RU2249153C1 - Multi-jet burner for boiler - Google Patents

Abstract

FIELD: power engineering; burning fuel in various thermal plants and heat exchange apparatus.

SUBSTANCE: proposed multi-jet burner has combustion chamber which is closed on one side and is provided with outer and inner perforated tubes; it is made in form of double tube and is provided with distributing unit for smooth distribution of gas-and-air mixture; it is made in form of cone mounted in inner tube with its vertex directed towards gas-and-air mixture flow; ratio of diameter of outer tube to diameter of inner tube is no less than 1.2 and ratio of area of holes of inner perforated tube to area of holes of outer perforated tube is no less than 1.7. proposed burner excludes back-flash and enhances stable operation due to smooth distribution of gas-and-air flow, thus ensuring stable combustion over entire length of burner.

EFFECT: enhanced safety and reliability.

1 dwg

Description

The invention relates to the field of energy, concerns the design features of burners for burning gaseous fuels and can be used in various heat engineering devices, including heat exchangers, designed to heat products.

From (1), a multi-torch burner is known that contains a mixing chamber, closed on one side and designed to prepare a gas-air mixture, as well as external and internal perforated pipes. This multi-torch burner is a cylindrical device type “pipe in pipe”, taken as a prototype.

The disadvantages of this burner are the instability of its operation, due to the possibility of flame penetration through the holes of the perforated pipes inside the nozzle and into the mixer, as well as the uneven distribution of the gas-air mixture along the length of the tubular nozzle and, as a consequence, the uneven burning of flares at the very beginning and at the end of the tubular nozzle.

From (2), a multi-torch burner is known that contains a device for uniform distribution of the air-gas mixture, made in the form of a cone installed in the inner perforated tube of the gas burner with its apex facing the flow of the gas-air mixture entering it.

This multi-torch burner provides, as in the present invention, the formation of multiple torches uniformly distributed over the surface of the inner perforated tube of the burner, which leads to an increase in the heating area of the gas burner. In addition, the perforation of the pipe, in the inner cavity of which a device for uniform distribution of the gas-air mixture is installed, is proposed to be performed with a flow cross section less than the critical one, which ensures, as in the present invention, the burner is protected from leakage of flame into its gas distribution chamber. However, this burner does not have sufficient reliability and safety.

However, none of the multi-torch burners mentioned above can be characterized by high reliability and safety simultaneously with the high stability of its operation and the economical consumption of the gas-air mixture.

The technical result to which this invention is directed is to increase the safety and reliability of a multi-torch burner by preventing flame leakage, as well as to increase the stability of the burner by ensuring uniform distribution of the air-gas mixture flow and, therefore, its uniform burning along the entire length of the proposed multi-torch burners.

This technical result is achieved by the fact that a multi-torch burner containing a mixing chamber closed on one side, including external and internal perforated pipes and comprising a cylindrical “pipe in pipe” device, according to the invention, is equipped with a device for uniform distribution of the gas-air mixture, which is a cone mounted in the inner tube of the burner with its apex towards the flow of the gas-air mixture, the ratio of the diameter of the outer pipe to the diameter of the inner Pipes of at least 1.2, and the ratio of opening areas of the perforated inner tube to the outer area of the holes of the perforated tube is at least 1.7.

The invention is illustrated by the drawing, which shows the proposed multi-torch burner, which contains a mixing chamber, including external 1 and internal 2 pipes, and is a cylindrical device of the coaxial type “pipe in pipe”, closed on one side by bottom 4 and open on the other side, where prepared air-gas mixture is supplied. The ratio of the diameters of the mentioned outer 1 and inner 2 coaxial pipes is at least 1.2. In the cavity of the inner pipe 2, to ensure uniform distribution of the air-gas mixture along the entire length of the multi-torch burner, a cone 3 is mounted on the bottom 4 of the mixing chamber with the tip directed towards the flow of the prepared gas-air mixture. The walls of the outer 1 and inner 2 pipes are perforated with holes with a certain diameter, and the ratio of the hole area of the inner pipe 2 and the outer pipe 1 is at least 1.7.

Multi-torch burner operates as follows.

In the cavity of the inner pipe 2, a stream of prepared air-gas mixture is supplied under pressure, which, evenly distributed by means of the cone 3, is fed into the annulus through the perforated surface of the inner pipe 2. Additionally mixing in the annulus, the gas-air mixture flows through the perforation of the outer pipe 1 into the combustion zone and is ignited, forming multiple flares uniformly distributed over the cylindrical surface of the burner. If the ratio of the diameters of the outer 1 and inner 2 of the coaxial pipes is not less than 1.2, as well as the ratio of the hole area of the inner pipe 2 to the hole area of the outer pipe 1 of at least 1.7, the gas-air stream uniformly emanating from the perforations of the outer pipe 1 is provided mixture, eliminating the breakthrough of the flame, since the flow rate of the gas-air mixture at these ratios is always higher than the speed of propagation of the flame through the gas-air mixture.

Multi-torch burners of the proposed design are characterized by increased safety and reliability of their operation due to the prevention of flame leakage, and also provide fuel savings (prepared gas-air mixture) by increasing the stability of the multi-torch burner and expanding the limits of regulation of the heating area.

Sources of information:

1. DE 3831624 A1, 04/08/1989

2. RU 2186293 C1, 07/27/2002

Claims (1)

A multi-torch burner containing a mixing chamber, closed on one side, which includes the outer and inner perforated holes of the pipe and is a pipe-in-pipe cylindrical device, characterized in that it is equipped with a device for uniform distribution of the gas-air mixture, which is a cone, installed in the inner tube of the burner with the apex towards the flow of the gas-air mixture, while the ratio of the diameter of the outer pipe to the diameter of the inner pipe is at least 1.2, the area ratio of the holes perforated inner tube to the outer area of the holes of the perforated tube is at least 1.7.