Patent Grant
11226094
Embodiments of the present disclosure relate generally to burners and methods for use thereof.
Industrial furnaces can be used for a wide variety of processes, such as petroleum cracking, metal raw material melting, raw material sintering and heat treatment, or the like. These furnaces may have a burner as a core component for providing the heat to the furnaces using combustible fuels as energy sources. The burner may consist of a number of combustion units of the same type, each of which can generate combustion independent of other combustion units. The combustion conditions of combustion units are crucial for energy saving. The air supply nozzles of combustion units of the traditional industrial furnaces are generally arranged in parallel with the fuel nozzles. Therefore, the fuel (or gas fuel) and air are discharged in the same direction from the nozzles in front of the respective pipes, resulting in mixture of the fuel and air outside a combustion head of the burner. A main drawback of this structure is inadequate mixture of the air and fuel, leading to insufficient combustion of fuel. Further, thermal efficiency of the combustion fuel is relatively low and the exhaust fuel discharged from the furnace has high nitrogen content, which may not only cause a waste of energy but also pollute the environment.
A need exists for improved burners capable of adequate mixing, energy saving, and having reduced pollution to the environment. The burners herein may have multiple-stage mixing units arranged at a downstream portion of the burners. Each of the multiple-stage mixing units may include at least one fuel channel connected to at least one fuel pipe of the burner and at least one air channel connected to at least one air pipe of the burner. An outlet of the at least one fuel channel and an outlet of the at least one air channel may be angled at a certain angle relative to one another such that the fuel discharged from the outlet of the fuel channel can be sufficiently mixed with the air discharged from the outlet of the air channel. The air flow velocity of the air channel can be configured to be greater than the fuel flow velocity of the fuel channel such that a negative pressure can be generated at a mixing location of the air and fuel. The negative pressure generated in this way may draw more fuel discharged from the outlet of the fuel channel, thereby increasing the fuel-to-air ratio in the mixture while making the resulting mixture more uniform. The multiple-stage mixing at the outlets of the air and fuel channels, along with further mixing of those mixtures within a central mixing chamber, is advantageous in preventing the flashback and burnout that tends to occur in conventional burners due to excessive mixing.
According to one aspect of the present disclosure, a burner is provided. The burner can comprise: at least one air pipe; at least one fuel pipe; a plurality of groups of mixing units disposed at a downstream end of the burner, wherein each of the plurality of groups of mixing units is arranged coaxially and adjacent to one another, and each group of mixing units comprises at least one fuel channel connected to the at least one fuel pipe and at least one air channel connected to the at least one air pipe, wherein an outlet of the at least one fuel channel and an outlet of the at least one air channel are angled relative to one another such that fuel flowing out of the outlet of the at least one fuel channel is mixed with air flowing out of the outlet of the at least one air channel, thereby achieving multiple-stage mixing of the air and the fuel.
In some embodiments, the plurality of groups of mixing units can be disposed vertically along a central longitudinal axis of the burner.
In some embodiments, each group of mixing units can comprise a plurality of fuel channels, a plurality of air channels or a combination thereof.
In some embodiments, the plurality of groups of mixing units can comprise a first group of mixing units and a second group of mixing units.
In some embodiments, the first group of mixing units and the second group of mixing units can be arranged on a firing plate with three stages, and the three stages can comprise a first stage, a second stage and a third stage.
In some embodiments, the first group of mixing units can comprise a first plurality of air channels arranged on the first stage of the firing plate and a first plurality of fuel channels arranged on the second stage of the firing plate, and a central longitudinal axis of each of the first plurality of air channels can be angled relative to a central longitudinal axis of a corresponding one of the first plurality of fuel channels.
In some embodiments, the central longitudinal axis of each of the first plurality of air channels can be angled relative to the central longitudinal axis of the corresponding one of the first plurality of fuel channels ranging from approximately 45 degrees to 120 degrees.
In some embodiments, the central longitudinal axis of each of the first plurality of air channels can be angled relative to the central longitudinal axis of the corresponding one of the first plurality of fuel channels at approximately 90 degrees.
In some embodiments, the first plurality of air channels can be arranged circumferentially around the first stage of the firing plate.
In some embodiments, the first plurality of air channels can be evenly-spaced around a periphery of the first stage of the firing plate.
In some embodiments, the first plurality of air channel can be unevenly spaced around a periphery of the first stage of the firing plate.
In some embodiments, the first plurality of fuel channels can be arranged to be radially outwardly extended from a central longitudinal axis of the burner body.
In some embodiments, the number of the first plurality of fuel channels can be proportional or disproportional to the number of the first plurality of air channels.
In some embodiments, the number of the first plurality of fuel channels can be equal to the number of the second plurality of air channels.
In some embodiments, a cross section of an outlet of each of the first plurality of air channels can be circular and a radius of the outlet can be equal to a vertical distance of a bottom surface of the air channel to an outer edge of the second stage of the firing plate.
In some embodiments, the second group of mixing units can comprise a second plurality of air channels arranged on the second stage of the firing plate and a second plurality of fuel channels arranged on the third stage of the firing plate, and a central longitudinal axis of each of the second plurality of air channels can be angled relative to a central longitudinal axis of a corresponding one of the second plurality of fuel channels.
In some embodiments, the central longitudinal axis of each of the second plurality of air channels can be angled relative to the central longitudinal axis of the corresponding one of the second plurality of fuel channels at a degree ranging from approximately 45 degrees to 120 degrees.
In some embodiments, the central longitudinal axis of each of the second plurality of air channels can be angled relative to the central longitudinal axis of the corresponding one of the second plurality of fuel channels at approximately 90 degrees.
In some embodiments, each of the second plurality of air channels can be arranged to be a passage passing through the first and second stages of the firing plate to connect with the at least one air pipe.
In some embodiments, the second plurality of fuel channels can be arranged circumferentially around a periphery of the third stage of the firing plate.
In some embodiments, the number of the second plurality of fuel channels can be proportional or disproportional to the number of the second plurality of air channels.
In some embodiments, the number of the second plurality of fuel channels can be equal to the number of the second plurality of air channels.
In some embodiments, a cross section of an outlet of each of the second plurality of fuel channels can be circular and a radius of the outlet can be equal to a vertical distance of a bottom surface of each air channel on the second stage to an outer edge of the third stage of the firing plate.
In some embodiments, the plurality of groups of mixing units can comprise a first group of mixing units, a second group of mixing units and a third group of mixing units.
In some embodiments, the first group of mixing units, the second group of mixing units and the third group of mixing units can be arranged on a firing plate with three stages, and wherein the three stages can comprise a first stage, a second stage and third stage.
In some embodiments, the first group of mixing units can comprise a first plurality of air channels arranged on the first stage of the firing plate and a first plurality of fuel channels arranged on the second stage of the firing plate, and a central longitudinal axis of each of the first plurality of air channels can be angled relative to a central longitudinal axis of a corresponding one of the first plurality of fuel channels.
In some embodiments, the central longitudinal axis of each of the first plurality of air channels can be angled relative to the central longitudinal axis of the corresponding one of the first plurality of fuel channels at a degree ranging from approximately 45 degrees to 120 degrees.
In some embodiments, the central longitudinal axis of each of the first plurality of air channels can be angled relative to the central longitudinal axis of the corresponding one of the first plurality of fuel channels at approximately 90 degrees.
In some embodiments, the first plurality of air channels can be arranged circumferentially around the first stage of the firing plate.
In some embodiments, the first plurality of air channels can be evenly-spaced around a periphery of the first stage of the firing plate.
In some embodiments, the first plurality of air channel can be unevenly spaced around a periphery of the first stage of the firing plate.
In some embodiments, the first plurality of fuel channels can be arranged to be radially outwardly extended from a central longitudinal axis of the burner body.
In some embodiments, the number of the first plurality of fuel channels can be proportional or disproportional to the number of the first plurality of air channels.
In some embodiments, the number of the first plurality of fuel channels can be equal to the number of the second plurality of air channels.
In some embodiments, a cross section of an outlet of each of the first plurality of air channels can be circular and a radius of the outlet can be equal to a vertical distance of a bottom surface of the air channel to an outer edge of the second stage of the firing plate.
In some embodiments, the second group of mixing units can comprise a second plurality of air channels arranged on the second stage of the firing plate and a second plurality of fuel channels arranged on the third stage of the firing plate, and a central longitudinal axis of each of the second plurality of air channels can be angled relative to a central longitudinal axis of a corresponding one of the second plurality of fuel channels.
In some embodiments, the central longitudinal axis of each of the second plurality of air channels can be angled relative to the central longitudinal axis of the corresponding one of the second plurality of fuel channels at a degree ranging from approximately 45 degrees to 120 degrees.
In some embodiments, the central longitudinal axis of each of the second plurality of air channels can be angled relative to the central longitudinal axis of the corresponding one of the second plurality of fuel channels at approximately 90 degrees.
In some embodiments, each of the second plurality of air channels can be arranged to be a passage passing through the first and second stages of the firing plate to connect with the at least one air pipe.
In some embodiments, the second plurality of fuel channels can be arranged circumferentially around a periphery of the third stage of the firing plate.
In some embodiments, the number of the second plurality of fuel channels can be proportional or disproportional to the number of the second plurality of air channels.
In some embodiments, the number of the second plurality of fuel channels can be equal to the number of the second plurality of air channels.
In some embodiments, a cross section of an outlet of each of the second plurality of fuel channels is circular and a radius of the outlet can be equal to a vertical distance of a bottom surface of each air channel on the second stage to an outer edge of the third stage of the firing plate.
In some embodiments, the third group of mixing units can comprise a first plurality of air channels arranged on the third stage of the firing plate and a first plurality of fuel channels arranged on the second stage of the firing plate, and a central longitudinal axis of each of the first plurality of fuel channels can be angled relative to a central longitudinal axis of a corresponding one of the first plurality of gas channels.
In some embodiments, the first plurality of air channels of the third group of mixing units can be replaced by the at least one fuel pipe or a portion thereof at the center of the burner body.
In some embodiments, the second plurality of fuel channels of the third group of mixing units can be arranged annularly around the inner surface of the third stage.
In some embodiments, the central longitudinal axis of the each of second plurality of fuel channels can be angled relative to the central longitudinal axis of the burner body at an acute angle.
In some embodiments, the central longitudinal axis of the each of second plurality of fuel channels can be angled relative to the central longitudinal axis of the burner body at an angel selected from a range from 30 degrees to 90 degrees.
In some embodiments, a total sectional area of the air channels on the first stage of the firing plate can account for approximately 50%˜80% of a total sectional area of all the air channels on the three stages of the firing plate.
In some embodiments, the total sectional area of the air channels on the first stage of the firing plate can account for approximately 60% of the total sectional area of all the air channels on the three stages of the firing plate.
In some embodiments, the burner can further comprise a burner housing configured to encompass the plurality of groups of mixing units inside of the burner.
In some embodiments, the burner can further comprise a convergent nozzle arranged ahead of the plurality of groups of mixing units, and the convergent novel can be configured to converge a flame generated at a mixing zone and eject it out of the burner.
In some embodiments, a convergence angel of the convergent nozzle with respect to the central longitudinal axis of the burner body can range from 20 degrees to 70 degrees.
In some embodiments, refractory material can be filled between an outer surface of the convergent nozzle and an inner surface of the burner housing.
According to another aspect of the present disclosure, a method for using a burner is provided. The method can comprise: providing at least one air pipe and at least one fuel pipe of the burner; disposing a plurality of groups of mixing units at a downstream end of the burner, wherein each of the plurality of groups of mixing units can be arranged coaxially and adjacent to one another, and each group of mixing units can comprise at least one fuel channel connected to the at least one fuel pipe and at least one air channel connected to the at least one air pipe; arranging an outlet of the at least one fuel channel and an outlet of the at least one air channel such that the outlet of the at least one fuel channel and the outlet of the at least one air channel are angled relative to one another; supplying the air to the at least one air pipe; supplying the fuel to the at least one fuel pipe; mixing, by the plurality of groups of mixing units, the fuel flowing out of the outlet of the at least one fuel channel with the air flowing out of the outlet of the at least one air channel, thereby achieving multiple-stage mixing of the air and the fuel.
According to a further aspect of the present disclosure, a burner is provided. The burner can comprise: at least one air pipe; at least one fuel pipe; a plurality of groups of mixing units disposed at a downstream end of the burner, wherein each of the plurality of groups of mixing units can be arranged coaxially and adjacent to one another, and each group of mixing units can comprise at least one fuel channel connected to the at least one fuel pipe and at least one air channel connected to the at least one air pipe, wherein an outlet of the at least one fuel channel and an outlet of the at least one air channel can be angled at a certain degree relative to one another such that the fuel flowing out of the outlet of the at least one fuel channel is mixed with the air flowing out of the outlet of the at least one air channel, and wherein an air velocity of the air flowing out of the at least one air channel can be configured to be greater than a fuel velocity of the fuel flowing out of the at least one fuel channel such that at least one negative pressure is formed at a mixing location of the air and fuel.
According to an additional aspect of the present disclosure, a burner for generating a controlled flame is provided. The burner can comprise a burner housing arranged to encompass a burner body of the burner; a convergent nozzle arranged at an outlet of the burner; a central flame forming mechanism and a peripheral flame forming mechanism arranged along the downstream of the burner body adjacent to the convergence nozzle, wherein the central flame forming mechanism can comprise a plurality of central air channels and a plurality of central fuel channels, which can be angled with respect to an axial direction of the burner body, and wherein the peripheral flame forming mechanism can comprise a plurality of peripheral air channels and a plurality of peripheral fuel channels, which can be angled with the axial direction of the burner body, and whereby, a mixture of fuel and air can be ejected from the convergent nozzle through the central flame forming mechanism and peripheral flame forming mechanism, forming the controlled flame having an inner flame and a peripheral flame, wherein the inner flame is surrounded by a peripheral flame to form a desired shape of the controlled flame.
Other objects and features of the present invention will become apparent by a review of the specification, claims, and appended figures.
All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.
The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
The apparatus, systems and methods as described herein relate to burners that are capable of providing uniform mixtures of air and fuel, with low oxides of nitrogen (NOx) emissions and improvements in thermal efficiency. To this end, a firing plate with potential variations in some embodiments is designed and placed at a downstream of the burner in a direction of fuel flow. With aid of the firing plate, the air and fuel discharged or injected from an air channel and a fuel channel respectively, can be sufficiently mixed with one another to form a uniform mixture. Since the firing plate has a multi-stage shaped cross section and mixing of the air and fuel can occur at each stage, a multi-stage mixing of the air and fuel can be achieved without requiring additional mechanical mechanisms or components which could add to manufacturing costs and complexity. By properly controlling an air velocity and a fuel velocity, a negative pressure can be generated when the air velocity is greater than the fuel velocity, resulting in an increased fuel velocity. Therefore, more fuel will be drawn into the mixing, leading to more uniform mixing and higher fuel-to-air ratio. The technical effects and advantages as discussed herein are only for illustrative purposes and other effects or advantages may also be understood based on the embodiments of the present disclosure, as will be discussed in detail later.
It shall be understood that different aspects of the present disclosure can be appreciated individually, collectively, or in combination with each other. Various aspects of the disclosure described herein may be applied to any of the particular applications set forth below or for any other types of furnaces or burners.
The detailed descriptions of embodiments of the present disclosure will be set forth hereinafter with reference to the accompanying drawings.
As shown
Arranged on a front end of the burner body is a firing plate 19, which is configured to provide uniform and multi-stage mixing of the incoming air and fuel. The firing plate may comprise a plurality of stages, for example a first stage 20 of the firing plate, a second stage 21 of the firing plate, and a third stage 22 of the firing plate. In some embodiments, the plurality of stages may be formed as three frustums of a cone, for example shown in
Further shown in
One or more air channels can be arranged on the second stage of the firing plate, having respective outlets 25 as shown in
The number of fuel channels arranged on the third stage can be the same or different from the number of air channels arranged on the second stage 21 of the firing plate. In some embodiments, the number of fuel channels arranged on the third stage may or may not be proportional to the number of air channels arranged on the second stage. For example, the fuel and air channels can be in a one-to-one relationship or in a one-to-many relationship. In some cases, the air channels arranged on the second stage of the firing plate and the fuel channels arranged on the third stage of the firing plate collectively constitutes a mixing unit. Accordingly, the annularly arranged air and fuel channels can form a second group of mixing units for mixing the fuel and air as the fuel and air are being discharged from the respective channels.
In some embodiments, a central longitudinal axis of each of a plurality of air channels on the second stage of the firing plate has an angle relative to a central longitudinal axis of the corresponding one of a plurality of fuel channels on the third stage of the firing plate. The angle may range from approximately 45 degrees to 120 degrees. In some preferred embodiments, the angle may be at approximately 90 degrees, such that the fuel flowing out of the fuel channel and the air flowing out of the air channel is perpendicular to one another, which promotes mixing of the air and fuel. Further shown in
In some embodiments, a plurality of fuel channels 28 can be evenly spaced around the air pipe 13. In some cases, the fuel channels arranged on the third stage of the firing plate and the air pipe which also serves as an air channel at the third stage, collectively constitutes a third group of mixing units for mixing the fuel and air as the fuel and air are being discharged from the respective channels.
From the foregoing description with reference to
It can be understood that the shapes and arrangements of the firing plate as described herein are only for illustrative purposes and any suitable changes can be made without departing from the scope and spirit of the present disclosure. For example, although the firing plate and each stage thereof are shown as circular, the cross sections of the firing plate and each stage can be designed and manufactured having other shapes, such as oval, rectangular, triangular, trapezoid, pentagon, or any other regular or irregular polygons. Further, although the firing plate according to the embodiments of the present disclosure is depicted herein as a frustum of a cone with three stages (or three different frustums of a cone), other polyhedrons, such as a cuboid, cube, or the like, should also be envisaged by those skilled in the art based upon the teaching of the present disclosure.
In addition, although the air and fuel are introduced into the mixing chamber through a plurality of air and fuel channels (in the forms of apertures or openings) arranged in a series of axially adjacent stages, they can also be introduced into the mixing chamber via axially spaced stages. In some embodiments, the air and fuel channels are canted or canted relative to one another to develop a swirling of gas mixture, thereby enhancing fuel-air intermixture, ignition control and flame retention. According to the embodiments of the present disclosure, various parameters of the air channels and fuel channels can be determined depending on manufacturing requirements. The parameters may include but are not limited to a size (including diameter, radius, length, height, and width), a shape, a location, an orientation, a relative distance with respect to one or more axes or planes, for one or more components of the disclosed burner.
It is to be understood that the term “air” in the present disclosure may include any suitable oxidant that can cause or contribute to the combustion of other material, such as the ambient air or supplied oxygen, which allows for ignition and combustion. Further, the term “fuel” in the present disclosure may include any fuel gas, such as acetylene, natural gas, or propane, which, upon being mixed with the oxidant, produces a controlled flame used for petroleum cracking, metal raw material melting, raw material sintering and heat treatment.
It is further understood that
As illustrated in
The firing plate as shown is disposed on the downstream end of the air and fuel pipes. In some embodiments, the firing plate according to the embodiments of the present disclosure may be integrally formed with the air and fuel pipes or at least a section thereof. In some embodiments, the downstream end of the air and fuel pipes may be connected via threads with the firing plate. In some embodiments, the downstream end of the air and fuel pipes may be coupled (e.g., welded) to the firing plate. As discussed before with reference to
The air channels 23 herein may be confined by the inner surface of the burner housing and the outer surface of the first stage of the firing plate, thereby forming one or more hollow air passages, through which the air flowing from the air pipe will be discharged into the main mixing chamber 29. The cross section of the air channels 23 can be rectangular, thereby forming one or more slots or grooves around the periphery of the first stage of the firing plate. In some embodiments, the central longitudinal axis of the slots or grooves may be parallel to one of the central longitudinal axis of the burner body and the central longitudinal axis of the air pipe. In some embodiments, the central longitudinal axis of the slots has an angle relative to the central longitudinal axis of the air pipe, for example, ranging from about 30 degrees to about 85 degrees.
The air channels 26 may be hollow air passages passing through within the first and second stages of the firing plate along respective central axes parallel to the central longitudinal axis of the burner body. With this arrangement, the air within the annular air chamber 17 can directly flow into the main mixing chamber 29 by internally passing through the first and second stages of the firing plate. The fuel channels 24 are disposed within the second stage of the firing plate with outlets near the outlets of the air channel 23. In some embodiments, the fuel channels may be arranged radially extending from the inter surface of the fuel pipe 14. As described elsewhere herein, the central longitudinal axis of the fuel channels 24 may be angled relative to the central longitudinal axis of the air channels 23. In some embodiments, the central longitudinal axis of the fuel channels 24 may have an angle relative to the central longitudinal axis of the burner body ranging from approximately 45 degrees to 120 degrees. In some instances, the angle may be at approximately 90 degrees. With aid of this angular arrangement, the fuel and air can be sufficiently mixed to obtain premixed combustible fuel, which can be considered as a first-stage mixture according to the embodiments of the present disclosure.
Further shown on the third stage of the firing plate are annular fuel outlets 27 of the fuel pipe 15 and the annular air outlets 28 of the air pipe 13. The fuel pipe and air pipe serve as a fuel channel and an air channel, respectively, with annularly-arranged outlets. It can be seen from
The annular fuel outlets 28 of the air pipe 13 can be evenly spaced around the calathiform (i.e., a bowl-like shape) portion of the third stage and has an angle relative to the central longitudinal axis of the air pipe. In some embodiments, the angle between the central longitudinal axis of the fuel outlet 28 and the central longitudinal axis of the air pipe may be in a range from about 30 degrees to about 90 degrees. In this manner, the fuel flowing from the fuel pipe and air flowing from the air pipe can be mixed ahead of the outlets of the air pipe (i.e., at the main mixing zone), resulting in an adequate premix, which collectively constitutes a third-stage mixture according to the embodiments of the present disclosure.
In some embodiments, the total sectional area of the air channels on the first stage of the firing plate may account for approximately 50%˜80% of the total sectional area of all the air channels on the three stages of the firing plate. In some embodiments, the total sectional area of the air channels on the first stage of the firing plate may account for approximately 60% of the total sectional area of all the air channels on the three stages of the firing plate. The fuel pressure or air pressure in accordance with the embodiments of the present disclosure may be at 1 kg/cm2, 1.5 kg/cm2, 1.6 kg/cm2, 1.8 kg/cm2, 2.0 kg/cm2, 2.2 kg/cm2, 2.4 kg/cm2, 2.5 kg/cm2, 2.7 kg/cm2, 2.8 kg/cm2, 3.0 kg/cm2, 3.2 kg/cm2, 3.5 kg/cm2, 3.8 kg/cm2, 4.0 kg/cm2, 4.1 kg/cm2, 4.2 kg/cm2, 4.4 kg/cm2, 4.5 kg/cm2, 4.6 kg/cm2, 4.7 kg/cm2, 4.8 kg/cm2, 4.9 kg/cm2 or 5.0 kg/cm2. Alternatively or additionally, the fuel pressure or air pressure may be at 500 Pa, 600 Pa, 650 Pa, 700 Pa, 750 Pa, 800 Pa, 850 Pa, 900 Pa, 1000 Pa, 1100 Pa, 1200 Pa, 1300 Pa, 1500 Pa, 1600 Pa, 1700 Pa, 1800 Pa, 2000 Pa, 2200 Pa, 2300 Pa, 2500 Pa, 2700 Pa, 2800 Pa, 3000 Pa, 3100 Pa, 3200 Pa, 3500 Pa, 3600 Pa, 3800 Pa, 4000 Pa, 4200 Pa, 4300 Pa, 4400 Pa, or 4500 Pa. The fuel or air pressure herein may be more than or less than any value as exemplarily listed herein. Further, the fuel or air pressure can be selected from a scope ranging between any of two values as exemplarily listed herein.
A convergent nozzle 30 may be formed inside the burner housing and ahead of the firing plate, thereby defining the mixing chamber 29. The convergent nozzle can be made of fire-resistant and nonmetal materials. In some instances, refractory materials 31 can be filled between the outer surface of the convergent nozzle and the inner surface of the burner housing. Thereby, the burner housing can be protected from being damaged or deformed by burned air-fuel mixture, i.e., combustible fuel. In some embodiments, in order to obtain a desired flame shape, the convergent nozzle 30 can be arranged to converge at a predetermined angle relative to the central longitudinal axis of the burner body. For example, the convergent nozzle 30 may converge at an angle of about 20 degrees to about 70 degrees relative to the central longitudinal axis of the burner body. In some embodiments, the convergence angle herein may be about 45 degrees.
In operation, an operator can use an ignition apparatus to ignite the burner. The ignition apparatus may comprise a small burner capable of receiving fuel from the fuel source and air from the air source to form a combustible mixture, which can be subsequently ignited by an ignition device. In some embodiments, the ignition device may be a spark plug or similar device. The ignition of the burner according to the embodiments of the present disclosure can occur at any location where the air flowing from the outlet of the air channel and the fuel flowing from the outlet of the fuel channel are mixed with one another. Therefore, it would be easy for the operator to select and configure an ignition position of the burner. The ignition of the burner may take place in a few seconds after the multiple-stage mixing of the air and fuel. Depending on the multiple-stage arrangement together with outer and inner annular designs of the air channels and fuel channels, the burner according to the embodiments of the present disclosure can be used to generate a controlled flame for many different applications. Different portions of the flame burned after agitation of the combustible gas inside the main mixing chamber can have different temperatures. In some cases, a center temperature of the flame may be in a range from 1000° C.˜1800° C., 1200° C.˜2000° C., or 1500° C.˜2200° C. The center temperature of the flame can be in a range defined by any values as exemplarily listed herein. In some embodiments, the center temperature of the flame may be approximately at 1400° C. Further, an edge temperature of the flame may be in a range from 800° C.˜1100° C., 900° C.˜1200° C., or 950° C.˜1300° C. The edge temperature of the flame may be in a range defined by any values as listed herein. In some embodiments, the edge temperature of the flame may be at 850° C.
As illustrated in
In some embodiments, when the cross section of the fuel channels 24 is circular, the radius R1 of the fuel channel can be set taking into account a vertical distance H1 of the bottom surface of the air channel 23 to the outer edge of the second stage of the firing plate. In some instances, the radius R1 can be set as R1≤H1≤2R1. In some embodiments, the size of R1 can be set equal to the size of H1. Similarly, when the cross section of the fuel outlet 27 on the third stage of the firing plate is circular, the radius R2 thereof can be set taking into account a vertical distance H2 of the bottom surface of the air channel 26 to the outer edge of the second stage of the firing plate. In some instances, the radius R2 can be set as R2≤H2≤2R2. In some embodiments, the size of R2 can be set equal to the size of H2.
As shown in
Further shown at the second stage 21 of the firing plate are fuel outlets 35 of the fuel channels 24. It can be seen from the illustration that the fuel outlets are holes or openings circumferentially arranged around the periphery of the second stage 21, through which the fuel is discharged into the mixing zone for the first-stage mixture according to the embodiments of the present disclosure. As previously discussed, the central axes of the fuel outlets 35 have an angle with respect to the central axes of the air channels 23. In some embodiments, the central axes of the fuel outlets 35 can be perpendicular to the central axes of the air channels, thereby further facilitating mixing of the air and fuel at the mixing zones. Although the fuel outlets 35 as illustrated are evenly spaced around the periphery of the second stage of the firing plate, the fuel outlets 35 may be unevenly spaced around the periphery of the second stage of the firing plate. In some instances, one fuel outlet 35 may correspond to one air channel 23. Alternatively, one fuel outlet 35 may correspond to two or more air channel 23. In some instances, one air channel 23 may correspond to two or more fuel outlet 35.
Further illustrated in
From the foregoing description made with reference to
In some embodiments, the burner as discussed above may further comprise a peripheral flame forming mechanism comprising a plurality of peripheral air channels and a plurality of peripheral fuel channels. The peripheral flame forming mechanism may comprise the first and second stages of the firing plate, wherein the air channels on the first and second stages of the firing plate correspond to peripheral air channels, and the fuel channels on the first and second stages of the firing plate correspond to peripheral fuel channels. The central longitudinal axis of the air channel and the central longitudinal axis of the fuel channel can be angled with respect to each other, to promote premixing of the air and fuel.
The central flame forming mechanism and the peripheral flame forming mechanism described herein can be arranged along the downstream end of the burner body adjacent to the convergence nozzle. In this manner, a mixture of fuel and air can be ejected out of the convergent nozzle after passing through the central flame forming mechanism and peripheral flame forming mechanism, thereby forming the controlled flame having an inner flame and a peripheral flame, wherein the inner flame is surrounded by the peripheral flame to form a desired shape of the controlled flame. In practice, the flame can be stretched by a distance (e.g. one or two meters) from the outlet of the burner in an axial direction of the burner. In view of this, the target objects can be pre-located one or two meters away from the outlet of the burner, thereby achieving a good heating effect.
As shown
Arranged on a downstream end of fuel pipe 51 is a firing plate 55, which is capable of uniform and multi-stage mixing of the air and fuel. As shown, the firing plate may comprise three frustums of a cone corresponding to a first stage 56 of the firing plate, a second stage 57 of the firing plate, and a third stage 58 of the firing plate, which are coaxially adjacent to one another and have progressively decreasing diameters along the downstream of the burner. In some embodiments, one or more air channels 59 can be arranged on a periphery of an outer edge of the first stage 56. For example, the one or more air channels can be formed from slots or grooves, which can be evenly-spaced around the periphery of the first stage 56, thereby forming air channels between the outer surface of the first stage of the firing plate and the inner surface of the burner housing. In some embodiments, the central longitudinal axis of the air channel can be parallel to the central longitudinal axis of the burner body. In some embodiments, the central longitudinal axis of the air channel may be oblique relative to the central longitudinal axis of the burner body.
In some embodiments, a central longitudinal axis of each of a plurality of air channels on the first stage of the firing plate has an angle relative to a central longitudinal axis of the corresponding one of a plurality of fuel channels on the second stage of the firing plate. The angle may range from approximately 45 degrees to 120 degrees. In some instances, the angle may be approximately 90 degrees. In this way, the fuel flowing out of the fuel channel and the air flowing out of the air channel may be perpendicular to one another, thereby facilitating the sufficient mixing of the air and fuel.
The second stage of the firing plate can also be arranged one or more air channels 61 thereon, whose respective outlets are shown at 62. In some instances, a portion of the one or more air channels 61 can also be formed within the first stage of the firing plate. The air in the annular air chamber 53 can move along the air channels into the second stage and flow out of the outlets 63. Similar to the first and second stages of the firing plate, one or more fuel channels may be arranged on the third stage of the firing plate, having respective outlets shown at 63 in
In some embodiments, the number of fuel channels arranged on the third stage 58 can be the same or different from the number of air channels arranged on the second stage 57 of the firing plate. In some embodiments, the number of fuel channels arranged on the third stage may or may not be proportional to the number of air channels arranged on the second stage. For example, the fuel and air channels can be in a one-to-one relationship or in a one-to-many relationship. In some cases, the air channels arranged on the second stage 58 of the firing plate and the fuel channels arranged on the third stage 57 of the firing plate can collectively constitute a mixing unit. Therefore, the annularly arranged air and fuel channels can form a second group of mixing units for mixing the fuel and air as the fuel and air are discharged from the respective channels.
In some embodiments, a central longitudinal axis of each of a plurality of air channels on the second stage of the firing plate has an angle relative to a central longitudinal axis of the corresponding one of a plurality of fuel channels on the third stage of the firing plate, for example ranging from approximately 45 degrees to 120 degrees. In some instances, the angle may be approximately 90 degrees. In this way, the fuel flowing out of the fuel channel and the air flowing out of the air channel may be perpendicular to one another, thereby facilitating the sufficient mixing of the air and fuel.
From the foregoing description made above with reference to
From the illustration in
Further, it is to be understood that the shapes and arrangements of the firing plate as disclosed herein are only for illustrative purposes and any suitable changes and amendments can be made without departing from the scope and spirit of the present disclosure. For example, the cross sections of the firing plate and each stage can be designed and manufactured as having various shapes, such as oval, rectangular, triangular, trapezoid, pentagon, or any other regular or irregular polygons. Further, although the firing plate according to the embodiments of the present disclosure is depicted herein as a frustum of a cone with three stages (or three different frustums of a cone), other polyhedrons, such as a cuboid, cube, or the like, should also be envisaged by those skilled in the art based upon the teaching of the present disclosure.
In addition, although the air and fuel are introduced into the mixing chamber through a plurality of air and fuel channels (specifically in forms of apertures or openings) arranged in a series of axially adjacent stages, they can also be introduced into the mixing chamber via axially spaced stages. In some embodiments, the air and fuel channels are canted or canted relative to one another to develop a swirling of gas mixture, thereby enhancing fuel-air intermixture, ignition control and flame retention. In some cases, during the course of manufacture of the burner, various parameters of the air channels and fuel channels, including but not limited to a size (including diameter, radius, length, height, and width), a shape, a location, an orientation, a relative distance with respect to one or more axes or planes, can be taken into account. Therefore, a customized burner that is more suitable for practical use can be obtained.
Further, although not shown in
As illustrated in
In some embodiments, when the cross section of the fuel channels 60 is circular, the radius R3 of the fuel channel can be set taking into account a vertical distance 113 of the bottom surface of the air channel 59 to the outer edge of the second stage of the firing plate. In some instances, the radius R3 can be set as R3≤H3≤2R3. In some embodiments, the size of R3 can be selected as equal to the size of the 113. Similarly, when the cross section of the fuel outlet 63 on the third stage of the firing plate is circular, the radius R4 thereof can be set taking into account a vertical distance 114 of the bottom surface of the air channel 61 to the edge of the second stage of the firing plate. In some instances, the radius R4 can be set as R4≤H4≤2R4. In some embodiments, the size of R4 can be selected as equal to the size of 114.
As shown in
Further shown at the second stage 57 of the firing plate are fuel outlets 60 of the fuel channels. It can be seen from the illustration that the fuel outlets are holes or openings circumferentially arranged around the periphery of the second stage 57, through which the fuel is discharged into the mixing zone for the first-stage mixture according to the embodiments of the present disclosure. As previously discussed, the central axes of the fuel outlets 60 can have a predetermined angle with respect to the central axes of the air channels 59. In some embodiments, the central axes of the fuel outlets 60 can be perpendicular to the central axes of the air channels, thereby further facilitating mixing of the air and fuel at the mixing zones. Although the fuel outlets 60 as illustrated are evenly spaced around the periphery of the second stage of the firing plate, they may be unevenly spaced around the periphery of the second stage of the firing plate. In some instances, one fuel outlet 60 may correspond to one air channel 59. Alternatively, one fuel outlet 60 may correspond to two or more air channel 59. In some instances, one air channel 59 may correspond to two or more fuel outlet 60.
Further illustrated in
As illustrated in
At block S83, an outlet of the at least one fuel channel and an outlet of the at least one air channel are arranged, such that the outlet of the at least one fuel channel and the outlet of the at least one air channel are angled relative to one another. At block S84, during the operations of the burner, the air and fuel are supplied from an air source and a fuel source to the at least one air pipe and the at least one fuel pipe, respectively. When the air and fuel flow through the air pipe and fuel pipe, they enter into each group of the plurality of groups of mixing units stage-by-stage, through which the air and fuel are mixed, thereby achieving multiple-stage mixing of the air and the fuel.
As previously described, in some embodiments, the plurality of groups of mixing units is disposed vertically along a central longitudinal axis of the burner. In some instances, each group of mixing units may comprise a plurality of fuel channels, a plurality of air channels or a combination thereof. For example, the plurality of groups of mixing units may comprise a first group of mixing units and a second group of mixing units. In some instances, the plurality of groups of mixing units may further comprise a third group of mixing units. These groups of mixing units can be arranged on a firing plate with multiple stages. In some embodiments, the stages may comprise three stages, i.e., a first stage, a second stage, and a third stage.
In some instances, when the multiple stages are two stages, i.e., the first stage and the second stage, then the firing plate may have a configuration as previously shown in
Below is a table showing increased energy-saving rates obtained using the burner in accordance with the embodiments of the present disclosure, as compared to a conventional burner.
The conventional burner herein can be a burner that has a fuel channel with one or more discharge outlets at the end thereof and an air channel. In operation, the air and fuel can be mixed at the discharge outlets of the fuel channel. In other words, the conventional burner herein does not have multiple-stage mixing arrangements as discussed in accordance with the embodiments of the present disclosure.
As shown in the above table, the comparisons are made under given oxygen contents and three types of fuels are utilized for comparison, i.e., liquefied petroleum gas, natural gas and manufactured gas (e.g., coal gas). It can be seen that the burner in accordance with the embodiments of the present disclosure can significantly improve the energy-saving rate as compared to the conventional burner. For example, when the oxygen content in the exhaust gas is 1% in volume percent, the burner in accordance with the embodiments of the present disclosure can improve the energy-saving rate by 30% as compared to the conventional burner when the fuel is the liquefied petroleum gas. Similarly, the burner in accordance with the embodiments of the present disclosure can improve the energy-saving rate by 28% and 25% as compared to the conventional burner when the fuel is the natural gas and manufactured gas, respectively. From the above table, it can be seen that the burner in accordance with the embodiments of the present disclosure can achieve a higher energy-saving rate than the conventional burner, thereby lowering the fuel costs and decreasing the environmental pollution.
It is to be understood that the components of the burner can be arranged in any suitable configuration. For example, one or more of the components of the burner can be located on different locations based on the design requirements. Further, as used herein A and/or B encompasses one or more of A or B, and combinations thereof such as A and B. It will be understood that although the terms “first,” “second,” “third” etc. may be used herein to describe various elements, components, regions and/or sections, these elements, components, regions and/or sections should not be limited by these terms. These terms are merely used to distinguish one element, component, region or section from another element, component, region or section. Thus, a first element, component, stage, group, region or section discussed below could be termed a second element, component, region or section without departing from the teachings of the present invention.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including,” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components and/or groups thereof.
Furthermore, relative terms, such as “lower” or “bottom,” “inner” or “outer,” and “upper” or “top” may be used herein to describe one element's relationship to other elements as illustrated in the figures. It will be understood that relative terms are intended to encompass different orientations of the elements in addition to the orientation depicted in the figures. For example, if the element in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on the “upper” side of the other elements. The exemplary term “lower” can, therefore, encompass both an orientation of “lower” and “upper,” depending upon the particular orientation of the figure. Similarly, if the element in one of the figures were turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below.
While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. Numerous different combinations of embodiments described herein are possible, and such combinations are considered part of the present disclosure. In addition, all features discussed in connection with any one embodiment herein can be readily adapted for use in other embodiments herein. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.
This application is a continuation application of International Application No. PCT/CN2018/107015 filed on Sep. 21, 2018, which claims priority from PCT Application No. PCT/CN2017/103135 which was filed on Sep. 25, 2017, the content of which is hereby incorporated by reference in its entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5675971 | Angel et al. | Oct 1997 | A |
| 6565361 | Jones | May 2003 | B2 |
| 7244119 | Chung | Jul 2007 | B2 |
| 7303388 | Joshi | Dec 2007 | B2 |
| 10227922 | Whelan | Mar 2019 | B2 |
| 20090241942 | Schwank et al. | Oct 2009 | A1 |
| Number | Date | Country |
|---|---|---|
| 1675500 | Sep 2005 | CN |
| 106500096 | Mar 2017 | CN |
| 10005256 | Aug 2001 | DE |
| 0943863 | Sep 1999 | EP |
| 1445466 | Aug 2004 | EP |
| 1893915 | Mar 2008 | EP |
| 2442026 | Apr 2012 | EP |
| 1565247 | Apr 1980 | GB |
| WO-2010073156 | Jul 2010 | WO |
| WO-2019057166 | Mar 2019 | WO |
| Entry |
|---|
| European search report and opinion dated Mar. 24, 2021 for EP Application No. 18859487.3. |
| Number | Date | Country | |
|---|---|---|---|
| 20200224872 A1 | Jul 2020 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2018/107015 | Sep 2018 | US |
| Child | 16827568 | US | |
| Parent | PCT/CN2017/103135 | Sep 2017 | US |
| Child | PCT/CN2018/107015 | US |
