RU2355949C2 - Flare burner - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: invention relates to gas burning devices operated with the use of Coanda effect and can be used in gas industry to burn purge gases of the boreholes being repaired. A flare burner comprises a casing with a coaxially set pipe which is fitted with a splitter in the form of a Coanda body on the periphery of the section projecting out of the casing outline. The splitter is mounted with a gap in respect to the upper casing end face and a suction pipe is additionally fitted in the above pipe. The pipe section inside the casing is holed and the pipe section outside the casing is made as a de Laval nozzle. The de Laval nozzle is divided into at least two parts set one in the other and forming an annular profiled mixing chamber; the Coanda body cavity is connected to the environment by channels.

EFFECT: ensuring the maximally possible gas combustion completeness with reduced content of harmful impurities in the combustion products.

2 cl, 1 dwg

Description

The invention relates to gas burner devices operating using the Coanda effect, and can be used, for example, in the gas industry for burning purge gases of repaired wells.

One of the problems arising from the combustion of purge and associated gases, especially those containing condensate and hydrogen sulfide compounds, is to ensure the maximum possible completeness of gas combustion and to obtain combustion products with a minimum content of hydrogen sulfide compounds not exceeding the maximum permissible norms.

A flare device is known, consisting of the body of Coanda, inside of which there is a hole in the form of a Venturi nozzle equipped with a swirl in the narrow part of the diffuser, and at the outlet an ejector attachment consisting of three coaxially arranged nozzles and offset along the axis, forming annular slots between themselves.

One part of the gas to be burned is supplied to the combustion zone through the Venturi nozzle, and the other through the annular gap in the form of a gap through the body of Coanda. The swirl mounted inside the Venturi nozzle gives the flow a rotational movement, which leads to more intensive mixing of the flows in front of the combustion zone (RF patent No. 21113657 dated 06/14/96, IPC F23D 14/20).

The main disadvantage of this flare device is that when a condensate-containing gas is supplied, the condensate, despite the rotational movement of the flow, does not completely have time to separate from the gas and enters the combustion zone, which leads to a deterioration in the combustion conditions and an increased concentration of harmful substances in the combustion products.

Known flare burner containing a gas supply barrel, a cylindrical shell for supplying air, installed along the axis of the gas supply barrel, and a conical shell located around the cylindrical shell with the formation of a vortex chamber, in which a swirl is installed, which forms an end gap with the gas supply barrel, while the air intake the device is made in the form of a cross-shaped partition mounted on the end section of the barrel and equal in height to the specified end gap, moreover, on the windproof and cone A visor and a recess, respectively, are formed in the shells at the entry point of the electric igniter, forming a stable ignition zone (RF patent No. 2033575 of 09.15.89, IPC F23D 14/20).

The main disadvantage of this flare burner is that when a condensate-containing gas is supplied, the condensate, despite the rotational movement of the stream, does not completely have time to separate from the gas and enters the combustion zone, which leads to a deterioration in the combustion conditions and an increased concentration of harmful substances in the combustion products.

A burner is known that contains a housing with a coaxially mounted pipe, provided on the periphery of a portion outside the housing, with a Koanda body divider placed with a gap relative to the upper end of the housing, while a suction tube is additionally installed in the pipe, the lower end of which is brought into the housing, and in the pipe section located in the casing, broadening was made with holes along its generatrix, while the ratio of the gap to the output section of the pipe was 0.75-1.3 (USSR AS No. 643719 dated 01/06/07, MKI F23D 13/20).

The disadvantages of the known burner are incomplete combustion of gas and condensate, an increased content of harmful impurities in the combustion products.

Known and closest in technical essence to the proposed invention is a burner containing a housing with a coaxially mounted pipe, equipped on the periphery of the section outside the housing, a divider in the form of a Koanda body, placed with a gap relative to the upper end of the housing, while the pipe is additionally installed a suction tube, the lower end of which is brought into the body, and in the pipe portion placed in the housing, broadening is made with holes along its generatrix, while the ratio of the gap area to pl the width of the outlet section of the pipe is 0.75-1.3, the portion of the pipe outside the housing is made in the form of a Laval nozzle, and the upper end of the suction tube is placed at the entrance to the specified nozzle (AS USSR No. 937888 from 01.10.80 , additional to AS No. 643719, MKI F23D 13/20 - prototype).

The specified burner operates as follows.

The gas discharged from the well is supplied to the pipe and is divided into two streams. The first gas stream enters the Laval nozzle, and the second stream through the pipe openings enters the burner body. At the exit from the holes, the gas at the initial time moves in the direction of the lower part of the housing, and then changes the direction of movement to the opposite and moves to the lateral annular gap. When the direction of movement changes, the gas is separated from the liquid phase (condensate), which is collected in the lower part of the housing. The cleaned gas stream, leaving the lateral annular gap, due to the arising Coanda effect sticks to the surface of the divider and creates a low pressure zone around it, into which the surrounding air is drawn. The air is mixed with the incoming gas and the resulting air-gas mixture moves in the direction of the generatrix of the conical section of the divider to the outlet of the first gas stream.

The first gas stream, leaving the pipe from the Laval nozzle, draws in condensate from the housing using a suction tube. The condensate stream, due to the increased gas velocity in a narrow section of the Laval nozzle, is crushed into fine droplets, mixed with the first gas stream and the second gas-air stream. The resulting mixture of gas, air and condensate burns smokeless.

The main disadvantage of this burner is insufficient mix formation between the gas being burned and the air of the surrounding atmosphere, which leads to a decrease in the completeness of combustion of not fully purified gases and an increase in the content of harmful emissions, in particular hydrogen sulfide and its compounds, in the combustion products.

The technical task of the invention is to eliminate these drawbacks and create a burner, the design of which allows to ensure the highest possible completeness of combustion of gases with a reduced content of harmful impurities in the combustion products.

The task is achieved due to the fact that in the proposed flare burner containing a housing with a coaxially mounted pipe, equipped on the periphery of a section extending outside the housing, a Koanda body divider placed with a gap relative to the upper end of the housing, while the pipe is additionally installed the suction tube, holes are made in the pipe portion installed in the housing, and the pipe portion extended outside the housing is made in the form of a Laval nozzle according to the invention, the Laval nozzle is divided into at least two parts included in one another and forming a profiled annular mixing chamber, the Coanda body cavity is connected by means of channels to the environment.

In order to withdraw the input ends of the channels from the gas-air mixing zone and supply clean, without gas impurities, air to the combustion zone, the channel inlet parts protrude above the outer surface of the divider.

Comparative analysis with the prototype shows that in the inventive device, in contrast to the constructive implementation of the prototype, the Laval nozzle is divided into at least two parts that enter one another and form a mixing chamber with an annular gap for ejecting air from the cavity of the body of Coanda, connected at help channels with the environment.

This solution allows air to be fed into the nozzle in the form of a continuous hollow ring in contact with the stream of gas being burned both on the external and internal surfaces, which allows improving the conditions of mixture formation and decreasing the length of the non-decaying part of the jet.

Thus, the set of essential features of the claimed technical solution, due to the presence of new features, provides a technical result, which is expressed in improving the conditions of gas mixing and obtaining increased completeness of combustion of the gas-air mixture by improving the conditions of mixture formation.

These essential features in the aggregate characterizing the essence of the claimed technical solution are not currently known for burners and devices for burning fuel. The analogue, characterized by the identity of all the essential features of the claimed invention, was not found during the studies, which allows us to conclude that the claimed technical solution meets the criterion of "Novelty."

The essential features of the claimed invention cannot be represented as a combination identified from known solutions with the implementation in the form of distinctive features to achieve a technical result, from which it follows that the criterion of "Inventive step" is met.

Due to the fact that the described technical solution is intended for use within a real gas afterburning system, in particular in the conditions of the Astrakhan gas condensate field, it was manufactured by the applicant and tested to achieve the claimed technical result, the proposed invention meets the criterion of "Industrial applicability".

The invention is illustrated in the drawing, which shows an axial section of the proposed burner.

The main elements of the proposed torch burner are:

1 - housing;

2 - pipe;

3 - peripheral area;

4 - divider;

5 - annular gap;

6 - channels;

7 - the output part of the nozzle;

8 - input part of the nozzle;

9 - annular gap;

10 - flange;

11 - suction tube;

12 - annular cavity;

13 - holes.

The burner comprises a housing 1 with a pipe 2 coaxially mounted inside the housing and provided with a divider 4 in the form of a Koanda body along the periphery of a portion 3 outside the housing 1. The divider 4 is installed with an annular gap 5 relative to the upper end of the housing 1. In the body of Coanda channels 6 are made connecting its cavity with the surrounding atmosphere.

The upper section 3 of the pipe 2, outside the housing 1, is shaped in the form of a profiled nozzle, for example, a Laval nozzle, consisting of at least two parts - output 7 and input 8, which are included in each other and form an annular gap 9.

In the lower section of the pipe 2, a counter flange 10 is installed for docking with the gas duct.

A suction tube 11 is installed in the pipe 2, the lower end of which communicates with the annular cavity 12 formed by the pipe 2 and the casing 1, and the upper one is brought out into the nozzle, consisting of parts 7 and 8. In the pipe 2 section installed in the casing 1, holes 13 are made .

The proposed burner operates as follows.

The gas discharged from the well enters pipe 2 and is divided into two streams. The first gas stream through the inner cavity of the pipe 2 enters a profiled nozzle consisting of two parts - inlet 8 and outlet 7, and the second stream through the holes 13 in the pipe 2 - into the annular gap between the housing 1 and the pipe 2. When leaving the holes 13 gas with condensate at the initial time is distributed between the suction pipe 11 and the annular gap between the housing 1 and the pipe 2. Due to the difference in densities and speeds of movement, the condensate flows into the installation area of the lower end of the suction pipe 11, and the gas purified from the liquid enters annular gap 5 between the housing 1 and 4 divider.

The purified gas stream, leaving the lateral annular gap 5, due to the arising Coanda effect sticks to the surface of the divider 4 and creates a low pressure zone around it, into which the surrounding air is drawn. The air is mixed with the incoming gas and the resulting gas-air mixture after ignition moves in the direction of the generatrix of the conical section of the divider to the outlet of the first gas stream.

When gas is discharged with increased pressure in a profiled nozzle, consisting of two parts 7 and 8, a supersonic flow regime is realized and, starting from a certain section, the pressure in the nozzle decreases below the pressure of the external medium. In this case, taking into account the presence of channels 6 due to the pressure difference between the external environment and the profiled nozzle, consisting of two parts, the air is sucked into the cavity of the profiled nozzle through the annular gap 9, where the gas mixture is further mixed with air, i.e. at the exit from the outlet of the nozzle 7, a mixture of gas and air prepared for combustion is created, which provides improved conditions for igniting the central stream and its more complete combustion when interacting with the torch coming from the outside along the generatrix of the divider 4.

The mixture of gas and air, leaving the outlet of the nozzle 7, draws in a suction tube 11, due to the difference in speeds, condensate from the annular cavity 12 formed by the housing 1 and the pipe 2.

Due to the fact that the condensate is supplied to the outlet of the nozzle 7, its increased turbulence and speed at the exit of the nozzle are ensured, and the flow is initially more efficiently crushed into fine droplets by the mixture at the exit of the nozzle, and then mixed with the gas-air mixture at the exit of the nozzle 7 The resulting mixture of gas, air and condensate interacts with the torch and burns smokeless, providing a reduced content of harmful impurities in the combustion products during combustion.

For a more efficient organization of gas-air mixing in the outlet part of the burner, made in the form of a profiled Laval nozzle 6, the inlet parts of the channels 6 can be located in the area of the inlet part of the divider 4.

In order to withdraw the input ends of the channels 6 from the gas-air mixing zone and supply clean, without gas impurities, air to the combustion zone, the input parts of the channels 6 protrude above the outer surface of the divider.

Using the proposed technical solution will improve the conditions of mixture formation, increase the completeness of combustion of condensate gases and reduce the content of harmful impurities in the combustion products by improving the combustion conditions of the gas-air mixture.

Claims (2)

1. A torch burner comprising a housing with a coaxially mounted pipe, provided at the periphery of a section extending outside the housing, with a Koanda body divider placed with a gap relative to the upper end of the housing, while a suction tube is additionally installed in the pipe in a pipe section installed Holes are made in the casing, and the pipe section extended outside the casing is made in the form of a Laval nozzle, characterized in that the Laval nozzle is divided into at least two parts that enter one another and form a prof an isolated annular mixing chamber, the Coanda body cavity is connected by means of channels to the environment. 2. The torch burner according to claim 1, characterized in that the input parts of the channels connecting the cavity of the body of Coanda with the environment, protrude above the outer surface of the body of Coanda.