Gas heater assembly for gas heating process and system for gas heating process

Abstract

The present disclosure relates to a gas heater assembly (1) for a gas heating process, the assembly (1) comprising: a burner body (4) comprising a burner chamber (6) for combusting an injected fuel (8) and an oxidizing gas (10), the burner chamber (6) being arranged in a cavity (2) of the burner body (4); a first delivery pipe (12) for supplying injected fuel (8) to the burner chamber (6); a second delivery pipe (14) for supplying the oxidizing gas (10) to the burner chamber (6); comprising a housing wall (25), the burner housing being configured to surround the burner body (4) and to form a first annular passage (18) for the gas (20) in a space (22) between an exterior of the burner body (4) and an interior of the housing wall (25) of the burner housing (16); and at least one burner body support (26) configured to support the burner body (4) in the burner housing (16) and to center the burner body in the burner housing wherein the burner body (4) comprises a flame opening (28) for a combustion flame (30), the combustion flame is configured to heat the gas (20) passing through the first annular channel (18). The present disclosure also relates to a system (42) for a gas heating process.

Description

Technical Field

[0001] The present invention relates to a gas heater assembly for a gas heating process and a system for a gas heating process. More particularly, the present invention relates to a gas heater assembly for a gas heating process and a system for a gas heating process as defined in the preambles of the independent claims. Background Art

[0002] Most commercial global direct reduction technologies in the iron industry use natural gas via a stoichiometric reformer, steam reformer or zero reformer through a combination of a partial combustion system and an in-situ reforming unit to produce synthesis gas for reduction. These technologies can use direct reduced grade iron ore pellets or alternative pellets as a 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 can be heated in the reformer or in an external gas / fuel fired heater to a temperature of about 920 to 950 degrees C. This can be followed by an oxygen injection device or a partial combustion system to raise the temperature to a level of 980 to 1100 degrees C at the injection point of the reduction reactor.

[0004] Thermal efficiency of external fuel fired heaters can nominally be in the range of 70% to 85% and is dependent upon various design, operational, reliability and environmental conditions to maintain efficiency at design / optimum levels. In addition to the thermal combustion aspects, additional power is used to support the flue gas exhaust fan, combustion air blower, heating coils, heat recovery system, firebox, which is necessary for efficient operation of the entire system.

[0005] There are many known applications using oxygen fuel burner systems. In the direct reduction process field of the main commercial global direct reduction technology, oxygen fuel burner systems are nominally called oxygen injection systems or partial combustion systems. In steelmaking arc furnaces, oxygen injection systems are used to increase the heat energy used for melting via oxygen injection with coke, natural gas and even hydrogen. These applications only partially meet or increase the heat demand 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 burner as the heat source. Radiant heat from the burner is used to heat the heater coils / heater tubes in the firebox known as the radiant section. The process or reducing gas passes through / within the heater coils and is heated by heat conduction through the tube walls.

[0007] Document EP 1 017 619 B1 discloses a burner for burning gas, which burner comprises an elongated burner tube. Summary of the invention

[0008] Known heater systems include multiple components such as a firebox, a heat recovery section, a burner, a fuel supply, a combustion air blower, 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 typically customized to ensure NO X and SO X The flue gas emissions meet the emission requirements. The known heat recovery system also needs to be properly designed to ensure that the outlet flue gas temperature is low but not below the dew point. The choice 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 will result in large heat losses.

[0009] Therefore, there is a critical thermal efficiency limit beyond which the system may not be improved by design with respect to cost, which may result in limitations.Therefore, there is a need for an improved heater system.

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

[0011] It is therefore an object of the present invention to provide a gas heater assembly having improved thermal efficiency.

[0012] Another object of the present invention is to provide a gas heater assembly that produces a low environmental impact.

[0013] Another object of the present invention is to provide a reliable gas heater assembly with low maintenance requirements.

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

[0015] According to a first aspect, a gas heater assembly for a gas heating process is provided, the assembly comprising: a burner body, the burner body comprising a burner chamber for burning injected fuel and oxidizing gas, the burner chamber being arranged in a cavity of the burner body; a first delivery pipe, the first delivery pipe being used to supply the injected fuel to the burner chamber; a second delivery pipe, the second delivery pipe being used to supply the oxidizing gas to the burner chamber; a burner housing, the burner housing comprising a housing wall, the burner housing being configured to surround the burner body and form a first annular channel for gas in a space between the outside of the burner body and the inside of the housing wall of the burner housing; and at least one burner body support, the at least one burner body support being configured to support the burner body in the burner housing and center the burner body in the burner housing, wherein the burner body comprises a flame opening for a combustion flame, the combustion flame being configured to heat the gas passing through the first annular channel.

[0016] The present invention proposes a process gas inline internal combustion burner, which achieves the highest heat / combustion efficiency. In this gas heater assembly, the process gas is heated internally without using a conventional combustion heater device. Depending on the injected fuel and oxidizing gas, the residual products of combustion produce low environmental impact. The gas heater assembly provides an inline burner in which the gas will be heated via direct contact with the generated combustion flame. Therefore, in this gas heater assembly, improved thermal efficiency is achieved and low environmental impact is produced. In addition, the gas heater assembly is reliable and has low maintenance requirements. The reduction in the number of components of the gas heater assembly also leads to low maintenance requirements. The burner body includes a front end and a rear end. The front end of the burner body is configured to shunt, diverge and guide the gas to be heated into a first annular channel. The rear end of the burner body includes a flame opening for a combustion flame, which is configured to heat the gas passing through the first annular channel. The burner housing includes 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 can have a reduced temperature. Therefore, the burner housing including the housing wall is configured to surround the burner body and 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, a system for a gas heating process is provided, 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; an outlet channel connected to the furnace, the outlet channel configured to remove gas as waste gas or utilized gas from the furnace and to supply gas to the inlet opening of the furnace via a recirculation loop, wherein the system comprises: a gas heater assembly according to the first aspect.

[0018] In the system including the above-described gas heater assembly, full satisfaction of the thermal requirements of the process is provided and improved thermal energy of the system is achieved. In addition, due to the low environmental impact generated by the gas heater assembly and the low maintenance requirements of the gas heater assembly, the system also provides low environmental impact and low maintenance requirements. The effects and features of the second aspect are largely similar to those described above in conjunction with the first aspect.

[0019] Other purposes, advantages and novel features of the present invention will be apparent to those skilled in the art through the following detailed description and through implementation of the present invention. Although the present invention is described below, it should be apparent that the present invention is not limited to the details specifically described. Those skilled in the art who have obtained the teachings herein will recognize additional applications, modifications and combinations in other fields within the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above objects and other objects, features and advantages of the present disclosure will be more fully understood by referring to the following illustrative and non-limiting detailed description of example embodiments of the present disclosure when considered in conjunction with the accompanying drawings.

[0021] Figure 1 A gas heater assembly according to an example is schematically illustrated in a front view,

[0022] Figure 2 Along the Figure 1 The cross-sectional view along line AA in FIG. 1 schematically illustrates the gas heater assembly, and

[0023] Figure 3 A system for a gas heating process according to an example is schematically illustrated. DETAILED DESCRIPTION

[0024] The present disclosure will now be described with reference to the accompanying drawings. However, the present disclosure may be implemented in other forms and should not be construed as being limited to the disclosure described herein. The described disclosure is provided to fully convey the scope of the present disclosure to those skilled in the art.

[0025] According to a first aspect, a gas heater assembly for a gas heating process is provided, the assembly comprising: a burner body, the burner body comprising a burner chamber for burning injected fuel and oxidizing gas, the burner chamber being arranged in a cavity of the burner body; a first delivery pipe, the first delivery pipe being used to supply the injected fuel to the burner chamber; a second delivery pipe, the second delivery pipe being used to supply the oxidizing gas to the burner chamber; a burner housing, the burner housing comprising a housing wall, the burner housing being configured to surround the burner body and form a first annular channel for gas in a space between the outside of the burner body and the inside of the housing wall of the burner housing; and at least one burner body support, the at least one burner body support being configured to support the burner body in the burner housing and center the burner body in the burner housing, wherein the burner body comprises a flame opening for a combustion flame, the combustion flame being configured to heat the gas passing through the first annular channel.

[0026] The gas heater assembly can increase the temperature of the gas. The gas heater assembly can have an elongated extension. The gas heater assembly can guide the gas along the elongated extension of the assembly. The gas heating process can be a process of heating the gas for reducing grade iron ore pellets or replacing pellets. The gas can be heated to a level of 980 degrees Celsius to 1100 degrees Celsius. The heat in the gas heater assembly is generated by a burner body. The burner body can be surrounded by the gas to be heated. The burner body can have a shape that allows the gas to be heated to flow through and through the burner body with as low 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 can have a reduced temperature. Therefore, the burner housing including the housing wall is 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 can have a shape that controls the direction of the gas flow. The burner body can have a shape that controls the flow rate of the gas flow. The burner body can have a shape that controls the flow pressure of the gas flow. The burner body can include a front end and a rear end. The burner body is provided with a cavity. The cavity may be configured as an open space at least partially surrounded by the wall of the burner body. In the burner chamber, the injection fuel is ignited and burned for generating heat. The burner chamber may be a combustion chamber. The burner chamber is made of a material resistant to high temperatures. The cavity of the burner body may be a burner chamber. The burner chamber may be a separate unit arranged in the cavity. The injection fuel may be a gaseous fuel. The injection fuel may be injected into the burner chamber through a nozzle. The nozzle configured to inject the injection fuel may be directly arranged in the burner chamber. The oxidizing gas may be injected into the burner chamber. The oxidizing gas is configured to burn together with the injection fuel. The oxidizing gas may be injected into the burner chamber through a nozzle. The nozzle configured to inject the oxidizing gas may be directly arranged in the burner chamber. The first delivery pipe is configured to supply the injection fuel into the burner chamber. The first delivery pipe may be connected to a nozzle configured to inject the injection fuel into the burner chamber. The injection fuel may be supplied by pressure from a pressure vessel or by a pump through the first delivery pipe. The second delivery pipe is configured to supply the oxidizing gas into the burner chamber. The second delivery pipe may be connected to a nozzle configured to inject the oxidizing gas into the burner chamber. The injection fuel may be supplied by pressure from a pressure vessel or by a pump through the second delivery pipe. The injection fuel and the oxidizing gas may be supplied through the same delivery pipe and injected into the burner chamber through the same injection nozzle. The injection fuel and the oxidizing gas may be mixed together before the injection fuel and the oxidizing gas are ignited and burned in the combustion chamber. The burner housing may be a cylindrical member configured to surround the burner body. The housing wall of the burner housing may have a circular configuration in a cross-sectional view in a plane having a center line 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. The space is a first annular channel. The first annular channel has an extension from a first end of the burner body to a second end of the burner body. The first annular channel may have a funnel shape. The inner diameter of the housing wall and the outer diameter of the burner body determine the width of the first annular channel. The gas is configured to flow in 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 iron industry, such as iron ore pellets. The burner housing may include a first open end and a second open end. Therefore, the burner housing may be open in both ends of the housing wall. 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 a plurality of burner body supports, which are dispersed at a uniform distance from each other. The burner body support may center the burner body relative to the burner housing, so that the width of the first annular channel may be uniform. The front end of the burner body is configured to shunt, diverge and guide the gas to be heated into the first annular channel. A flame opening may be arranged in the rear end of the burner body. The flame opening may have a circular configuration. The burned injected fuel and oxidizing gas create a positive pressure in the burner chamber. Due to the positive pressure in the combustion chamber, the burned injected fuel and oxidizing gas will leave the combustion chamber through the flame opening as a combustion flame. The gas flowing in the first annular channel will pass through the combustion flame. When passing through the combustion flame, the gas is heated by the combustion flame.

[0027] The first annular channel for gas comprises a first diverging section in which the gas to be heated is directed into a second converging section in which the velocity of the gas to be heated increases, and wherein the second converging section discharges into a third high velocity section in which the combustion flame increases the temperature and velocity of the gas to be heated. In the first diverging section, the gas is evenly distributed in the first annular channel and around the burner body. The gas has a reduced temperature relative to the temperature of the gas when it passes through the combustion flame and has been 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 diameter of the interior of the housing wall of the burner housing may be constant or may increase or decrease slightly. In the second converging section, the flow velocity of the gas to be heated increases due to the shape of the second annular channel. In the third high velocity section of the first annular channel, the gas will pass through the combustion flame. At this stage, the temperature and velocity of the gas increase due to the flame velocity. Thus, the first annular passage includes a first diverging section, a second converging section, and a third high velocity section.

[0028] The burner body includes a dome-shaped nose cone configured to shunt, diverge and direct the gas to be heated into the second converging section. The dome-shaped nose cone may be arranged in the first diverging section. The front end of the burner body may include the dome-shaped nose cone. The diameter of the burner body may increase downstream of the first diverging section due to the dome-shaped nose cone. In the first diverging section, the diameter of the interior of the housing wall of the burner housing may be constant or may increase or decrease slightly. The dome-shaped nose cone may evenly distribute the gas in the first annular channel and around the burner body.

[0029] The front end of the burner body may include a dome-shaped nose cone. The dome-shaped nose cone may be arranged in the front end of the burner body. The dome-shaped nose cone arranged in the front end of the burner body may shunt, diverge and guide the gas to be heated into the second converging section. The burner body arranged in the second converging section may have a conical truncated shape that converges in the direction of the flame opening of the burner body. The conical truncated shape of the burner body forms a funnel shape of the second converging section of the first annular channel. The conical truncated shape of the burner body reduces the diameter of the burner body in the downstream direction of the second converging section of the first annular channel, and therefore also in the direction of the flame opening of the burner body. The funnel-shaped portion of the first annular channel located in the second converging section can be achieved by reducing the inner diameter of the inner part of the housing wall of the burner housing. Since the area of ​​the first annular channel downstream of the second converging section is reduced, the flow velocity of the gas to be heated is increased.

[0030] The increased velocity of the gas to be heated in the third high velocity section can be configured to form a vacuum in the first diverging section. Due to the increased velocity of the heated gas in the third high velocity section, a gas flow through the first annular channel is generated. The generated gas flow helps to transport the heated gas from the gas heater assembly. The vacuum can be a negative ventilation airflow. Therefore, the increased velocity of the gas to be heated in the third high velocity section can be configured to form a vacuum or a negative ventilation airflow in the first diverging section. The increased velocity of the gas to be heated in the third high velocity section can be configured to form a negative ventilation airflow in the first diverging section. The increased velocity of the gas to be heated in the third high velocity section can be configured to form a gas flow through the first annular channel.

[0031] The first delivery pipe for supplying injection fuel to the burner chamber can be configured to supply hydrogen as the injection fuel, and the second delivery pipe for supplying oxidizing gas to the burner chamber is configured to inject oxygen or air as the oxidizing gas for combustion with the hydrogen. The assembly seeks the most efficient energy application method to meet process requirements and aims to create the lowest environmental impact. Using hydrogen as the injection fuel to the burner chamber meets these requirements and goals. The assembly effectively prevents ambient air from participating in the combustion of hydrogen and oxidizing gas, which can reduce NO X Injecting air or a mixture of oxygen and air as an oxidizing gas to burn with hydrogen can reduce NO X The formation of NOx can be reduced, which can reduce the impact on the environment. The gas with a reduced temperature guided in the first annular channel can be isolated from and not affected by the ambient air, and thus will reduce NOx when heated by the combustion flame. X Hydrogen from a supplementary fuel source can be supplied as a first supplementary gas to the gas having a reduced temperature guided in the first annular channel. The volume of ambient air as an oxidizing gas is significantly lower than the volume of oxidizing gas supplied to the combustion chamber, which can therefore reduce NO X The final product from the assembly may be a mixture of flue gas, mainly H2O, and hot process gas heated to the desired temperature.

[0032] At least one burner body support can be configured to accommodate the first and second delivery pipes and guide the first and second delivery pipes into the burner chamber of the burner body. At least one burner body support fixes the position of the burner body relative to the burner housing. The first and second delivery pipes can be arranged in the same support. However, there can be multiple burner body supports. One burner body support can accommodate the first delivery pipe and another burner body support can accommodate the second delivery pipe. At least one burner body support can have an aerodynamic shape to prevent the support from interfering with the gas flow in the first annular channel. The first and second delivery pipes can therefore extend through the housing wall of the burner housing, through at least one burner body support, through the wall of the burner body and finally into the burner channel or reach the nozzle in the burner chamber.

[0033] 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 and the burner housing surrounding the burner body together may evenly distribute the gas flow in the first annular channel. Evenly distributed gas flow may improve the efficiency of the gas heater assembly.

[0034] The first annular channel for the gas to be heated and the circular burner body may have a common centerline.Arranging the first annular channel and the circular burner body such that their respective centerlines coincide may distribute the gas flow evenly in the first annular channel.

[0035] The burner body includes a central burner element arranged in a cavity, and the central burner element includes a burner chamber, and wherein the outer wall of the burner body is configured to surround the central burner element and form a second annular channel between the exterior of the central burner element and the interior of the outer wall of the burner body. The cavity of the burner body is configured to receive the burner chamber. The fixing device can be arranged to fix the burner chamber in the cavity of the burner body. This complex conical truncated arrangement structure of the central burner element has a smaller radius cross-section in the direction of gas flow. Therefore, this arrangement structure can include an annular structure of multiple conical inserts aligned axially. The injected fuel and oxidizing gas are ignited in the central burner element, and the combustion gas leaves the flame opening of the central burner element and the burner opening. The second annular channel can protect the burner body from the influence of flame radiation heat so as to maintain an acceptable and consistent burner body temperature.

[0036] The third delivery pipe can be arranged to supply the second supplementary gas to the second annular channel, and the second supplementary gas is configured to flow out through the flame opening of the burner body. The second supplementary gas is configured to flow in the second annular channel. The second supplementary 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 forms a high-speed region downstream of the burner body, in which the flame and the second supplementary gas mixture can therefore reach a uniform gas temperature. The second supplementary gas can be hydrogen. The second supplementary gas can surround or cover the combustion flame with fresh supplementary gas to control the flame temperature. The second supplementary gas can maintain an acceptable consistent burner body temperature and protect the burner body from the influence of flame radiation heat.

[0037] The burner body includes at least one intermediate burner element arranged in a second annular channel. This arrangement structure may include an annular structure of multiple tapered inserts aligned axially. Injected fuel and oxidizing gas are ignited in the central burner element, and combustion gases leave the flame opening of the central burner element and the burner opening. Additional annular channels may be formed by additional intermediate burner elements. Delivery pipes may be arranged and connected to additionally formed annular channels. The delivery pipes may be configured to supply additional supplementary gas, which is configured to flow out through the flame opening of the burner body. At least one intermediate burner element may protect the burner body from the effects of flame radiation heat so as to maintain an acceptable and consistent burner body temperature.

[0038] According to a second aspect, a system for a gas heating process is provided, 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; an outlet channel connected to the furnace, the outlet channel configured to remove gas as waste gas or utilized gas from the furnace and to supply the gas to the inlet opening of the furnace via a recirculation loop, wherein the system comprises: a gas heater assembly according to the first aspect.

[0039] The gas heating process can be a process for heating gas for reducing grade iron ore pellets or replacing pellets. The gas can be heated to a level of 980 degrees Celsius to 1100 degrees Celsius. Heat is formed by a gas heater assembly. The furnace can be configured to accommodate grade iron ore pellets or replace pellets. The furnace can be a vertical reduction furnace, wherein the pellets are reduced to metallic iron, such as sponge iron or direct reduced iron (DRI). The heated gas is supplied to the furnace by the gas heater assembly through the inlet opening of the furnace. The gas heater assembly can be directly connected to the inlet opening of the furnace or connected to the inlet opening of the furnace via an inlet pipe. The furnace includes an outlet opening, and an outlet channel is connected to the outlet opening. The heated gas supplied by the inlet opening of the furnace is removed from the furnace as waste gas or has been removed from the furnace by the outlet channel using gas. The outlet channel and the inlet channel are connected to each other via a recirculation loop. The gas heater assembly is connected to the recirculation loop between the outlet opening and the inlet opening of the furnace for supplying gas to the inlet opening of the furnace.

[0040] A process gas recirculation compressor may be connected to the recirculation loop and located upstream of the gas heater assembly. The recirculation compressor is configured to form a mass flow of gas in the recirculation loop from the outlet opening to the inlet opening of the furnace. The power of the recirculation compressor may be reduced due to the mass flow of gas formed by the gas heater assembly.

[0041] The injection fuel source may be connected 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 connected to a first delivery pipe for supplying the injection fuel to the burner chamber of the gas heater assembly.

[0042] An oxidizing gas source may be connected to the gas heater assembly. The oxidizing gas source may include 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 connected to a second delivery pipe for supplying oxidizing gas to the burner chamber of the gas heater assembly.

[0043] Hydrogen from the supplemental fuel source may be supplied to the gas heater assembly as a second supplemental gas and / or to the recirculation loop as a first supplemental gas. Hydrogen from the supplemental fuel source may be supplied to the recirculation loop upstream of the gas heater assembly as a first supplemental gas. Thus, the gas having a reduced temperature directed in the first annular passage of the gas heater assembly may be mixed with the hydrogen from the supplemental fuel source. Adding hydrogen as a supplemental gas may reduce NO in the gas heating process. X formation.

[0044] The furnace may be a direct reduction reactor for reducing iron ore to iron. In a direct reduction reactor, iron ore oxide pellets are heated at high temperature in a shaft furnace in the presence of a reducing gas, whereby the pellets are reduced to metallic iron, also known as sponge iron or direct reduced iron (DRI).

[0045] Example Implementations

[0046] The present disclosure will now be described with reference to the accompanying drawings, in which preferred example embodiments of the present disclosure are shown. However, the present disclosure may be implemented in other forms and should not be construed as being limited to the embodiments disclosed herein. The disclosed embodiments are provided to fully convey the scope of the present disclosure to the skilled person.

[0047] Figure 1 A gas heater assembly 1 according to an example is schematically illustrated in a front view. Figure 2 Along the Figure 1 The cross-sectional view of the line AA in FIG. 1 schematically illustrates a gas heater assembly. The gas heater assembly 1 includes a burner body 4, which includes a burner chamber 6 for burning an injection fuel 8 and an oxidation gas 10, which is arranged in a cavity 2 of the burner body 4. The burner body 4 includes a front end 5 and a rear end 7. A first delivery pipe 12 is configured to supply the injection fuel 8 to the burner chamber 6. A second delivery pipe 14 is configured to supply the oxidation gas 10 to the burner chamber 6. A burner housing 16 including a housing wall 25 is configured to surround the burner body 4 and 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 includes a first open end 27 and a second open end 29. The burner body support 26 is configured to support the burner body 4 in the burner housing 16 and to center the burner body 4 in the burner housing 16. The rear end 7 of the burner body 4 comprises a flame opening 28 for a combustion flame 30 which is configured to heat the gas 20 passing through the first annular channel 18 .

[0048] The first annular passage 18 for the gas 20 includes a first diverging section 32 where the gas 20 having a reduced temperature is directed into a second converging section 34 where the velocity of the gas 20 having a reduced temperature is increased. The second converging section 34 discharges into a third high velocity section 36 where the combustion flame 30 causes the temperature and velocity of the gas 20 to increase.

[0049] The front end 5 of the burner body 4 includes a dome-shaped nose cone 38 arranged in the first diverging section 32, which is configured to divert, diverge and guide the gas 20 having a reduced temperature into the second converging section 34. The portion of the burner body 4 arranged in the second converging section 34 has a conical truncated shape that converges in a direction toward the flame opening 28 of the burner body 4. The increased velocity of the gas 20 in the third high-velocity section 36 is configured to form a vacuum or negative draft airflow in the first diverging section 32.

[0050] The first delivery pipe 12 for supplying injection fuel 8 to the burner chamber 6 is configured to supply hydrogen as the injection fuel 8, and the second delivery pipe 14 for supplying oxidation gas 10 to the burner chamber 6 is configured to inject oxygen or air as oxidation gas 10 for combustion with hydrogen.

[0051] At least one burner body support 26 is configured to receive the first and second delivery tubes 12, 14 and guide the first and second delivery tubes 12, 14 into the burner chamber 6 of the burner body 4. The burner body 4 has a circular cross section. The first annular channel 18 for gas 20 and the circular burner body 4 have a common centerline 40.

[0052] The burner body 4 comprises a central burner element 39 arranged in the cavity 2. 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.

[0053] The third delivery pipe 43 is arranged for supplying a second supplementary gas 47 to the second annular channel 41, the second supplementary gas 47 being configured to flow out through the flame opening 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 arranged at Figure 2 Shown by dotted lines.

[0054] Figure 3A system for a gas heating process according to an example is schematically illustrated. A second aspect of the present disclosure shows a system 42 for a gas heating process. The system 1 includes a furnace 44 configured to receive a heated gas 20. An inlet opening 50 is arranged in the furnace 44, and the inlet opening 50 is configured to supply the heated gas 20 to the furnace 44. An outlet channel 52 is connected to the furnace 44, and the outlet channel 52 is configured to remove the gas 20 as waste gas or utilized gas from the furnace 44 and to supply the gas 20 to the inlet opening 50 of the furnace 44 via a recirculation loop 54. The gas heater assembly 1 is arranged in the recirculation loop 54.

[0055] A process gas recirculation compressor 58 is connected to the recirculation loop 54 and is located 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.

[0056] Hydrogen from a supplementary fuel source 64 is supplied to the gas heater assembly 1 as a second supplementary gas 47 and / or to the recirculation loop 54 as a first supplementary gas 66. Hydrogen from the supplementary fuel source 64 may also be supplied to the burner chamber 6 as an injection fuel 8, as indicated by the dashed line and arrow 70. The furnace may be a direct reduction reactor 44 for reducing iron ore 46 to iron 48. A gas cooling and cleaning device 68 is arranged in the recirculation loop 54 at the outlet channel 52.

[0057] The foregoing description of the examples has been provided for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the examples to the variations described. Many modifications and variations will be apparent to those skilled in the art. The examples have been selected and described to best illustrate the principles and practical applications, and thereby enable those skilled in the art to understand the examples in light of the various exemplary aspects of the invention and the various modifications applicable to the intended use of the invention. The above-mentioned components and features may be combined between the different examples described within the framework of the examples.

Claims

1. A gas heater assembly (1) for a gas heating process, the assembly (1) comprising: A burner body (4), the burner body (4) comprising a burner chamber (6) for burning injected fuel (8) and oxidizing gas (10), the burner chamber (6) being arranged in a cavity (2) of the burner body (4); a first delivery pipe (12) for supplying the injection fuel (8) to the burner chamber (6); a second delivery 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 a space (22) between the exterior of the burner body (4) and the interior of the housing wall (25) of the burner housing (16); and at least one burner body support (26) configured to support and center the burner body (4) in the burner housing (16), wherein: The burner body (4) includes a flame opening (28) for a combustion flame (30) configured to heat the gas (20) passing through the first annular passage (18).

2. The assembly (1) according to claim 1, wherein The first annular channel (18) for the gas (20) comprises a first diverging section (32), in which the gas (20) to be heated is guided into a second converging section (34), in which the velocity of the gas (20) to be heated is increased, and wherein the second converging section (34) discharges into a third high-velocity section (36), in which the combustion flame (30) increases the temperature and velocity of the gas (20) to be heated.

3. The assembly (1) according to claim 2, wherein: The burner body (4) includes a dome-shaped nose cone (38) arranged in the first diverging section (32), the dome-shaped nose cone (38) being configured to split, diverge and guide the gas (20) to be heated into the second converging section (34).

4. Assembly (1) according to claim 3, wherein: The front end (5) of the burner body (4) comprises the dome-shaped nose cone (38).

5. Assembly (1) according to any one of claims 2 to 4, wherein: The burner body (4) arranged in the second converging section (34) has a conical truncated shape which converges in a direction towards the flame opening (28) of the burner body (4).

6. Assembly (1) according to any one of claims 2 to 5, wherein: The increased velocity of the gas (20) to be heated in the third high velocity section (36) is configured to form a vacuum in the first diverging section (32).

7. Assembly (1) according to any one of the preceding claims, wherein The first delivery pipe (12) for supplying the injection fuel (8) to the burner chamber (6) is configured to supply hydrogen as the injection fuel (8), and the second delivery 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) for combustion with the hydrogen.

8. Assembly (1) according to any one of the preceding claims, wherein The at least one burner body support (26) is configured to receive the first and second delivery tubes (12, 14) and guide the first and second delivery tubes (12, 14) into the burner chamber (6) of the burner body (4).

9. Assembly (1) according to any one of the preceding claims, wherein The burner body (4) has a circular cross section.

10. Assembly (1) according to claim 9, wherein The first annular channel (18) for the gas (20) to be heated and the circular burner body (4) have a common center line (40).

11. Assembly (1) according to any one of the preceding claims, wherein The burner body (4) comprises a central burner element (39) arranged in the cavity (2), and the central burner element (39) comprises the burner chamber (6), and wherein 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).

12. Assembly (1) according to claim 11, wherein A third delivery pipe (43) is arranged for supplying a second supplementary gas (47) to the second annular channel (41), the second supplementary gas (47) being configured to flow out through the flame opening (28) of the burner body (4).

13. Assembly (1) according to any one of claims 11 and 12, wherein: The burner body (4) comprises at least one intermediate burner element (45) arranged in the second annular channel (41).

14. A system (42) for a gas heating process, the system (1) comprising: a furnace (44) configured to receive the heated gas (20); an inlet opening (50) of the furnace (44), the inlet opening (50) being configured for supplying the heated gas (20) to the furnace (44); an outlet channel (52) connected to the furnace (44), the outlet channel (52) being configured for removing the gas (20) as waste gas or utilized gas from the furnace (44) and for supplying the gas (20) to the inlet opening (50) of the furnace (44) via a recirculation loop (54), wherein the system comprises: A gas heater assembly (1) as claimed in any preceding claim.

15. The system (42) of claim 14, wherein: A process gas recirculation compressor (58) is connected to the recirculation loop (54) and is located upstream of the gas heater assembly (1).

16. The system (42) according to any one of claims 14 and 15, wherein: A fuel injection source (60) is connected to the gas heater assembly (1).

17. The system (42) according to any one of claims 14 to 16, wherein: An oxidizing gas source (62) is connected to the gas heater assembly (1).

18. The system (42) according to any one of claims 14 to 17, wherein: Hydrogen from a supplemental fuel source (64) is supplied to the gas heater assembly (1) as a second supplemental gas (47) and / or to the recirculation loop (54) as a first supplemental gas (66).

19. The system (42) according to any one of claims 14 to 18, wherein: The furnace is a direct reduction reactor (44) for reducing iron ore (46) to iron (48).

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