Gas heater assembly for gas-heated process and system for gas-heated process

Abstract

The present disclosure relates to a gas heater assembly for a gas heating process, the assembly comprising: a burner body having a burner chamber for combusting injected fuel and an oxidizing gas and disposed within a cavity of the body in which the burner chamber is burning, a first transfer pipe for supplying injected fuel to the burner chamber, a second transfer pipe for supplying the oxidizing gas to the burner chamber, a burner housing having a housing wall configured to surround the burner body and form a first annular channel for gas in a space between an outside of the burner body and an inside of the housing wall of the burner housing, and at least one burner body support configured to support and center the burner body in the burner housing, the burner body having a flame port for a combustion flame configured to heat gas passing through the first annular channel. The present disclosure further relates to a system for a gas heating process.

Description

[Technical Field]

[0001] The present invention relates to a gas heater assembly for gas-heated processes and to a system for gas-heated processes, more particularly to a gas heater assembly for gas-heated processes and to a system for gas-heated processes as defined in the introductory parts of the independent claims. [Background technology]

[0002] Most commercial worldwide direct reduction technologies in the steel industry use natural gas to generate synthesis gas for reduction via stoichiometric, steam, or zero reformers, combining partial combustion systems with in-situ reforming. These technologies use direct reduction grade iron ore pellets or substitute pellets as feedstock to produce one of these products, which can be cold direct reduced iron, hot direct reduced iron, or hot briquetted iron.

[0003] The reducing gas used in the reduction process may be heated either in the reformer or in an external gas / fuel fired heater to a temperature of about 920-950°C, which may then be increased to a level of 980-1100°C at the point of injection into the reduction reactor using oxygen injection or a partial combustion system.

[0004] The thermal efficiency of externally fuel-fired combustion heaters may range nominally from 70-85%, with varying design, operating, reliability, and environmental conditions affecting the efficiency to maintain the designed / optimum level. In addition to the thermal combustion aspect, additional power is used to support the exhaust gas ventilators, combustion blowers, heating coils, heat recovery systems, and fireboxes required for the efficient functioning of the entire system.

[0005] There are many known applications for oxy-fuel burner systems. In the direct reduction process area, the primary commercial worldwide direct reduction technology, they are nominally referred to as oxygen-injected or partial-burned systems. In steelmaking electric arc furnaces, oxygen-injected systems are used to increase the thermal energy of melting by injecting oxygen in addition to coke, natural gas, and even hydrogen. These applications only partially meet or augment the thermal requirements of the system.

[0006] Current designs of conventional gas-fired heaters use air-fuel combustion to heat the reducing gas. Current conventional designs use an external fuel-fired burner as the heat source. Radiant heat from the burner is used to heat a heater coil / tube within the firebox, called the radiant section. The process gas or reducing gas passes through the heater coil and is heated by conduction from the tube walls.

[0007] Document EP 1017619 B1 discloses a burner for firing gases with an elongated burner tube. Summary of the Invention

[0008] Known heater systems include several components, such as a firebox, a heat recovery section, a burner, a fuel supply, a combustion fan, an induced draft fan, and a heater coil. The efficiency of these known heater systems may typically be between 70 and 85%. The design of known burners is often adapted to ensure that NOx and SOx exhaust gas emissions meet emission requirements. Known heat recovery systems also need to be properly designed to ensure that the outlet exhaust gas temperature is low but not below the dew point. The selection of the internal insulation lining affects the heat loss from the surface of the known heater box. The large surface area of the entire heater assembly results in significant heat loss.

[0009] Therefore, there exists a critical thermal efficiency limit beyond which design considerations for cost will prevent the system from being improved, resulting in limitations. Improved heater systems are therefore needed.

[0010] It is an object of the present invention to mitigate, alleviate or eliminate one or more of the above-mentioned drawbacks and disadvantages of the prior art, or at least to solve the above-mentioned problems.

[0011] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a gas heater assembly with increased thermal efficiency.

[0012] It is a further object of the present invention to provide a gas heater assembly that has a reduced environmental impact.

[0013] It is a further object of the present invention to provide a gas heater assembly that requires low maintenance and is reliable.

[0014] These objects are achieved by a gas heater assembly and a system for gas heating processes according to the appended claims.

[0015] According to a first aspect, there is provided a gas heater assembly for a gas heating process, the assembly comprising: a burner body having a burner chamber for combusting injected fuel and an oxidizing gas, the burner body being arranged within a cavity of the body in which the burner chamber is burning; a first transfer pipe for supplying injected fuel to the burner chamber; a second transfer pipe for supplying oxidizing gas to the burner chamber; a burner housing having a housing wall configured to surround the burner body and form a first annular channel for gas in a space between an outside of the burner body and an inside of the housing wall of the burner housing; and at least one burner body support configured to support and center the burner body in the burner housing, the burner body comprising a flame port for a combustion flame configured to heat gas passing through the first annular channel.

[0016] The present invention proposes an in-line internally fired process gas burner that achieves the highest thermal and combustion efficiency. Such a gas heater assembly heats the process gas internally without using a conventional combustion heater setup. Injected fuel and oxidizing gases reduce the environmental impact of combustion residues. The gas heater assembly provides an in-line burner, where the gas is heated by direct contact with the generated combustion flame. Therefore, such a gas heater assembly achieves improved thermal efficiency and reduces environmental impact. Furthermore, the gas heater assembly requires less maintenance and is reliable. The reduced number of parts in the gas heater assembly also reduces maintenance requirements. The burner body has a front end and a rear end. The front end of the burner body is configured to split and branch the gas to be heated and direct it into a first annular channel. The rear end of the burner body has a flame port for a combustion flame, which is configured to heat the gas passing through the first annular channel. The burner housing has a first open end and a second open end. The gas in the space between the outside of the burner body and the inside of the housing wall of the burner housing may be reduced in temperature. Accordingly, the burner housing comprises a housing wall that surrounds the burner body and is configured to form a first annular channel for the gas to be heated in the space between the outside of the burner body and the inside of the housing wall of the burner housing.

[0017] According to a second aspect, there is provided a system for a gas heating process, the system comprising: a furnace configured to receive heated gas; an inlet opening of the furnace configured to supply the heated gas to the furnace; and an outlet channel coupled to the furnace configured to remove gas from the furnace as spent or utilized gas and supply the gas to the inlet opening of the furnace via a recirculation circuit, the system comprising the gas heater assembly according to the first aspect.

[0018] This system, including the gas heater assembly described above, provides for the complete fulfillment of the heat requirements of the process, and improved thermal energy of the system is achieved. Furthermore, the low environmental impact of the gas heater assembly and the low maintenance requirements of the gas heater assembly result in a system with low environmental impact and low maintenance requirements. The advantages and features of the second aspect are largely similar to those described above in relation to the first aspect.

[0019] Additional objects, advantages, and novel features of the present invention will become apparent to those skilled in the art from the following details and through practice of the invention. While the invention is described below, it will be apparent that the invention is not limited to the details specifically described. Those skilled in the art, having access to the teachings herein, will recognize additional applications, modifications, and incorporations in other areas within the scope of the present invention. [Brief explanation of the drawings]

[0020] The above objects, as well as additional objects, features, and advantages of the present disclosure, will be more fully understood by reference to the illustrative and non-limiting detailed description of example embodiments of the present disclosure, taken in conjunction with the accompanying drawings.

[0021] [Figure 1] 1 is a schematic front view of a gas heater assembly according to one embodiment; [Figure 2] 2 shows a schematic cross-sectional view of the gas heater assembly taken along line AA in FIG. 1. [Figure 3] 1 illustrates a schematic diagram of a system for a gas heating process according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present disclosure will now be described with reference to the accompanying drawings. However, the present disclosure may be embodied in other forms and should not be construed as being limited to the disclosure set forth herein. The described disclosure is provided so as to fully convey the scope of the disclosure to those skilled in the art.

[0023] According to a first aspect, there is provided a gas heater assembly for a gas heating process, the assembly comprising: a burner body having a burner chamber for combusting injected fuel and an oxidizing gas, the burner body being arranged within a cavity of the body in which the burner chamber is burning; a first transfer pipe for supplying injected fuel to the burner chamber; a second transfer pipe for supplying oxidizing gas to the burner chamber; a burner housing having a housing wall configured to surround the burner body and form a first annular channel for gas in a space between an outside of the burner body and an inside of the housing wall of the burner housing; and at least one burner body support configured to support and center the burner body in the burner housing, the burner body comprising a flame port for a combustion flame configured to heat gas passing through the first annular channel.

[0024] The gas heater assembly may increase the temperature of the gas. The gas heater assembly may have an elongated extension. The gas heater assembly may direct the gas along the elongated extension of the assembly. The gas heating process may be a process for heating reducible grade iron ore pellets or substitute pellets. The gas may be heated to a level of 980-1100°C. Heat in the gas heater assembly is generated by a burner body. The burner body may be surrounded by the gas to be heated. The burner body may be shaped to allow the gas to be heated to flow through the burner body with as little resistance as possible. The gas in the space between the outside of the burner body and the inside of the housing wall of the burner housing may be cooled. Thus, the burner housing includes a housing wall configured to surround the burner body and form a first annular channel for the gas to be heated in the space between the outside of the burner body and the inside of the housing wall of the burner housing. The burner body may be shaped to control the direction of the gas flow. The burner body may be shaped to control the flow rate of the gas flow. The burner body may be shaped to control the flow pressure of the gas flow. The burner body may have a front end and a rear end. The burner body includes a cavity. The cavity may be configured as an open space at least partially surrounded by the wall of the burner body. Injected fuel is ignited in the burner chamber to generate heat. The burner chamber may be a combustion chamber. The burner chamber is formed of a material that can withstand high temperatures. The cavity of the burner body may be a burner chamber. The burner chamber may be a separate unit disposed within the cavity. The injected fuel may be a gaseous fuel. The injected fuel may be injected into the burner chamber through a nozzle. The nozzle configured to inject the injected fuel may be disposed directly in the burner chamber. An oxidizing gas may be injected into the burner chamber. The oxidizing gas is configured to combust with the injected fuel. The oxidizing gas may be injected into the burner chamber through a nozzle. The nozzle configured to inject the oxidizing gas may be disposed directly in the burner chamber. The first transfer pipe is configured to supply the injected fuel to the burner chamber.The first delivery pipe may be connected to a nozzle configured to inject injected fuel into the burner chamber. The injected fuel may be supplied from the first delivery pipe by pressure from a pressure vessel or a pump. The second delivery pipe is configured to supply oxidizing gas to the burner chamber. The second delivery pipe may be connected to a nozzle configured to inject oxidizing gas into the burner chamber. The injected fuel may be supplied from the second delivery pipe by pressure from a pressure vessel or a pump. The injected fuel and oxidizing gas may be supplied from the same delivery pipe and injected into the burner chamber through the same injection nozzle. The injected fuel and oxidizing gas may be mixed before igniting and burning in the burning chamber. The burner housing may be configured as a cylinder surrounding the burner body. The housing wall of the burner housing may be configured as a circle in cross section in a plane having a centerline as a normal to the plane. The housing wall may have a wall thickness that varies along the length of the burner housing. The burner housing may be open at both ends of the housing wall. A space is formed between the outside of the burner body and the inside of the housing wall of the burner housing. This space is the first annular channel. The first annular channel extends from the first end to the second end of the burner body. The first annular channel may be funnel-shaped. The inner diameter of the housing wall and the outer diameter of the burner body determine the width of the first annular channel. Gas is configured to flow through the first annular channel. The burner body may be immersed in the gas. The gas may be a process gas for heating materials in the steel industry, such as iron ore pellets. The burner housing may have a first open end and a second open end. Thus, the burner housing may have open ends on both housing walls. There may be at least one burner body support that fixes the position of the burner body relative to the burner housing. There may be several burner body supports spaced at equal distances from each other. The burner body support may center the burner body relative to the burner housing, so the width of the first annular channel may be uniform. The front end of the burner body is configured to divide and channel the gas to be heated into the first annular channel. The flame port may be located at the rear end of the burner body. The flame port may be circular in configuration.The combustion injected fuel and oxidizing gas create a positive pressure in the burner chamber. The positive pressure in the combustion chamber causes the combustion injected fuel and oxidizing gas to exit the combustion chamber through the flame port as a combustion flame. The gases flowing through the first annular channel pass through the combustion flame. As the gases pass through the combustion flame, they are heated by the combustion flame.

[0025] The first annular channel for gas has a first diverging section, where the gas to be heated enters the second converging section, increasing the velocity of the gas to be heated. The second converging section discharges at a third high-velocity section, where the temperature and velocity of the gas to be heated are increased by the combustion flame. In the first diverging section, the gas is evenly distributed within the first annular channel and around the burner body. The gas passes through the combustion flame and is at a lower temperature than when heated by the combustion flame. In the first diverging section, the diameter of the burner body may increase downstream of the first diverging section. In the first diverging section, the inner diameter of the housing wall of the burner housing may be constant or may increase or decrease slightly. In the second converging section, the shape of the second annular channel increases the flow velocity of the gas to be heated. In the third high-velocity section of the first annular channel, the gas passes through the combustion flame. At this stage, the temperature and velocity of the gas increase due to the speed of the flame. The first annular channel therefore comprises a first diverging section, a second converging section and a third high velocity section.

[0026] The burner body includes a domed nose cone configured to divide and diverge the gas to be heated and direct it to the second converging section. The domed nose cone may be disposed in the first diverging section. The front end of the burner body may include the domed nose cone. The diameter of the burner body may increase downstream of the first diverging section due to the domed nose cone. In the first diverging section, the inner diameter of the housing wall of the burner housing may be constant or may increase or decrease slightly. The domed nose cone may distribute the gas evenly within the first annular channel and around the burner body.

[0027] The front end of the burner body may include a dome-shaped nose cone. The dome-shaped nose cone may be located at the front end of the burner body. The dome-shaped nose cone located at the front end of the burner body may divide and branch the gas to be heated and direct it to the second converging section. The burner body located at the second converging section may have a frustoconical shape converging toward the burner body's flame port. The frustoconical shape of the burner body causes the second converging section of the first annular channel to form a funnel shape. The frustoconical shape of the burner body reduces the diameter of the burner body downstream of the second converging section of the first annular channel, and therefore, toward the burner body's flame port. The funnel-shaped portion of the second converging section of the first annular channel may be achieved by reducing the inner diameter of the inner wall of the burner housing. Reducing the area of the first annular channel downstream of the second converging section increases the flow velocity of the gas to be heated.

[0028] The velocity of the gas to be heated rising in the third high-velocity section may be configured to create a vacuum in the first branch section. The increased velocity of the heated gas in the third high-velocity section creates a gas flow through the first annular channel. The created gas flow facilitates delivery of the heated gas from the gas heater assembly. The vacuum may be a negative draft. Thus, the velocity of the gas to be heated rising in the third high-velocity section may be configured to create a vacuum or a negative draft in the first branch section. The velocity of the gas to be heated rising in the third high-velocity section may be configured to create a negative draft in the first branch section. The velocity of the gas to be heated rising in the third high-velocity section may be configured to create a gas flow through the first annular channel.

[0029] The first delivery pipe for supplying injected fuel to the burner chamber may be configured to supply hydrogen as the injected fuel, and the second delivery pipe for supplying oxidizing gas to the burner chamber may be configured to inject oxygen or air as the oxidizing gas to combust with the hydrogen. This assembly seeks the most efficient energy application method for the needs and aims of a power process that minimizes environmental impact. Using hydrogen as the injected fuel to the burner chamber meets these needs and aims. This assembly effectively prevents ambient air from participating in the combustion of the hydrogen and oxidizing gas, thereby reducing NOx production. Injecting air or a mixture of oxygen and air as the oxidizing gas to combust with the hydrogen reduces NOx production, which may reduce environmental impact. The reduced-temperature gas introduced into the first annular channel may be isolated and free of ambient air, thereby reducing NOx generation when heated by the combustion flame. Hydrogen from a makeup fuel source may be supplied as a first makeup gas to the reduced-temperature gas introduced into the first annular channel. The volume of ambient air as an oxidizing gas may be significantly less than the amount of oxidizing gas supplied to the combustion chamber, thereby reducing NOx production. The final product from the assembly may be a mixture of primarily HO exhaust gas and hot process gases, heated to the required temperature.

[0030] At least one burner body support may be configured to accommodate the first and second transfer pipes and lead them to the burner chamber of the burner body. The at least one burner body support fixes the position of the burner body relative to the burner housing. The first and second transfer pipes may be arranged in the same support. However, there may be multiple burner body supports. One burner body support may accommodate the first transfer pipe, and another burner body support may accommodate the second transfer pipe. The at least one burner body support may be aerodynamically shaped so that the support does not obstruct gas flow in the first annular channel. Thus, the first and second transfer pipes may penetrate the housing wall of the burner housing, the at least one burner body support, the wall of the burner body, and ultimately reach the burner channel or nozzle in the burner chamber.

[0031] The burner body may have a circular cross-section. The burner housing is configured to surround the burner body. The circular cross-section of the burner body, together with the burner housing surrounding the burner body, can evenly distribute the gas flow within the first annular channel. The evenly distributed gas flow can increase the efficiency of the gas heater assembly.

[0032] The first annular channel for the gas to be heated and the circular burner body may have a common centerline, and the coincidence of the centerlines of the first annular channel and the circular burner body may result in an even distribution of gas flow in the first annular channel.

[0033] The burner body includes a central burner element disposed within the cavity and including a burner chamber, and the outer wall of the burner body is configured to surround the central burner element and form a second annular channel between the outside of the central burner element and the inside of the outer wall of the burner body. The cavity of the burner body is configured to receive the burner chamber. A fixing means may be arranged to fix the burner chamber to the cavity of the burner body. This complex frustoconical arrangement of the central burner element has a section with a smaller radius in the direction of gas flow. Therefore, this arrangement may include an annular structure of multiple axially aligned cone inserts. The injected fuel and oxidizing gas are ignited within the central burner element, and combustion gases exit through the central burner element and the flame port of the burner opening. The second annular channel may insulate the burner body from radiant heat of the flame to maintain an acceptable constant burner body temperature.

[0034] The third transport pipe may be arranged to supply a second makeup gas to the second annular channel, and the second makeup gas is configured to flow out of the flame port of the burner body. The second makeup gas is configured to flow within the second annular channel. The second makeup gas flow can be adjusted based on the temperature of the gas to be heated in the first annular channel to control the flame temperature. The convergence of the burner body creates a high-velocity zone downstream of the burner body, which can result in a mixture of the flame and the second makeup gas reaching a uniform gas temperature. The second makeup gas may be hydrogen gas. The second makeup gas can control the flame temperature by enveloping or covering the combustion flame with fresh makeup gas. The second makeup gas can maintain an acceptable constant burner body temperature and shield the burner body from the radiant heat of the flame.

[0035] The burner body includes at least one intermediate burner element disposed in the second annular channel. Such an arrangement may include an annular structure of a plurality of axially aligned cone inserts. Injected fuel and oxidizing gas are ignited within the central burner element, and combustion gases exit through the central burner element and the flame port of the burner opening. Additional intermediate burner elements may be provided to form additional annular channels. A transfer pipe may be disposed in and connected to the additional annular channel. The transfer pipe may be configured to further supply make-up gas configured to flow out of the flame port of the burner body. The at least one intermediate burner element may shield the burner body from radiant heat of the flame to maintain an acceptably constant burner body temperature.

[0036] According to a second aspect, there is provided a system for a gas heating process, the system comprising: a furnace configured to receive heated gas; an inlet opening of the furnace configured to supply the heated gas to the furnace; and an outlet channel coupled to the furnace configured to remove gas from the furnace as spent or utilized gas and supply the gas to the inlet opening of the furnace via a recirculation circuit, the system comprising the gas heater assembly according to the first aspect.

[0037] The gas heating process may be a process for heating reducible-grade iron ore pellets or substitute pellets. The gas may be heated to a level of 980-1100°C. Heat is generated by a gas heater assembly. The furnace may be configured to accommodate grade iron ore pellets or substitute pellets. The furnace may be a vertical reduction furnace in which the pellets are reduced to metallic iron, such as sponge iron or direct reduced iron (DRI). Heated gas is supplied to the furnace through an inlet opening by the gas heater assembly. The gas heater assembly may be directly connected to the inlet opening of the furnace or may be connected via an inlet pipe. The furnace has an outlet opening to which an outlet channel is connected. The heated gas supplied from the inlet opening of the furnace is removed from the furnace through the outlet channel as spent gas or used gas. The outlet channel and the inlet channel are connected to each other via a recirculation circuit. The gas heater assembly is connected to the recirculation circuit between the outlet opening and the inlet opening of the furnace to supply gas to the inlet opening of the furnace.

[0038] A process gas recycle compressor may be coupled to the recycle circuit upstream of the gas heater assembly. The recycle compressor is configured to generate a mass flow of gas in the recycle circuit from the outlet opening to the inlet opening of the furnace. The mass flow of gas generated by the gas heater assembly may reduce the power of the recycle compressor.

[0039] The injection fuel source may be coupled to the gas heater assembly. The injection fuel source may include hydrogen as the injection fuel. The injection fuel may be pressurized in the injection fuel source and supplied to the gas heater assembly by pressure. The injection fuel source may be a pressure vessel. The injection fuel source may be coupled to a first delivery pipe to supply the injection fuel to a burner chamber of the gas heater assembly.

[0040] An oxidizing gas source may be coupled to the gas heater assembly. The oxidizing gas source may comprise oxygen or air. The oxidizing gas may be pressurized in the oxidizing gas source and supplied to the gas heater assembly by pressure. The oxidizing gas source may be a pressure vessel. The oxidizing gas source may be coupled to a second delivery conduit to supply the oxidizing gas to a burner chamber of the gas heater assembly.

[0041] Hydrogen from the makeup fuel source may be supplied to the gas heater assembly as a second makeup gas and / or to the recirculation circuit as a first makeup gas. Hydrogen from the makeup fuel source may be supplied to the recirculation circuit upstream of the gas heater assembly as the first makeup gas. Thus, the reduced temperature gas directed to the first annular channel of the gas heater assembly may be mixed with hydrogen from the makeup fuel source. Adding hydrogen as makeup gas may reduce NOx production in the gas heating process.

[0042] The furnace may be a direct reduction reactor for reducing iron ore to iron, in which iron ore oxide pellets are heated in a shaft furnace at high temperatures in the presence of a reducing gas to reduce the pellets to metallic iron, also known as sponge iron or direct reduced iron (DRI).

[0043] Exemplary Embodiments The present disclosure will now be described with reference to the accompanying drawings, in which preferred exemplary embodiments of the present disclosure are shown. However, the present disclosure may be embodied in other forms and should not be construed as limited to the embodiments disclosed herein. The embodiments of the present disclosure are provided so that the scope of the disclosure will be fully conveyed to those skilled in the art.

[0044] FIG. 1 is a schematic front view of a gas heater assembly 1 according to an embodiment. FIG. 2 is a schematic cross-sectional view of the gas heater assembly taken along line AA in FIG. 1. The gas heater assembly 1 includes a burner body 4 having a burner chamber 6 for combusting injected fuel 8 and oxidizing gas 10. The burner chamber 6 is disposed within a cavity 2 of the body 4 in which the injected fuel 8 and oxidizing gas 10 are combusted. The burner body 4 has a front end 5 and a rear end 7. A first transfer tube 12 is configured to supply injected fuel 8 to the burner chamber 6. A second transfer tube 14 is configured to supply oxidizing gas 10 to the burner chamber 6. A burner housing 16 having a housing wall 25 surrounds the burner body 4 and is configured to form a first annular channel 18 for gas 20 in a space 22 between the outside of the burner body 4 and the inside of the housing wall 25 of the burner housing 16. The burner housing 16 has a first open end 27 and a second open end 29. The burner body support 26 is configured to support and center the burner body 4 in the burner housing 16. The rear end 7 of the burner body 4 includes a flame port 28 for a combustion flame 30 configured to heat the gases 20 passing through the first annular channel 18.

[0045] The first annular channel 18 for the gas 20 includes a first diverging section 32 that directs the reduced temperature gas 20 into a second converging section 34, increasing the velocity of the reduced temperature gas 20. The second converging section 34 discharges in a third high velocity section 36 where a combustion flame 30 increases the temperature and velocity of the gas 20.

[0046] The front end 5 of the burner body 4 includes a dome-shaped nose cone 38 disposed in the first diverging section 32, which is configured to divide and branch the cooled gas 20 and direct it to the second converging section 34. The portion of the burner body 4 disposed in the second converging section 34 has a truncated conical shape that converges in a direction toward the flame port 28 of the burner body 4. The velocity of the gas 20 rising in the third high-velocity section 36 is configured to create a vacuum or negative draft in the first diverging section 32.

[0047] The first transport pipe 12 for supplying the injected fuel 8 to the burner chamber 6 is configured to supply hydrogen as the injected fuel 8, and the second transport pipe 14 for supplying the oxidizing gas 10 to the burner chamber 6 is configured to inject oxygen or air as the oxidizing gas 10 to be burned together with the hydrogen.

[0048] At least one burner body support 26 is configured to receive and direct the first and second transfer pipes 12, 14 to the burner chamber 6 of the burner body 4. The burner body 4 may have a circular cross section. The first annular channel 18 for gas 20 and the circular burner body 4 have a common centerline 40.

[0049] The burner body 4 comprises a central burner element 39 disposed within the cavity 2. The central burner element is shown in dashed lines in Figure 1. The central burner element 39 comprises a burner chamber 6. The outer wall 24 of the burner body 4 is configured to surround the central burner element 39 and form a second annular channel 41 between the outside of the central burner element 39 and the inside of the outer wall 24 of the burner body 4.

[0050] The third conveying pipe 43 is arranged to supply a second make-up gas 47 to the second annular channel 41, and the second make-up gas 47 is configured to flow out of the flame port 28 of the burner body 4. The burner body 4 comprises at least one intermediate burner element 45 arranged in the second annular channel 41. The intermediate burner element 45 is shown by a dashed line in Figure 2.

[0051] 3 is a schematic diagram of a system for a gas heating process according to an embodiment. A second aspect of the present disclosure illustrates a system 42 for a gas heating process. The system 1 includes a furnace 44 configured to receive heated gas 20. An inlet opening 50 is disposed in the furnace 44 configured to supply the heated gas 20 to the furnace 44. An outlet channel 52 is coupled to the furnace 44 and configured to remove the gas 20 from the furnace 44 as spent or used gas and to supply the gas 20 to the inlet opening 50 of the furnace 44 via a recirculation circuit 54. The gas heater assembly 1 is disposed in the recirculation circuit 54.

[0052] A process gas recycle compressor 58 is connected to the recycle circuit 54 upstream of the gas heater assembly 1. An injection fuel source 60 is connected to the gas heater assembly 1. An oxidizing gas source 62 is connected to the gas heater assembly 1.

[0053] Hydrogen from a makeup fuel source 64 is supplied to the gas heater assembly 1 as second makeup gas 47 and / or to the recirculation circuit 54 as first makeup gas 66. Hydrogen from the makeup fuel source 64 may also be supplied as injected fuel 8 to the burner chamber 6, indicated by dashed lines and arrows 70. The furnace may be a direct reduction reactor 44 for reducing iron ore 46 to iron 48. A gas cooling scrubbing device 68 is disposed in the recirculation circuit 54, in the outlet channel 52.

[0054] The foregoing description of the embodiments has been provided for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the embodiments to the variations described. Many modifications and variations will be apparent to those skilled in the art. The embodiments have been chosen and described to best explain the principles and practical applications, thereby enabling those skilled in the art to understand the embodiments in their various embodiments, along with various modifications applicable to their intended use. The above-identified components and features may be combined between different embodiments identified within the framework of the embodiments.

Claims

1. A gas heater assembly (1) for a gas heating process, A burner body (4) is located within a cavity (2) of a main body (4) in which the burner chamber (6) is burning, and has a burner chamber (6) for burning an injection fuel (8) and an oxidizing gas (10). A first transport pipe (12) for supplying the injection fuel (8) to the burner chamber (6), A second transport pipe (14) for supplying the oxidizing gas (10) to the burner chamber (6), A burner housing (16) comprising a housing wall (25), the burner housing (16) being configured to surround the burner body (4) and to form a first annular channel (18) for gas (20) in the space (22) between the outside of the burner body (4) and the inside of the housing wall (25) of the burner housing (16), the first annular channel (18) for gas (20) having a first branching section (32) that guides the gas (20) to be heated to a second convergence section (34) to increase the velocity of the gas (20) to be heated, the second convergence section (34) being discharged to a third high-speed section (36) that increases the temperature and velocity of the gas (20) to be heated by the combustion flame (30), The burner housing (16) includes at least one burner body support portion (26) configured to support and center the burner body (4), The burner body (4) has a flame port (28) for a combustion flame (30) configured to heat the gas (20) passing through the first annular channel (18), The burner body (4) has a dome-shaped nose cone (38) positioned in the first branch section (32), The assembly (1) is configured such that the dome-shaped nose cone (38) divides and branches the gas (20) to be heated and guides it to the second convergence section (34).

2. The assembly (1) according to claim 1, wherein the front end (5) of the burner body (4) is provided with the dome-shaped nose cone (38).

3. The assembly (1) according to claim 1 or 2, wherein the burner body (4) located in the second convergence section (34) is frustoconical in shape and converges in the direction toward the flame port (28) of the burner body (4).

4. The assembly (1) according to claim 1 or 2, wherein the velocity of the gas (20) to be heated rising in the third high-speed section (36) is configured to create a vacuum in the first branched section (32).

5. The first transport pipe (12) for supplying the injection fuel (8) to the burner chamber (6) is configured to supply hydrogen as the injection fuel (8), The assembly (1) according to claim 1 or 2, wherein the second transport pipe (14) for supplying the oxidizing gas (10) to the burner chamber (6) is configured to inject oxygen or air as the oxidizing gas (10) and burn it together with hydrogen.

6. The assembly (1) according to claim 1 or 2, wherein the at least one burner body support portion (26) is configured to house the first and second transport pipes (12, 14) and guide them to the burner chamber (6) of the burner body (4).

7. The assembly (1) according to claim 1 or 2, wherein the burner body (4) has a circular cross-section.

8. The assembly (1) according to claim 7, wherein the first annular channel (18) for the gas (20) to be heated and the circular burner body (4) have a common centerline (40).

9. The burner body (4) has a central burner element (39) that is arranged within the cavity (2) and includes the burner chamber (6), The assembly (1) according to claim 1 or 2, wherein the outer wall (24) of the burner body (4) surrounds the central burner element (39) and is configured to form a second annular channel (41) between the outside of the central burner element (39) and the inside of the outer wall (24) of the burner body (4).

10. The assembly (1) according to claim 9, wherein a third transport pipe (43) is arranged to supply a second makeup gas (47) to the second annular channel (41), and the second makeup gas (47) is configured to flow out of the flame port (28) of the burner body (4).

11. The assembly (1) according to claim 9, wherein the burner body (4) comprises at least one intermediate burner element (45) disposed in the second annular channel (41).

12. A system (42) for a gas heating process, A furnace (44) configured to receive heated gas (20), The furnace (44) has an inlet opening (50) configured to supply the heated gas (20) to the furnace (44), The furnace (44) is configured to remove the gas (20) as consumed gas or used gas from the furnace (44) and to supply the gas (20) to the inlet opening (50) of the furnace (44) via a recirculation circuit (54), and the outlet channel (52) connected to the furnace (44) is configured to do so. A system (42) comprising the gas heater assembly (1) according to claim 1.

13. The system (42) according to claim 12, wherein the process gas recirculation compressor (58) is connected to the recirculation circuit (54) upstream of the gas heater assembly (1).

14. The system (42) according to claim 12 or 13, wherein the injection fuel source (60) is connected to the gas heater assembly (1).

15. The system (42) according to claim 12 or 13, wherein the oxidizing gas source (62) is connected to the gas heater assembly (1).

16. The system (42) according to claim 12 or 13, wherein hydrogen from the makeup fuel source (64) is supplied to the gas heater assembly (1) as a second makeup gas (47) and / or to the recirculation circuit (54) as a first makeup gas (66).

17. The system (42) according to claim 12 or 13, wherein the furnace is a direct reduction reactor (44) for reducing iron ore (46) to iron (48).

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