RU2044221C1 - Burner - Google Patents

Abstract

FIELD: chemical industry. SUBSTANCE: burner has gas pipe mounted inside the air pipe, flame stabilizer, and fairing. The flame stabilizer is made up as a hollow semi-torus. The fairing is secured to the air pipe through the diffuser. The stabilizer is made up as a cap and secured to the outlet end of the gas pipe. The edge of the cap is brought into the space of the semi-torus. EFFECT: improved design. 7 cl, 4 dwg

Description

 The invention relates to burners for burning liquid and gaseous fuels and can be used in chemical, petrochemical and other industries.

A burner device is known that contains an external pipe for supplying air, inside of which a gas pipe is installed along the axis, having a flame stabilizer at the output end in the form of a poorly streamlined body, forming an annular gap with the inner surface of the air pipe, and gas-emitting holes to the stabilizer [1]
This design has insufficient capabilities to force the process and does not provide the desired breadth of the working range of the air / fuel ratio (usually not wider than 8.5 to 11.5). This is due to the fact that with increasing load proportionally to the latter, the speed in the annular gap increases, and also because the direction of movement of the fresh mixture at the entrance to the combustion zone, which coincides with the direction of flame outflow, contributes to the possibility of disruption.

 The closest in technical essence to the present invention is a burner device containing an air pipe, inside which a fuel supply pipe is coaxially mounted, the output end of which is placed in the same plane as the output end of the air supply pipe, a hollow stabilizer with a central hole mounted against the output ends pipes and coaxially with them on the water supply and water discharge pipes, mounted on the outer surface of the air supply pipe [2] In this design, due to the removal of the stabilizer pa outside the burner pipe and the associated possibility of expanding the feed flow rate flowing on the stabilizer mixture grows weaker than the load. This extends the limits of stabilization of the flame in the ratio of air / fuel from about 8.0 to 15.

 However, in practice often more reliable flame stabilization is often required, which this burner does not provide. In addition, the disadvantages of this design include the impossibility of its operation in an inert atmosphere (for example, nitrogen, steam), which is often technologically necessary.

 The purpose of the invention is the expansion of the possible range of reliable operation, which is expressed in achieving reliable stabilization of the flame at high loads and in a wider range of air / fuel ratios, as well as in the possibility of the burner device operating in an inert atmosphere.

 To achieve this goal, a burner device containing a gas pipe placed inside the air pipe and a flame stabilizer further comprises a hollow one and a half cowl attached to the air pipe with a diffuser, and the stabilizer is made in the form of a bowl with the edges wound into the cavity one and a half , and attached to the outlet end of the gas pipe. At the outlet end of the gas pipe, gas outlets may be provided. The stabilizer can also be attached to the outlet end of the gas pipe by means of a switchgear and at the same time have gas outlets in communication with the cavity of the gas pipe at the periphery of its bottom. On the switchgear coaxially with the holes in the stabilizer, there may be holes of a smaller diameter provided with threads and circuit threaded plugs.

 An additional gas pipe may be located between the gas and air pipes, the stabilizer is provided with a central hole in communication with an additional central pipe placed inside the gas pipe and forming an annular gas supply channel with it, the bottom of the stabilizer bowl is lined with refractory material, and the entire device is enclosed in a housing with it an annular passage for supplying secondary air.

 In Fig.1 to 3 given a burner device, a longitudinal section, various options; in Fig.4 node I in Fig.3.

 The burner device according to FIG. 1 contains a gas pipe 1, to the outlet end of which a stabilizer made in the form of a bowl is attached 2. The gas pipe 1 is placed inside the air pipe 3, on which a cowl 5 made in the form of a hollow one and a half is mounted with a diffuser 4. At the output end of the gas pipe 1, openings 6 are made for the exit of gas. The edges of the bowl of the stabilizer 2 are introduced into the cavity of a half of the fairing 5.

 The burner device according to FIG. 2 is characterized in that an additional central pipe 7 is placed inside the gas pipe 1, which communicates with the central hole 8 of the stabilizer 2. The bottom of the stabilizer bowl is lined with refractory material 9.

 The burner device according to FIG. 3 is characterized in that an additional gas pipe 10 is installed between the gas 1 and air 3 pipes. The stabilizer 2 is attached to the output end of the gas pipe 1 by means of a distributing device 11. At the periphery of the bottom of the stabilizer 2 there are made gas outlets 12 in communication with the cavity gas pipe. In addition, on the switchgear 11 coaxially to the holes 12 in the stabilizer 2, holes 13 of smaller diameter can be made, provided with threads and removable threaded plugs 14. The plugs 14 included in the assembly I can have different lengths, which makes it possible to open the holes 12 and 13 (plugs removed), only hole 12 is open (short plugs, holes 12 and 13 are closed). The burner device can be enclosed in a housing 15, forming with it an annular passage for supplying secondary air.

 The burner device operates as follows. Primary air enters the annular gap between the pipes 1 and 3 (FIGS. 1 and 2) or between the pipes 3 and 10. Further, an ignition system, a flame control system (not shown), and natural gas are supplied.

 In the case of the structure of FIG. 1, gas is supplied through a pipe 1, from where it exits through openings 6 and then, mixed with air and rounding the edge of the bowl of the stabilizer 2, enters the bowl, moving first in the direction opposite to the main movement. In the case of the presence of a central pipe 7, as in FIG. 2, gas is supplied between the pipes 7 and 1, then it exits through the openings 6, is mixed with air and then follows, as in the construction of FIG. 1.

 If there is an additional gas pipe 10, as in FIG. 3, gas can be supplied through an annular gap between the pipes 10 and 1, after which the gas is mixed with air and enters the combustion zone as described above.

 In all these cases, gas is preliminarily mixed with air, which makes it possible to have a greater load, however, it is possible only with so small values of the exit gap between the edge of the stabilizer bowl 2 and the fairing 5 or at such high air-gas outflow velocities from this gap that exclude the possibility flamethrow into this gap.

 The device according to figure 3 provides for the possibility of supplying gas to the combustion zone without prior mixing. Gas is supplied through the pipe 1 (or into the annular gap between the pipes 1 and 7), after which it enters the combustion zone through the holes 12 along the periphery of the stabilizer 2 and the corresponding holes in the lining 9.

 The design of FIG. 3 enables the gas to be supplied to the combustion zone in various ways, i.e. without preliminary mixing with such and combined, as well as the ability to adjust the degree of mixing of gas with air by changing the number of holes 13 in the distributor 11, overlapped with plugs 14. This type of mixing adjustment is carried out during preliminary bench tests. The plugs are screwed (unscrewed) into the holes 13 of the distributor through the holes 12 in the stabilizer 2. If, after the gas supply, the flame monitoring system detects ignition, then make the necessary adjustments to the gas and air flow rates. If necessary, the required amount of secondary air is supplied into the annular gap between the casing 15 and the burner device itself. In the absence of ignition, the start of the burner is resumed, changing the initial costs.

 The principle of operation of this burner device is as follows. The gas-air mixture (in the absence of pre-mixing air), directed by the internal cavity of one and a half of the fairing 5 through the annular gap between this cavity and the edges of the stabilizer bowl entering it, flows at a sufficiently high speed (for example, 50 or more m / s) in the bowl cavity in the direction opposite to the main course of flows. Further, the gas-air mixture, guided by the shape of the walls and the bottom of the stabilizer bowl, makes a turn in the direction of the main movement of the flows and, being ignited in the initial ignition act, already leaves the reactor bowl in the form of incandescent flue gases. High-speed flow flowing from the fairing 5 in the direction opposite to the movement of flue gases, captures part of the latter, which ensures ignition.

 Thus, in this case, as with the usual stabilization of the flame by a poorly streamlined body, the latter is ensured by the presence of a vortex, which, however, is organized differently and is located not behind the stabilizer, but inside it.

 If during normal stabilization the direction of the speed of the fresh mixture in the ignition zone coincides with the main direction of the speed of the hot flue gases and therefore a relatively small increase in the speed of the fresh mixture leads to flame detachment, then in the design under consideration the opposite direction of these speeds provides more reliable stabilization both during forcing and when approaching the concentration limits of combustion.

 In some cases, the technology requires the burner to operate in an atmosphere of an inert or even fire extinguishing medium (nitrogen, water vapor, carbon dioxide). A burner device with a conventional stabilizer, in which inert leakage is possible in the ignition (stabilization) zone, does not provide stabilization in such conditions. The invention, due to the fact that the ignition zone is immersed inside the stabilizer bowl, ensures stable operation in an inert atmosphere.

Claims (7)

 1. BURNER DEVICE containing a gas pipe placed in the air pipe and a flame stabilizer, characterized in that it further comprises a hollow one and a half cowl attached to the air pipe with a diffuser, and the stabilizer is made in the form of a bowl with the edges wound up in the cavity of one and a half, and attached to the output end of the gas pipe.  2. The device according to claim 1, characterized in that at the output end of the gas pipe made gas-emitting holes.  3. The device according to claim 1, characterized in that the stabilizer is attached to the output end of the gas pipe by means of a distribution device, and along the periphery of the bottom of the stabilizer there are gas-emitting holes in communication with the cavity of the gas pipe.  4. The device according to claim 3, characterized in that on the switchgear coaxially with the holes in the stabilizer holes are made of a smaller diameter, equipped with threads and removable threaded plugs.  5. The device according to claim 3, characterized in that between the gas and air pipes there is an additional gas pipe.  6. The device according to paragraphs. 1 to 5, characterized in that the stabilizer is provided with a Central hole in communication with an additional Central pipe placed in a gas pipe and forming with it an annular gas supply channel.  7. The device according to paragraphs. 1 6, characterized in that it is enclosed in a housing, forming with it an annular gap for supplying secondary air.

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