CN108821615B

CN108821615B - Injector for annular sleeve kiln

Info

Publication number: CN108821615B
Application number: CN201810770303.XA
Authority: CN
Inventors: 代顺福; 武层层; 虞帮俊; 庞焕军; 张林进
Original assignee: Jiangsu Zhongshengyuan Technology Co ltd
Current assignee: Jiangsu Zhongshengyuan Technology Co ltd
Priority date: 2018-07-13
Filing date: 2018-07-13
Publication date: 2023-06-27
Anticipated expiration: 2038-07-13
Also published as: CN108821615A

Abstract

The invention provides an injector for an annular sleeve kiln, which comprises an injection pipe, a horn-shaped inlet pipe, a mixing pipe and a diffusion pipe, and further comprises an outer sleeve gas burner connected to the outside of the injection pipe, wherein the outer sleeve gas burner is suitable for receiving gas from the outside and enabling the gas to burn in the mixed gas of driving air and circulating smoke. The invention adds the outer sleeve gas burner, so that the gas can be burnt in the mixed gas of the driving air and the circulating flue gas, thereby releasing heat to improve the temperature of the mixed gas after the circulating flue gas and the driving air are mixed, and the mixed gas is higher than the condensation temperature (800 ℃) of sodium and potassium steam, thereby avoiding the problem of blockage of the ejector, not only improving the service life of the ejector and the operation rate of the sleeve kiln, but also realizing the staged combustion of fuel, being beneficial to improving the temperature uniformity of a combustion chamber under the sleeve kiln and avoiding the formation of a local high-temperature zone, and further inhibiting the generation of thermal NOx.

Description

Injector for annular sleeve kiln

Technical field:

the invention relates to an injection device for an industrial kiln, in particular to an injector for an annular sleeve kiln.

The background technology is as follows:

the annular sleeve kiln is used as a world-accepted high-quality shaft kiln, has the advantages of convenience in maintenance, environmental protection, high operation rate, high activity of finished lime, capability of using various types of inferior fuel and the like, and has been widely applied. The ejector is used as key equipment of the sleeve kiln, and can drive air with high energy to jet inner sleeve flue gas to form flue gas circulation in the kiln, so that a parallel flow calcining zone is formed in the sleeve kiln, and the aim of producing high-activity lime is fulfilled.

Because of the difference of impurity components in limestone ores and the difference of fuel components in each area, the injector on the annular sleeve kiln in each area has a problem of blockage, and when the blockage is serious, the injector needs to be cleaned once a month. When the injector is cleaned, the circulating air valve of the injector to be cleaned needs to be independently closed, after the injection pipe is lifted out, the 5-meter long steel drill is used for manual cleaning, the steel drill can possibly fall into the lower combustion chamber by a little carelessness, and furthermore, the operation is performed under the condition of not stopping the kiln, so that the safety of operators is seriously endangered, and meanwhile, the continuous operation of the annular sleeve kiln and the yield of finished lime are also influenced.

The following are the causes of injector clogging:

because the limestone has higher sodium and potassium contents in limestone ores in partial areas, the inorganic compounds containing sodium and potassium volatilize sodium and potassium steam at high temperature and are doped in circulating flue gas in the calcination process of the sleeve kiln.

In the annular sleeve kiln, the temperature of the driving air is 400 ℃, the temperature of the circulating smoke is 800 ℃, and the temperature of the mixed gas of the driving air and the circulating smoke is about 700 ℃, so that the sodium and potassium vapor in the mixed gas is condensed when the circulating smoke passes through the horn-shaped inlet pipe of the ejector. This portion of the condensed sodium and potassium will adhere to the inner walls of the trumpet inlet pipe and the mixing tube of the eductor and combine with other inorganic compounds in the circulating flue gas to form a low melting eutectic, increasing the surface tackiness of the inner walls of the eductor inlet pipe and mixing tube. Fly ash in the circulating gas is deposited there by the viscosity of the inner wall surface when passing through the inner wall of the mixing tube. As the process progresses, new sodium and potassium vapors continue to condense there, causing more fly ash to settle, forming a vicious circle. When the phenomenon is serious, the effective negative pressure area of the ejector is reduced, so that the circulation air quantity of the whole kiln body is influenced, the cooling air quantity at the bottom of the kiln is reduced, the ash outlet temperature is increased, and the heat consumption is increased.

For this reason, each production unit has been searching for a solution to thoroughly solve this problem.

The invention comprises the following steps:

to overcome the above-described clogging problems, it would be advantageous to provide an injector for an annular sleeve kiln with a gas combustion function to increase the temperature of the mixed gas.

To this end, the invention provides an injector for an annular kiln comprising an ejector tube for conveying drive air, a trumpet-shaped inlet tube for receiving circulated flue gas, a mixing tube for forming a mixture of drive air and circulated flue gas therein, and a diffuser tube located below the mixing tube, the injector for an annular kiln further comprising an outer sleeve gas burner connected to the outside of the ejector tube, wherein the outer sleeve gas burner is arranged to receive gas from the outside and to combust the gas in the mixture of drive air and circulated flue gas.

Further, the outer sleeve gas burner is welded on the outer part of the injection pipe in a sealing way.

Still further, a plurality of gas nozzles are uniformly arranged on the lower end surface of the outer sleeve gas burner along the circumferential direction.

Further, the outlet direction of the gas nozzle is consistent with that of the injection pipe.

Further, the outer sleeve gas burner is provided with a gas inlet.

Further, a circulating flue gas inlet is arranged on the trumpet-shaped inlet pipe.

Compared with the prior art, the invention has the advantages that the outer sleeve gas burner is additionally arranged, so that gas can be burnt in the mixed gas of the driving air and the circulating flue gas, heat is released to improve the temperature of the mixed gas after the circulating flue gas and the driving air are mixed, and the temperature is higher than the condensation temperature (800 ℃) of sodium and potassium steam, so that the problem of blockage of the injector is avoided, the service life of the injector and the operation rate of the sleeve kiln are prolonged, the staged combustion of fuel can be realized, the temperature uniformity of a combustion chamber under the sleeve kiln is favorably improved, the formation of a local high-temperature region is avoided, and the generation of thermal NOx is further restrained.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

Description of the drawings:

the structure of the invention, as well as further objects and advantages thereof, will be better understood by reference to the following description taken in conjunction with the accompanying drawings in which like reference numerals identify like elements:

FIG. 1 is a schematic view of an injector for an annular sleeve kiln according to an embodiment of the present invention;

FIG. 2 is a schematic view of the injector tube and outer sleeve gas burner of the annular sleeve kiln injector of FIG. 1;

fig. 3 is a plan view of the structure of fig. 2 taken along direction a.

The specific embodiment is as follows:

specific embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in fig. 1, and in combination with fig. 2 and 3, in the present embodiment, the injector for an annular sleeve kiln includes an ejector pipe 1, an outer sleeve gas burner 2, a trumpet-shaped inlet pipe 3, a mixing pipe 4, and a diffuser pipe 5. Wherein the ejector pipe 1 is used for conveying high-speed flowing driving air; the outer sleeve gas burner 2 is connected to the outside of the injection pipe 1, in particular to the outside of the injection pipe 1 in a sealing manner, a plurality of gas nozzles 25 are uniformly arranged on the lower end surface of the outer sleeve gas burner 2 along the circumferential direction, the gas nozzles 25 are consistent with the direction of the outlet 14 of the injection pipe 1, and a gas inlet 23 is also arranged on the outer sleeve gas burner 2; the trumpet-shaped inlet pipe 3 is used for receiving the circulating flue gas, and is provided with a circulating flue gas inlet 36; the mixing pipe 4 is used for forming mixed gas in the driving air from the injection pipe 1 and the circulating flue gas from the trumpet-shaped inlet pipe 3, and the diffusion pipe 5 is positioned below the mixing pipe 4.

Although the trumpet-shaped inlet pipe 3 is mentioned in the present embodiment, it should be understood that it may have other shapes as long as it ensures that the circulation gas smoothly enters therein and converges into the mixing pipe 4.

As shown in fig. 1 and 2, the outer casing gas burner 2 is constructed such that a part of the gas originally entering the annular sleeve kiln from the lower combustion chamber of the annular sleeve kiln is distributed to the outer casing gas burner 2 through the gas inlet 23 thereon to be burned, and is sprayed out through a plurality of gas nozzles 25 located on the lower end surface of the outer casing gas burner 2 to burn the gas in the mixed gas of the driving air and the circulated flue gas, thereby releasing heat, which increases the temperature of the mixed gas of the circulated flue gas mixed with the driving air (the temperature of the flue gas mixed with the driving air in the prior art is only 700 ℃) to be higher than the condensation temperature (800 ℃) of sodium and potassium vapor, thereby avoiding the problem of injector clogging.

In addition, after the above-mentioned injector with gas combustion is adopted, a part of the gas originally entering from the lower combustion chamber of the annular sleeve kiln is distributed to the outer sleeve gas burner 2 for combustion, so that the staged combustion of the gas in the lower combustion chamber is realized. In this aspect, a part of the fuel gas burns in the trumpet-shaped inlet pipe 3 and the mixing pipe 4, so that a part of oxygen in the mixed gas is consumed, and the oxygen concentration in the lower combustion chamber can be reduced to below 15%; on the other hand, the temperature of the mixed gas entering the lower combustion chamber is increased, so that a high-temperature low-oxygen environment is formed in the lower combustion chamber, the fuel gas is subjected to a recombination process such as cracking in the high-temperature low-oxygen environment, a thermodynamic condition completely different from that of the traditional combustion process is formed, heat is released when the fuel gas is subjected to delayed combustion with the oxygen-deficient gas, a local high-temperature high-oxygen area in the traditional combustion process is not generated, and the generation of thermal NOx can be effectively restrained. This combustion is a dynamic reaction, without static flame, and is a flameless combustion process.

In summary, after the injector with gas combustion is used on the annular sleeve kiln, the injection efficiency is improved, the secondary air coefficient is reduced, and the injector scaling phenomenon is obviously improved. More importantly, the stable operation of the ejector can enable the annular sleeve kiln to form a stable parallel flow calcining zone, the quality of calcined products is improved, the heat accumulator in the kiln is increased, the kiln top and the ash discharge temperature are reduced, and therefore the heat consumption of the system is lower.

While the technical content and features of the present invention have been disclosed above, it will be understood that various changes and modifications to the above-described structure, including combinations of technical features individually disclosed or claimed herein, and other combinations of these features as apparent to those skilled in the art may be made under the inventive concept of the present invention. Such variations and/or combinations fall within the technical field to which the invention relates and fall within the scope of the claims of the invention.

Claims

1. An injector for an annular sleeve kiln comprising an ejector tube for conveying drive air, a trumpet-shaped inlet tube for receiving circulated flue gas, a mixing tube for forming a mixture of drive air and circulated flue gas therein, and a diffuser tube located below the mixing tube, characterized by further comprising an outer sleeve gas burner connected to the outside of the ejector tube, wherein the outer sleeve gas burner is arranged to be adapted to receive gas from the outside and to burn the gas in the mixture of drive air and circulated flue gas, said outer sleeve gas burner being provided with a gas inlet.

2. The injector for an annular sleeve kiln according to claim 1, wherein the outer sleeve gas burner is sealingly welded to the exterior of the ejector tube.

3. The injector for an annular sleeve kiln according to claim 1 or 2, wherein a plurality of gas nozzles are uniformly arranged in a circumferential direction on a lower end face of the outer sleeve gas burner.

4. An injector for annular sleeve kiln according to claim 3, wherein the gas jets are oriented in line with the outlet of the ejector tube.

5. The injector for annular sleeve kiln according to claim 1, characterized in that the trumpet-shaped inlet pipe is provided with a circulating flue gas inlet.