fuel supply channel (5) and has an oxidizing medium outlet port located at the downstream end of the housing (2). Ignition and flame control electrode (6), which extends inside the oxidant supply channel (3) and is adapted to provide initial ignition of the oxygen-fuel burner (1) and subsequent control of the oxygen-fuel burner flame, wherein the ignition and flame control electrode (6) is adapted to be connected to a system for automatically controlling the ignition and flame control of the oxygen-fuel burner.

2. The oxygen-fuel burner (1) according to claim 1, wherein, The ignition and flame control electrode (6) is an ionization electrode.

3. The oxygen-fuel burner (1) according to claim 1, wherein, The oxidizing medium injector (4) is adapted to supply the oxidizing medium at a subsonic speed.

4. The oxygen-fuel burner (1) according to claim 2, wherein, The oxidizing medium injector (4) is adapted to supply the oxidizing medium at a subsonic speed.

5. The oxygen-fuel burner (1) according to claim 1, wherein, The oxidizing medium injector is adapted to supply the oxidizing medium at supersonic speeds.

6. The oxygen-fuel burner (1) according to claim 2, wherein, The oxidizing medium injector is adapted to supply the oxidizing medium at supersonic speeds.

7. The oxygen-fuel burner according to claim 5, wherein, The oxidizing medium injector (4) is equipped with a Laval nozzle.

8. The oxygen-fuel burner according to claim 6, wherein, The oxidizing medium injector (4) is equipped with a Laval nozzle.

9. The oxygen-fuel burner according to any one of claims 1 to 8, wherein, The concentration of oxygen in the oxidizing medium introduced through the oxidizing medium injector (4) is higher than the concentration of oxygen in the oxidant introduced through the oxidant supply channel (3).

10. The oxygen-fuel burner according to any one of claims 1 to 8, wherein, The fuel is natural gas.

11. The oxygen-fuel burner according to claim 9, wherein, The fuel is natural gas.

12. The oxy-fuel burner according to any one of claims 1 to 8, wherein the oxy-fuel burner includes a grounding electrode positioned laterally at a distance of 3 mm to 4 mm from the ignition and flame control electrode (6), wherein, The downstream ends of the grounding electrode and the ignition and flame control electrode (6) are positioned at a distance equal to the downstream end of the housing (2) of the oxygen-fuel burner.

13. The oxy-fuel burner according to claim 9, wherein the oxy-fuel burner includes a grounding electrode positioned laterally at a distance of 3 mm to 4 mm from the ignition and flame control electrode (6), wherein, The downstream ends of the grounding electrode and the ignition and flame control electrode (6) are positioned at a distance equal to the downstream end of the housing (2) of the oxygen-fuel burner.

14. The oxy-fuel burner according to claim 10, wherein the oxy-fuel burner includes a grounding electrode positioned laterally at a distance of 3 mm to 4 mm from the ignition and flame control electrode (6), wherein, The downstream ends of the grounding electrode and the ignition and flame control electrode (6) are positioned at a distance equal to the downstream end of the housing (2) of the oxygen-fuel burner.

15. The oxygen-fuel burner according to any one of claims 1 to 8, wherein, The distance (L1) from the downstream end of the oxidizing medium injector (4) to the downstream end of the housing (2) of the oxy-fuel burner is equal to the outer diameter (d) of the oxidizing medium injector (4), while the distance (L2) from the downstream end of the ignition and flame control electrode (6) to the downstream end of the housing (2) of the oxy-fuel burner is equal to 0.5d.

16. The oxygen-fuel burner according to claim 9, wherein, The distance (L1) from the downstream end of the oxidizing medium injector (4) to the downstream end of the housing (2) of the oxy-fuel burner is equal to the outer diameter (d) of the oxidizing medium injector (4), while the distance (L2) from the downstream end of the ignition and flame control electrode (6) to the downstream end of the housing (2) of the oxy-fuel burner is equal to 0.5d.

17. The oxygen-fuel burner according to claim 10, wherein, The distance (L1) from the downstream end of the oxidizing medium injector (4) to the downstream end of the housing (2) of the oxy-fuel burner is equal to the outer diameter (d) of the oxidizing medium injector (4), while the distance (L2) from the downstream end of the ignition and flame control electrode (6) to the downstream end of the housing (2) of the oxy-fuel burner is equal to 0.5d.

18. The oxygen-fuel burner according to claim 12, wherein, The distance (L1) from the downstream end of the oxidizing medium injector (4) to the downstream end of the housing (2) of the oxy-fuel burner is equal to the outer diameter (d) of the oxidizing medium injector (4), while the distance (L2) from the downstream end of the ignition and flame control electrode (6) to the downstream end of the housing (2) of the oxy-fuel burner is equal to 0.5d.

19. The oxy-fuel burner according to any one of claims 1 to 8, wherein the oxy-fuel burner is adapted to be installed in a tuyer located in the wall of a smelting furnace, wherein, The distance from the downstream end of the housing (2) of the oxygen-fuel burner to the downstream end of the air outlet is between 2D and 3D, where D is the inner diameter of the air outlet.

20. The oxy-fuel burner according to claim 9, wherein the oxy-fuel burner is adapted to be installed in a tuyer located in the wall of a smelting furnace, wherein, The distance from the downstream end of the housing (2) of the oxygen-fuel burner to the downstream end of the air outlet is between 2D and 3D, where D is the inner diameter of the air outlet.

21. The oxy-fuel burner according to claim 10, wherein the oxy-fuel burner is adapted to be installed in a tuyer located in the wall of a smelting furnace, wherein, The distance from the downstream end of the housing (2) of the oxygen-fuel burner to the downstream end of the air outlet is between 2D and 3D, where D is the inner diameter of the air outlet.

22. The oxy-fuel burner of claim 12, wherein the oxy-fuel burner is adapted to be installed in a tuyer located in the wall of a smelting furnace, wherein, The distance from the downstream end of the housing (2) of the oxygen-fuel burner to the downstream end of the air outlet is between 2D and 3D, where D is the inner diameter of the air outlet.

23. The oxy-fuel burner according to claim 15, wherein the oxy-fuel burner is adapted to be installed in a tuyer located in the wall of a smelting furnace, wherein, The distance from the downstream end of the housing (2) of the oxygen-fuel burner to the downstream end of the air outlet is between 2D and 3D, where D is the inner diameter of the air outlet.

24. The oxy-fuel burner according to claim 19, wherein the oxy-fuel burner is adapted to be installed in an environment having a temperature of 250-650°C and a range of 700-1200 m. 3 / hr of blower air supply flow in the air outlet.

25. A system for automatically controlling the ignition and flame control of an oxygen-fuel burner according to any one of claims 1 to 24, wherein, The system includes: an ignition device; a combustion signal transmission device; a shut-off valve unit designed to connect to a gas-oxygen unit that regulates the flow rates of fuel, oxidant, oxidizing medium, and instrument air and supplies them to the oxygen-fuel burner; and a control unit designed to communicate with the gas-oxygen unit, the ignition device, the combustion signal transmission device, and the shut-off valve unit.

26. The system according to claim 25, wherein, The ignition device is a high-voltage transformer source.

27. A method for controlling the ignition and flame control of an oxy-fuel burner installed in a smelting furnace using the system according to claim 25 or 26, the method comprising the steps of: - Receive a signal confirming that the gas-oxygen unit has been turned on; - Determine the number of oxygen-fuel burners that need to be put into operation; - Open the shut-off valve in the shut-off valve unit to supply fuel and oxidant / oxidizing medium to the selected oxygen-fuel burner; - Initiate spark ignition of the selected oxygen-fuel burner; - Turn off spark ignition; - Monitor the flame in the oxygen-fuel burner during the monitoring process: Determine whether there is a flame in each oxygen-fuel burner. If a flame is found in all of the oxygen-fuel burners, continue the operation. However, if no flame is found in one or more of the oxygen-fuel burners, initiate spark ignition in the corresponding oxygen-fuel burner. - Maintain a record of the number of unsuccessful attempts to ignite the oxygen-fuel burner, wherein if the number exceeds a specified value, the supply of gas, oxidant and oxidizing medium to the corresponding oxygen-fuel burner (1) is stopped.

28. The method according to claim 27, wherein, The specified value for the number of unsuccessful attempts to ignite the oxygen-fuel burner (1) is five.

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